50 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KYSINH TRUNG S O I - 2 0 1 0
M O T SO DAC DIEM SINH THAI HOC CUA M u 6 l ANOPHELES EPIROTICUS 6 VUNG MCll MAN HOA
THUOC HUYEN CAN DirClC, TINH LONG AN
Le Xuan Hoi', Ho Dinh Trung ', Pham Diic Tung', Tran Thj Huyen', Ngo Van Hoang Ha CTV.
1: Vien Sdt ret - KST - CT TLT; 2: Trung tam y te' du phdng tinh Long An.
Tdm tdt
Bang cdc ky thudt thiCdng qui diiu tra, theo ddi cdc dgc diem sinh thdi hgc cila mudi, bg gdy cua WHO vd Vien Sdt ret - Ky sinh triing - Cdn triing Trung uang dd'i vdi lodi mudi An.epiroticus tgi 2 xd thugc huyen Cdn Dudc tinh Long An ttc ndm 2006 de'n 2008, chiing tdi cd mdt so nhdn xet sau:
MuSi Anopheles epiroticus d cd hai viing tdm- lua, viing nudi tdm nudc lg thugc huyin Cdn Dudc, tinh Long An Id lodi chii'm lai thi'so vdi thdnh phdn lodi Anopheles trong khu vice nghiin ciiu. Mudi cd ty li, mat do cao so vdi cdc lodi Anopheles khde, nhicng mat dd mudi, bg gay viing nudi tdm nudc lg cao gd'p hai ldn mat do vung tdm - liia.
MuSi cd tap tinh tru ddu, thicc hien chu ky tiiu sinh trong nhd (Endophillic) Id chu yeu: nai ddu thich hgiJ ciia miiSi Id vdch bdng Id dita nudc (Nimpa); dd cao nai mudi ddu trin tudng vdch tii 2,0 met trd xudng, nhiet do khdng khi giao ddng tic 24"C - 31"C; mudi thicdng ddu nai kin ddo, khdng bi dnh hudng cua gid, khdng cd dnh sdng chie'ii true tiip nhicng khdng qud dm icdt.
Bg gay Anopheles epiroticus sinh sdn vd phdt trien trong nudc lg, cd do man tic 1,0 - 3,5 gl lit; dd pH til 6,50 - 8,0: nhiet do nudc thay ddi tie 28 - 30''C; d bg gay cd dnh ndng chieu true tiip nhitng khdng qud chdi chang, trong nicdc cd thicc vdt thuy sinh (co hode rong) de che mdt ldm gidm nhiet do, ddng thdi la nai tni dn trdnh thiin dich ciia bg gdy
L D A T V A N D E :
Anopheles (Cellia) epiroticus Linton & Harbach, sp.n. Ia loai mdi dugc tach ra tii phiic hgp loai Sundaicus, ma trudc day cd ten la An. sundaicus la vec to SR chinh viing ddng bang nudc lg ven bien Nam Bd; dugc ghi.nhan cd mat d dat lien Cam pu chia, ban dao Malaixia, Thai Lan va Viet Nam.
Trong nhiing nam gan day, d cac tinh ddng bang ven bien Tay Nam Bd, cd nhieu su thay ddi ve mdi trudng, thay ddi phuong thiic canh tac, phuong thiic sir dung dat: nhu viec chuyen doi tii trdng Iiia sang nudi tdm, tir trdng riing sang ke't hgp nudi tdm nen da md rdng vimg phan bd, tang mat do mudi An. eproticus. Do vay, tinh hinh dich t l sdt ret trd nen khd kiem soat, dac biet la cac dia phuong cd dan di vao viing sdt ret luu hanh (SRLH) Ddng Nam Bd trd ve hoac dan tir cac viing SRLH nang den dia phuong cu trii. Tuy nhien, day chi la nhiing nhan xet ban dau, cd tinh chii quan va rdi rac. Vi vay viec nghien ciiu mdt so dac diem sinh thai, vai trd truyen benh SR ciia loai mudi An. epiroticus trong qua trinh man hoa d viing dong blng ven bien Nam Bd la cln thiet, nhlm gdp phan xac dinh vai trd truyen benh SR cua loai mudi nay, ddng thdi ddng gdp y kie'n cho viec lua chgn bien phap phdng chd'ng vec to thich hgp trong thdi gian tdi, vi loai mudi nay da khang vdi cac hoa chat thugc nhdm Pyrethroid da va dang su dung trong phdng chd'ng SR d Viet Nam. Vi vay, chiing tdi thuc hien de tai nghien eiiu "
Nghien cdu mgt sd dac diem sinh thdi cua mudi Anopheles epiroticus a vung mdi man hod thuoc huyen Cdn Dudc, tinh Long An" vdi cac muc tieu:
so 1-2010 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KYSINH TRUNG 51
+ xac dinh mat do mudi An.epiroticus b vung trdng tdm - liia va viing nudi tdm nudc lg.
