Zoonotic Diseases - Learn About Its Causes, Transmission, Symptoms, and Prevention for UPSC!
Humans, livestock, and the environment together play an important role in the origin and transmission of numerous Zoonotic diseases. The majority of these contagious diseases that impact humans have animal origins. A zoonotic pathogen (a microorganism that causes illness) might be a bacteria, virus, parasite, or contain a novel agent. It can cause infection through direct contact, contaminated Soil, food, water, habitat, etc. Even a healthy person can become ill through simple touch with them. In India and around the world, zoonotic illnesses are quite prevalent.
In this article, we will discuss Zoonotic Disease, its Meaning, Types, Causes, Symptoms, Transmission, Prevention & More UPSC IAS Exam. As this topic is an important part of the Science & Technology (Biology – Human Health and Disease) section of mains GS Paper 3.
What is a Zoonotic Disease?
Zoonotic disease or zoonosis is any group of diseases or infections that can be naturally transmissible from vertebrate animals to people, including mammals, amphibians, reptiles, birds, and fishes. Also, large numbers of domestic and wild animals are sources of zoonotic disease, and there are numerous means of transmission. Currently, there are more than 200 known types of zoonoses that are responsible for zoonotic diseases.
History of Zoonotic diseases
The history of the most significant Zoonotic diseases and their outbreak is provided in brief in the following table:
| Year | An Overview |
| 224 BC | First outbreak of plague was reported. |
| 541-46 CE | The 1st plague pandemic outbreak was reported in Europe and Asia. |
| 1346-1352 | The 2nd plague pandemic known as the black death was reported in Europe. |
| 1648 CE | The first outbreaks of Yellow Fever disease occurred in Barbados. |
| 1997 | Avian influenza A (Bird Flu or H5N1)- 1st case of human infection was identified in Hongkong. |
| 2019 | SARS Cov-2 1st case identified in China. |
Examples of zoonotic diseases
The details of the top 10 zoonotic diseases are as follows:
| Top 10 Zoonotic Diseases | An Overview |
| Yellow fever (YF) |
|
| Kyasanur forest disease (KFD) |
|
| West Nile Virus(WNV) |
|
| Severe acute respiratory syndrome (SARS-CoV) & the Middle East respiratory syndrome coronavirus (MERS-CoV) | SARS-CoV and MERS-CoV are transmitted from civet cats and dromedary camels to humans respectively. |
| The pandemic of Coronavirus disease (COVID-19) |
|
| Nipah virus infection |
|
| Malaria, Dengue and Chikungunya |
|
| Plague |
|
Learn about National Rural Health Mission also!
Monkey Pox – A Zoonotic Disease
Monkeypox is a viral zoonotic illness, which means it may transfer from animals to humans. It is caused by the monkeypox virus (MPXV), a member of the Orthopoxvirus genus in the Poxviridae family.
| Monkeypox virus (MPXV) is a double-stranded DNA virus that is the etiological agent of the zoonotic disease monkeypox (MPX). It is divided into two genetic clades:
The symptoms of MPX: range from fever to respiratory distress and are identical to those of smallpox with the exception of lymphadenopathy. Incubation period: 5 to 21 days. |
UPSC Beginners Program
Get UPSC Beginners Program - 60 Days Foundation Course SuperCoaching @ just
People also like
Classification Of Zoonotic Diseases
There are three major categories into which zoonotic diseases can be classified namely according to the etiological agents, according to the mode of transmission, and according to the reservoir host. These are discussed in detail below:
According to the Etiological Agents
All classes of disease agents (etiological agent or zoonoses) cause zoonotic disease, including bacteria, viruses, parasites and fungi that are as follows:
| Classification | Meaning | Example of Disease |
| Bacterial Zoonoses | A zoonosis caused by bacteria | Leprosy, Bubonic plague, Anthrax, Lyme disease, etc. |
| Viral Zoonoses | A zoonosis caused by the virus | Avian influenza, Ebola virus disease (Ebola Hemorrhagic fever), Severe acute respiratory syndrome (SARS), Zika, Monkey-Pox, etc. |
| Parasitic Zoonoses | A zoonosis caused by Parasite | Trichinellosis, Cryptococcosis, etc. |
| Mycotic (fungal) Zoonoses | A zoonosis caused by Fungi | Histoplasmosis, and sporotrichosis. |
| Rickettsial Zoonoses | A zoonosis caused by Rickettsia species – Gram-negative bacilli that live in eukaryotic cells as obligate intracellular parasites.
