Nghiên cứu mồi bả diệt muỗi và kết quả khảo nghiệm phòng trừ muỗi truyền bệnh ở quảng bình luận án PTS sinh học62 42 10 01

Lan dau tien Laveran 1880 &n thliy ky sinh triing sbt ret KSTSR trong mau ngoai vi cua mdt benh nhan ngubi Angieri Ronald Ross 1898 da xac dinh dugc vai tro tmyen benh ciia mudi Anophele

IIA Til! QUYEN

NGHIEN CUU M()I BA DIET MUOI VA KET QUA

KHAO N(,HIEM PHONG T R l / M u 6 l

TRUYEN BENH C* QUANG BINH

LUAN AN PHO TIEN SY KIIOA HOC S/NH HOC

HaNAi 1995

Trang

1

I^cVi ckm an

PHAN L MO DAU 2

PHAN n LONG QIJAN lAl LIEU 4

ILL VAI TRO TRUYEN BENH CUA MUOI CULICTDAE 4

11.2 D A C TfNlI SINTI HOC CUA MOT SO LOAl MUCTl

C 6 VAI T R 6 TRUYEN BENII, 10

11.2.1 Tap tinh hiit mdu cfia muoi 10

11.2.2 Tap tmh trii an ctrn muui 11

11.2.3 Sir khdng va trdnh tliuoc diet cia muoi 12

11.2.4 Noi sinh s&n cua muoi 13

1L2.5 Cdc yen to sinh thdi anh Iiu6ng den cdc quan the muoi

tiTTong thhnh 14

11.3.1 Bien phdp hda hoc 15 11.3.2 Bien phdp sinh hoc 20

11.3.3 C^c bien phdp thu (hap vk phong chong muoi khdc 21

11.3.4 Nhifng cong Irinh nghien ciiu ve muoi vk nhiJng hda

chat diet muoi chft ycu dri dirge si^ dung 6" Quhng Binh 22

PHAN ML

TIlOl GIAN, DIA DIEM v A PHUONG PIlAP

NGHIEN CUU 24

iii.L MOT SO D A C D I E M T U N H I E N V A K I N H T E X A

HOT d Q U A N G BINH CO LIEN QUAN DEN SU

III, 1.1 Dae diem dia l5^ tu nhien 24

I1L1.2 Dae diSin khf hau 27 I1LL3- Tmh hlnh kinh tc xa hoi 29

111.2 THOI GIAN v A DIA DIEM NGHIEN CUU 30

IIL3.1 Nghien cifu muoi 35 III.3.2.Nghien cifu dieu che vk ifng dung moi diet muoi 37

KET Q u A NGHIEN CUU VE MUCTl CIJUC1DAB6

Q U A N G B I N H 42

LI MUOI ANOPHEUNAE 42

L I l Thknh phan loki vk su phan bo 42

LI.2 Nhting h)hi muoi Anopheles thu thap duoc bang

phuong phdp moi ngudi ban dem 45

1.1.3 NhUng loki muoi Anopheles bat duoc trong nhk vho

ban ngky 46

LI.4 Mot so lohi muoi Anopheles thudng gap cd vai tr6

truyen benh 6* Qufing Binh 48

1.2 MUOI CULICmAE 53

L2.L Thknh phan loai vk su phan bo

L2.2 Su phan bo vk {^ le (%) cia muoi

Culex quinquefasciatus vk Culex tiitaeniorhynchus 54

1.2.3 Mat dp cua muoi Culex quinquefasciatus vk

Culex tiitaeniorhynchus 55

L2.4 Aedes aegypti, 58

C I I U a N G 2

NGHIEN CUU S A N XUAl MOI DIET MUOI 62

2.1 MUC DfCH NGHIEN CUU MOI B A DIET MUOI 62

2.2 CO S 6 KHOA HOC CUA VIEC DIEU CHE MOI

DIET M U O l 66 2.3 XAC DINH CONG THUC, QUY T R I N H S A N X U A I

MOI DIET MUOI 68

2.3.1 Xdc dinh thhnh phan moi diet muoi 68

2.3.2 X^c dinh loai hda chat diet con titing trong

moi diet muoi 73 2.3.3 Cong thifc dieu die vk quy trinh sJin xuat

moi diet muoi 77 2.4 SU DUNG VA B A O Q U A N MOI DIET MUOl 79

2.5 DOC TfNH CUA MOI DIET MUOl DOl VOI MUOl,

2.5.1 Doc tmh cfia moi diet muoi doi vdi muoi 81

2.5.2 Doc tinh cua moi diet muoi doi vc^i ngud-i vk dgng vat 83

C H U Q N G 3

HIEU LUC CUA MOI DIET MUcTl IRONG DIEU KIEN

3.1.1 Hieu krc cua moi diet muoi doi vdi muoi An vagus 85

3.1.2 Hieu luc cha moi diet muoi doi vdi muoi

Aedes aegyqyfL 86

3.1.3 Hieu luc ctia moi diet muoi doi vd-i muoi

Cule^ quinquefasciatus 87

3.1.4 D^nh gid su thu hut cua mh\ diet muoi vk dgng vat

moi doi vdi muoi 89

3.2 HIEU LUC CUA MOI DIET MUOl TRONG

PHAM VI THUC DIA HEP 91

3.2.1 a Qu&ng Binh 91 3.2.2 O H ^ N g i - 92 3.2.3 Thii nghicm xde dinh thdi gian tdc dung ton luu ciia

moi diet muoi tai thue dia 94

3.2.4 So sanh mat do muoi dot ngud'i o noi cd dilng moi vk

noi khdng diing moi 100

3.2.5 Thanh phan lohi muoi bi thu hiit vh diet 105

3.2.6 Tde dung diet rudi cua moi diet muoi 106

C H U O N G 4

KET QuA K H A O NGHIEM UNG DUNG

MOI DIET MUOI 110

4.1 TINH HINII SU DUNG MOI DIET MUOl TRONG

CONG DONG 113

4.2 SU DANH GIA VA CHAP NHAN CUA NHAN DAN

VE VIEC s u DUNG MOI DIET MUOI 113

4 3 CAC CHi SO MUOI v A BO G A Y ^ 114

4.3.1 Kct quh dieu tra chi so eon trung cV hai diem

(hi nghiem vk doi ehiing tru(fe khi dat moi 115

4.3.2 Chi so muoi trong thdi gian thi nghiem

dting moi diet muoi 116

4.3.3 Chi so bp gay Aedes aegypti 124

PHAN V KET LUAN 129

M6 DAU

Mu6i la vit tmng gian truyen nhifeu b^nh nguy hiem nhu sot ret, sot xuat huyet, viem nao Nhat Ban B, giun chi bach huyet Do c6 tam quan trong dac biet do, nen da c6 nhieu cong trinh nghien cuu ve khu he, sinh hoc, vai tro tmyen benh va bien phap phong diet mu6i Cac ket qua nghien cuu khoa hoc da gop phan giiip cho loai ngucd vugt qua dugc thtr thach cua nhihig tham hoa dich benh nhu sot ret, sot xuat huyet, viem nao Nhat Ban B

[88]

O nucfc ta, tiJ nhiing nam dSu cua the ky 20 da c6 nhirng nghien cuu v'h

mudi nhu cua Laveran (1901), Stanton (1926), Morin (1930) Nhung nghien cuu ve mu6i dugc thuc hien mot each c6 he thong a Viet nam c6 the ke tif sau nam 1954 va dac biet dugc day manh ti^ khi Vien Sot ret, Ky sinh triing - Con triing dugc thanh lap (1957) Nhiing cong tiinh nghien cuu ve mudi c6 gia tri dugc cong b6 nhu cua Dang Van Ngir va cong su (1973) [34], Vu Thi Phan va cong su (1975 [36], Nguyin Hio Viln, Tran Dure Hinh va c6ng su (1975) [63] Cac nghien cuu chu yen tap trung vao viec xac dinh thanh phan loai, su phan b6, xac dinh vai tro tmyen b6nh ciia mot s<5 loai muoi quan trong trong nude, trong tijfng khu vuc va nghien cuu ap dung cac bien phap diet vao thuc ti^n Viet nam

D5i vdi viec phong tru mudi trudc day cung nhu hien nay, bien phap hoa hoc vin dugc coi la mot bi^n phap c6 hieu qua cao nhat Cac hoa chat diet mudi chu yen dugc diing duai dang phun ton luu, phun khdng gian, tam man, huong xua di^t mudi, kern bdi xua (Tran Diic Hinh, 1992) [U], Qua trinh thuc hi^n phirang thuc phun ron luu hoa chat diet da xu^t hien mot kho

su, 1980) [1,37] Di&u nay la mdt trong nhiing nguy^n nhan khdng hoan thien

trong cdng tac phong chong sot ret of mdt s6 nudfc (Bmce Chwatt, 1980) [72]

Hudtig nghien cuu tim nhiing bi^n phap moi b6 sung nhu bi^n phap sinh hoc, biy mudi, hoac hoa chat diet mcfi, ciing nhu cac phuang thiic su dung hoa chat diet khac vin la m<5i quan tam hang d&u di5i vdi cdng tac phong ch6ng mudi truyen benh

