56 Tap chi Nghien cilu va Phat trien, sd 5 (82) .2010
BO XIT HUT MAU - MOI QUAN TAM CUA CHUNG TA
Le Trong SoTn, Le The LUtfng*
1. Dat v a n de
Nhieu thang nay dU luan rat quan tam de'n loai bg xit hut mau xua't hien d nhieu tinh va thanh phd' d nUde ta. Do cd kha nang hut mau ngUdi, nen chung da lam cho nhieu ngUdi lo lang ve vai trd truyen benh dd'i vdi con ngudi.
Loai bg xit hiit mau nay thude hg Reduviidae (Latreille, 1807). Hg Reduviidae (tif nghia ehU Latin: reduvius la vet x\i6c, dau vet), dugc ggi la bg xit an thit hay bg xit am sat, cd tdi 7.000 loai, phan bd' rdng tren the gidi.
Hau het cac loai thuge hg Reduviidae cd tap tinh bat mdi an thit, tieu diet cac loai gay hai cho cay trdng nhU cdn trung, nhen... Vi vay chung la thien dieh quan trgng tren ddng rugng, vUdn cay va duge xem la cdn triing cd ich.
Ngoai ra cd mot so' it loai trong hg Reduviidae ed the tan cdng hut mau gia sue, gia cam, thu hoang va ngUdi. Mot so loai edn ed kha nang truyen benh trung roi ky sinh dudng mau eho ngUdi va gia sue.
Trong bai bao nay, chung tdi eung cap mot sd' thdng tin can thiet vdi mong mud'n ban dgc hieu them ve loai bg xit hut mau dang la mdi quan tam chung eua chung ta.
2. Dae diem n h a n dang va p h a n loai
Cac dae diem quan trgng de nhan dang cac loai thude hg Reduviidae:
Co kich thudc trung binh (tif 4-40mm), dau hep va keo dai, phan dau nam phia sau mat kep duge ggi la cd. Mat kep rat phat trien, phia sau mat kep cd 2-3 mat don. Rau hinh sgi, ed 4 hay 5 ddt. Phia trudc dau cd mot vdi eong dai 3 dot ra't dd tha'y, voi xep vifa van vdi mot r a n h euia mat bung dot ngifc trUde, cuf dgng eua vdi cd the phat ra tieng dgng, dd la each de chung de dga eon moi. Canh ed 2 phan la phan cufng d gd'c nhd va phan mang d nggn ldn hon vdi 2 hay 3 o canh. Chan dai, ed gai hay long, mot sd loai chan trUdc ed cau tao kieu bat mdi. Bung thudng phinh rdng ra d giufa va 1dm dgc theo than, mep cac dd't bung thudng Id rd ra dUdi canh, cdn goi la diem bung.
( H i n h l ) .
Reduviidae la mot hg rat da dang ve hinh thai, mau sac va noi sinh sdng. Phan hg Triatominae (thuge big Reduviidae) cd 14 gid'ng vdi 130 loai (Rose, 2003), nhifng ehi ed 3 gid'ng la Triatoma, Rhodnius va Panstrongylus ed vai trd truyen benh, trong dd quan trgng nha't la gid'ng Triatoma. Gid'ng Triatoma cd 70 loai, nhung cd tdi 42 loai mang ky sinh trung Trypanosoma cruzi gay benh Chagas (Sandoval et al. 2000, 2004). De'n nay da xae dinh dugc 5 loai la vector quan trgng eua benh Chagas: 1) Triatoma infestans;
* Trudng Dai hpc Khoa hpc Hue.
2) Rhodnius prolixus; 3) Triatoma dimidiata; 4) Triatoma brasiliensis va 5) Panstrongylus megistus. Ngoai ra mot so' loai khae ciing lien quan de'n viec truyen benh nhifng tuy theo khu vUe dia ly: Loai Reduvius personatus, Triatoma sanguisuga, Tratoma rubrovaria, Triatgma uhleri... phan bd' d Nam My; Loai Triatoma rubrofasciata phan bd' d An Do va khu vife chau A.
Vay loai bg xit hut mau xuat hien d nUde ta da duge eac phuong tien thdng tin de cap gan day thude ve loai nao?
0 Viet Nam, loai bg xit nay chUa dugc nghien cufu mot each day du ve hinh thai phan loai, dae diem sinh hge, sinh thai hge va nha't la vai trd truyen benh euia chung. Ket qua dieu tra eo ban ve cdn trimg nam 1967- 1968 d mien Bae Viet Nam eua Vien Bao ve ThUe vat cdng bd' da phat hien cd 75 loai thudc hg Reduviidae, tuy nhien khdng cd loai nao thudc 3 gid'ng cd vai trd truyen benh neu tren. Nghien cufu gan day eua eac nha khoa hge ve ho Reduviidae d mien Bac va mien Trung Viet Nam nhu Le Xuan Hue (2005, 2008, 2009); Dang Dufc Khuong (2007, 2008, 2009), TrUUng Xuan Lam va nnk (2007); Cao Thi Quynh Nga va nnk (2009)... da ghi nhan dugc khoang 100 loai bg xit thuge hg Reduviidae d nUde ta, tuy nhien cung khdng ed tac gia nao de cap de'n loai bg xit hiit mau nay.
