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Why rabies persists, despite being easy to cure


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The disease kills an estimated 2,000 people every year, with Machakos, Makueni and Kitui having particularly high prevalence.

Sunday July 10 2016

Inadequate surveillance and testing has left Kenyans vulnerable to rabies, a disease spread by dog bites that is almost impossible to cure without immediate treatment.

Over the years, testing of animals has lagged far behind the number of bites reported, leaving Kenyans ignorant of the true risk they face from the disease.

According to the 2014 Rabies Elimination Strategy, rabies, which is estimated to kill about 2,000 people a year in Kenya, is endemic across the entire country, with Machakos, Makueni and Kitui having particularly high prevalence.

Dr Eric Osoro, from the Zoonotic Disease Unit (ZDU) told Newsplex via email that “Once the disease develops, it is nearly 100 per cent fatal. There are only two documented cases of people who survived rabies. Therefore treatment is supportive once disease develops, treating pain and hydration”.

In Kenya, both surveillance and laboratory capacity are inadequate. Since 1958, only 164 dogs are known to have been tested after biting a person in Kenya, and seven in ten of those tested positive for rabies, according to the ZDU.

Yet from 2012 to 2015, recorded animal bites in Kenya increased 26 per cent, from 146,721 in 2012 to 185,076, according to the ZDU, which collated data from over 7,000 health facilities in Kenya.

In other words, the number of bites reported in a single year was a thousand times the number of dogs which have been tested after biting a human to date.

Slowly, madness set in. His little body shook with episodes of tremors and convulsions and he attempted to bite all around him.

According to the rabies elimination strategy, dated September 2014, “The national surveillance data is unreliable, meaning that the true burden of the disease in the country or high risk areas remains undefined; making it difficult to target prevention and control measures.”

There are also laboratory shortages. “Countrywide, there are only three animal laboratories that have the capacity to confirm rabies in humans or animals. However, these laboratories often lack reagents for timely testing of specimens,” the report says, adding that “There are no public health laboratories which carry out human rabies diagnosis.”

AFRAID OF WATER

Studies shows that dogs are responsible for the vast majority of animal bites in Kenya. A 2016 study on rabies in Laikipia County published in the Emerging Infectious Diseases Journalshowed dogs were responsible for 88 per cent of all bites, while another 2016 study at Kilifi County Hospital showed that 98 per cent of the 308 bites recorded were by dogs.

In 2014, one fifth (19.8 per cent) of all animal bite incidents happened to children under five years old. Counties with the most animal bites were Kitui (9297), Makueni (7966), Machakos (7399) and Kakamega (7563). Turkana and Kitui also recorded the most bites to children aged under 5, at  1662 and 1451 respectively.

One veterinarian’s account of a boy dying of rabies, a viral disease he always treated in animals, reads like a horror movie.

It was in 2009 in Kisumu. He got call from a mother whose little boy had been rushed to hospital after being bitten by a dog a month earlier. It may have started with an itch around the bite mark, which may have healed by the time the itching started.

Rabies is transmitted by bites from an infected dog and is incurable once signs start presenting. The victim was so afraid of water that he could not drink no matter how thirsty he was, a condition called hydrophobia.

In fact, the sight of water in a glass induced such terror in him that he grabbed his throat, almost ripping it out. His vocal cords became paralysed and later he gagged on large amounts of thick, heavy saliva.

Slowly, madness set in. His little body shook with episodes of tremors and convulsions and he attempted to bite all around him.

TIED TO THEIR BED

A book Rabid: A Cultural History of the World’s Most Diabolical Virus written by veterinarian Monica Murphy explains further. According to Murphy, had he been older, a male victim such as he would have had a sustained erection and frequent, uncontrollable ejaculations, inducing a frenzied sexual energy that may have made him attempt to rape those around him.

Then he would have lapsed into a coma, before becoming paralysed and dying. Moreover, because of the madness, rabies is often misdiagnosed as cerebral malaria.

An Oxford Medical publication, Rabies: The Facts by Colin Kaplan, states that patients in the West who get into this agitated mode are sedated until they die. But in low-resource settings such as Africa where sedatives are scarce, they are tied to their bed, leaving them to feel the virus torture their bodies until they are no more.

