Tuesday, January 26, 2016

WHO: Influenza at the Human-Animal Interface - January 2016

 A(H5N1) cases in humans by week of onset, 2004-2016


Reports to the World Health Organization from China and Egypt on human avian flu cases are dramatically lower this winter over last, although it is not yet certain whether that has more to do with delays in reporting than with the actual level of activity.

Despite almost daily headlines in Arabic papers announcing H5N1 cases (confirmed or suspected), Egypt's MOH continues to deny finding any H5N1 infections (see Egyptian MOH Statement: No Bird Flu Cases Since Last Summer).

Similarly, China has substantially reduced (or delayed) their reporting on H7N9 cases since February of last year, preferring to release information in batches, often weeks after the fact.

Today's update from the WHO does provide us with information on several human infections (H5N6 & H9N2) we had not seen previously announced.

Influenza at the human-animal interface

Summary and assessment as of 20 January 2016

Human infection with avian influenza A(H5) viruses

Since the last WHO Influenza update on 14 December 2015, two new laboratory-confirmed human cases of avian influenza A(H5N1) virus infection were reported to WHO.

A 60-year-old male from Mymensing District in Bangladesh was hospitalized on 12 October 2015 with severe acute respiratory infection (SARI). Nasopharyngeal and throat swabs were collected upon hospital admission as part of SARI surveillance, and tested positive for A(H5N1) virus. The patient fully recovered. Prior to illness onset, the patient was exposed to live backyard poultry. The second case was in a 42-year-old male from Sichuan Province in China who had an onset of illness on 27 December 2015. He was hospitalized on 31 December 2015 and remains in a critical condition. This case had history of exposure to poultry.

From 2003 through 20 January 2016, 846 laboratory-confirmed human cases of avian influenza A(H5N1) virus infection have been officially reported to WHO from 16 countries (Figure 1). Of these cases, 449 have died.

In this reporting period, five laboratory-confirmed human cases of avian influenza A(H5N6) virus infection were reported to WHO from China (Table 1). All were sporadic cases and with no further transmission among contacts.

Cases of avian influenza A(H5N6) reported in 14 December 2015 till 20 January 2016

Since 2013 through to 20 January 2016, ten cases of avian influenza A(H5N6) have been detected of which nine were notified to WHO and one was reported in the scientific literature.1 All nine cases notified to WHO had clinically severe disease. The case reported in the literature, a five-year-old female, was a mild case detected through routine surveillance activities.

Various influenza A(H5) subtypes, such as influenza A(H5N1), A(H5N2), A(H5N3), A(H5N6), A(H5N8) and A(H5N9), continue to be detected in birds in West Africa, Europe and Asia, according to recent reports received by OIE. Since last month’s report on detections of avian influenza A(H5) viruses in birds in France, no human infections have been identified. Although the 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) and A(H5N6) viruses in China.

Overall public health risk assessment for avian influenza A(H5) viruses: Overall, the public health risk assessment for avian influenza A(H5) viruses remains unchanged since the assessment of 17 July 2015.


(Continue . . . . .)

This report also adds ten human cases of avian influenza A(H7N9) virus infection were reported to WHO from Guangdong, Jiangsu, Jiangxi and Zhejiang provinces of China, last December's novel H3N2v infection in New Jersey (see my report here), and a single H9N2 infection in a poultry worker in a market in Dhaka City, Bangladesh last October.

While it is entirely possible that the actual number of human infections this winter is lower than last year, the lack openess on the part of the Chinese and Egyptian Ministries of Health over the past year make it difficult to place a lot of confidence in the numbers we're seeing.

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