O Thifa Thien Hue, ket qua dieu tra ve hg Reduviidae (tif 2001 de'n 2004) cua chung tdi da phat hien dugc 12 loai thuge 8 gid'ng, tuy nhien trong danh sach loai cdng bd v i n khdng cd loai nao thude 3 gid'ng Triatoma, Rhodnius va Panstrongylus.
Trudc tinh hinh bg xit hut mau xuat hien nhieu d cac dia phUOng trong tinh, Trung tam Phdng chd'ng Sdt ret-Ky sinh triing-Cdn trimg Thifa Thien Hue da dieu tra ve dieh te hge, cdn triing hge va thu duge 36 con bg xit eung mot loai. Theo bae si Nguyen Vd Hinh, Giam dd'e Trung tam, cho biet de'n cud'i thang 9/2010 da ed tdi 14 phudng xa cd bg xit thudc loai nay xuat hien va ed 5 ngUdi bi bg xit dot nhUng ehUa tha'y benh nhan nao cd bieu hien cua benh Chagas d Thifa Thien Hue. NhU vay cd the tha'y bg xit da xuat hien d Thifa Thien Hue tren dien rdng nhUng mat do khdng eao va chua tao thanh
"d" ldn nhu d eac dia phuong khae.
Tif eac ket qua dieu tra thu duge d Hue (hinh 2) va nhieu dia phuong khae, chung ta can lUu y cac dae diem hinh thai chinh cua loai bg xit hut mau nay nhu sau.
Bg xit trudng thanh cd hinh d van dai, dep va dai khoang 16-19mm.
Mau sac ecf the nau tdi, ed mot so vung hep mau hdng nhat. Phan dau hoi keo dai; rau manh 4 dd't; phu mieng kieu chich hut tao thanh vdi nhifng khdng eong d gd'c nhU eac loai khae trong hg Reduviidae. Manh lUng ngifc trUde hinh thang, be mat cua manh lung ngifc trUdc khdng bang phang. Tam giac canh eung khdng phang, mau nau den. Phan cufng eua canh trUde cd 2 vet hdng, 1 vet d gd'c canh dai hep va xep dgc, 1 vet d gan noi tiep giap vdi phan mang eua canh rdng hon, hinh tam giac. Khi dau canh xep Igt vao trong, de Id ra mat lung cua phan bung (diem bung), tren dd ed 5 dudng sge mau hong. Tha'y
58 Tap chi Nghien cilu va Phat trien, sd 5 (82). 2010
rd mot dudng vien mau hdng kha rdng bao ngoai diem bung. 0 con due diem bung thudng be to hon va hoi venh len phia tren so vdi eon cai.
Chung tdi cijng ddng y vdi cac chuyen gia eua Vien Sinh thai va Tai nguyen Sinh vat va Vien Sdt ret-Ky sinh trung-Cdn trung la bg xit hut mau dang duge ndi de'n thuge ve loai Triatoma rubrofasciata De Geer, 1773. Day la loai bg xit phan bd rdng tren the gidi, hut mau gia sue, gia cam, thu hoang va ngudi. Theo E. O. Essig, loai Triatoma rubrofasciata De Geer cd the la vat trung gian truyen trung roi ky sinh dudng mau gay benh "Kala-ar" (benh
"hac nhiet") eho ngUdi d An Do. Tuy nhien cho de'n nay ehUa cd tai lieu nao khang dinh loai nay la mdi gidi truyen benh eho ngUdi d Viet Nam.
3. Mot so dae diem sinh h o c va vai tro t r u y e n b e n h c u a loai bo xit hiit m a u
Cac loai bg xit hut mau ed bie'n thai khdng hoan toan, vdng ddi trai qua 3 pha phat trien la trufng, thieu trimg va trUdng t h a n h (hinh 3). Trufng hinh d van, mau hoi vang, de tifng qua nam rdi rac tren gia the, sau 2-5 tuan trufng nd thanh thieu trdng (nympha). Thieu trung cd hinh dang gid'ng vdi trudng thanh nhUng kich thUde nhd hun va khdng cd canh, bd nhanh. Sau 4 lan lot xae, thieu trimg phat trien thanh trudng t h a n h (imago) cd day du canh, kich thUdc dat de'n 20mm. Vdng ddi tif trufng den trUdng thanh thudng la 1 nam. Con due va con cai sai khae nhau ve sU phat trien ciia diem bung, con eai de trufng ngay sau khi giao phd'i.
