H5N1 In India and Pakistan Raise Pandemic Concerns
Recombinomics Commentary 12:54
February 1, 2008
India has put 26 people in isolation with bird flu symptoms and hundreds more people are being monitored,
"The preliminary tests for bird flu are negative, but more tests are being conducted and the list of sick people reviewed every day," R.S. Shukla, a senior health official, told Reuters. To the west in neighbouring Pakistan, authorities said bird flu had been detected at a poultry farm on the outskirts of its biggest city, Karachi. But officials said on Friday there was no likelihood of any human infection.
"We are now monitoring the workers on the farm as well as another one adjacent to it," said an official of the Sindh provincial government.
The above comments on human H5N1 cases in India and Pakistan raise pandemic concerns. Closely related H5N1 has been confirmed in birds in both countries (see satellite map here and here).
Pakistan has confirmed H5N1 in many patients in late 2007. Although WHO was only able to confirm one, due to sample degradation, WHO acknowledged human to human transmission based on clinical and epidemiological evidence. The confirmed case was fatally infected with H5N1 and was a brother of the index case, who also tested positive in local testing after culling poultry in northwestern Pakistan. Another brother also died, although no lab results were available. However, at least four of the brothers, including the two how dies, had suspected or confirmed pneumonia, and disease onset dates indicated H5N1 was transmitted human to human.
The outbreak near Karachi suggests the same H5N1 is still in circulation and poses a significant risk to populations linked to the outbreak. Similarly, the patients in India are also at risk. Several have been reported to have pneumonia or breathing difficulties. However, not all of the patients in Pakistan developed respiratory problems, so H5N1 infections need not cause low respirtaory tract problems. Mild H5N1 in Egypt, in the absence of pneumonia, has also been reported.
Thus, although initial tests have been negative in India, the linkage of patients with fever and influenza symptoms after exposure due to culling or eating infected birds, raise additional concerns that H5N1 infected patients are not being detected or reported.
In 2006 there were highly suspect patients in India that were not H5N1 confirmed, casing serious doubt about the detection assays and methodologies in India. India has also failed to detect H5N1 in any wild birds, even though Bangladesh has reported H5N1 positive crows in areas adjacent to West Bengal.
Similarly, migratory birds from China, Russia, and Mongolia winter in India, yet none of these birds has been reported to be H5N1 positive in India, even when the dead migratory birds are collected within a few miles of H5N1 confirmed poultry and dead resident wild birds including crows, pigeons, hawks, and owls.
Thus, the outbreaks in Pakistan and India raise pandemic concerns because the demonstrated ability of the H5N1 to infect humans, and widespread denials of human infections in India and Pakistan.
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