Quang Binh la mdt tinh c6 dac diem dich tl hoc ciia cac benh do mudi tmyen kha dien hinh Tinh hinh sot ret diln bien tuong d6i phiic tap, dich sd't xuat huyet Dengue vin thu5ng xay ra, viing luu hanh benh giun chi bach huyet kha rong [43, 44].Vi vay v i ^ nghien cuu mudi noi chung, nhiJng loai mudi CO vai tro tmyfen benh quan trong noi rieng da dugc Tram Sot ret - Ky sinh triing - Con triing Quang Binh thuc hien thuong xuydn Trong do viec di6t mudi bang moi ba da dugc nghidn cum tir nam 1991 [15], la mdt phuang thiic mcfi su dung hoa chat diet bang phuang tien mbi di^t mudi Vcd nhimg

so lieu thu thap dugc trong qua trinh tham gia thuc hien, sau khi phan tich xu

ly chiing tdi t6ng ket thanh luan an vol tieu de: "Nghien cuu mbi ba diet mudi

va ket qua khao nghiem phong tnr mudi tmyen benh d Quang Binh"

Ndi dung chii yen ciia lusin an gbm:

* Xac dinh thanh phan loai va su phan bd ciia mot so loai mudi c6 vai tro

dich t l quan trong a Quang Binh

* Nghien cuu dieu che, san xuat mbi diet mudi

* Danh gia hitu qua ap dung mbi diet mudi trong viec phong chbng mdt so loai mudi c6 vai tro tmyen benh quan trong a Quang Binh

* Kien nghi ap dung phuang thurc mcfi diet mudi tmy'^n benh bang mbi ba

TONG QUAN TAI LI$U

ILL VAI TRO TRUYfiN B$NH CUA M u 6 l CUUCIDAE

Bdnh sot ret dugc biet den tir xa xua va luu hanh rdng tren the gicfi,

htnh xuat hito h^u nhu khip cac ch^u luc B6nh sbt ret gay nhi^u tac hai dbi

vdi siic khoe con nguci, doi vdi kinh te - xa hdi [84] Nhung nam 1950, tren th6' gidi hang nam cd sb ngucri mac b^nh sbt ret ucfc tinh khoang 250 trieu nguci, sb nguci chet vi sd't ret khoang 2,5 trieu ngubi (Bruce Chwatt, 1980) [71] Lan dau tien Laveran (1880) &n thliy ky sinh triing sbt ret (KSTSR) trong mau ngoai vi cua mdt benh nhan ngubi Angieri Ronald Ross (1898) da xac

dinh dugc vai tro tmyen benh ciia mudi Anopheles va chu ky phat trien ciia

KSTSR trong ca the mudi va benh sbt ret dugc lan tmy^n tiJ nguci benh sang

ngubi lanh qua mudi Anopheles [35,47,85], Til dd da ma ra mdt thci ky mci dbi

vdi viec nghidn cuu mudi sbt ret Hang loat cac cdng trinh nghien ciiu vfe khu h^, sinh hoc, sinh thai hoc, vai tro truyen benh va bien phap phong diet mudi

da dugc tien hanh [96.98, loi, 103,104,105,106,107]

Chi tinh rieng ve p h ^ loai mudi sbt ret da cd hang tram cdng trinh nghien ciiu vci gan khoang 300 bang dinh loai khac nhan Ten tubi cac nha khoa hoc: Leicester (1908), Stanton (1912), Reid (1968), Harison (1975) Stojanovich va Scott (1966), Theobald (1901-1910),, dugc biet den vdi cac cdng trinh nghien cuu ve mudi sbt ret a An Do Mien Dien, Inddnexia, Hiilippin, Thai Lan, Tmng Q u b c , [77, 82.102.109 no, iii] Nghien curu ve sinh hoc, sinh thai hoc cua mudi cd rat nhieu cdng trinh, trong sb do cd cac cdng trinh dang chu y nhu ciia Leicester (1903) [81 82], Bmce Qiwatt (1980) [70

71] Su nhay cam cua cac loai Anopheles vdi DDT va cac loai thuoc diet con

172] Herath va Davidson (1980) [78], Suarez (1990) [108], WHO (1981) [i 18]

^ O Vi^t nam benh sbt ret luu hanh tren 3/4 lanh tho, vci hang trieu nguci mac benh mdi nam (Dang Van Ngtr va cdng su, 1973) [34], Tir dau the

ky 20, d nude ta da cd nhiJng cdng trinh nghien ciiru mudi nhung chii yen do ngudi nude ngoai thuc hien laveran (1901) da nghien curu d Bac bd; Bonet (1906), Morin (1930) nghien ciin mudi d mot sb diem thudc dbng bang Nam

Bg va Cdn Dao [27] Sau nam 1957 Vien Sbt ret, Ky sinh triing - Cdn trung (Ha ndi) da cd nhieu cdng trinh nghien ciJu difeu tra ca ban mudi sbt ret tren

dien rdng toan mien Bac, Sb loai mudi Anopheles phat hien dugc la 56 loai

(Tran Due Hioh, Nguyin Due Manh, 1983) [8,9] Cac nghien cuu da xac dinh

dugc loai An.minimus la trung gian tmyen benh sbt ret d vung rung niii Viet

nam, Nhieu cdng trinh nghien cuu sinh hoc sinh thai hoc ciia mudi

An.minimus da dugc cdng bb: Nguyin HiJu Dire va cdng su (1973) [4],

Nguyen Diic Manh (1987) [27], Mudi An.balabacensis (hien nay ggi la

An.dirus) dugc xac dinh la tmng gian tmyen benh sbt ret chu yeu d vimg

rimg ram, rittig cd tan (Dang Van NgiJ, Vu Thi Phan va cdng su, 1985) [38] Ngoai ra cdn cd 7 loai mudi Anopheles khac ddng vai tro la vecta phu, tmyen benh sbt ret d mdt sb viing: An.sinensis tmyen P.vivax d Gia Ninh, huyen

Quang Ninh, tinh Quang Binh (Nguyin Tho Viln, Nguyin Due Manh va

cdng su, 1975) [63] Muoi An.sundaiods la tmng gian tmyen sbt ret chii yeu d

viing ven bien mien Nam (Nguyen Tho Viln, Nguyin Diic Manh va cdng su, 1985) [66] Cac cdng trinh nghien cuu bi^n phap phong chdng mudi sbt ret Cling da dugc tien hanh va dat ket qua: Vii Thi Phan, Tran Due Hinh va cdng

su (1980) [37]; Nguyin Van Chi va cdng su (1987) [i], C5 Mien Nam, theo

• cdng bb ciia Nguyin Thugng Hien (1968) cd 43 loai Anopheles O Tay

Nguyen cd 38 loai (Nguyin Due Manh, 1987) [27],

• Mac dii viec nghien cuu mudi ndi chung va mudi sbt ret ndi rieng dugc tien hanh cham hon so vdi cac nhdm ddng vat khac, nhung phai thira nhan rang ve liiih vuc nay nhanh chdng dugc nhfeu nha klioa hoc tham gia va nghien cuu

S6t xuat huybt Dengue thudng dugc goi la sbt xuat huyet Tu han mot thb ky trudc da cd benh Dengue cb dien, benh nay khdng cd ty le tu vong cao nhung sb ngudi mac rat Idn, Dengue cd kem theo xuat huyet ggi la Dengue xuai huyet (hoac sbt xuat huyet) Dengue xuat huyet do 4 tip ciia vims

Dengue (tip 1 den 4) thudc nhdm Arbovirus gay nen (Doan Xuan Mugu

1979), Day la mdt trong nhiing benh tmyen nhiem cd sb ngudi mac va ty le tir vong cao [33] Dengue xuat huyet phan bb d nhieu nude tren the gidi thudc Chau A, Chau P h i Chau My, nhung vimg Ddng nam Chau A la nai cd benh Dengue xuat huyet luu hanh nang nhat (WHO, 1986) [I2ij

Vu dich sbt xuat huyet dau tien dugc ghi nhan d Philippin nam 1953 Sau dd sbt xuat huyet xuat hien d nhieu noi: Thai Lan (1958), Malaixia,

Xingapo (1960), Inddnexia, Mien Dien (1981), 6 Cu Ba (1977 - 1980)

Dengue xuat huyet trd thanh dich Idn (Pham Song, 1991) [55], Nhieu cdng

trinh nghito ciiti mudi da xac dinh mudi Aedes aegypti ddng vai trd tmng

gian truyen benh Dengue xuat huybt: Plotnikov (1964); Pervomaiskyi, Podoliana (1974); Zdanop, Gaidavich (1977) (theo Vi5 Due Huong, 1984) [18] Nhieu nude da dua viec phong chbng mudi sbt xuat huyet thanh mdt chuang tiinh qubc gia, trong dd cd Xingapo, Thai Lan [76.121]

Song, 1991) [55], Tir nam 1960 benh Dengue xuat huyet xuat hien d mot sb dia phuang Mien Nam Nam 1969 dich sbt xuat huyet bimg phat d mot sO noi

nhu Ha Ndi, Hai Phong, Nam Dinh, Thai Nguyen, Nghe An [is] Tit dd benh

Dengue xuat huy^t cd xu hudng phat trien va nhieu nam da xay ra dich Idn Nam 1978 d Mien Bac cd 18.570 ngudi mac benh 89 ngudi chet Nam 1990

cd 75.310 ngirdi mac benh, 102 ngudi Nam 1987 Viet Nam cd 354.517 ngudi mac b^nh va 1,566 ngudi bi ch^'t [62],

