Z O O N O T I C D I S EA S E S: W H Y I T I S I M P O R T A N T F O R U S T O K N O W
Health is wealth so goes the saying. In other words it symbolizes human wellness as well as of a nation. Health and disease are two facets of life. The former influences wellbeing while the latter reverses it. In their life time men and animals equally suffer from variety of infectious and noninfectious diseases. Majority of diseases in men and animals are infectious. Among noninfectious diseases lifestyle and deficiency diseases in humans are important. While rich suffer from lifestyle diseases the poor and the underprivileged suffer from metabolic disorders mainly due to malnutrition. Apart from these humans also suffer from zoonotic diseases meaning animal diseases which jump to humans because of ‘Human-Animal- Ecosystems Interface’ for several thousand years or likely to cross back in future. One such classical example is HIV of chimpanzee which has mutated to become a human virus, a cause of sexually transmitted AIDS. Likewise many believe that nCorona virus (COVID-19), an animal virus, has become a human virus – the cause of current pandemic worldwide. However, cases have been reported when COVID-19 has crossed back to animals like tiger, dogs and cats in the USA, Hon Kong, and Brussels etc. It may be termed as reverse zoonoses. We have to be extra careful if it happens in a large scale. We have to learn lessons about the frails of zoonotic diseases especially regarding the viral diseases. This is the topic of discussion in the emerging situation.
https://www.pashudhanpraharee.com/common-zoonotic-diseases-transmitted-by-cattle/
The role of animals in transmission of infectious diseases to man is well recognized. Animals are known to harbor enabling pathogens to survive and transmit to other hosts so as to maintain continuity. It is known that humans suffer from infectious diseases caused by as many as 1415 organisms including 217 viruses and prions, 538 bacteria and rickettsia, 307 fungi, 66 protozoa and 287 helminthes. Of these, 61% originated from animals and many of them have established in humans. The viruses being obligate parasites cannot survive without a living cell/host. Most of them, if not all, have the capability to mutate which in turn can become more virulent or less virulent or even non-pathogenic. Emerging diseases, numbering about 175, have created serious health problems in recent years. Notably of these emerging diseases 132 (75%) are zoonotic. Therefore, zoonoses arising out of viral infection are seriously viewed today in the domain of public health care dispensation, although it often went unrecognized in the past, as it gained importance because of its propensity to infect large human population with greater severity. The severe acute respiratory syndrome (SARS) and COVID-19 pandemic are few illustrations.
Other factors that influence higher incidence of zoonotic diseases may be attributed to change of food habits from vegetarian to non-vegetarian diets of animal origin either half cooked or raw as in China, Western countries, and in NE states India. Among the parasitic zoonosis intermediate stage of human tapeworm infestation in pigs (measly pork) and hydatidosis due to consumption of half cooked meat men get infected. The growing ingression of human habitation to animal habitats brings about the human wildlife interface closer. Further more intensive farming practice combined with factory farming could accentuate the incidence and variety of zoonotic diseases. The rapidity of zoonotic disease spread may be due to faster travels of people, international trade in animals as vehicles of transmission. For instance look at the mammoth migration of people in the current Coronavirus. High mobile birds and bats which fly fairly long distances carried Nipah and bird flu viruses to disease free zones. There is fair evidence that measles, small pox, influenza (including bird flu, pandemic flu), Ebola, Marburg (Filoviruses), west Nile disease, mad cow disease and diphtheria had animal origin. In summation it can be said all infections classified as zoonoses can exist only where and when animals are present. Significantly over 200 zoonoses have been reported and are known to exist for many centuries. Of them 50 are from rodents, 32 from dogs, 30 from cats, 27 from pigs, 23 from cattle, 17 from sheep and goats, 13 from horses, 19 from birds, 9 from bats and 19 from fishes. Armadillo and pangolin are suspected to have transmitted nCoronavirus. Animal to human diseases kill 2.2 million people worldwide each year. Therefore, the magnitude of zoonoses can be well imagined.
