Animal-to-Human Infectious Diseases: list of Animal-to-Human Infectious Diseases

Origin of Animal-to-Human Infectious Diseases

It is important to understand how infectious diseases spread from animals to humans so that outbreaks can be avoided and managed. Several factors contribute to the spread of zoonotic diseases, including:

A. Cross-Species Transmission

• Genetic mutation: Zoonotic diseases often arise when pathogens undergo genetic mutations that allow them to cross species barriers.

• Environmental change: Human activities, such as deforestation and climate change disrupt animals' natural habitats, bringing humans into closer contact with animals and their pathogens.

B. High-Risk Animal Species

• Reservoir hosts: Some animals are known as reservoir hosts. These animals carry pathogens without showing symptoms, making them potential sources of infection.

• Domesticated Animals: The proximity of humans to pets further facilitates the transmission of diseases.

list of Animal-to-Human Infectious Diseases

1. Zoonotic Influenza (H1N1)

• Origin: This disease is caused by pigs. Its transmission to humans occurs through close contact with infected pigs.

• Transmission: Human-to-human transmission can lead to global influenza outbreaks.

2. Ebola Virus Disease

• Origin: It originated from bats, and is transmitted to humans through consumption of contaminated wild meat.

• Transmission: It is transmitted through direct contact with the blood or bodily fluids of infected persons.

3. Severe Acute Respiratory Syndrome (SARS)

• Origin: Bats are considered its primary reservoir and civets act as intermediate hosts. This virus spreads to humans through civets.

• Transmission: Human-to-human transmission of this virus occurs through contact with infected respiratory droplets.

4. Middle East Respiratory Syndrome (MERS)

• Origin: This virus is mainly found in camels. Its transmission to humans occurs through the consumption of camel products or coming in contact with them.

• Transmission: Human-to-human transmission occurs during health care.

5. HIV/AIDS

• Origin: Human immunodeficiency virus (HIV) originated from simian immunodeficiency virus (SIV) in non-human primates.

• Transmission: Transmission to humans usually occurs through unprotected sexual contact, blood transfusions, or sharing contaminated needles.

6. West Nile Virus

• Origin: The primary reservoir of this virus is birds. Mosquitoes act as carriers of this virus to humans.

• Transmission: The primary mode of transmission of this disease to humans is mosquito bites.

Read also: Malaria 

7. Lyme Disease

• Origin: The disease is caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bites of infected black-legged ticks.

• Transmission: Ticks carry the bacteria through small mammals, such as rodents.

8. Q Fever

• Origin: This fever is caused by the bacterium Coxiella burnetii, found in domestic animals such as cattle, sheep, and goats.

• Transmission: It is spread to humans by breathing in infected dust particles.

9. Anthrax

• Origin: The causative agent of this disease is Bacillus anthracis. It spreads to humans through contact with infected animals or their products.

• Transmission: Transmission occurs by breathing infected air, swallowing anthrax spores, or coming into direct skin contact.

10. Rabies

• Origin: This virus is usually spread through the saliva of infected animals, such as dogs, and bats, and mammals such as raccoons.

• Transmission: It is spread by the bite or scratch of an infected animal to a human being.

Read more: Rabies

11. Brucellosis

• Origin: It is caused by bacteria of the Brucella genus. This bacteria is often found in domesticated animals such as cattle, sheep, and pigs.

• Transmission: In humans, it occurs through contact with infected animals or consumption of contaminated dairy products.

Understanding the diversity of animal-to-human infectious diseases is important to implement effective prevention and control measures.

Transmission mechanisms and risk factors

A. Direct Transmission

1. Contact with infected animals: It is spread to humans through direct physical contact with infected animals or their body fluids.

2. Consumption of contaminated products: Zoonotic infection occurs through humans' direct consumption of undercooked meat or unpasteurized dairy products.

B. Indirect Transmission

1. Vector-borne transmission: Some diseases spread to humans through vectors, such as mosquitoes or ticks, which receive the pathogen from animals.

2. Environmental contamination: Pathogens released by animals into their environment contaminate water sources and soil, allowing the infection to spread to humans.

C. Occupational and recreational exposures

1. Agricultural workers or health care professionals: Humans are directly exposed to zoonotic diseases through handling livestock or through contact with animal waste and, in veterinary medicine, through direct contact with infected animals or their samples.

