Prevalence of rabies

Almost all human deaths caused by rabies occur in Asia and Africa. There are an estimated 55,000 human deaths annually from rabies worldwide.^[1]

Dog licensing, euthanasia of stray dogs, muzzling, and other measures contributed to the elimination of rabies from the United Kingdom in the early 20th century. More recently, large-scale vaccination of cats, dogs and ferrets has been successful in combating rabies in many developed countries.

Rabies is a zoonotic disease, caused by the rabies virus. The rabies virus, a member of the Lyssavirus genus of the Rhabdoviridae family, survives in a diverse variety of animal species, including bats, monkeys, raccoons, foxes, skunks, wolves, coyotes, dogs, mongoose, weasels, cats, cattle, domestic farm animals, groundhogs, bears, and wild carnivores. However, dogs are the principal host in Asia, parts of America, and large parts of Africa. Mandatory vaccination of animals is less effective in rural areas, especially in developing countries where pets may be community property and their destruction unacceptable. Oral vaccines can be safely administered to wild animals through bait, a method initiated on a large scale in Belgium that has successfully reduced rabies in rural areas of Canada, France, the United States, and elsewhere. For example, in Montreal baits are successfully ingested by raccoons in the Mount Royal park area.

Asia

An estimated 31,000 human deaths due to rabies occur annually in Asia,^[1] with the majority – approximately 20,000 – concentrated in India.^[2] Worldwide, India has the highest rate of human rabies in the world primarily due to stray dogs. Because of a decline in the number of vultures due to acute poisoning by the anti-inflammatory drug diclofenac, animal carcasses that would have been consumed by vultures instead became available for consumption by feral dogs, resulting in a growth of the dog population and thus a larger pool of carriers for the rabies virus.^[3] Another reason for the great increase in the number of stray dogs is the 2001 law that forbade the killing of dogs.^[2]

In many Asian countries which still have a high prevalence of rabies, such as Vietnam and Thailand, the virus is primarily transmitted through canines (feral dogs and other wild canine species).^[4] Another source of rabies in Asia is the pet boom. In 2006 China introduced the "one-dog policy" in Beijing to control the problem.^[5]

The island of Bali in Indonesia has been undergoing a severe outbreak of canine rabies since 2008, that has also killed about 78 humans as of late September 2010.^[6] Unlike predominantly Muslim parts of Indonesia, in Bali many dogs are kept as pets and strays are tolerated in residential areas.^[7] Efforts are under way to vaccinate pets and strays, as well as selective culling of some strays,^[6] to control the outbreak. As Bali is a popular tourist destination, visitors are advised to consider rabies vaccinations before going there, if they will be touching animals.^[8]

Israel

Since 1948, 29 people have been reported dead from rabies in Israel. The last death was in 2003, when a 58-year-old Bedouin woman was bitten by a cat and became infected. She was not inoculated and later died.^[9]

Japan

Rabies existed in Japan with a particular spike in the mid 1920s, but a dog vaccination campaign and increased stray dog control reduced cases.^[10] The Rabies Control Act was enacted in 1950, and^[11] the last human and animal cases were reported in 1954 and 1957,^[12] and Japan is believed to have been rabies-free since 1957.^[13]

There have been three imported cases since then, a college student who died in 1970, and two elderly men who had travelled to the Philippines and been bitten there by rabid dogs, and then died after returning to Japan.^[10][14][15]

Africa

Approximately 24,000 people die annually in Africa^[16] a rate of approximately 23 per million population.

South Africa

In South Africa between 10 and 30 cases of human rabies are confirmed every year and it is particularly widespread in the north-eastern regions of the Eastern Cape, the eastern and south-eastern areas of Mpumalanga, northern Limpopo and KwaZulu-Natal.^[17] Dogs are the main vector (especially in the east of the country)for the disease but also wildlife, including the bat-eared fox, yellow mongoose and black-backed jackal.^[18] The death rate of 13 per annum over the decade 2001-2010 ^[19] is a rate of approximately 0.26 per million population. This is approximately 30 times the rate in the United States but 1/90th of the African average. The number of cases per province over the last decade are as follows:

North America

USA

Human deaths from rabies have decreased dramatically from over 100 per year in the early 20th century to one or two annually in the 1990s.^[20] Many of the recent deaths that have occurred were due to exposure outside the United States.^[21] In 2013 three human rabies cases were reported.^[22]

