Comparative analysis of Mouse Inoculation Test and Virus Isolation in Cell Culture for rabies diagnosis in animals of Parana, Brazil.

INTRODUCTION: Rabies is an acute zoonotic disease, caused by a rhabdovirus that can affect all mammals, and is commonly transmitted by the bite of a rabid animal. The definitive diagnosis is laboratorial, by the Fluorescent Antibody Test (FAT) as a quick test and Mouse Inoculation Test (MIT) as a confirmatory test (gold standard). Studies conducted over the past three decades indicate that MIT and Virus Isolation in Cell Culture (VICC) can provide the same effectiveness, the latter being considered superior in bioethics and animal welfare. The aim of this study was to compare VICC with MIT, in terms of accuracy, biosafety and occupational health, supply and equipment costs, bioethics and animal welfare, in a Brazilian public health lab. METHODS: We utilized 400 samples of animal neurological tissue to compare the performance of VICC against MIT. The variables analyzed were accuracy, biosafety and occupational health, time spent in performing the tests, supply and equipment costs, bioethics and animal welfare evaluation. RESULTS: Both VICC and MIT had almost the same accuracy (99.8%), although VICC presented fewer risks regarding biosafety and mental health of the technicians, and reduced time between inoculation and obtaining the results (approximately 22 days less). In addition, VICC presented lower supply costs (86.5% less), equipment costs (32.6% less), and the advantage of not using animals. CONCLUSIONS: These results confirm that VICC can replace MIT, offering the same accuracy and better features regarding cost, results, biosafety and occupational health, and bioethics and animal welfare.

Comparative analysis of Mouse Inoculation Test and Virus Isolation in Cell Culture for rabies diagnosis in animals of Parana, Brazil

Abstract INTRODUCTION: Rabies is an acute zoonotic disease, caused by a rhabdovirus that can affect all mammals, and is commonly transmitted by the bite of a rabid animal. The definitive diagnosis is laboratorial, by the Fluorescent Antibody Test (FAT) as a quick test and Mouse Inoculation Test (MIT) as a confirmatory test (gold standard). Studies conducted over the past three decades indicate that MIT and Virus Isolation in Cell Culture (VICC) can provide the same effectiveness, the latter being considered superior in bioethics and animal welfare. The aim of this study was to compare VICC with MIT, in terms of accuracy, biosafety and occupational health, supply and equipment costs, bioethics and animal welfare, in a Brazilian public health lab. METHODS: We utilized 400 samples of animal neurological tissue to compare the performance of VICC against MIT. The variables analyzed were accuracy, biosafety and occupational health, time spent in performing the tests, supply and equipment costs, bioethics and animal welfare evaluation. RESULTS: Both VICC and MIT had almost the same accuracy (99.8%), although VICC presented fewer risks regarding biosafety and mental health of the technicians, and reduced time between inoculation and obtaining the results (approximately 22 days less). In addition, VICC presented lower supply costs (86.5% less), equipment costs (32.6% less), and the advantage of not using animals. CONCLUSIONS: These results confirm that VICC can replace MIT, offering the same accuracy and better features regarding cost, results, biosafety and occupational health, and bioethics and animal welfare.

Improvement of a RT-PCR assay for Yellow Fever virus genome detection

The aim of the present study was to describe an improved protocol of reverse transcription polymerase chain reaction (RT-PCR) for Yellow Fever virus genome detection. A strain of ribonucleic acid of Yellow Fever virus was submitted to the improved protocol of RT-PCR and the amplicons were visualized under ultraviolet transilluminator, purifed and sequenced. The nucleotide sequence obtained was compared with sequences available in GenBank using the tblastx tool. The amplicons produced by the strain of ribonucleic acid of Yellow Fever virus exhibited fragments of 400 and 800 base pairs and the consensus sequence exhibited a similarity of 100% with Yellow Fever virus sequences recorded in GenBank. The improved protocol described in this study allowed Yellow Fever virus genome detection and enabled the elimination of the nested-PCR step, which has been frequently associated with contamination. In addition, it reduced the time of reaction, the cost of reagents and the possibility of sample contamination. New methods of investigating these infections must be elaborated and a continuous vigilance of these viruses in their different vectors and hosts is required to avoid negative impacts on human health, tourism and trade.(AU)

Evaluation of arboviruses of public health interest in free-living non-human primates (Alouatta spp., Callithrix spp., Sapajus spp.) in Brazil.

INTRODUCTION: The aim of the present study was to evaluate the presence of arboviruses from the Flavivirus genus in asymptomatic free-living non-human primates (NHPs) living in close contact with humans and vectors in the States of Paraná and Mato Grosso do Sul, Brazil. METHODS: NHP sera samples (total n = 80, Alouatta spp. n = 07, Callithrix spp. n = 29 and Sapajus spp. n = 44) were screened for the presence of viral genomes using reverse transcription polymerase chain reaction and 10% polyacrylamide gel electrophoresis techniques. RESULTS: All of the samples were negative for the Flavivirus genome following the 10% polyacrylamide gel electrophoresis analysis. CONCLUSIONS: These negative results indicate that the analyzed animals were not infected with arboviruses from the Flavivirus genus and did not represent a risk for viral transmission through vectors during the period in which the samples were collected.

Evaluation of arboviruses of public health interest in free-living non-human primates (Alouatta spp., Callithrix spp., Sapajus spp.) in Brazil

INTRODUCTION: The aim of the present study was to evaluate the presence of arboviruses from the Flavivirus genus in asymptomatic free-living non-human primates (NHPs) living in close contact with humans and vectors in the States of Paraná and Mato Grosso do Sul, Brazil. METHODS: NHP sera samples (total n = 80, Alouatta spp. n = 07, Callithrix spp. n = 29 and Sapajus spp. n = 44) were screened for the presence of viral genomes using reverse transcription polymerase chain reaction and 10% polyacrylamide gel electrophoresis techniques. RESULTS: All of the samples were negative for the Flavivirus genome following the 10% polyacrylamide gel electrophoresis analysis. CONCLUSIONS: These negative results indicate that the analyzed animals were not infected with arboviruses from the Flavivirus genus and did not represent a risk for viral transmission through vectors during the period in which the samples were collected. .