It is spread through the bites of infected ticks or mites, as well as through the excrement of infected lice or fleas. |
Epidemic typhus, Q-Fever, Murine typhus, etc. |
| Chlamydial Zoonoses | A zoonosis caused by Chlamydia psittaci | Chlamydiosis |
| Protozoan Zoonoses | A zoonosis caused by Protozoa | Leishmaniasis |
| Note: A vector is an organism that transmits an infection while non-lethally feeding on the internal fluids of another host. |
According to the Mode of Transmission
Zoonotic diseases are classified as follows according to the mode of transmission:
| Transmission mode | An overview | Image |
| Direct zoonoses (Orthozoonoses) |
|
Epidemiological maintenance cycle of rabies, a direct zoonosis (ortho zoonosis)
|
| Cyclozoonosis |
|
Epidemiological maintenance cycle of taeniasis and cysticercosis (Taenia solium), a cyclozoonosis.
|
| Phero Zoonoses- (also called Metazoonoses) |
|
Epidemiological maintenance cycle of plague, a metazoonosis.
|
| Saprozoonosis |
|
Epidemiological maintenance cycle of Erysipelothrix infection, a saprozoonosis.
|
Read more about Leucism
According to the reservoir host
The term “reservoir host” refers to the animal or organism where the pathogen typically resides, may develop, and perhaps multiplies. Classification of zoonotic disease as per the reservoir host is discussed in the table below:
| Type of infection | Reservoir Host |
| Anthropozoonosis Infections |
|
| Zooanthroponosis Infections |
|
| Amphixenosis Infections |
|
Learn about National Urban Health Mission also!
Latest Update on Zoonotic Diseases
- In July 2022- The World Health Organization (WHO) designated the monkeypox virus outbreak as an emergency, something that is reserved for diseases of the highest concern.
- According to the World’s Forests 2022 report and a research paper that was published in the journal “Nature,” stated – “Climate change could result in more than 15,000 more cases of viral transmission to animals over the course of the next 50 years”.
Status of Zoonotic Diseases in India
- In India, the top major diseases are rabies, brucellosis, toxoplasmosis, plague, cysticercosis, Nipah, echinococcosis, Japanese Encephalitis (JE), leptospirosis, Scrub typhus, trypanosomiasis, Crimean-Congo, hemorrhagic fever and Kyasanur forest disease (KFD).
- The Central Bureau of Health Intelligence (CBHI) provisionally reported around 101,192 cases of dengue, 57813 cases of chikungunya, 14971 cases of H1N1, 4380 cases of kala-azar, 1674 cases of Japanese encephalitis, and 110 cases of rabies were reported in 2018.
How are Zoonotic Diseases Transmitted?
Zoonotic pathogens can be spread to humans through any contact point with domestic, agricultural, and wild animals, etc. Some of the ways of transmission are
- Direct contact – People may become ill through direct contact with an infected animal’s mucus, saliva, blood, urine, damaged skin, and other body fluids.
- Indirect contact – Wild and domestic animals, such as cattle, dogs, cats, bats, pigs, raccoons, and rodents, carry the pathogen and pass them on via their urine, saliva, sweat, etc to nearby objects and surfaces and contaminate them.
- Vector-borne – Being bitten by a tick, mosquito, or flea.
- Waterborne – Drinking or contact with water-containing pathogens can infect both humans and animals.
Learn about some Health Issues Here!