Southern United States

Rabies was once rare in the United States outside the Southern states, but raccoons in the mid-Atlantic and northeast United States have been suffering from a rabies epidemic since the 1970s, that is now moving westwards into Ohio.^[23]

Cases of animal rabies in the United States in 2001

The particular variant of the virus has been identified in the southeastern United States raccoon population since the 1950s, and is believed to have traveled to the northeast as the result of infected raccoons being among those caught and transported from the southeast to the northeast by human hunters attempting to replenish the declining northeast raccoon population.^[24] As a result, urban residents of these areas have become more wary of the large but normally unseen urban raccoon population. It has become the common assumption that any raccoon seen diurnally is infected; certainly the reported behavior of most such animals appears to show some sort of illness, and necropsies can confirm rabies. Whether as a result of increased vigilance or only the common human avoidance reaction to any other animal not normally seen, such as a raccoon, there has only been one documented human rabies case as a result of this variant.^[25][26] This does not include, however, the greatly increasing rate of prophylactic rabies treatments in cases of possible exposure, which numbered fewer than one hundred humans annually in the state of New York before 1990, for instance, but rose to approximately ten thousand annually between 1990 and 1995. At approximately $1,500 per course of treatment, this represents a considerable public health expenditure. Raccoons do constitute approximately 50% of the approximately eight thousand documented non-human rabies cases in the United States.^[27] Domestic animals constitute only 8% of rabies cases, but are increasing at a rapid rate.^[27]

Midwestern United States

A rabid dog, with saliva dripping out of the mouth

In the midwestern United States, skunks are the primary carriers of rabies, composing 134 of the 237 documented non-human cases in 1996. The most widely distributed reservoir of rabies in the United States, however, and the source of most human cases in the U.S., are bats. Nineteen of the twenty-two human rabies cases documented in the United States between 1980 and 1997 have been identified genetically as bat rabies. In many cases, victims are not even aware of having been bitten by a bat, assuming that a small puncture wound found after the fact was the bite of an insect or spider; in some cases, no wound at all can be found, leading to the hypothesis that in some cases the virus can be contracted via inhaling airborne aerosols from the vicinity of bats. For instance, the Centers for Disease Control and Prevention (CDC) warned on May 9, 1997, that a woman who died in October 1996 in Cumberland County, Kentucky and a man who died in December 1996 in Missoula County, Montana were both infected with a rabies strain found in silver-haired bats; although bats were found living in the chimney of the woman's home and near the man's workplace, neither victim could remember having had any contact with them.^[28] Similar reports among spelunkers led to experimental demonstration in animals.^[29] This inability to recognize a potential infection, in contrast to a bite from a dog or raccoon, leads to a lack of proper prophylactic treatment, and is the cause of the high mortality rate for bat bites.

On September 7, 2007, rabies expert Dr. Charles Rupprecht of Atlanta-based U.S. Centers for Disease Control and Prevention said that canine rabies had disappeared from the United States. Rupprecht emphasized that the disappearance of the canine-specific strain of rabies virus in the US does not eliminate the need for dog rabies vaccination as dogs can still become infected from exposure to wildlife.^[30]

Europe

Several countries in Europe have been designated rabies-free jurisdictions: Austria, United Kingdom, Ireland, Belgium, the Netherlands, Luxembourg, France, Switzerland, Portugal, Italy, Spain, Greece, Malta, Germany, Denmark, Norway, Sweden, Finland, Latvia, Estonia, Czech Republic, and Iceland.^[31][32]

Spain

The first case of rabies since 1978 was confirmed in the city of Toledo, Central Spain, on 5 June 2013. The dog had been imported from Morocco. No human fatalities have been reported, although adults and children were reported to have been bitten by the animal.^[33]

Germany

Nine deaths from rabies were reported in Germany between 1981 and 2005. Two were caused by animal bites within Germany (one fox, one dog), and four were acquired abroad. In the remaining three cases, the source was a transplant from a donor who had died of rabies.^[34] On 28 September 2008, the World Organisation for Animal Health declared Germany as free of rabies.^[35]

Ireland

In 1897 the Disease of Animals Act included provisions to prevent the spread of rabies throughout Ireland. There have been no indigenous cases reported since 1903. In 2009, four people in Dublin received rabies vaccination therapy after being bitten by an imported kitten, although subsequent examination of the kitten yielded a negative result for rabies.^[36][37]

