Review on Economic Importance’s of Rabies in Developing Countries and Its Controls

Rabies is a zoonotic viral disease of mammals most often transmitted through the bite of a rabid animal. Warm blooded animals are susceptible to infection with rabies virus and are therefore possible reservoirs. Dogs are the main reservoir of rabies virus in developing countries and are responsible for 99% of human infections. Even though developed countries have been able to contain recent outbreaks of zoonotic diseases, many resource-limited and transitioning countries have not been able to react adequately. Rabies remains a global zoonosis of major public health, agricultural and economic signifi cance. It cause many economic loses in many developing country. Rabies transmitted by dogs is responsible for the loss of over 1.8 million DALYs (disability adjusted life years) every year, with direct and indirect economic costs (PEP, animal tests, dog vaccination, and livestock losses) totaling $5.5 billion per year. In addition to that its effects also included the costs associated with the risk of human mortality, resulted in a global cost for canine rabies of $120 billion. These virus disease result in about 24,000 to 60,000 deaths worldwide per year. More than 95% of human deaths caused by rabies occur in Africa and Asia. For instance thousands of people are infected with rabies in Ethiopia, and an estimated 2,700 people die each year—one of the highest rates in the world. Even though total number of animal burden is unknown, but healthcare workers and scientists confi rmed thousands of cases of rabies in dogs in Addis Ababa (the country’s capital) region alone. Rabies is present in more than 150 countries and on all continents but Antarctica. To mitigate those economic loss due to rabies, it is important to prevent through use of vaccine and environmental management. Review Article Review on Economic Importance’s of Rabies in Developing Countries and Its Controls Gemechu Regea* Jimma University College of Agriculture and Veterinary Medicine, School of veterinary medicine, Ethiopia Dates: Received: 27 March, 2017; Accepted: 17 April, 2017; Published: 24 April, 2017 *Corresponding author: Gemechu Regea, Jimma University College of Agriculture and Veterinary Medicine, School of veterinary medicine, Ethiopia, Tel: +251935732810; E-mail:


Introduction
Tb, Mastitis, lameness, metabolic abnormalities and other diseases affect many developing countries' animals are many times more prevalent than rabies. However, rabies is all but 100% fatal in humans and animals; it can be transmitted from animals to humans, making it a very important disease to recognize [1]. Rabies is a rapidly progressive and uniformly fatal viral cause's encephalitis caused by the bullet-shaped viral particles of the rabies group of Rhabdoviridae, genus Lyssavirus whose nucleus is RNA [2]. It causes infl ammation of the brain in humans and other mammals. Early symptoms can include fever, tingling at the site of exposure, anorexia and change in behavior [3].
These symptoms are followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness [3].Once symptoms appear, the result is nearly always death [3]. It transmissible disease among animals and animals to human. It causes economic loses directly or indirectly on local and national economy.

Etiology and epidemiology
Rabies is caused by lyssaviruses in the Rhabdovirus family. Lyssaviruses are usually confi ned to one major reservoir species in a given geographic area, although spillover to other species is common. Identifi cation of different virus variants by laboratory procedures such as monoclonal antibody analysis or genetic sequencing has greatly enhanced understanding of rabies epidemiology. Generally, each virus variant is responsible for virus transmission between members of the same species in a given geographic area. To date, >15 different lyssaviruses have been described. Globally, rabies virus is the most important member of the genus.
From an epidemiologic perspective, the name of the mammalian species acting as the reservoir and vector is used as an adjective to describe involvement in the infection process. For example, rabies maintained by dog-to-dog transmission is termed canine rabies, whereas rabies in a dog as a result of infection with a variant from a different reservoir mammal, eg, skunk (or raccoon or fox), would be referred to as skunk (or raccoon or fox, etc) rabies in a dog [4]. The rabies virus is present on all continents except Antarctica. Some countries have implemented vigilant control measures and succeeded in eradicating the disease to meet the OIE requirements for rabies free status. However, in some countries, the disease remains endemic with rabies present mainly in wild animal hosts Although the infection of domestic livestock could have economic consequences in some countries, it is the occurrence of rabies in domestic dogs posing a threat to humans that is of major concern in several developing and in-transition countries ([PDF]Rabies -OIE).

