Pemba Public Engagement
Working on telling the story of rabies elimination on Pemba.
Rabies is a deadly infectious disease that causes an estimated 60,000 human deaths a year, primarily in low and middle income countries. The vast majority of the deaths are caused by canine rabies, or rabies transmitted through bites from infected domestic dogs[a], and all of these deaths are preventable!
Timely post-exposure vaccination for people is highly effective at preventing rabies deaths.
And mass vaccination of the domestic dog population has been successful at controlling, and even eliminating, canine rabies in many countries.
Given that we have the tools to end deaths due to canine rabies, the global health community has set a goal to achieve zero deaths due to canine rabies by 2030[b].
This is the story of such an elimination effort on Pemba Island off the coast of Tanzania. While many have heard of the island of Unguja (better known as Zanzibar) as a vacation destination for wealthy foreign travelers, Pemba is a lesser known, but no less beautiful island community of about 400,000 people over 400 square miles people[c][d].
It may seem like a small place to start, but the saga of rabies elimination on Pemba exemplifies many of the challenges and hard-learned lessons that apply across a much broader range of settings, and even other infectious diseases.
The first recorded case of rabies occurred in 1997, but the disease has likely been brought on to the island periodically throughout history, with the occasional fishermen bringing an exposed dog from the mainland. In recent decades, suspected cases of human rabies deaths have been recorded every year or so. No mass dog vaccination campaigns were carried out on the island of Pemba until 2010 when World Animal Protection (formerly WSPA) ran a small campaign followed by a coordinated, government-led WHO rabies elimination and demonstration program in southeastern Tanzania that included Pemba Island between 2011 - 2016.
This is where we pick up the story with PhD student Kennedy Lushasi, a rabies researcher at the University of Glasgow who has been tracking rabies cases across Pemba for the past 7 years.
After a long bus, boat, and dalla dalla[f] ride (the little buses that transport people between the different towns on Pemba), we find Kennedy in ChakeChake, the bustling capital of the island.
He meets up with Veterinary officer, Dr Hemed at the District Livestock office.Together, they take a motorbike to theChakeChake Regional Referral Hospital and meet the local clinician, Dr X, who provides them with a list of patients who sought treatment at the hospital after being bitten by domestic dogs. Kennedy’s goal is to try and visit each of these patients, to interview them about the circumstances surrounding the bite, and to pull together the clues that would suggest that the biting dog was rabid.
What are these clues? How can we tell a rabid dog from any other? Kennedy and Dr. Hemed are headed to Selem where a cluster of animal bites has been reported to the clinic. They first visit with Saanane, who tells them that a few months ago one of his dogs, Killa began behaving strangely. He started moving strangely, stopped eating and drinking, and he bit Mr. Saanane’s other three dogs Polisi, Hatari, and Simba. Killa died a few days later.
These are some of the classic symptoms of a rabid animal. The virus causes severe neurological disease and eventually leads to death in people and animals. The infection in the brain also causes the very behavior that transmits the infection onwards: bites. These indicators make it possible to diagnose rabies based on these clinical signs and outcomes, and to link cases by following the biting behavior of animals, or contact tracing.
In other cases, Kennedy follows up with a bite patient to much more mundane circumstances. [g]When he talks with Lady M, she tells him that she was bitten by her neighbor’s guard dog a few months ago, when coming through his backyard. The owner of the dog tied up the dog after the bite, and it is alive and healthy to this date. In these cases, we can rule out rabies based on the fact that the dog was still alive many months after the bite.
While talking to Lady M, Kennedy gets a call from a livestock field officer, the officials responsible for animal health on the island. A dog has bitten multiple people and animals and been killed in Mapofu. The officer has taken a brain sample from the dog for further confirmation. He used a rapid diagnostic kit in the field to get a preliminary confirmation: the dog tested positive for rabies. This goes a step beyond following the clinical signs, with a diagnostic confirmation, we can move from a probable rabies case diagnosis to a confirmed diagnosis. Kennedy and the officer will prep the sample and send it for further diagnostic testing on mainland Tanzania, and will take it even a step further, sequencing the virus.
Over the past 10 years Kennedy and the team of folks on Pemba have worked to trace 300 animal bites. 207 of these were probable rabies cases through clinical diagnosis, 38 of which were confirmed through a rapid diagnostic test, and 22 were further sequenced. Through their work, we can trace the story of elimination of rabies on Pemba in terms of the epidemiology and biology of the disease, but also the impacts it has on people’s lives.
Section on burden
Section on pep
Section on dog vaccination
Section on surveillance
Conclusion
Methods