+ Theo ddi anh hudng cua mdt sd ye'u td mdi trudng den cac dac diem sinh thai cua mudi, bg gay An.epiroticus.
-I- Xac dinh vai trd truyen benh sdt ret ciia mudi An.epiroticus.
2. DOI TUONG VA PHUONG PHAP NGHIEN CtJT:
2.1. Ddi tugng, thdi gian va Dia diem nghien cufu:
Loai mudi Anopheles epiroticus Linton & Harbach, nghien ciiu dugc tien hanh tai hai xa Long Huu Ddng va Long Huu Tay, huyen Cln Dudc, tinh Long An tit thang 5 nam 2006 de'n thang 12 nam 2008.
2.2. Phuang phap nghien ciru.
Nghien Ciiu dugc tien hanh theo cac phuong phap quan sat, md ta.
2.2.1. Chgn mlu nghien ciiu:
Diem nghien ciiu dugc chgn la:
-I- Viing tdm - Iiia: xa Long Huu Ddng, huyen Cln Dudc la viing trdng liia ke't hgp nudi tdm nudc Ig; miia mua thi nhan dan trdng liia, mua khd thi lly nudc lg nudi tdm. Day la xa thugc ddng blng ven bien nam giiia sdng Vam Cd Ddng, kenh Nudc Man va bien Ddng. La viing dugc chuyen ddi tir trdng liia sang nudi tdm nudc lg xen ke tit nam 1995 de'n nay.
-I- Viing nudi tdm nudc Ig: thugc xa Long Huu Tay, huyen Cln Dudc la viing dugc chuyen ddi phuong thiic canh tac tii trdng liia sang nudi tdm nudc lg tii nam 1995 de'n nay.
Diem nghien ciiu cd vi tri 10°029' 21,4" vi do Ble, 106 39' 58,8" kinh do Ddng.
2.2.2. Phuong phap xac dinh cac chi tieu nghien ciiu.
-I- cac dgt dieu tra tai thuc dia dugc tien hanh 2 lan/ nam: trudc va sau mua mua (cu the Iathang4, 5 v a l O , 11).
+ Phuong phap dieu tra thu thap mudi, bg gay theo ky thuat thudng quy ciia To chiic Y te The gidi (WHO), 1975; Vien Sdt ret- Ky sinh triing - Cdn triing Trung uong, 1971.
+ Phuang phap dinh loai mudi, bg gay da vao cac diu hieu hinh thai va theo Bang dinh loai Mudi, Bg gay, Quang Anopheles tai Viet Nam. Vien Sdt ret - Ky sinh triing - Cdn trung Triing Trung uong, 1987. [13]
-I- Phuang phap xac dinh vai trd truyen benh sdt ret ciia mudi dugc sir dung Ky thuat ELISA cua Robert A. Wirrtz et al, 1986,1987, 1992.
-I- Xac dinh miic nhay cam ciia mudi vdi hoa chat diet cdn triing bang quy trinh cua To chiiic Y te The gidi (WHO), 1998 (WHO/CDS/CPC/MAL/98.12).
2.3. Phuong phap xir ly sd lieu.
Sd lieu dugc phan tich va xix ly so sanh ti le theo X^ va so sanh trung binh theo t test diia tren phan mem thdng ke sinh hgc.
52 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG SO 1 - 2 0 1 0
3. KET QUA NGHIEN CtJU
3.1. Ket qua dieu tra mudi, bo gay vung torn - iiia va vung nuoi tdm nudc lg.
Bdng 1: Ket qud dieu tra mudi viing tdm - liia vd viing nudi lom nudc la Phuang phap dieu tra
Mdi ngudi TNdem
SL MD*
Mdi ngudi NNddm
SL MD*
Vung Tdm Iiia
2478 20,65 1854 15,45 Viing nudi tdm nudc Ig
3702 30,85 1956 16,30
Soi TN dem SL
126 318
MD*
1,06 5,30
BIy den TN SL
216 450
MD**
7,20 6,25
Soi TN ngay SL
378 1710
MD***
6,30 28,50
Chti thick: TN: trong nhd; NN: ngodi nhd; SL: sd lugng; MD: mat dp.
* Conlgi&l ngu&i; ** Conlbdyl dem; *** conlnhd.
