EID Weekly Updates:

Emerging and Reemerging Infectious Diseases, Region of the Americas

Vol. 2, No. 21—24 June 2004
Main Updates index

• Report Confirms the Circulation of West Nile Virus (WNV) in Puerto Rico
• Current Situation of Jungle Yellow Fever (JYF) in the Americas: Outbreaks in Peru and Bolivia

Report Confirms the Circulation of West Nile Virus (WNV) in Puerto Rico

18 June 2004: In a press release, the Secretary of Health of Puerto Rico confirmed the detection of West Nile Virus (WNV) in three horses from the area around Fajardo, based on the confirmation issued this week by both the Department of Health of Puerto Rico and the Dengue Division of the Centers for Disease Control and Prevention (CDC), located in San Juan.

These new findings can be added to those on the two native birds that tested positive for WNV among the 183 captured in the Roosevelt Roads area in Ceiba, which were considered to be the first instances where the virus was be detected in Puerto Rico.

Faced with the introduction of West Nile Virus, authorities are working to strengthen the surveillance system for the early detection of cases among humans, in animals, and in vectors. To date, no human cases have been reported.

The Department of Health issued a strong warning to the population to adhere to personal protection for disease prevention now that this new agent has been introduced into Puerto Rico.

Source: Press release from the Department of Health of Puerto Rico contained in an e-mail communication sent to the PAHO Communicable Disease Unit.

Current Situation of Jungle Yellow Fever (JYF) in the Americas: Outbreaks in Peru and Bolivia

24 June 2004: Up to 23 June 2004, the Ministries of Health of Colombia, Peru, Brazil and Bolivia reported to the Pan American Health Organization (PAHO) the occurrence of 86 confirmed cases of Jungle Yellow Fever (JYF), with 41 deaths. In all the countries, cases occurred predominantly among males over the age of 15 who work in the countryside. The case distribution by Epidemiological Week (EW) and by country is shown in Figure 1.

• Peru has reported 52 cases, with a case-fatality rate of 52%. These cases were identified in the districts of Echerate (1 case), in the Department of Cuzco; Cholón (1), Daniel Alomia Robles (1), Huánuco (1) and José Crespo y Castillo (5) in the Department of Huánuco; Junín, (1), Perené (4) and Pichanaqui (17), in the Department of Junín; Ramón Castilla (1) in the Department of Loreto; Huepétuhe (5), Laberinto (1) and Manú (1) in the Department of Madre de Dios; Campanilla (7), La Banda de Shiclayo (1), Moyobamba (3), and Nueva Cajamarca (2), in the Department of San Martín. Another 31 suspected cases are undergoing epidemiological and laboratory investigation.
• Bolivia: The 9 cases reported by Bolivia occurred in the municipalities of Palo Alto (2 cases) in the Department of La Paz; and in San Ignacio de Velasco (6) and Yapacani (1), in the Department of Santa Cruz. The fatality rate is 40%. Another 3 suspected cases coming from the Departments of La Paz and Cochabamba are pending laboratory confirmation.
• Brazil: The probable sites of infection of the 3 cases reported by Brazil are the municipalities of Parauapebas (2 cases) in Pará state and Iranduba (1) in Amazonas state. The cases from Brazil correspond to Epidemiological Weeks (EW) 11 and 12, which ended respectively on 20 and 27 March 2004.
• Colombia has reported 22 cases, with a case-fatality rate of 36%. These cases are a continuation of the extensive outbreak that began in 2003 in the Department of Norte de Santander, which later extended north to the Departments of Cesar, la Guajira, Magdalena, and then south to the Department of Meta. The last confirmed case showed initial symptoms appearing during EW 8, which ended on 28 February 2004.

Considering the extensive infestation by Aedes aegypti in all the countries of the Region, with the exception of the continental part of Chile, the occurrence of outbreaks increases the risk of the reurbanization of Yellow Fever. The PAHO Technical Advisory Group (TAG) on Vaccinations has systematically recommended that the countries vaccinate all persons residing in enzootic areas in the Americas for Yellow Fever, as well as all travelers to those areas, and introduce routine vaccination for children against the disease. Also highly recommended is putting into place control measures against A. aegypti in accordance with PAHO recommendations for the control of this vector.

Evidence of the spread of Yellow Fever, through the confirmation of at least one human case and of epizootics (dead monkeys), is sufficient grounds for initiating outbreak-control measures in the affected municipality and immediate vicinity. These measures include vaccinating all residents who lack proof of previous inoculation against Yellow Fever, vaccinating all those traveling to the area, actively searching for suspected cases, putting into place surveillance of both febrile icteric syndrome and epizootics, in addition to declaring epidemiological alerts. If new cases are identified in other municipalities of the Region, the vaccination ring should be expanded along with other control measures.

Source: Reports to PAHO from the Ministries of Health of Colombia, Peru, Brazil and Bolivia; data in Figure 1 also include information from reports sent to PAHO by the Ministry of Health of Venezuela.