Trudng thanh ciia cae loai bg xit thude gid'ng Triatoma thudng sdng trong khe da, ke tudng nha, mai nha tranh, ed the bd tren da't, eat hay tren la cay... d cae vimg ddi, nui hay vdng ddng bang. Ket qua dieu tra eho tha'y chung ed the tap trung nhieu ca the vao mot dia diem - ggi la "d bg xit", sd lugng tdi hon mot n g a n e a the. Theo Tien si TrUUng Xuan Lam, noi bg xit tap trung nhieu thudng lien quan de'n dieu kien am thap, ed eac gia the nhu dong cui, gd muc, gan vdi cd'ng, ranh la ncfi cd nhieu chugt sinh sdng...
tao dieu kien thuan lgi cho bg xit hut mau d l dang tru an va sinh san. Mot dieu dang luu y la bg xit ed the tru dau d tren tudng, eac hd'c 1dm, noi difng dd vat, dudi gam giudng... trong nha va chung cd the bay rat nhe nhang tif noi tru an de'n dau tren ecf the ngUdi de hut mau (vi the chung dUcfc goi la
"ke am sat") (hinh 4).
Kha nang hut mau cua cae loai bg xit thuge gid'ng Triatoma da dugc nhieu cdng trinh de cap de'n. Ca con cai, con dUc va thie'u trung deu hiit mau, thudng hut vao ban dem va hut mau nhieu lan. Vet dd't thudng khdng ldn, tao thanh mot viing dd ta'y va gay ngufa. Do gay ngufa nen ngudi bi dd't thudng gai, lam eho vimg da quanh vet dd't bi thuong tdn. Mot cau hdi dugc dat ra la cac loai Triatoma ed thufe sU ehi hut mau ngUdi h a y k h d n g ? Theo nhieu nghien cufu thi cac loai bg xit hut mau nay thUe sU khdng cd tap tinh lUa chgn vat ehu (con mdi) va khdng cd tap tinh Ua hut mau ngudi. Khi xet nghiem lugng mau ma chung da hut thi cae nha nghien cufu cua nudc ta da khang dinh phan ldn chung hut mau chugt hay cac ddng vat khae nhu gia
cam, gia sue. De'n nay v l n ehUa cd tai lieu nao khang dinh loai bg xit ma chung ta dang quan tam de'n lai cd tap tinh Ua hut mau ngUdi, viec hut mau ngudi dugc xem la sif nglu nhien. Cac cdng trinh khoa hge da ehi rd cac loai bg xit thudc gid'ng Triatoma cd the hut mau tdi 150 loai ddng vat cd xUUng sdng nhu chim (hinh 5), thu va ngUdi. Chinh vi vay, cum tif thUdng dimg bay lau nay tren cac phuung tien thdng tin dai chung la "bg xit hut mau ngtfcfi"
la khdng that dung, ma chi nen dung cum tif "bo x i t h i i t m a u " la du, neu khdng se gay hoang mang lo sg cho ngUdi dan.
Vai trd va eo che truyen benh cua cac loai bg xit hut mau nhu sau: Ky sinh trdng gay benh do eac loai Triatoma truyen sang vat chii khae gdm nhieu loai khae nhau thuge eac gid'ng trdng roi dUdng mau Trypanosoma va Leishmania. Sau khi hut mau vat chii, bg xit bai tiet chat thai (phan) ngay ben canh vet dot, phan ed mang mam benh la eac trung roi dUdng mau.
Vet dot gay ngufa nen ngUdi ta thudng gai, do gai nen gay thuung tdn vung da bi dot, mam benh tif phan bg xit ed mang mam benh se xam nhap vao vet xUdc, vLing thuung tdn tren da de vao mau ngudi. Vdng ddi cua ky sinh triing gay benh nay phat trien ea trong cu the bg xit va ea trong eU the vat chu. Trong co the vat chii (ngUdi hay ddng vat cd xUUng sdng khae), ky sinh triing tiep tuc phat trien hinh thanh cae the vdi hinh dang khae nhau nhU Trypomastigote va Amastigote. The Trypomastigote cd hinh thoi, hoi gid'ng ludi liem, ed mot nhan va mot roi xep dgc ve phia sau cof the tao thanh mot mang ud'n de thieh nghi vdi sU van chuyen trong mau la mdi trUdng cd do nhdt cao. Sau mot thdi gian di chuyen trong mau cua vat chu, the Trypomastigote de'n dinh khu d cac thd eo hay cac te bao eua tuyen giap, chuyen thanh the Amastigote. The Amastigote cd hinh trufng, cd mot nhan va mot roi d phia trUdc. Sau dd the Amastigote vao eo the bg xit chuyen thanh the Epimastigote cd cau tao tuong tU nhU the Trypomastigote. Trong CO the bg xit the Epimastigote lai chuyen thanh the Trypomastigote xam nhap vao co the vat ehu tif eac vet dd't (hinh 6). Su lay n h i l m eua ky sinh trimg gay benh tif bg xit vao ngUdi ed the la do vet dot hay lay lan tijf phan bg xit vao vimg da bi thuong tdn, vi vay chung ta can lufu y rang khi bi bg xit dot thi ed gang difng gai nhieu, tranh thuong tdn cho da va h a n che duge sU xam nhap eua ky sinh trimg gay benh tif phan bg xit.
