KHOA HOC KY THUAT T H U Y TAP XX S(5 5 - 2013
SAC DIEM DjCH T i KHONG 6IAN VA TH0I GIAN CUA HOI CHDNG HOI LOAN SINH S A N V A HO HAP 6 LdN (PRRS)
TAI V I | T NAM, GIAI DOAN 2007-Z01Z
Do Hiru DQng', Nguyen Van Long', Phan Quang Minh', Hodng Van Nam\ Nguyen Viet Khong'
TOM TAT
Chung toi da tien hanh hii curu dii lieu vS djch Hpi chijmg rii loan sinh san va ho hap (PRRS), the die l\rc cao tai 3.694 xS c6 dich trong pham vi ca nuoc tir nam 2007 d8n nSm 2012 d6 phan tich dac diSm dich tl hpc mo ta v8 kh6ng gian va thcri gian.
Phan tich dich tl hpc mo ta cho thay lpn thit va Ion v6 b^o la doi tupng mic benh cao nhit (65,30%) va chet (55,11%), sau do den lpn con, lpn nai va lpn due giong. Sau lan xuat hien dau tien vao thang 3/2007, djch PRRS co xu huong xay ra hang nam vao thang 3-5 a cdc tinh phia Bac va cac thang 7-9 a cac tinh phia Nam, tuy nhien trung binh cii 2 nam mot lan tai bung phat tren dien rong.
Trung bmh m6i nam co 25 trong s6 100 xa nguy ca co dich PRRS, dich xuSt hien tai cac tinh phia Bac, sau do tinh tien dan vao cac tinh phia Nam; dich tram trpng xay ra chu yeu a nhirng ving chan nuoi CO mat dp cao thuoc cac tinh dong bang song Hong, cac tinh Bac Trung Bp va Nam Bp, va djch CO tinh chat lay lan cue bp la chu yeu. Mpt so khuyen cao ve bien phap kiem soat dich benh bang tieu huy lpn benh, kiem soat van chuyen va phSn tich dich te hpc du bao ciing da dupc de cap.
Tic khod: Lan, Hpi chung r6i loan sinh san va ho hip, Dich tl hpc, Khong gian. Thai gian.
Spatial and temporal epidemiology characteristics of Porcine Reproductive and Respiratory Syndrome (PRRS) in Viet Nam, 2007-2012
Do Huu Dung, Nguyen Van Long, Phan Quang Minh, Hoang Van Nam, Nguyen Viet Khong
SUMI\/IARY
A retrospective study was carried out to identify the epidemioiogicai characteristics of outbreaks of the (high pathogen) porcine reproductive and respiratory syndrome (PRRS) occurred from March 2007 to December 2012 all over the country. A total of 3,694 communes having PRRS outbreaks was reported throughout the study period.
Descriptive analyses showed that the fattening pigs had the highest incidence risl^ (65.30%) and highest mortality rate (55.11 %), foliowed by the piglets, sows and boars. Temporal analyses ' Ciic Thli y
= Vifn Thu y
^ Hpi Thu y ViSt Nam
KHOA HQC KY THU^T THtT Y TAP XX S(5 5 - 2013
showed that following the first outbreaks reported in early March 2007, the tendency of epidemics was found annually in March to May in the northern provinces, July to September in the southern provinces. However, the average of large epidemics was re-occurred in every two years. An average with 25 communes in 100 communes yearly facing with the risk of epidemics was reported over the study period. PRRS outbreaks were occurred in northern provinces, gradually spreading all over the central and southern provinces of Viet Nam. Heavy epidemics occurred mainly focusing on the busy pig rearing areas, where high density of pig farms concentrated in the Red river delta, north-central and southern provinces of Viet Nam. Local transmission was the main epidemiological feature. Recommendation on the PRRS control measures by culling infected cases, control of transportation and predictive epidemiology analyses were mentioned.
Key words: Pig, PRRS, Epidemiology, Spatial, Temporal.
I. D A T V A N D E
Hpi chiing roi loan sinh san va ho hip (PRRS) la b?nh truyen nhilm nguy hilm d6i v6i lpn do mpt loai RNA virus co t6c dp lay Ian rat nhanh gay ra. Hi?n co hai dong virus PRRS chinh:
dong chau Au va d6ng chau My. Lpn b^nh co cac bieu hi?n dSc trung viem duang ho hap nhu:
sot, ho, tha kh6. O lpn nai con co cdc bieu hi?n roi loan sinh san nhu: say thai, thai chet luu, lpn sa sinh chit ylu. Nam 1997, virus PRRS chung chau Au da xam nhap vao Viet Nam qua din lpn nhap tir nuac My [1], [3] tuy nhien din thdng 3/2007 benh PRRS mcri chinh thiirc dupc ghi nhan tai Vi$t Nam [8]. Chung virus gay b?nh thupc dong Bac My, dupc coi la chung dpc lire cao vi gay chit nhilu lpn, dSc biet la khi ghep vai cac b?nh khac.