United Kingdom

The UK was declared rabies free in 1902 but there were further outbreaks after 1918 when servicemen returning from war smuggled rabid dogs back to Britain. The disease was subsequently eradicated and Britain was declared rabies-free in 1922 after the introduction of compulsory quarantine for dogs.^[34][38]

Since 1902, there have been 26 deaths in the UK from rabies (excluding the European bat lyssavirus 2 case discussed below).^[34][39] A case in 1902 occurred shortly before the eradication of rabies from the UK, and no details were recorded for a case in 1919.^[34] All other cases of rabies caused by rabies virus acquired the infection while abroad. Sixteen cases (62%) involved infections acquired in India, Pakistan or Bangladesh.^[34]

Since 2000, four deaths from rabies have occurred; none of these cases had received any post-exposure prophylactic treatment. In 2001, there were two deaths from infections acquired in Nigeria and the Philippines. One death occurred in 2005 from an infection acquired by a dog bite in Goa (western India).^[34][40] A woman died on 6 January 2009 in Belfast, Northern Ireland. She is believed to have been infected in South Africa, probably from being scratched by a dog.^{[41][42][43][44]} Prior to this, the last reported human case of the disease in Northern Ireland was in 1938.^[43][44] The most recent case was a woman who died on 28 May 2012 in London after being bitten by a dog in South Asia.^[45]

A rabies-like lyssavirus, called European bat lyssavirus 2, was identified in bats in 2003.^[40] In 2002, there was a fatal case in a bat handler involving infection with European bat lyssavirus 2; infection was probably acquired from a bite from a bat in Scotland.^[34][40]

Benelux

The Netherlands has been designated rabies-free since 1923, Belgium since 2008. Isolated cases of rabies involving illegally smuggled pets from Africa, as well as infected animals crossing the German and French borders, do occur.^[46]

Rabies-free jurisdictions, as of January 2006: Australia, New Zealand, Singapore, Fiji, Guam, Hawaii, the United Kingdom, Ireland, Belgium, the Netherlands, Norway, Sweden, Finland, Iceland, Japan, and Taiwan/ROC.

Oceania

Australia

Australia is free of rabies. There have been two confirmed human deaths from the disease, in 1987 and 1990. Both were contracted overseas.^[47] There is also a report of an 1867 case.^[48] There has been professional concern that the arrival of rabies in Australia is likely given its wide presence in Australian's neighbour Indonesia.^[49]

Rabies-free jurisdictions

Many countries and territories have been declared to be free of rabies. The Centers for Disease Control and Prevention published the following list based on countries and political units that reported no indigenous cases of rabies (excluding bat rabies) during 2009.

• Africa: Cape Verde, Libya, Mauritius, Réunion, São Tomé and Príncipe, and Seychelles
• Americas: Bermuda, St. Pierre and Miquelon, Antigua and Barbuda, Aruba, The Bahamas, Barbados, Cayman Islands, Dominica, Guadeloupe, Jamaica, Martinique, Montserrat, Netherlands Antilles, Saint Kitts (Saint Christopher) and Nevis, Saint Lucia, Saint Martin, Saint Vincent and Grenadines, Turks and Caicos, and Virgin Islands (UK and US)
• Asia and the Middle East: Hong Kong, Japan, Kuwait, Lebanon, Qatar, Singapore, United Arab Emirates.
  • Taiwan (ROC) lost its rabies-free status in June 2013, after three wild ferret-badgers were found positive to the virus.^[50][51]
  • Malaysia lost its rabies-free status in September 2015, after rabies outbreak in Perlis, Kedah and Penang.^[52]
• Europe: Austria, Belgium, Cyprus, Czech Republic, Denmark, Finland, Gibraltar, Greece, Iceland, Ireland, Isle of Man, Luxemburg, Netherlands, Norway, Portugal, Spain (except Ceuta and Melilla), Sweden, Switzerland, and United Kingdom
• Oceania: Australia, Cook Islands, Fiji, French Polynesia, Guam, Hawaii, Kiribati, Micronesia, New Caledonia, New Zealand, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, and Vanuatu

New Zealand and Australia have never had rabies. However, in Australia, the closely related 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. Rabies has also never been reported in Cook Islands, Jersey in the Channel Islands, mainland Norway, Saint Vincent and the Grenadines and Vanuatu.^[53]

References