Theo bao cao ciia Vien ve sinh dich tl (1993): Benh Dengue xuat huyet phan bb rdng d cac quan , huyen, thi xa, thanh phb va mdt sb viing ndng thdn trong ca nude Dengue xuat huyet dugc coi la mdt trong sb 10 benh tmyen nhilm cd ty le tu vong cao nhat d Viet nam [62],

Vai trd chii ybu tmyen benh Dengue xua[t huy^'t d Vidt nam la mudi

Aedes aegypti Nhieu cdng trinh nghien ciiu ve loai mudi nay da dugc cdng

bb nhu Vii Diic Huang (1984) [18]; Vii Dure Huong (1987); Le Khanh Thuan

va cdng su (1980 - 1989); Hoang Thiiy Nguyen va cong su (1986 - 1991); Nguyin Thi Bach Ngoc, Truong Quang Hoc (1993) [32, 33], Vii Sinh Nam (1995) [30] va nhieu cdng trinh khac Kbt qua nghien ciru ciia cac tac gia da khai quit dugc viing phan bb, vai trd dich tl, sinh hoc va cac bien phap

phong chbng mudi Aedes aegypti d Viet nam, gdp phan tich cue trong cdng

tac phong chbng sbt xuat huybt Hidn nay bfnh sbt xu^t huyet v5n dang la mot van dS quan tam ciia xa hdi

Viem nao Nhkt Ban B (VNNBB) la mot b^nh nghiem trong xay ra tai

cac nude Viln ddng, Nam A va Ddng Nam A Benh cd ty le tir vong cao Neu bdnh nhan hoi phuc dugc thi de lai di chung nang ne ve than kinh va tam

than Tac nhan gay benh la vims '^/N'NBB O An Do, vu dich dau tien xay ra vao nam 1952, vims viem nao Nhat Ban B dugc phan lap tir mudi nam 1955

va tir ngudi nam 1958 (Schgal, 1989) Tir nam 1970 d An Do benh lan rdng

va trd nen tram trong Nam 1980 cd 3.478 ngudi mac va 1.405 ngudi chet Chinh phii phai dat van de nay thanh mdt nhi^m vu trong ybu trong viec bao

yt sue khde cdng dbng Cac tac gia d An Do da xac dinh dugc 11 loai mudi

thudc 3 gibng: Culex, Anopheles, Mansonia ddng vai trd tmng gian tmyen benh VNNBB, trong dd Culex tritaeniorhynchus la loai quan trong nhatt (Schgal, 1989) [99], 6 Inddndxia, Thai Lan, Nepan, Nhat Ban , benh VNNBB

Cling la mdt van de dugc nhieu tac gia nghien cuu [92,123,124] Leake va

Johnson (1987) [83] da phan Mp dugc vims VNNBB tir mudi Culex

tritaeniorhynchus ddng vai trd chinh tmyen benh VNNBB d cac viing da

b^nh thudng xay ra tijr thang 4 den thang 9 (Nguyin Thi Bach Nggc j 1995)

[33]

hdi rdng B^nh do 3 loai giun chi Wuchereria bancorofti, Brugia malayi,

Brugia timori gay nen, Benh giun chi bach huyet thudng luu hanh d cac nude

nhiet dcd thudc chau A, Chiu Phi, Qiau My va mdt sb dao d viing Thai Binh Duangtiu] Benh nay khdng nhiing chi anh hudng den siic khde con ngudi

ma cdn de lai nhiing di chung nhu viem bach mach, phu voi Ky sinh triing dugc tmyen tir ngudi benh sang ngudi lanh qua mudi (Nguyin Duy Toan,

1987) [52, 53] Manson (1978) phat hien thay an triing giun chi Wuchereria

bancorofti phat trien trong ca the mudi va au triing thanh thuc cdn thoat ra

khdi vdi cua mudi Culex fatigans Tren the gidi cd khoang 3.287 trieu ngudi

sbng trong viing cd benh giun chi bach huyet luu hanh [53]

(J Vi6t nam giun chi bach huyet luu hanh d hau het cac tinh tiiudc viing dbng bang Bac bd nhu Nam Ha, Hai Hung, Thai Binh, Ha Ndi, Ha Tay,

Ha Bic, Quang Ninh va Quang Binh [57] Benh giun chi bach huyet d Viet nam thudng de lai di chiing phii d chan nen nhan dan thudng ggi la benh chan voi Mathis va Leger (1911) da nghien cuu benh nay, thir man cho gan

2000 ngudi thudc 10 tinh dbng bang Bac Bd va thay ty le nhilm au trung giun chi trong mau ngoai vi la 4,69% Sery va Pham Van Ndng (1960 - 1975)

da phat hi^n d Hai Duong ty le nhilm au triing giun chi la 15% Theo Nguyin Duy Toan (1985) [52] thi tif nam 1960 - 1975, ty le nhilm au trimg giun chi chung ciia Mien Bac la 6,01%; O Quang Binh ty le nhilm au thing giun chi la 11,7% Quang Binh cd khoang 40.000 ngudi sbng trong viing cd

benh giun chi luu hanh va ty \t nhilm au trung d 2 xa Hai Ninh va Gia Ninh

huyen Quang Ninh la 2,30% [44] O Mien Nam benh giun chi bach huyet khdng dang ke [53] Nhieu cdng trinh nghi6n ciiu lam sang va dfeu tri benh giun chi bach huyet da dugc cdng bb nhu Dang Van Ngii va cong sir (1960,

1965), Bach Qubc Tuyen (1963) [33] Cac nghien ciiu ve mudi da xac dinh

dugc vai trd tmyen benli giun chi d Viet nam la Culex quinquefasciatus,

Mansonia annulifera, Anopheles sinensis (Tran Diic Hinh, Nguyin Bach

Nggc, Vu Diic Huong, 1987) [lO] Cho d^n nay d Viet nam mdi chi gap 2 loai

giun chi bach huyet la W.bancrofti va B.malayi, trong sb dd B.malayi chiem

X&i 95% (Nguyin Duy Toan, 1987) [53]

IL2 DAC TINH SINH HOC CUA MOT s d LOAI M u 6 l CO VAI TRO

TRUVfeN B$NH

n 2 1 Tap tinh hiit mau ciia muoi

Pha trudng thanh la giai doan sbng tren can duy nhat trong vong ddi cua mudi Mudi due khdng hiit mau, chi sir dung ngudn thiic an tu nhien nhu mat hoa va dich trai cay, nhua cay lam ch^t dinh dudng Mudi cai hiit mau ddng vat va ngudi, dd ciing la chat dinh dudng bat budc de nudi ca th^ va phat trien tning Khdng hiit mau thi mudi khdng the thuc hien dugc chu ky sinh tmdng binh thudng Mdt sb nghien ciiu (Bmce Chwatt, 1980) [71] da neu len rang: Mudi cai ciia hau het cac loai it nhat phai hai lan dbt mau thi Id tning dau tien mdi phat trien dugc Nhiing chu ky tiep theo thi sau mdi lan hut man mudi lai de tning Mudi cai thudng dbt ddng vat man ndng, lugng mau tieu thu dugc khoang bang trong lugng ca the mudi Mau trong da day mudi dugc tieu hda trong mdt vai ngay (Bmce Cliwatt, 1980)

Mudi CO \Mi lua chgn vat chii, Nhiing loai mudi khac nhau thi khac

nhau ve ai tihh vM chii Trong dieu kien thuan Igi mudi cd the lua chon vat chu thich hgp nhat, nhung trong nhung dieu kien khdng thuan Igi mudi cd the thay dbi vat chii Mot sb loai thich vat chii la ngudi nhung ciing cd the hiit mau dgng vat hoac agugc lai Trong thuc te cdn cho thay rang tham chi mudi

cai CO dii hut audc dudng trong dieu Icien bat bucc de duy tn sir song Trong

so nhimg yen to thu hiit mudi cai den vat chii thi nhiet do, miii vi, lugng CO2

la quan trong (Bmce Chwatt, 1980) Yeii to nay cd th^ thu hut dac biet dbi vdi loai mudi nay nhung dbi vdi loai mudi khac thi it hon Cac dgng vat khac nhau cd su thu hiit mudi khac nhau Mdi loai mudi cd thdi gian hoat ddng tim

mbi khac nhau, Mudi Anopheles va muoi Culex thudng dot mau vao ban dem, mudi Aedes chu yeu hiit man vao ban ngay Khi mudi dbt, dich trong

tuy6i nude bgt ciia mudi dugc tmyen qua vat chii, lam tang qua trinh chay mau trong mao quan Vi vay viec dbt mau vat chu la nguyen nhan de mudi ddng vai trd tmng gian tmyen benh cho ngudi va ddng vat (Bmce Chwatt, 1980)

IL2.2 Tap tinh tru an ciia mudi

Sau khi giao phbi mudi tim mbi hiit mau rbi tim noi tni an de tieu mau

va phat trien tning

Noi tni an cua mudi rat da dang, tiiy theo cac loai mudi khac nhau ma

cd nhiing noi tni an khac nhau [69] Cd nhihig loai tim mbi hiit mau trong nha rbi nghi lai d trong nha Mudi cd thi d^u vao tudng vach, vach ngan, quto ao treo trong nha, bb thdc, mat sau ciia tii, tranh anh, chan bat Trong thuc te thudng bat gap mudi dau d do cao dudi 2 met NTiimg vimg cd phun DDT d

do cao tir 2 met trd xubng, da thay hien tugng mdt so loai mudi Anopheles tni

an d trong nha tranh thudc diet bang each dau d nhiing noi cao han, nai khdng cd hda chat diet (Nguyin Diic Manh, 1993) [28] Ciing cd nhiing loai tim mbi hiit mau trong nha rbi bay ra tni an ngoai tu nhien, hoac ngugc lai

