Update on West Nile Virus (WNV)
United States: This week, 450 new cases of WNV infection in 27 states have been reported to the Centers for Disease Control and Prevention of the United States (CDC) (see Figure 1). At the moment, a total of 6,957 human cases of WNV infection and 149 deaths have been reported. The states with the highest number of cases reported are Colorado (2,170), Nebraska (1,108), and South Dakota (930). Demographic data is available for 6,842 cases (98%), with results showing 3,621 cases among males (53%). The average age was 47.
This year, 10,172 dead birds with WNV infection have been reported from 42 states, the District of Columbia and New York City. In horses, 3,087 infections have been reported in 38 states. A total of 6,421 positive mosquito pools have been reported in 38 states, the District of Columbia, and New York City.
For more information, see the CDC Website:
Source: Division of Vector-Borne Infectious Diseases: West Nile Virus, Centers for Diseases Control and Prevention (CDC), USA.
Canada: Up to 15 October, 378 cases and 10 deaths have been confirmed, of which 252 occurred in the Province of Alberta, 83 in Ontario, 19 in Saskatchewan, and 16 in Manitoba. 839 cases are continuing under study, 690 of which are from Saskatchewan and 121 from Manitoba.
In horses, 446 suspected or confirmed cases have been detected in five provinces. The provinces with the highest number of reported cases are Alberta (180), Saskatchewan (162), and Manitoba (53). In birds, 11,158 have been serologically tested, out of which 1,608 infections have been confirmed. WNV infection has been detected in 534 mosquito pools in Manitoba (259), Ontario (121), Quebec (88), Saskatchewan (35), and Alberta (31).
For more information, see the Health Canada West Nile Virus Surveillance Information page: English | français.
Source: West Nile Virus Surveillance Information, Health Canada.
Equine Encephalitis in Venezuela
In the municipality of Arismendi, State of Barinas, two outbreaks of Venezuelan Equine Encephalitis (VEE) and Eastern Equine Encephalitis (EEE) have been detected beginning at the end of September.
In one of the ranches, with a susceptible population of 15 animals, 2 horses died showing a clinical profile fully compatible with encephalitis. The results of the Hemoagglutination Inhibition (HI) test carried out on the 13 remaining animals indicated the presence of one animal with high titers for EEE. In the second ranch, 3 animals died out of a total of 9, and the results of the HI test pointed to one animal with high titers for both EEE and VEE.
The health authorities (as well as the agricultural authorities) decided to send a technical team to the affected area to carry out an epidemiological tracing. In addition, the movement of animals has been restricted and vaccination of the susceptible population is being carried out. The difficulties to access to the affected area impinge on the implementation of the activities.
Source: Epidemiological report to the Pan American Health Organization (PAHO) by the Ministry of Health of Venezuela.