Diseases of Camelus dromedarius of zoonotic importance
Akshika Agrawal1*, Shipra1
- M.V. Sc scholar, Department of Veterinary Public Health and Epidemiology, RAJUVAS, Bikaner
*Corresponding author: akshikaagrawal03@gmail.com
The camel (genus Camelus), is a large ruminating hoofed animal that lives in Africa and Asia and is known for its ability to move for long periods without drinking water. There are two species of domestic camel and one species of wild camel. Both species have been domesticated. Camels are divided into one-humped and two-humped camels, commonly known as dromedary and bactrians; whereas wild spp. of camels are called Camelus ferus. Wild Bactrian camels are found in parts of China and Mongolia, and domesticated camels have been introduced to arid and semiarid regions worldwide. Most of the camels in the world are dromedary camels, with the smaller Bactrian camel found in Central Asia. There are approximately 15 million dromedary camels worldwide, with the largest populations found in Somalia and Sudan, while there are under 1 million dromedary camels in India, mostly in the state of Rajasthan. India has one of the largest camel populations, with an estimated 3 million individuals, found mostly in the western states of Rajasthan, Gujarat, and Haryana. In 1758, Linnaeus first classified the dromedary as Camelus dromedarius. It is found in tropical Africa, the Middle East and the Indian subcontinent, and is important for nomadic and pastoral communities in these regions as a source of good animal protein in the form of milk and meat. It is characterized by a long, arched neck, a deep, narrow chest and a hump. The hump is composed of fat held together by connective tissue and serves as a food storage facility when needed. Male dromedaries are about 10% heavier than females, weighing 400–600 kg, standing about 10 cm high at the withers and standing 1.8–2.0 m long.
Camels are a vital source of income and livelihood for many communities around the world. They provide milk, meat, hides and hair, transport, fertilizers, labour, live capital etc. Camel milk is unique in terms of having low fat (1.5-3%), low protein (2.5%) has longer shelf life, higher ratio of ß-casein to k-casein, absence of lysozyme C and ß-lactoglobulin and presence of whey acidic protein and peptidoglycan recognition protein.
With the high temperature in the areas and the conditions camels are reared in, it is highly likely for camels to be affected with multiple diseases. Some of the common zoonotic diseases in camels are mentioned in Table1,2 and 3.
Table 1: Summary of Bacterial zoonotic diseases of camelus dromedarius spp.:
| Disease | Causative agent | Transmission | Country, outbreak |
| Brucellosis | Brucella abortus
Brucella melitensis |
Commercialised camel milk | 2016, Israel |
| Tuberculosis | Mycobacterium bovis (antelope clade)
Mycobacterium clade |
Contact with excretion of desert gazelles;
Inhalation |
2005, United Arab Emirates
2004, Slovenia (zoo) |
| Anthrax | Bacillus anthracis | Ingestion of contaminated milk and meat | Feb 1988, Sudan (Kulbus town and Chad border) |
| Plague | Yersinia pestis | Contact and consumption of contaminated camel meat | 1976, Libyan village |
| Pasteurellosis | Mannheimia haemolytica
Pasteurella multocida |
Inhalation;
Ingestion; Direct contact; Exposure to ticks (Rainy season) |
1936,1943 and 1969, Iran
2009, Larestan, south of Iran Feb 2010, Pali, Rajasthan |
| Listeriosis
(food-borne disease) |
Listeria monocytogenes | Consumption of contaminated milk and meat products;
Vaginal secretion |
1961 South American camelids in Peru |
Table 2: Summary of Viral zoonotic diseases of camelus dromedarius spp.:
| Disease | Causative agent | Transmission | Country, outbreak |
| Rabies | Lyssavirus (Rhabdoviridae family) | Saliva of a rabid animal’s bite;
Scratches or contaminated mucous |
2008, Torod region of Semnan province (Central Iran)
2012, Khoda Afarin county in East Azerbaijan province |
| Camel pox
(Contagious skin disease) |
Camelpox virus
(Poxviridae family) |
Direct contact between infected and susceptible animals | 1996, Kazakhstan
2022, Bikaner Rajasthan
|
| MERS-Cov | Coronavirus | Contractable through direct or indirect contact with infected animals | 2012, Saudi Arabia
October 2014, Zabol city, Siastan and Baluchistan province (Southeastern Iran) |
| Rift valley fever | Rift valley fever virus
(Phenuiviridae family) |
Mosquitoes borne | 2020 and 2022, Mauritania |
| Hepatitis E | Orthohepevirus
(Hepeviridae family) |
Contact with infected animal and its products;
faecal-oral route |
2016, United Arab Emirates |
| Crimean-Congo haemorrhagic fever | Arbovirus
(Nairoviridae family) |
Tick borne, direct contact with fresh meat or blood of viraemic animals | 2019, Algeria
2024, Nigeria |
Table 3: Summary of Parasitic zoonotic diseases of camelus dromedarius spp.:
| Disease | Causative agent | Transmission | Country, outbreak |
| Trypanosomiasis | Trypanosoma evansi | Bite of infected biting insects | 2016, Canary island
Ethiopia |
| Cystic echinococcosis | Echinococcus granulosis (tapeworm of larvae)
Echinococcus canadensis |
Ingesting the parasite eggs in contaminated food and water
|
Iran and Ethiopia
1964,1980,1990 Egypt
Nigeria and Oman |
| Toxoplasmosis | Toxoplasma gondii | Ingesting sporulated oocysts shed in the faces of cats and other wild animals | 2018, Algeria
2012-2013, Ethiopia 2013, Iran 2020, Egypt
|