Ke't qua d bang 1 cho thay: mudi An. epiroticus d viing tdm - liia cd tap tinh gin ngudi va dot mau ngudi cao. Ca 5 phuong phap dieu tra deu bit dugc mudi, trong dd phuang phap mdi ngudi trong nha dem (MNTN), mdi ngudi ngoai nha dem (MNNN) cd mat do cao ban ca, vdi mat do tuong iing la 20,65 con/ gid/ ngudi va 15,45 con/ gid/ ngudi.
Mudi An. epiroticus viing nudi tdm nudc lg cd mat do cao d tit ca 5 phuang phap dieu tra (bang 1). So sanh vdi viing tdm - Wa thi mat do mudi viing nudi tdm nudc lg cao ban gip 2 lln d tat ca cac phuong phap dieu tra; mat do dot ngudi trong nha ddm la 30,85 con/ gid/
ngudi, dot ngudi ngoai nha dem la 16,30 con/ gid / ngudi.
3.2. Ke't qua dieu tra mgt sd dac diem sinh thai hgc cua mudi, bg gay An epiroticus.
3.2.1. Dac diem sinh thdi cda mudi trudng thdnh.
3.2.1.1. Dac tinh noi trii dau cua mudi. (loai tudng vach).
Bdng 2: Ket qud dieu tra nai tru dn ciia mudi tren cdc lotxi tudng vdch khde nhau.
Dtr lieu
Sd lucfng Mat do (conI nhd) Ty le (%)
Cac loai tudng vach (chai lieu) Vach
la dira nudc 2016 11,20 50,98
Vach
288 1,60 7,28
Tudng gaeh
0 0 0
Ao qu^n
treo 468 2,60 11,83
Mai nha la dira nudc,
do cao
<l,5m 702 3,90 17,75
Cac dung cukhac
'(tu, bo...)
402 2,23 10,16
Vach c6 che bang vai nhua
78 0,43 1,97
Tdng cong
3954
Ke't qua bang 2 cho bie't quIn the mudi An. epiroticus viing nudi tdm nudc lg cd tap tfnh trii dau tieu mau trong nha (Endophyll). Cd 5/6 vi tri trong nha bit dugc mudi, trong dd vach la Dira nudc cd mat do cao nhlt (11,20 con/ nha), tie'p theo la nhiing noi cd mai nha blng la Dira nudc cd do cao dudi 1, 50 met (3,90 con/ nha), mudi cung thudng tni dau tren quan ao treo tren vach hoac gia treo (2,60 con/ nha).
s o 1-2010 TAP ru\ PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG 53
3.2.1.2. Do cao noi mudi dau so vdi mat dat.
Tie'n hanh thao ddi noi dau ban ngay ciia mudi loai nay theo 4 mtic do cao (tinh t^ mat da't trd len) khac nhau: tii 00 - 0,50 m, tir 0,50 - 1,00 m, tit 1,00 - 1,50m, tir 1,50 - 2,00m. Cac budc tie'n hanh dieu tra mudi dugc thuc hien tii 7 gid de'n 11 gid, sd mudi thu dugc dugc de theo do cao nhu da quy dinh.
Ke't qua cho tha'y do cao noi tni dau thuc hien chu ky tieu sinh ciia mudi tren tudng vach d diem nghien ciiu thay ddi tiir mat dit de'n 2,0 met, nhung d khoang each tii 0,50 m de'n 1,00 met chie'm ty le cao nhat (51,04% so vdi tdng sd ca the bit dugc d cac do cao), tiep de'n la do cao tir 1,00 de'n 1,50 met (ty le 38,62%), d do cao tii 1,50 -2,00 met chi chiem ty le 4,19%.
3.2.1.3. Theo doi iiliiet do, am do khdng klii noi tni dau ciia mudi.
Nhiet do °C Hinh 1: Phan bd sd lugng mudi theo nhiet do noi tni dau tren tudng
Ke't qua cho bie't nhiet do khdng khi noi dau ciia mudi An. epiroticus tren tudng vach thay ddi tii 24"C den 31°C, trong dd nhiet do cd sd lugng mudi cao nhlt la tii 28°C - 30°C (ty le mudi thay ddi tuong ling 19,69%, 24,52%, 25,23%). Dieu nay cho tha'y, mudi An.
epiroticus d khu vuc Tay Nam Bd ndi cbung va diem nghien ciiu ndi rieng thich nghi vdi dieu kien nhiet do cao phii hgp vdi khi hau nang ndng trong khu vuc.
