Zoonotic infection

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Picture talk

introduction

• Infections spread from man to animals are called zoonotic infections.

• Pathogens shared with wild or domestic animals cause more than 60% of infectious diseases in man(Karesh et al., 2012)

Cont..

• They can either be bacteria viruses fungi or parasites. Zoonotic infection are common because man because he interacts with animals in his daily life .

• The animals include pets that offer companionship ,and animals that are important food sources such as meat, dairy and eggs and the wildlife. This happens because some of this microorganism can infect a varied number of hosts.

• Such pathogens can either be

1. Bacterial

2. Viruses

3. Parasite

4. Fungi

5. Prions

• Man get infected with zoonotic infection through

1. direct contact with an infected animal,

2. indirect contact with the animal

3. through vectors

4. through food that was contaminated with the infected animal.

BACTERIA

1. Anthrax

• spread of the bacillus to man happens due to butchering or eating wildlife or infected domestic carcasses

• bush meat trade

• common in west and central Africa where demand for bush meat is for time greater than in the Amazon basin (Wolfe, Daszak, Kilpatrick, & Burke, 2005)

2. Bovine tuberculosis

• Bovine tuberculosis is a chronic bacterial disease of animals and humans caused by Mycobacterium bovis.

• In a large number of countries bovine tuberculosis is a major infectious disease among cattle, other domesticated animals, and certain wildlife populations.

• Aerosol exposure to M. bovis is considered to be the most frequent route of infection of cattle, but infection by ingestion of contaminated material also occurs to man.(OIE, 2009)

3.E. coli

• Animals are recognized as a reservoir for human intestinal pathogenic E. coli (Bélanger et al., 2011)

• Commensal E. coli strains potentially carrying virulence factors involved in the development of human pathologies also colonize the intestinal tract of animals

• through contact with animals especially poultry and companion animal may contaminates ones hand food or formite

4.Salmonella

• Snakes are considered to be a source of Salmonella infection for humans, but little is known about the actual serotype prevalence in healthy snakes over time(Goupil et al., 2012) but of since snakes are rare encounter birds are

• Birds are the main reservoir of Salmonella enteritidis and human beings are most commonly infected after eating contaminated eggs or egg products from domestic hens(Olsen, Bergstrom, McCafferty, Sellin, & Wistrom, 1996)

5. Borrelia burgdorferi• This pathogen cause lyme disease. Lyme disease is the

most common vector-borne illness in North America and Europe

• Borrelia burgdorferi sensu lato, is transmitted to humans by certain species of Ixodes ticks, which are found widely in temperate regions of the Northern hemisphere.

• Clinical features are diverse, but death is rare. Rates of infection are highest among children 5 to 15years old and adults older than 50 years(Mead, 2015)

• Lyme-like illness lesions, which are similar to the erythema migrans rash of Lyme disease, tend to have lymphocytic dermal infiltrates. With the exception of Borrelia lonestari, the possible causative agent or agents of Lyme-like illness have not been cultured(Masters, Grigery, & Masters, 2008)

6. Rickettsia rickettsii

• It causes Rocky Mountain Spotted Fever (RMSF). Caused by obligate intracellular bacteria grouped in the order Rickettsiales

• Species also include Rickettsia parkeri ,R. japonica in Japan R. conorii caspia in Astrakhan

• R. africae in sub-Saharan Africa and the West Indies R. honei in the Flinders Island,

• Being a vectorbone zoonosis, vector found o transmit the bacteria has been the tick. A new spotted fever R.felis was also found to be associated with fleas(Pérezet al., 2002)

7. Brucella melitensis• Brucellosis, especially caused by Brucella

melitensis, remains one of the most common zoonotic diseases worldwide with more than 500,000 human cases reported annually.

• The bacterial pathogen is classified by the CDC as a category (B) pathogen that has potential for development as a bio-weapon

• Although many countries have eradicated Brucella abortus from cattle, in some areas Brucella melitensis has emerged as a cause of infection in this species as well as in sheep and goats.(Corbel, 1997)

• Unpasteurized milk is the vehicle food

VIRUSES

1.Rabies virus

• Rabies is a disease of carnivores and bats mainly transmissible to humans by bites.

• This virus is neuotropic in nature that causes rabies in man and animal.

• occur through saliva of animals through bite.

• animal movement is very vital for its spread.

• guarantine minimize its importation (Fèvre, Bronsvoort, Hamilton, & Cleaveland, 2006)

2.Arboviruses

• West Nile virus Dengue, and chikungunya,riftvalley fever

• Transmited from mammalian reservoir to man through mosquitoes especially Aedes

• A research done by (LaBeaud et al., 2011) on RVF and WNV found out that the viruses were disseminated within the bodies of the mosquitoes tested.

• Which means the mosquito is also infected to infect sexually trans ovarially,through bite to infected mammal

Avian influenza, crimean-congohemorrhagic fever, ebola and rift

valley fever.• avian influenza,

• Crimean-Congo hemorrhagic fever,

• Ebola

Fungi

• Dermatophytoses are superficial mycoses that may be acquired from infected animals and affect the skin, hair and nails of humans, causing itching, redness, scaling and hair loss.

