Zoonotic Diseases

Many of the world’s newly recognized diseases are zoonoses.  A zoonosis or zoonotic disease is one that normally exists in animals, but can infect humans.  Human illness from a zoonotic disease agent is often accidental.  People can become infected through contact with infected livestock, game animals, and pets.  Also, some zoonotic diseases are transmitted to humans through tick and mosquito bites.

Newly recognized zoonotic diseases are also called “emerging” zoonoses.  Reports of some zoonoses have increased because the viral or bacterial disease agent was accidentally spread from one part of the world to another.  Increases also may result when animal or insect carriers of a disease move from one part of the world to another.  Also, some people’s lifestyles and occupations bring them into close contact with animal or insect carriers of these diseases.

Public awareness of zoonoses has increased because they can have serious human health and economic impacts.  One example is the hantavirus pulmonary syndrome, an uncommon but sometimes fatal disease that is linked to close contact between people and wild rodents.  Another zoonotic disease, Severe Acute Respiratory Syndrome (SARS) was linked to people’s exposure to exotic animals at open meat markets in China.  SARS caused economic and social chaos in China in 2003 when people stopped going to work to avoid infection.  And because there is a chance the H5N1 avian influenza virus may change into a form that is more transmissible to people, southeast Asian and Middle East poultry farms have been forced to cull infected flocks.  This, of course, has resulted in serious economic impacts to the growers and related industries.

New zoonotic diseases will likely continue to surface for a number of reasons.  The global trade of animal products, wildlife, and exotic pets can introduce disease agents into new places.  Increasing urbanization brought on by population growth brings wildlife species together on small remnants of natural habitat, making it more likely the animals will share diseases.  Other environmental changes brought about by human activity may actually create more habitats for animal or insect carriers of disease.

Information sharing is a key factor needed to prevent and control zoonotic diseases.  For example, valuable partnerships were created between local, state, and federal agencies and public and private universities before West Nile virus (WNV) was found in Missouri.  These partnerships allowed the state to track the activity of the virus and its mosquito carriers, so that prevention messages and control measures could be set in motion.  These partnerships have been strengthened and expanded as the public and private sector cooperate on forming strategies to respond to pandemic influenza.

For more information on zoonotic and other emerging infectious diseases, go to the CDC Emerging Infectious Disease Journal.  This peer-reviewed journal was established to promote the recognition of new and reemerging infectious diseases around the world and improve the understanding of factors involved in disease emergence, prevention, and control.

Click here to go to the Zoonotic Disease Section of the Communicable Disease Surveillance 2005 Annual Report. 

Reportable Zoonotic Diseases in Missouri:

Brucellosis
CDC Health Topics:
http://www.cdc.gov/ncidod/diseases/submenus/sub_brucellosis.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Brucellosis.pdf

Ehrlichiosis
CDC Health Topics:
http://www.cdc.gov/ncidod/dvrd/ehrlichia/Index.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Ehrlichiosis.pdf

Lyme Disease
CDC Health Topics:
http://www.cdc.gov/ncidod/dvbid/lyme/index.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Lyme.pdf

Malaria
CDC Health Topics:
http://www.cdc.gov/malaria/
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Malaria.pdf

Q Fever
CDC Health Topics:
http://www.cdc.gov/ncidod/dvrd/qfever/index.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/QFever.pdf

Rocky Mountain Spotted Fever
CDC Health Topics:
http://www.cdc.gov/ncidod/dvrd/rmsf/index.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/RMSF.pdf

Tularemia
CDC Health Topics:
http://www.cdc.gov/ncidod/diseases/submenus/sub_tularemia.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Tularemia.pdf

West Nile Virus Disease
CDC Health Topics:
http://www.cdc.gov/ncidod/dvbid/westnile/index.htm
Missouri Communicable Disease Investigation Reference Manual:
http://www.dhss.mo.gov/CDManual/Encephalitis.pdf & http://www.dhss.mo.gov/CDManual/WNVFever.pdf

Zoonoses
CDC Health Topics:
http://www.cdc.gov/ncidod/diseases/list_zoonotic.htm
World Health Organization Health Topic:
http://www.who.int/zoonoses/vph/en/

Mosquito-borne Diseases
CDC Health Topics:
http://www.cdc.gov/ncidod/diseases/list_mosquitoborne.htm

Tick-borne Diseases
CDC Health Topics:
http://www.cdc.gov/ncidod/diseases/list_tickborne.htm