Nai tiL m cua mudi d ngoai thien nhien thudng la cac biii cay, hoc cay, r l cay Idn, ham ho, '.e aiit cua aui da Tliirdng muoi iyu dau y aoi Ididng c6 <inh

sang mat trdi doi tnrc tien, c6 do im dam bao, c6 vi khi hau thich hgp "^-/ao

miia he mudi thudng tim nai tni dau thap c6 nhiet do thap, do am cao Dudi tac dung cua viec diing hda chat diet mudi da dan den mdt sb loai muoi thay dbi tap tinh tni an von cd cua minh de phii hgp vdi dieu kien mdi trudng sbng

nhu An.minimus d Mien Bac da cd hien tugng tranh DDT, thay dbi t^p tmh tni an trong nha ra tim nai tni in ngoai nha (Nguyen Diic Manh, 1993) [28]

II.2.3 Su khang va tranh thuoc diet cua muoi

Su khang cac loai thuoc diet cdn triing dugc coi nhu la mot hien tugng sinh hoc ciia muoL Hien tugng sinh hgc nay dugc hinh thanh do viec su dung khdng hgp ly hda chat diet mudi (Bmce Chwatt, 1980) [72]

Khi mdt quan the cdn triing tiep xiic vdi mdt hgp chat doc thi se cd

mdt phan chet mot phan cdn sbng sdt lai Hien tugng dd goi la Idiang sinh

ly Be ngoai ciia hien tugng nay la su thay doi tap tinh ciia quan the cdn

triing, bdi the ma chiing c6 kha nang tranh tiep xiic vdi thudc diet Hien

tugng nay ggi la Jdiang tap tinh hay tranli thudc (Bmce Chwatt, 1980) Ca hai loai khang thubc deu cd the han che ket qua cua cac bien phap phdng chbng,

dac bi^t la bien phap phun thubc didt cdn trimg cd tirih chit fdn luu

Nhieu nghien ciiu (Herath va Davidson, 1980; Bmce Chwatt, 1980) [72

78] Cling da cho biet ban chat va ca che ciia su khang thubc la vai trd ciia cac

yeu tb di tmyen, yeu to tac ddng va yeu to sinh hoc Su khang thudc tang len trong qua trinh chgn Igc va chi xay ra d mot sb loai mudi ma ngay tir dau da

cd mdt ty le ca the mang tmh di tmyen cd kha nang ciio'ng lai doc to cua

thudc diet, Nhirne ca the nhay thi chet nhuns en the c6 kha nan« chbnii lai thudc diet thi sdn,s sot '/n phat trien ^•Ing len ra'i nhanh Dea xxict giai doan nao do quan the nnuoi chi cdn lai ahirng ca the khang thudc hoan tokn

Theo thong ke ciia WHO (1977) thi nam 1944 tren the gidi mdi chi cd

2 loai Anopheles khang DDT Nam 1976 cd 43 loai Idiang vdi mdt hoac

nhieu loai hda chat diet Mdt so nude da thay bang cac loai hda chat diet thudc nhdm Phbt pho hiiu ca (Malathion) va nhdm Carbamat Tuy nhien sau

dd ciing xay ra hien tugng mudi khang vdi cac loai thubc diet nay Tinh den

nam 1992 tren the gidi cd Idioang 45 loai mudi Culicinae khang vdi mdt sb

hda chat diet (WHO, 1992) [33],

O Viet nam cd nhieu cdng trinh nghien ciiu miic do nhay cam vdi cac loai thubc diet trong qua trinh phdng chbng mudi tmyen sbt ret, sbt xuat huyet viem nao Nhat Ban, giun chi Cd the neu dien hinh mdt so cdng trinh nhu Vii Thi Phan, Nguyen Van Chi, Nguyin Xhan Dinh, Nguyin Thi Phiic va cdng su (1980) [37]; Nguyen Van Chi, Nguyin Xuan Dinh (1981 - 1985) [i]; Thdng bao ve tinh hinh khang tliudc diet ciia muoi d Binh Tri Thien ciia Ha Thi Quyen (1987) [42] Trinh Dinh Dat va cdng su (1993) da nghien ciiu xac dinh miic do va dac diem di tmyen khang thudc trir sau cua mudi

Cx,quinquefasciatus [2, 3] fCet qua nghien ciiu ke tren deu thbng nhat nhan

dinh rang d Viet nam da cd mdt sd loai mudi Anopheles, Culex, Aedes cd hien tugng khang hda chat diet nhu An.vagus, An.sinensis, An.sundaicus,

Aedes aegypti, Culex quinquefasciatus, Culex tritaeniorhynchus M6t sb loai

xuat hien tap tinh tranh thubc diet, trong sb dd cd An.minimus da duac

nghien ciiu rat ky ludng va the hien tap tinh nay kha rd rang (Nguyin Tho Viln, Nguyin Diic Manh va cdng su) [64,65]

IL2.4 Noi sinh san ciia mudi

Tning mudi ludn ludn dugc de trong mdi tmdng nude Nhiing yeu tb lien quan tdi nai sinh san cua mudi bao gbm nude, anh san", nhiet dd, dd

man lugng chat huii ca ddng chay, thuc vat thiiy sinh , tuy theo timg loai mudi va su thich nghi cua chiing vdi nhimg dieu kien mdi trudng Nhung nai sinh san ciia mudi thudng gap d nhung subi chay cham, dam Fay, ao ho, gieng, vung nude dgng tren ddng mdng, mgng liia, hbc cay, be chiia nude, vet nude dgng tren dudng, cac dung cu phe lieu cd chiia nude v.v Hau het cac loai mudi deu cd cac giai doan tir tning phat trien thanh bo gay rbi phat trien dianh quang deu xay ra d trong nude Mdt chu ky tir tning den mudi

tmdng thanh ciia mudi Anopheles khoang 7 - 8 ngay d nhiet do 31°C va 20

ngay d nhiet do 20°C Tuy nhien mdi loai cd mdt gidi han nhiet do thich hgp Nhung vat chiia nude nhan tao nhu Ig, chau, thiing p h i Ibp d to hdng cd chiia

nude thudng la noi thich hgp cho mudi Aedes de tning, trong liic mudi Culex

quinquefasciatus lai thich de tning d nhung cdng ranh trong mdi tmdng dd

thi noi cd lugng chat hiiu ca nhieu (Bmce Chwatt, 1980) [i]

Viec kiem soat mdi tmdng sinh san ciia mudi va can thiep bang nhiing bien phap thich hgp trong giai doan phat trien trong mdi tmdng nude cua mudi cd y nghia lam giam mat do quan the mudi tmdng thanh

IL2.5 Cac yeu tb sinh thai anh hudng den cac quan the mudi trudng thanh

Vong ddi ciia mudi cd bdn giai doan Giai doan tning, bg gay, quang hoan toan tdn tai va phat trien trong nude Giai doan tmdng thanh song tren can Ca bbn giai doan nay deu chiu anh hudng hoac true tiep, hoac gian tiep ciia cac yeu tb sinh thai bao gbm cac yeu tb tu nhien nhu nhiet dd, dd Eim, anh sang, nude, gid ma chung qui lai la thdi tiet, khi hau va mdi quan he giiia mudi va cac loai sinh vat khac Ngoai ra mudi cdn chiu anh hudng cua nhiing tac ddng do hoat ddng cua con ngudi gay nen nhu hoat dgng ndng ngiiiep,

thiiy Igi, dot rimg khai hoang, trong rimg, sir dung hda chat trong nong

nghiep, trong y hgc du phdng v.v , Nhiing yeii td tren quyet dinh su phan bb thanh phan loai, mat do cua mudi theo timg viing, dia phuang, timg sinh canh, anh hudng den su ton tai va phat trien binh thudng ciia mudi Qua qua trinh chgn Igc tu nhien ma ket qua la mdt sd loai mudi da thay dbi tap tinh von cd ban dau ciia minh de phii hgp vdi dieu kien mdi trudng song

Cung nhu cac loai con triing khac dbi vdi mudi thi thiic an, cu the la vat chii la nhan td quan trgng nhat anh hudng true tiep den sir siuh tmdng, phat trien va tap tinh ciia mudi 0 mudi su phat trien ciia tning gdn lien vdi dinh dudng cua con cai sir tieu mau song song vdi su phat trien ciia tning trong bubng tning Khdng hiit dugc mau thi tning khdng phat trien Sb Tan de tning CLia mudi tuong ung vdi sd lan hiit mau (Olxufev, 1940; Beklemisev, 1944) [46.75] Su bien ddng quan the cua mudi lien quan den cac dieu kien cu the ma quan the ton tai trong dd Viec sir dung hda chat trong ndng nghiep, thudc diet trong phdng chdng muoi la yeu td tac ddng manh me nhat den quan tlie mudi 1 ^ giam rd ret sb lugng ca the va thay ddi cua cac quan the mudi

