West Nile infections are occurring early in North America
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《英国医生杂志》
The United States is seeing West Nile virus infections earlier than usual. The Centers for Disease Control and Prevention (CDC) had reported two cases in humans—:one in Arizona and one in New Mexico—:and avian, animal, or mosquito infections in 17 states by 1 June. Last year more than 260 people died from the disease in the United States.
ProMedmail.org, a service of the International Society for Infectious Diseases, said West Nile virus was now widespread throughout the United States and in nearby regions in Canada and Mexico. The infection would probably move south into Mexico.
Arizona and New Mexico have a border with Mexico, and by 27 May the Mexican authorities had reported 18 seropositive birds and 287 seropositive horses. Health Canada had reported eight dead birds infected with West Nile virus in Ontario by 4 June.
The mosquito season in Arizona is usually August and September. ProMedmail reported that Dr Jonathan Weisbuch, head of the Maricopa County Department of Public Health, which includes the city of Phoenix, said "This is much earlier than we expected. It抯 going to be a longer season. We could see several hundred cases."
In California, an increased number of wild birds, predominantly crows, have been found to be infected with West Nile virus in the southern part of the state. No human or horse cases have been reported.
In Indiana, mosquitoes infected with West Nile virus were found near the city of Indianapolis in an area where the virus was also found last year. Again, the infection was detected earlier than in 2003, which local health officials attribute to warm weather and rain.
West Nile virus was first identified in New York City in 1999. Last year it appeared west of the Continental Divide (west of the Rockies mountain range) for the first time. Human cases were reported in 45 states and the District of Columbia. The virus caused 9862 cases in the United States and 264 deaths, according to the CDC. The state most affected was Colorado, with 2947 cases and 63 deaths.
There is no human vaccine against the disease, although there is one for horses. People are cautioned to wear long sleeved shirts, long trousers, use a mosquito repellent, and avoid being out between dusk and dawn, when mosquitoes bite. They are also advised to use screens on doors and windows, drain stagnant water, and report dead birds to local health departments.(New York Janice Hopkins T)
ProMedmail.org, a service of the International Society for Infectious Diseases, said West Nile virus was now widespread throughout the United States and in nearby regions in Canada and Mexico. The infection would probably move south into Mexico.
Arizona and New Mexico have a border with Mexico, and by 27 May the Mexican authorities had reported 18 seropositive birds and 287 seropositive horses. Health Canada had reported eight dead birds infected with West Nile virus in Ontario by 4 June.
The mosquito season in Arizona is usually August and September. ProMedmail reported that Dr Jonathan Weisbuch, head of the Maricopa County Department of Public Health, which includes the city of Phoenix, said "This is much earlier than we expected. It抯 going to be a longer season. We could see several hundred cases."
In California, an increased number of wild birds, predominantly crows, have been found to be infected with West Nile virus in the southern part of the state. No human or horse cases have been reported.
In Indiana, mosquitoes infected with West Nile virus were found near the city of Indianapolis in an area where the virus was also found last year. Again, the infection was detected earlier than in 2003, which local health officials attribute to warm weather and rain.
West Nile virus was first identified in New York City in 1999. Last year it appeared west of the Continental Divide (west of the Rockies mountain range) for the first time. Human cases were reported in 45 states and the District of Columbia. The virus caused 9862 cases in the United States and 264 deaths, according to the CDC. The state most affected was Colorado, with 2947 cases and 63 deaths.
There is no human vaccine against the disease, although there is one for horses. People are cautioned to wear long sleeved shirts, long trousers, use a mosquito repellent, and avoid being out between dusk and dawn, when mosquitoes bite. They are also advised to use screens on doors and windows, drain stagnant water, and report dead birds to local health departments.(New York Janice Hopkins T)