Gid'ng trimg roi ky sinh dUdng mau (hay ky sinh ndi tang) Trypanosoma gay benh d ngUdi gdm mot so' loai, cd vimg phan bd va truyen cae ngudn benh khae nhau: O chau Phi cd 2 loai la Trypanosoma rhodesiense va Trypanosoma gambiense, gay benh ngu "li bi", vat trung gian truyen benh la rudi Txe-txe (ed ten khoa hge la Glossina palpilis). Phan bd d chau My cd 2 loai la Trypanosoma cruzi va Trypanosoma triatomae gay benh Chagas d Nam My va Trung My. 6 nUdc ta va mot sd nUde d chau A ed loai Trypanosoma evansi gay ra eac chufng benh nhU say thai, gay yeu, suy giam m i i n dieh... tren vat nudi nhu trau, bd.
Benh Chagas duge nha khoa hge ngudi Brazil Carlos Chagas phat hien vao nam 1909, de'n nay da tha'y xuat hien tren 18 qud'e gia, chu yeu la
60 ' Tap chi Nghien ciiu va Phat trien, sd 5 (82) .2010
d Trung My va Nam My. Hien nay cd khoang 10 trieu ngUdi tren the gidi mac benh nay. Cac loai bg xit hiit mau (thuge 3 gid'ng Rhodnius, Triatoma, Panstrongylus) da truyen ky sinh trimg Trypanosoma cruzi vao eO the ngUdi qua cac vet dd't hoac vet xUdc do ngufa gai tai eho do bg xit dd't. Benh eung cd the gay nen do truyen mau, do tai nan nghe nghiep trong phdng thi nghiem, nhidm qua sUa me hoac qua eac manh ghep tang, te bao... cd mang mam benh. Tat ea mgi lufa tuoi deu la ngudi cam thu va ed the bi mac benh.
Ngoai ra benh cd the lay qua dUdng thife pham. Nam 1991, nhieu ngudi dan d bang Paraiba, Brazil, bi nhiem do ud'ng nude ep h a t eg acais (thude hg Co Areeacea) va nUdc mia ep ed chufa ky sinh trimg. Mot vu dieh nam 2007 gay benh eho 103 tre em d mot trUdng hge Venezuela do dung nUde ep qua di bi nhilm loai ky sinh trimg nay.
Benh Chagas cd 2 giai doan la cap tinh va man tinh. Dd'i vdi giai doan cap tinh, benh Chagas ed thdi gian u benh tif 1-2 tuan tif khi bi bg xit dot va keo dai khoang 2 thang. Khi hi bg xit dot, ky sinh triing se xam nhap qua da, tai chd bi ky sinh.ti'Ling xam nhap se xuat hien cue cufng dd sam va hdng ban kem theo sufng dau. Neu ky sinh trimg xam nhap qua niem m§c mat, cd dau hieu Romana (mot dau hieu kinh dien cua benh Chagas cap bao gom sUng mi mat d phia ben cua khudn mat gan vet thuong can hoac vd tinh eg xat vao mat, ngudi benh se bi phii ne mot ben mi mat va quanh hoc mat), dau hieu nay ed the tdn tai khoang 2 thang. Ngudi bi ky sinh trimg xam nhap se tha'y met mdi, budn ngii va sdt eao.
Ddi vdi giai doan man tinh, benh ed the keo dai nhieu nam. Bieu hien lam sang thudng gap d tim, nao, thifc quan va phdi: Thife quan thudng bi gian to, dau; benh nhan cam tha'y dau ngUc, khd nud't va ndn. Hay gap trieu chufng khd thd khi hit vao, dae biet la trong khi ngu.
Mot cau hdi khae duge dat ra la d Viet Nam cd xuat hien benh Chagas hay khdng? Chung tdi hoan toan nha't tri vdi cae nha khoa hge chuyen nganh da khang dinh rang benh Chagas chUa thdy xuat hien d nUdc ta.
