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EID Weekly Updates

EID Weekly Updates:

Emerging and Reemerging Infectious Diseases, Region of the Americas

Vol. 2, No. 8—26 February 2004
Main Updates index

Update on Avian Influenza

Since our last update of 19 February 2004, 1 new human case of avian influenza has been reported, bring the total to 32 cases and 22 deaths. To date, 2 Asian countries have reported cases in humans; and 8, epizootics of influenza A subtype H5N1 in birds. The outbreaks detected in the USA and Canada do not correspond to the highly pathogenic strain of avian flu (H5N1) currently in circulation in the Asian countries.

The following strategies have been implemented to control the epizootics:

  • Planning or implementation of mass extermination in Thailand, Viet Nam, Indonesia, Pakistan, China, and Taiwan.
  • Vaccination in China (central and southern regions), Taiwan, Hong Kong Special Administrative Region, Indonesia, and Pakistan.

The report issued by the FAO on 23 February 2004 pays special attention to those aspects of zoonotic diseases that exert socioeconomic impact with international repercussions. It also offers recommendations on measures to prevent epizootics of influenza A subtype H5N1 in small and industrial poultry facilities, as well as information on how to send samples to reference laboratories for diagnosis (see annexes from aforementioned document).

Table 1: Current Situation of Avian Influenza—Human Cases and Epizootics
(as of 26 February 2004)
Country Epizootics Virus subtype identified Number of confirmed human cases Comments
Number of provinces affected Species of birds affected Cases Deaths
Cambodia 1 out of 19 Chickens: mostly laying/breeder hens H5N1 0 0 Several localized outbreaks around Phom Penh.
Canada -- Chickens H7 0 0 Investigation underway.
China 16 out of 31 Ducks, chickens, geese, one peregrine falcon in Hong Kong H5N1 0 0 Epizootic out of control (49 confirmed outbreaks).
Indonesia 11 out of 26 Laying and breeding hens. H5N1 0 0 Epizootic widespread, out of control.
Japan 1 out of 9 Egg-laying poultry H5N1 0 0 Epizootic under control since January. New minor outbreak in Oita confirmed as H5N1.
Laos 1 out of 17 Laying hens H5 0 0 Epizootia limited to one area in Vientinae.
Pakistan 1 out of 7 Egg-laying poultry H7 0 0 Epizootic localized but widespread; etiology as yet unconfirmed.
South Korea 8 out of 14 Chickens, ducks H5N1 0 0 --
Taiwan 1 out of 21 Laying hens, colored-feather native chickens H5N2 0 0 Epizootic under control since January.
Thailand 29 out of 76 Chickens (broilers/fryers, laying hens), native poultry, ducks, geese, turkeys, ostrich, quail, peacocks H5N1 9 7 Epizootic out of control; bird-human transmission, with 14 new outbreaks reported to WHO.
USA 4 out of 50 Chickens H7 0 0 Low pathogeneity, under control, investigation underway.
H5N2 0 0 Low pathogeneity, investigation underway.
Viet Nam 57 out of 64 Parent stock for broilers/fryers (chickens) H5N1 23 15 Investigation of family cluster of confirmed cases of subtype H5N1 shows no genetic recombination with human influenza virus.
Total       32 22  

For more information, see the WHO page on Avian Influenza, the International Organization on Animal Health (OIE), and the Food and Agriculture Organization of the United Nations (FAO).

Sources (Consult for additional information.)

Outbreak of Diarrheic Disease from Rotavirus in El Salvador

According to our review of the information available on acute diarrheic syndrome in El Salvador, the incidence of diarrhea is less than it was in 2002 and 2003. On the other hand, taking into account that the number of samples analyzed by the Central Laboratory has not varied significantly with respect to 2003, we can observe an increase in the percentage of positive results for rotavirus.

Up to Epidemiological Week (EW) 7 (21 February 2004), the Central Laboratory studied 233 samples and obtained positive results for rotavirus in 48.4% of them. During EW 7 alone, 133 samples were analyzed, resulting in 53% of those positive for rotavirus.

A total of 108 confirmed cases have been reported of diarrhea from rotavirus, of which 86% have occurred in children under two years of age. The departments most affected have been Santa Ana (with 58.3% of the cases) and San Salvador (with 20.4%). To date, no deaths have been reported.

To deal with this situation, epidemiological surveillance had been strengthened through the daily monitoring of hospital admissions and deaths from acute diarrhea. Efforts are underway to provide reagents for the diagnosis and identification of the strain currently in circulation.

The primary mode of transmission for rotavirus is fecal-oral. The virus is stable in the environment and can remain viable for an extended period, which favors transmission from contact with contaminated surfaces, water, or food. Any prevention and control measures taken should take these aspects into account.

No specific treatment exists for diarrhea. At present, two vaccines are being investigated (testing currently in Phase III), with preliminary results promising in terms of effectiveness and safety. The main strategy in the event of outbreaks is based on reducing mortality from diarrhea, which is generally caused by the accompanying dehydration. Approximately 1 out of every 40 children with gastroenteritis from rotavirus will require hospitalization for the administration of intravenous fluids. Compliance with norms for oral rehydration, as contained in the tried-and-tested IMCI recommendations, is extremely important.

For more information, see the PAHO directories on IMCI and Diarrheal/Enteric Diseases.


  • Ministerio de Salud Pública y Asistencia Social de El Salvador, Epidemiología, Consolidado Nacional de Vigilancia Diaria. (Ministry of Public Health of Social Assistance of El Salvador, Epidemiology, Consolidated Results for Daily National Surveillance; site in Spanish).
  • Report to PAHO from the Ministry of Public Health of Social Assistance of El Salvador.