Ke tir khi dich PRRS xuk hien a nu6c ta, nhieu cong trinh nghien cuu dS dupc cong b6.
Nhihig nghien cuu nay chu yeu tap trung vao cac khia canh chan doan phat hi?n b^nh, xdc djnh dpc luc vd kha ndng gay bpnh, xdc djnh ddc tinh sinh hpc phan tir ciia virus va vacxin phong benh. Nhtmg nghien ciru vl dac dilm dich tl cua b?nh con rat ban che, chii ylu mang tinh chat mo td djch o mOt dia phuang. Trong nghien curu ndy, voi nhihig tien bo vl phdn mim phan tich dich tl hpc gan day, chiing toi tiln hanh phan tich diJ ll^u da dupc thu thap tur ndm 2007 den 2012 d8 ldm sdng to mot s6 dac dilm dich te hoc chii yeu ciia b?nh PRRS (loai lpn mSc b?nh, dac dilm khong gian va thai gian) tai Vi?t Nam trong a pham vi ca nu6c.
I. Vat li^u vd phinrng phdp nghi§n ciru 1.1. Solifu
So li?u cac 6 djch PRRS chi tiet den cSp xa do Chi cue thli y cdc tinh, thdnh pho bdo cdo ve Cue thli y tu nam 2007-2012 [2]. S6 lieu chi tilt den cap xa ve tong dan, so hp chdn nuoi lpn theo nien giam th6ng ke 2011 [6]. S6 li?u dia ly chi tiet din cap xa nam 2011 do Nhd xuat bdn Tai nguyen Moi truang va Ban do Vi^t Nam cung cdp [5].
- Phdn mem phdn tich th6ng ke R [11] va cac goi phdn tich tuang ung nhu epiR [13] va Spatstat[7].
1.2. Pftirffngphdp
Thong s6 dich t l theo doi tirgrng mSc benh - Nguy ca mai mdc bpnh (Incidence Risk) cho 1 dan vi thai gian: dupc tinh bdng so xd co dich PRRS chia cho tong s6 xa co nguy co cua mSi tinh cho m6i khoang thai gian.
- Ty le cac loai lpn (d\rc, ndi, Ipn thit va lpn con theo me) mdc benh trong tong s6 lpn mac PRRS vd tuang tir, ty ie cac loai lpn chit trong cdc 6 dich PRRS.
Phtnmg phdp phan tich thM gian - Bieu do dich t l : Bieu d6 mo td t6ng so 6 dich (xa co bdnh PRRS) dupc dim theo ngdy tii:
khi xuat hien ca benh dau tien ciia 6 dich.
Ty s6 ldy lan u^c tfnh (Estimated Dissemination Ratio, EDR): La s6 6 dich PRRS dim dupc cho m^t giai dogn (vi du: 5
KHOA HQC KY THUAT T H O Y TAP XX S 6 5 - 2013
ngdy tuang iing vai khodng thdi gian ii b?nh mmg binh) chia cho s6 6 djch dim dupc cho m6t khoang thai gian tucmg tu, nhung lien kl truoc d6. Vi du: S6 6 dich dim dupc tii ngay 11- 15/1/2008 Id 15, chia cho s6 6 dich dim dupc trong khodng thoi gian tuang t\r, liln kl tru6c do tir 6-10/1/2008 la 12. Nhu v|y, chi s6 EDR = 15/12 >1, cho thay dich dang lay lan. Ngupc lai neu chi s6 EDR <1 cho thdy dich bdt ddu gidm ddn. EDR = 1 cho thdy djch 6n dinh (khong tdng, khong giam).
Phirtfng phdp phdn tfch khong gian Tpa dO dia ly X va Y dugc ghi chep cho timg 6 dich PRRS (xd c6 dich). Bdn d6 Kernel [4], [10], [12] the hien du li?u dang diem, trong do mdt dO diSm dich (uac tinh mat dp Kernel) ty 1?
vcri tdn s6 Idp lai ciia dich tai cung tpa dp.
Trong phdn bo khong gian (bdn do Kernel), ty so nguy cff (risk ratio) Id so xa co dich PRRS tren tong so xa co nguy ca trong pham vi khong gian la moi km^.
