Short Feature

SHORT FEATURE

Vishal Rai, Ashok Kumar, Mukesh Bhatt, Ajay Kumar Yadav, Sushmita Nautiyal & Neha Thakur

Rare zoonoses of viral etiology (The image is for representational purpose only)

OONOSES, diseases and infections that are naturally as it crosses the species barrier with difficulty and with transmitted between vertebrate animals and humans, little effect, yet it is considered zoonotic due to a few of the Zhave been posing a great challenge worldwide. In documented human cases. 2001, it was estimated that 61% out of the 1415 microbial Its incubation period in humans ranges from 2-6 days. diseases affecting humans are zoonotic. Among emerging The disease in humans is usually mild and self-limiting. It is infectious diseases, 75% are zoonotic with wildlife being one manifested in the form of fever, sore throat and development of the major sources of infection. of uncomfortable tingling blisters on the hands, feet and in Of course, the figures have changed drastically now mouth, including the tongue. Affected individuals usually owing to the emergence of new infections in the past two recover shortly after the last blister formation. Human to decades. Viruses are one of the major contributors of human transmission has not been reported yet. Human zoonotic diseases, with some causing life-threatening ailments infection from pasteurized milk has not been reported and in humans. A large fraction of animal viral pathogens are the Food Standards Agency considers that the disease has no associated with disease conditions in humans, which are implications for the human food chain. known to the masses. However, a small fraction of such pathogens is involved in rare diseases in humans. These Newcastle Disease (ND) conditions are not known to many. ND is one of the most economically devastating diseases of poultry. Chicken is the most susceptible to infection, with Foot and Mouth Disease (FMD) affected flocks experiencing morbidity and mortality rates FMD, caused by Foot and Mouth Disease Virus (FMDV) up to 100%. It is caused by avian paramyxovirus type 1 of the genus Apthovirus under Picornaviridae family, is a (APMV-1), member of the genus Avulavirus in the family highly contagious disease affecting all cloven-footed animals. Paramyxoviridae. Seven serotypes of the virus have been recorded, viz. O, A, ND has been reported in humans following exposure to C, SAT1, SAT2, SAT3, and Asia1. large quantities of virus. Laboratory workers and vaccination The number of human FMD infections is considered crews are the most susceptible to infection. Infections in insignificant when compared to the devastation they have poultry workers are rare and handling or consuming poultry caused in the animal world. Infections are rare in humans products is not considered a risk factor.