II.3 CAC B I £ N PHAP D I £ T M U 6 I CHU Y^U

IL3.L Biep phap hoa hoc

I h e o W n O (1990 - 1991) thi trong cac bien phap phdng chbng mudi tmyen benh, bien phap hda hgc ddng gdp tich cue va cd hieu qua nhat Cd den hang tram hda chat da dugc nghien cini img dung dudi nhieu dang khac

nhau nhu phun tbn luu, phun Jdidng gian, tim man, tim rem huong xua diet

mudi kem bdi xua v.v,., [i 1.12.13.14.40.122] Cd the chia cac loai hda chat diet thanh cac nhdm sau

1 Nhdm Clo hiiu co

- DDT (Diclo diphenyl trichloroetan) la hgp chat dien hinh thudc nhdm

nay da dugc sir dung Nam 1948 Ponmuyle (1899 - 1965) da dugc trao giai thudng Nobel ve cdng lao phat hien tac dung diet cdn triing het siic cong hieu cua DDT

DDT CO thdi gian tac dung tbn luu dai he sb an toan la 67 nen to chiic

y te the gici (WTIO) da quyet dinh dua vao sir dung trong chuang trinh thanh toan sbt ret toan cau va da dat dugc ket qua het siic to Idn Sau chien tranh the gidi thii II, DDT dugc su dung rdng rai tren toan the gidi Nhd sir dung DDT ma hang nam da ciiu dugc hang chuc trieu ngudi khdi chet vi cac benh hiem nglieo nliu sbt ret, sbt xuat huyet, sbt vang Nhieu nude thudc viing dn ddi da thanh toan dugc benh sdt ret nhd sir dung DDT diet tmng gian tmyen benh [72,89], DDT dugc sir dung chii yeu dudi dang phun tbn luu vdi lieu lugng 2gAn" Viec su dung DDT chi sau mdt thdi gian ngan da xuat hien mudi khang loai hda chat nay va miic do khang tang dan len rat nhanh Dd la nguyen nhan chinli dan den tliat bai trong chuang trinh thanh toan benh sdt ret d nhieu nude (Herath va Davidson, 1980) [78]

Mat khac ciing nhan thay dugc rang DDT phan huy trong dat rat cham,

cd the tbn luu trong dat khoang 25 nam, cd the dugc tich liiy lai va dat ndng

do tang dan theo chudi thuc an tir thap len cao ciia sinh vat Trong vong 30 nam k^ tir 1942 tren the gidi da sir dung khoang 2 trieu tan DDT Qua kiem tra ngudi ta nlian thay DDT cd mat khap mgi noi ke ca trong mo md va sua ciia con ngudi DDT hda tan vao nude bien, tham nhap ca vao chun canh cut dt^in cue bac xa xdi (Bmce Chwatt, 1980) [72] Tii nam 1970 nhieu nude tren

the gidi trong dd c6 Lien Xd da bat dau cam s;in xuat va sir dung DDT

d Viet nam DDT dugc bat dau sir dung vao nam 1955 Nam 1962, DDT dugc dimg diet mudi trong chuang trinh thanh toan sdt ret d 28 tinh ciia Mien Bdc DDT da dugc sir dung trong mdt thdi gian rat dai (30 nam) vdi mot sd lugng rat Idn, hang ngan tan trong mdt nam, gdp phan dua lai ket qua dang ghi nhan trong chuang trinh phdng chdng sdt ret d Viet nam Cac cdng trinh theo ddi su nhay cam cua mudi vdi DDT dugc tien hanh rat kip thdi (tu 1962) va tliudng xuyen, da phat hien dugc mot so loai mudi khang DDT hoac

da tang siic d^ khang vdi loai hda chit nay Vi vay nhimg nam gan diy, DDT

chi cdn dugc sir dung d mdt sd viing mien niii va tmng du nai cd

An.minimus va An.dirus cdn nhay cam Hien nay dang cd xu hudng ngimg su

dung DDT trong linh vuc y hgc du phdng

2 Nhdm lan hiiu ca

- Malathion la hgp chat phot pho hiiu ca chinh dugc sir dung phdng diet mudi cd he sd an toan la 50 Malathion cd tac dung diet cdn triing manh, nhung tac dung tbn luu qua ngan, thudng chi keo dai tir 1 den 2 thang Vi vay Malathion chi dugc diing chbng dich d dang phun klidng gian Mdt sb loai mudi da khang loai^hda chat nay (Davidson, 1974) [74]

- Sumithion da dugc diing dudi dang khi diing de diet mudi Aedes

aegypti cung cd ket qua (Nguyen Thiiy Hoa, Nguyen Chac Tien va cdng su,

1992) [30],

3 NTidm Carbamate

- Hop chat chinh trong nhdm nay dugc sir dung trong viec phdng chdng vecta la Propoxur: 2 - M-Methylethoxy) phenyi methvlcarbamate (CAS) He sb an toan la 13 Propoxur tac ddng doc qua dudng tieu hda va tiep xuc, Nhieu nude da diing Propoxur de chbng dan dudi dang mdi 2% do

!rn \m:{'yv<ij-xx

L ^yy/^5s' sfefeM

doc tinh tieu hda Dang phun dung dich i% cd tac dung ton luu lau, dugc

diing de diet mudi m b i kien, ve va nhieu loai chan dot khac Vdi lieu lugng 2gym" phun ton luu tren tudng, Propoxur cd tac dung diet mudi trong 3 thang Propoxur cd doe tinh thap vdi ngudi vdi ddng vat cd vii, la hgp chat cd the thay DDT d nhiing nai da cd mudi khang Viec sir dung Propoxur chua rdng rai vi gia thanh cao va he sd an toan thap (Mohneaux va Gramiccia 1980) [73

86, 87] Propoxur cd tac ddng d at, hay cd doc tinh kicii diich budc cac loai con triing rdi khdi nai tni an va do dd tang su tiep xiic cua chimg vdi hda chat diet dugc phun len cac be mat Day la dac tinh khac biet vdi cac loai hda chat diet cdn triing khac

O Viet nam, Propoxur da dugc diing diet m b i dan dudi dang mbi doc 2% (Nguyin Chac Tien, Pham Thi Nggc Diep, Nguyin Thiiy Hoa, 1989) [49, 50] Chiing tdi chua thay cd tai lieu nao neu len sir dung Propoxur de diet mudi

4 Nhdm Pyrethroid

Qua danli gia cua WHO (1992) thay rang: Hien nay the gidi cd xu Iiudng sir dung cac hda chat diet thuoc nlidm Pyrethroid tong hgp dudi dang phun tbn luu, phun khdng gian, tam man, tam rem tam quan ao, huong xua diet mudi de diet mudi phun xudng nude de diet bo gay [14, 9i 95 lOO] Dac tinh chung ciia cac hda chat thudc nhdm nay la it doc vdi ngudi va ddng vat man ndng, cd hieu luc di^t cdn triing rat manh qua dudng tiep xiic va xdng hai, Chiing vira cd tac dung diet mudi tuc thdi vira cd tac dung diet tdn luu keo dai tir bdn den nam thang, viia cd tac dung xua dudi con trung rat manh

so vdi cac chat da sir dung, Cac hda chat tliudc nhdm nay deu hda tan tdt trong nude, trong cac dung mdi huu ca, dudi tac dung true tiep ciia anh sang

mat trdi ddc tmh bi giam nhanh Co the ke den mdt sd hda chat thudng dugc sir dung nhu:

- Permethrin: He sb an toan 516 Hinh thiic sir dung chii yeu la tam man, tdm rem vdi lieu lugng 0,2 - 0,5g/[n" 0 Viet nam bat dau sir dung Permethrin tir nam 1986 Da cd nhieu cong trinh nghien ciiu ung dung ttoi man Permethrin trong cdng tac phdng chdng sdt ret sdt xuat huyet, giun chi

khang dinh cd hieu qua rd ret, dac biet d nhimg viing cd muoi idiang DDT

(Nguyin Long Giang, Nguyin Thugng Hien, Pham Tlii Hda va cdng su,

1990 [5,6]; Vii Diic Huong va cdng su, 1993 [23]; Vii Sinh Nam, 1995 [30])

- Deltamethrin (K Othrine)

Tii nam 1977 den nay nhieu nude da ling dung Deltamethrin trong phdng chbng sbt ret dudi hinh thiic tam man hoac phun tbn luu tren tudng vach d Tmng Qudc sir dung Deltamethrin ttoi man vdi lieu lugng 25mg/m^

de phdng chdng sdt ret bao ve hang chuc trieu ngudi O Viet nam da cd nhieu cdng trinh nghien ciiu ling dung Deltamethrin dudi hinh thiic tam man vdi

litu lugng lOmg/m va phun tbn luu vdi lieu lugng 15mg/ni' thay cd tac dung

tdt vdi mudi tmyen sbt ret va sbt xuat huyet tren 5 thang Sir dung Deltamethrin dugc nhan dan hudng ling vi hda chat nay cdn diet duac rep, bo chet, dan, mbi va it de lai dau vet tren do vat Ciing nhu Permethrin, hien nay Deltamethrin dang dugc su dung rdng rai

- ICON (Lamdacyhalothrin)

