Achados de necropsia em três casos de toxoplasmose ocorridos naturalmente em macacos-de-cheiro (Saimiri sciureus) obtidos de capturas na região Amazônica foram descritos. A avaliação histopatológica do fígado, baço, rins e linfonodos mesentéricos mostrou múltiplos focos de inflamação e necrose. Cistos morfológicos típicos e bem definidos de Toxoplasma gondii e formas livres foram detectados pelo método da imunoperoxidase com infiltrados inflamatórios. A presença de T. gondii na colônia de primatas estudada pode influenciar severamente os resultados de experimentos realizados nos animais.

Necropsy findings in three cases of naturally occurring toxoplasmosis in squirrel monkeys (Saimiri sciureus) obtained as wild catches from the Amazon region were described. Histopathological evaluation of the liver, spleen, kidneys and mesenteric lymph nodes showed multiple foci of inflammation and necrosis. Typical, well-defined morphologic Toxoplasma gondii cysts and free forms of the parasite were found by immunoperoxidase staining within inflammatory infiltrates. The presence of T. gondii in the studied colony could severely influence the results of experiments performed in the animals.

Campylobacteriosis is an extremely important zoonosis, circulating freely in the environment. In nonhuman primates kept in open facilities and bred for experimental purposes, the presence of Campylobacter spp. could cause severe damage to the production and interfere with the results of scientific research. In this paper, we assessed the circulation of Campylobacter spp. in a colony of clinically healthy rhesus monkeys (Macaca mulatta) destined to research. The analysis was carried out during seven non-consecutive years. Data showed that despite several changes made in animal management along the studied years in order to control this zoonosis, reduction of bacterial charge did not occur. Significant differences among the age groups and sex were observed. Infants showed higher susceptibility than adult animals. In general males were more infected than females. Modifications adopted in the handling techniques need to be reviewed with the intent of improving the production, reducing bacterial infection of the stock and avoiding undesirable cross reactions in the research carried out with these animals. Therefore, this paper alerts professionals that work directly with captive rhesus monkeys about the risks of Campylobacter spp. infection and possible interference on the experimental procedures.

Physiological parameters of laboratory animals used for biomedical research is crucial for following several experimental procedures. With the intent to establish baseline biologic parameters for non-human primates held in closed colonies, hematological and morphometric data of captive monkeys were determined. Data of clinically healthy rhesus macaques (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis), and squirrel monkeys (Saimiri sciureus) were collected over a period of five years. Animals were separated according to sex and divided into five age groups. Hematological data were compared with those in the literature by Student's t test. Discrepancies with significance levels of 0.1, 1 or 5% were found in the hematological studies. Growth curves showed that the sexual dimorphism of rhesus monkeys appeared at an age of four years. In earlier ages, the differences between sexes could not be distinguished (p < 0.05). Sexual dimorphism in both squirrel monkeys and cynomolgus monkeys occurred at an age of about 32 months. Data presented in this paper could be useful for comparative studies using primates under similar conditions.

In order to determine the best type of rabies vaccine to use as a booster, 78 serological samples from singly vaccinated cattle were analyzed by counterimmunoelectrophoresis technique. The animals were divided into several groups, received the first vaccine dose with modified live virus vaccine (ERA strain) and were revaccinated with inactivated virus or modified live virus vaccines. Boosters were given at 2, 4, 8, 12 and 16 weeks following first vaccination. Results showed high titres in the cases of booster with inactivated vaccine. In all cases, however, detectable antibody titres declined quickly.

Visando avaliar a resposta imunológica produzida por vacinas anti-rábicas em primatas não humanos neotropicais, trinta sagüis (Callithrix sp) foram divididos em cinco grupos de seis indivíduos e submetidos a cinco diferentes esquemas de vacinação anti-rábica, utilizando-se duas vacinas animais distintas existentes no mercado. A primeira produzida em cérebro de camundongos lactentes (Fuenzalida e Palacios), e a segunda, em cultura de células NIL-2. Acompanhamento sorológico pós-vacinal foi realizado periodicamente. Os resultados mostraram que a vacina Fuenzalida e Palacios não foi eficaz para a proteção dos animais, utilizando-se uma única dose ou mesmo com o reforço. Porém, os sagüis apresentaram anticorpos detectáveis, ao adotar-se o esquema semelhante ao de pré-exposição indicado para os seres humanos, e apenas um animal contraiu raiva após o desafio viral. Por outro lado, a vacina produzida em cultura de células NIL-2 produziu elevados títulos de anticorpos em todos os animais imunizados e todos os animais resistiram ao desafio viral.

In order to evaluate the immune response produced by rabies vaccines in new world nonhuman primates, thirty marmosets (Callithrix sp) were divided into five groups of six individuals and submitted to five different antirabies vaccination schemes using two distinct commercially available animal vaccines. The first was produced in suckling mouse brain (Fuenzalida and Palacios), and the second in NIL-2 cell culture. Post-vaccine serological monitoring was carried out periodically. The results showed that the Fuenzalida and Palacios vaccine was not able to protect the animals when using a single dose or even with a booster. But when submitted to a vaccination routine similar to that used for humans, the marmosets showed detectable antibodies, and only one succumbed to rabies after being challenged. In addition, the vaccine produced in NIL-2 cell culture induced high antibody levels in all vaccinated animals and all animals survived the viral challenge.