The World Health Organization (WHO) revealed on Jan. 20 that it has received reports from China of a total of 23 new cases of avian or bird flu in humans. The first report announced seven cases of avian influenza A(H7N9) illness, while the second announced an additional 16 bird flu cases. The 23 new cases include one patient death.
According to health news site Healio, the latest cases bring the total in this outbreak of avian flu to 203, with 53 patient deaths. The Jan 20 announcements from WHO increased the number of known cases by 13 percent. Most of the new patients diagnosed with H7N9 illnesses had a history of exposure to poultry or poultry markets.
Avian influenza A (H7N9) was first reported in humans in March 2013, in China, according to the Centers for Disease Control (CDC). The illness has also been reported from Taiwan. At this time, human-to-human spread of the illness has not been demonstrated but not all patients have been fully evaluated for the origin of their illness.
Influenza is common in birds. It rarely makes the leap to humans, but the H7 variant has been known to cause small outbreaks. In 2003, an outbreak from an A(H7N7) virus in the Netherlands caused several cases of conjunctivitis.
A more well-known avian influenza outbreak is that of A(H5N1). Known as the "highly pathogenic avian influenza (HPAI) A (H5N1) virus infection", the CDC on Jan. 8, 2014 reported about 600 cases from 15 countries since Nov. 2003. Most cases were due to exposure to poultry, but several clusters of human-to-human transmission have been documented. The illness has been fatal in about 60 percent of the cases. The CDC states that the virus is endemic in poultry in six countries, Bangladesh, China, Egypt, India, Indonesia, and Vietnam.
A WHO report from Indonesia in 2006 illustrates several of the ways that humans become exposed to bird flu viruses. As is common in many cultures, the initial case kept chickens and allowed them into the house at night. The patient also gathered the chicken feces for use as a fertilizer. In other cases, patients also killed and prepared sick poultry for meals, rather than lose the use of a valuable food source.
Proper sanitation and hygienic practices would normally prevent poultry handlers and cooks from contact with sick birds. The greatest numbers of H5N1 cases have been in Indonesia, Vietnam and Egypt, where poverty, illiteracy and poor healthcare are factors in human illnesses with avian influenza. Human-to-human spread of the disease has occurred in crowded homes, and in cultures where large groups of relatives sit with the dying for hours at a time.
The CDC is joined by many national and international public health professionals in having concerns about the future of the avian influenza A(H7N9) virus.
... the concern is that this H7N9 virus might either adapt to allow efficient transmission during the infection of mammals or reassort its gene segments with human influenza viruses during the co-infection of a single host, resulting in a new virus that would be transmissible from person to person. Such events are believed to have preceded the influenza pandemics of 1918, 1957, and 1968.