No reliable information/data on zoonotic disease status in India and Odisha is available due to poor public health infrastructure and no vestiges of veterinary public health. For example two prominent zoonotic diseases can be cited out of many. Anthrax, primarily a disease of ruminants, is reported from Odisha, northern Andhra Pradesh, south western West Bengal, Chhattisgargh and Jharkhand. The badly affected districts of Odisha are Koraput, Sundargarh, Rayagada, Kendrapada, Cuttack, Balangir, and Kandhamal etc. Humans suffer when they eat the flesh of infected animals or handle the carcass. Socio-economic condition forced them to consume meat of dead animal and also because of centuries of public apathy and ignorance. Dog mediated rabies is another matter of major concern. Following dog bite improper wound management and failure/delay in immunization could invariably lead to death. This is a disease which is 100% preventable if immunization is carried out in time otherwise 100% fatal. Children below 15 years and economically disadvantaged persons are most vulnerable as medical facility for post exposure free immunization is not available. Besides stray dog menace is ever increasing in absence of universal population control program for dogs and absence of statutory law for compulsory vaccination of dogs. Other examples are bovine tuberculosis, brucellosis that causes abortion in cows, Salmonella and E. coli infections, Streptococcal sepsis, plague, bird flu, swine flu, Foot and Mouth Disease (FMD) commonly encountered among cloven footed animals besides being an economic disease, Nipah fever, dengue fever, Ebola, Lyme disease, Japanese encephalitis (reported in Malkangiri district in 2016), toxocariasis, and ring worm etc.
Prevalence of zoonotic diseases in human population as a part of community medicine is not taken seriously except perhaps for rabies in Odisha. Investigation, if taken up at any time, cannot become successful without the help of veterinary professionals. For example we do not yet know the status and ill effects brucellosis amongst dairy farmers and their families though the disease is prevalent among village cattle. It can lead to sterility, abortion, orchitis, undulant fever, and joint pain etc., in humans. Therefore, the government of India has launched a flagship program for eradication of brucellosis to safe guard dairy cattle. Many of the zoonotic diseases are country specific but no wonder they can invade India at any time considering increased international movement of human traffic and trade.
This significant aspect of public health related to zoonoses is seldom given any importance in India even when interventions are intended and planned exclusively for human population though it deserves a multidisciplinary approach. For any crisis management or formulation of state policy in any sector the doctrine has always policy in any sector been that babus know the best. In this context it should be borne in the minds of administrators, policy makers, planners, and the end users in particular that human and animal health problems are intrinsically linked due to variety of reasons and that they are not confined to any specific region nor do they respect international borders though the issues may greatly vary in countries in economic transition. For management of zoonotic diseases joint endeavour should in place linking medical and veterinary professional for public good.
India does have a central institution like Centre of Disease Control and Prevention (formerly known as NICD) under the central government without clear cut programme on zoonotic diseases respecting ‘One Health’ concept of the World Health Organisation (WHO) and World Organisation for Animal Health (OIE). Indian Council of Medical Research (ICMR) and Indian Council of Agricultural Research (ICAR) have jointly taken up an ambitious project to establish a National Institute of Zoonotic Diseases in Nagpur. Hope it will come up in near future. Sadly in India people prefer to work in isolation until lately even during a catastrophe like COVID-19 pandemic. All that we have is Indian Council of Medical Research which monitors human health problems and issues guidelines with no inclusive approach in sight. Unfortunately there is no independent Council of Veterinary Research at national level though Indian Council of Agricultural Research regulates researches in veterinary science. It is time to bring together scientists, diseases detectives, laboratory men, physicians, and veterinarians to prevent those illnesses to protect the health of the people, animals, and our environment. The latter is most important.
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Dr. Harekrushna Pradhan, Ph. D.,* & Dr. D. N. Mohanty, M. V. Sc.** Email- dnmohanty2018@gmail.com Mobile No. 9437113581
*Founder Director of High Security Animal Disease Laboratory, Bhopal & ex-WHO, Consultant since deceased ** Retired Joint Director, Odisha Biological Products Institute, Bhubaneswar.
The article was published in Orissa Today in June, 2020
