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Prevention and control of rabies in animals and humans in Ethiopia
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Livestock losses due to rabies and health and the corresponding benefits of controlling the disease are not often considered when the cost-effectiveness of rabies control is evaluated. In this research, assessed the benefits of applying a One Health perspective that includes these losses to the case of canine rabies vaccination in Ethiopia. We constructed a dynamic epidemiological model of rabies transmission. The model was fit to district-specific data on human rabies exposures and canine demography for two districts with distinct agro-ecologies. The epidemiological model was coupled with human and livestock economic outcomes to predict the health and economic impacts under a range of vaccination scenarios. The model indicates that human exposures, human deaths, and rabies-related livestock losses would decrease monotonically with increasing vaccination coverage. In the rural district, all vaccination scenarios were found to be cost-saving compared to the status quo of no vaccination, as more money could be saved by preventing livestock losses than would be required to fund the vaccination campaigns. Vaccination coverages of 70% and 80% were identified as most likely to provide the greatest net health benefits at the WHO cost-effectiveness threshold over a period of 5 years, in urban and rural districts respectively. Shorter time frames led to recommendations for higher coverage in both districts, as did even a minor threat of rabies re-introduction. Exclusion of rabies-related livestock losses reduced the optimal vaccination coverage for the rural district to 50%. This study demonstrated the importance of including all economic consequences of zoonotic disease into control decisions. Analyses that include cattle and other rabies-susceptible livestock are likely better suited to many rural communities in Africa wishing to maximize the benefits of canine vaccination.
Rabies has one of the highest case-fatality ratios of any infectious disease, almost always fatal, caused by lyssavirus infection. It is associated with dysfunction of the neurons after the entrance of rabies virus to the central nervous system, usually in the spinal cord. The bite route is still regarded as the most important means of transmission. Although wild animals are regarded as a host for rabies, dogs and cats remain the most important sources of human exposure. The disease is worldwide in distribution except in Antarctica. The most affected regions are tropical countries in Africa, Asia and South America, which have limited resources for diagnosis, treatment, control surveillance and vaccine production and improvement. Controlling rabies is challenging, due to wide host range and worldwide distribution, availability of many free roaming/stray dogs and lack of awareness about the disease. Diagnosis of the rabies is one of the most difficult duties because of non-specific clinical symptoms, long incubation period and limited diagnostic techniques. Vaccines are expensive and consequently, out of the reach for many people. Apart from high cost and unavailability, they are associated with serious neurologic complications. The economic costs of rabies in a country are associated with vaccinations, laboratory diagnosis, treatment and public education. So, the main objectives of this paper are to highlight the general characteristics of rabies virus, indicate the overall course of rabies and review possible challenges of rabies.
Background
Rabies still poses a significant health problem in most of African countries, where the majority of the cases result from dog bites. The situations in the marginalized pastoral areas were not well documented.
Case
In September 2015, rabid wild fox entered the pastoralist village and bit a domestic dog. The victim dog had turned rabid after four months and bit livestock, and rabies outbreak occurred in the family livestock. Consequently, one bull, one lactating cow, one calf, two donkeys and one heifer died of outbreak. The head of one heifer was removed and transported within 24 hours to the Rabies Referral Laboratory of Ethiopian Public Health Institute in Addis Ababa. The sample was confirmed as strong positive for lyssa virus antigen by Direct Fluorescent Anti-Body Test. This was the first confirmed case report from southern Oromia pastoralists. The occurrence of rabies cases across the district was also reported by veterinary and human health officers.
Conclusion
Integrated intervention strategy and collaboration of animal health, human health and wildlife authority is needed. To halt the ongoing outbreak in the district, immediate response from the Government is recommended.