3.2.2. Dde diem sinh thdi hgc cua bg gdy 3.2.2.1. Ke't qua dieu tra bg gay theo do man.
TyleBG(%) 35
0.1 0.5 1 1.5 2 2.5 3 3.5 Hinh 2: Phan bd ty le bg gay theo do man ciia nudc
4 4.5 5 Dp man (g/lit)
54 TAP c m PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG SO 1 - 2 0 1 0
Ke't qua hinh 2 cho thay bg gay An. epiroticus viing nudi tdm nudc lg khu virc nghien Ciiu phat trien trong nudc Ig cd do man thay doi tii 1,0 gr/Iit den 3,50 g/ lit, nhung cd ty le cao tir 2 g/lit den 3,50 gAit, cao nhlt d ndng do 2,50 g/lit (31,86% so vdi tdng sd cd thebg gay bdt dugc d cdc do man).
3.2.2.2. Ke't qua dieu tra bg gay theo do pH.
45 40 35 30 25 20 15 10 5 0
- ^ T y l e B G
A^
-* 1 • 1 <'- r-
5.5 6.5 .7.5 8.5 DopH
Hinh 3: Phan bd bg gay An. Epiroticus theo do pH
Ke't qua nghien ciiu hinh 3 cho thay, bg gay An. Epiroticus cd thi phat trien trong nudc cd do pH thay doi tii 6,5 den 8,0, nhung do pH thich hgp nhlt la 7,5 (ty 16 bg gay chie'm 41,81
% so vdi tdng sd ca the thu dugc d cac do pH khac nhau).
3.2.2.3. Ke't qua dieu tra bg gay theo miic do phan bd ciia thirc vat thuy sinh.
Trong 3 thuy viic cd bg gay loai nay phat trien thi vudng tdm nudc lg cd cd, rong cd ty le bg gay cao nhlt (51,39%), cd mat do 12,35 con/ vgt, tiep de'n la ao nudc lg luu thdng cd rong, ty le 31,21%, mat do 3,2 con/vgt.
3.3. Ke't qua xac dinh KSTSR trong mudi.
Bdng 3: Ket qud thd nghiem tim KSTSR trong muSi Sd lugng thii
Lan thii nha't Lln thii hai Lan thii ba Tdngcdng
Ke't qua So mudi thu
635 237 112 984
(+) 0 0 0 0
(-) 635 237 112 984
Nhan xet
Sd lieu bang 4 cho thay, thit nghiem 984 mlu mudi An. epiroticus bang ky thuat ELISA deu cho ke't qua am tinh.
4. BAN LUAN:
4.1. Phdn bd, mat do cua mudi, bg gdy An. epiroticus d viing tdm — Ida & nuoi tdm nudc Igf.
Ke't qua nghien ciiu ciia chiing tdi tai viing mdi man hoa thugc huyen Can Dudc, tinh Long An cho thay, quIn the mudi An. epiroticus d ca 2 md hinh tdm - Ilia, nudi tdm nudc lg
so 1 - 2010 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG 55
la loai uu the, chiem ty le > 80% tdng sd ca the thu dugc so vdi tdng sd ca the ciia 4 loai Anopheles. Tuy nhien, mat do mudi loai nay d viing nudi tdm nudc lg cao ban 2 Ian d viing tdm - Ilia. Nhan xet nay ciia chiing tdi cting nhu nhan xet ciia cac cdng trinh nghien cuu khac d viing cd dieu kien tuong tu. Sd di cd hien tugng tren II vi, viing tdm liia cd su thay doi ve do man ciia nudc, khi mua mua thi ngudi dan lai lly nudc nggt de trong liia, chi mua khd mdi din nudc lg de nudi tdm, cdn viing nudi tdm nudc lg thi thuy vuc nudc Ig dn dinh quanh nam.
Ke't qua nghien ciiu ve sinh thai hgc ciia loai mudi nay d ca hai md hinh nudi tdm cho tha'y, mudi An. epiroticus c6 tap tinh gin ngudi va dot ngudi cao. Ca 5 phuang phap dieu tra ve su lien quan ciia mudi vdi ngudi (hay khd ndng tiep xiic gida ngUdi - mudi) nhu mdi ngudi trong nha dem, mdi ngudi ngoai nha dem, soi trong nha ban dem, bly den trong nha dem va soi trong nha ban ngay deu bit dugc mudi, trong dd phuang phap mdi ngudi trong nha, ngoai nha deu cd mat do cao. Nhan xet ciia chiing tdi ciing phii hgp vdi nhan xet ciia mdt sd tac gia khac khi nghien ciiu d cac nudc trong khu vuc nhu Malaisia, d Nicoba (In Do). Khi nghien ciiu tinh ua vat chii ciia mudi loai nay tac gia Chow (1970) cd nhan xet mudi nay ua dot mau ngudi ca trong nha va ngoai nha [19].
