R e v ista d a S o cie d a d e B ra sile ira d e M ed ic in a T ro p ica l 2 7 (1 ):1 5 -1 8 , j a n -m a r , 1994.
P IG B IT E I N B R A Z IL : A C A S E S E R IE S F R O M A T E A C H I N G H O S P I T A L
S érg io de A n dra de N ish io k a , S u za na T erum i H a n d a a nd R a q u el S o u za N u nes
A retrospective su rvey d one fr o m 1 9 8 7 till 1990 revea led th at 23 p a tie n ts bitten by p ig s so u g h t m ed ica l help a t a teaching h o sp ita l in U berlândia, in so u th ea stern B razil. M o st ca ses (21) w ere fr o m U berlândia. The cases were evenly d istrib u ted by m onth a n d by y e a r; m o st o f th em (14/16; 8 7 .5 % ) o cc u rre d betw een 7. OOa.m. a n d 7 .00 p . m. The m ale to fe m a le ratio w as 6 .7:1. A g e ra n g ed fr o m 6 to 73 (mean 3 8 .9 5 _+ SD 2 2 .0 6 , m ed ia n 36). The bites w ere m o re com m on on th e u p p er lim bs, particularly on the fo re a rm s. In 11(47.8% ) ca ses th e injury w as d e sc rib e d as deep. In m ost cases w here inform ation w as available the injury w as related to capture, tra n sp o rt o r im m obilisation o fth e p ig fo r slaughter. The fo llo w in g m ed ica l p ro c e d u re s w ere p e rfo rm ed : lo cal cleansing in 19(82.6% ) cases, rabies vaccine (12; 5 2 .2 % ), antirabies se ru m (2; 8 .7 % ), su tu rin g (6; 2 6 .1 % ) a n d teta nus vaccine (12; 52.2% ). There w as no ca se o f infectio n a t the bite site, neither o f rabies o r tetanus. B y o u r data , th e a n n u a l incidence o f p ig bite in U berlândia can be estim ated to be ab o u t 1.5/100.000.
K ey-w ords: Bites. Injuries. R abies. Swine.
Little has been published in the literature on injuries caused by swine in man. Barss & Ennis2 reviewed 20 cases seen at a reference hospital in Papua New Guinea, w here 65 % o f the patients were bitten or gored by feral pigs. Provoked and unprovoked injuries by domestic pigs have been reported both in developed1 7 11 and developing countries8. M ost o f these studies are case reports o f surgical aspects and infectious complications, with little emphasis on epidemiological aspects.
W e report a retrospective survey of cases of pig bite seen in four years at a teaching hospital in : southeastern Brazil. W e know o f no study on pig s bite carried out previously in Brazil.
I M A TERIA L AND METHODS
i
! The medical records o f patients bitten by pigs | who sought medical help at the teaching hospital o f i theFederal University ofUberlândia, in southeastern t B raz il, fro m 1987 to 1990 w e re su rv ey ed
retrospectively. The distribution o f the cases in time and space, by age, sex, clinical findings and treatment measures w ere recorded. Attempts to
C entro de C iências Biomédicas, Universidade Federal de U berlândia, U berlândia, M G , Brasil.
A d d re ss to: D r. Sérgio de Andrade Níshioka. Av. T eresina 1415, U m uaram a, 38405-384 U berlândia, M G , Brasil. Recebido para publicação em 28/10/93.
obtain more detailed inform ation w ere made by visiting the households o f the patients living in urban Uberlândia and interview ing them or their relatives. This was achieved for 7 cases.
RESULTS
Among the 23 patients victims o f pig bite attended in the 4-year study period, 21 w ere from Uberlândia. The cases were evenly distributed by month and by year; most o f them (14/16; 87.5% ) occurred between 7.00 a.m . and 7.0 0 p.m . The male to female ratio was 6 .7 to 1. Age ranged from 6 to 73 years, with a mean o f 38.95 + SD 22.06 and a median o f 36 (Figure 1). T he bites w ere more common in the upper than in the lower limbs, and most of them were on the forearms (Table 1). The injury was described as deep (as opposed to superficial) in 12 out o f the 23 cases.