Clinical description
Rabies is an acute encephalomyelitis that almost always progresses to coma or death within 10 days after the fi rst symptom. Early recognition depends on eliciting a history of a bite or other contact with a possibly infected mammal, most commonly in dog rabies endemic areas of Asia, Africa or South America. There is a wide range of non-specifi c prodromal symptoms, so rabies patients have presented to rheumatologists, neurologists, psychiatrists, cardiologists, respiratory and acute medicine physicians, ear, nose and throat specialists, general and transplant surgeons and GPs [5]. It includes, Paresis or paralysis, delirium, convulsions. Without medical attention, death in about 6 days, usually caused by respiratory paralysis.

Diagnosis of rabies: Laboratory tests of secretions and
biological fl uids such as saliva, spinal fl uid, tears, and tissues may be used to diagnose rabies [6]. Laboratory techniques are preferably conducted on central nervous system (CNS) tissue removed from the cranium. The most widely used test for rabies diagnosis is the FAT, which is recommended by both WHO and OIE. This test may be used directly on a smear, and can also be used to confi rm the presence of rabies antigen in cell culture or in brain tissue of mice that have been inoculated for diagnosis (Shankar, B. P, 2009).
Detection by FAT on skin biopsy (ante mortem). FAT positive after inoculation of brain tissue, saliva or CSF in cell culture, or after intracerebral inoculation in mice or in suckling mice. Detectable rabies-neutralizing antibody titer in the serum or the CSF of an unvaccinated person. Detection of viral nucleic acids by PCR on tissue collected post mortem or intra vitam in a clinical specimen (brain tissue or skin, cornea, urine or saliva) (www. who. Int). RABV was isolated through intracerebral inoculation of suckling mice or by addition of suspensions of brain or saliva specimens to cultured mouse neuroblastoma cells, as described previously (Noah, 1998).

Dimention to economic impacts of rabies
Like all zoonotic diseases, rabies is maintained in an animal reservoir. In developed countries, where canine rabies has been eliminated, the virus may continue to circulate in wildlife, whereas in most developing countries the principal reservoir is domestic dogs. Human and livestock exposure is based on a multitude of risk factors (Zinsstag et al., 2007) [7].
Dog vaccination status is of paramount importance and while it represents a cost (indicated by the shaded box), it minimizes or eliminates further economic impact. In contrast, unvaccinated dogs, or dogs whose vaccination status is unknown, represent a pathway to further economic impacts. If the vaccination status of a dog can be readily determined, the initial cost of vaccination negates any further downstream impacts, but when humans and livestock are exposed to a dog that might have rabies, or whose vaccination status is unknown, further costs may be in curred. Livestock vaccination also represents an up-front cost, without further impacts, while unvaccinated, exposed animals will either not become infected, or will die from rabies. Similarly, there are two pathways following human exposure: the individual either seeks medical treatment and is given PEP, incurring direct and indirect costs [8], or he does not receive PEP, and either remains well or dies from rabies, leading to further costs. In Ethiopia, Rabies incidence rates of 21% and 11% at herd level were calculated for the mixed croplivestock and pastoral production systems, respectively [9]. surveillance and the lack of reliable data on the number of rabies cases is a major constraint to assessing the economic impact of rabies on the local economies when livestock and working animals die due to rabies or infect humans. In addition, the need to pay for transport and expensive postexposure prophylaxis for rabies exposed family or community members can lead to the unplanned sale of production animals and livelihoods assets, further impacting food and economic security.  (Table 1) [10,11].

On tourism, recreation and wild life conservation:
Rabies threatens many species with disease epidemics drastically reducing population's numbers. Ethiopian wolves, There is no doubt that canine rabies control has the potential for enormous public health benefi ts, not only reducing the number of human rabies deaths, but also the demand for costly post-exposure prophylaxis. However, control of animal rabies also has broader societal impacts, with benefi ts for both human and animal populations affected by the disease.
Rabies is a disease that elicits great fear and distress, both as a result of uncertainties faced by those requiring post-exposure prophylaxis in impoverished and remote rural communities, and as a result of the psychological trauma involved in managing human rabies cases. More recently, rabies has become a concern for the tourism industry with travel advisories issued in countries experiencing a reintroduction of rabies or on-going endemic disease. Imported cases of human rabies, although rare, highlight a continuing lack of awareness among travelers of the disease risk in canine rabies-endemic countries.
Additional impacts of animal rabies control include benefi ts for animal welfare, with improved attitudes and treatment of dogs, and benefi ts for wildlife conservation, with mass dog vaccination recommended as part of conservation strategies for wild carnivore populations threatened by canine rabies.
Awareness of the multiple benefi ts of animal rabies control not only provides added justifi cation for rabies control initiatives, but also broadens the constituency for support, offering the potential for developing integrated control measures that involve veterinary public health, tourism, wildlife conservation and animal welfare agencies. had also reported 12 cases per million people which made Ethiopia the second worse affected by rabies next to India [13] .  America are much lower than in Africa and Asia, probably as a direct result of coordinated efforts by many countries in the region to eliminate canine rabies [14], which also explains the

Macroeconomic impacts
The rabies burden is made up of different components. Human and livestock deaths from rabies and the cost of PEP produce regional macroeconomic impacts, including changes in income and employment, which arise from multiple sources.

