Common vampire bat attacks on humans
in a village of the Amazon region of Brazil
Ag re ssõ e s d e mo rc e g o s he mató fag o s a p e sso as
e m um p o vo ad o d a re g ião amazô nic a d o Brasil
1 Pan Am erican Health Orga n iz a t ion . 525 23rd St reet N W, W a sh in gt on , DC 20037- 2895, U .S.A. 2 Scien ce Com m u n ication St u d ies. 5457 M a rsh Ha w k W a y, Colu m b ia , M D 21045, U .S.A. 3 In stitu to d e Salu d Am b ien t e y Tra b a jo. Cerra d a d el Con v en t o 48- A, Tla lp a n , DF 14420, M éx ico. 4 Dep artam en to d e Zoologia, In st it u t o d e Biociên cia s, Un iv ersid a d e Est a d u a l Pa u list a . Bot u ca t u , SP 18618- 000, Bra sil. 5 Un iversid ad Nacion al Au t on óm a d e M éx ico. Ed ificio d el IIM AS, Ciu d a d Un iv ersit a ria , M éx ico, DF 045190, M éx ico.
M a ria Crist in a Sch n eid er 1 Joa n Aron 2
Ca rlos Sa n t os- Bu rgoa 3 W ilson Uied a 4
Sílv ia Ru iz - Vela z co 5
Abst ract M a n y p eop le in Am a z on ia n com m u n it ies h a v e rep ort ed b a t b it es in t h e la st d eca d e. Bit es by v a m p ire ba t s ca n p ot en t ia lly t ra n sm it ra bies t o h u m a n s. Th e object iv e of t h is st u d y w a s t o a n a lyz e fa ct ors a ssocia t ed w it h b a t b it in g in on e of t h ese com m u n it ies. A cross- sect ion a l su r-v ey w a s con d u ct ed in a r-v illa ge of gold m in ers in t h e Am a z on ia n region of Bra z il (160 in h a b i-t an i-t s). Bai-t s w ere cap i-t u red n ear p eop le’s h ou ses an d sen i-t i-t o a lab. Of 129 p eop le in i-t erv iew ed , 41% h a d b een a t t a ck ed b y a b a t a t lea st on ce, w it h 92% of t h e b it es loca t ed on t h e low er lim b s. A lo-gist ic regression fou n d t h at ad u lt s w ere bit t en arou n d fou r t im es m ore oft en t h an ch ild ren (OR = 3.75, CI 95%: 1.46-9.62, p = 0.036). M ales w ere bit t en m ore frequ en t ly t h an fem ales (OR = 2.08, CI 95%: 0.90- 4.76, p = 0.067). N in e D e sm o d u s ro t u n d u sa n d t h ree fru giv orou s b a t s w ere ca p t u red a n d t est ed n ega t iv e for ra b ies. Th e st u d y su ggest s t h a t , in a n a rea of gold m in ers, com m on v a m -p ire bat s are m ore lik ely t o at t ack ad u lt s an d m ales. Th e con t rol st rat egy for h u m an rabies d evel-op ed in t h is region sh ou ld t h erefore p lace sp ecial em p h asis on ad u lt m ales. Th ere sh ou ld also be m ore resea rch on h ow t h e sea rch for gold in t h e Am a z on ia n region p la ces p eop le a n d t h e en v i-ron m en t at risk .
Key words Agression ; Ch irop t era;De sm o d u s ro t u n d u s
Resumo Agressões d e m orcegos a p essoa s v êm sen d o n ot ifica d a s em v á ria s com u n id a d es a m a -z ôn icas n est a ú lt im a d écad a. Ist o con st it u i u m risco p ot en cial p ara a raiva h u m an a t ran sm it id a p or m orcegos. O objet ivo d est e est u d o foi d e an alisar fat ores associad os a est as agressões em u m a d est a s com u n i d a d es. Foi rea li z a d o u m est u d o t ra n sv ersa l em u m p ov oa d o d e ga ri m p ei ros n a Regi ã o Am a z ô n i ca b ra si lei ra (160 h a b i t a n t es). Fo i rea li z a d a a ca p t u ra d e m o rcego s ju n t o à s ca sa s e f o ra m en v i a d a s a m o st ra s p a ra o la b o ra t ó ri o. D a s 129 p esso a s en t rev i st a s, 41% f o ra m a gred id a s p or m orcegos p elo m en os u m a v ez , com 92% d a s m ord id a s loca liz a d a s n os d ed os d os p és. Por m eio d e regressão logíst ica, en con t rou -se qu e ad u lt os eram agred id os ao red or d e qu at ro v ez es m a is d o q u e cria n ça s (OR = 3,75, IC: 1,46- 9,62, p = 0,036). Hom en s fora m a gred id os com m a ior freq ü ên cia d o q u e m u lh eres (OR = 2,08, IC: 0,90- 4,76, p = 0,067). N ov e De sm o d u s ro t u n -d u se t rês m orcegos fru gív oros fora m ca p t u ra d os e resu lt a ra m n ega t iv os p a ra a ra iv a . O est u d o su gere q u e, em á rea s d e ga rim p o, a d u lt os d o sex o m a scu lin o t êm m a ior p rob a b ilid a d e d e serem a gred id os p or m orcegos. As a ções d e con t role p a ra a ra iva h u m a n a a serem d esen volv id a s n est es lu gares d evem d ar ên fase esp ecial a ad u lt os h om en s. Recom en d am -se m ais in vest igações sobre o m od o com o o garim p o n a Região Am az ôn ica est á colocan d o em risco as p essoas e o am bien t e.
