OAC DieM D|CH Te HOC BENH CUM MUA TAI VIET NAM GIAI DOAN 2006-2013
Nguyen Thi Thu Yen', Le Quynh Mai', Tran Nhu Dinmg', Nguyin Hai 'Hian', Nguyen Phuvng Thanh', Nguyen Bifin Tbuy', Nguyin Lfi Khinh HSng', Vu Dinh Thilm', Vfl Hai Hi*', IVin Ngpc HuiiS Phan Trpng Lan^ Nguyen Thanh Long\ Bill Trpng Chien\ Vien Quang Mai^ Trjnh Thi XuSn Mai^ D§ng Tuin Dgt^, Pham Thp Du^c*- Vo Thj Hudng*, Nguyfin Trin Hiln'.
' Vifn Vf sinh Dich ti Trung uang, Hd Npi 'Vi$n Pasteur thanh pho Hd Chi Minh 'Vifn Pasteur Nha Trang
'Vifn Vf sinh Dich te Tdy Nguyen
T O M T A T
Thuc hifn nghifin cmi d|ch tfi hpc mfi tfi dfi dSnh giS die difim djch tfi vS su' li/u hSnh cfia vi rut cum mita t^i ViSl Nam. Sfi lifiu dirgrc thu thSp tCr Hfi thfing giam sfit cum qufic gia trong giai do^n 2006-2013. Kfit quS cho thfiy t^ Ifi dircmg tinh/ sfi mau xfit nghifim it bfinh nhan hfii chi>ng cum IS 20,8%. Bfinh cum xufit hi$n quanh nSm vS thu&ng cfi 2-3 iSnh dich/ nSm, vdi dinh cao nhat thu&ng thfiy tiF thSng 6 dfin thSng 9. Ty Ifi duvng tinh cao nhfit d nhfim tufii 5-14 diifim 29,1%. Vi nJt cum phfi bifin nhfit IS typ B vS cSc phSn h;^ A/
H3N2,A/H1N1 pdm vfi A/H1N1, dfing iiru hanh quanh nam vSlfinlirgI thay nhau chifim U'U thfi. Cum Beo ti Ifi diKmg tinh nhifiu nhat fi' nhfim tufii 5-14. nhirng cum A/H1N1/2009 cfi tJ Ifi duwng tinh cao cr nhfim tufii 15-24. Ciim miia IS mfit bfinh phfi bifin vS chifim ty l | cao trong tfing sfi hfii chi>ng cum. Mfi hinh bSnh cfim fi' Vifit Nam gifing nhu* si/ kfit hp'p cOa mfi hinh cfim fir cSc nirfic fin dfi'i if cS Bfic bSn cfiu vS Nam bSn cfiu.
Ti> khfia: Bfinh cum mua, vi njicum, djch cum, cum B, aim A/HI Nl, cumA/H3N2.
I. DAT VAN DE
VI rut cum li mgt nguyen nhin chmh giy b$nh dufing hfi hap if nguoi vi gay ra ganh n$ng bpnh t^t dang ke doi vai sfte khfie cpng dong [1]. Bpnh eiim cfi thi xiy ra hing nam theo mua, hoac thinh thoing bung phit dai dich eftm d i xiy ra tren quy mo toin eiu. Bpnh cfi khi nang lay nhilm rat eao, liy tryc tiep tu ngufii bpnh sang ngucri linh thfing qua cie gipt bin nhfi khi nfii chuypn, khi ho, hat hai [2].
Tren the giai cae vy dieh cum hang nam gay ra 3-5 tripu ca bpnh n ^ g va khoing 250000 - 500000 ngufii chit [3]. Tai Viet Nam cic vi rut gay benh eum mua thucmg gap la cum A/
H3N2, A/HIN1 v i eftm B [4].
Trufirc day hpi ehftng cum (HCC) dupc
giam sit ttong hp thing giam sat 26 bpnh truyen nhiem quic gia a Vi?t Nam, nhung do ban che ve ngufin lyc va mfte dp uu tien nen HCC chira dupe quan tira dung muc. Tft nSm 2006, Bp Y Tl, Vien Vp sinh Dieh te Trung uong da phfii hop vai Tnmg tam kiem soit va ngfin ngfta bfnh t$t Hoa Ky (CDC) thye hipn xay dyng Hp thfing giim sit cum trpng diem tai Vipt Nam nham thu thip cae thong tin ein thiet v l dich te hpc vi vi rut hpe cua bfnh ciim 6& dl ra cac ehinh sich va bipn phip phong ehing djch eftm kip thai va hipu qui, dfing thai tftng buac phat trien mang lufii giira sat cum a Viet Nam. Nhu li mpt phin cfta hopi dpng giam sal, nghien cftu nay eho biSt siu ban ve dac dilm djch te hpc cua benh cum mua tai Vipt Nam.
