Two recent publications report that direct bird-to-bird transmission of West Nile virus is possible. The effect of a bird-to-bird transmission on the transmission dynamics of this virus is studied through mathematical modeling. The model still treats the bird-to-mosquito-to-bird as the main transmission route. The results of numerical calculations show that there are changes in the dynamics of ...

West Nile virus causes sporadic cases and outbreaks of human and equine disease in Europe (western Mediterranean and southern Russia in 1962-64, Belarus and Ukraine in the 1970s and 1980s, Romania in 1996-97, Czechland in 1997, and Italy in 1998). Environmental factors, including human activities, that enhance population densities of vector mosquitoes (heavy rains followed by floods, irrigation...

West Nile virus (WNV) is an avian virus that can cause fatal disease in some species of mammals, reptiles and birds. Most clinical cases occur in humans and horses. Approximately 80% of infected humans remain asymptomatic; 20% have flulike symptoms. Less than 1% develop meningitis, encephalitis or acute paralysis, but some of these cases are fatal or result in permanent impairment. Neurological...

A total of 57 cases of West Nile virus infection (54 with neuroinvasive infection and three with fever) were identified in Romania between July and October 2010.The median age of the cases was 53.4 years, with the highest incidence in the age group 60–69 years.The case fatality rate was 8.8%. Cases were distributed in 19 districts in the southern, western, central and eastern parts of the count...

Few studies have investigated the many mosquito species that harbor arboviruses in Kenya. During the 2006-2007 Rift Valley fever outbreak in North Eastern Province, Kenya, exophilic mosquitoes were collected from homesteads within 2 affected areas: Gumarey (rural) and Sogan-Godud (urban). Mosquitoes (n = 920) were pooled by trap location and tested for Rift Valley fever virus and West Nile viru...

A number of mosquito-borne viruses in the family Flaviviridae, genus Flavivirus, cause significant illnesses in humans. These diseases include dengue, yellow fever, West Nile fever, Japanese encephalitis, St. Louis encephalitis and Murray Valley encephalitis. The viruses cause syndromes that can be generally classified as one of three types: haemorrhagic fever, fever with rash and arthralgia, a...

BACKGROUND West Nile virus is a mosquito transmitted virus that can cause disease in humans and horses. A majority of people infected with WNV will have no symptoms or may only experience mild symptoms, such as headaches. About 20% of infected humans develop a flu-like illness characterized by fever; while in the elderly and immunocompromised West Nile virus can cause a more serious neurologic ...

The influence of one virus on the growth of another in tissue culture was investigated. The 17DD High strain of yellow fever virus was found capable of completely suppressing the growth of both the Asibi strain of the same virus and of the heterologous West Nile virus, even when these were added to the cultures in large amounts. The 17DD High strain of yellow fever virus and the West Nile virus...

BACKGROUND West Nile fever virus is a zoonotic arboviral infection maintained in a sylvatic cycle involving mosquito vectors and birds. It is one the arboviruses whose geographical range is expanding because of climate and land use changes that enhance the densities of mosquitoes and promote mosquito-bird-human interactions. We carried out a survey to determine the reservoirs of WNV among wild ...

West Nile virus, a member of the family Flaviviridae, has spread throughout the United States. With more than 9000 cases and 200 deaths in 2003, West Nile virus has become the most common cause of viral encephalitis in several states. West Nile virus encephalitis is a zoonosis. The life cycle of the virus includes mainly birds as hosts and mosquitoes as vectors. Humans are accidental hosts, ins...