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Since 1999, human infection caused by Orthopoxvirus has been observed in at least eight Brazilian states, with the presence of vesicles that evolve to pustules and crusts, especially on the hands, arms and face, after contact with cows showing comparable lesions on the udder. In addition to the skin lesions, there have been descriptions of patients with axillary ganglionic reactions that are sometimes painful, along with fever, headache, fatigue, dehydration, anorexia, sudoresis, arthralgia and muscle pain. The condition evolves over a three to four-week period. Vulvar lesions and transmission within families have also been described. Molecular studies have shown that the poxviruses identified are genetically related to vaccinia virus samples that were used in vaccination campaigns in the past. Clinical specimens from 80 human infections were studied in the laboratory, and orthopoxvirus infections were confirmed in 68 cases. The lesions observed in these patients are presented and the implications of this zoonosis in Brazil are discussed. Key-words:Orthopoxvirus. Vaccinia-like viruses. Human infections. Brazil.No Brasil, as campanhas de vacinação foram realizadas nas zonas rurais por equipes que se deslocavam de uma propriedade à outra, manipulando os frascos contendo a vacina viva com o vírus vaccinia em altos títulos, sendo comum a não eliminação adequada dos materiais residuais, contendo restos do imunizante. Admite-se que estes procedimentos permitiram a implantação de amostras do vírus vaccinia em ciclos naturais, pela infecção de animais reservatórios, como roedores silvestres, vindo a atingir posteriormente bovinos e pessoas que manejam estes animais. Um laboratório para o estudo destas infecções foi montado no Instituto Oswaldo Cruz, descrevendo-se neste artigo a experiência obtida no estudo de casos humanos ao longo dos últimos 10 anos.

In the present study we investigated the presence of infections by vaccinia-like viruses in dairy cattle from 12 counties in the state of Rio de Janeiro in the last 9 years. Clinical specimens were collected from adult animals with vesicular/pustular lesions mainly in the udder and teats, and from calves with lesions around the nose and mouth. A plaque reduction neutralization test (PRNT) was applied to search for antibodies to Orthopoxvirus; the vesicular/pustular fluids and scabs were examined by PCR, electron microscopy (EM) and by inoculation in VERO cells for virus isolation. Antibodies to Orthopoxvirus were detected in most cases. The PCR test indicated a high nucleotide homology among the isolates and the vaccinia viruses (VACV) used as controls. By EM, typical orthopoxvirus particles were observed in some specimens. The agents isolated in tissue culture were confirmed as vaccinia-like viruses by EM and PCR. The HA gene of the vaccinia-like Cantagalo/IOC virus isolated in our laboratory was sequenced and compared with other vaccinia-like isolates, showing high homology with the original Cantagalo strain, both strains isolated in 1999 from dairy cattle. Antibodies to Orthopoxvirus were detected in one wild rodent (genus Akodon sp.) collected in the northwestern region of the state, indicating the circulation of poxvirus in this area. Nonetheless, PCR applied to tissue samples collected from the wild rodents were negative. Vesicular/pustular lesions in people in close contact with animals have been also recorded. Thus, the vaccinia-like virus infections in cattle and humans in the state seem to be an expanding condition, resulting in economic losses to dairy herds and leading to transient incapacitating human disease. Therefore, a possible immunization of the dairy cattle in the state should be carefully evaluated.

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ABSTRACT

Leptospirosis is a zoonotic disease of world importance, and its transmission depends on the interaction between humans and animals. Given the necessity to investigate potential hosts of Leptospira spp., this study verified the prevalence of different serovars in the species of Rhipidomys spp., a widespread sigmodont rodent in Brazil. The studied population originates from a semi-evergreen forest located in the county of Uberlândia, in the state of Minas Gerais. The microscopic agglutination test (MAT) was performed with 14 serovars. Thirteen out of the 43 wild rodents captured showed a positive agglutination reaction, with a greater prevalence of the serovars Pyrogenes, Copenhageni, and Canicola. This study found a prevalence of 30.3% anti-Leptospira spp. antibodies; all positive animals were reactive to more than one serovar.

Th e incidence of poxvirosis, a zoonosis caused by viruses of the family Poxviridae, has increased over the past two decades in Brazil. Th e important features of the Orthopoxvirus infection include rapid spread, occurrence restricted to lactating cows, lack of hygiene, person-to-person spread, and occurrence at properties where milking is conducted. We detected the presence of vaccinia virus antibodies, specifi cally for Cantagalo virus, in samples from two distinct populations from the state of Rio de Janeiro: (i) healthy professionals who live in the State of Rio de Janeiro and handle animals and (ii) in patients with cutaneous lesions compatible with poxvirosis. Th e plaque reduction neutralisation test (PRNT) was used. Of the 136 samples from the group of healthy professionals, 12 displayed seroreactivity with titres lower than or equal to 1/10. Anti-poxvirus antibodies were detected in 68.3% of samples of patients suspected to be infected with poxvirus (28/41). Th erefore, the plaque reduction neutralisation test constitutes a sensitive assay that can be more commonly used for diagnosis. Furthermore, professionals who handle animals should be included as an occupational risk group in areas with confi rmed human poxvirus cases.