2011-05-01-世界卫生组织-Influenza_at_the_human-animal_interface_summary_and_assessment,_2_May_2011_3页_150kb

报告摘要

Influenza at the Human-Animal Interface: April 2011 Summary

Core Content

This document provides a summary of avian influenza H5N1 and other animal influenza viruses reported to the World Health Organization (WHO) in April 2011, focusing on human infections and the situation at the human-animal interface.

Human Infections with Avian Influenza H5N1

Confirmed Cases: As of 30 April 2011, 552 confirmed human cases of H5N1 infection were reported from 15 countries.
Case Fatality Rate (CFR): The CFR was 58%, with 59% in March 2011.
Human-to-Human Transmission: Limited human-to-human transmission has been identified, with no community-level spread since 2003.
April 2011 Cases: Three human cases were reported in April 2011 from Cambodia (1) and Egypt (2). Additionally, Egypt reported eight cases with onset in February and March that were not previously included in summaries.
Contact with Poultry: All reported human cases had contact with poultry.
Endemic Status: Egypt and Indonesia have officially declared H5N1 endemic in poultry. The virus is also circulating in poultry in Bangladesh, China, India, and Vietnam.
Cambodia Situation: Sporadic reintroduction of H5N1 into poultry populations is thought to occur in Cambodia, with poultry die-offs reported in Prey Veng province, though no outbreaks have been reported since February 2011 in Kandal province.
Seasonal Trends: In Egypt, the number of human cases follows a seasonal pattern, with an expected decline in summer. However, sporadic human cases may continue as long as the virus circulates in poultry.
Survival Rates: In Egypt, survival rates in affected children are better than in adults.
Intersectoral Collaboration: Egypt continues to collaborate between animal health and public health sectors to mitigate H5N1 risks at the human-animal interface.

Human Infections with Other Animal Influenza Viruses

No Reports: No human infections with other animal influenza viruses were reported to WHO in April 2011.

Other Animal Influenza

Bangladesh Live Bird Markets: A recent study reported a 23.0% prevalence of influenza infection in birds in live bird markets in Bangladesh.
Subtype Distribution: Nearly all isolates (94%) were non-pathogenic H9N2 subtype, while H5N1 was present at very low levels (0.08%).
H9N2 in Humans: Human infections with H9N2 have only been reported from China and China Hong Kong SAR.

Key Information

Epidemiological Curve: Figure 1 illustrates the epidemiological curve of H5N1 cases in humans in Egypt by month of onset, showing a seasonal pattern.
Surveillance Trends: The trend of decreasing non-endemic countries reporting H5N1 in poultry or wild birds continues, likely due to warmer weather.
Risk Factors: Human cases are possible whenever the virus is circulating in birds, emphasizing the importance of monitoring and prevention at the human-animal interface.