In developing countries where financial resources are limited and numerous interests compete, there is a need for quantitative data on the public health burden and costs of diseases to support intervention prioritization. This study aimed at estimating the health burden and post-exposure treatment (PET) costs of canine rabies in Ethiopia by an investigation of exposed human cases. Data on registered animal bite victims during the period of one year were collected from health centers in three districts, i.e. Bishoftu, Lemuna-bilbilo and Yabelo, to account for variation in urban highland and lowland areas. This data collection was followed by an extensive case search for unregistered victims in the same districts as the registered cases. Victims were visited and questioned on their use of PET, incurred treatment costs and the behavioral manifestations of the animal that had bitten them. Based on the collected data PET costs were evaluated by financial accounting and the health burden was estimated in Disability-Adjusted Life Years (DALYs). In total 655 animal bite cases were traced of which 96.5% was caused by dog bites. 73.6% of the biting dogs were suspected to be potentially rabid dog. Annual suspected rabid dog exposures were estimated per evaluated urban, rural highland and rural lowland district at, respectively, 135, 101 and 86 bites, which led, respectively, to about 1, 4 and 3 deaths per 100,000 population. In the same district order average costs per completed PET equaled to 23, 31 and 40 USD, which was significantly higher in rural districts. Extrapolation of the district results to the national level indicated an annual estimate of approximately 3,000 human deaths resulting in about 194,000 DALYs per year and 97,000 exposed persons requiring on average 2 million USD treatment costs per year countrywide. These estimations of the burden of rabies to the Ethiopian society provide decision makers insights into the potential benefits of implementing effective interventions.
Background
Ethiopia has the second largest human population in Africa and the largest livestock population on the continent. About 80% of Ethiopians are dependent on agriculture and have direct contact with livestock or other domestic animals. As a result, the country is vulnerable to the spread of zoonotic diseases. As the first step of the country's engagement in the Global Health Security Agenda, a zoonotic disease prioritization workshop was held to identify significant zoonotic diseases of mutual concern for animal and human health agencies.
Methods
A semi-quantitative tool developed by the US CDC was used for prioritization of zoonotic diseases. Workshop participants representing human, animal, and environmental health ministries were selected as core decision-making participants. Over 300 articles describing the zoonotic diseases considered at the workshop were reviewed for disease specific information on prevalence, morbidity, mortality, and DALYs for Ethiopia or the East Africa region.
Committee members individually ranked the importance of each criterion to generate a final group weight for each criterion.
Results
Forty-three zoonotic diseases were evaluated. Criteria selected in order of importance were: 1)severity of disease in humans, 2)proportion of human disease attributed to animal exposure, 3)burden of animal disease, 4)availability of interventions, and 5)existing inter-sectoral collaboration. Based on the results from the decision tree analysis and subsequent discussion, participants identified the following five priority zoonotic diseases: rabies, anthrax, brucellosis, leptospirosis, and echinococcosis.
Discussion
Multi-sectoral collaborations strengthen disease surveillance system development in humans and animals, enhance laboratory capacity, and support implementation of prevention and control strategies. To facilitate this, the creation of a One Health-focused Zoonotic Disease Unit is recommended. Enhancement of public health and veterinary laboratories, joint outbreak and surveillance activities, and intersectoral linkages created to tackle the prioritized zoonotic diseases will undoubtedly prepare the country to effectively address newly emerging zoonotic diseases.
Rabies is a neglected zoonotic disease which kills up to 60,000 people a year, most of them in Africa and Asia. In the majority of developing countries, the number of patients receiving post exposure prophylaxis has steadily increased over time, particularly in urban areas due to dog related rabies. Studies conducted in sub-Saharan Africa show that most of the rabies cases in animals and humans are caused by canine rabies virus, mostly transmitted by domestic dogs and thus comprehensive and sustained dog vaccination is sufficient intervention in reduction and eventual elimination of human rabies in the region. In many developing countries, progress in preventing human rabies through control of the disease in the dog reservoir were slow due to technical, intersectoral, organizational and financial barriers. For developing countries like Ethiopia, strategy should be developed to prevent and control the disease. Sustainable resources for effective dog vaccination are likely to be available through the development of intersectoral financing schemes involving both medical and veterinary sectors. Prevention of animal rabies through dog vaccination, better public awareness, improved access to cost-effective and high-quality human rabies vaccines, and improved local capacity in rabies surveillance and diagnostics are essential for the elimination of human rabies. Generally, elimination of canine rabies is epidemiologically and practically feasible through mass vaccination of domestic dogs which is cost-effective approach to the prevention and elimination of human rabies deaths. The purpose of this paper is to show the burden of the disease and to give direction for effective prevention and control following developed countries experience.