Mlic ldy lan cue bO hay tren diSn rOng dupc ddnh gid d^ra vdo phdn tich chdm khong gian- thdi gian. Chiim khong gian ca bpnh PRRS dupc xdc djnh bdng phuang phap thdng ke sdng lpc khong gian [9] vdi s\r h6 trp ciia phdn mim SaTScan m6 td phdn bo ca b?nh theo khong gian vd thbi gian th6a mdn cdc an dinh: (i) Nguy cp c6 dich PRRS dupc xem Id dong kha ndng cho moi xd vd tuan theo phdn bo Poisson; (ii) Khung khong gian dupc dn djnh Id 50% tong s6 xS co nguy ca; (iii) Khung thdi gian dupc dn djnh la 21 ngay (tuang duang khoang thdi gian tir ca b?nh cu6i din ngay cong bd hit dich); (iv) Xac nh$n s\r xudt hien chiim khdng gian-thdi gian tai dp tin cay thing ke (p < 0,05) sau 999 ldn lap lai theo phuang phap Monte Carlo [9].
n . KET QUA VA THAO LUAN 2.1. Nguy ccr co djch PRRS theo dja phuong va doi tUflTig Ipn
Hoi curu so lieu trong 6 nam (2007-2012) theo tinh va nguy ca co dich PRRS cho moi tinh dupc thong ke d bang 1 vd mo td d bieu do hinh 1.
Bdng 1 : Nguy c d c a c t l n h c o d j c h PRRS q u a c a c n a m 2 0 0 7 - 2 0 1 2
TT 1 2 3 4 5 6 7
a
9 10 11 12 13 14 15 16
Tinh CO djch PRRS Thanh ph6 Ha Noi Thdnh pho Hdi Phong Ttnh B i o Ninh Tlnh Hdi Daong Ttnh Hung Yen Ttnh Ha Nam TTnh Nam Djnh Tlnh Thai Binh Tinh Nmh Binh Tinh Cao Bang Tinh Lao Cai Ttnh B&c Kan Tinh Lang Son Tinh Tuy§n Quang Tinh YSn Bai Tinh Thai Nguyen
Tong s ^ xa 577 223 126 265 161 116 229 286 147 199 164 122 226 141 180 180
So xa c6 dich PRRS
75 10 78 75 26 4 46 60 12 22 19 25 45 23 23 21
Nguy cd co djch (%) PRRS (95% Cl)
13(10,36-16,02) 4,48(2,17-8,09) 61,9(52,83-70,41) 28,3 (22,96 - 34,14) 16,15(10,83-22,76) 3,45 (0,95 - 8,59) 20,09(15,1 -25,87) 20,98(16,41 -26,16) 8,16(4,29-13,83) 11,06(7,06- 16,26)
11,59(7,12-17,5) 20,49(13,72-28,75) 19,91 (14.91 -25,72) 16,31 (10,63-23,46) 12,78(8,28-18,55) 11,67(7,37-17,28)
KHOA HQC K? THUAT THp Y TAP XX SO 5 - 2013
TT 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Tlnh Cli dich PRRS Tinh Phli Tho Tinh BSC Giang Ttnh QuSng Ninh Ttnh Lai OhSu Ttnh Dl$n Bi6n Ttnh Son La Ttnh H6a Binh Tinh Thanh H6a Tinh Ngh$ An Ttnh Hi Ttnh Ttnh Qudng Tri TtnhThCtaThiSn-Hue Thdnh phS Dd N i n g Ttnh Qudng Nam Tinh Qudng Ngai Tinh Binh Dmh Tinh Phil Ydn Ttnh Khdnh Hoa Ttnh Kon Tum Ttnh Gia Lai Ttnh Dik L8l<
Tinh Ddls N6ng Tinh Ldm Oong Tinh Ninh Thuan Tlnh Binh Phudc Ttnh Tdy Ninh Ttnh Binh Duong Ttnh D6ng Nai Ttnh Binh Thuan Tinh Bd R|a-Vung Tdu Tinh Long An Tinh Tien Giang Tinh VTnh Long Tinh B^n Tre Ttnh Kidn Giang Thdnh ph6' Cdn Thd Tinh Hdu Giang Tinh Trd Vinh Tinh Sdc Trdng Tinh Bac Lieu Tinh Ca lUlau T^ng s6
l6ng B6 xa 277 230 187 98 112 206 210 637 479 262 141 152 56 240 183 158 112 137 97 222 184 71 148 65 111 95 91 171 127 82 190 169 107 164 136 65 73 104 109 64 101 9985
S6 x i cd dich PRRS
15 63 53 2 24 7 9 460 160 76 63 35 17 102 13 3 18 84 14 16 110 16 27 9 73 73 14 27 5 38 81 70 12 19 51 11 3 1 35 17 39 2529
Nguy c d c 6 djch (%) PRRS (95% Cl)
5,42 (3,06 - 8,77) 27,39 (21,74 - 33,64) 28,34 (22,01 - 35,38) 2,04(0,25-7,18) 21,43(14,24-30,19) 3,4(1,38-6,88) 4,29(1,98-7,98) 72,21 (68,56 - 75,66) 33,4(29,19-37,82) 29,01 (23,59-34,91) 44,68 (36,31 - 53,26) 23,03(16,59-30,54) 30,36(18,78-44,1) 42,5(36,16-49,02) 7.1 (3,84-11,84) 1,9 (0,39 - 5,45) 16.07 (9.81 - 24,21) 61,31 (52.62-69,51) 14,43(8,12-23,03) 7,21 (4,18-11,44) 59,78 (52,32 - 66,93) 22,54(13,46-34) 18.24(12,38-25,42) 13,85(6,53-24,66) 65,77(56,16-74,51) 76,84 (67,06 - 84,88) 15,38 (8.67 - 24,46) 15,79(10.67-22,14) 3,94 (1,29 - 8.95) 46,34 (35,25 - 57,7) 42,63 (35,5 - 50) 41,42(33.91 -49,24) 11.21 (5.93-18,77) 11,59(7,12-17,5) 37,5 (29,35 - 46.21) 12,94(6,64-21,98) 4,11 (0,86-11,54) 0,96 (0,02 - 5,24) 32,11 (23,49-41,73) 26,56(16,3-39,09) 38,61 (29.09 - 48,82) 25,33 (24,48 - 26,19)
KHOA HQC KY THUAT THO Y TAP XX S6 5 - 2013
i^;a4+++^-+^ Httli.|HtWt«<* Htt I*
*t
P , l ^ 5 | .