Costs and cost-effectiveness of control measures
Attempts to build support for more widespread investment in rabies control require an appreciation of the current economic costs infl icted by rabies, the cost of control measures, and the potential benefi ts of those control measures [16]. In Latin America vaccination campaigns are one of the primary factors that have reduced human death, while in Africa the lack of dog vaccination is one of the main factors behind the high human death rate. The benefi ts of eliminating the disease extend beyond persons directly exposed to rabid dogs, to everyone in the community. Understanding the economic impact of canine rabies and the benefi ts that can be achieved by its elimination is central to the effective cooperation of health sectors. Taking data for each country from the recent global burden reassessment, it is possible to compare the pattern of burdens and costs across the three main endemic regions for canine rabies (Table 2). Africa suffers the highest per capita rate of human deaths of the three continents. Death rates are lower in Asia, due to substantial investment in the provision of PEP, but overall deaths are higher. Finally, investment in dog vaccination in Africa and Asia is not high enough to create the level of coverage that has been shown to be effective at reducing rabies exposures in Latin America in recent years.

Rabies control and prevention
The mortality rate of rabies is extremely high. Due to no proven standard therapy, current Rabies, an invariably fatal disease, has been known and feared since antiquity and is usually caused by the bite of an infected animal. More than 98% of all human rabies deaths are caused by the bite(s) of rabid dogs. Rabies is distributed worldwide and can affect all mammals including humans. The virus responsible for rabies infects the central nervous system resulting in a neurological disorder characterized by horrifi c clinical signs and symptoms in both animals and humans.
The majority of human rabies deaths globally occur as a result of being bitten by dogs. However, reliable data indicating the actual incidence of human rabies exposure are scarce or non-existent in many countries, leading to the widespread belief that the global number of human deaths is signifi cantly underreported. As a result, rabies impacts are often considered insignifi cant by policymakers, which ultimately results in inadequate political pressure to implement disease control measures. It is estimated that approximately 74,000 people die annually as a result of canine rabies, and most victims are children on the continents of Asia, Africa, and Latin America [15] .
Prevention of rabies in humans is complicated because those most commonly exposed to canine rabies (e.g., children, the poor) also lack the resources necessary to treat or prevent exposure. This means that governments, and other organizations are often the primary source of funding for the required post exposure prophylaxis (PEP).
Rabies transmitted by dogs is responsible for the loss of over 1.8 million DALYs (disability adjusted life years) every year, with direct and indirect economic costs (PEP, animal tests, dog vaccination, and livestock losses) totaling $5.5 billion per year. [15]. study another economic analysis, which also included the costs associated with the risk of human mortality, resulted in a global cost for canine rabies of $120 billion. [17]. Rabies also threatens the survival of endangered wildlife species. Controlling rabies is critically important to prevent human deaths and alleviate its burden in animal species and on local and national economies.

Preexposure vaccination and management:
Adherence to a regular rabies vaccination schedule is critical to protect animals against recognized and unrecognized rabies exposures. Parenteral animal rabies vaccines should be administered only by or under the direct supervision of a licensed veterinarianon premises. Rabies vaccines may be administered under the supervision of a licensed veterinarian to animals held in animal shelters before release. The veterinarian signing a rabies vaccination certifi cate must ensure that the person who administered the vaccine is identifi ed on the certifi cate and has been appropriately trained in vaccine storage, handling, and administration and in the management of adverse events. This ensures that a qualifi ed and responsible person can be held accountable for properly vaccinating the animal [18].
Pre-exposure vaccination may be offered to high risk groups like laboratory staff handling the virus and infected material, clinicians and persons attending to human rabies cases, veterinarians, animal handlers and catchers, wildlife wardens, quarantine offi cers and travelers from rabies free areas to rabies endemic areas. Pre-exposure vaccination is