Human Cases of Avian Influenza A (H7N7) Infection - The Netherlands, 2003
Background
Since the end of February 2003, the Netherlands has been reporting outbreaks of highly pathogenic avian influenza A (H7N7) in poultry on several farms. More recently, there have been reports of H7N7 infections among pigs and humans in the Netherlands, and among birds in Belgium and Germany. While it is unusual for people to get influenza infections directly from animals, sporadic human infections and limited outbreaks caused by avian influenza A viruses, including H7N7, have been reported. When such infections are identified, public health authorities monitor the situation closely. Because influenza H7N7 viruses do not commonly infect humans, there is little or no antibody protection against these viruses in the human population. If an avian or other animal influenza virus is able to infect people, cause illness, and spread efficiently from person to person, an influenza pandemic could begin. Additional information on human infections with avian influenza viruses can be found here.
Human Cases of H7N7 Infection in The Netherlands
As of April 25, 2003, the National Influenza Center in The Netherlands reported that 83 confirmed cases of human H7N7 influenza virus infections had occurred among poultry workers and their families since the H7N7 outbreak began in chickens at the end of February 2003. The vast majority (79) of these people had conjunctivitis, and 6 of those with conjunctivitis also reported influenza-like illness (ILI) symptoms (e.g., fever, cough, muscle aches). One person had ILI only (no conjunctivitis) and 2 persons had mild illness that could not be classified as ILI or conjunctivitis. In addition, one individual, a 57-year-old veterinarian who visited one of the affected farms in early April, died on April 17 of acute respiratory distress syndrome (ARDS) and related complications from H7N7 infection. Dutch authorities have reported evidence of possible transmission of H7N7 influenza from 2 poultry workers to 3 family members. All 3 family members had conjunctivitis and one also had ILI.
Public Health Monitoring
CDC is in communication with public health officials in the Netherlands and the World Health Organization (WHO) regarding the recent human cases of influenza A (H7N7) illness in the Netherlands and will continue to monitor the situation. CDC has begun production of a reagent kit that would allow laboratories to identify influenza A (H7N7) viruses. To enhance timely detection of any additional human influenza cases due to these viruses, WHO recommends that affected countries conduct enhanced surveillance for influenza among humans and animals and conduct studies to better understand possible transmission patterns. CDC and WHO have issued no restrictions on travel to the Netherlands. Additional information from WHO can be found at http://www.who.int/csr/don/2003_04_24/en/.
Influenza in the United States
Influenza activity in the United States is at low levels. Influenza A (H1N1), A (H1N2), A (H3N2), and influenza B viruses have been identified in the United States during the 2002-03 season and have been well matched by the current influenza vaccine. The current vaccine does not protect against infection with the influenza A (H7N7) virus. U.S. residents who are traveling outside the United States should consult their physician for advice about whether they should be vaccinated against influenza and about the use of influenza antiviral medications.
Page last modified May 20, 2003