•Tic gia' Vu Hai HA
Dja chi: Vi?n V? smh D)ch te Trung uong Di?n thm- 04 38211732/0983019099 Email: dr.vuhaiha(a yahoo com
Ngay nh^n bai: 02/03/2015 NgSy phSn bien: 30/03/2015 NgSy dang bai: 20/04/2015
T9P chf Y hpe dy phfing, T?p XXV, S l 3 (163) 2015
IL PHlTONG P H A P N G H I E N CUtJ 2.1 Thiet ke nghien cihi
Nghien cftu dich te hpe mo ti theo dfii loat ca bpnh HCC
2.2 Thoi gian va dia dilm nghien ciru Thoi gian nghien cuu: Giai do^n 2006-2013 Dia diem nghien cuu: Thyc hi$n tai 16 diem giam sat a cic vimg sinh thai khic nhau tten toan qufic (7 diem fi Mien Bic, 4 diem Mien Tnmg, I diem Tay Nguyen va 4 diera Miln Nam). Cac diem giam sit dupc chpn raang tinh d^ii dipn cho mfit khu vyc/tieu khu vyc ve cic d§c diem sinh thai vcri mftc dp giao Iuu lon, phin b l theo khu vyc thanh thi - nong thfin.
2.3 Doi tirprng va phmmg phip thu thip miu Cic bpnh ea HCC t^i cie diem giim sat ttong giai d o ^ 2006-2013: Cic ca bpnh phu hpp vod djnh nghTa HCC: S6t dpt ngpt > 38°C, Ho vi/ho^c dau hpng vi ehua cfi chan doin nao khic.
Thu thip miu bpnh pham: Thu thip mau bpnh pham ngoay hpng hoac djch tiet dufing ho hap. Moi ngiy thu th^p 2 mlu bpnh pham eua 2 bpnh nhan HCC dau rien efi thfii gian khai phit ttong vfing 3 ngiy tinh den ngay lay miu.
Bfnh phim dupc bao quan a nhipt dp 2-8''C toi da ttong vong 72h tft khi liy miu tai diem giim sit, nlu liu ban phai bao quan a nhipt dp -TO^C. Miu bfnh pham dupe gfti 2 lan/tuan ve Vifn Vp sinh Dieh tl/Pasteur. Trong qui trinh v^n chuyen miu bSnh pham phai duoc gift a nhipt dp Ii4°C.
Xet nghipm vi rut eum bang ky thuit PCR t^i phong x6t nghifm Vifn Vf sinh Dich tl
Trung uang.
2.4 Xu ly v i phan tich so lipu
Thu th^p sfi lieu: Kit qui xet nghiem dupe thu tiiap ttj bio eao kit qui xet nghifm hang tuin eua phfing xet nghiem eic Vipn Vp sinh Dich tl/Pasteur.
Sfi lifu vl benh nhan din khim, sfi hpi ehftng cum va eic thfing tin dich ll khic nhu tufii, gioi, thing nam mSe benh dupc tbu th§p tu Phieu dieu tta ca bpnh va Bio cio hing tuin tft cic diem giam sat.
s l lieu dupc pban tieh bing Stata 12.0 (Sta- ta Corporation, College Station, TX, USA).
2.5 Dao dire nghien cuu
Nghien eftu khong vi pham dpo dfte ng- hiSn cftu vi nim ttong khuon khfi xay dyng h? thong giam sat eftm efta Vift Nam da dupc dong y cua Hfii ding khoa hpe vi y due ciia Vifn Ve sinh dich te Trung uang va chap thuin bai Bfi Y tl. Cic tic gia li nhung nguoi tryc tilp tham gia vio ho^t dfing giim sit eum dfing thfii dupe sy cho ph^p eua co quan quan ly de khai thac sft dpng sfi lipu cho phin tich, tong hpp vi viet bio.
