Tweet
Samples of drinking water from poultry cages, which can be collected conveniently and noninvasively,
provide higher rates of influenza (H9N2) virus isolation than do samples of fecal droppings. Studies to
confirm the usefulness of poultry drinking water for detecting influenza (H5N1) should be conducted in
disease-endemic areas.
Pandemic influenza originates from influenza viruses of birds (1). Live poultry markets
play a crucial role in maintenance, amplification, and dissemination of avian influenza viruses
(2?4) and are a risk factor for zoonotic transmission of highly pathogenic avian influenza
(H5N1) viruses to humans (5,6). Maintaining surveillance of live poultry markets for influenza
viruses is therefore important. In routine surveillance of live poultry markets, handling birds for
collecting tracheal or cloacal swabs is often unacceptable to the bird sellers. Because avian
influenza viruses were believed to be transmitted primarily by the oral?fecal route (7), fecal
droppings were therefore regarded as the noninvasive specimen of choice for surveillance
purposes (8). However, emerging evidence from experimental studies indicates that H9N2 (9)
and H5N1 (10) subtypes are shed in higher titers in the upper respiratory tract. We tested the
hypothesis that sampling drinking water is a convenient, noninvasive, and sensitive method for
conducting avian influenza surveillance in live poultry markets.