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Rabies Biostatistical Data
Rabies Biostatistical Data
Roxanne Evans
Concordia University Nebraska
Rabies Biostatistical Data
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Approximately 2.5 billion people across 100 different countries are at risk for contracting rabies
with the majority, 99%, of rabies infections occurring in tropical developing countries. (Haupt,
1999) India, for example, has an estimated 20,000 human fatalities from rabies, this makes India
one of the highest contributors to the global rabies mortality rate. The high incidence of rabies in
India is likely due to the high incidence of dog bites, roughly 17.4 million annually. In India, the
incidence rate of contracting rabies is roughly 2.74 per 100,000 people annually. (Baxter, 2012)
Compared to other locations, like the United States which has an incidence rate of rabies
mortality approximately 0.001 per 100,000 people. (Haupt, 1999) The country with the highest
incidence rate, from data in 1999, was Ethiopia, 18 per 100,000 people. (Haupt, 1999) These
high incidence rates of rabies can be contributed to the lack of available vaccine for people,
either physical or financial, and the high populations of stray dogs in these poor countries. Lack
of education also plays a role, as well as poor hygiene, in the spread of the rabies virus. (Rabies,
2014)
Post-exposure prophylaxis has the highest rate of use in children between the ages of 5 and 14
years old, approximately 40 %. (Rabies, 2014) The WHO also reports that the majority of these
children are male. Children are likely at higher risk due to lack of fear and increased curiosity.
(Rabies, 2014)
Travelers to endemic rabies countries also have a higher incidence of contracting the disease than
those traveling to rabies free countries. Countries like New Zealand, have never had rabies in
their country. It is also very possible for travelers to contract the virus in an endemic area and
not show symptoms until they are back in their home country, which may be rabies free, as
Carrara et al described in their 2013 review of imported rabies cases. They collected 60 cases of
Rabies Biostatistical Data
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rabies where the individual likely contracted the disease in a different country. For example, an
individual in 2008 contracted rabies in India, but was diagnosed with the disease in Ireland,
which is a rabies free country. (Carrara, Parola, Brouqui, & Gautret, 2013)
Due to the variable incubation period, of less than 1 week to greater than 1 year, travelers are
able to return home before knowing they might be sick. (Rabies, 2014) In addition, rabies
clinical symptoms can be difficult to recognize if an indivual is not educated about the syptoms.
Though finding the exact number of misdiagnosed cases of rabies is impossible, the fact remains
they exsist. A recent example would be of a Maryland man who received a kidney trasplant from
a 20 year old man who died of an unknown encepalitis in 2011. The Maryland man contracted
rabies from his new kidney and also died of the disease. Suspected exposure is not listed for the
donor. (Cohen & Bonifield, 2013)
Rabies virus can show two forms seen in infected humans, the furious form and the paralytic
form. The furious form of rabies typically causes hypersensitivity, agitation, hydrophobia and
aerophobia, and cause of death is usually cardio-respiratory arrest. (Rabies, 2014) The paralytic
form of rabies is described as a slow progressive muscle paralysis leading to coma and death.
According to the WHO, approximately 30% of all human rabies case are the paralytic form. This
is form of rabies is also the most likely to be missed diagnosed for an unknown encephalitis in
absence of a known animal bite. (Rabies, 2014) It's also been documented that rabies has been
transmitted through organ donation of individual who have died of unknown encephalopathy.
(Carrara, Parola, Brouqui, & Gautret, 2013)
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References
Baxter, J. M. (2012, June). One in a million, or one in thousand: What is the morbidity of rabies in India?
Journal of Global Health, 2(1), 010303. doi:10.7189/jogh.02.010303
Carrara, P., Parola, P., Brouqui, P., & Gautret, P. (2013, May 2). Imported Human Rabies Cases
Worldwide, 1990-2012. PLOS Medicine Journal. doi:10.1371/journal.pntd.0002209
Cohen, E., & Bonifield, J. (2013, March 15). CDC: Man died of rabies from kidney transplant. Retrieved
September 18, 2014, from CNN.com: http://www.cnn.com/2013/03/15/health/organtransplant-rabies-death/
Haupt, W. (1999, March 26). Rabies - risk of exposure and current trends in prevention of human cases.
Vaccine, 17(13-14), 1742-9. doi:10.1016/s0264-410x(98)00447-2
Rabies. (2014). Retrieved September 2, 2014, from World Health Organization:
http://www.who.int/mediacentre/factsheets/fs099/en/