II!. K E T QUA 3.1 Ph4n bo bfnh theo dia du
Trong tfing s6 41689 bpnh nhan HCC dupc thu th§p mau bpnh pham va Iam x^t nghifm tft thing 01/2006 din thing 12/2013 efi 8667 mau duong tinh vfii vi nit eftm, chiem ty If 20,8%.
Cung ttong thfii gian tten, HCC dupc ghi nhan tfii 10,7% cua so bfnh nhan den khim bfnh (Bang 1).
Tap chi Y hpc dy phfing, T$p XXV, Sfi 3 (163) 2015
BSng 1. Tt Ifi h$l chu^g cum trong tfing sfi IthSm vS sfi duwng tinh trong tfing sfi xfit nghipm theo Ithu vyc
Sfi b$nh nhSn dfin . % HCC/Sfi Sfi xet Sfi duomg % dtrtmg tinh/sfi Sfi HCC .
kham dfin kham nghl|m ttnh xfit nghifim MiSn BSc
MiSn Tmng TSy NguySn MiSn Nam Tong s6
1547M2 64S225 231581 2026866 4454014
205153 45366 40754 185562 476835
13.3 7.0 17.6 9.2 10.7
17260 8748 3943 11738 41689
3499 2015 610 2543 8667
20.3 23.0 16 5 21.7 20.8
Ty lp duang tinb eum B tten tfing so xet nghifm theo typ vi nit li cao nhit fi eic khu vyc Mien Nam, Tay Nguyen va Toin q u i e
(Hinh 1). Trong khi dfi Mien Bae v i Mien Trung efi ty If duang tinh vdi eum A/H3N2 nhieu han.
Hinh 1. Ty lfi duwng ttnh /so xSt nghifm theo phSn typ vi nit ciim
T9p chi Y bpc dy phfing, Tap XXV. S l 3 (163) 2015 39
3.2 Phan bl bfob theo thfii gian Kit qua nghien ctru cho thay so ea duong tinh voi vi rut eftm xuat hien quanh nam.
Trong mpt nam thufimg efi 2-3 dinh dich, vi ty le duong tinh eao nhit thudng thay tu thing 6
din tiling 9, ttong dfi nhieu nhit 3/8 nim dinh dich vio tiiang 7, cfi 1/8 nim dinh djch l?i vio thing 2. Thfing tiiuang tiii cfi dinh chinh d mua he thu va dinh phy fi mua dfing xuin va ngupc lai (Hinh 2).
%duvnatlnWsAxttnghl«m
Hinh 2. Sfi ca dwyng tinh va ty 1$ duwng tinh trfin sfi xfit nghifim
So duang tinh phan tiieo mim cum a Bic ban ciu (tft thing 11 din thing 4) va Nam ban cau (tu thing 5 den thing 10) eho tbay cie ea ducmg
tinh ehu yeu vao thing 5-10 vi it hon a thing 11- 4. Cie typ eum A ehu ylu vio thing 5-10 ttong khi cum B chu ylu vio thing 11-4 (Bing 2).
BSng 2. Ty Ifi duwng tinh cum theo miia cum if Bac bSn cfiu vS Nam bSn cfiu
MiSn B^c
MiSn Tmng
TSy NguySn
MiSn Nam
Todn qu6c com A COmB TSng CilmA CCimB TSng CCimA CumB TSng Cum A CCimB TSng Ciim A Cum B TSng
Bcic bdn c^u sSca
661 711 1372 493 483 976 101 158 259 345 461 806 1600 1813 3413
(Thang 11.4) 28.7
%
59.6 39 2 36.2 73.9 48.4 28.2 62.7 42 5 21.0 51.1 31.7 28.2 60.4 39.4
Nam bdn cSu sSca
1646 481 2127 868 171 1039 257
94 351 1296 441 1737 4067 1187 5254
(Thang 5-10) 71.3
%
40.4 60.8 63.8 26.1 51.6 71.8 37.3 57.5 79.0 48.9 68.3 718 39.6 60.6
2006-2013 sSca 2307 1192 3499 1361 654 2015 358 252 610 1641 902 2543 5667 3000 8667
40 Tap chf Y hpc iv phong, Tjp XXV, S6 3 (163) 2015
Bing 2 cho ta thiy trong su6t thiri gian tvr ghi nhan tii nam 2008-2010 ma dinh 14 nam 2006-2013, ty duong tinh ciim cao hon dupc 2009 (Bang 3).
