Indian record

The certificate issued to India by the World Organisation for Animal Health. - BY SPECIAL ARRANGEMENT

Rinderpest probably came to India around the mid-18th century, and the country was officially declared free of it in 2006.

RINDERPEST was endemic throughout India until the mid-1950s, with about 8,000 outbreaks a year that affected on an average about 400,000 bovines, killing about 50 per cent of them. The mortality rate per 100,000 animals was 100 to 200. After sustained campaigns of mass immunisation and surveillance followed by diagnostics, serosurveillance and focussed vaccination efforts in endemic regions, India was finally declared rinderpest-free in May 2006 by the World Organisation for Animal Health (OIE).

The disease, according to medical historians, probably got introduced into India through the north-eastern route from Mongolia/China around the mid-18th century. Efforts to control it can be traced back to the establishment of the Indian Cattle Plague Commission in 1868. In 1871, the commission, headed by J.H.B. Hallen, carried out a detailed study of the murrain across the country based on farmers' reports and identified it as identical to the one prevalent then in Europe. Like elsewhere in the world, in India, the continuing wide prevalence of the disease and the impact it had on the agro-based economy led to the initiation of veterinary research in the country, with the establishment of the Imperial Bacteriological Laboratory in Pune (which now is the Indian Veterinary Research Institute at Mukteswar in the Kumaon hills) in 1889 and the Indian Civil Veterinary Department in 1891.

The only control measure available from the 1920s to the 1940s was the serum-virus simultaneous method, which had its limitations. Once the attenuated goat tissue vaccine (GTV), which gave life-long immunity, was discovered, its production was established at various centres in the country, and this proved to be greatly beneficial in controlling rinderpest outbreaks. However, owing to financial constraints and the lack of trained veterinary human resource, this could not be implemented effectively across the country. This resulted in continued heavy loss of livestock.

With the limited success of the GTV, the first rinderpest mass vaccination drive, called the National Rinderpest Eradication Programme (NREP), was launched in 1954 as a pilot project covering 18 districts of Andhra Pradesh, Karnataka and Maharashtra. In 1956-57, this became a full-fledged mass vaccination campaign with the aim of 80 per cent coverage of the cattle and buffalo population of the country (an estimated 215 million) within a period of five years except for Tamil Nadu, Karnataka and Kerala, which at that time were rinderpest-free. The results were encouraging, with the number of outbreaks declining from 8,516 in 1956-67 to 960 in 1960-61 and dropping further to about 300 in 1964-66.

With the introduction of the tissue culture rinderpest vaccine (TCRV) in the 1960s in other parts of the world, which required facilities for freeze-drying and cold chain maintenance, India quickly switched over to it and the coverage improved steadily, bringing down the incidence to about 140-160 a year. Indeed, the NREP played an important role in the success of the Green Revolution.

However, even as the disease was largely controlled in the northern, eastern, western, central and north-eastern regions, it surfaced in a big way in the southern States of Tamil Nadu, Karnataka and Kerala, where it prevailed unabated until 1974. Sixty to 80 per cent of the bovine population was immunised in these States, and several other strategies including enhanced rinderpest surveillance and containment mechanisms, vaccination of animals during transport and at cattle fairs, marking vaccinated animals, and putting in place inter-State and international border check posts, vaccination stations and vigilance units were adopted. As a result of these, the incidence came down from 1,960 a million to 12 a million during 1975-80.

However, the NREP seemed to be failing as the incidence again rose, to 22 a million during 1980-85 and to 43 a million during 1985-90, and it was soon realised that, notwithstanding the mass vaccinations, a much higher immunisation coverage was required just to maintain the status quo. In 1983, a task force on the disease was constituted, and it observed that only eight States were rinderpest-free and the distribution of the disease seemed random, with no immediate epidemiological explanation.

For example, while Tamil Nadu and Kerala reported an average of fewer than five outbreaks, Karnataka reported 48 and Andhra 116, with more than half of them in sheep and goats.

Infection among small ruminants had been on the rise since 1972, but apparently many people did not believe that the virus could exist in small ruminants. M.S. Shaila of the Indian Institute of Science, Bangalore, who has studied the virus extensively, used a molecular method of differential diagnosis and demonstrated unequivocally the occurrence of rinderpest in small ruminants.