2. Outdoor enthusiasts: Individuals who hike, camper, or otherwise engage in outdoor activities may be exposed to environments where zoonotic vectors (for example, ticks) are prevalent.

3. Pet owners: Those whose pets have contact with wildlife can be carriers of zoonotic pathogens. In such a situation, they easily infect humans.

Read also: Tapeworm

Prevention of animal-to-human transmission diseases

A. Surveillance and monitoring

1. Early detection: Establishing robust surveillance systems helps detect potential outbreaks at an early stage.

2. One Health approach: Adopting a “One Health” approach that integrates human, animal, and environmental health is critical for comprehensive disease surveillance.

B. Education and Awareness

1. Public awareness campaigns: It is necessary to educate people about the risks associated with close contact with animals and consumption of certain animal products.

2. Training for health care professionals: Health care professionals should be trained to recognize and manage zoonotic diseases to be able to prevent them.

C. Regulation and Control Measures

1. Strict animal trade regulations: Enforce rules on international and domestic trade in animals that help prevent the spread of infectious diseases.

2. Vaccination Program: Vaccination programs should be implemented for both animals and humans to help prevent the spread of infection.

By comprehensively addressing these factors, we can work towards protecting global health.

Conclusion

By understanding the factors that contribute to zoonotic diseases and adopting a One Health perspective, we can build a resilient global community that is better equipped to respond to emerging infectious diseases.

FAQs

1. Can dogs pass skin infections to humans?

Yes, dogs can give skin infections to humans. The most common type of skin infection that is transmitted from dogs to humans is ringworm. It is a fungal infection that causes itchy, red, and scaly patches on the skin. Other types of skin infections that spread from dogs to humans include bacterial infections (such as staph infections) and parasitic infections (such as scabies).

2. What diseases can humans get from cows?

There are many diseases that spread from cows to humans. Some of these common diseases are as follows:

• Campylobacteriosis: This is a bacterial infection that causes diarrhea, stomach cramps, fever, and nausea in humans. It is usually spread by contact with contaminated cow feces.

• E. coli O157:H7: This is a type of bacteria that causes symptoms such as severe diarrhea, dehydration, and bloody stools in humans. It spreads through contact with contaminated cow feces.

• Salmonellosis: This is a bacterial infection that can cause diarrhea, fever, and stomach cramps. It is usually spread through contact with contaminated cow feces or meat.

• Brucellosis: This is an infection caused by bacteria that causes fever, fatigue, and muscle pain. It is spread through the consumption of milk, cheese, or other dairy products from infected cows.

• Q fever: This is a bacterial infection that causes symptoms like fever, headache, and muscle pain. It is spread through infected cow's milk, cheese, or other dairy products.

3. What diseases do pigs carry to humans?

Many types of diseases are spread from pigs to humans. Some of the common diseases are trichinosis, tapeworm infection, influenza A, Japanese encephalitis, and Nipah virus.

• Trichinosis: This is a parasitic infection that causes symptoms such as fever, muscle pain, and fatigue. It is spread by eating undercooked pork.

• Tapeworm infection: Tapeworm infection is a parasitic infection due to which symptoms like diarrhea, stomach pain, and weight loss start appearing in the patient. This infection spreads by eating the undercooked meat of a pig.

• Influenza A: This is a virus that causes fever, cough, sore throat, runny nose, and muscle aches. It is spread through contact with infected pigs or their fluids.

• Japanese Encephalitis: Encephalitis is a viral infection that causes symptoms such as fever, headache, and swelling of the brain. It is spread by the bite of an infected mosquito that feeds on an infected pig.

• Nipah Virus: Nipah virus is a virus that causes fever, headache, and swelling in the brain. It spreads through contact with infected pigs.

4. Which animal causes the most disease?

According to the Centers for Disease Control and Prevention (CDC), mosquitoes are the most common carriers of human diseases, spreading diseases such as malaria, dengue fever, and Zika virus. However, when it comes to diseases spread from animals to humans, rodents are the most common source. Rodents spread a variety of diseases, including rabies, hantavirus pulmonary syndrome (HPS), and leptospirosis.

5. Can dogs pass norovirus to humans?

Yes, dogs can spread norovirus to humans. Norovirus is a highly contagious virus that causes vomiting, diarrhea, and stomach cramps in humans. It is usually spread through contact with contaminated feces or vomit. Although dogs are not the primary source of norovirus infection in humans, they still spread the virus to people through their feces or vomit.