Mudi An. epiroticus boat ddng ddt mdi sudt dem (tti 18 gid de'n 06 gid sang hdm sau), nhung cd dinh tii 20 gid de'n 2 - 3 gid sang, dinh cao nhat la 23 - 24 gid (mat do 22,32 con/
gid/ ngudi d trong nha va 15,66 con/gid/ngudi d ngoai nha). Ket qua nay ciing tuong tu cac cdng bd ciia cac cdng trinh trudc day d viing khac trong khu vuc, nhu d thi diem Phong Phii, Tp. Hd CM Minh (N.L. Giang & CS, 1980; N.T. Im & CS, 1992^ H D Trung & CS, 2002.
4.2. Nhan xet ve dac diem sinh thai hgc ciia muoT.
Ke't qua nghien ciiu budc diu ciia chiing tdi tai vung nudi tdm ket hgp trdng Iiia cho tha'y: boat ddng ddt ngudi cua An. epiroticus dien ra sudt dem d ca trong nha, ngoai nha, mat do cao tii 20 gid - 02 gid den 2-3 gid sang. Mudi bit dugc d tat ca cac phuang phap dieu tra, nhung mat do dot ngudi trong nha dem cao ban ngoai nha. Theo chiing tdi, sd di mat do cua loai An. epiroticus d viing tdm - Ilia tblp ban viing nudi tdm nudc Ig la vi cd su thay ddi do man ciia nudc, vi miia mua thi tren dien tich dd dugc trdng liia nen sft dung nudc nggt, chi miia khd ngudi dan mdi sir dung nudc lg de nudi tdm, cdn d viing nudi tdm nudc Ig cac thuy vuc tdn tai quanh nam (mac dii miia mua do man cd the giam th£p hon) nen bg gay ludn cd dieu kien phat trien.
- Ke't qua nghien ciiu noi tni dau thuc hien chu ky tieu sinh ciia mudi cho thly, vi tri thich hcfp nha't la vach la dira nudc (mat do 11,20 con/ nha), tiep theo la mai nha blng la diia nudc cd do cao dudi 1,50 met (mat do 3,90 con/ nha); ao quIn treo tren tudng vach (mat do 2,60 con. nha).
Ket qua nay ciing phii hgp vdi cac cdng trinh da cdng bd trudc day, do dd khi ap dung bien phap phun hoa chat tdn luu d viing nay chi can phun d do cao tur 2,0 met trd xudng.
- Nhiet do khdng khi nai mudi dau tren tudng vach thay ddi tii 24°C - 3l"C. Qua trinh dieu tra noi tni dau ciia mudi loli nay, chiing tdi thay: mudi thudng dau noi kin dao, khdng bi anh hudng ciia gid, anh sang chie'u trirc tie'p nhung khdng qui Im udt.
Mudi An. epiroticus viing nudi tdm nudc Ig xa Long Huu Tay, huyen Cln Dudc, tinh Long An da khang vdi 2 boa chit Alphacypermethrin vd lambdacyhalothrin thugc nhdm Pyrethroid da, dang sir diing trong phdng chd'ng sdt ret. Ke't qua thir nghiem cua chiing tdi cung phii hgp vdi ke't qua thii cua de tai INCO- DC nam 2003 tai xa Long Huu Ddng, huyen Can Dudc (ty le mudi che't 79,61% dd'i vdi Lambdacyhalothrin va 78,00% dd'i vdi Alphacypermethrin), xa Phudc Lai, huyen Cln Giudc (ty le mudi che't 77,64% dd'i vdi
56 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TPfrnft SO 1-2010
Lambdacyhalothrin va 92,10% dd'i vdi alphacypermethrin), tinh Long An va nhieu dia didm khac thugc mien Tay Nam Bd.