Benh nay ehi phan bd d Nam My (hinh 7), gan day benh ed pham vi lan rdng hon sang mot sd nude d chau Au (Bd Dao Nha, Tay Ban Nha va chau A (Nhat Ban) tuy nhien ty le ngUdi mac benh khdng dang ke. Benh Chagas chi lay nhilm trong cdng dong dan cU khi cd cac dieu kien sau day:
- Thuf nhat la phai ed nguon benh, la loai trdng roi dUdng mau Trypanosoma cruzi. Theo cdng bd eua eac nha khoa hge nUde ta thi cac loai triing roi ky sinh d cae dgng vat ed xUOng sdng va ngUdi edn ehUa dugc xae dinh rd cd loai Trypanosoma cruzi hay khdng, cdn d ngUdi benh ed nghi la do ky sinh trimg gay ra thi v I n chUa phat hien tha'y loai trimg roi nay. Ket qua nghien eufu gan day eua Thae si Nguyin Thi Giang Thanh, bd mdn Ky sinh trung, Vien Thu y eho tha'y da phat hien cd ky sinh trimg Trypanosoma trong CO the bg xit, tuy nhien cijng chUa khang dinh loai trimg roi nay cd phai la Trypanosoma cruzi la loai gay benh Chagas hay khdng.
- Thuf hai la can phai cd vat truyen benh, la cae loai bg xit hut mau thuge 5 loai va 3 gid'ng da ndi d tren. Mac dii cac nha khoa hge da xae dinh
dugc loai bg xit hut mau xua't hien d nhieu dia phuong cua nUdc ta gan day thude gid'ng Triatoma, tuy nhien lai khdng phai la cae loai truyen benh chinh da duge xae dinh, ma la mot loai khae cd lien quan de'n benh triing roi dudng mau khae chuf khdng phai benh Chagas d chau My dang lam mgi ngudi lo lang.
- Thuf ba la de benh lay lan nhanh trong edng ddng thi mat do loai bg xit phai cao va bg xit phai cd tap tinh Ua thieh hut mau ngUdi. Qua dieu tra phat hien thi ngoai trif d thanh phd Ha Ndi cd 2 d bg xit cd so lUUng ca the ldn (tif 200 ca the de'n hon 1000 ea the), cdn lai loai bg xit nay chi xua't hien rai rac d mot so diem. Vi du d thanh phd Hue, loai nay bat dugc d phUdng Vinh Ninh, Tay Lgc vdi mat do rat thap. Khi xet nghiem mau trong cU the bg xit, cae nha khoa hge nUde ta da khang dinh phan ldn la mau chugt hay cae dgng vat khae. Nhu vay tap tinh Ua hut mau ngudi eua bg xit vSn ehUa khang dinh.
Mat khae dien bie'n benh d nhUng ngUdi bi bg xit dot vifa qua cho tha'y:
Vet dd't do bg xit ed hien tugng dau, ngufa, sUng tay lan rdng xung quanh.
Sau 3-5 ngay, mot so' vet thuong cd the tu lanh, mot sd' vet dd't cdn thSm mau, nhifng chua ed ngUdi nao ed bieu hien sdt, budn ngu hoac bieu hien eua benh Chagas. Tuy vay khdng loai trif kha nang bg xit hut mau dang xua't hien cd the truyen mot so benh trung roi dUdng mau khae. Vi du d An Do, Joshi, va cdng sif da cdng bd suf xua't hien thich ufng ciia loai Trypanosoma evansi tren ngUdi va cd kha nang gay benh cho ngUdi.
4. P h o n g cac b e n h do bo xit hut m a u t r u y e n b e n h 4.1. Chan dodn
Chan doan benh do trimg roi ky sinh dUdng mau gay ra:
- Phat hien the Trypomastigote trong mau d giai doan sdt cap tinh:
Lam tieu ban mau dan gigt dae rdi nhugm giemsa.
- Xet nghiem sinh thiet laeh, gan, hach bach huyet trong giai doan man tinh hay benh nhan tuf vong.
- Cac test huyet thanh hoc: Miin dieh huynh quang, m i i n dieh phdng x a v a E L I S A .
- Nudi cay ky sinh triing tren mdi trUdng nhan tao.
- Phuong phap chan doan cdn trung: Lay mau benh nhan gay nhiem cho gian, sau 10 ngay lay nhilm se xua't hien ky sinh triing trong phan gian.
4.2. Phdng chdng benh
Phdng, chd'ng benh bang each phat hien va dieu tri benh nhan, chd'ng bg xit hut mau bang nhieu phuong phap nhu eai tao dieu kien sdng, ve sinh canh quan mdi trudng, pha huy noi cU tru va sinh san ciia bg xit. Van dgng ngudi dan thudng xuyen kiem tra lai tat ca dd dae lifu giuf lau ngay d nhdng ncfi kin dao, soi den de phat hien bg xit hut mau (tat het bdng den dien, dung den pin soi vao eac khe hd ban ghe, nan giudng, vach tUdng, hoc 1dm...), khi phat hien tha'y thi diing kep de bat, dung diii tre, gd giet chet.