i i i 3 | l i i | i i j i | f 3 , a i i j l | i i ? | i l | i i i i f ^ i l | | i f | | i j i | i | | 5 i i l i
0 . O O z o S 3 a i = > - u i z ^ c D f l E i i - 3 j z m F Q Q P a ) a i r a x o S z l 2 0 F Hlnh 1: Nguy CO c6 dich PRRS theo tlnh nSm 2007-2012
^0
Tli nam 2007 den ndm 2012, tong cpng cd 3.881 d dich PRRS da xudt hien tai 57/63 tinh thdnh, tru cdc tinh Hd Giang, Vinh Phiic (phia Bdc) Qudng Binh (Trung bp), TR H6 Chi Minh, An Giang, 0dng Thdp (phia Nam). Dich da xudt Men d 2.529/11.098 (23%) xa, phudng trong pham vi ca nudc. Mdc dii khdng cd sd lieu ghi chep den cap hd chdn nudi lan, nhung vdi miic dp luu hdnh vd gdy benh rpng rai cua virus PRRS nhu nhung nam qua, cd thi thdy, viec dieu chinh chinh sdch phong chdng dua vao viec tieu buy nhung lpn mdc benh ddu tien cua 6 dich nen dupc xem xet lai. Cdc tinh chua tiing bao cdo cd dich PRRS khdng co nghia la chua cd virus PRRS luu hanh va gay benh d ddy; rat cd the da cd cdc truang hap benh nhd le rai rac xdy ra nhung dupc phdt hien vd xii ly kip thdi.
Viec gidm sdt va bdo benh a cac tinh chua c6 bdo cao dich la rat quan trpng, ddc biet doi vdi nhung tinh cd nguy ca rdt cao xudt hien PRRS nhu tinh Qudng Binh - ncri tilp giap vdi cdc tinh CO dich la Ha TTuh vd Qudng Tri, Iai nam dpc tren tuyin dudng Qudc Ip 1.
Nguy ca trung binh cdc tinh cd benh PRRS Id 25,33 xa cd dich/100 xa-ndm dao dpng trong khodng 24,48-26,19. Nguy ca ndy thay ddi qua cdc ndm vd miic nguy ca tuy thudc dia phuang;
mpt sd tinh cd nguy ca xuat hi?n dich PRRS rdt cao nhu Tay Ninh, Thanh Hda, Binh Phuoc, Bac
Ninh, Khdnh Hoa, Dak Ldk (> 50%).. .ngupc Iai mdt sd tinh cd nguy ca thdp nhu Trd Vinh, Binh Djnh, Lai Chdu, Son La.. .(< 5%, bieu dd a hinh 1). Sd lieu phdn tich nguy ca a bang 1 kha phii hpp vdi tinh hinh dich PRRS tren thuc te, dia phuang cd nguy ca xuat hien dich cao chinh Id cdc tinh cd djch PRRS xdy ra hang nam va thudng d miic dp tram trpng.
- Su khdc biet ro rang v^ nguy ca cd dich PRRS gifta cac tinh (bang 1, hinh 1) co the do:
Tai cac tinh cd nguy ca cao, Ipn chan nudi d mat dp dan ldn, cd dudng qudc Ip di qua; cdng tdc kiem djch van chuyen chua triet de (dac biet Id ngay tu khi dich mai xuat hien) dan den dich ldy lan giua cdc xa lien ke. Ket qud phan tich khdng gian phli hop voi nhdn xet tren vi chiim khdng gian cac ca benh tap trung d cdc tinh nguy ca cao (hinh 4), nghTa Id dich PRRS cd tinh chdt ldy lan cue bd tai cac dja phuang ndy. Ngupc lai, tai cdc tinh cd nguy ca thdp nhu Lai Chdu, San La, mac du cd dich xudt hien, nhung do mat dp chdn nuoi lpn thdp, giao luu budn bdn van chuyen lpn tai cdc dia phuang ndy khong nhieu nen djch thudng khong xudt hien tren dien rpng.
