Genomic diversity of vaccinia virus strain Cantagalo isolated in southeastern Brazil during the early years of the outbreak, 1999-2006

Outbreaks of a vesiculopustular disease in dairy cattle and milkers have been frequently reported in Brazil since 1999 when the vaccinia virus strain Cantagalo was first isolated in the State of Rio de Janeiro. However, the genomic diversity of the viral isolates associated with these outbreaks is not well known, particularly in the southeastern states that represent the focal point of virus spread to other regions. Here, we report the genomic sequences and an analysis of the polymorphic site profiles and genotypic diversity of four clinical isolates of vaccinia virus strain Cantagalo collected from 1999 to 2006 in southeastern Brazil.

Clinical signs, diagnosis, and case reports of Vaccinia virus infections

Vaccinia virus is responsible for a zoonosis that usually affects cattle and human beings in Brazil. The initial clinical signs of the infection are focal red skin areas, fever, and general symptoms similar to those of a cold. Then, pustules and ulcerated lesions surrounded by edema and erythema follow, as well as local lymphadenopathy that can last for weeks. Cure and healing of the lesions occur over several weeks, leaving a typical scar in the skin of people and animals affected. The infection definitive diagnosis is made through morphological characterization of the virus by use of electron microscopy, followed by PCR for specific viral genes. Since 1963, circulating orthopoxviruses in infectious outbreaks in several regions of Brazil have been reported. Later, the etiological agent of those infections was characterized as samples of Vaccinia virus. In addition, the widespread use of those viruses in research laboratories and mass vaccination of militaries have contributed to increase the cases of those infections worldwide. Thus, several epidemiological and clinical studies are required, as well as studies of viral immunology, public health, and economic impact, because little is known about those Vaccinia virus outbreaks in Brazil.