Rabies: Zero by 30, World Rabies Day 2017: 28 September is World Rabies Day
Rabies: Zero by 30, World Rabies Day 2017: It is celebrated annually to raise awareness about rabies prevention and to highlight progress in defeating this horrifying disease.
28 September also marks the anniversary of Louis Pasteur’s death, the French chemist and microbiologist, who developed the first rabies vaccine.
Rabies: Zero by 30 At the global conference on rabies elimination in 2015, a common goal of zero human deaths from canine rabies by 2030 was agreed by the World Health Organization, World Organisation for Animal Health, UN Food and Agriculture Organization and GARC. In support of this goal, the 2017 World Rabies Day theme is Rabies: Zero by 30. https://rabiesalliance.org/world-rabies-day
Today, safe and efficacious animal and human vaccines are among the important tools that exist to eliminate human deaths from rabies while awareness is the key driver for success of communities to engage in effective rabies prevention.
- Rabies is a vaccine-preventable viral disease which occurs in more than 150 countries and territories.
- Dogs are the main source of human rabies deaths, contributing up to 99% of all rabies transmissions to humans.
- Rabies elimination is feasible through vaccination of dogs and prevention of dog bites.
- Infection causes tens of thousands of deaths every year, mainly in Asia and Africa.
- 40% of people bitten by suspect rabid animals are children under 15 years of age.
- Immediate, thorough wound washing with soap and water after contact with a suspect rabid animal is crucial and can save lives.
Rabies is an infectious viral disease that is almost always fatal following the onset of clinical symptoms. In up to 99% of cases, domestic dogs are responsible for rabies virus transmission to humans. Yet, rabies can affect both domestic and wild animals. It is spread to people through bites or scratches, usually via saliva.
Rabies is present on all continents, except Antarctica, with over 95% of human deaths occurring in the Asia and Africa regions.
Rabies is one of the neglected tropical diseases that predominantly affects poor and vulnerable populations who live in remote rural locations. Although effective human vaccines and immunoglobulins exist for rabies, they are not readily available or accessible to those in need. Globally, rabies deaths are rarely reported and children between the ages of 5–14 years are frequent victims. Treating a rabies exposure, where the average cost of rabies post-exposure prophylaxis (PEP) is US$ 40 in Africa, and US$ 49 in Asia, can be a catastrophic financial burden on affected families whose average daily income is around US$ 1–2 per person.
Every year, more than 15 million people worldwide receive a post-bite vaccination. This is estimated to prevent hundreds of thousands of rabies deaths annually.
Eliminating rabies in dogs
Rabies is a vaccine-preventable disease. Vaccinating dogs is the most cost-effective strategy for preventing rabies in people. Dog vaccination reduces deaths attributable to rabies and the need for PEP as a part of dog bite patient care.
Awareness on rabies and preventing dog bites
Education on dog behaviour and bite prevention for both children and adults is an essential extension of a rabies vaccination programme and can decrease both the incidence of human rabies and the financial burden of treating dog bites. Increasing awareness of rabies prevention and control in communities includes education and information on responsible pet ownership, how to prevent dog bites, and immediate care measures after a bite. Engagement and ownership of the programme at the community level increases reach and uptake of key messages.
Preventive immunization in people
Human rabies vaccines exist for pre-exposure immunization. These are recommended for people in certain high-risk occupations such as laboratory workers handling live rabies and rabies-related (lyssavirus) viruses; and people (such as animal disease control staff and wildlife rangers) whose professional or personal activities might bring them into direct contact with bats, carnivores, or other mammals that may be infected.
Pre-exposure immunization is also recommended for travellers to rabies-affected, remote areas who plan to spend a lot of time outdoors involved in activities such as caving or mountain-climbing. Expatriates and long-term travellers to areas with a high rabies exposure risk should be immunized if local access to rabies biologics is limited. Finally, immunization should also be considered for children living in, or visiting, remote, high-risk areas. As they play with animals, they may receive more severe bites, or may not report bites.
The incubation period for rabies is typically 1–3 months but may vary from 1 week to 1 year, dependent upon factors such as the location of virus entry and viral load. Initial symptoms of rabies include a fever with pain and unusual or unexplained tingling, pricking, or burning sensation (paraesthesia) at the wound site. As the virus spreads to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops.
