Zoonoses are infectious diseases (virus, bacteria and parasites) that can be spread from animals to humans, and vice versa. Zoonoses can spread from direct contact with animals or indirectly. They can be vector-borne or food-borne. Zoonotic diseases are very common, for example, tick-borne encephalitis and borreliosis. Many food-borne infectious diseases like salmonella, Yersinia, botulism or campylobacter are also zoonoses.
In the past 20 years, 70% of the emerging diseases have been found to be zoonotic in nature and about 300 diseases are common to man and animals. Bubonic plague (Black Death), typhoid, malaria, gastrointestinal and sexually transmitted diseases have caused havoc in modern times and interestingly all have animal origins. In recent times, AIDS/HIV, mad cow disease and bird flu have caused major health epidemics.
The problem of zoonoses is compounded on account of poor healthcare infrastructure in the state of J&K. Zoonoses affect humans in a variety of ways. The diseases cause illness or deaths but also monetary losses in the form of cost of drugs and physician’s fees, loss of wages, and reduced work efficiency, medico-legal complications, and public scare. In animals, the major impact relates to loss of production and loss of breeding efficiency.
In Kashmir, we can boast of the best tertiary healthcare system but our primary health services are rudimentary, lack infrastructure and equipment. The technical network with respect to disease surveillance is limited and statistical measures are not evolved enough in disease surveillance programmes. Recently the state of J&K has been hooked to the National Disease Surveillance Network, which envisages interconnectivity between different tiers of the network for instant data collection, interpretation, and timely remedial measures.
Factors affecting the probability of zoonotic occurrence include: duration of illness, virulence of the pathogen, stability of the agent in a given environment, density of animal and human population in a locality, animal husbandry & agricultural practices, presence of vectors and rodents, technological and economic diversification, urbanisation and mobility of humans, livestock and livestock products, inadequacy of diagnosis and other health services, genetic component of pathogens and route of transmission of the diseases.
Economic development (dams, roads and deforestation) and rapid social development have also provided opportunities to zoonotic pathogens to emerge and spread rapidly in the human as well as animal populations. Moreover, indiscriminate use of antibiotics, insecticides and other chemicals has led to an alteration in the existing microbial ecology. Greenhouse effect may change the density pattern of the microbes and vectors of the transmissible diseases. Increased densities of ticks and other insects facilitate rapid spread of arthropod-borne infection. Higher rodent populations have enhanced the prevalence of leptospirosis and salmonellosis.
To assess the ability for combating infectious/zoonotic diseases in human beings, it must be kept in the mind that most of the diseases are fundamentally diseases of vertebrate and invertebrate wildlife. Awareness of veterinary knowledge has gradually led to the concept of “one medicine” wherein experiences of physicians, veterinarians and other medically-oriented scientists are shared. Rudolf Virchow, the father of modern pathology, said that “between animal and human medicine there is no dividing line nor should there be. The object is different but the experience obtained constitutes the basis of all medicine.” So, advanced veterinary expertise and control strategies are important in containing zoonotic infections.
Apart from the allopathic system of medicine, alternate systems of medicine are also exploited in infectious disease control. Communication and information technologies and other traditional media have been effectively used to bring about behavioural changes with respect to communicable diseases like HIV and sexually transmitted diseases. Therefore, management of zoonotic diseases in a well-organised surveillance system is an essential component of disease control and diagnosis of zoonotic diseases in animals and men. Different forums are associated with the issue of combating infectious diseases at international level. The World Health Organisation (WHO) and the Food and Agricultural Organisation (FAO) are the main global organisations concerned with control of infectious diseases.
—The writer is a student of Zoology at Central University of Kashmir. [email protected]