Rabies epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Syed Hassan A. Kazmi BSc, MD [2]

Overview[edit | edit source]

According to the World Health Organization (WHO), human rabies is present in 150 countries and territories and on all continents, except for Antarctica. India has been known to have the highest incidence of rabies. Twenty-three cases of human rabies have been reported in the United States in the past decade (2008-2017). Many territories, such as the United Kingdom, Ireland, Taiwan, Japan, Hawaii, Mauritius, Barbados and Guam, are free of rabies. Worldwide, 55,000 human deaths occur annually from rabies, with 56 % of deaths estimated to occur in Asia and 44 % in Africa.

Epidemiology and Demographics[edit | edit source]

Prevalence[edit | edit source]

Worldwide

• According to the World Health Organization (WHO), human rabies is present in 150 countries and territories and on all continents, except for Antarctica
• Canine rabies is known to be endemic in parts of Africa, Asia, and Central and South America. Dogs account for over 99 % of all rabies transmission to humans^[1][2]
• The following map represents the global estimate of dog-transmitted rabies, based on WHO estimates:

United States

According to CDC, rabies is rare in the United States:^[3]

• Human rabies cases in the United States are rare, with only 1 to 3 cases reported annually
• Twenty-three cases of human rabies have been reported in the United States in the past decade (2008-2017). Eight of these were contracted outside of the U.S. and its territories
• In 2001, 49 states, the District of Columbia, and Puerto Rico reported 7,437 cases of rabies in animals and no cases in humans, according to CDC (Hawaii is the only state that has never reported an indigenously acquired rabies case in humans or animals). The total number of reported cases increased by 0.92% from those reported in 2000 (7,369 cases).

Incidence[edit | edit source]

Worldwide

• A rabies epidemic occurs every 10 years in China^[4]
• India is reported to have the highest incidence of rabies^[5]
• In Ethopia, the estimated annual incidence in humans is 2.33 cases per 100,000 individuals^[6] 
• The following table outlines the incidence of rabies in developing countries, according to WHO:^[7]

United States

The following table outlines the cases of rabies in humans in the United States and Puerto Rico from January 2008 through September 2017 by mode of exposure and rabies virus (RV) variant responsible for infection:^[8]

Legend: Dr = Desmodus rotundus. Ln = Lasionycteris noctivagans. My sp = Myotis species. Ps = Perimyotis subflavus.Tb = Tadarida brasiliensis

Developed countries[edit | edit source]

• Many territories, such as the United Kingdom, Ireland, Taiwan, Japan, Hawaii, Mauritius, Barbados and Guam, are free of rabies, although there may be a very low prevalence of rabies among bats in the UK
• New Zealand and Australia have never had rabies.[3] However, in Australia, the Australian Bat Lyssavirus occurs normally in both insectivorous and fruit eating bats (flying foxes) from most mainland states. Scientists believe it is present in bat populations throughout the range of flying foxes in Australia

Countries and political units reporting no indigenous cases of rabies during 2005:

Age[edit | edit source]

• Worldwide, children under 15 years of age have a higher rabies exposure risk, and most exposures are from dog bites^[9]

Case-mortality rate[edit | edit source]

• Worldwide, 55,000 human deaths occur annually from rabies, with 56 % of deaths estimated to occur in Asia and 44 % in Africa^[10]
• An estimated 31,000 human deaths due to rabies occur annually in Asia, with the majority (around 20,000 occuring in India)^[11][12][13]
• More than 99% of all human deaths from rabies occur in Africa, Asia, South America and India which report thirty thousand deaths annually.^[14] One of the sources of recent flourishing of rabies in the East Asia is the pet boom. China introduced the "One-dog policy" in November 2006 to control the problem.^[15]
• The number of human rabies deaths in the United States attributed to rabies has been steadily declining since the 1970’s thanks to animal control and vaccination programs, successful outreach programs, and the availability of modern rabies biologics

Non-human rabies[edit | edit source]

Wild Animals[edit | edit source]

Wild animals accounted for 93% of reported cases of rabies in 2001. Raccoons continued to be the most frequently reported rabid wildlife species (37.2% of all animal cases during 2001), followed by skunks (30.7%), bats (17.2%), foxes (5.9%), and other wild animals, including rodents and lagomorphs (0.7%). Reported cases in raccoons and foxes decreased 0.4% and 3.5% respectively from the totals reported in 2000. Reported cases in skunks, and bats increased 2.6%, and 3.3% respectively from the totals reported in 2000.

Outbreaks of rabies infections in terrestrial mammals like raccoons, skunks, foxes, and coyotes are found in broad geographic regions across the United States. Geographic boundaries of currently recognized reservoirs for rabies in terrestrial mammals are shown on the map below.

Domestic Animals[edit | edit source]

Domestic species accounted for 6.8% of all rabid animals reported in the United States in 2001. The number of reported rabid domestic animals decreased 2.4% from the 509 cases reported in 2000 to 497 in 2001.

In 2001, cases of rabies in cats increased 8.4%, whereas those in dogs, cattle, horses, sheep and goats, and swine decreased 21.9%, 1.2%, 1.9% and 70.0% respectively compared with those reported in 2000. Rabies cases in cats continue to be more than twice as numerous as those in dogs or cattle. Pennsylvania reported the largest number of rabid domestic animals for any state, followed by New York.

References[edit | edit source]

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