Mpt sd dja phuang do td chiic tdt cdng tdc kiem djch van chuyen (nhu Binh Djnh), dich dupc khdng chl ngay, khdng Ian rpng.
D6i tupng lpn mdc benh vd chet do PRRS
KHOA HQC KY THUAT T H O Y TAP XX S(5 5 - 2013
Bing 2: T9 1$ \<)n 6m vk ch^t do PRRS trong glai do^n 2007-2012
L09I l^n
Oi/c Ndi Ldn con Ldn thjt T6ng stf
S66m
1.234 79.235 85.372 312.027 477.668
T j l « 5m
(%)
0,26 16,58 17,87 66,30
Khodng dao d^ng
(%)
0,12-0,35 16,51 - 16,70 17,79- 17,99 65,27 - 65,49
S6 c h A
& tl6u hu^
645 9.039 16.070 31.614 57.368
T } \i chft
& tidu hu^
(%)
1,12 15,76 28,01 55,11
Khodng dao dOng
(%)
1,01 -1,25 15,3-15,89 27,36 - 28,09 54,14-56,95
chlit-TH/eim
(%)
11,41
'
18,82 10,13 12.00
Phdn tich vl co cdu Io?i lpn mdc b?nh vd chet (bdng 2) do PRRS trong giai do^n 2007 - 2012 cho thdy ty 1$ lpn thit bi b^nh Id cao nhat 65,30%, sau dd din lpn con (17,87%), lpn ndi (16,58%) vd !pn dye giong 0,26%. Tuang tu ty 1^ chet theo ca cau lo^i lpn ciing Id cao nhat d nhdm lpn thjt, sau dd din nhdm lpn con, lpn ndi va Ipn dgc (55,11%; 28,01%; 15,76% vd 1,12%). Nhin chimg ty 1§ lpn chet/tong so dm trong khoang 12% dao dpng tuy ddi tupng: C) lpn con Id 18,82%, lpn ndi Id 11,41 % va lpn thjt la 10,13%. Ddi v6i lpn d\rc, ty 1? chlt/dm khdng tinh do thieu dir Ii?u dl lupc tach sd giet loai.
- Su khdc bi?t r5 rang vl sd lupng vd ty Ip cdc loai lpn bi b?nh vd chet do PRRS trong giai doan 2007 - 2012 cd the do nhung nguyen nhan khdc nhau: (i) Ca cdu ddn quylt djnh tdng sd Ipn cd nguy co theo nhdm Id khdc nhau; trong thyrc
te, tong ddn lpn d\rc, Ipn ndi la rat nhd so voi tong ddn lpn con va tdng ddn lpn thjt, do vay, khi cd djch, c6 nhilu lpn thjt, lpn con bj b^nfa va chit; (ii) dieu kipn chdm sdc nuoi dudng khac nhau (cao hon ddi vdi Ipn due gtdng va lpn ndi, ngay cd vipc tiem vacxin phdng b|nh ciing triet di& hem); (iii) khd ndng dap ung miln djch, chdng chpi vai mdm b^nh phdn ndo tity thupc vao lira tudi, cao hem a nhdm Ipn nai, di;c gion^
thdp han cr lpn con va lpn hudmg thjt ngdn ngay.
Ngodi ra, ciing can luu y sd Heu bao cdo thing ke CO y nghia tdng thi, vdi mpt sd dja phucmg, so lieu ve ty le dm vd chet theo ddi tupng lpn co the thay doi do chinh sdch hd tra tdi chinh dli vdi nguoi chdn nudi cd gia siic phai tieu hiiy va cac ylu td xa hpi khdc.
2.2. Ddc dilm thM gian cua dich PRRS giai doan 2007 - 2012
J^Jkkl
Ngdy c6 ca ti^nh diu tidn cOa 6 d|ch
Hlnh 2: Diin bl^n theo thai gian cia cic 6 dich PRRS glal Oofn 2007 - 2012
KHOA HQC K? THUAT T H O Y T ^ P XX S 6 5 - 2013
Bilu dd djch t l tai hinh 2 cho thay trong giai do?n 2007 - 2012, cd ba dpt djch I6n PRRS xdy ra vdo cac dpt thdng 3 - 5 ndm 2008, thdng 5 - 9 nam 2010 vd thdng 5 - 9 ndm 2012. Nhu vdy, sau ldn ddu tien djch PRRS xuat hi§n vdo dau didng 3/2007, hdng nam, dich van rdi rdc xuat hi?n; tuy nhien cd thi thay cii khoang 2 ndm l^i xudt hipn cac dpt djch trdm trpng: 2008, 2010 vd2012.
