31 July 2006
In the August 2006
issue of Emerging Infectious Diseases
Yingst, Saad, and Felt from the Naval Medical Research Unit (NAMRU-3) in
Cairo, Egypt reported finding domestic cats with fatal H5N1 avian flu infection
in February 2006 in the Erbil governate of Kurdish northern Iraq. The infection of the cats occurred near the
time of the outbreak of H5N1 in northern Iraq (Sulymaniyeh and Erbil
Governates).
The authors reported
that the cats had the more recent
“clade 2” H5N1 virus, unlike earlier infections of tigers and leopards
in Thailand with the “clade 1” H5N1 viruses. Specifically, this clade 2 virus
is very similar to the H5N1 clade 2 viruses found at Qinghai Lake in the
western China in the spring of 2005 associated with the deaths of several
thousand migratory birds. In addition,
the authors reported the unusual finding of severe hemorrhagic pancreatitis in
the two cats that underwent necropsy.
Their brief report can be found online on the CDC website at www.cdc.gov/eid.
The outbreak study
was performed after the government of Iraq requested a World Health
Organization (WHO) investigation. The
NAMRU-3 team also participated in the H5N1 avian flu investigation in
Azerbaijan, using the innovative PCR diagnostic equipment that had been adapted
by them for use in the field, thereby shortening the time required to make the
diagnosis of H5N1 by avoiding the need to transport specimens to a distant
reference laboratory.
In the Iraq study of
domestic cats, the H5N1 virus was found in the large intestine, pancreas, and
lungs of both cats, and in the feces of the one cat in which it was looked for.
The route of infection of the cats was not proven, but might have occurred by
consumption of H5N1-infected chickens or geese given that such species were
also found to be infected with H5N1 at the same time as the cats. No evidence
of cat-to-cat transmission was established, as likely occurred between tigers
in a zoo in Thailand (Emerg Infect Dis (EID) 2005; 5:699-701).
Clade 2 H5N1
infections, antigenically distinct from the clade 1 H5N1 viruses that appeared
in 2003-2004 in Vietnam and Thailand, are now found in multiple nations inside
and outside Asia. These clade 2 viruses have recently lead to the announcement
that WHO is providing clade 2 H5N1 viruses for candidate vaccine development,
in addition to the earlier clade 1 H5N1 viruses. A color map of the early
geographical distinction between clade 1 and clade 2 H5N1 viruses in Asia can
be found in the paper published by the WHO Global Influenza Program
Surveillance Network in October 2005 in this same journal (Emerging Infectious
Diseases (EID) volume 11: pages 1515-1521.
Director, Center for
Biologic Counterterrorism and Emerging Diseases,
EROne Institutes,
Washington Hospital Center Dept. of Emergency Medicine
Adjunct Professor,
Department of Microbiology and Immunology
Georgetown University
School of Medicine, Washington, DC
Website: www.BePast.org e-mail:Daniel.r.Lucey@Medstar.net