Reliable data is required on diseases like rabies by policy makers and professionals. This study was therefore aimed at assessing the situation of rabies in and around Addis Ababa using retrospective data obtained during 2008 to 2011. Besides, a questionnaire was used to generate information on factors associated with the occurrence of rabies. A total of 935 brain samples from different species of animals were examined for rabies virus antigen during 2008 to 2011, of which 77.6% (n = 726) of them were tested positive. The highest proportion, 87.2% (n = 633) of the positive cases, was recorded in dogs followed by cats, 5.1% (n = 37). Between the years 2008 and 2011, a total of 1,088 dogs were examined for rabies, of which 801 (73.62%) were confirmed to be rabid. The proportion of rabid female dogs (87.5%) was higher than that of males (73.44%), and dogs 3 to 12 months old were diagnosed with rabies more frequently (76.6%) than dogs belonging to other age category. The highest proportion of rabid dogs was recorded in dogs whose ownership was not known followed by ownerless dogs. Rabies cases were confirmed both in vaccinated and non-vaccinated dogs. The number of confirmed rabies cases was higher during September and lower during November. Significant variation was seen among years in occurrence of rabies. The study shows that the principal vector of rabies in Addis Ababa and its surroundings, but most likely in entire Ethiopia, is the dog. Effective rabies management and control based on confirmed cases is recommended.
Key words: Dog, Ethiopia, post-exposure prophylaxis, rabies.
Rabies is a notoriously underreported and neglected disease of low-income countries. This study aims to estimate the public health and economic burden of rabies circulating in domestic dog populations, globally and on a country-by-country basis, allowing an objective assessment of how much this preventable disease costs endemic countries.
We established relationships between rabies mortality and rabies prevention and control measures, which we incorporated into a model framework. We used data derived from extensive literature searches and questionnaires on disease incidence, control interventions and preventative measures within this framework to estimate the disease burden. The burden of rabies impacts on public health sector budgets, local communities and livestock economies, with the highest risk of rabies in the poorest regions of the world. This study estimates that globally canine rabies causes approximately 59,000 (95% Confidence Intervals: 25-159,000) human deaths, over 3.7 million (95% CIs: 1.6-10.4 million) disability-adjusted life years (DALYs) and 8.6 billion USD (95% CIs: 2.9-21.5 billion) economic losses annually. The largest component of the economic burden is due to premature death (55%), followed by direct costs of post-exposure prophylaxis (PEP, 20%) and lost income whilst seeking PEP (15.5%), with only limited costs to the veterinary sector due to dog vaccination (1.5%), and additional costs to communities from livestock losses (6%).
This study demonstrates that investment in dog vaccination, the single most effective way of reducing the disease burden, has been inadequate and that the availability and affordability of PEP needs improving. Collaborative investments by medical and veterinary sectors could dramatically reduce the current large, and unnecessary, burden of rabies on affected communities. Improved surveillance is needed to reduce uncertainty in burden estimates and to monitor the impacts of control efforts.
Canine rabies, responsible for most human rabies deaths, is a serious global public health concern. This zoonosis is entirely preventable, but by focusing solely upon rabies prevention in humans, this "incurable wound" persists at high costs. Although preventing human deaths through canine rabies elimination is feasible, dog rabies control is often neglected, because dogs are not considered typical economic commodities by the animal health sector. Here, we demonstrate that the responsibility of managing rabies falls upon multiple sectors, that a truly integrated approach is the key to rabies elimination, and that considerable progress has been made to this effect. Achievements include the construction of global rabies networks and organizational partnerships; development of road maps, operational toolkits, and a blueprint for rabies prevention and control; and opportunities for scaling up and replication of successful programs. Progress must continue towards overcoming the remaining challenges preventing the ultimate goal of rabies elimination.
To quantify the public health and economic burden of endemic canine rabies in Africa and Asia.
Data from these regions were applied to a set of linked epidemiological and economic models. The human population at risk from endemic canine rabies was predicted using data on dog density, and human rabies deaths were estimated using a series of probability steps to determine the likelihood of clinical rabies developing in a person after being bitten by a dog suspected of having rabies. Model outputs on mortality and morbidity associated with rabies were used to calculate an improved disability-adjusted life year (DALY) score for the disease. The total societal cost incurred by the disease is presented.
Human mortality from endemic canine rabies was estimated to be 55 000 deaths per year (90% confidence interval (CI) = 24 000-93 000). Deaths due to rabies are responsible for 1.74 million DALYs lost each year (90% CI = 0.75-2.93). An additional 0.04 million DALYs are lost through morbidity and mortality following side-effects of nerve-tissue vaccines. The estimated annual cost of rabies is USD 583.5 million (90% CI = USD 540.1-626.3 million). Patient-borne costs for post-exposure treatment form the bulk of expenditure, accounting for nearly half the total costs of rabies.