62 Tap chi Nghien cilu va Phat triln, sd 5 (82). 2010
Neu phat hien tha'y d cd sd lugng nhieu ea the bo xit thi cd the dung cac hda chat dimg trong y te, nhU Permethrin 50EC, Fendona lOSC, ICON 10 WP (nhdm cd ngudn gde tif thifc vat - pyrethroid), lieu 30mg hoat cha't/m^ phun true tiep vao d, sau dd phun trong va xung quanh nha gid'ng nhu phun diet mudi. Tuy nhien, chung ta nen can trgng trong viec dimg hda chat vi nd se anh hudng de'n sufe khoe eua mgi ngUdi va trong nhieu trUdng hgp thi suf dung bien phap thu edng de tim va diet bg xit nhu tren la ra't hieu qua. Ben canh dd can hieu rd con dUdng lay nhiem ky sinh trimg tif bg xit vao ngUdi chu yeu tif phan bg xit qua vet gai xUde va vet ddt, do dd can h a n che gai va lam ve sinh xung quanh vet dot (hinh 8).
Hien tai ehua cd vac xin chd'ng benh Chagas va cae benh do trimg roi dudng mau gay ra. Mot so vac xin tiem nang hien dang duge thuf nghiem.
Hien cd rat nhieu loai thud'e de dieu tri benh Chagas nhifng khdng phai cd hieu qua nhU nhau, do dd ngUdi ta khuyen cao dimg mot so' loai thud'e dae hieu. Khi bi benh Chagas dimg Nufurtimox lieu lOmg/kg co the/
ngay cho hgUdi ldn va 15mg/kg eU the/ngay eho tre em, chia 3 lan, ud'ng trong 60 ngay, 90 ngay hay 120 ngay tiiy thudc vao sufe chiu difng eua eo the.
Cd the ed mot so bie'n ehufng phu khi dimg thud'e.
Cung ed the dung Benznidazol lieu 5mg/kg co the/ngay vdi ngUdi ldn va lOmg/kg eo the/ngay vdi tre em, chia 2 lan, ud'ng trong 60 ngay. Hai loai thud'e nay cd tac dung tieu diet cae ky sinh trung gay benh trong md va trong mau cua ngUdi mang ky sinh trimg. Nhifng ca 2 loai thud'e nay deu khdng cd kha nang loai tri^ hoan toan ky sinh trimg khdi co the, dae biet d nhiJng benh nhan bi nhiem man tinh va da khang thud'e. Cae nghien cufu cung cho tha'y viec dieu tri chd'ng ky sinh trung se chUa tri duge khoang 6()-85% d ngudi trudng thanh va tren 90% d tre so sinh dugc dieu tri nam dau tien cua giai doan cap tinh. Tre em (tif 6-12 tuoi) bi nhiem man tinh thi ty le khdi benh khoang 60% vdi Benznidazol. Trong khi dd ty le khdi benh lai giam lau hon d ngUdi trUdng thanh bi n h i l m benh Chagas. Neu viee dieu tri cho phu nU bi nhilm benh man tinh trUde va trong sudt thdi ky mang thai khdng giam thi se cd kha nang benh truyen sang thai nhi.
5. Ket luan va de nghi Ket luan
Loai bg xit xua't hien tai nhieu dia phuong d nude ta trong thdi gian vifa qua la Triatoma rubrofasciata De Geer thude gid'ng Triatoma, phan hg Triatominae, hg Reduviidae. Loai nay khdng thuge vao danh sach cac loai bg xit hut mau truyen benh Chagas d chau My. Vdng ddi eua loai bg xit nay trai qua 3 pha phat trien la trufng, thie'u trung va trUdng thanh. Ngoai tU nhien, thdi gian phat trien tif trufng de'n trudng thanh keo dai 1 nam. Trufng nd sau 2-5 tuan, thie'u trimg ed 5 tuoi (qua 4 lan lot xae), trudng thanh ed the dat kich thude 20mm, eon difc ed diem bung ldn hon eon eai.
Bg xit cd the sdng trong khe da, ke tUdng nha, mai nha tranh, ed the bd tren da't, eat hay tren la cay... d cac vimg ddi, nui hay viing ddng bang.