Bdng 3. KSt qua xSt ngh)$m RT-PCR theo ndm, 2006-2013
TSngsS 2006 2007 2008 2009 Ndm 2010
2011 2012 2013 TSng
SSxdt nghidm SSca 41689 4625 6467 6975 7401 4405 4444 3429 3943 41689
sS dircmg Unh SSca 8667 947 1167 1489 1942 979 651 674 818 8667
20.8
%
20.5 18 21.3 26.2 22.2 14.6 19.7 20.7 20.6
A/H1N1 SSca
1296 574 16 643 63 0 0 0 0 1296
3.1
%
12.4 0.2 9.2 0.9 0 0 0 0 3.1
B SSca 3000 315 272 618 454 505 174 398 264 3000
7.2
%
6.8 4.2 8.9 6.1 11.5 3.9 11.6 6.7 7 2
AJH3N2 SSca 2871 56 875 221 722 379 20 267 331 2871
6.9
%
1.2 13.5
3.2 9.8 8.6 0.5 78 8.4 6.9
A/H1N1 pdm SSca
1470 0 0 0 696
94 455 9 216 1470
3.5
%
0 0 0 9.4 2.1 10.2 03 5.5 3.5
llhdc SSca
30 2 4 7 7 1 2 0 7 30
0.1
%
0 0.1 0.1 0.1 0 0 0 0.2 0.1
% so dircmg linh Iren so mdu xel n_
Ket qui a bing 3 eho thay sau nim 2009, khong ghi nhin cum A/H IN 1 vi ciing bit diu tu nam niy (7/2009) da phat hifn cum A/HIN- Ipdm. Cfi mpt \y Ie nhfi khie (0,1%) gim cie dfing nhiem A/H3N2 & B, A/HINl & B, A/
HlNl pdm & B v i A khfing phan typ xetnghifm thiy ttong giai d o ^ niy. Sy phan b l cie phin typ vi nit cum trong tong so duong tinh cho thay cfi 4 loai phfi biln nhit li B, A/H3N2, A/HINI pdmviA/HlNI. Sy luu hanh eua chiing ciing khfing gifing nhau a cie thing (Hinh 3). Ty lp
xet nghiem ducmg tinh vfii 4 vi nit cum tten nhin chung tang cao cfi tinh chu ky khoang 2 nam rapt lin. Ni nit cum B va A/H INI xu huoTig cfi ty lp duang tinh cao vio nhftng nim chin. Ty lp duong tinh cua A/HlNI/2009 ting cao vao nhutig nam le. Con vi nit ciira A/H3N2 tang cao vao nhftng nara 2007,2009,2010,2012 vi 2013.
VI riit cum B thufing cfi ty le duang tinh tang cao vio thing II den thing 4 ngoai trft nam 2010.
Con cic typ cum A nhin chi'mg thuang tang eao vao cic thing 5 din thing 10.
1;H 7101 4,7 101 "1 '101 'l,7aqi,f1,71Ql,4 7IQl 4 71(11 fl,7iPj I 2006 I 2007 ' 2008 \ 2009 j 2010 1 2011 | 2012 | 2013 \
t. PhSn b6 cSc phSn typ vl rut cijm trong ting s i duwng tinh theo thSng, 2006-2011 Tpp ehi Y hpc dy phfing, T§p XXV, Sfi 3 (163) 2015
33 Phin bo bpnh theo tuoi v i giiH Ty If duang tinh vai ciim so viji tong s l ca xet nghiem (Bang 3) cho thiy nhfim 5-14 tiili l i nhfim chiu inh huotig nhilu nhat (29,1%), vi nhfim tufii niy cung li nhfim cfi ty le duang tinh vfii cum B nhilu nhit. Dli v6i phin typ
eftm A/HINI pdm tiii lai cfi t^ If ducmg tinh cao a nhom 15-24 tufii, tilp theo mfii li nhfim 5-14 tuli. Ty le duang tinh cum a nam li 21,2% vi fi nft li 20.3%. Theo phin t>p vi nit eftm ty If niy gin nhu tuong duong nhau tru ty Ip ciim B fi nam eao hon la 7,6% so voi nft la 6,8% (Bing 4).
