Dr. A. Prabaharan's

Swine flu is threatening to destroy the health of nations. It is high time the WHO steps in and controls this global epidemic. Countries blame one another is of no use.

J. Gowrishankar writes in The Hindu (2 July 2009)

It was the evening of Saturday June 27, and I felt the prodromal symptoms of an incipient viral upper respiratory infection (“the common cold”) coming on. By Sunday, the infection was fully established with runny nose, sore throat and cough, fever, and the general malaise. On Monday as I am writing this, I wonder, is this the swine flu?

Known in the medical jargon as “swine-origin Influenza A (H1N1) virus” (S-OIV), the swine flu agent is a novel variant of the influenza virus to which all of humanity represents a virgin (that is, immunologically susceptible) population. Much like other viruses that cause the common cold, the swine flu agent is transmitted from one individual to another by the aerosol route. Clusters of human infections first occurred a few months ago in Mexico and then in the U.S. and several West European countries, and India has adopted the strategy of screening travellers from these countries in an attempt to prevent its establishment here. Travellers with common cold-like symptoms have been isolated and their contacts quarantined, and subsequent tests have revealed that a proportion (perhaps 20 per cent) have indeed been infected with the swine flu.

So then, do I have the swine flu? Neither I, nor any of my close contacts, have travelled abroad in the last six days (which is the maximum incubation period for the virus); but the nature of my job has put me in casual contact with fairly large numbers of unknown people who may have travelled abroad during this period. For example, I travelled by air from Hyderabad to Delhi six days ago and returned by air the next day, and I have also attended several meetings in the past week in closed air-conditioned spaces where senior officials who may likely have travelled abroad were present. Thus, there is a very small, but finite, chance that I have the swine flu.

Which makes me contemplate, is this the way that the swine flu will enter and establish itself in the country? That is, through an unscreened secondary carrier who had but a casual contact with the primary carrier, a traveller returning from abroad? If so, the extensive screening now being undertaken in all the international airports in India would at best serve only to delay, not prevent, its spread through the population. The factors which strongly favour such a spread are: that the H1N1 virus is highly infectious (that is, it can easily be transmitted from one person to several others); that person-to-person transmission can occur during the incubation period (that is, before the transmitting individual is even aware that he or she is infected); that every individual in the population is a susceptible host; and that the clinical features of the infection are no different from those of the common cold. The apparent means to contain its spread and severity is either by vaccination (an approved vaccine is at present not available anywhere in the world), or by treatment with antiviral drugs. The latter course of action is not also practicable in the country, given its expense and the fact that a very small proportion of patients with symptoms of the common cold are likely to be suffering from the swine flu.

It is therefore reassuring to believe that, perhaps, no national strategy of action will be needed even if one could be implemented. It is of course entirely feasible that the swine flu pandemic will progress inexorably around the world, but the fear that it would be as devastating as the influenza pandemic of 1918 may fortunately not hold true. The experience from other countries is that the mortality rate has been quite low, about two for every thousand infected, which is not very different from the rate observed for the seasonal influenza infections (although the age distribution of those suffering severe effects appears to be different, with the swine flu affecting school-age children and adults of working age whereas the seasonal flu has typically affected the very young and the very old). In our country, no deaths have so far been reported amongst those who have tested positive for the virus. In my reckoning, therefore, if we do survive the swine flu scare, it will have been because of the benign nature of the infection, not our national preventive strategy.

Ultimately, however, statistics are for populations, not for the individual. Do I have the swine flu? It is here that I become my own doctor, and my own patient. In keeping with the best traditions of academic medicine, I shall take no antibiotics (since the infection is viral, against which antibiotics are ineffective). The only concession I shall make, for the possibility that it is swine flu, is to take my blood sample now and another two weeks later, so that a retrospective diagnosis of H1N1 infection can be unequivocally established from the pair of samples by the “method of the rising antibody titre,” if that is rendered necessary.

Decisions are never easy in the face of uncertainty, I realise: not for individuals, nor for institutions, nor even for governments and international organisations. Is there likely to be an epidemic in this country, and if so how severe will it be? Is there a need for active interventions? Will a programme of mass vaccination be feasible here, and will the vaccine be safe? (An earlier experience in the U.S., in 1976, had been that vaccination against another swine-origin flu virus was associated with a 1:100,000 risk of serious neurological complications.)

The world awaits answers to these and more questions in the months ahead, but I am left to hope that my optimism above is not misplaced.