There are two forms of the disease:
- People with furious rabies exhibit signs of hyperactivity, excitable behaviour, hydrophobia (fear of water) and sometimes aerophobia (fear of drafts or of fresh air). Death occurs after a few days due to cardio-respiratory arrest.
- Paralytic rabies accounts for about 30% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.
Current diagnostic tools are not suitable for detecting rabies infection before the onset of clinical disease, and unless the rabies-specific signs of hydrophobia or aerophobia are present, clinical diagnosis may be difficult. Human rabies can be confirmed intra-vitam and post mortem by various diagnostic techniques that detect whole viruses, viral antigens, or nucleic acids in infected tissues (brain, skin, urine, or saliva).
People are usually infected following a deep bite or scratch from an animal with rabies, and transmission to humans by rabid dogs accounts for 99% of cases. Africa and Asia have the highest rabies burden in humans and account for 95% of rabies deaths, worldwide.
In the Americas, bats are now the major source of human rabies deaths as dog-mediated transmission has mostly been broken in this region. Bat rabies is also an emerging public health threat in Australia and Western Europe. Human deaths following exposure to foxes, raccoons, skunks, jackals, mongooses and other wild carnivore host species are very rare, and bites from rodents are not known to transmit rabies.
Transmission can also occur when infectious material – usually saliva – comes into direct contact with human mucosa or fresh skin wounds. Human-to-human transmission through bites is theoretically possible but has never been confirmed.
Contraction of rabies through inhalation of virus-containing aerosols or through transplantation of infected organs is rare. Contracting rabies through consumption of raw meat or animal-derived tissue has never been confirmed in humans.
Post-exposure prophylaxis (PEP)
Post-exposure prophylaxis (PEP) is the immediate treatment of a bite victim after rabies exposure. This prevents virus entry into the central nervous system, which results in imminent death. PEP consists of:
- extensive washing and local treatment of the wound as soon as possible after exposure;
- a course of potent and effective rabies vaccine that meets WHO standards; and
- the administration of rabies immunoglobulin (RIG), if indicated.
Effective treatment soon after exposure to rabies can prevent the onset of symptoms and death.
Extensive wound washing
This involves first-aid of the wound that includes immediate and thorough flushing and washing of the wound for a minimum of 15 minutes with soap and water, detergent, povidone iodine or other substances that kill the rabies virus.
Depending on the severity of the contact with the suspected rabid animal, administration of PEP is recommended as follows (see table):
|Table: Categories of contact and recommended post-exposure prophylaxis (PEP)
|Categories of contact with suspect rabid animal
|Post-exposure prophylaxis measures
|Category I – touching or feeding animals, licks on intact skin
|Category II – nibbling of uncovered skin, minor scratches or abrasions without bleeding
|Immediate vaccination and local treatment of the wound
|Category III – single or multiple transdermal bites or scratches, licks on broken skin; contamination of mucous membrane with saliva from licks, contacts with bats.
|Immediate vaccination and administration of rabies immunoglobulin; local treatment of the wound
All category II and III exposures assessed as carrying a risk of developing rabies require PEP. This risk is increased if:
- the biting mammal is a known rabies reservoir or vector species
- the exposure occurs in a geographical area where rabies is still present
- the animal looks sick or displays abnormal behaviour
- a wound or mucous membrane was contaminated by the animal’s saliva
- the bite was unprovoked
- the animal has not been vaccinated.
The vaccination status of the suspect animal should not be the deciding factor when considering to initiate PEP or not when the vaccination status of the animal is questionable. This can be the case if dog vaccination programmes are not being sufficiently regulated or followed out of lack of resources or low priority.
WHO continues to promote human rabies prevention through the elimination of rabies in dogs, dog bite prevention strategies, and more widespread use of the intradermal route for PEP which reduces volume and therefore the cost of cell-cultured vaccine by 60% to 80%.
Integrated bite case management
If possible, the veterinary services should be alerted, the biting animal identified and quarantined for observation (for healthy dogs and cats). Alternatively, the animal may be euthanized for immediate laboratory examination. Prophylaxis must be continued during the 10-day observation period or while awaiting laboratory results. Treatment may be discontinued if the animal is proven to be free of rabies. If a suspect animal cannot be captured and tested, then a full course of prophylaxis should be completed.