Vuot ban chan Mat kep -•..,. '{
Dot ngae irudc
Ong chan
Ban chan-~-
.' Mat ddn
^---'' Sculellum 1^.^ |~ Tam giac canh
Phan canh sCfng canh
Phan canh mang
Hinh 1. Hinh thai ngoai cua bp xit hp Reduviidae
Hinh 2. Bp xit hut mau 6 thanh phd Hue ( m l u vat bat dupc ngay 29/6/2010
tai Tay Lpc)
Hinh 3. Vdng ddi Triatoma sp 1-4. Trufng; 5-7. Thieu Irung cac tuoi;
8. Trudng thanh; 9. Voi; 10. Phan cuoi bung.
Hinh 4. Triatoma dang hut mau tren mat ngudi (gan mat)
Hinh 5. Triatoma dang hut mau ga
64 Tap chi Nghien cilu va Phat trien, sd 5 (82). 2010
U* I
f^^ Vat chu la dong vat " ^ ^ ^ imi^^ CO XUdng song ^ p f ^ V '
Trypomastigote
fe/1
Amastigote
Bp xit Triatoma Trypomastigote -
xam nhap vao vat chu - ^
^l Epimastigote!
Hinh 6. Vong ddi cua trung roi l<y sinh dUcJng mau Trypanosoma cruzi
Hinh 7. Phan bd benh Chagas 6 chau My (Vung A mau do la vung co lUu hanh benh)'
0 Trong cd the ngudi Hinh 8. Sa lay n h i i m ky sinh trung tCf bp xit vao ngUdi
(1) Bp xit truyen Trypanosoma cruzic^ua cac vet dot va vet thUdng ton Iren da; (2) Khi nhap vao mot te bao cija con ngudi, hinh thanh amastigote; (3) Mot so iUdng Idn amastigote thay trong cac te bao b|
nhilm trong cd; (4) Amastigote chuyen ddi lai thanh trypomastigote, pha vd te bao va tiep luc lay nhiem te bao l<hac; (5) Mpl so trypomastigote vao bo xil; (6) Trong rupt bo xit chuyen thanh epimastigote; (7) Epimastigote s\nh san giai doan thU hai; (8) Epimastigote chuyen thanh metacyclicva dUdc thai qua phan; (1 )J(s phan bp xit lay nhiem sang mot cd the mdi va lap di lap lai chu l<y.
Chung cd the hut mau nhieu loai ddng vat cd xUOng sd'ng, ke ca con ngufdi nhifng khdng phai la loai Ua hut mau ngUdi ma viec hut mau ngUdi chi la ngau nhien. Chung ed mang triing roi ky sinh dudng mau thudc gid'ng Trypanosoma nhUng ehua xae dinh dugc vai trd gay benh d ngUdi eua loai trimg roi ky sinh nay.
Viee phong ngifa bg xit hut mau va dieu tri cae benh do triing roi ky sinh dudng mau gay nen la hoan toan cd the thifc hien hieu qua. Caeh td't nha't de phdng ngifa bg xit hut mau la phat hien va diet bg xit bang bien phap thii cdng vao ban dem, khi bi dot thi lam ve sinh noi bi dot de tranh SLf xam nhap ciia ky sinh trimg. Hien nay phuong phap dieu tri dd'i vdi cac benh nhan cd ky sinh trimg dUdng mau hoan toan khdng ed khd khan gi dang ke dd'i vdi trinh do y hge eua nude ta.
De nghi
Ngudi dan can binh tinh trUde sU xua't hien cua loai bg xit hut mau nay, vi chung la nhufng edn trimg binh thudng, cung nhu eac loai ehan khdp hut mau khae phd bie'n d nUde ta (mudi, rudi vang, rep giudng, bg chet, ve, bet, md, mat...).
Theo chung tdi, can phai sdm tien hanh nghien eufu ve loai bg xit hut mau da neu va nhUng nhdm edn trung sdng gan ngUdi ed kha nang truyen benh. Cac hUdng nghien edu cd the la: 1) Dieu tra xae dinh t h a n h phan loai va dinh danh chinh xae cac loai bg xit hut mau thude phan hg Triatominae d tren toan lanh tho Viet Nam; 2) Nghien cufu sau hon ve dae diem sinh hge, sinh thai hge cua eac loai bg xit hut mau thudng gap; 3) Nghien cufu sU phan bd, vai trd truyen benh cua cac loai bg xit va vai trd gay benh eua eac loai triing roi ky sinh dUdng mau; 4) Xae dinh nguyen nhan phat sinh mot sd' d bg xit vdi mat do ldn... Tat nhien de day nhanh tien do nghien eufu, nang eao hieu qua, can trien khai tren dien rdng, cd sif phd'i hgp eac co quan va nha't la eac nha khoa hge tren mgi mien da't nUde.
Tif eac ket qua nghien eufu dd sdm xua't ban cac tai lieu sach bao chinh thd'ng ve loai bg xit nay de eho ngUdi dan hieu rd ve chung, ed bien phap phdng chd'ng hieu qua, tranh nhUng suf hieu lam, hoang mang, lo sg khdng dang CO.
