The emergence of influenza A(H1N1) virus in humans was first detected in late April and within six weeks the swine flu spread to 74 countries, infecting nearly 30,000 and killing nearly 140 people. In the second week of June, the World Health Organisation (WHO) declared swine flu as a pandemic — the first flu pandemic in 40 years. If data for assessing the risk were essential during the early stages, the WHO has now changed its requirements for data sharing. Countries where the infection is widespread need not submit individual laboratory-confirmed cases to the WHO but countries that record the first cases of swine flu must report them and provide weekly aggregates. The rationale is simple. Since influenza A is widespread in many countries, detection and laboratory confirmation of individual cases will put the healthcare system, especially in the developing countries, under needless strain. In fact, it might even divert attention from the challenge of studying severe or exceptional cases. Using available data, the world health body has been able to assess the level and nature of the risk posed by swine flu. Keeping count of the number of infections will be a pointless exercise. Many cases go undetected as the infection is self-limiting and the symptoms are mild in a majority of the cases. Countries should, however, look out for sudden changes in the patterns of the disease, virulence, transmission, and the kinds of people infected, and report such cases to the WHO.
There is no evidence of any other pandemic being detected so early and watched so closely. After the sobering experience of the bird flu crisis nearly a decade ago and the severe acute respiratory syndrome (SARS) outbreak in 2003, virtually all countries have learnt the importance of sharing data with the world body in something like real time. But how will the world respond if swine flu takes root in the southern hemisphere, particularly in those African countries where health conditions for a high proportion of people are compromised? Will the infection become more virulent and the mortality rate increase under these circumstances? Further, some of the least developed countries lack the expertise and the systems to detect and confirm the infection in thousands of patients. How the WHO and the developed and major developing countries respond to this challenge, and whether affordable supply of medicines and vaccines can be assured should the pandemic becomes more virulent, will determine the state of preparedness of the world to fight the virus.