Rabies remains an important yet neglected disease in Africa and Asia. Disparities in the affordability and accessibility of post-exposure treatment and risks of exposure to rabid dogs result in a skewed distribution of the disease burden across society, with the major impact falling on those living in poor rural communities, in particular children.
More than 50,000 people die of rabies each year; most are children in developing countries, and almost all have been bitten by dogs. Eliminating canine rabies throughout the world would save thousands of lives and would reduce the economic impact of the disease by dramatically reducing the requirement for postexposure prophylaxis (PEP). Lengthy experience in the industrialized countries and ongoing programs in Latin America, Africa, and Asia have shown that the elimination of rabies in dogs is an achievable goal. The presence of canine rabies in developing countries is associated with poverty, and most deaths occur in the lowest socioeconomic sectors. To be successful, national rabies control programs should share responsibility with local communities for prevention and control activities and maintaining disease-free status. Legislation should be adapted to local conditions and the realities of dog ownership. While the provision of PEP to all bite victims is affordable in many countries, it is usually beyond the capacity of impoverished nations, which deal with many other health priorities. Ministries of health should provide PEP, either free or with a charge preferably at a subsidized price, replacing the current system in many countries, in which biologics are sold by government-owned and private clinics at a cost beyond the means of bite victims. The public health sector should assume responsibility when animal control strategies are not effectively implemented or when PEP is not administered correctly or is not available. A global strategy is needed to identify gaps in surveillance and diagnosis, improve access to PEP and enhance canine immunization and population management. Such approaches based on a "One Health" model should be coordinated across regions, and should extend control efforts to other dog-related zoonoses. This article introduces a symposium in Antiviral Research on the elimination of canine rabies.
Most dogs experimentally infected with street rabies virus showed clinical signs of rabies before death, but up to 18% of
the dogs died without showing detectable signs of illness. In dogs showing signs, rabies was not invariably fatal. Up to 20%
of dogs recovered without any supportive treatment. Some dogs inoculated with American (southern Texas) or Ethiopian canine
street virus excreted virus in their saliva up to 14 days before signs appeared. There was no relation between the time of
excretion of virus in the saliva and the titer of virus in the salivary glands at death. One dog that recovered from rabies
intermittently excreted rabies virus in its saliva for a long time. The carrier state in rabies may playa significant role
in the perpetuation and survival of the virus and may become a source for rabies outbreaks whenever a new generation of rabies
susceptibles reaches critical density.
Thirty-nine dogs were injected intramuscularly with either an Ethiopian strain or a
Mexican strain of rabies virus. The excretion of rabies virus in the saliva was studied
before and during illness. Nine of 17 dogs that died after injection with the Ethiopian
strain had virus in the submaxillary glands. Four of these dogs excreted virus in the
saliva up to 13 days before signs of disease were observed. Sixteen of 22 dogs that died
after injection with the Mexican strain had virus in the submaxillary glands. Eight of
these dogs also excreted virus in the saliva up to seven days before signs of disease were
observed. These findings indicate that rabid dogs may excrete virus in their saliva much
earlier than previously reported.
Rabies is inevitably fatal and presents a horrifying clinical picture. Human rabies can manifest in either encephalitic (furious) or paralytic (dumb) forms. The brainstem is preferentially involved in both clinical forms, though there are no clinical signs of brainstem dysfunction. Differences in tropism at the inoculation site or the CNS, in the route of spread, or in the triggering of immune cascades in the brainstem may account for clinical variation. Rabies still poses diagnostic problems, particularly the paralytic form, which closely resembles Guillain-Barré syndrome, or when a patient is comatose and cardinal signs may be lacking. Molecular methods allow reliable detection of rabies-virus RNA in biological fluids or tissue before death. Deviations from the recommendations on prophylaxis of the World Health Organization lead to unnecessary loss of life. To date, attempts to treat human rabies have been unsuccessful.
Major challenges and gaps in rabies prevention and control
- A Abebe
Abebe, A. (2012): Major challenges and gaps in rabies
prevention and control. In: Proceedings of the national
workshop on rabies prevention and control in Ethiopia,
October 18-19, 2012, Adama, Ethiopia, Pp. 35.