Bang 4. Kit qua x6t nghi$m RT-PCR theo nhom tu6i, giai nSm 2006-2013.
S6 xSt So duwng nghidm tinh
A/HINI pdm
S6ca S6 S6
ca ca
5-14 Nh6m 15-24 tuSi 25-64
>64 TSng
10216 4736 10203 1336 41689
15198 2572 16.9 370 2.4 819 5.4 1069 7 306 10216 2972 29.1 404 4 1250 12 2 746 7.3 562 1105 23.3 166 3.5 329 6.9 302 6.4 305 1863 18.3 328 3.2 550 5.4 683 6.7 293 155 11.6 28 2.1 52 3,9 71 5.3 4
8667 20.8 1296 3.1 3000 7 2 2871 6.9 1470 3.5 30 0.1
Giin nam na tong
21074 20615 41689
4477 4190 8667
21.2 20.3 20.8
657 3.1 639 3.1 1296 3.1
1595 1405 3000
76 6.8 7.2
1466 1405 2871
7 746 6.8 724 6.9 1470
3.5 3.5 35
13 17 30
0.1 0.1 0.1 id ducmg tinh Iren so mau xel nghidm
IV. BAN LU.^N
Ket qua ngbien cuu ebo thiy ttong giai do^m 2006-2013, bpnh cum mfta la mpt bfnh pho biln. Tuy nhien ty If 20,8% duang tinh tten tong so xet nghipm li thap hon con sfi 42% eua rapt nghidn cftu tai Bangkok eua Prachayangprecha et al [1]. Sy khie bift co the do nghien cuu t?i Bangkok t^p trung tai thinh phfi Ifin dong dan eu eon nghien cftu cua chung tfii trii dii 15 dilra tten toin quoc. Mpt ty If thip a Tay Nguyen (15.5%) efi the do ehi thyc hipn nghien cuu tai rapt dilm a khu vye Daklak nai mat dp dan s l khong dong ttong khi eie khu vye khie thye hien nghien eiru tai nhilu dilm han. Nhin chung, nhilm vi nit cum Ii mpt nguyen nhin quan ttpng cfta benh nhin efi HCC.
Khie vdi viing fin d<^, noi xuit hifn bfnh eum cfi tinh chit mua rfi ring vi chi cfi mfit dinh dieh vio nhiing thing mua dong [5], bfnh
cum miia o Vipt Nam xuat hien quanh nim voi 2-3 dinh dich rieng bipt moi nam. Thufing dinh dieh chinh vio khoing thai gian mua dong xuin efta Nam bin eau (thing 5-10) vi dinh phy vio mua dfing xuan cua Bie bin eiu (thing 11-4). Ty lp duang tinb eftm eao hon vio thai ky mua cum a Nam bin cau vi thap hem fi thai ky mua cum fi Bic bin cau. Mic du ea bpnh xuit hifn quanh nim, thfn gian tiem phong cum nen can nhie tfii eic dinh dfch chinh vio giua nim, thcri ky mfta eftm fi Nam bin eau.
Ginh n$ng bfnh eftm theo dp tiafii cho tiiiy nhfim Xxh di hpc 5-14 tuli Ii nhfim ehiu inh hufing nhieu nhat, dieu niy ciing phu hpp vfii bio cao t^i Cbangsha -Trung Quic khi rai ty If duong tinh eao nhat a nhfim 5-14 hili [6].
Dfii voi A/HINI pdm thi lai co ty lp duong tinh eao a nhfim 15-24 tufii, tilp theo li nhfim 5-14 tuli. Dieu niy phu hpp vai nghien cftu trufifc diy t$i Bangkok kbi ty 1^ cao doi vai A/
42 T?p chi Y hpe dy phfing. Tip XXV, S l 3 (163) 2015
HlNl pdm a nhfim ttifii 5-24 ttong giai doan 2009-2010 [1]. Nhfim 5-14 ttili Ii nhfim cfi ty Ip duong tinh vai ciim B nhilu nhit, cfi the do eum B chu yeu inh buong tdi tte em [7]. Mpt nghien euu t^ii Canada eho bilt ty If duang tinh vai cum B cao nhit 6 nhfim tufii 5-19 [8].
