EID Weekly Updates:

Emerging and Reemerging Infectious Diseases, Region of the Americas

Vol. 1, No. 8—28 August 2003
Main Updates index

• Jungle Yellow Fever (JYF) in the Americas
• West Nile Virus (WNV) in the USA and Canada
• Acute Respiratory Disease in British Columbia, Canada

Jungle Yellow Fever (JYF) in the Americas

Up to August 26, a total of 181 confirmed Jungle Yellow Fever cases have been reported to the Pan American Health Organization (PAHO), with 75 deaths. This represents an additional 21 cases since August 6. The distribution of cases and deaths by country is shown in Table 1.

Table 1: Jungle Yellow Fever, Reported Cases and Deaths
(by country, Region of the Americas, to 26 August 2003)

Since mid-June, outbreaks have been identified in the Colombian-Venezuelan border and in Peru, which represents almost half of all cases reported in 2003.

• In Peru, the outbreaks occurred in the Departments of Cuzco (Distritos de Echerate y Villacamba) and San Martin (Distritos de Bajo Biavo, Campanilla y Pajarillo).
• In Colombia, the cases were identified in the Department of Norte de Santander, affecting the counties of Convención, Cucutilla, El Carmen, El Tarra, Encino, Teorama y Tibú.
• In Venezuela, the outbreak extended to the States of Tachira (counties of Fernando Feo, Libertador y Uribante) and Zulia (counties of Jesus Maria Semprun, Machiques, and Rosario de Perija). Most of cases reported were in non-immune migrants.

Outbreak-control measures are underway in the affected areas. The Pan American Health Organization (PAHO) is following the epidemiological investigations closely and providing the necessary technical cooperation to countries to control the situation. The last cases reported in these outbreaks for Colombia, Peru, and Venezuela were in the Epidemiological Weeks 30, 31 and 32, respectively. However, suspected cases are still under investigation.

The occurrence of extensive outbreaks of yellow fever in enzootic areas emphasizes the need for countries to follow closely the recommendation to immunize all residents and travelers to those areas.

Source: Ministries of Health of Bolivia, Brazil, Colombia, Peru and Venezuela.

West Nile Virus (WNV) in the USA and Canada

USA, 27 August 2003: The Centers for Disease Control and Prevention (CDC) in Atlanta reported 1,482 cases and 24 deaths from West Nile Virus. The most affected state has been Colorado, with 635 cases (43% of the total) and 6 deaths (25% of the total), followed by South Dakota with 206 cases (14%) and 2 deaths (8%) and Nebraska with 190 cases (13%) and 4 deaths (17%). To date, detailed information is available on 790 cases, of which 356 (45%) were classified as mild forms of the disease, 319 (40%) were classified as serious forms-encephalitis or meningitis-and 115 (15%) were not clinically classified. More information is available on the CDC website.

Source: Division of Vector-Borne Infectious Diseases: West Nile Virus, Centers for Diseases Control and Prevention (CDC), USA.

Canadá, 27 August 2003: Nine confirmed cases of West Nile Virus infection have been reported. The province most affected has been Saskatchewan, with seven confirmed cases. Another 58 probable cases are being investigated. To date, no deaths have been reported. More information is available on the Health Canada website.

Source: West Nile Virus Surveillance Information, Health Canada.

Acute Respiratory Disease in British Columbia, Canada

An outbreak of respiratory illness in an aged care facility in Canada has now been extensively investigated for SARS and WHO concludes the disease is not SARS. On 14 August, Canadian public health officials reported to WHO that an unidentified respiratory disease in a Surrey, British Columbia health care facility had infected 143 residents and staff. Some initial testing suggested the SARS coronavirus may have played a role.

At present, WHO and Canadian health authorities have gathered enough evidence to conclude that the outbreak in British Columbia is not SARS. Analysis from laboratories in Canada and the United States did not confirm the initial concern that SARS had mutated into a milder disease.

Two lines of evidence have converged to dismiss the SARS concern:

1. Clinically, the disease itself was strikingly different from the SARS outbreak in the spring. The features of the current outbreak included a low case fatality, runny nose, lack of fever in most patients, and no SARS-like changes in the lung seen on X-ray.
2. Now, sequencing of a portion of the virus causing the outbreak has led to the finding that it was not the SARS coronavirus but another human coronavirus known as OC43. This virus, which is one of the causes of the common cold, has been associated with respiratory outbreaks in aged care facilities in other countries.

In terms of SARS, Canada continues to be a safe destination for travelers and travelers from Canada pose no exceptional risk to other countries.

This outbreak has no international public health implications.

For further information on this outbreak and on SARS, see the websites for the British Columbia Center for Disease Control (BCCDC) and the WHO SARS page.

Sources: British Columbia Center for Disease Control (BCCDC) and the World Health Organization (WHO).