Introduction
Th e ve r y first se ttle rs o f th e Am e rica s re p o rte d in cid en ts o f b a ts a tta ckin g p eo p le a n d ca ses o f h u m a n ra b ie s t ra n sm it t e d b y t h e se a n im a ls in t h e e a r ly 16t h c e n t u r y (Ba e r, 1982). He m a t o -p h a go u s b a t s in h a b it a t e rr it o r y ra n gin g fro m t h e No r t h o f Me xico t o t h e No r t h o f Arge n t in a (Lo rd e t a l., 1975). Th e re a re t h re e sp e c ie s o f b a ts th a t feed o n b lo o d :Dip h ylla ecau d ata, Di-aem u s you n gi, a n d Desm od u s rotu n d u s (Uied a , 1989). Th e la t t e r sp e c ie s, a lso kn own a s t h e com m on vam p ire, sp ecializes in b leed in g m a m -m a ls a n d is p rob a b ly resp on sib le for a tta cks on p eop le (Green h a ll, 1988).
Ba t s c a n t ra n sm it va r io u s d ise a se s t o h u -m a n s, su c h a s a r b ovir u s d ise a se s ( Ta -m sit t &a-mp; Va ld ivie so, 1970), h ist o p la sm o sis a n d t r yp a n o so m ia sis (Co n sta n tin e, 1988), le yp to syp iro -sis, rickettsio-sis, a n d cryp tococcosis ( Ta m sitt & Va ld ivie so, 1970), a n d b ru ce llo sis, sa lm o n e llo -sis, a n d ca n d id ia sis (Co n sta n tin e, 1988). How-e vHow-e r, t h How-e m o st sHow-e r io u s d isHow-e a sHow-e t h a t c a n b How-e t ra n sm it t e d b y b a t s is ra b ie s. Th is d ise a se h a s ca u sed n u m erou s d ea th s in La tin Am erica over t h e la st se ve ra l d e c a d e s, wh e re t h e b a t h a s b e e n id e n t ifie d a s t h e se co n d m o st im p o r t a n t a n im a l sp e cie s in th e tra n sm issio n o f ra b ie s to h u m a n s (INPPAZ, 1997).
Th e fir st o u t b re a k o f h u m a n ra b ie s t ra n s-m itted b y h es-m a to p h a go u s b a ts rep o rted in th e sc ie n t ific lit e ra t u re t o o k p la c e in Tr in id a d in t h e 1930s, wh e n 55 p e o p le d ie d ( Ve r t e u il & Ur ich , 1935). Fro m t h e 1930s u n t il t h e p re se n t a p p roxim a tely o n e th o u sa n d d ea th s a ttrib u ted t o va m p ire t ra n sm it t e d ra b ie s h a ve b e e n re -p o rted , a n d th is n u m b er is -p ro b a b ly a n u n d er-estim a te (Alva rez, 1997). Th e co u n tries th a t re-p o r t e d t h e m o st ca se s b e t we e n 1990 a n d 1995 we re Pe r u (78) a n d Bra zil (43) (Alva re z, 1997). Ca ses of ra b ies tra n sm itted by va m p ire b a ts oc-cu r re d m o st ly in a re a s wit h d iffioc-cu lt a cce ss in th e Am a zo n re gio n o f th e se co u n trie s (Sch n e i-d er & Sa n tos-Bu rgoa , 1995).
