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Epidemiology of rabies in Kenya. Philip M. Kitala 1 and Stella Kiambi 2 1 University of Nairobi Dept Public Health, Pharm and Toxi Email: pkitala@uonbi.ac.ke 2 Ministry of Livestock Development Zoonoses Disease Unit (ZDU) Email: gaichuki@yahoo.com. Epidemiology of rabies in Kenya.
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Epidemiology of rabies in Kenya Philip M. Kitala1 and Stella Kiambi2 1University of Nairobi Dept Public Health, Pharm and Toxi Email: pkitala@uonbi.ac.ke 2Ministry of Livestock Development ZoonosesDisease Unit (ZDU) Email: gaichuki@yahoo.com
Epidemiology of rabies in Kenya History of rabies • Rabies, an ancient disease, is well known in Kenya • 1st confirmed rabies case was in 1912 in a dog in the outskirts of Nairobi • 1st documented human rabies case was in 1928 in a woman from South Nyanza • Records kept by the Vet Dept shows that Kenya experienced rabies epidemics in early 1930s, late 1940s, and early 1950s
Epidemiology of rabies in Kenya… • Widespread deployment of an egg-adapted life virus vaccine in the 1950s and 1960s, effectively controlled rabies so that by 1973, the disease was virtually eliminated from the country • However, following an outbreak in late 1974 in Taita/Taveta, the rabies situation changed dramatically • By 1979,the disease had spread along the densely populated coastal strip and along the Tanzania border to Trans Mara, South Nyanza, and Western Kenya
Epidemiology of rabies in Kenya… • By end of 1982, rabies had spread throughout Nyanza, Western Province, Central Rift Valley, Nairobi and adjacent areas • To date rabies is more widespread and prevalent in Kenya than at any time in its history • By 1992, only 4 districts of the then 41 (10%), had no confirmed rabies cases
Epidemiology of rabies in Kenya… Figure 1: Distribution of confirmed animal rabies cases in Kenya, 2002 – March, 2013
Epidemiology of rabies in Kenya… Distribution of rabies cases by species • The domestic dog remains the principal reservoir and transmitter of rabies to both man and his other domestic animals in Kenya • From 1912 to end of May 1991, a total of 2931 animal specimens were confirmed positive with dogs accounting for 64.2% (1881) • Between 1983-1990, domestic dogs accounted for 63% of the 2149 animal rabies cases confirmed
Epidemiology of rabies in Kenya… • By contrast, of the 1034 animal specimens confirmed positive for rabies in the last ten years (2002-March 2013), dogs accounted for 46% of the positives and cattle 37%. • We believe this apparent decline in dog rabies prevalence is a reflection of weaknesses of the surveillance of rabies in recent years – suspected rabies in the more economically important dairy cattle are more likely to be reported by their owners relative to suspected dog rabies cases.
Epidemiology of rabies in Kenya… • Due to defective surveillance of rabies in the country these figures should only be taken as an indication of the rabies trend in the country and not a reflection of the true incidence of the disease and therefore rabies burden
Epidemiology of rabies in Kenya… Confirmed rabies cases by species in Kenya, 2002-March 2013
Epidemiology of rabies in Kenya… Rabies trend in Kenya, 2002-March 2013
Epidemiology of rabies in Kenya… • Role of wildlife in the epidemiology of rabies in Kenya remains unclear • The disease has been confirmed in the following wildlife species: Jackals Fox Mongoose (white-tailed) Hyena Genet cat Leopard Squirrel Monkey Honey badger Bat (Lagos bat virus, Shimoni bat virus) • The few wildlife rabies virus isolates so far typed have been found to be of the canid type (Africa 1b) – indicating transmission from dogs to wildlife
Epidemiology of rabies in Kenya… Human cases of animal bites • Over the last three years, a total of 318 456 cases of animal-bites were documented countrywide: 2010 ---------------- 38 944 2011 ---------------- 133 150 2012 ---------------- 146 362 • Assuming a human population of 40 million people, the crude estimate of animal-bite incidence for the three years: 2010 ---------------- 97 bites /100 000 population 2011 ----------------- 333 bites /100 000 population (3.4 times) 2013 ----------------- 366 bites /100 000 population (1.1 times) • Compare with incidence estimated for Machakos 1992/1993 of 234/100 000 population (97% by dogs) and for Tanzania in 2010 of 140/100 000 population
Epidemiology of rabies in Kenya… Human rabies cases • Information on numbers of confirmed human rabies cases in Kenya is scanty • True incidence of human rabies deaths in Kenya is grossly underestimated • Reasons for this are many in Africa: • Rabies victims are often too ill to travel to hospital or die before arrival; • Families recognize the futility of medical treatment for rabies
Epidemiology of rabies in Kenya… 3) Patients are considered to be the victims of bewitchment rather disease; 4) Clinically recognized cases at hospitals may go unreported to central authorities 5) Misdiagnosis is not uncommon
Epidemiology of rabies in Kenya… Spatial distribution of human rabies cases in Kenya, 2002-March 2013
Epidemiology of rabies in Kenya… Conclusions • The rabies burden in Kenya is likely to be substantial but its size and extent remains unknown • The domestic dog remains the principal reservoir and vector of rabies in the country • Past rabies control efforts have been ineffective • Rabies occurs over large parts of the country mainly due to a large, poorly supervised, and inadequately protected dog population by vaccination
Epidemiology of rabies in Kenya… What is lacking? • Better reporting of both rabies cases and dog bites in the country • Better communication between the veterinary and medical communities in terms of: • Outbreak reporting • Information flow • Joint vaccination programs • Budgets
Epidemiology of rabies in Kenya… • Scaled-up approach across wide regions rather than a one-off exercise • Big scale interventions over long periods of time, with annual vaccination of dogs • Centralized management • Commitment to a sustained budget • CAN IT BE DONE?
Epidemiology of rabies in Kenya… Vaccinateddogs (Millions)
Epidemiology of rabies in Kenya… • THANK YOU!