July 2020 | Science Reporter | 23 It is manifested as a mild, self-limiting influenza-like factor for human infections, which leads to the development disease in humans, with clinical signs of fever, headache, of painful scabby sores on the hands and arms. The lesion in malaise and conjunctivitis. Any form of contact with birds human is referred to as milker’s nodule. should be avoided at the time of conjunctivitis as the virus is shed for 4-7 days in ocular discharges. Conjunctivitis Vesicular Stomatitis usually resolves rapidly without treatment. It is suggested Vesicular stomatitis is a viral disease of cattle, pigs and that APMV-1 can cause serious opportunistic infections in horses caused by members of the genus Vesiculovirus under severely immunosuppressed individuals. Rhabdoviridae family, producing blister-like sores on the mouth and feet of infected animals. People who are in direct Zoonotic Orthopoxviruses contact with infected animals develop flu-like symptoms and Viruses of zoonotic importance in the genus Orthopoxvirus occasional blisters on their hands and in the mouth. According of family Poxviridae include Buffalopox Virus (BPV), to some authors, conjunctivitis or cheilitis may be observed Camelpox Virus (CMLV) and Monkeypox Virus (MPV). as an early sign of infection. Acute nausea, vomiting and Buffalo Pox Virus (BPV) is the cause of buffalopox, a diarrhoea, in addition to nonspecific flu-like signs have been contagious viral disease, which mostly affects buffaloes but described in one affected individual. Affected people usually rarely cows and human beings. It was isolated for the first recover within 4-7 days without complications. time in 1967 in Northern India and has been continuously reported from the states of Uttar Pradesh, Rajasthan, Andhra Other Zoonotic Viral Infections Pradesh, Gujarat and Karnataka. Milkers are susceptible to Human B Virus Infection is a serious zoonotic hazard caused infection and accidental exposure to the virus is accompanied by macacine herpesvirus 1/B virus/cercopithecine herpesvirus by the development of pox-like local lesions on the hands, 1. This infection is common in all macaques used in forearms and forehead with symptoms of general malaise, biomedical research. Usually, this infection is asymptomatic fever and axillary lymphadenopathy. or causes mild disease in animals and is transmitted to Camelpox is a disease of socioeconomic significance susceptible humans through bite, scratch or mucosal contact. in African and Asian countries with indigenous camel The incubation period can be as short as two days to as long population. Earlier, it was thought that the disease is only as 2-5 weeks. Vesicles, pruritus, and hyperesthesia at the site confined to camels. However, after the confirmation of the of bite are often the first clinical sign, followed by ascending first human cases of camelpox in India, it is now considered paralysis, encephalitis, and death. a zoonotic disease. Clinical manifestations in humans include Borna disease in horses, sheep, and other domestic eruption of papules, vesicles, ulcers on fingers and hands and mammals is caused by Borna disease virus 1 (BoDV-1) of the finally scabbing. family Bornaviridae. Until recently, its status as a zoonotic There were reports of rash-causing illnesses from agent was a matter of debate in the scientific community. various parts of Western and Central Africa at the time when However, a recent study has confirmed that this virus affects smallpox was eradicated from those countries. Investigations humans. Humans can get infected by direct contact with by WHO from 1970-86 showed that the causative agent was persistently infected animals. The study reported that humans Monkeypox Virus (MPV) with a case fatality rate of up to exhibit symptoms of fever, headache and confusion, followed 10-17%. After the WHO campaign, notable monkeypox by various neurological signs, deep coma, etc. Some of the outbreaks were those from the Democratic Republic of Congo patients develop fatal encephalitis when affected by this virus. in 1996/1997 and 2001-2004, and Southern Sudan in 2005. Semliki forest virus of the genus Alphavirus of Togaviridae is considered a zoonosis, with predominant signs Clinical signs and symptoms resemble those of smallpox, of headache, fever, myalgia and arthralgia and rare signs such as a generalised pustular rash, lymphadenopathy and of abdominal pain, diarrhoea, and conjunctivitis in affected fever. Monkeypox in humans occurs as a result of direct humans. contact with wild animals, such as squirrels and monkeys Zoonotic diseases are here to stay. Therefore, basic killed for food. Rodents and nonhuman primate species protective and hygienic measures must be taken while maintain the virus in nature. handling animals, even if the animals are apparently healthy. Farmers at the field level must also be made aware. Creating Zoonotic Parapoxviruses awareness about the potential threats would help in striving Two parapoxviruses have been described as zoonotic, i.e. orf towards the goal of “One Health” which is going to be virus and pseudocowpox virus. Orf is a disease of sheep and future of healthcare in the world after the recent COVID-19 goats, human infections are acquired from affected animals. outbreak. With an incubation period of 2-4 days, the disease in humans is characterised by the development of macular lesions, Vishal Rai, Ashok Kumar and Mukesh Bhatt are at the ICAR-Indian papular lesions, and large nodules resembling papillomas, Veterinary Research Institute, Izatnagar, Bareilly, U.P.-243122; fever, lymphangitis and rarely blindness. The lesions persist Ajay Kumar Yadav is at the ICAR-National Research Centre on Pig, for 4-9 weeks, followed by healing without leaving scars. Rani, Guwahati; Sushmita Nautiyal is at the ICAR-Indian Veterinary Pseudocowpox is a disease of cattle that is characterised Research Institute, Mukteswar, Nainital, Uttarakhand-263138 and by the presence of small raised sores and scabs on the teats and Neha Thakur is at the Lala Lajpat Rai University of Veterinary and udders. Direct contact with infected cows is the predisposing Animal Sciences, Hisar, Haryana-125001, Email: [email protected]

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