- Dich PRRS tdi bimg phdt sau khodng 2 ndm CO the nhdn djnh do sau m6i ndm djch trdm trpng, cac bi^n phdp phdng ch6ng dupc triln khai tich eye nhu tieu d ^ khu trung, han chl van chuyen va tifim vacxin phdng b?nh; tdc
dyng ciia nhfhtg bi^n phdp ndy cd thi tilp t^c dupc duy tri d ndm kl tilp, do v§y djch xdy ra it tr4m trpng han. Din ndm thii 2 sau dpt djch, cdc bi^n phdp phdng chong djch cd the khong dupc chii trpng ddy dii trong khi dd phan 16n ca c4u ddn da thay doi va virus PRRS vdn luu hdnh rpng rdi, n€n djch I^i tdi biing phdt.
- Tli ndm 2007 din ndm 2012, djch PRRS cd xu hudng xdy ra trdm trpng vdo cdc thdng 3 - 5 vd cdc thdng 7 - 9 . D$c tinh miia v^i ndy cd thi do trung vdi thfri dilm tdi ddn, tdng tdng ddn lpn nudi, va k^m theo dd Id si^ tdng luu lupng v§n chuyin lpn, nguy ca cho b^nh xudt hifn vd ldy sang cdc dja phuang khdc.
Ngdy c6 CB bfnh iliu tlAn
Hinh 3: T^ s6 l&y lan UOc tlnh (EDR) cua djch PRRS nim 2010 vd ndm 2012 so vdi s6 lUtfng 6 dich thtfc tS xay ra. [Ehtomg mdu do the hi?n ty le lay lan uac tinh, dirang mdu xanh dut qudng the hi^n cgn tren vd can duai cua khodng tin cgy 95%. Duong thdng dung mdu xanh ddm the
hi^n so 6 dich (xd co dich) PRRS dugc dim theo nggy co ca benh ddu tien].
Bieu do ty so Idy lan udc tinh (EDR) cua dich PRRS a hinh 3 cho thdy: Trong ndm 2012, mac dil dich PRRS xdy ra rai rdc vdo cdc thdng trong nam, nhung miic dp djch Id khdng trdm trpng. Dich chi cd xu hudng phdt triln manh vdo cdc thdng 3, thdng 7 vd thdng 8 khi cd ty sd Idy Ian udc tinh 16n han 1. Sd lifu vl sd xd cd djch tai bilu do 6 hinh 3 cung cho thdy vdo ddu thdng 12/2012 cd 30 xd bdo cdo djch xudt hifn cung ngdy. Ddy la mdt khd ndng rdt hilm. S6 lifu CO thi dd khdng dupc bdo cdo kjp thdi vao thdi diem trudc dd.
Sii dyng bieu dd ldy Ian udc tinh cd the cho phep chiing ta du dodn sa bO khi ndo djch bdt ddu xay ra tram trpng, khi ndo djch sS len d§n dinh diem vd khi ndo c6 ddu hieu djch gidm dan. Vifc ghi chep sd lifu chi tiet, cdn thdn, ddy du vd chinh xdc se giiip cho vifc du bdo thoi dilm djch xudt hifn vd c6 cdc hifn phdp phdng chdng phil hpp, khong de djch trdm trpng xdy ra, cung nhu cd ca sd huy dpng cac ngudn l^rc phong chdng.
KHOA HOC KY THUAT THp Y TAP XX S6 5 - 2013
2.3. D^c dilm kh6ng gian cia dich PRRS giai do?n 2007 - 2012
Ban do dang diem
Nam 2008:
Ban do dang diem
Nam 2009:
Ban do dang diem
Nam 2010:
Ban dd dang diem
8- 1- 1- 8-
h-
f^ 1 -
s ] a - 1 -
^f ^
iL
I D S 4 1 Ole 1 a>8u,
]
iT * ^
Nam 2007: Bdn do Kernel - Risk ratio
Ndm 2008: Ban do Kernel - Risk ratio
Nam 2009: Ban do dang dilm - Risk ratio
Nam 2010: Ban d^
Kernel - Risk ratio
KHOA HOC KY THUAT THU Y TAP XX SO 5 - 2013
Nam 2011:
Ban do dang diem
Nam 2012:
Ban dd dang diem
N5m 2007-2012:
Ban do dang diem
1-
Ndm 2011 Ban do Kemel - Risk ratio
Ndm 2012: Ban do Kemel - Risk ratio
Ndm 2007-2012:
Kemel - Risk ratio
Mat dp so xa cua ca nitoc; Ban do Kemel
Hinh 4: Phan bo I(h6ng gian cOa cdc 6 dich PRRS giai do?n 2007 - 2012.
