Bacterial Zoonoses
A bacterium is a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organised nucleus. The diseases caused by bacteria are known as bacterial diseases.
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Tuberculosis
Tuberculosis is a potentially severe infection caused by the bacteria Mycobacterium tuberculosis, M. bovis, M. canis, M. microtii, M. africanum that affects the lungs. It can also spread to other parts of the body like brain and spine. From all these strains M. tuberculosis and M. bovis are highly pathogenic. These bacteria infect both animals and humans but animal to human transmission of this disease has not been observed. It is interesting to note that human to animal transmissions have taken place and hence this disease is a type of anthropozoonosis. Canines are usually resistant to the M. tuberculosis infection, but cases have been reported from dogs who have ben living with affected owners. This is a long infection and recovery takes months.
The only reservoirs for M. tuberculosis are humans. However, this bacteria has a wide host range and has been detected in fishes, reptiles, birds and other mammals. Tuberculosis in humans is normally transmitted by inhalation. A source releases infective agents in the environment that survive in the air and are inhaled by susceptible people. People with weakened immunities and HIV are more susceptible to this disease.
Humans can get an infection from M. bovis (this bacteria mainly attacks cattle) mainly by intake of contaminated dairy products. Transmission by direct contact or droplets is also possible. This infection does not transmit from human to human.
Pet animals like dogs and cats are at less risk of this disease as they are resistant to these bacteria. Cats are more resistant than dogs. They are not likely to be spreaders of this disease as well. Most canines get this disease from humans or cattle and dog-dog transmission does not occur.
In humans-
- Active cough for more than 3 weeks
- Chest ache
- Bloody cough
- Exhaustion
- Chills and night sweats
- Fever
- Loss of appetite
- Weight loss
In animals-
- Weakness
- Weightloss
- Fever
- Coughing
Isolation of active TB cases is important. Covering of math while coughing and sneezing is important in preventing not only TB but also many other diseases. Avoid spending time in crowded places where TB is common.
BCG vaccine is available for children under 10 years where tuberculosis is common.
- Follow a strict handwashing regime if you have pets at home.
- If you have been bitten by a dog or a cat, wash it immediately with soap and running water.
- If you develop any symptoms 10-14 days after an animals bite, contact your physician without any delay.
- Avoid contact with pet saliva of broken skin and mucus membranes.