When we talk of veterinary public health very few people know that such a subject exists because it has never been given importance in our country unlike medical public health. Western countries and Japan recognize the role of veterinary public health in delivery of health services to their people.
We may consider the role of veterinarians in the context of present Japanese Encephalitis (JE) outbreak in Malkangiri district. Perhaps, people are not aware that many animal diseases are transmissible to man which are named as zoonotic disease. The zoonotic diseases too are public health hazards. JE can be considered as one of such diseases because it is transmitted from pigs to humans through mosquito bite.
JE virus does not cause any appreciable harm in pigs except abortion in pregnant sows. In this backdrop, large scale death in infants in Malkangiri district due to JE is a concern for both medical and veterinary public health. JE is a viral zoonotic disease of great consequence and has the potential of spreading to neighbouring regions of Koraput district and other districts.
Presence of a large pig population, which is livelihood for many poor people, has created panic in the areas where JE is yet to be reported. In certain areas people have resorted to violence and attacked a certain section of people who traditionally rear pigs exclusively for their livelihood. They are commonly known as ‘Ghoosuria’ -a nomadic type- in coastal belt.
These people have no other sustainable livelihood. It is suggested in some quarters that this particular community should change over to sheep and goat rearing. It is a matter of debate as it is easier said than done. The ‘Ghoosuria’ community is unlikely to accept this suggestion and give up age-old traditional practice.
However, the people who rear pigs in Malkangiri district are not nomadic type and lead a different life style. Through ages they have become familiar with a husbandry practice evolved by them alone without looking for any Government support. Further, keeping of a particular type of domestic animal for livelihood purpose is dependent upon its economic viability. However, social scientists have some role to play for a change over in husbandry practice.
JE was first reported from Japan in 1871 from which it derives its name. The virus belongs to the family Flaviviridae and genus Flaviivirusa. It is pandemic in eastern and southern Asia including India, Pakistan, Nepal, Bangladesh, Myanmar (Burma), Thailand, Malaysia, Indonesia and China etc. JE, unlike many mosquito-borne diseases, requires an amplifying host.
This is an important and critical factor in the epidemiology of human JE and influences the containment and control programme. In Asia, pigs are considered to be the most important amplifying host, providing a link to humans through their proximity to human settlements apart from bats and water birds such as storks, herons, egrets and other birds- being other most important hosts on whom we have least control.
Importantly, pigs are also the reservoir of JE virus. Man is an incidental and dead end host. Therefore, it is logical to conclude that pigs are intermediary in transmission of JE virus and presence of pig population is considered critical in JE epidemic situations. luckily man to man transmission does not occur. JE virus infection in other domestic animals does not result in high viraemia and hence, they are not expected to transmit the virus to humans. The same phenomenon is true for human beings. Many mosquito species of genus Culex are responsible for transmission of JE virus.
Most infections of JE are asymptomatic, but if clinical illness develops, it causes significant morbidity and mortality in children in the age group of 3 to 6 years. The disease usually occurs in summer and autumn (May to October). It is postulated that bird migration, certain irrigation projects, stagnant water in paddy fields, animal smuggling and global warming etc., provide congenial environment for epidemiological progression of JE.
The epidemiological scenario in Malkangiri district falls into this pattern though infants below 3 years have reportedly died. Apart from death, half of the survivors are likely to suffer from severe neuropsychiatric disorders. Recovery usually leaves serious behavioural and neurological sequelae, which may have immense societal impact in view of inadequacies in health services of Odisha coupled with extreme poverty in the endemic zones of Malkangiri district. In such situations, the poverty stricken people need a humane approach with healing touch.
The veterinarians have a supplementary and complementary role to play. They could help public health machinery by identifying the presence of JE virus in pig populated areas by sero-surveillance so that advance precautionary measures could be adopted by appropriate Government agencies. Interestingly, JE was reported in 2012 and 2014 in Malkangiri area but it appears that no contingent action plan was thought of to combat in case of its re-emergence in future.
What can we do to combat Japanese encephalitis (JE): (1) A firm regulatory policy with guidelines should be in place to contain and control JE epidemics in endemic areas; (2) A comprehensive sero-surveillance exercise should be undertaken to determine quantitative estimation of JE virus in pig population of Odisha and mapping of likely endemic zones on the basis of such data to obtain an epidemiological picture and a road map is drawn up to combat outbreaks of JE in future; (3) linkage with College of Veterinary Science and Animal Husbandry, Bhubaneswar and Indian Veterinary Research Institute, Izatnagar (UP) in all such matters for technical guidance; (4) Segregation of pigs at a distance of 3 to 5 km from human dwellings in epidemic situation because infected mosquitoes have the ability to fly up to 3 to 4 km; (5) Quarantine measures to be adopted with restriction on animal movement, (6) Sale of pigs in hats and pork publicly should be stopped; (7) Regular fogging of human dwellings and housing facilities of pigs (pig box) because mosquitoes feed on swine and human beings during dusk and evening. It would be desirable to fog the areas during feeder hours repeatedly to breach the transmission cycle of JE virus as far as possible; (8) A comprehensive and effective awareness package should be developed, keeping in view the level of literacy, acceptance of new ideas, and socio-economic condition etc; (9) Clearing of bushes around human dwellings as well as pig housing facilities to keep the surrounding and environment clean to reduce the vector population; (10) All the ditches and shallow places should be filled up to prevent accumulation of water which otherwise may become suitable breeding ground for mosquitoes; (11) Use of medicated mosquito nets by the population at risk; (12) Creation of awareness amongst pig farmers with the help of other line departments by mobilizing the youth brigades (National Social Service wings of educational institutions), Krushi Vigyan Kendras of OUAT, NGOs, paramedical workers, grass root veterinary workers and Youth Red Cross volunteers etc. with periodic review to assess the success of awareness campaign. Best campaigners should be rewarded; (13) Immunisation of pig population and children; (14) All the vehicles entering or exiting the endemic areas during epidemics should be fogged at entry and exit points because of their propensity to carry the infected mosquitoes inadvertently to JE free zones.
(Dr Mohanty and Dashsharma are life Members of Indian Red Cross Society, Odisha State Branch, A/E-192, VSS Nagar, Bhubaneswar; 9938537600)