Concerns in India

R. RAMACHANDRAN

THE outbreak of the foot-and-mouth disease (FMD) in the United Kingdom and in some other parts of Europe has trigerred unwarranted concern and even scare in this regard in India. One of the reasons for this was an incorrect report in the media that the virus strain isolated from the current outbreak in the U.K. came from India. The concern is unwarranted because FMD is endemic in India and is generally prevalent over the country. The furore in the U.K. and Europe is chiefly because these countries have been declared to be FMD free by the Office International des Epizooties (OIE), the international body for monitoring the spread of animal diseases.

Of course, there are instances of outbreaks every year in various parts of India - an outbreak being when the number of affected animals in some village, or groups of villages, exceed the normal number. A recent outbreak in Punjab and Haryana, around the same time as the outbreak in the U.K., heightened the focus on FMD, particularly in the media.

The total number of FMD cases in the U.K. in the current outbreak is reported to be 322 (as of March 18). India has an animal population of about 450 million (200 million cows, 85 million buffaloes, 115 million goats, 20 million sheep and about 30 million pigs). In 1999, the total number of reported cases in India was 38,233. Of this bovine cases, which are the most numerous, were 35,574. In all, there were 940 (bovine) outbreaks during that year. According to the Department of Animal Husbandry and Dairying of the Ministry of Agriculture, the recent outbreak occurred in Gokulgarh vilage of Rewari district between February 12 and February 23. According to the Ministry, buffaloes and cattle numbering about 50 were affected in a total population of around 1,000. Subsequently, there were reports of an outbreak near Meerut, according to V.K. Taneja, Animal Husbandry Commissioner. A team has gone to study the situation. Initial reports said that the numbers in Meerut may be higher.

The outbreak is often seasonal, occurring mainly during October-November and February-April, because of increased agricultural activity, such as harvesting and sowing. Statistically, according to P.N. Khanna, a former scientist of the Indian Veterinary Research Institute (IVRI), Izzatnagar, in a given region an outbreak of the FMD can be expected to occur once in every four years. This is essentially because the natural immunity conferred by infection at a time lasts about three years.

CAUSED by a small virus, the disease is highly contagious and is transmitted even by wind across an area of over 20 to 30 km. Although humans are not susceptible, a person handling infected cattle can be a carrier of the virus. Unlike in the West, where it is easy to control the spread through strict quarantine measures, slaughtering and even burning, the Indian context is entirely different. Movement and mixing of animals (even in urban areas) and cattle bazaars are common here and can lead to widespread transmission. During outbreaks, however, such trade fairs are forbidden. Moreover, the dairy and meat industry being extremely important in the West, it is the concern over enormous economic losses owing to the disease that warranted burning. In India such measures would be unthinkable especially when it is known that the virus is not transmitted to man, that the disease is self limiting and that milk and meat are easily rid of the virus by simple measures such as treatment with caustic soda or citric acid.

The virus comes in seven distinct strains of A, C, O, Asia 1, SAT1, SAT2 and SAT3, of which the last three are confined to the African region. However, Khanna said that there were as many as 60 variants with minor "shift" and "drift" mutations. All the four non-African strains were found in India, of which the most virulent was the O type. This type was first isolated in India by the IVRI in 1990. This strain is referred to as the pan-Asian strain and this has since been isolated in several other countries. Disease caused by the O type is also the most widespread, accounting for about 80 per cent of the cases in India. However, for the last two years, no case of infection owing to the C strain has been found.

It was this pan-Asian O strain that was recently isolated in the U.K. by the European Referral Laboratory for FMD at Pirbright. According to the centre, the virus was isolated on February 19 from pigs in an abattoir in Essex. What has been stated is that the virus characterisation is similar to the Indian strain. However, there is no way of concluding that it went from India. In any case, since no milk or meat products from India are allowed to be exported to FMD free countries, the possibility of the virus having travelled from India seems remote. India does, however, exports meat to West Asia and South-East Asian countries. It is possible that the meat re-exported from there could have carried the virus. However, even that is unlikely because, according to Taneja, exported meat is deboned, deglanded and chilled. Under these conditions the virus does not survive. Moreover, ante-mortem and post-mortem of slaughtered animals is a must for meat export houses.

The death reports in the recent outbreak in the Punjab-Haryana region (about a dozen) were not owing to FMD. The deaths were the result of secondary infections caused by the general loss of immunity and most of these were found to be owing to the bacterial infection of haemorrhagic sceptecemia (HS), or Pasteurellosis.