Inform ation on activity o f the victim at the time o f the injury was available for only 9 cases, and in 7 o f them it was related to capture, transport or im mobilisation o f the pig for slaughter. In one case the victim was cleaning the pigpen and in another a child was “playing” w ith the pig. Among the 7 victims interviewed lately, all inform ed that the pigs belonged to them, their neighbours or employer, and 5 referred that the pigs w ere raised in pens. Tw o o f the interviewed patients had a past history o f pig
N ish io k a S A , H a n d a S T , N u n e s R S . P ig b ite in B ra zil: a c a se s e r ie s fr o m a te a c h in g h o sp ita l. R e v is ta d a S o cie d a d e B ra s ile ir a d e M e d ic in a T ro p ic a l 2 7 :1 5 -1 8 , ja n - m a r , 1994.
T a b le 1 - D is tr ib u tio n o f th e c a s e s o f b ite a tte n d in g the te a ch in g h o s p ita l (U b e rlâ n d ia , 1 9 8 7 -1 9 9 0 ), b y s ite o f th e b ite * .
Site of the bite N° %
Upper limb (subtotal) 16 61.5
finger 3 11.5
hand 1 3.8
forearm 10 38.5
arm 1 3.8
unspecified 1 3.8
Lower limb (subtotal) 8 30.8
foot 1 3.8
leg 3 11.5
knee 1 3.8
thigh 3 11.5
Unspecified 2 7.7
26 100.0
* One patient was bitten on 2 and another on 3 different sites
bite.
T he fo llo w in g procedures carried out for treatment o f the patients w ere cited in the review ed charts: local cleansing (19; 82.6% cases), rabies vaccine (12; 5 2 .2% ), antirabies serum (2; 8 .7% ), suturing (6; 26.1% ) and tetanus vaccine (12; 52.2% ). N o patient referred infection o f the bite site. There w as also no case o f rabies or tetanus in the victim s o f p ig bite.
D ISC U SSIO N
R aising pigs is an important econom ic activity in many parts o f the w orld. F or instance, there are estimates o f m ore than 55 m illion p ig s in the U nited States7, and 33 m illion in Brazil4. A n unknown number is raised for fo o d or as a complem entary source o f incom e by poor people, particularly in rural areas but also in suburbs o f tow ns and cities o f
N ish io ka S A , H a n d a ST , N u n e s R S . P ig b ite in B ra zil: a ca se s e r ie s fr o m a tea ch in g h o sp ita l. R e v ista d a S o c ie d a d e B ra sile ira d e M e d ic in a T ro p ica l 2 7 :1 5 -1 8 , ja n -m a r , 1994.
developing countries. There, pigs are frequently raised w ithout pigpens, and sometimes have free access into the hom e8. W hether this increases the risk o f diseases associated with poor hygiene, it also creates o p p o rtu n itie s for bites in m an. Particularly children with food or food remnants in their hands and fa ce are at risk o f being injured by hungry unpenned pigs2 8.
A nother group at risk o f pig bite are adults who raise pigs dom estically o r who are in contact with these animals occupationally, like abattoir workers. Although w e could interview only a fraction o f our patients, most o f them w ere bitten when catching, carrying o r im m obilising pigs, practices related to domestic slaughtering, carried out by people relying mostly on their experience to prevent bites. These activities are ascribed preferentially to men, as can be shown by the high male to female ratio in this series. Slaughtering in abattoirs is theoretically safer, as the employees have less direct contact with the swine.
It was an interesting finding the fact that the forearm s were the most common site o f bite, probably because these are the most exposed area when one is trying to im mobilise a pig. Although m ost o f our patients referred deep wounds, which is confirmed by the fact that in more than 25 % o f them suturing was required, their recovery was uneventful. Pig bites have been associated with severe lesions, but that particularly in children and victims o f feral pigs2 8. From the literature, infection o f the bite site should be an expected complication o f injuries caused by pigs, because the mouths of these anim als, particularly the unpenned ones, are heavily contam inated, infections by haemolytic streptococci, P a s t e u r e l l a , B a c t e r o i d e s , P r o t e u s , E .
c o l i1 and F l a v o b a c t e r i u m 1 have been described.
The absence o f infection in our patients is somewhat surprising, and can be explained mainly because of adequate irrig; tion and care o f the wound. Our finding does not sup p o rt the routine use o f prophylactic antim icrobials following pig bite, as suggested by B am ham 1.