- A Ali
- F Mengistu
- K Hussen
- G Getahun
- A Deressa
Ali, A., Mengistu, F., Hussen, K., Getahun, G. and Deressa,
A. (2010): Overview of rabies in and around Addis Ababa, in
animals examined in EHNRI zoonoses laboratory between,
2003 and 2009. Ethiopian Veterinary Journal, 14(2):91-101.
Guidelines for dog population management. World Health Organization and World Society for the Protection of Animals
- K Bogel
- J A Hoyte
Bogel, K. and Hoyte, J.A. (1990): Guidelines for dog
population management. World Health Organization and
World Society for the Protection of Animals.
Geneva, Switzerland.
Compendium of animal rabies prevention and control. National association of state public health veterinarians
CDC (2011): Compendium of animal rabies prevention and
control. National association of state public health
veterinarians, Inc. Morbidity and Mortality Weekly Report,
60(6):1-18.
- S Cleaveland
- M Kaare
- P Tiringa
- T Mlengeya
- J Barrat
Cleaveland, S., Kaare, M., Tiringa, P., Mlengeya, T. and
Barrat, J. (2003): A dog rabies vaccination campaign in rural
Africa: impact on the incidence of dog rabies and human dogbite injuries. Vaccine,21(17-18):1965-1973.
- A Deressa
- A Ali
- M Beyene
- B Newayeselassie
- E Yimer
Deressa, A., Ali, A., Beyene, M., Newayeselassie, B. and
Yimer, E. (2010): The status of rabies in Ethiopia: A
retrospective record review. Ethiopian Journal of Health
Development, 24(2):127-132.
Epidemiology, prevention and control methods of rabies in domestic animals: Review article
- N Moges
Moges, N. (2015). Epidemiology, prevention and control
methods of rabies in domestic animals: Review article.
European Journal of BiologicalSciences,7(2):85-90.
- M Pal
- A Hailu
- R K Agarwal
- P Dave
Pal, M., Hailu, A., Agarwal, R.K. and Dave, P. (2013):
Recent developments in the diagnosis of rabies in humans
and animals. JournalVeterinaryPublic Health,11(2):77-82.
Human rabies surveillance in Ethiopia
- H Taame
Taame, H. (2012). Human rabies surveillance in Ethiopia. In:
Proceedings of the national workshop on rabies prevention
and control in Ethiopia, October 18-19, 2012, Adama,
Ethiopia, Pp. 15.
Contro l and prevention of rabies through dog vaccination campaig ns, public awareness creation and dog population control
- M H Taame
- B H Abrha
- T A Yohannes
- T G Abreha
- T R Yisehak
- N H Guesh
- G T Berihu
Taame, M.H., Abrha, B.H., Yohannes, T.A., Abreha, T.G.,
Yisehak, T.R., Guesh, N.H. and Berihu, G.T. (2017): Contro
l and prevention of rabies through dog vaccination campaig
ns, public awareness creation and dog population control. Et
hiopian Journal of Veterinary Science
and
Animal
Production (EJVSAP), 1(1):9-16.
Rabies vaccines: WHO position paper
WHO (2010): Rabies vaccines: WHO position paper. Weekl
y Epidemiological Record, 85:309−320.
- E Yimer
- B Newayeselassie
- G Teferra
- Y Mekonnen
- Y Bogale
- B Zewde
- M Beyene
- A Bekele
Yimer, E., Newayeselassie, B., Teferra, G., Mekonnen, Y.,
Bogale, Y., Zewde, B., Beyene, M. and Bekele, A. (2002):
Situation of rabies in Ethiopia: a retrospective study 1990-2000. Ethiopian Journal of Health Development,16(1):105-112.
Transmission dynamics and economics of rabies control in dogs andhumans in an African city
- J Zinsstag
- S Durr
- M A Penny
- R Mindekem
- F Roth
- S M Gonzalez
- S Naissengar
- J Hattendorf
Zinsstag, J., Durr, S., Penny, M.A., Mindekem, R., Roth, F.,
Gonzalez,
S.M.,
Naissengar,
S.and Hattendorf,
J. (2009): Transmission dynamics and economics of rabies
control in dogs andhumans in an African city. Proceedings of
the national academy of science of the USA,106(35):14996-