4.3. Vai trd truyen benh sdt ret ciia mudi d vung nghien ciiu.
Phan tich 984 mlu vat mudi khd de xac dinh KSTSR deu cho ke't qua am tinh (-), dieu dd phan anh diing thuc trang tmh hinh SR tai diem nghien ciiu. Theo sd lieu dieu tra tai Trung tam y te' huyen Cln Dudc trong 3 nam 2006, 2007, 2008 chi cd 05 trudng hgp benh nhan SRLS, dieu tra xet nghiem tren 6000 lam mau khdng phat hien dugc KSTSR. Tuy nhien, ke't qua dieu tra cho thay: mudi An. epiroticus vln giii vai trd vec ta truyen benh SR chinh d viing nay vi loai nay chie'm uu the' so vdi cac loai Anopheles khac; cd mat do dot ngudi cao. Tit ca nhiing cdng trinh nghien ciiu ve dich ti benh SR khu vuc ddng bang sdng Cim Long deu xac dinh mudi An. epiroticus la vec to truyen benh SR chinh viing nudc Ig ven bien Tay Nam Bg (Vu Thi Phan va CTV, 1980 [8]; Nguydn Long Giang va CTV, 1980; t r a n Diic Hinh va CTV, 1987; Nguyen Tang am va CTV, 1992. Le Dinh Cdng va CTV, 2001 khi nghidn ciiu bien phap phdng chdng sdt ret thich hgp cho viing nudi tdm nudc lg ven bien tinh Ca Mau da cd ke't luan, boat ddng nudi tdm, md rdng viing sinh thai nudc Ig cd lien quan den su Ian truyen SR, SR tang klii dien tich nudi tdm nudc Ig tang, vi qua trinh dd hinh thanh nhieu thuy vile thich hcfp cho bg gay loai mudi An. sundaicus phat trien. Hoat ddng nudi tdm ciia cdng ddng dan cu da lam gia tang sir tie'p xiic giiia ngudi va mudi, dac biet la nhiing ngudi trdng coi vudng tdm chi sir dung man khdng tam boa chat vi dan cho ring dung man tam boa chit se gay che't tdm (bdo cdo ket qua gidm sdt dich te SR tgi tinh Sdc Trdng ciia Vien Sdt ret - KST — CT Tp. Hd Chi Minh, 2002).
5. KETLUAN:
Tii nhirng ke't qua nghien ciiu tren, chiing tdi nit ra mdt sd ket luan sau:
1. Mudi Anopheles epiroticus d ca hai vung tdm- Ilia, vung nudi tdm nudc Ig thugc huyen Can Dudc, tinh Long An la loai chie'm uu the' so vdi thanh phln loai Anopheles trong khu vuc nghien ciiu. Mudi cd ty le, mat do cao so vdi cac loai Anopheles khac, nhung mat do mudi, bg gay vimg nudi tdm nudc lg cao gip hai lan mat do vung tdm - liia.
Mudi cd tap tinh tni dau, thuc hien chu ky tieu sinh trong nha (Endophillic) la chii ye'u; noi dau thich hgp ciia mudi la vach bang la dira nudc (Nimpa); do cao noi mudi dau tren tudng vach tir 2,0 met trd xudng, nhiet do khdng khi giao ddng tii 24°C - 31°C; mudi thudng dau noi kin dao, klidng bi anh hudng cua gid, khdng cd anh sang chieu true tiep nhung khdng qua Im udt.
2. Bg gay Anopheles epiroticus sinh san va phat trien trong nudc Ig, cd do man tii 1,0 - 3,5 g/ lit; do pH tii 6,50 - 8,0; nhiet do nudc thay ddi tii 28 - 30°C; d bg gay cd anh nlng chie'u true tiep nhung khdng qua chdi chang, trong nudc cd thuc vat thuy sinh (cd hoac rong) de che mat lam giam nhiet do, ddng thdi la noi tni In tranh thien dich ciia bg gay
KIEN NGHI
Tie'p tuc cd nhiing de tai tuong tu dugc tie'n hanh d viing khac cd dieu kien tuang tir dugc ap dung cac ky thuat cao nhu sir dung he thdng thdng tin dia ly (GIS) de cd the sir dung cac sd lieu CO ban dd xay dung he thdng dir bao ve phan bd, mat do, vai trd truyen benh SR ciia loai mudi nay dua vao nhiing thay ddi ciia tham thuc vat, phuong thiic sir dung da't canh tac, mdi trudng. Ddng thdi nghien ciiu viec danh gia hieu luc boa cha't diet cdn triing ddi vdi loai mudi nay. Dac biet la lam sao de bie't dugc viing phan bd cua An. epiroticus trong qua trinh thay ddi dieu kien mdi trudng do chuyen ddi phuong thiic sir dung da't nhu tiif trdng ltia sang nuoi tdm nudc lg, tir trdng riing sang nudi trdng thuy san nudc lg.
so 1 - 2010 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG 57
TAI LIEU THAM KHAO
1. Nguyen Tang a'm & CTV, 1991. Ye'u tdmdi sinh dnh hudng tdi sifphdt trien cila bg gdy An.sundaicus.
Ky yeu cong trinh nghien ciiu khoa hoc; Vien S6i ret - KST- CT, 1987: trang 259 -265.