Th e re a re va r io u s re p o r t s o f va m p ire b a t s a tta ckin g h u m a n s with o u t th e a tta ck b ein g fo l-lowe d b y ra b ie s. Th is o b vio u sly d e p e n d s o n h ow wid e sp re a d t h e vir u s is in t h e a re a . So m e o f t h e se a t t a c ks h a ve t a ke n p la c e a m o n g in -d ige n o u s p o p u la t io n s, su ch a s t h e Ya n o m a m i in Ven ezu ela in 1979 (Alm a n sa & Ga rcia , 1980). No t e t h a t in t h e la t t e r c a se d e fo re st a t io n h a d ta ken p la ce in th e a rea a s a resu lt o f lu m b erin g a n d go ld p ro sp ectin g; it wa s a lso rep o rted th a t th e p o u ltr y b e in g ra ise d in th o se co m m u n itie s h a d b e e n ra p id ly e xt e r m in a t e d b e fo re t h e a t -t a c ks s-t a r -t e d . In 1975, a se r ie s o f a -t -t a c ks o n p eop le wa s rep orted in Belize a fter th e swin e in
t h e a re a h a d b e e n sla u gh t e re d (Ma c Ca r t h y, 1989). Go ld p ro sp ecto rs in Ro ra im a , Bra zil, a re freq u en tly a tta cked by b a ts (Uied a et a l., 1996). A se rie s o f a t t a cks in a villa ge in a ru ra l a re a o f Bra zil wa s a scrib e d t o b o t h lo ca l e n viro n m e n -t a l ch a n ge s a n d a -t o p ica l p e s-t icid e a p p lie d -t o ca ttle (Costa et a l., 1993). Alth ou gh th ere a re rep o rts o f b a ts a tta ckin g rep eo rep le in va rio u s co u n -t r ie s, -t h e e x-t e n -t o f -t h e p ro b le m a n d i-t s a sso ci-a ted risk fci-a ctors ci-a re n ot kn own .
Th is p a p e r e xa m in e s fa c t o r s a sso c ia t e d wit h h igh in cid e n ce o f va m p ire b a t a t t a cks o n h u m a n s, id e n t ifyin g a p o t e n t ia lly h igh risk fo r h u m a n ra b ies.
M ethods and materials
A c ro ss- se c t io n a l st u d y wa s c o n d u c t e d in t h e villa ge o f Min a Nova o n th e isla n d o f Au rizo n a , in t h e c o u n t y o f Go d o fre d o Via n a , lo c a t e d in th e extrem e n orth ern region of Maran h ão State, p a rt o f th e Am a zo n regio n o f Bra zil (01o16’ 18”
Fo r t h e b iva r ia t e a n a lysis, t h e fa c t o f e ve r h a vin g b een a tta cked by b a ts in Min a Nova wa s c o n sid e re d a ye s/ n o fa c t o r, wh e re “ye s” a n d “n o” a re a n a lo go u s t o c a se s a n d c o n t ro ls in a ca secon trol stu d y. Th is va ria b le wa s crossta b -u la t e d o n e b y o n e wit h p o ssib le e xp la n a t o r y (o r “e xp o su re”) va r ia b le s in o rd e r t o e st im a t e a n o d d s ra t io (OR) (ra t io o f e xp o su re o d d s am on g cases to exp osu re od d s am on g con trols) a n d t o a p p ly Fish e r’s o n e -t a ile d e xa ct t e st . Fo r e a ch p o ssib le e xp la n a t o r y va r ia b le, t h e se t wo p ro c e d u re s a n a lyze t h e p ro p o r t io n o f p e o p le b it t e n in re la t io n t o t h e va lu e o f t h a t va r ia b le (e.g., p rop ortion of m a les b itten versu s p rop or-tion of fem a les b itten ).
Fo r t h e m u lt iva r ia t e a n a lysis, a lo gist ic re -gression m od el wa s d evelop ed , u sin g h istory of b a t a t t a c k a s t h e d e p e n d e n t va r ia b le a n d t h e sign ifica n t va lu es from th e b iva ria te a n a lysis a s t h e in d e p e n d e n t va r ia b le s. STATA ve r sio n 5 so ft wa re (STATA Co r p o ra t io n , 1997) wa s u se d fo r a ll st a t ist ica l a n a lyse s. Th e fin a l m u lt iva r i-a t e i-a n i-a lysis m o d e l wi-a s se le ct e d b y co m p i-a rin g t h e like lih o o d o f t h e re d u c e d m o d e l wit h t h a t o f th e co m p le te m o d e l, u sin g th e eq u a tio n G = - 2 ln (like lih o o d o f t h e re d u c e d m o d e l/ like li-h o o d o f t li-h e c o m p le t e m o d e l). Va r ia b le s we re reta in ed in th e fin a l m o d el if th e m o d el’s fit u s-in g t h e m wa s sign ifica n t ly im p rove d a s sh own by th e G sta tistic.
In a d d it io n t o in d ivid u a l in t e r vie ws wit h resid en ts, b a ts were ca p tu red a t n igh t to d eter-m in e wh e t h e r t h e ra b ie s vir u s wa s circu la t in g in t h e a re a . Th e re se a rc h e r s se le c t e d h o u se s wit h a h igh p ro b a b ilit y o f b e in g t a rge t s fo r co m m o n va m p ire s, su ch a s th o se with d o m e st ic a n im a ls o r wist h p e o p le wh o h a d b e e n a st -t a c ke d re c e n -t ly. Ne -t s fo r c a p -t u r in g b a -t s we re p la c e d o n c e in e a c h h o u se fo r a p e r io d o f 5 h o u rs in th e ea rly even in g. In 5 h o u ses in Min a Nova , 10 n e t s m e a su r in g a b o u t 6 m e t e r s e a ch we re se t u p t o t ra p b a t s. Ca p t u re d b a t s we re se n t t o a re fe re n ce la b o ra t o r y (Cen t ro d e Z oo-n oses d e São Pau lo) t o b e d ia gn o se d fo r ra b ie s in fectio n (im m u n o flu o rescen ce a n d b io lo gica l tests) (Sch n eid er et a l., 1996).