• Another mycotic infection that can be zoonotic is sporotrichosis.

LARVAL CESTOTDES

1.Echinococcosis• hydatid disease attributable to the larval stage of

Echinococcus spp. E. granulosus, E. multilocularisthe cause of alveolar echinococcosis

• Humans are infected by ingesting eggs shed in the feces of canine definitive hosts.

• The result is the formation of slow-growing larval cysts in the liver, lungs, or other organ systems, which eventually produce clinical signs from mass effects, allergic reactions, or through tissue necrosis/fibrosis.

2.cysticercosis

• caused by larval Taenia solium. adult worms residing in the intestinal tract.

• Swine become infected upon ingestion of eggs shed in the feces of an infected human tapeworm carrier resulting in larval cyst formation (cysticercosis) in muscle and other tissues. The cycle continues when humans acquire the tapeworm form by ingesting undercooked infected pork.

• When cyst formation occurs in the brain, the resulting condition is termed neurocysticercosis (NCC), a major cause of seizures and epilepsy in T. solium–endemic regions(Budke, White, & Garcia, 2009)

4. trypanosomiasis (

• Causes sleeping sickness

• transmitted by tsetsefly female and male from warm blooded animals to man

PRIONS

• The agent of Bovine Spongiform Encephalopathy is thought to be the cause of variant Creutzfeldt-Jakob Disease (vCJD) which is a degenerative neurological disease different from CJD, at present inevitably lethal in humans.

Reference

Bélanger, L., Garenaux, A., Harel, J., Boulianne, M., Nadeau, E., & Dozois, C. M. (2011). Escherichia colifrom animal reservoirs as a potential source of human extraintestinal pathogenic E. coli. FEMS Immunology and Medical Microbiology. https://doi.org/10.1111/j.1574-695X.2011.00797.x

Budke, C. M., White, A. C., & Garcia, H. H. (2009). Zoonotic larval cestode infections: Neglected, neglected tropical diseases? PLoS Neglected Tropical Diseases, 3(2), 2–4. https://doi.org/10.1371/journal.pntd.0000319

Corbel, M. J. (1997). Brucellosis: An Overview. Emerging Infectious Diseases, 3(2), 213–221. https://doi.org/10.3201/eid0302.970219

Fèvre, E. M., Bronsvoort, B. M. D. C., Hamilton, K. A., & Cleaveland, S. (2006). Animal movements and the spread of infectious diseases. Trends in Microbiology, 14(3), 125–131. https://doi.org/10.1016/j.tim.2006.01.004

Goupil, B. a, Trent, A. M., Bender, J., Olsen, K. E., Morningstar, B. R., & Wünschmann, A. (2012). A longitudinal study of Salmonella from snakes used in a public outreach program. Journal of Zoo and Wildlife Medicine, 43(4), 836–841. https://doi.org/10.1638/2011-0281R1.1

Karesh, W. B., Dobson, A., Lloyd-Smith, J. O., Lubroth, J., Dixon, M. A., Bennett, M., … Heymann, D. L. (2012). Ecology of zoonoses: Natural and unnatural histories. The Lancet, 380(9857), 1936–1945. https://doi.org/10.1016/S0140-6736(12)61678-X

Cont..

LaBeaud, A. D., Sutherland, L. J., Muiruri, S., Muchiri, E. M., Gray, L. R., Zimmerman, P. A., … King, C. H. (2011). Arbovirus prevalence in mosquitoes, Kenya. Emerging Infectious Diseases, 17(2), 233–241. https://doi.org/10.3201/eid1702.091666

Masters, E. J., Grigery, C. N., & Masters, R. W. (2008). STARI, or Masters Disease: Lone Star Tick-Vectored Lyme-like Illness. Infectious Disease Clinics of North America. https://doi.org/10.1016/j.idc.2007.12.010

Mead, P. S. (2015). Epidemiology of Lyme Disease. Infectious Disease Clinics of North America. https://doi.org/10.1016/j.idc.2015.02.010

OIE. (2009). Bovine Tuberculosis. OIE Terrestrial Manual 2009, (May), 1–16. https://doi.org/10.1371/journal.pone.0024629

Olsen, B., Bergstrom, S., McCafferty, D., Sellin, M., & Wistrom, J. (1996). Salmonella enteritidis in Antarctica: zoonosis in man or humanosis in penguins? Lancet, 348(9037), 1319–1320. https://doi.org/10.1016/S0140-6736(05)65807-2

Pérez, M. P., Palacio, J., Santolaria, M. P., Aceña, M. D. C., Chacón, G., Verde, M. T., … García-Belenguer, S. (2002). Influence of lairage time on some welfare and meat quality parameters in pigs. Veterinary Research, 33(3), 239–250. https://doi.org/10.1051/vetres

Wolfe, N. D., Daszak, P., Kilpatrick, A. M., & Burke, D. S. (2005). Bushmeat hunting, deforestation, and prediction of zoonotic disease emergence. Emerging Infectious Diseases, 11(12), 1822–1827. https://doi.org/10.3201/eid1112.040789