West Nile appears in Brazil

[Tonka]

http://noticias.terra.com.br/ciencia/noticias/0,,OI5287446-EI238,00-Febre+do+Nilo+Ocidental+aparece+pela+primeira+vez+no+Brasil.html

Portuguese to English translation

West Nile appears in Brazil August 9, 2011 10:28 ? Comments

The first time in Brazil was identified virus West Nile fever, a disease with symptoms similar to dengue and also transmitted by mosquitoes. The discovery, by researchers from Fiocruz, occurred in the Pantanal. Five horses had antibodies against the virus, ie, suffered infections.

Several species of mosquitoes are capable of transmitting the virus. Humans and other mammals can get sick, but does not reinfect the insect, unlike dengue. Only birds and reptiles do, restarting the cycle.

symptoms
Often the infection is asymptomatic in humans. In other cases, symptoms are fever, body aches and nausea. Some patients have more severe forms of evil, which affect the central nervous system. The study also failed to identify what type of mosquito is the vector of the disease in Brazil.

In 1999, West Nile fever has come to America, causing dozens of deaths in the United States. Since then, cases have appeared in Colombia, Venezuela and Argentina, in horses and birds.

[Gert van der Hoek]

Re: West Nile appears in Brazil

Published Date 09-AUG-2011


WEST NILE VIRUS, EQUINE - BRAZIL: (MATO GROSSO DO SUL) FIRST REPORT

Date: Mon 8 Aug 2011

Source: Estadao [in Portuguese, trans. & summ. Mod.TY, edited]

http://www.estadao.com.br/noticias/i...l,755438,0.htm


Horses in Pantanal have antibodies to West Nile virus [WNV], according
to researchers at the Instituto Oswaldo Cruz [IOC] and the USP
[Universidade de Sao Paulo]. In the most serious manifestation of WNV
infection the disease affects the central nervous system, but it has
not been recorded in humans in the country. 5 horses have antibodies
against the virus, proof that they have been infected. Since its
arrival in the Americas in 1999 in the United States of America, the
virus has descended in the continent. Cases have been diagnosed in
horses and birds in Colombia and Argentina.

The IOC researchers tested blood samples from 168 horses and 30
alligators [caimans?] from the Nhecolandia region, in Mato Grosso do
Sul [state]. Also, 1204 mosquitoes of 10 different species were
captured. Antibody tests were positive for 5 of the horses and none of
the alligators. None of the mosquitoes were found to be carrying the
virus.

The veterinarian Alex Pauvolid-Correa, the main author of the study,
explained that it is still not possible to know which insects can
serve as efficient vectors of the disease [virus] in the country. The
scientists have now begun a more comprehensive study, capturing a
large sample of mosquitoes. Tests of these new samples are in
progress, indicated Correa, who is doing his doctoral studies in the
IOC and the Centers for Disease Control and Prevention in the US.

In parallel, the Clinical and Molecular Virology Laboratory of the
Instituto de Ciencias Biomedicas of the USP has also found indications
of WN virus activity in the country. A researcher, Tatiana Lopes
Ometto, began a doctoral program in 2008 with the theme of virus
monitoring in equines and avians. She has obtained similar results to
those of the IOC. "We tested 1156 blood samples -- 678 equine and 478
avian -- obtained in Nova Brasilandia (190 km [118 mi] from Cuiaba, in
Mato Grosso)", Tatiana stated. "We confirmed the presence of
antibodies against the virus [presumably WNV] in 4 equines." The
animals were native to the region -- a region of transition from
Cerrado to Pantanal. Therefore, they cannot be imported cases
[infections].


[The Pantanal region is a stopping place for migratory birds. The
virus [WNV] was found in Argentina (in horses [and in one human case
(see ProMED-mail archive no 20061228.3642) and is endemic in North
America. Birds are natural reservoirs. It was just a matter of time
before the virus was found at some point along the route of bird
migration. - Mod.LJS

Serological results, especially of flavivirus serology, must be
interpreted with considerable caution because of antigenic cross
reactions among members of this virus family. The type of serological
test employed in this study is not specified, and would be of interest
to know. Isolation of WNV or demonstration of WNV-specific genomic
sequences by RT-PCR would provide more reliable proof or WNV presence
than just serology does.

In fairness to the authors, however,
demonstration of virus presence directly from horses in these cases is
not always possible retrospectively. Prospective sentinel herd studies
and vector mosquito collections in the same areas at the same time
could provide information on the time of virus infection and
transmission that retrospective studies cannot. ProMED-mail would
appreciate receiving any additional information as it becomes
available.

ProMed