Results
All o f t h e d we llin gs we re b u ilt o f n o n p e r m a -n e -n t m a t e r ia ls, m o st ly m u d a -n d wa t t le (82%) wit h va r io u s o p e n in gs t h ro u gh wh ic h b a t s co u ld e a sily e n t e r. Th e h o m e s la cke d r u n n in g wa ter a n d sewa ge d isp o sa l. No n e o f th e h o u ses we re c o n n e c t e d t o t h e e le c t r ic u t ilit y syst e m , b u t a fe w h a d t h e ir own e le ct ric p owe r su p p ly. Th e a ve ra ge h o u se h o ld size wa s 4.26 p e r so n s
a n d t h e a ve ra ge re sid e n c e t im e in Min a Nova wa s 2.7 ye a rs. Fo rt y p e rce n t o f t h e h o u se h o ld s ra ised p igs a n d severa l o f th em a lso ra ised o th er a n im a ls su ch a s p ou ltry a n d goa ts. Th ese a n -im a ls a re a c o m m o n fe e d in g so u rc e fo r D. ro-t u n d u s (Gre e n h a ll, 1988). It wa s re p o r t e d t h a t 66.7% o f t h e se a n im a ls h a d b e e n a t t a c ke d b y b a t s. Se ve n t y o n e p e rc e n t o f t h e q u e st io n -n a ires ob ta i-n ed were from a d u lts (over 14 yea rs o f a ge ) a n d 65.9% we re m e n , m o st o f wh o m were go ld p ro sp ecto rs (98%). Ha lf o f th e p o p u -la t io n o ld e r t h a n 7 ye a r s o f a ge wa s lit e ra t e. Mo st o f t h e p o p u la t io n (86.8%) sle p t in h a m -m o c ks a n d fe w (25.8%) u se d -m o sq u it o n e t s. Mo st (83.3%) o f t h e p o p u la t io n d id n o t kn ow wh ich d isea ses cou ld b e tra n sm itted by b a ts.
Ne a r ly h a lf (41.1%) o f t h e p o p u la t io n h a d b een b itten by b a ts in Min a Nova , a n d 23.3% of t h e a t t a c ks h a d o c c u r re d in t h e p re vio u s 12 m o n th s (7.8% in th e p revio u s m o n th ). An a ver-a ge o f 2.8 ver-a t t ver-a c ks (rver-a n gin g fro m o n e ver-a t t ver-a c k t o 12) wa s fou n d p er p erson a tta cked in th e p revi-o u s 12 m revi-o n th s. Th e va st m a jrevi-o rity revi-o f b ite s we re lo c a t e d o n t h e lowe r lim b s (92.45%). Ab o u t a t h ird (34.1%) o f t h e in d ivid u a ls wh o h a d b e e n b itte n h a d re ce ive d so m e fo rm o f p re ve n ta tive tre a tm e n t fo r ra b ie s, a n d 75.9% o f in te r vie we d a d u lt s st a t e d t h a t t h e y wo u ld p re fe r p re e xp o -su re ra th er th a n p ost-exp o-su re trea tm en t.
In a b iva r ia t e a n a lysis co n sid e r in g h ist o r y o f b a t b it e a s a ye s/ n o fa ct o r, sign ifica n t va r i-a b le s in c lu d e d : ge n d e r, wit h t h e r isk b e in g gre a t e r fo r m a le s (OR = 2.48, CI: 1.14-5.41; p = 0.017); a ge, wit h t h e r isk b e in g gre a t e r fo r a d u lts (OR = 4.14; CI: 1.68-10.18; p = 0.02), a n d n o t u sin g a m o sq u it o n e t (OR = 2.81; CI: 1.17-6.73; p = 0.016) ( Ta b le 1).
ifi-c a n t a sso ifi-c ia t io n fo r a n OR b e low 2.5, b u t t h e a n a lysis su gge st e d a t e n d e n cy fo r m a le s t o b e a t grea ter risk of b a t b ites.