Dae diem vi nit hpe dya trfin cic so heu phan tieh ve di ttuyin vi dac dilm khang nguyen eua vi rut eftm luru hinh tten ngufii tai Vift Nam cho thay co sy tiln hfia thucmg xuyfin ctia vi nit cum mfta tai Vift Nam vi dfiu theo sy tiln hfia ehung eua vi nit cum Iuu hanh ttfin thi gifii, cic vi nit eftm luu hinh t^i Vift Nam duong nhu cfi dp tuang dong cao ve thfii gian xuat hipn, die tinh khing nguyen voi eac vi nit cftra luu hanh tai eie nuoe thupe khu vye Nam ban cau [9].
Sy luu hinh efta 4 loai vi nit cum pho bien nhat li B, A/HINI, A/H3N2 v i A/HlNl/2009 nhin chung cfi tinh chu ky khoing 2 nim mfit lin.
Khfing quan sit thiy sy trung dinh giua eftm A vi eftm B. Dieu dfi eho thay sy luin phifin luu hinh vi gay djch gifta eic typ vi nit.
Ket qui efta nghifin cftu eho thiy sy ein thiet cua duy tri eong tic giam sit thuang xuyfin. Vi giim sit dieh te hpe vi vi nit hpe cum li mpt ho^t dfing quan ttpng d l eung cip thfing tin cin thilt cho dilu chinh ehiln lupc tiem phfing. Giim sit lien tpe eie die tinh efta vi nit eftm luu hinh l i rit quan ttpng di theo dfii phu hpp cua nfi vai cac ehftng vie xin theo mua [10]. Trong boi cinh hien nay, sy thay dfii lifin tuc cua eie phin typ vi nit ciim mfta hay nhu sy xuit hipn cic phan typ ciim gia cam mfii H7N9, H10N8... lufin d^t ra nhu eiu cin thilt cho sy duy tri he thong giim sit eftm tpi Vipt Nam. Dilu niy khfing nhftng dfing gfip tot hon eho sy hieu biet vfi d$e difim djeh t l hpe vi vi nit hpe eua cum tten quy mfi toin ciu ma cfin thifit thye ting cufing nang lye giim sit, dy bio vi phfing ehing dich, dai dieh ciim cua Vipt Nam.
V. KET LV^N
Kit qui eho thiy bfnh etim li bfnh phfi bien vi chiem ty 1? eao (ty le duong tinh
20,8%i) ttong tfing sfi bfnh nhan dupe ehin doin hfii ehftng ciim. Ty If duang tinh cao nhit 6 nhom tuoi 5-14 chilm 29,1%. Vi nit cum pho bien nhit Ii cum B vi cie phan tip A/
H3N2, A/HINl pdm vi A/HINl, 4 loai vi nit ttfin lin lupt thay nhau chiem uu the ttong ty If mlu xet nghifim duang tinh. Nhfim 5-14 tufii la nhfim cfi ty If duong tinh vai cum B nhifiu nhit, ttong khi vfii eftm A/HINl pdm thi lpi efi ty lp ducmg tinh cao a nhfim 15-24 tuoi. Sy xuat hien eua bpnh ciim quanh nim vfii nhifiu dinh dich mfit n5m eho thiy mfi hinh bfnh eftm miia a Vift Nara gifing nhu sy ket hpp cua mfi hinh eftm fi cac nufic fin d6i fi e i Bic bin ciu va Nam bin eau. Vifc giam sit thudng xuyen vfi dae difim dieh te bpc, sy Itm hinh l i rat can thiet va co y nghta cho cfing tic phfing chfing cum tai Vipt Nam.
L&i cdm an:
Nhfim tie gii xin cam an cie Vifn Vf sinh Djch tfi/Pasteur, Trung tam Y tl Dy phong, bpnh vipn efta eie tinh, thanh phfi cfi difim giira sit cum, cic khoa phong cua Vifn Vp sinh Dieh tfi Tnmg uang da epng tie vi giiip dfi chung tfii hoin thinh nghifin cftu niy.
TAI LIEU THAM KHAO
1. Prachayangprecha S, Makkoch J, Suwannakam K,
\^chaiwattana P, Korkong S, Theamboonlers A, Poovorawan Y. Epidemiology of seasonal influenza in Bangkok between 2009 and 2012. J bifect Dev Qries, 2013; 7(10): 734-740.
2. Cyc Y ^ dir phong vA moi trudng Bp Y t£. Benh Ciim. Trong Cim nang phong chong b?nh tnry&a nhiem. Ha NOi, 2009,122-130.
