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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Salmonellosis
Salmonella has two species- Salmonella enterica and Salmonella bongori. Salmonella enterica is divided into 6 sub species. They are divided into two groups- Typhoidal and Non-typhoidal. Non typhoidal serotype can be transferred from animal-human and human-human. This kind invades the gastrointestinal tract. Typhoidal serotypes are generally transferred from human-human and can be food-borne as well. These serotypes can cause typhoid fever and paratyphoid fever.
Salmonella spp. colonise in the large intestine of a variety of mammals. In canines, they lodge themselves in the distal part of the colon and mesenteric lymph nodes. Humans can get infected via faecal-oral route of transmission and develop diseases like gastroenteritis, enteric fever, bacteremia and osteomyelitis. Infected animals or humans can be asymptomatic and shed the pathogen for 6 weeks after being exposed.
This disease is also spread via undercooked meat, raw fruits or vegetables, unpasteurised milk and dairy products, raw or undercooked eggs. A person with inflammatory bowel disease or on medicines like steroids or with a travel history in an unsanitary conditions is more susceptible to this disease. Infants and children below 5 years and aged people above 65 years are also prone to this disease.
In humans-
It takes anywhere between 6 hours to 6 days for the symptoms to start showing.
- Fever
- Diarrhoea
- Nausea
- Vomiting
- Abdominal pain
Recovery happens with 4-7 days without treatment in most cases however some cases may need hospitalisation. Salmonellosis can be fatal if not rightfully paid attention to (in the cases where the infection is severe).
In animals-
It is uncommon in dogs and cats but they can be carriers of this bacteria. Some signs of infections include:
- Vomiting
- Diarrhoea
- Fever
- Loss of appetite
- Reduced activity
Diagnosis is based on clinical signs and bacterial culture. Feacal cultures can lack sensitivity. Repeated sampling is required to diagnose the carrier state of an animal. Other methods used are phage-typing, PCR and lateral flow immunoassays. Serological tests used to identify specific antibodies are also available to diagnose Salmonella.
Animals should be adopted/ purchased only from known sources. They should be quarantined for at least a week before allowing them to interact with other humans and animals. Some live vaccines are available for use in swine and fowl however none are available for humans.After interacting with animals, try to wash your hands thoroughly. Sanitize your hands when soap and water are not available. Try to clean your pet’s areas and cages as frequently as possible. Avoid eating or drinking around high-risk animals.