I ^ hda chat diet cdn trimg manh, cd trien vgng ling dung rdng () Viet

nam Icon dugc sir dung dudi dang phun tbn luu vdi lieu lugng 30mg/ni^ d mdt sb viing dii diem va nhan th^y tac dung fdn luu keo dai 9 thang tren cac

loai vach g6, niia Dbi vdi tudng gach vdi tac dung tbn luu chi keo dai 1

thang Vi vay khdng nen sir dung Icon d nhiing vimg cd nhieu nha gach (Nguyin Thugng Hien, Nguyin Long Giang, 1993) [6]

II.3.2 Bien phap sinh hoc

Viec ap dung cac bien phap sinh hgc de phdng chdng mudi la mdt hudng chinh trong chuang trinh nghien ciiu mudi tmyen benh

Cung nhu cac loai cdn triing khac, trong ddi song tu nhien mudi thudng gap phai nhung thien dich khac kim ham su sinh san va phat trien cua minh Cac nha khoa hgc da di sau nghien ciiu linh vuc nay va da kham pha ra nhiing nhan td sinh hgc cd kha nang ung dung dugc trong viec phdng chdng mudi d ca hai giai doan tmdng thanh va bo gay dd la cac loai vi Jdiuan, virus, nam, ca v.v [68, 120] Trong mdi tmdng nude, cac loai ca gdp phan quan trgng trong viec diet bg gay cua mudi Costa va Femando (1975-1985) cho rang cd 3 loai ca cd kha nang diet bg gay d Srilanca lakhontov (1972),

Motabar (1975 - 1985) cho rang: Dang luu y han ca la ca Gambusia affinisis,

trong 24 gid mdi con ca cd the bat dugc 200 bg gay [25.46 68] Cac tac gia

cd cdng trong viec khing dinh kha nang diet bg gay cua Bacillus thuringiensis la Kramer, Garcia, Colwell, 1985 [80, 120] Uy ban bao ve mdi

tmdng cua My da nghien cuu kha nang gay benh cho mudi ciia nam Fungus

lagennidium gigantium Cdn cd rat nhieu cdng trinh nghien ciiu khac da va

dang tien hanh vdi nhiing khia canh khac nhau [68.97 ii7]

O Viet nam, viec phdng chdng mudi bang bien phap sinh hoc ciing da

dugc nghidn ciiu Nguyin Van Chi, Nguyin Thuy Hung va cong su (1987) da

xac dinh dugc 9 loai ca cd kha nang an bg gay va cd the ling dung trong cdng tac phdng chbng sbt ret Nguyin Thg Viln, T r ^ Dire Hinh (1990) cho thay

rang bang bifn phap tha ca chep lai Hung (Cyrinus carpio) kich tliudc tif 4

-6 cm vdi mat do tir 4 - -6 conAn^ nude, vao be nude an d nhiing vimg dbng

bang cd bg gay An.minimus da cd hieu qua lam giam mat do An.minimus rd

ret Nguyin Thi Bach Nggc, Tmong Quang Hgc (1993) [32] cho thay bien phap tha ca vao be nude va quan ly ve sinh mdi tmdng la rat cd hieu qua,

khdng chb den miic thap nh& mat dd mudi Aedes aegypti va chi sd Breteau

Nguyin Thuy Hiing va cdng su nghien ciiu diing che pham Bacillus thuringiensis, dau huang nhu de diet bg gay [17, 24j

II.3.3 Cac bien phap thu thap va phong chbng muoi khac

Trong thuc te mot sb bien phap phdng chbng mudi mang tinh chat tong hgp ciing dang dugc sir dung rdng rai nhu ve sinh mdi tmdng, khai thdng cdng ranh, han che nai sinh san ciia muoi, phat quang bin ram quanh nha, hun khdi diing huong xua diet mudi dimg binh xit cd hda chat diet mudi Bien phap diet mudi bang cac load biy anh sang, sdng sieu toi ciing da dugc ap dung

1 Bdy anh sang La loai bay diing ngudn anh sang vdi budc sdng thich hgp de thu thap mudi Hien nay cd nhieu loai bdy anh sang dugc san xuat d

My, Canada, Phap, Nhat, Nga v.v [i4]

- Bfiy New Jersey: Dung dien ludi Tmdc nam 1975 da dugc dung dat

cd dinh tai nhieu san bay d Mien Nam Viet nam de tlieo ddi sir giao luu cua mudi bang dudng hang khdng

- M y den CDC: Caay biuig acqui hoac pin, hien nay dang dugc diing nhieu trong nghien cuu thu thap mudi

2 Blv am dianh Do Ikesoji (1985) va Kmda (1988) phat nmih, Bily la

mdt he thbng gbm cd chudt lang, CO2 va sdng sieu am vdi budc sdng diich

hgp dugc phat ra tir mdt cai loa Bky dugc treo vao ban dem d do cao 1.5in de

thu thap mudi Cd the dieu chinh budc sdng phu hgp de thu thap dugc nhieu mudi due hay mudi cai [14.75,79]

Thongmngkiat (1990) nghien cini ling dung biy am thanh de phdng

chdng Culex tritaeniorhyncus d Thai Lan da cho thay vdi tan sb am thanli

530 Hz thu thap dugc sd lugng mudi cai nhien han ca (298 con mdt biy trong mdt dem) Mudi due thu thap dugc nhifeu d tan sd 350 Hz (43 con mdt bay, mdt dem) [i 12,113] (J Viet nam, chiing tdi chua thay cd tai Ueu nao cdng

bb ve viec nghien ciiu ling dung cac loai biy nay vdi muc dich han che mat

do quan the mudi chi thay ling dung biy den trong nghien ciiu dieu tra thu thap thanh phan loai

3, Ve sinh mdi tnrdng Mdt trong nhiing bien phap phdng chdng mudi

cd hieu qua ciing da dugc cong nhan la ve sinh mdi tmdng; Thau rira cac

dung cu cd bg gay Aedes de phdng chdng sdt xuat huyet Khai thdng cdng ranh de phdng chdng mudi Culex: Phat quang bui ram xung quanh nha d de

han che mudi sdng gan nha gan ngudi v.v

Qua qua trinh tham khao chiing tdi chua thay cd tai lieu nao ndi den diet mudi bang mbi ba diet mudi

IL3.4 Nhung cdng trinh nghien curu ve muoi va nhihig hda chat diet muoi chii yeu da dugc su dung d Quang Bmh

Quang Binh lam cdng tac sdt ret tir nam 1961 den nay Ngay tir iihirng nam dau Vien sdt ret - Ky sinh trimg - Cdn trimg Ha noi da c6 nhung dieu tra

ca ban ve mudi trong tong the chung cua mien Bic Cd the k l den mdt sd tac gia da cd nhimg nghien ciiu lien quan den mudi d Quang Binh: Vii Thi Phan,

Tran Diic Hinh, Nguyin Tho Viln, Pham Huy Tieii (1973), Nguyen Huu

Diic, Ho Van Huu (1973); Pham Huy Tien, Nguyin Diic Manh va cong su (1975); Vu Diic Huong va cdng sir (1990) [4, s, 9, 2i 63] Nghien ciiu theo ddi

su nhay cam cua mudi vdi cac loai thubc diet d Binh Tri Thien va xac dinii

thanh phan loai Anopheles va su phan bd theo cac viing canh quan (Ha Thi

Quyen va cdng su, 1986, 1994 [42.45]) Phan vien Sdt ret Quy Nhan cung da

cd nhiing ddng gdp quan trgng trong viec dieu tra xac dinh thanh phan loai

Anopheles a Quang Binh

Trong cdng tac phdng chdng sbt ret d Quang Binh hda chat chu yeii dugc diing de diet mudi la DDT, d dang long, dang bgt, ridng do tir 25% den 75% Theo sb lieu luu trii tai Tram Sbt ret Quang Binh tir nam 1961 den 1994 till binh qudn mdi nam Quang Binh phun DDT bao ve cho 150.000 den 200.000 ngudi trong viing sd't ret Sd lugng DDT dung cho mdi nam tir 20 ddii 50 tan Nhu vay trong thdi gian hon 30 nam qua, Quang Binh da sir dung khoang 900 tan DDT Nhiing nam gan day DDT dugc sir dung giam dan va hien nay DDT khdng cdn dugc sir dung niia [43]

Ngoai ra, mdt sb hda chat khac nhu 30+9, 666, Malathion, Sumithion ciing da dugc dimg de phdng chdng benh sbt xuat huyet nhUng sd lugng khdng nhieu lam Theo bao cao ciia Sd Y te Quang Binh (1994) thi nhiing nam giSn diy cac hda ch^ft diet mudi thudc nhdm PjTcthroid dang dugc dua vao ling dung thay the DDT Permethrin dugc diing tir 1992 dudi hmh thiic

tam man Binh quan mdi nam so man dugc tam khoang 30.000 c a i bao ve

cho 100.000 ngudi vdi khoang 200 - 300 lit Permethrin Deltamethrin dugc

dung tu 1993 dudi hinh thiic phun tbn luu Mdi nam bao ve khoang 100.000

ngudi Icon mdi dugc sir dung d mirc thap, cdn cd tinh chat thi diem

Tir nam 1991 chung loi c6 nghien cau mbi ba diet muoi Sau 3 nam tlii nghiem, mbi ba dia mu6i da dugc san xuat thir va ung dung tren m6t s6' dia

ban CO ket qua

PHAN III

THCJI GIAN, DIA DifiM VA PHUONG PHAP NGHlfiN CtfU

in.l MOT S6 DAC DI^M TlJ NFU^N VA KINH T^ - XA HOI 6 QUANG

BINH CO L I £ N Q U A N D ^ N SU PHAT TRifiN CUA Mu6l

I l l l l Dac diem dia Iv tir nhien

Theo Vu Tu lAp (1987) [26] va Uy ban khoa hgc ky thu^t nha nude

(1970) [58] ve khi hau va phan viing dia ly tu nhien lanh tho Vi^t Nam thi Quang Binh nam d vi tri:

Tir 16^45 den 18^05 Vi do Bac Tir 105*^34 den 106''58 Kinh do Ddng Phia Bac giap tinh Ha Tinli

Phfa Nam giap tinh Quang Tri Phia Tay la day niii Tmdng San, giap Lao Phia Ddng la bdBien Ddng

Dien tich toan tinh Quang Binh la 8750 km^, trong dd dien tich vimg niii dbi la 7.800 km", dbng bang 600 km va cat ven bien la 350 km^

Quang Binh cd chieu ngang nai hep nhat la 46,5 km, nai rdng nhat la

91 km Phia Ddng cd bd'Bien Ddng dai khoang 120 km, phia Tay la day niii

Tmdng San dai khoang 150 kin Quang Baih cd dac diim dia hinh phiic tap:

Viing nui phia Tay Quang Binh chiem khoang 2/5 dien tich toan tinh

B A N D 5 VIETNAM Hinh 1: vA KIIU Vl/C NGHIEN Cl?U

Dai bg phan la niii cd do cao tmng binh tir 600 - 700m Chi cd mdt sd nggn nui cao tr^n 1500m Dd ddc tmng binh tir 25° d6n 30" Cd nhirng day mii da vdi lien tiep phan chia vimg mii lay Bac Quang Binh dianh nhimg khu k'm

Cd nhfnig day nui keo dai an lan ra sal bien tao Uimih nhung viing ddi nui

<uap bien (Deo Ngang, Quang Ddng, Quang Trach)

Rimg Quang Binh (Thai Van Tnmg, 1978) [56] tliudc kieu rirng nhiet ddi xanh quanh nam vdi cac loai cay da dang va phong phii, cay gd cao, dudng kinh Idti, rirng nhieu tang Tham lliirc vat Quang Binh la mot trong nhung viing dac tnmg chiu tac ddng ciia con ngudi Trong nhung nam chife tranh tir 1965 - 1975 nhieu khu rirng bi bom Napan ddt chay, con ngudi dot pha rirng lam nuang rSy, khai Uiac ki^t rirng lam cho dien tich rirng giau ugay cJing tliu hep lai, nhuttng chd cho dang rinig ngheo, rimg thir sinh, trang

cd De khac phuc tinh Iraug dd, rirng trong cang dugc chu y Chi tinh rieng khu vuc dau ngudn thuoc hni vuc sdng Nhat I ^ cd deii 5.500 ha rimg dii va dang phat trien ( I B N D tinh Quang Binh 1994)

Tidp giap gifra vimg mii va vimg dbng bang la vimg gd ddi vdi di^n tich gan 2/5 dien tich ca tinh, cd do cao tmng binh tir 100 - 200 m, cd dd ddc ti:r 15*" - 20'\ Cung cd nhirng day cfdi thap chay dai ra sat bidn Tren dang dia hinh nay chii yeu phat trien nliung dang cay b u i thao mdc chi'^u cao ttr 0,5 -3m Mot sd dien tich bi khai pha de san xuat, mdt sd vimg trd thanh dbi Iroc, nhieu chd hi xdi mdn nghiem trong Day la klui vuc trgng didm duac quy hoach dua dan deii d, xay dung vimg kinh te m d i

Ddng bang hep, klidng phat trien dugc tlieo chieu ngang Mdt ben dugc gidi han bdi vung dbi mii, mdt ben la con cat, dun cai lau vao Vi vay,

dbng bang vdn da hep lai bi phan chia thanh nhifeu khu vuc nhd Clii cd (fdng bang I ^ Thiiy la tuang dbi Idn

Phia Ddng la mot mien cat bien cd do cao tir 5 - 2 0 m, chay dai sudt doc bd bien Nhuiig diiy cat nay cd tlie bien ddng do chiu anh liUcVng ciia gid miia Ddng Bac, Tay Nam va mrdc thiiy trieu Bat ngudn tir nhiing day cat cd nhimg khe sudi nhd, mrdc nggt, (]uanh nam chay vao dbng mdng Day la mdt

dac diem tuang ddi khac biet so vdi nhirng nai kliac

Nhin chung dia hinli Quang Binh klia phiic tap, mii dbi cao, dd ddc h'tii, dbng bang hep lai cd he tlidng sdng iigdi day dac phan cat Sir phan chia ranh gidi giiia cac viing dia ly tu nhi^n mii rirng, gd dbi, dbng bang va ven bi^n klidng rd rang, tham chi nhu la xen ke Can cir vao tliuc td' dia ly dd ma klii nghien ciiu tlianh pli^i loai va su ph4ii bd cua mudi d Quang Binli chiing tdi phan chia thanh cac viing canh quan nhu sau:

4 Viing nude chay mii rimg: Bao gbm nhimg viing nui cao, iiiii tmng bbili, rirng giau va nhieu tang

+ Viing nude cluiy niii cfdi: Bao gbm nhihig vimg nui tliap, gd d b i rimg ngheo, cay thafp nhd, trang cd

+ Vimg mii dbi giap bien: Bao gbm mii tliap, dbi giap bi^n

+ Viing dbng bling ven bien: Bao gbm dbng bang va vimg ven bien

III.L2 Dac diem klii hau

Theo PlKiin Nggc Toan va Plum T<i;i Dac (1978) [5ii, ht Ba Thao

(1977) [48]: Quang Binh chiu anh hudng khi hau nhi^t ddi gid miia, cd 2 miia

rd itt:

Miia khd keo dai tir tliang 3 den tliang 8, dinh cao la tliang 6 va tliang

7 Miia nay chiu anh hudng cua gid miia T<^yNani, khi hau khd, ndng, it mira, nhiet dd cao Tbc do gid tmng binh tir 2 - 4 m/s, cd khi l^n tdi 20 m/s

Miia mua keo dai tir thang 9 dfti tliang 2 nam sau, dinh cao la thang 10

va tliang I I Miia nay chiu aiili hudng ciia gid miia Ddng Bac, gky nen mua

nhieu, klil hau am, lanh Toe dd gid trung binh tir 2 - 4 m/s, cd khi tir 18 - 20 m/s Thdi ky chiiyen tiep giira hai miia khi hSu tliudng oi biic, g^y gidng td

va xuat hien bao lut

- Nhiet do tmng binh nam la 25''C

Nhiet dd tmng binh thang ndng nhEfl la 30'^C

Nhiet do tmng binh thang lanh nh;ft la 19"C

- Dd am tmng binh nam la 85%

- I ^ g n g mua binh qu^n ttr 2000 - 3000 rnm/nSm I-ugng mua ph^n bd'

klidng deu, tap tmng chii yeii vao cac thang miia mua Tir thang 9 diin thang

11 hrgng mua chiem 60 - 70% tdng lugng mua trong nam Cucmg dd mua manh

H e tlidng sdng ngdi day dac, cac sdng Idn bat ngudn tir day Tnrdlig San chay theo hudng Ddng Bac hoac Tay Nam ra bi^n Hfiu ha't cac sdng ngan, ddc, phan chia nhieu nhanh, dd ra bien nhanh Miia mua thucmg Irimg vdi miia bao Bao kem theo mua Idn, gSy ndn Iii lut d cac trien sdng, cubn trdi nh^k cua, hoa m^u, cac cdng trinh x;ly dung c a biin, tac du("mg giao thdng vSau klii mua, nude nit nhanh, mirc nude sdng trd nen can kiet Ve mua khd cac long khe khd can nude, lir(;ng mrdc d cac lid chiia giilm xudng nhanh, han han nghiem trgng Nude man xam nhap vao ha Imi cac sdng, lam cho dbng mdng bi nhiem man (Pham Nggc Toan va Phan Tat Dac, 1978)

I1L1.3 Tinh hinii kinh te xa hoi

Dan sb tinh Quang Binh cd 750.000 ngirdi, vdi 8 dau toe 1^ mot linh

cd nen kinh td'ndng nghiep la chii yeu, nam trong vimg klii hau kluic: ngliidt, thien tai nhieu, lai chiu dimg tnrc tibp g^n 10 nam chi6i tranh pha hoai cho ndn nen kinh tb Quang Binh cdn ngheo nan Theo bao cao cua UBND tinh (1994), Quiing Binh cd binh (|iiiin hrctng thuc d;iu ngudi dudi 200 kg; binh ()uan thu uhalp tir 100 - 120 ddla mdt nam Nhirng nam gan day, tir 1990 nen kinh tbdan dan dugc dn dinh, tdng san lugng nong, lam, ngu va cdng nghiep

cd tang so vdi tnrdc

Quang Binh cd tnic dutnig giao tlidng la dircmg sat va ducnig bd, xuyen sudt chieu dai cua tinh han 100 km Vao miia mua lii thudng xay ra ach tac giao thdng, de xay ra dich benh l l i i xa Dbng Hdi dang trong qua trinh dd tlii hda, mdi tnrdng cd nhieu thay dbi, la nai cd dibu kien thuan Igi cho cac loai mudi phat trien, dac biet la mudi sdt xuat huyet Mdt sd d ^ i tdc it ngudi cd difeu kien kinh te klid klian, phong tuc t^p quan lac h^u, nhieu dia phuang nam trong viing cd benh sdt ret luu hanh nang nhung nhan d ^ i khdng cd taip quiin ngu man Mdt bg [>han dan cu qua ngheo khdng cd m;m Mdt sb lugng kin nhan dSn d viing (fdng biuig vao rirng kliai tliac l ^ n san, da quy, di ve khdng on dinh Nhirng dieu nay da lam cho cdng tac phdng chdng sdl ret gap khdng it t r d n g a i