L T S - L T L T A I L I E U
THAM KHAO
1. Bao cao khoa hpc Hoi nghi Con trung toan quoc lan thil 5 (2005), Nxb Nong nghiep, tr. 84-86.
2. Bao cao khoa hpc Hoi nghj Con trung toan quo'c lan thii 6 (2008), Nxb Nong nghiep, tr. 129-134.
3. Bao cao khoa hpc Hoi nghi Nghien cilu cP ban khoa hpc si/ sdng toan quoc (2005), Nxb Khoa hpc va Ky thuat, tr. 202-205.
4. Bao cao khoa hpc Hoi nghi Nghien ciJu cP ban khoa hpc sg' sdng toan quoc (2007), Nxb Khoa hpc va Ky thuat, tr. 31-345,
5. Bao cao khoa hpc Hoi nghi Sinh thai va tai nguyen sinh vat lan thijf 2 (2007), Nxb Nong nghiep, tr. 128-134; 398-403; 443-450.
66 Tap chi Nghien cilu va Phat trien, sd 5 (82). 2010
6. Bao cao khoa hpc Hoi nghj Sinh thai va tai nguyen sinh vat lan thiJ 3 (2009), Nxb Nong nghiep, tr. 226-234; 235-242; 553-557.
7. Bp mon Ky sinh trung TrUdng Dai hpc Y Ha Noi (1998). Ky sinh triing y hoc, Nxb Y hpc, tr.
60-72; 256-257.
8. Le Trpng SPn (2004). Da dang sinh hge ve con triing d Vudn Qude gia Bach Ma, Nxb Thuan Hoa, Hue, tr. 173-175; 202-204; 281.
9. Vien Bao ve ThUc vat (1976). Ket qua dieu tra con triing nam 1967-1968, Nxb Nong thon. Ha Noi, tr. 78-87.
10. Borror, Donald J. and Richard E. White (1970). A Field Guide to the insects of America North of Mexico. Houghton Mifflin Co. Boston, MA.
11. Daly, Howeli v., John T. Doyen, and Alexander H. Purcell (1998). Introduction to Insect Biology and Diversity. III. Second Edition. Oxford University Press. New York, NY.
12. Geoffrey Lapage (1962). Veterinary Helminthology and Entomology, Fifth Edition. Baltimore the Williams and Willkins company
13. William J. Baerg (1951). Introduction to Applied Entomology, Third Edition. Burgess publishing company, Minnesota.
14. Cac trang web phd thong. Ngudn anh: http://wwww.msgpp.org/ehagas.shtml
TOM TAT
Theo ket qua nghien ciJu cua cac nha khoa hpc, loai bp xit hut mau xua't hien tai nhieu dja phUPng 6 nUdc ta trong thdi gian vCia qua co ten khoa hpc la Triatoma rubrofasciata De Geer, thuoc giong Triatoma, phan hp Triatominae, hp Reduviidae. Loai nay khong thuoc vao danh sach cac loai bp xit hut mau truyen benh Chagas 6 chau My. Chung hut mau nhieu loai dong vat co xUPng sdng, ke ca con ngudi, nhUng viec hut mau ngudi co the chf do ngSu nhien. Chung co mang trung roi ky sinh dUdng mau thuoc gidng Trypanosoma nhung hien nay vSn chua xae djnh dupc vai tro gay benh d ngudi cua loai trijng roi ky sinh nay.
Viec phdng ngUa bp xit hut mau va dieu tri cac benh do trung roi ky sinh dudng' mau gay ra la hoan toan cd the thuc hien hieu qua trong dieu kien cOa nudc ta hien nay.
Chung ta can binh tTnh, tranh nhdng su hieu lam, lo sp khong dang cd trudc viec xua't hien cua loai bp xit hut mau nay, vi chung la nhUng con trung binh thudng, cung nhu cac loai chan khdp hut mau khae phd bie'n d nude ta (muoi, rudi vang, rep giudng, bp chet, ve, bet...).
ABSTRACT
BLOOD-SUCKING BUG - OUR CONCERN
According to research results of scientists, species of blood sucking bug that appeared in many localities of our country in recent times has the scientific name of Triatoma rubrofasciata De Geer, belong to the genus Triatoma, subfamily Triatominae and family Reduviidae. This species is not included in the list of species of bloodsucking bug that transmitted Chagas disease in the America. They suck the blood of many species of vertebrate animal, including human, but their human blood sucking is just random. They carry blood flagellate parasites that belong to the genus Trypanosoma, however the scientific name and human pathogenicity of this species of flagellate parasites is still not determined.
The prevention of blood-sucking bug and cure of diseases caused by blood flagellate parasite are possible in the current condition of our country. We should keep calm, avoid mis- understandings and unfounded fears when this species of blood-sucking bug appear because they are the normal insects as well as other species of blood-sucking arthropod that are popular in our country (eg. mosquito, yellow fly, bed bug, flea, tick...).