3. World Health Organization. Influenza (Seasonal) Fact sheet N°21I March 2014. ht^://www.who.
int/mediacentTe/factsheets/fs211/en/recievedon 13 Mar. 2015.
4. Bp V t^. Hudng din chin doin va di^u tn b?nh ciim mua - Ban hanh kem theo Quyet dinh so 2078/QE>- BYTngSy23thSng6nam2011 ciia Bp tnrcmg Bp Ytg. Ha Npi, 2011.
5. Simonsen L. The global impact of influenza on mor- bidity and mcHtaUty. \tonDe 1999; 1 7 S i w l l : S 3 - SIO.
6 Chen JF, Sun BC, Yuan J, Zhang RS, Ou XH Sur-
T a p ehi Y hpc d u phfine. T a n X X V *;A i ( 1 6 3 ) 2 0 1 5
veillance of influenza virus dunng 2010-2012 in Changsha, China. Southeast Asian J Trop Med Pub- lic Health 2014; 45(2): 319-325.
CDC. Influenza - Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book:
Course Texfeook - 12th Edition Second Printing hnpV/www.cdcgov/vaccmes/pubs/pinkbook/flu.
htmlrecievedon I3Mar,2015.
Canada Communicable Disease Report CCDR.
Statement on Seasonal hifluenza Vaccine for 2013- 2014. Public Health Agency of Canada 2013; 39:
ACS-1
Vi?n V? sinh Dich te Trung mmg - Bp Y te. Hpi thao I6ng ket dy an gifim sat ciim quic gia 2006- 2010 Do Trung tam Kiem soat va Phong ngira Benh t^t (CDC) Hoa Ky tai tn?. Ha Npi, 2010.
Panani E, Amendola A, Piatti A, Ansehni G, Rangh- iero A, Bubba L, Rosa AM, Pellegnnelh L, Binda S, Coppola L, Gramegna M, Zanetii A. Ten years (2004-2014) of influenza surveillance in Northern Italy. Hum Vaccm Immunother, 2015; 11(1): 198- 205.
EPIDEMIOLOGICAL CHARACTERISTICS OF SEASONAL INFLUENZA IN VIETNAM, PERIOD 2006-2013
Nguyen Thi Thu Yen', Le Quynh Mai', Tran Nhu Duong', Nguyen Hai T^ian', Nguyen Phuong Thanh', Nguyen Bien Thuy', Nguyen Le Khanh Hang', Vu Dinh Thiem', Vu Hai Ha', Tran Ngoc Huu^ Phan Trong Lan^
Nguyen Thanh Long^ Bui Trong Chieng Vien Quang Mai^ IVinh Thi Xuan M a i \ Dang Titan Dat*, Pham Tho Duoc^ Vo Thi Huong^, Nguyen Tran Hien'.
'National Institute of Hygiene and Epidemiology, Hanoi 'Pasteur Institute Ho Chi Minh City
'Pasteur Institute Nha Trang
^Institute of Hygiene and Epidemiology of Tay Nguyen
To evaluate the epidemiological characteristics and the eireulation of seasonal influenza viruses in Viediam, a descriptive epidemiology stucfy was carried out, using data collected fiom the Nation- al Influenza Surveillance Systems during 2006- 2013. The results showed that the proportion of influenza positive/ number of tested samples in influenza-like illness (ILl) patients was 20.8%.
Cases occurred throughout the year and usual- ly had 2-3 peaks per year, with the highest peak fiom June to September. The highest proportion of influenza positive was m the age group of 5-14 years old, aceounted for 29.1%. The most com- mon of influenza vims were type B and subtypes
A/H3N2,A/H1N1 pdm viA/HlNI,they co-eir- eulated year round and in tum dominated. Influ- enza B virus had the most proportion of positive in the age group of 5-14, and A/HlNIpdm had a high proportion of positive in the age group of 15-24. Seasonal influenza was a common disease and a high proportion of ILI in Vietnam. Influen- za model in Vietnam was like a combination of the influenza in temperate countries of the both Northern and Southem hemispheres.
Keywords: Seasonal influenza. Influenza vims. Pandemic Influenza, influenza B, influ- enza A/H IN 1, Influenza A/H2N3, Vietiiam
Tap ehi Y hpe dy phfing, T§p XXV, Sfi 3 (163) 2015