Acco rd in g to th e clu ste r a n a lysis b y h o u se -h o ld , 74.29% -h a d o n e o r m o re m e m b e r t -h a t h a d b e e n a tta cke d b y b a ts in Min a Nova . In a ll h o u se h o ld s in Min a Nova t h a t re p o r t e d a n i-m a ls h a vin g b e e n a t t a cke d b y b a t s, i-m o re t h a n 50% o f t h e p e o p le h a d b e e n b it t e n b y b a t s. In -clu d in g t h e in fo r m a t io n o n t h o se h o u se h o ld s wit h a n a t t a c ke d a n im a l (ye s o r n o ), a n OR o f 15 wa s fo u n d , b u t t h e sm a ll n u m b e r o f h o u se -h o ld s resu lted in a ve r y wid e co n fid en ce in ter-va l (CI: 0.70- 709.89, p = 0.1026, Fish e r’s e xa c t t e st ). Th e re fo re, a h ist o r y o f b it t e n d o m e st ic a n im a ls in t h e h o u se h o ld t e n d e d t o b e a r isk fa c t o r fo r b a t b it e s in h u m a n , b u t t h e re su lt s were n ot sta tistica lly sign ifica n t.
No c t u r n a l c a p t u re o f b a t s yie ld e d n in e D. rotu n d u s(E. Geo ffroy, 1810) a n d th ree fru givo -ro u s b a t s – 2 Ca rollia p ersp icilla t a(Lin n a e u s, 1758) a n d 1 Derm an u ra cin erea (Gerva is, 1856) – wh ich a ll tested n ega tive fo r ra b ies a s exp ect-e d , sin c ect-e t h ect-e rect-e wa s n o ect-e p id ect-e m io lo gic a l ect-e vi-d en ce o f th e viru s circu la tin g in th e a rea a t th e tim e of th e stu d y (Sch n eid er et a l., 1996).
Discussion
Min a Nova sh owe d a h igh ra t e (41.1%) o f a t ta cks on p eop le by com m on va m p ire b a ts, con -st it u t in g o n e a m o n g m a n y h e a lt h h a za rd s fo r t h e villa ge. Th e p e rc e n t a ge o f p e o p le b it t e n ove r t h e t we lve m o n t h s p r io r t o t h e st u d y (23.3%) in Min a Nova wa s c o m p a ra b le t o t h e 22% a n d 27% o f p e o p le b it t e n b y b a t s d u r in g ra b ie s o u t b re a ks re p o r t e d in t h e lit e ra t u re fo r Be lize (Ma c Ca r t h y, 1989) a n d Pe r u (Ló p e z e t a l., 1992), resp ectively.
Th e h ou ses su rveyed in Min a Nova are q u ite vu ln e ra b le t o e n t ra n c e o f b a t s, sin c e t h e y a re b u ilt in sim p le fa sh ion with loca l m a teria ls, i.e., m u d a n d wa ttle wa lls a n d th a tch e d ro o fs, with m a n y o p e n in gs, b o t h t o ke e p t h e c o st d own a n d t o m a ke t h e m c o o le r in t h e h o t c lim a t e. Mo st p e o p le sle e p in h a m m o cks with o u t m o s-q u it o n e t s. Th e m e n a re ge n e ra lly e xh a u st e d fro m th e h a rd p h ysica l la b o r o f m in in g, a n d a l-c o h o l l-c o n su m p t io n t e n d s t o b e h e a vy, t h u s m a kin g th em ea sy p rey for b a ts.
Accord in g to th e m u ltivariate an alysis, a d u lts a re m o re like ly t o b e a t t a cke d . Ma le s m a y a lso b e a t grea ter risk th a n fem a les, a lth o u gh in th e m u ltiva ria te a n a lysis th e effect wa s n ot sta tisti-ca lly sign ifitisti-ca n t . By co n t ra st , in fa r m in g a re a s o f Bra zil, b a t t ra n sm it t e d ra b ie s is m o re co m -m o n in ch ild ren th a n a d u lts (Sch n eid er, 1991). It h a s b een su ggested th a t sin ce th ere a re fewer ch ild re n in go ld m in in g a re a s, th e y a re p ro b a -b ly less a ffected (Sch n eid er et a l., 1996).
In Min a Nova , t h e m o st re c e n t b it e s we re m ostly on th e lower lim b s (92%), m a in ly on th e fe e t . In a n o t h e r o u t b re a k o f b a t b it e s in Bra zil (Co st a e t a l., 1993), m o st (83%) o f t h e a t t a c ks we re a lso lim it e d t o t h e lowe r lim b s, b u t t h e sle e p in g h a b its o f th e victim s we re n o t re p o rt-e d . Howrt-e vrt-e r, a m o n g b a t - t ra n sm it t rt-e d ra b irt-e s c a se s re p o r t e d in t h e p a st d e c a d e in Bra zil (Sch n eid er, 1991), on ly 35% of b ites were loca te d o n t h te lowte r lim b s. H a lf o f t h te ste c a ste s in -vo lve d ch ild re n a n d t o o k p la ce in r u ra l a re a s. In th e rep ort on th e ou tb rea k in Ma d re d e Dios, Pe r u (Ló p e z, 1991), t h e p e rce n t a ge o f b it e s o n t h e lowe r lim b s wa s sligh t ly lowe r (67%) t h a n in Min a Nova , b u t t h e a u t h o r a lso m e n t io n s t h a t n igh t s a re c o ld in Pe r u , wh ic h c o u ld re -q u ire p eo p le to cover u p m o re ca refu lly d u rin g sle e p . In t h e o u t b re a k t h a t o c c u r re d in t h e Am a zon region of Peru (Lóp ez et a l., 1992), 73% o f th e a tta cks wa s o n th e h e a d , wh ile fe e t we re b it t e n o n ly 14% o f t h e t im e ; h owe ve r, t h e re p o r t o ffe r s n o clim a t ic in fo r m a t io n o n t h e re -gio n . It is likely, in fa ct, th a t th e p o sitio n o f th e b it e m a y b e a sso cia t e d wit h clim a t e, sle e p in g h a b its, a n d victim’s a ge.