Toan tinh cd khoang 230.000 ngudi sbng trong viing cd bdnh sd't ret vdi sb ngirdi mac benh hang nam tir 10.000 den 20.000 ngucri; cd khoang 40.000 ngudi sdng trong vimg cd benh giun chi lim hanh vdi khoang 3.000 ngudi mac b^nh (Sd lieu Imi tru d Tram Sdt ret Quang Binh) Nhieu nam da

xiiy ra dich sbt xu^'t huyet vdi hang ngan bdnh nhAn bi mac (Lircrng Ninh

-1975, l.y N i n h - 1990)

HI 2 TIlOl GIAN VA DIA Dif'M NCin(:N CllH

Sd lieu dugc sir dung trong luan an nay la kel qua nghien cim tii nam

1975 dbn 1994 cd sir tnrc tibp tham gia ciia tac gia Ngoai ra chimg tdi tham khao tlieni sdlieu luu trir tai Tram Sdt ret Quiing Binh fir 1961 - 1974 va ket qua nghien cim ciia mot sd tac gia ve nhirng van d^ cd hen quan den ndi dung luan au

De nghien cuu thanh phan loai va su plian bd ciia mudi d (^uatig Binh

cluing tdi da dieu Ira a 31 diem Ireu Ur<\n tinh vdi 74 lan dieu tra (Bang 1)

Nghien cim thanh plian loai A/u>phch's va sir pluui bd, chimg tdi tlieu

tra 29 (hem v<ii 69 lan then tra thudc cac vimg siuh canh:

- Vimg nude cluiy mii rirng 14 diem 35 lAn dibu tra

- Vimg nirdc cluiy nui doi 10 diein 18 lan dibii tra

- Vung dbng bang ven bieni 4 diem, 11 lan dieu tra

- Vimg mii dbi giap bien 1 diem, 5 Tan dieu tra

Nghien cuu dac diem sinh hgc, sinh tliai hoc cua mdt sd loai mudi

(liucnig gap cd vai trd dich te quan trong nhu Aedes aegypti truyen sdt xuat huyet, Culex quinquefasciatus tmyen giun chi, Culex tritaeniorhynchus

tmyen viem nao Nhat Ban B, chimg tdi da diSu tra d 8 di^m thudc cac vimg:

- Viing thanh thi : 1 diem

- Vimg dbng bang ven bien : 3 diem

- Viing mii doi : 3 diem

Dia dicni va thdi giau dieu tra muoi d Quang binh

Din diem dien tin

Huyen - Xh

(2) Huyen Minh Hoa

3 - 1983 10- 1982

10 1983 10- 1992

Thi xa Dbne Hdi

Xi nghiep lien liiOp Dim

cong nghiep I-X)ng l.)ai

3 - 1975

4 - 1990

4 1994

8 - 1994 Tong sd

- Viing niii rimg : 1 diem

Mdi d\6n\ dugc dieu tra \\1 2 l^Sn trd len

Nghien cim mbi diet mudi dugc bat dau tir tliang 8 nam 1991 tai Quang Binh, deii tliang 8 nam 1992 cluing tdi dat dugc kei qua budc d^u ve di^Mi che' mdi diet m u d i Phan vien Sdt ret, Ky sinh triing, (]dn trimg Quy Nhon da tao dieu kien cho thir nghiem dugc tidu hanh tai phdng thi nghiem 'Hiang 2 nam 1993, Vien Sdt ret, Ky sinh trimg, Cdn trimg Ha ndi ky hgp (long nghien cuu Trong han mdt nam thuc hien tai Quang Binh, Ha ndi va 111(31 sd dia phuang khac, de tai da dugc nghiem tliu ph5n ngliien cum va ling dung mbi diet mudi tai Quang Binh vao thang 6 nam 1994

IIL3 PHl/ONG PHAP NGIIlftN ClJll

IIL3.1 Nghien ciru IIIIHH:

Dugc tic'n hanh theo cac thucrng (juy ky thuat thuc hanh ve ngliien ciiu mudi sdt ret va cac loai mudi kliac da dirge To chirc Y tc' the' gidi quy dinh (OMS, 1962 WHO, 1975) va nhimg ky thuat chuyen mdn trong cdng tac sdt ret cua Vidn Sbt ret, Ky sinh triing, Cdn trung Ha ndi (1971) (61.115, 116]

IIL3.1.1 Dieu tra miibi

- Dibu tra mudi ban ngay tir 7 gid ddn 11 gid bang each brit mudi dau tren cac dung cu, quan ao, chan man, viich ngan, tudng vach mat trong nha Soi bat mudi ngoai nha d cac hAni hd'e c<iy, bui cay, vach da

- Dieu tra mudi ban dem ttr 19 gid deii 23 gid d trong nha hoac ngoai nha bang each soi b^t mudi dau d cac dung cu trong nha mdi ngudi bat mudi Irong nha hoac ngoai nha va soi bat chubng gia sue Mbi ngudi sudt dem tir

19 deh 7 gid Srlng hdm sau va thu thAp mudi bang b<^y den

Mat dd mudi dugc tinh bang sd mudi bat dugc ciia mdt ngudi trong mdt gid theo cdng thirc:

Sd mudi bat dugc

MD =

Sd ngirdi biit x sd gid bat

Mat dd mudi dugc tinh tlieo nha

Sd mudi bat dugc

MD conAiha =

Sb nha dibu tra

C^i sd (%) nha cd mudi dugc tinh

Sd nlia cd mudi Chi sd nha cd mudi = x 100

Sd nha di^u tra

III.3.I.2 D i C u i r a b p g a y

Dieu tra bg gay d vimg ao hb, sdng sudi dam nude Ig, mirong mang,

cdng ranh, vung nude dgng Ddi vdi bg g^y Aedes aegypti tliudng dibu tra d

cac dung cu chiia nude nhan tao: b^^ nude an, be mrdc lam lanh klii nau nrgu,

be nude nha ve sinh Idp d td hdng, vd cfd hdp, gao dira, gdc cay dung nude, chailg vd

Mat do bg gaiy dugc tinh bang sd bg gAy bat dugc chia cho sd dung cu nhu gaOj bat, vgt

Vdi bg g^y Aedes aegypti thi tinh tlieo cac chi sb:

Breteau (tbng sd dung en cd bg gAy tren 100 nha dibu tra)

Container (ty le % dung cu cd bo gay tren tdng sb dung cu dibu tra) Premise (ty Id % nha cd bg gay tren so nha dieu tra)

ni.3.1.3, Xu ly va bao quan mau vaL

- Mudi trudng tlianli Uiu Uiap dugc bang cac phuang phap dieu tra dugc dinh loai tai chd va cam tieu ban bang kim thuy tinh giu trong dug nghiem day bang, cd bang phieii chdng mdc, hiit <4m dsiy b;uig mil bac, gan nen

- I3g gay sau khi thu tluip dugc dinh loai ngay hoac dua ve phdng thi nghiep nudi phat tridii thanh iiiudi dd lam tieu ban bd Bg g<1y dugc giir hlu dai bang each gan lieu ban len lam kinh va day bang cac phien kinh Cd tlie dimg nhieu loai dung dich gan khac nhan nhung chiing tdi tliudng sir dung

(lung dich pha theo cdng thirc ciia Vien Sdt ret, Ky sinh trimg va CCm tning

(1963) gdm: Hydral chloral 74 gam, Axit axetic 3 ml, Gdm Arabic 8 gam, mrdc cat 15 ml

111.3.1,4 Fhuotig phap xac djnli mudi

Chiing tdi tlieo he tlidng phan loai cua Stone, Knight (1959, 1977) va die bang dinh loai ciia Dodge (1962), Reid (1968), Stojanovich va Scott (1966), Dang Van Ngir (1962), Nguyen Thuctng Hien (1968), Vien vSdi ret,

Ky sinh trimg, Cdn trimg Ha ndi (1968, 1987)14,59,60.96,102]

III.3.2 Nghien cuu dilu die va umg dung mbi diet muoi:

Vdi muc dich la xac dinh mot phuang tliiirc sir dung hda ch^t diet mudi mdi an toan cho sire khde va nidi tnrdng, de ap dung, gdp p h ^ tang cudng cac bidn phap diet mudi truyen benh, chimg tdi da tie'n hanh nhiing budc sau:

1 Tham khao va he thdng hda cac bien phap diet chii yeu da dugc thuc hien tren die gidi va trong nude, nhirng hda chat da dugc dimg de diet mudi d Vict nam va Quang Binh

2 Thain kliao va nghien ciru dac tinh sinh ly, sinli tliai cua mudi, chu Irong den mdt sb loai cd vai trd dich te (juan trong

- Anopheles va cac loai mudi la tning gian tmybn sdt rel cini yeu