Edison Luis Durigon

Presence of antibodies against H5, H7 and H9 influenza A virus in wild birds in the State of São Paulo, Brazil

Although the natural reservoirs of the avian influenza (AI) virus have been extensively studied in many countries, there is a clear lack of information on this subject in South America, particularly in Brazil. The objective of this study was to conduct a serological survey for H5, H7 and H9 antibodies to AI-subtype viruses in wild birds in the state of Sao Paulo , Brazil. Serum samples were tested using the hemagglutination-inhibition assay. Out of the 31 wild birds sampled between January and December of 2006, seven (22.58%), were seropositive for H5, H7 and H9; four (12.90%) were seropositive for H5 and H7; 13 (41.94%), were seropositive only for H7; three (9.7%), were seropositive only for H9; and four (12.90%) were negative for all three hemagglutinin subtypes. These results indicate that AI viruses belonging to H5, H7 and H9 subtypes circulate among wild birds in the state of Sao Paulo in the form of either concurrent or consecutive infections. This study contributes to the knowledge of AI epidemiology in Brazil, and stresses the need of further detailed and long-term epidemiological and ecological investigation to determine the current status of this virus.

Molecular surveillance of the Newcastle disease virus in domestic and wild birds on the North Eastern Coast and Amazon biome of Brazil

Brazil is one of the worlds largest countries with a rich diversity of wildlife, including resident and migratory wild birds, which may be natural reservoirs of the Newcastle disease virus (NDV). Because Brazil is a major global exporter of chicken meat, the emergence of such a disease may have a huge negative impact not only on the economy due to trade restrictions and embargoes, but also on the quality of life of the population. Samples were collected from 1,022 asymptomatic domestic and wild birds from the Brazilian coast and the Amazon region using tracheal/cloacal swabs and tested by RT-qPCR. The results showed 7 (0.7%) birds were positive for NDV. The positive samples were then isolated in embryonated chicken eggs and their matrix protein genes were partially sequenced, revealing a low-pathogenicity NDV. This study confirms the maintenance of the velogenic-NDV free status of Brazil.

Absence of Anaplasmataceae DNA in Wild Birds and Bats from a Flooded Area in the Brazilian Northern Pantanal

Birds and bats can be considered potential transmitters of some tick-borne diseases, since eventually they carry infected ticks in areas where transit. Pantanal ecosystem is the largest tropical wetland area of the world with more than 582 recorded avian species, contributing to the maintenance of different tick species. The aim of this study was to examine altogether 152 blood samples of several bird and bat species collected in a large flooded area of Pantanal for the presence of members from genera Ehrlichia, Anaplasma and Neorickettsia. None PCR product was obtained, what suggest that wild, domestic birds and bats from Pantanal region are unlikely to play a significant role in the maintenance of tick-borne agents and DNA survey from this species in birds may not be a reliable indicator of exposure.

Características clínico-epidemiológicas da doença Lyme-símile em crianças

BACKGROUND: To determine the prevalence, age distribution, seasonality and clinical characteristics of Lyme-simile disease in Brazilians less than 15 years of age. METHODS. From July, 1998 to November, 2000, a cross-sectional study was conducted in 333 patients with skin rash and fever. Paired blood samples were collected for identification of the pathogens. Only 193 samples which were negative for other pathogens (Parvovirus B19 Human, Herpesvirus 6 Human, Measles, Rubella, Dengue, Scarlet fever and Enterovirus), were tested for borreliosis by Enzyme-Linked Immunosorbent Assay and Western-blotting. Other clinical, socioeconomic, demographic and climatic variables were studied. RESULTS: Prevalence of the disease was 6.2%(12/193). Of the variables studied, there was predominance in: <6 years old (83.2%); females (66.7%); being from the city of Franco da Rocha (58.3 %); and a summer/fall seasonality. The duration of care was 4 days. Signs and symptoms with statistical significance were itching; absence of lip notch and ocular pain; irritability and good clinical condition. Other clinical data presented were: pruritus (90%), irritability (80%) and fever (?38oC) (58.3%) with a duration of 1 to 3 days. Erythema was maculo-papular (40%), urticaria-like (25%) and scarlatiniform (16.7%), occurring predominately on the trunk (60%). There were no primary clinical evidences of Lyme-simile disease in the patients under study. The sensitivity and specificity of the clinical diagnosis as opposed to the laboratory diagnosis was zero. There was no initial clinical suspicion of the disease in the 10 cases studied and followed up for two years that showed no evidence of cardiologic or neurological complications. This is the first study of Lyme-simile in Brazilian children. CONCLUSION: Prevalence of Lyme-simile disease was low, and it was not remembered at the initial diagnosis of those with skin rash. However, practical knowledge is necessary, demanding increased medical attention.

