The A to Z of Zoonoses

Express News Service

We all gasped in fear, religiously used sanitizers, doubled-masked and even triple-masked and strictly maintained social distance, during the COVID-19 outbreak. The initial fear was the result of ignorance of a novel virus.

While the debate on the origin of COVID-19 pandemic as a zoonoses is an ongoing one, it is important to be aware of other zoonoses, diseases spread from animals to humans and vice-versa, on this World Zoonoses Day.

“It is important to study zoonoses to strengthen surveillance for early and effective diagnosis. While treatment for each disease varies accordingly, understanding the precautions helps us in timely containment and prevention of diseases,” suggests Dr Shekhar Kumar Niraj, IFS, first Director of Advanced Institute for Wildlife Conservation (AWIC).

With inputs from Dr Shekhar, here is a curated list of zoonotic diseases listing the carriers of infection, symptoms and precautions. 

Rabies

Carriers of infection

Dogs are the main carriers of rabies, but wild animals like foxes, racoons, skunks, mongooses and coyotes are the primary carriers of sylvatic rabies. 

Precautions

Since the rabies virus enters the human body through a bite or scratch, it is imperative to be cautious around animals. Period testings of both the animals and those in contact with the animals should be initiated.

Clinical symptoms

• Pain and tingling sensation in the affected limb especially close to the bite site may be the first symptoms to manifest. The most well-known symptom of this condition is hydrophobia — fear of water.

• In animals, rabid cats exhibit severe aggression, high levels of sensitivity to touch or voice, excessive salivation, and they may even try to attack people or dogs. Rabies in cattle causes irregular motions of the posterior extremities, frothy yellow froth coming from the mouth, and a reduction in milk production.

Carriers of infection

Rodents, foxes, wild cats, and rabbits

Clinical symptoms

Fever, tenderness and pain in the abdominal and lumbosacral muscles, and severely tender, hemorrhagic tendencies are also present in some cases.

Precautions

As a preventative strategy, hygiene practices include avoiding both direct and indirect human contact with animal urine. Workers in marshy areas should be urged to wear rubber shoes and gloves, and avoid direct contact with hazardous water or mud.

Kala-Azar or visceral aniasis

Carriers of infection

The illness is spread by the bite of infected sandflies. The flies thrive in moist, organically rich soil close to mud huts and cow barns, and the disease transmission is most prevalent during the rainy season.

Clinical symptoms

The patient exhibits malaise, weight loss, anorexia, cough, diarrhoea, and fever as first symptoms. It is also typical for the skin of the face, hands, feet, and belly to darken.

Precautions

Continuous surveillance and disinfecting your habitat are the control measures.

Rickettsial Diseases

Precautions

There isn’t a vaccination to protect against infection, so children and adults should be cautious engaging in bushwalking and camping. People who can’t avoid contaminated areas should wear protective gear and cover up with miticide-treated clothing.

Brucellosis

Carriers of infection

Goats, sheep, cattle, buffalo, and pigs 

Clinical symptoms

Some individuals experience a brief, acute sickness that passes quickly, while others experience a persistent fever with numerous relapses.

Precautions

Avoid dairy products that haven’t been pasteurised. In high-risk workplaces, use safety precautions.