Hum an rabies is endemic in Brazil, w here an average o f 83 cases w ere reported annually from 1980 to 1991 to the M inistry o f H ealth5. Rabies in pigs is not commonly reported, but rabid swine in
the excitatory phase may bite other pigs, animals and man3 9. The policy o f the Brazilian M inistry o f H ealth is to give rabies vaccine and antirabies serum as prophlaxis following bites in man o f all mammals except dogs, cats and non-selvatic rodents, for w hom there are specific reco m m en d atio ns10. According to these recommendations, all our patients should have received the rabies vaccine and antirabies serum, and that was not done possibly becai..,_ not all physicians w ere informed about the possible association o f pig bite and rabies. Post exposure prophylaxis is debatable if the aggressor pig has no clinical evidence o f rabies and can be observed, because o f the already mentioned fact that rabies in swine is rare. Suturing should be avoided or delayed6 12, but it is sometimes necessary depending on the site and size of the wound.
Tetanus is another possible com plication of injuries caused by pigs, as the contam inated w ounds can be the portal o f entry for C l o s t r i d i u m t e t a n i
spores. M any patients from this study did not receive tetanus prophlaxis, but w e are unable to say why because w e lack informati on about their previous im m unization status. N evertheless, physicians facing victims o f animal bite have a good opportunity to check their patients’ immunization status and to offer them tetanus or the other vaccines they need.
From our data, assuming that all the victim s o f pig bite o f the town were seen at the teaching hospital, the annual incidence o f pig bite in Uberlândia can be estimated to be about 1.5/ 100,000. If w e could extrapolate this figure for the country, that would give us m ore than 2,000 cases per year in Brazil, which certainly is a conservative estimate as many victims do not seek medical assistance. A lthough it is certainly not a priority in public health, more attention should be give in Brazil and other countries to the adequate registration o f cases o f pig bite in humans and guidelines for its management should be developed. In developing countries people are likely to continue to raise and slaughter pigs in their backyards; studies on the technique o f slaughtering in these settings and conditions should be carried out to assess the risks and determine the safest procedures to be perform ed, aiming at providing an effective orientation for the prevention o f pig bite during slaughter.
N ish io k a S A , H a n d a S T , N u n es R S. P ig bite in B ra zil: a c a se se r ie s fr o m a tea ch in g h o sp ita l. R e v ista d a S o cie d a d e B r a s ile ir a d e M e d ic in a T ro p ica l 2 7 :1 5 -1 8 , ja n -m a r , 1994.
R ESUM O
Um le vantam ento re trospectivo revelo u que 23 p a c ie n te s vítim as d e m o rd id a d e p o r c o p ro cu ra ra m a ssistên cia m éd ic a n u m h ospital-escola em U berlândia, B ra sil, d e 1 9 8 7 a 1990. A m aioria dos p a cien te s (21) p r o c e d ia d e U berlândia. O s ca so s fo r a m distrib uíd os u nifo rm em en te p o r m ês e ano; a m aioria deles (14/16; 8 7 ,5 % ) o co rreu entre à s 7 e às 19 horas. A razão h om em . m u lh e r fo i d e 6,7:1. A idade d o s p a cien tes variou d e 6 a 73 a n o s (m édia: 3 8 ,9 5 +_DP 2 2,06), m ediana 36. A s m o rd id a s fo ra m m ais com uns nos m em bros superiores, p a rtic u la rm e n te n o s antebraços. E m 11(47,8% ) casos o fe r im e n to f o i d escrito co m o p ro fu n d o . Na m aioria dos ca so s em q u e h o u ve inform ação disponível, o fe rim en to f o i rela cio n a d o co m captura, transporte ou im obilização d o su ín o p a r a abate. O s seguin tes p rocedim entos m édicos fo r a m rea liza d o s: lavagem lo c a l em 19 (8 2 ,6 % ) casos, vacin a an ti-rá b ica (12; 5 2 ,2 % ), so ro anti-rábico (2; 8 ,7 % ), su tu ra (6; 2 6 ,1 % ), e vacina antitetâ nica (12; 5 2 ,2 % ). P elos n o sso s d a d o s, a incid ência an u a l de m o rd ed u ra d e p o r c o em U berlândia p o d e s e r estim ada em 1 ,5 /1 0 0 .0 0 0 habitantes.
P a la vra s-ch a ves:L e sõ es. M ordid as. R aiva. Suínos.
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