Fujian Province – Credit Wikipedia
# 7235
Although we typically learn about avian flu cases when they present – usually in deteriorating condition – to local hospitals, occasionally we only learn about them through routine surveillance . . . weeks or months after test samples were initially collected.
Often these retrospective discoveries involved mild or moderate illness – such as we’ve seen with the first six cases of H5N1 in Bangladesh (see IEDCR On The Bangladesh H5N1 Cases) – and occasionally in Egyptian children.
While these milder cases can be reassuring that avian flu infections aren’t always severe, they do suggest that some number of infections are going undetected in the community.
And as undetected cases are not isolated, that opens the possibility of further spreading the virus.
Today, Fujian Province announced the detection of a `mild’ case of H7N9 from late April – that of a 9 year-old who was treated in a local hospital where a routine throat swab was collected and then forwarded to China’s CDC – and who’s test results just recently came back positive for the virus
The child has recovered, apparently without incident, and new tests (taken in May) are now negative. This (machine translation) from Xinhua News:
Fujian Province of human infection with H7N9 avian influenza confirmed cases increased to five cases
May 6, 2013 16:09:25
Source: XinhuaXinhua Fuzhou, May 6 (Mengzhao Li Wen Ye) Fujian
Provincial Health Bureau today released news that, Fuzhou to report a case of a retrospective of human infection with the H7N9 avian influenza confirmed cases, has been cured. Up to now, Fujian found five cases of human infection with the H7N9 avian influenza confirmed cases, including one case cured, 4 cases of hospitalization and no deaths.
Newly diagnosed cases of children with Zhang, male, 9 years old, now living Cangshan District, Fuzhou. The afternoon of April 26, fatigue, diarrhea, night fever treatment in the Second Hospital of Fuzhou, April 27, outpatient treatment improved, no obvious clinical symptoms on April 29. Second Hospital of Fuzhou Fujian influenza surveillance sentinel hospitals, children with throat swab for inspection in accordance with the provisions acquisition, Fuzhou CDC routine testing, the results of human infection of H7N9 avian influenza virus nucleic acid positive, sent to the provincial CDC review of detection confirm.
May 4, 5, respectively, collected swabs, detection of human infection with the H7N9 avian influenza virus nucleic acid were negative, the Fujian provincial-level Expert Group to discuss, diagnosed as a retrospective of human infection of H7N9 avian influenza confirmed cases. The children of patients with mild, the children have been cured.
Since the alert first went out, the immediate emphasis has been on testing patients presenting with severe, unexplained pneumonia.
While throat and nasal swabs (not necessarily the best sampling method) from less ill patients are often collected, they end up in the testing queue, and results are often delayed.
The routine testing of these samples may well turn up more `mild’ cases in the days or weeks to come, and that may give us a clearer idea of the true CFR (case fatality ratio) of this virus.
Seroprevalence studies should give us even more information, as they look for telltale antibodies which develop several weeks after exposure to the virus.
While the recent drop in new cases is encouraging, until the source of the virus – and how it is jumping to humans – can be determined, it is a bit soon to assume this outbreak is over.