2. Vu Dinli Chir, Pham Thi Hoan, Trinh Thi Kim Oanh {200S).Nghiin ci'di dgc diem sinh hgcvd xdy dicng quy trinh nudi Anopheles epiroticus trong phdng thi nghiem. Tap chi phong ch6'ng benh sot ret va cac benh ky sinh trUng. So 4- 2008: 46 - 57.
3. Nguyen Long Giang & CTV (1992). Yiu td mdi sinh dnh hudng di'n sic phdt trien cila bg gay An.
sundaicus. Ky ye'u c6ng trinh nghien cuu khoa hoc, Vien S6i ret -KST - CT, 1992; Tap I: 259 - 265.
4. Vu Thi Phan & CTV, 1980. Nhfcng dac diem cila binh Sdt ret d cdc tinh phia Nam. Ky ye'u c6ng trinh NCKH, Vien S6i ret- KST- CT, Nha xuai ban Y hoc, 1980: trang 5- 13.
5. H6 Dinh Trung va CIV. (2002). Hogt ddng tim mdi, tap tinh tru ddu ciia vec ta sdt ret tgi mdt so dia phicang dDong Nam d vd biin phdp phdng chdng vie ta thich hgp. Tap chi phong chdng benh s6i ret va cac benh ky sinh triing. Sd 3; 6 9 - 8 1 .
6. Vien Sdt ret - Ky sinh triing - Cdn triing Trung uong, 1987. 'Rang dinh logi Anopheles (miiSi, qiidng, bg gdy) d Viet Nam. 64 trang.
7. Chang Moh Seng, Linton Y M, & Harbach R. E. (2001). The Anopheles sundaicus species complex- a preliminaiy study of larval ecology from sites Sarawak, Malaysia. Mekong Malaria Forum 8: 91-95.
8. Dusfor, I, Linton, Y.M., Harbach R E, Baimai V, Trung H D & Maguine S. (2004b). Molecular evidence of speciation bePt\'een island and continental population of Anopheles (Cellia) sundaicus (Diptera:
Culicidae), a principle malaria vector taxon in Southeast Asia. Journal of Medican Entomology 41, 287-295.
9. Kumari R. & Sharma, VP. (1994). Resting and biting habits of Anopheles sundaicus in Car Nicobar Island. Indian Journal of Malariology, 30, 201-206.
10. Roop Kumari & V.P. Sharma (1994). Resting and biting habits of Anopheles sundaicus in Car Nicobar island. Indian Journal of Malariology Vol. 31, September 1994, pp. 103 - 114.
11. Stephen J. Connor, Medeleine, C. Thomson, Stephan Pflassse, 1998. Enviromental Information Systems in Malaria Risk Maping and Epidemic Forecasting. Disaster. 22 (1): 39- 56.
12. Uriel Litron, 1998. Landscape Ecology and Epidemiology of Vector- born Disease: Tools for Spatial Analysis. Journal Med. Entomology 35(4): 435-445.
13. Eveline Klinkenberg, Flemming Konradsen, Nathaly Herrel, Muhammad Mukhta, Wim van der Hoek, Felix P. Amerasinghe, 2004. Malaria vectors in the changing environment of the Southern Punjab, Pakistan.
Transation of the Royal Society of Tropical Med. Hyg. (2004) 98, 442 -449.
14. T Mariapan, N. Arunachalam, 1996. Brackish wate mosquito problem of Vypeen island. Cochin, Kerela Southeast Asian. J. Trop. Med. Pub. Health. Vol. 27; No. 1; March, 1996: 145- 148.
15. Yvonne Marie Linton, Dusfour I, Howard T. M., Ruiz L.F., N D Manh, Trung H D, Coosemans M., Harbach R. E. (2005). Anopheles (Cellia) epiroticus (Diptera: Culicidae) a new malaria vector species in the Southeast Asian sundaicus complex. Bulletin of entomological research. Vol. 95: 329-339.
58 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRUNG SO 1 - 2010
Abstract
SOME ECOLOGICAL CHARACTERISTICS OF ANOPHELES EPIROTICUS IN NEWLY SALINIZED ZONES OF CAN DUOC DISTRICT, LONG AN PROVINCE
Le Xuan Hoi', Ho Dinh Trung', Pham Due Tung', Tran Thi Huyen', Ngo Van Hoang^ et al
1. National Institute of Malariology, Parasitology & Entomology 2. Long An Provincial Center for Preventive Medicine
Ecological characteristics of larvae and adult mosquitos of An.epiroticus were investigated in two communes of Can Duoe district, Long An province using the routine techniques of WHO and NIMPE fi-om 2006 to 2008. Anopheles epiroticus was to be the dominating species of mosquitos in both shrimp-rice cultivation and the specialized shrimp farms. They were found with higher rate and density as compared to the other species in the
same area. The mosquito density in the specialized shrimp farms was double higher than that in the shrimp-rice cultivation areas.