Cdc chdm mau do: vi tri dfa ly cdc xd co dich. Cdc vung co mdu tie do nhgt den do thdm. ty so nguy caxa CO dich PRRS cho moi km'. Vong tron mdu xanh: vung cua chiim khong gian ca benh PRRS.
KHOA HQC K? THUAT T H O Y T ^ P XX S 6 5 - 2013
Kit qud phdn tich djch te hpc khong gian d hinh 4 cho th^y djch PRRS xu^t hifn t^ii cdc dja phuang mien Bdc, sau dd dd djch chuyen vdo cdc dia phuang miln Trung vd mien Nam.
- Ndm 2007 (dau thdng 3): Djch PRRS lan ddu tien xuat hifn t^i miln Bdc, sau dd t?i mien Trung vd cd xdy ra rdi rdc t?i mien Nam.
- Nam 2008: Djch dd c6 xu hudng tjnh tien tir Bdc vdo Nam, djch khdng cdn tram trpng nhdt tai cdc tinh dong bdng sdng Hdng (nhu ndm 2007) md dd xay ra trdm trpng t^i cdc tinh Bdc Trung Bp (gdm Thanh Hda, Nghf An, Hd Tinh).
Ndm 2008, phdn tich rd sodt thong ke khong gian cho thay, chiim ca bfnh eye bp tai cdc dja phucmg ndy.
- Nam 2009: Djch xdy ra rdi rdc t^i ba mien Bac, Trung vd Nam.
- Nam 2010: Dich da dich chuyen r5 net vao cdc tinh mien Nam, mdc dii djch cung dong thdi xuat hifn tram trpng tai cdc tinh ddng bdng sdng Hdng. Phan tich rd sodt thong ke khdng gian cho thdy chiim khdng gian ca bfnh PRRS Id rat ro net.
- Nam 2011: Djch xdy ra rai rdc tai ba miln Bac, Trung va Nam.
- Ndm 2012: Tuang tu nhu ndm 2010, djch cung xuat hifn tram trpng tai cdc tinh mien Nam va ddng bdng sdng Hong. Phan tich ra soat thdng ke khdng gian cho thdy chum khdng gian ca benh PRRS la rdt rd net tai hai viing nay.
- Ddc diem phdn bd khong gian ciia djch PRRS la tap trung tai vung cd m§t dp chdn nudi cao, cd luu lupng buon ban van chuyen ldn, va/
hodc gdn liSn vdi tryc Ip giao thdng, bao gdm cdc tinh dong bdng sdng Hdng, cdc tinh Bdc Trung Bp, va djch trdm trpng nhdt 6 cdc tinh phia Nam.
- Ket qua phdn tich chiim khdng gian ca bfnh cho thdy cac chum ca bfnh triing hpp vd tap trung cue bp tai nhiing tinh cd dich trdm trpng, chiing td mdc dii djch xudt hifn 6 nhilu nai, nhung djch cd tinh chdt ldn lan cue bp la chu ylu.
III. KfiT LUJ^N
- Ve doi tupng mdc bfnh: Bfnh PRRS trdm trpng nhat d lpn thjt, sau dd din lpn con, lpn ndi vd lpn dvrc gidng.
- v l thdi gian: Tuy djch PRRS xay ra la te hdng ndm nhung tdi biing phdt tren difn rpng 2 ndm 1 lan. Cd thi dy bdo sy tdi xudt hifn ciia o djch dva tr§n phdn tich ty sd ldy lan udc tinh.
- v l khong gian: nguy ca xudt hifn dich PRRS Id thudng tr\rc vd rdt Ion, trung binh mli ndm Id 25 trong sd 100 xd cd nguy co. Djch PRRS cd tinh chat Idy Ian chu yeu tai cue bp dja phuong nai cd djch, chiim khdng gian ca bfnh t^i cdc vung dich Id khd rd rang va tap trung d viing dong bdng sdng Hong, khu vuc phia Nam vd Bdc Trung Bp, nai cd mgt dp chdn nudi cao, duang Ip thuan lpi cho s\f van chuyen gia sfic.
Til nhirng ket qud phdn tich md td, chiing toi cd nhirng de xuat sau:
- Chinh sach tieu huy lpn mdc bfnh din thdi diem hifn tai cd hifu qud mong mudn thdp ve kinh te vd phong bfnh do virus PRRS dd vd dang luu hanh rpng rai d khodng 23% sd xi, phuang ciia 57/63 tinh, thdnh.
- Cdn ddc biet quan tdm cdng tdc Idem djch van chuyen Ion, nhat Id van chuyin lien tinh do djch thudng xuyen xudt hifn tai cdc dja phuong cd cdc tuyen duang qudc Ip di qua, va trong lich sir dich lay tii phia Bdc vao phia Nam cung gdn lien vai duong van chuyen theo Qudc Ip.