Rabies is not as infectious as cholera, which sends the Ministry of Health scrambling, but it impacts on the health of Kenyans, and perhaps claims more lives than previously thought. To save a person who has been bitten by a rabid dog, vaccines are of the essence.

Dr Osoro breaks down the regimen. There is a vaccine that is given the day one is bitten. It is free in public facilities when available, but the whole dose costs Ksh8,000 in private facilities.

Then there is a special drug called Rabies Immunoglobulin — antibodies that attack the virus at once – given within the first week of vaccination at the cost of Ksh5,000 per dose.

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A vial of vaccine used to vaccinate animals against rabies. PHOTO | COURTESY

Without it, the virus from saliva of an infected dog goes to the nerves, then the spinal cord and then the brain, from where it multiplies and spreads everywhere, including the salivary glands.

When certain parts of the brain are attacked, the patient becomes a “furious rabies” and dies a week after the signs show.

In a presentation made at the Veterinarians’ Conference in Meru earlier this year, epidemiologist Dr Thumbi Mwangi pointed to two factors behind continued spread of the disease: slow government response and people’s ignorance.

Drawing from records from the State Department of Veterinary Services (DVS) from as far back as 1912, Mr Mwangi showed that rabies has been around for a long time. The Luo in South Nyanza referred to it as “Swao”.

Rabies, despite being lethal, is actually easy to eliminate

The disease was seen in dogs and jackals after the first case was recorded in 1912, but it was only in 1928 when a woman died of it in South Nyanza. After South Nyanza, other cases were recorded in Laikipia and Wajir and by 1931, Western province had experienced cases of rabies.

In 1950, the government imported a vaccine from Algiers and engaged in a rigorous vaccination exercise. However, between 1951 and the 1960s, rabies moved to Rift Valley and Central, prompting the government to adopt a policy on compulsory annual vaccination of dogs, house-to house-searches and shooting of stray dogs.

The move to shoot stray dogs has been termed by many vets as “impractical” but it may have worked because by 1974, rabies was eliminated except for a few sylvatic cases—cases of animals living in the wild—  in Machakos and Kitui.

As at 2015, of the 4,466 cases of canines biting each other that have been reported from 1958, 51 per cent or 2265 tested positive for rabies, while of the 164 cases of dogs biting human beings that were reported, 114 (69.5 per cent) tested positive for rabies.

In Kenya, as in the rest of Africa, the manner in which people relate with dogs makes this disease very hard to eliminate.

FONDNESS FOR PUPPIES

Commenting in an article in the New York Times on rabid dogs in India, John Bradshaw –Director of the Anthrozoology Institute at the University of Bristol in Britain, said that dogs started out as scavengers and evolved to hanging around people, rather than being useful to them.

While this scavenger relationship has largely dissolved in the developed world, it remains dominant in Africa. Take 9-year-old Joshua for instance, who has been treated at Jaramogi Oginga Odinga Teaching and Referral Hospital in Kisumu.

He, and most children under 15, die the most because they are fond of puppies, according to Bradshaw. There are very many dogs, some which are stray, which survive by scavenging in the improperly managed garbage dumps in cities.

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Children with a dog. A well-known "rule of paw" holds that you can tell how old your pooch is in human terms by multiplying its age in years by seven. PHOTO | COURTESY

Dr Mwangi challenges the notion that the dogs are stray, instead terming the phenomenon as “irresponsible dog ownership”. Many dogs that roam actually have owners.

Rabies, despite being lethal, is actually easy to eliminate, according to Dr Mwangi. He explains that doctors use the basic reproductive number of a disease, or the R naught (R0), to describe how many people one sick individual is capable of infecting.

When a disease has a low R0 – such as 1.2 for rabies, meaning one dog can only infect a maximum of two others — it is easier to eliminate. The opposite is true for infectious diseases such as measles, which have reproductive numbers ranging from 12 to 18.

Rabies would only need a vaccination coverage of about 70 per cent of the dogs annually for three years, as opposed to a coverage of 99.9 per cent for measles. The rabies virus would be denied a host to thrive and would then die naturally. Animal experts estimate that it may only take five years to eliminate rabies.