Tab le 1
Numb e r o f p e o p le surve ye d , numb e r o f p e o p le b itte n, o d d s ratio , and c o nfid e nc e
inte rval. Mina No va, Maranhão State , Brazil.
Variable Surveyed Bitten O R CI
Gender
Fe male 44 12 (27% )
Male 85 41 (48% ) 2.48 1.14-5.41
Age
Child re n 36 7 (19% )
Ad ults 92 46 (50% ) 4.14 1.68-10.18
Use mosquito nets
Ye s 33 8 (24% )
No 95 45 (47% ) 2.81 1.17-6.73
Literate
Ye s 53 23 (43% )
No 49 27 (55% ) 1.60 0.74-3.48
Knowledge of rabies
Ye s 13 7 (54% )
Resea rch is a lso n eed ed to eva lu a te th e risk fa cto r o f livin g in a h o u seh o ld wh o se d o m estic a n im a ls a re b ein g a tta cked by b a ts. Th ese fin d -in gs h a ve a p la u sib le b iologica l b a sis, s-in ce it is kn own t h a t va m p ire b a t s re t u rn t o fe e d o n t h e sa m e vict im m o re t h a n o n ce. If t h e u su a l vic-t im is n o vic-t re a d ily a va ila b le, vic-t h e b a vic-t s m a y vic-t u r n to oth er p rey, p ossib ly h u m a n s.
Th e Bra zilia n Min ist r y o f He a lt h re c o m m en d s p o stexp o su re trea tm en t fo r a ll in d ivid -u a ls a t t a cke d b y b a t s (FN S, 1994). Howe ve r, it is im p o r t a n t t o co n sid e r a cce ss t o t h e va ccin e in re m o t e a re a s, fa r fro m p u b lic h e a lt h se r -vic e s. In t h is st u d y, o n ly 34.1% o f t h e p e o p le wh o h a d b e e n a t t a cke d h a d re ce ive d p o st - e x-p o su re trea tm en t. Th is x-p ercen ta ge is q u ite low, su gge st in g a se r io u s r isk o f a h u m a n ra b ie s o u tb re a k if th e viru s we re circu la tin g in th e re -gio n . Th e stu d y su gge sts th a t go ld p ro sp e cto rs a re a t a h igh e r r isk t h a n t h e ir fa m ilie s, sin c e th ey wo rk a ll d a y in th e garim p os, a n d it wo u ld b e d ifficu lt fo r t h e m t o t ra ve l t o a n o t h e r t own t o ge t a n t i- ra b ie s t re a t m e n t . It wo u ld t h u s b e re le va n t t o co n sid e r p re e xp o su re ra b ie s p re -ve n tio n in a re a s with fre q u e n t b a t a tta cks, circu la t in g ra b ie s vir u s, a n d n o lo ca l h e a lt h se r -vices. Su ch a p ro p o sa l wa s well received b y th e p e o p le in t e r vie we d . Sin c e ra b ie s h a s a n e a r ly 100% m o rta lity ra te, it wo u ld b e u sefu l to b u ild a m a t h e m a t ica l m o d e l t o e va lu a t e a ll p o ssib le co n t ro l a ct io n s fo r h u m a n ra b ie s t ra n sm it t e d by va m p ire b a ts.
An o t h e r p o t e n t ia l m e a su re wo u ld b e t o con trol th e va m p ire b a t p op u la tion . Th is wou ld h a ve t o b e ca rr ie d o u t b y sp e cia list s, so a s n o t to en d a n ger th e o th er sp ecies o f b a ts in th e re-gio n . Ot h e r a c t io n s sh o u ld a im a t p re ve n t in g a tta cks, su ch a s ed u ca tio n a l wo rk en co u ra gin g th e u se o f p ro te ctive d e vice s. Sin ce fe w p e o p le u sed m o sq u ito n ets, th eir im p o rta n ce a s a p ro -tective fa cto r in th e m u ltiva ria te a n a lysis co u ld n o t b e a scerta in ed . An o th er stu d y with a la rger sa m p le sh ou ld th u s b e p erform ed .