Use of reverse transcriptase polymerase chain reaction (RT-PCR) in molecular screening of Newcastle disease virus in poultry and free-living bird populations

The aim of this study was to evaluate a simple molecular method of reverse transcriptase polymerase chain reaction (RT-PCR) to differentiate Newcastle disease virus strains according to their pathogenicity, in order to use it in molecular screening of Newcastle disease virus in poultry and free-living bird populations. Specific primers were developed to differentiate LaSota—LS—(vaccine strain) and Sao Joao do Meriti—SJM—strain (highly pathogenic strain). Chickens and pigeons were experimentally vaccinated/infected for an in vivo study to determine virus shedding in feces. Validation of sensitivity and specificity of the primers (SJM and LS) by experimental models used in the present study and results obtained in the molecular analysis of the primers by BLAST made it possible to generalize results. The development of primers that differentiate the level of pathogenicity of NDV stains is very important, mainly in countries where real-time RT-PCR is still not used as a routine test. These primers were able to determine the presence of the agent and to differentiate it according to its pathogenicity.

Cacipacore virus as an emergent mosquito-borne Flavivirus

INTRODUCTION: Cacipacore virus (CPCV), a possible bird-associated flavivirus, has yet to be detected in mosquitoes. Our purpose is examining CPCV in mosquitoes from the Amazon region of Brazil. METHODS: Approximately 3,253 Culicidae (grouped into 264 pools) were collected from the Amazon region during 2002-2006 and analyzed using a Flavivirus genus-specific reverse transcription- polymerase chain reaction followed by nested polymerase chain reaction assay and by nucleotide sequencing of amplicons. RESULTS: Nucleotide sequences from five mosquito samples showed high similarity to the those of CPCV originally isolated in the Amazon region. CONCLUSIONS: This is the first report of CPCV-infected mosquitoes which has implications on the arbovirus maintenance in nature and transmission to man.

Investigação sorológica e molecular de agentes virais em onças-pintadas de vida livre no Pantanal de Mato Grosso, Brasil

This study investigates the exposure of free-living jaguars from two federal protected areas in the Pantanal of Mato Grosso, Brazil, to a variety viral agents. These viral agents, particularly causing zoonotic diseases, were analyzed using serological and molecular methods. None of the jaguars was positive by RT-PCR for the molecular detection of avian influenza and West Nile Fever (WNF). Only one animal was serologically positive for Eastern Equine Encephalitis (EEE) by virus neutralization test in VERO cell cultures, representing the first reported case of jaguar exposure to EEE virus. However, all the animals were negative for Western Equine Encephalitis (WEE) virus and Venezuelan Equine Encephalitis (VEE) virus. Eleven jaguars were tested by two tests for the detection of antibodies against rabies virus (Simplified Fluorescent Inhibition Microtest – SFIMT and Rapid Fluorescent Focus Inhibition Test – RFFIT), resulting in five positive animals, two animals in each test and one in both serological tests. Furthermore, three out of 14 samples subjected to the neutralization test were positive for antibodies against canine distemper virus (CDV), and 15 out of 17 samples subjected to the hemagglutination-inhibition test (HI) were positive for antibodies against canine parvovirus (CPV). In view of the findings of this study, it is unlikely that the viruses examined here represent a threat to the jaguar populations in this region.

Investigation of Influenza A, West Nile and Newcastle Disease Viruses in Birds from the Pantanal Wetlands of Mato Grosso, Brazil

The Pantanal is the worlds largest wetland biome with a seasonal flood pulse that attracts a great diversity of birds, many of which are migratory. Birds can be natural reservoirs Influenza A, West Nile and Newcastle Disease viruses. However, the occurrence of carriers for these viruses in the Pantanal was not verified yet. The present study evaluated the occurrence of natural infection by Influenza A, WN and ND virus of birds in the municipality of Pocone, a subregion of the Pantanal in the state of Mato Grosso, Brazil. A total of 76 birds belonging to 11 orders and 20 families were captured using mist nets. The most representative order was Passeriformes, followed by the other nine orders, which included Columbiformes, Psittaciformes, Charadriiformes and Anseriformes. The most representative family was Thamnophilidae, with 16 individuals (21.0%), followed by the family Tyrannidae with 10 individuals (7.6%) and the family Furnariidae, with eight individuals (10.5%). The bird species were identified, and cloacal and tracheal swab samples were collected. The samples were subjected to RNA extraction and tested for the presence of the three agents by real-time polymerase chain reaction (qRT-PCR). All the sampled birds were considered healthy, had no clinical sign of infection, and were tested negative for the three viruses. Based on our findings, we can conclude that Influenza, West Nile and Newcastle Disease viruses were absent from the samples in this region of the Pantanal wetlands during the period of this study.