- Sit dung cdc phuang phap nghien ciru djch tl hpc djnh lupng de phdn tich chuyen sau, danh gid lupng hda cdc yeu td nguy ca anh hudng den sy ton tgi, lim hdnh vd phdt tdn cdc d dich PRRS, cung cdp ca sd khoa hpc ndng cao cdc bif n phdp phdng chdng bfnh.
TAI LIEU THAM KHAO
1 Biii Quang Anh, Hodng Van Ndm, Vdn Ddng Ky, Nguyen Vdn Long va Nguyin Ngpc Tien (2008). Hpi chiing rdi loan sinh sdn va hd hap d lpn va cac vdn bdn chi dao, hudng dan
KHOA HQC K? THU^T THU Y TAP XX $6 5 - 2013
phdng chong. Tdi Uf u hudng din kJ thudt sd 63, phien ban 630, NN-2008. Nhd Xudt bdn Ndng nghif p. Ha Npi, Vif t Nam.
2. Cyc Thli y (2012). Bdo cdo tdng kit cong tac phdng chdng dich bfnh gia sue, gia cdm nam 2012. Ha Npi, Vift Nam: Cyc Thii y.
3. Nguyin Luang Hiln vd Ngo Thanh Long (2001). Budc ddu khdo sat hpi chiing rdi '• loan sinh sdn vd hp hdp d mpt sd trai heo gidng thufc vimg thdnh phd Ho Chi Minh.
Bdo cdo khoa hpc, Phan chdn nudi thii y 1999 - 2000, trang 244 - 247. Hd Npi, Vift Nam: Vien Thii y.
4. Nguyin Vdn Long, Phan Quang Minh, Chu Dire Huy vd Dd Hiru Diing (2013). Tdng quan ve iing dung hf thdng thdng tin dja ly trong thii y. Tgp chi Khoa hoc ky thugt thiiy sd 2 (1).
5. Nhd xudt ban Tdi nguyen Mdi trudng va Bdn dd Viet Nam (2012). Ban dd hanh chinh Vift Nam.
6. Tdng Cue Thong ke (2012). Ket qud Tdng dieutrandngnghiepvd thuy sdn ndm 2011.
Tdng Cue Thdng ke, Hd Npi, Viet Nam.
7. Baddeley A. & Turner R. Spatstat (2005):
An R Package for Analyzing Spatial Point
Patterns. Journal of Statistical Software 12, 1-42.
8. Feng, Y. et al. (2008). Porcine respiratory and reproductive syndrome virus variants, Vietnam and China, 2007. Emerg Infect Dis 10.
9. KuIIdorff M (1997). A spatial scan statistic.
Communications in Statistics-Theory and methods 26, 1481-1496.
10. Pfeiffer, D. et al. (2008) Spatial analysis in epidemiology. Oxford University Press New York, USA.
11. R Development Core Team (2012). R: a lan- guage and environment for statistical com- puting. R Foundation for Statistical Version 2.15.2 [computer program].
12. Stevenson M. (2012). Investigation of Spa- tial Patterns of Animal Disease. Epicen- tre, IVABS, Massey University Palmerston North, New Zealand.
13. Stevenson M. et al. (2013). An R package for the analysis of epidemiological data.
Package 'epiR' Version 0.9-48.
Nhan ngdy 20/4/2013 Phan bien ngdy 3/5/2013
TRUNG QUOC MAT HON 6 TY USD VI H7N9
Tcr Thai bao Bac Kinh hom 20/5, trich din mpt vien chiic cao cap nganh chan nuoi Trung Quoc cho bilt, dich cum gia cdm H7N9 tir culi thang 3 da lam cho nganh nay thiet hai hem 40 ty yuan (6,5 ty USD).
Theo to bao nay, nguyen nhan gay thiet hai to Ion la viec ngudi dan Trung Quoc so bi lay nhiem, nen khdng dam an ga vit. Tir truoc den nay, ga vit chiem mpt phan rat quan trong trong bira an, nhung voi cac dpt cum nii tilp nhau, lupng tieu thu loai thjt nay dd giam manh.
Trong cdc thdng qua, cd 130 ngudi bj nhilm virus H7N9 t^i Trung Quoc, trong do 35 ngucri bj thift mang, theo cac s6 lieu chinh thiic mdi nhit. Loai virus nay dupc cho la khong truyen tii ngudi sang ngudi.
Theo vien chiic tren, lupng gia cam ban ra trong cac thang qua da sut mpt each tham hai, va gia mat hdng nay da tuft die. Gioi chdn nuoi bj 16 ia, bupc phai sa thai nhan cong.
Theo hang tin AFP, dl tao lai sir tin tuong nai ngucri tieu thy, cac vien chiic tinh Son Dong va mot so Idnh dao trong nganh chan nuoi d Trung Quoc da to chiic mpt biia tiec chi vdi cac mon thjt ga. Bita tiec da dupc truyin thong loan tai rpng rai.
Nh.Thgch (Tfieo AFP)