Ap a r t fro m b a t a t t a c ks, t h e re a re va r io u s o t h e r h e a lt h p ro b le m s in t h e st u d y a re a , su ch a s e xp o su re t o m e rc u r y u se d t o e xt ra c t go ld ,
Plasm odiu m falcip aru mm alaria, sexu ally tra n s-m itte d d ise a se s, cu ta n e o u s le ish s-m a n ia sis, a n d wid e sp re a d a ct s o f vio le n ce. No r m a lly t h e re is ju st o n e ge n e ra l p ra c t it io n e r lo c a t e d in t h e co u n t y, b u t a t t h e t im e o f t h is st u d y t h e re wa s n o p h ysicia n a t a ll. Go ld p ro sp e ct o rs wo rk o n average 10 h ou rs a d ay an d as m u ch as 24 h ou rs a d a y in so m e ga rim p os. Wo rke r s a re p a id a c -c o rd in g t o t h e a m o u n t o f go ld t h e y fin d , a n d d u r in g t h e t h re e - m o n t h ra in y se a so n t h e y a re o u t o f wo rk, so t h e re is a se a so n a l e xo d u s o f so m e 35% o f th e Min a Nova p o p u la ce. An y d e -c isio n s a b o u t ra b ie s -c o n t ro l m u st -c o n sid e r a b ro a d e r c o n t e xt o f h e a lt h a n d o c c u p a t io n a l con d ition s.
At t a cks b y h e m a t o p h a go u s b a t s o n p e o p le wit h t h e r isk o f ra b ie s t ra n sm issio n h a ve b e e n a p rob lem in La tin Am erica for cen tu ries. In re-ce n t d e ca d e s re p o r t s o f b a t a t t a cks o n p e o p le a n d ca se s o f h u m a n ra b ie s t ra n sm it t e d b y t h e com m on va m p ire b a t h a ve in crea sed , esp ecia l-ly in th e Am a zon region of Peru a n d Bra zil. Sev-e ra l o f th Sev-e sSev-e o u tb rSev-e a ks h a vSev-e b Sev-e Sev-e n p rSev-e cSev-e d Sev-e d b y so m e ch a n ge in t h e lo ca l p ro d u ct io n p ro ce ss, su c h a s t h e su d d e n re m ova l o f d o m e st ic a n i-m a ls a s a fo o d so u rce, go ld p ro sp ectin g, o r d e-fo re st a t io n , p ro ce sse s t h a t wo u ld h a ve a lt e re d t h e e c o syst e m in wh ic h t h e D. rot u n d u sfo r -m e r ly live d . En viro n -m e n t a l c h a n ge s in t h e se a re a s p ro b a b ly re su lt in m o re va m p ire b a t a t -ta cks on h u m a n s.
Th e re fo re, t h e re sh o u ld a lso b e m o re re se a rch o n h ow go ld m in in g in t h e Am a zo n re -gion p laces p eop le an d th e en viron m en t at risk. Hu m a n in va sio n o f p re se r ve d a re a s fo r go ld m in in g wit h re su lt in g la n d slid e s, u se o f n o isy m a ch in er y, h u n tin g o f wild ga m e fo r fo o d , a n d o th er fo rm s o f a ggressio n a ga in st n a tu re p ro b -a b ly c-a u se -a n im b -a l-a n ce in th e n -a tu r-a l eco sys-t e m . Su c h e xp lo isys-t a sys-t io n o f n a sys-t u re a p p e a r s sys-t o p la ce b o th cu rren t in h a b ita n ts a n d fu tu re gen -era tion s a t risk.
Acknowledgments
References
ALMANSA, J. C. & GARCIA, R. C., 1980. In cid en cia d el
m u rcié la go h e m a t ó fa go Desm od u s rot u n d u sso
-b re lo s in d íge n a s Ya n o m a m i d e Ve n e zu e la .
Do-n aDo-n a Acta Vertebrata, 7:113-117.
ALVAREZ, E., 1997. Ra b ia t ra n sm it id a p o r va m p iro s:
Dist r ib u ció n , fre cu e n cia e im p o r t a n cia . Técn ica
Pecu aria en M éxico, 35:93-104.
BAER, G. M., 1982. Ra b ia b ovin a p a ra lítica y ra b ia e n
e l m u rcié la go va m p iro. In : Historia N atu ral d e la
Rabia(G. M. Ba er, org.), p p. 63-83, México, DF: La Pren sa Méd ica Mexica n a .
COSTA, M. B.; BONITO, R. F. & NISHIOKA, S. A., 1993. An o u t b re a k o f va m p ire b a t b it e s in a Bra zilia n
villa ge. Trop ica l M ed icin e a n d Pa ra sit ology, 44:
219-220.