Perhaps, this was one of the major epidemiological factors as to how rinderpest established such a stronghold in the southern States, said M. Rajasekhar, former head of the Project Directorate on Animal Disease Monitoring and Surveillance of the Indian Council of Agricultural Research (ICAR), in his 2002 review of the Indian rinderpest saga. Epidemiologically, he wrote, the virus was at large and remained at its best in establishing endemicity through a variety of susceptible hosts. A high-density ratio of small to large ruminants and the presence of highly susceptible exotic and cross-bred populations might have been [the] contributory factors.

According to Shaila, wealthy farmers around Bangalore who owned cross-bred cattle for maximum milk yield committed suicide after suffering huge losses during an outbreak.

Also, according to Rajasekhar, the Indian campaigns until then did not address the field-based operational problems of cold chain, mobility, quality of vaccines, extension education, post-campaign serosurveillance, diagnostic laboratory infrastructure and, above all, a time frame for ultimate eradication.

Seroconversion rates the rates at which specific antibodies to the virus antigen develop in the blood serum of a vaccinated population after a certain lapse of time were apparently very low in most States except for two which had 50 per cent rates. This, in his opinion, could have been because of poor vaccine quality control, either at the production stage or owing to cold chain failure, and even faulty vaccination in field conditions.

The task force recommended a reorientation of strategies with a time-bound programme of eradication within five years. According to Rajasekhar, by the late 1980s it became clear that RP outbreaks in the country had bottomed out to an irreducible level and a final thrust towards total eradication was necessary. However, four decades of mass vaccination was proving to be a major drain on the country's finances and veterinary manpower.

With the recommendations and support of the Food and Agriculture Organisation (FAO) of the United Nations, India signed a financial agreement with the European Union (E.U.) in 1989 for Strengthening of Veterinary Services for Livestock Disease Control in India. Following this financial support and with a stable and reasonably low rinderpest situation, India launched its final thrust against the disease in 1991 in the form of the National Project on Rinderpest Eradication (NPRE). Implementation began in May 1992 as part of the Eighth Five-Year Plan. The project adopted the OIE Pathway towards rinderpest eradication in 1993-94.

The project divided the country into four zones (A, B, C and D) on the basis of past rinderpest epidemiology and geographical contiguity. It became clear that the intermittent outbreaks recorded in the late 1980s were owing to the introduction of infected animals from southern India into the urban dairies of northern India, while the north-eastern region and off-shore islands remained rinderpest-free.

As a result of 35 years of mass vaccination, the endemic rinderpest situation in northern and central India was largely controlled. The institutionalised mass vaccination in the north gave way to focussed vaccination in southern peninsular India. Taking cognisance of Shaila's findings with regard to small ruminants, the NPRE began to vaccinate sheep and goats as well in southern India.

Zones A, B, and D were declared provisionally free from rinderpest disease during 1995-96 after the stoppage of vaccination in 1993-94. Zone C which comprised the States of southern peninsular India were declared provisionally free from rinderpest disease effective from March 1, 1998. The last outbreak occurred in India in September 1995. The project ran its full course up to July 31, 1998, after which the E.U. stopped supporting the project.

The generalised vaccination across the country was stopped on January 1, 1998, but a 30-kilometre vaccine buffer zone along the India-Pakistan border in Gujarat, Rajasthan, Punjab and Jammu and Kashmir was maintained with saturation vaccination until October 2000, after which an early warning and response system was initiated.

After the expiry of the E.U. funding, the project, which included serosurveillance and monitoring across the country, was funded entirely by the Indian government. The serosurveillance programme was based on a sampling frame, which ensured detection of even a single case of rinderpest in the population with a 95 per cent confidence level, to rule out hidden pockets of infection in the population. This was aimed at complete rinderpest eradication and was executed in three consecutive phases between November 2001 and October 2004.

After the submission of the relevant data and dossier on the Indian rinderpest situation, India was declared free from rinderpest disease on May 22, 2004, which constitutes the second stage of the OIE's three-stage process of accrediting a country as free from rinderpest. On May 25, 2006, on the basis of the final dossier submitted on August 22, 2005, India was declared free from rinderpest infection, the OIE's third and final stage of accreditation.

Since the Tenth Plan, the NPRE was merged with the centrally sponsored macro-management scheme Livestock Health and Disease Control as one of its components and is being continued with an annual budgetary allocation of about Rs.2-3 crore. Currently, India is maintaining a reserve of 2.5 million doses of TCRV at six vaccine banks across the country to meet any eventuality arising from a re-emergence of the disease.