An.epiroticus was found maily indoor resting. Their preferable resting places are on the wall made of water coconus leaves, frorn 2m high downward, with air temperature from 24"C to 31"C. They prefer resting in secret places, unwindy, undirectly sunshiny, but not too wet.
Larvae of An.epiroticus developed in brackish water with a salinity of 1.0 - 3.5grlliter;
pH: 6.5-8.0; water temperature 28-30"C. Larvae foci were found in sun shining places with aquaplants (grass or seaweed) which can shelter and frotect them from the Sun and natural enemies.
Can bd phan bi6n TS. Trinh Tirftng Vien Sdt ret KST-CT Tl/
so 1-2010 TAP CHI PHONG CHONG BENH SOT RET VA CAC BENH KY SINH TRONG 59
TILENHlfiM
AU TRUNG SAN DAI HEO (CYSTICERCUS CELLULOSAE) CAC YEU TO LIEN QUAN
Phan Anh TuSh, Trin Thi Kim Dung Trudng Dai hoc Y Duoe TP H6 Chi Minh
Tdm tdt
Muc tieu: Xdc dinh ti li nhiim an triing sdn ddi heo vd cdc yen to liin quan
Thiet ke'nghiin ci'cu: cat ngang. Diing thii nghiem ELISA dephdt hiin khdng the khdng dii tning sdn ddi heo.
Ket qud: Trong tdng sd702 mdu huyit thanh cua cdc binh nhdn dugc xet nghiem, cd 19 trudng hgp nhiem du tning sdn ddi heo,chii'm ti li 2,71%.
Ti le nhiim d nam 2,89% vd nit 2,44% (p>0,05); d tre em Id 1,09% vd ngitdi ldn 3,28% (p=0,118). Ti le nhiim d tinh, thdnh Id 1,59%; d nggai d, ndng thdn la 4,60% (p=0,017). Trong so cdc benh nhdn nhiim du triing sdn ddi heo, cd 89,57% dn ran sdng, 57,89% khdng nia tay trudc khi dn, 42,11% cd dn nem, 36,84% udng nudc khdng dun sdi, 36,84% chdn nudi heo, 5,26% tiin cdn cd binh sdn ddi.
Kit luan: Ti li nhiim du triing sdn ddi heo la 2,71%, Ti le nhiim khdng khde biit vi gidi. a nhdm binh ngudi ldn vd nhdm binh nhdn d nggai d, ndng thdn cd ti le nhiim cao hem. Cdc yeu tdldm gia tdng ti li nhiim du triing sdn ddi heo Id dn rau sdng vd chdn nudi heo.
L D A T V A N D ^
Theo nhan dinh ciia Xu L va cs benh ky sinh trung cd dien ngay cang giam nhung benh lay truyen qua thuc phim ngay cang tang trong dd cd benh au triing san dai heo (San day Ign) [13]. Benh lu triing san dai heo la van de quan trgng anh hudng ddi vdi siic khde cdng ddng, nha't la trong cac nudc dang phat trien. Benh phd bien d cac qudc gia chau a, chau Phi va cac Nam My [3], [8], [10] .
Tai Viet Nam, d mien Bic ti le nhiem lu triing sin dai heo la 5,3% [11], d mien Nam, trong cac benh nhan de'n kham tai cac benh vien, ti le nhiem la 3,8% [1]. Viet Nam cd nhieu ye'u td thuan lgi de benh au triing san dai heo phat trien nhu nhiet do, dd Im mdi trudng cao;
dieu kien ve sinh mdi trudng kem, xir ly chat thai ciia ngudi va vat nudi chua hcfp vd sinh, thdi quen an thiic an chua nau chin nhat la nhiing mdn cd ngudn goc tii thit heo nhu nem chua, tiet canh. Vi vay cbung tdi nghien cuu de tai: "Ti le nhiim au trung san dai heo va cac ye'u td lien quan" de cd dii lieu nhlm de ra cac bien phap phdng chd'ng cd hieu qua.
2. DOI TUONG VA PHUONG PHAP NGHIEN CtTU 2.1. Thiet ke nghien cufu: Nghien ciiu elt ngang
2.2. Co mkxx: duac tinh bdi cdng thiic: n=Z^p(l-p)/d^
Vdi do tin cay 99%, Z= 2,58 Do chinh xac tuyet dd'i d= 0,02 p=3,8%(2)
Co mlu la: 608
Chgn them 10% ma't mlu, ca mlu tdi thieu la 670.
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