After reporting nearly 130 H5N1 cases in the first three months of 2015, Egypt has reported only a couple of cases over the past two months – at least according to the figures they have provided to the World Health Organization. While a slowdown in avian flu transmission would be expected once warmer weather sets in, this abrupt halt in case reports is both unexpected, and difficult to explain.
Since the May 1st report, only 2 additional H5N1 cases have been officially reported to WHO, both young children from Fayoum. Additionally, Egypt reported two children infected with the avian H9N2 virus (see previous report here).
Slowdown or not, the number of H5N1 cases reported out of Egypt in the first 3 months of the year more than doubles the highest number racked up by any country in a 12 month period (previous record was 61 by Vietnam in 2005). While more cases may return in the fall, for now this reduction in cases is good news.
Reporting and surveillance of emerging infectious diseases – even under the best of circumstances – is subject to a number of limitations. Some cases may be mild, and never get tested, while others may be misdiagnosed. And when surveillance is conducted in a region with limited resources, and an abundance of other problems (social, economic & political), their completeness or accuracy may suffer further.
So all reported numbers need to be taken with a grain of salt.
These excerpts are from a WHO report (posted today) but dated June 23rd.
Influenza at the human-animal interface
Summary and assessment as of 23 June 2015
Human infection with avian influenza A(H5) viruses
From 2003 through 23 June 2015, 842 laboratory-confirmed human cases of avian influenza A(H5N1) virus infection have been officially reported to WHO from 16 countries. Of these cases, 447 have died.
Since the last WHO Influenza update on 1 May 2015, two new laboratory-confirmed human cases of avian influenza A(H5N1) virus infection was reported to WHO from Egypt, both from Fayoum governorate. A three-year-old female, with illness onset on 8 June was hospitalized on 10 June, and had laboratory-confirmation of infection with an avian influenza A(H5N1) virus on 16 June 2015. A two and a half-year-old male with illness onset on 13 June, was hospitalized on 16 June, and had laboratory confirmation of infection with avian influenza A(H5N1) on 20 June 2015. Both had exposure to poultry, were given oseltamivir, and remain under treatment.
Various influenza A(H5) subtypes, such as influenza A(H5N1), A(H5N2), A(H5N3), A(H5N6) and A(H5N8), continue to be detected in birds in west Africa, Asia, Europe, and North America, according to reports received by OIE. Although these influenza A(H5) viruses might have the potential to cause disease in humans, so far no human cases of infection have been reported, with exception of the human infections with influenza A(H5N1) viruses and the three human infections with influenza A(H5N6) virus detected in China since 2014.
Overall public health risk assessment for avian influenza A(H5) viruses: Whenever avian influenza viruses are circulating in poultry, sporadic infections and small clusters of human cases are possible in people exposed to infected poultry or contaminated environments, therefore sporadic human cases would not be unexpected.
With the rapid spread and magnitude of avian influenza outbreaks due to existing and new influenza A(H5) viruses in poultry in areas that have not experienced this disease in animals recently, there is a need for increased vigilance in the animal and public health sectors. Community awareness of the potential dangers for human health are essential to prevent infection in humans. Surveillance should be enhanced to detect human infections if they occur and to detect early changes in transmissibility and infectivity of the viruses.
Human infections with avian influenza A(H9N2) viruses in Egypt
Two laboratory-confirmed cases of human infection with avian influenza A(H9N2) virus were reported to WHO from Egypt. Both cases occurred in children (a seven-year-old female and a nine-month-old female) from Cairo governorate and both were detected through influenza-like illness (ILI) surveillance. The cases had mild illnesses, were not treated with antiviral medications, and were not hospitalized. One case had exposure to poultry and the second had likely exposure to an environment contaminated with poultry waste.
These are the second and third cases of human infection with influenza A(H9N2) viruses reported from Egypt. Avian influenza A(H9N2) viruses are known to be circulating in poultry populations in Egypt.
Overall public health risk assessment for avian influenza A(H9N2) viruses: Further human cases and small clusters could occur as this virus is circulating in poultry populations across Asia and Middle East. This virus does not seem to transmit easily between humans and tends to result in mild clinical disease, therefore the current likelihood of community-level spread and public health impact of this virus is considered low.