Causes of Zoonotic Disease
Zoonotic diseases are caused by:
- Viruses,
- Bacteria,
- Parasites,
- Fungi, etc.
These above microorganisms have the potential to infect humans and animals with a wide range of ailments, resulting in mild to fatal conditions.
Learn about Malnutrition in India Here!
Symptoms of Zoonotic Disease
There are some typical signs and symptoms of zoonotic diseases which are described below:
| Signs and Symptoms | Illness |
| Gastrointestinal (GI) symptoms | Pain, Diarrhea (can be severe), Abdominal cramps, Poor appetite, Vomiting, Nausea, etc. |
| Flu-like symptoms | Fever, Headache, Fatigue, Body aches, and Swollen lymph nodes. |
| Skin symptoms | Skin lesions, bite marks, scratches, rash, etc. |
| Respiratory symptoms | sore throat, nasal congestion, or cough. |
Prevention of Zoonotic Disease
Zoonotic diseases are common, however, we can try the following steps to prevent them:
-
- Washing your hands: Wash hands immediately after contact with domestic and wild animals.
- Non-Veg prevention: Avoid eating raw and undercooked meats.
- Mosquito prevention: To avoid mosquito bites, use proper mosquito spray or gel, as well as pay attention to the cleanliness of the surroundings.
- Food safety: Follow food safety measures like washing and cooking, and handling food properly.
- Avoid infected zones: Do the necessary research before traveling and avoid traveling to areas where high zoonotic disease infections have spread.
- Prevention related to medical waste management: Medical waste should be disposed of using modern techniques,
- Consultation: If you have been hurt by an animal (e.g. bits and scratches), consult and get treatment from your nearest primary hospital.
Read about Japanese Encephalitis here!
Zoonotic Diseases – A Public Health Problem
Globally, there are estimated to be more than one billion cases of the disease and millions of deaths each year from zoonotic diseases alone. About 60 percent of emerging infectious diseases reported globally each year are zoonoses.
- In India, Zoonotic diseases are a major public health problem. The plague alone has killed about 1.2 million people since 1898. Zoonotic diseases like Rabies, Chikungunya, Dengue, Malaria, etc., remain a serious health problem in the country.
- According to a recent analysis, China and India may soon emerge as the two countries with the most potential for the spread of new zoonotic viral illnesses.
- Zoonotic diseases pose severe risks to the security of the global health system.
- Multisectoral and interdisciplinary collaborations are currently required to successfully mitigate and avoid the consequences of endemic and emerging zoonotic diseases of public health concern.
- However, WHO continues to work with national governments, academia, non-governmental and philanthropic organizations, and regional and international partners to prevent and manage zoonotic threats and their public health, social and economic impacts.
Programs Run by India to Prevent Zoonotic Diseases
- National Rabies Control Programme.
- Programme for prevention and control of leptospirosis.
- National One Health Programme for Prevention & Control of Zoonoses.
- Inter-Sectoral coordination for Prevention and Control of Zoonotic Diseases
Conclusion
Zoonotic diseases have caused periodic outbreaks in humans globally. Most emerging infections in humans are zoonotic. The current COVID-19 is a perfect example of an identified emerging zoonotic disease that continues to cause a global pandemic. Anthropogenic factors such as modernization of animal husbandry and agriculture, destruction of wild animal habitats, mixing of wild and domestic animals, wildlife hunting, wildlife trade, changing food habits and urbanization can increase the emergence of zoonotic diseases in humans.
Check out the test series for UPSC IAS Exam here.
We hope all your doubts regarding “Zoonotic Diseases” are addressed after going through this article. Testbook provides comprehensive notes for different competitive examinations. It has always assured the quality of its product like content pages, live tests, GK and current affairs, mocks, and so on. Ace your preparation with the Testbook App!
जूनोटिक रोग – यूपीएससी के लिए इसके कारण, संचरण, लक्षण और रोकथाम के बारे में यहाँ जानें!