CONSTANTINE, D. G., 1988. Tra n sm issio n o f p a t h o
-ge n ic m icro o rga n ism s b y va m p ire b a t s. In : N a t
-u ral History of Vam p ire Bats(A. M. Green h a ll & U. Sch m id t, ed .), p p. 167-189, Boca Raton : CRC Press.
FN S (Fu n d a ç ã o Na c io n a l d e Sa ú d e ), 1994. N orm a s
Técn icas d e Tratam en to Preven tivo Con tra a Rai-va Hu m an a. Bra sília : Min istério d a Sa ú d e.
GREENH ALL, A. M., 1988. Fe e d in g b e h a vio r. In : N
at-u ral History of Vam p ire Bats (A. M. Gre e h a ll & U . Sch m id t, ed .), p p. 111-131, Boca Raton : CRC Press. INPPAZ (Pa n -Am e rica n In stitu te fo r Fo o d Pro te ctio n
a n d Zo o n o se s), 1997. Region a l In form a t ion on
Rabies in t h e Am ericas. INPPAZ in t h e Am e r ica s, 5. Bu e n o s Aire s: Pa n Am e rica n He a lth Orga n iza -tion .
LOPEZ, A., 1991. Presen tación d el Brote Ep id ém ico d e
Ch oq u e, M a d re d e Dios (Perú ). Re u n ió n d e c o n -su lt a so b re la a t e n ció n a p e rso n a s e xp u e st a s a la ra b ia tra n sm itid a p o r va m p iro s. Wa sh in gto n , DC: Orga n iza ción Pa n a m erica n a d e Sa lu d .
LOPEZ, A.; MIRANDA, P.; TEJADA, E. & FISH BEIN, D., 1992. Ou t b re a k o f h u m a n ra b ie s in t h e Pe r u via n
ju n gle. Lan cet, 339:408-412.
LORD, R. D.; FU EN ZALID A, E.; D ELPIETRO, H .; LARGH I, O. P.; D IAZ, A. M . & LAZARO, L., 1975. Ob serva tion s on th e ep izootiology of va m p ire b a t
ra b ies. Bu lletin of th e Pan Am erican Health
Orga-n iz atioOrga-n, 9:189-195.
Ma cCARTH Y, T., 1989. Hu m a n d e p re d a t io n b y va m
-p ire b a t s (Desm od u s rot u n d u s) fo llowin g a h o g
ch o le ra ca m p a ign . Am erica n Jou rn a l of Trop ica l
Med icin e an d Hygien e, 40:320-322.
SCH NEIDER, M. C., 1991. Presen tación d el Brote Ep
i-d ém ico i-d e Ap iacas, M ato Grosso (Brasil). Reu n ió n d e co n su lta so b re la a ten ció n a p erso n a s exp u es-ta s a la ra b ia tra n sm itid a p o r va m p iro s. Wa sh in g-ton , DC: Organ ización Pan am erican a d e Salu d . SCH NEIDER, M. C. & SANTOS-BU RGOA, C. S., 1995.
Algu n a s co n sid e ra cio n e s so b re la ra b ia h u m a n a
tra n sm itid a p or m u rciéla go. Salu d Pú blica d e M
é-xico, 37:354-362.
SCH NEIDER, M. C.; SANTOS-BU RGOA, C.; ARON, J.; M U N OZ, B.; RU IZ- VELAZCO, S. & U IED A, W., 1996. Poten tia l force of in fection of h u m a n ra b ies t ra n sm it t e d b y va m p ire b a t s in t h e Am a zo n ia n
re gio n o f Bra zil. Am erica n Jou rn a l of Trop ica l
Med icin e an d Hygien e, 55:680-684.
STATA CORPORATION , 1997. St a t a St a t ist ica l Soft
-w are. Release 5.0. Co lle ge Sta tio n : Sta ta Co rp o ra -tion .
TAMSITT, J. R. & VALDIVIESO, D., 1970. Los m u rciéla -go s y la sa lu d p ú b lica : Estu d io co n esp ecia l
refer-e n c ia a Pu refer-e r t o Ric o. Bolet ín d e la Oficin a Sa n
i-taria Pan am erican a, 69:122-140.
U IED A, W., 1989. Sa n gu ivo r ia e m m o rc e go s. In : VII
En co n t ro An u a l d e Et o lo gia , An a is, p p . 150- 161.
Botu ca tu : Un iversid a d e Esta d u a l Pa u lista . U IEDA, W.; H AYASH I, M. M.; GOMES, L. H . & SILVA,
M. M. S., 1996. Esp é cie s d e q u iró p te ro s d ia gn o
s-t ica d a s co m ra iva n o Bra sil. Bolet im d o In st it u t o
Pasteu r, 1:17-36.
VERTEU IL, E. & U RICH , F. W., 1935. Th e st u d y a n d co n t ro l o f p a ra lyt ic ra b ie s t ra n sm it t e d b y b a t s in
Trin id ad , British West In d ies. Royal Society of Trop
