Travellers to the distant African islands of Bijagos can look forward to finding a tropical paradise of pristine seashores and plush rainforest.
However the islands usually are not simply lovely. They’re additionally a pure laboratory, offering a singular setting through which to check cures for a few of the world’s deadliest illnesses.
A group of 18 islands and 70 islets off the coast of Guinea-Bissau, West Africa, the Bijagos are dwelling to about 30,000 individuals with their very own language and distinctive traditions.
In addition they teem with wildlife, together with the uncommon saltwater hippopotamus and big sea turtle, which thrive on this distant spot.
However these tranquil islands are dwelling to many critical diseases and circumstances. Life expectancy on Guinea-Bissau is about 60, and on the Bijagos Islands it’s considered a lot decrease.
Malaria, a extreme eye an infection referred to as trachoma, lymphatic filariasis – a continual swelling typically generally known as elephantiasis – and intestinal worms are explicit issues.
Nonetheless, the islands may maintain the key to tackling the very illnesses that blight them.
A pure laboratory
Medical researchers have been engaged on the Bijagos Islands for a number of years to see if they will do away with sure illnesses from sure islands.
The explanation that the islands work so nicely as a pure laboratory is their remoteness.
Whereas this makes some on a regular basis actions tough, it’s a useful characteristic when making an attempt to eradicate illness.
The islands’ separation by water creates a pure barrier. This permits us to check totally different illness management strategies, with out the danger of cross-contamination between the take a look at websites.
On the mainland, individuals can readily transfer out and in of trial areas, contaminating the websites and making it tough to determine trigger and impact.
An island set-up permits us to fastidiously and precisely measure the influence of any intervention made.
Whereas there are various archipelagos around the globe, few have islands shut sufficient collectively to permit us to work there, however far sufficient aside to minimise interference throughout experiments.
There are additionally few islands with this format which are dwelling to so many illnesses.
Researchers from the London College of Hygiene and Tropical Medication (LSHTM) initially targeted on trachoma, an infectious illness that turns the eyelashes inwards. Affecting 1.9 million individuals globally, it’s the world’s main explanation for preventable blindness.
Trachoma may be transmitted if contaminated palms, clothes or contaminated flies come into contact with the eyes. It’s brought on by a type of chlamydia bacterium and infrequently spreads in crowded areas with insufficient sanitation.
The illness is present in 42 international locations around the globe, and at one level, there have been some villages on the islands the place each single youngster had the illness.
Dr Anna Final from LSHTM recognized excessive threat areas for trachoma, earlier than treating total communities with antibiotics to finish the cycle of transmission.
Interior eyelid swabs, taken earlier than and after the therapy, helped the researchers to detect the illness at an early stage. They’re additionally getting used to determine which genetic kinds of an infection have been current.
This may enhance understanding of what occurs after native elimination.
If the trachoma returns, we might be able to decide from its genetic pressure whether or not it got here from an out of doors supply or re-emerged from inside that neighborhood.
The outcomes have been putting. When she first started her work, 25% of individuals on the islands had the illness. Now, solely 0.3% of individuals have it.
Not solely is that this beneath the WHO threshold for elimination, which means the illness is all however eradicated from the islands, however the strategies developed might now profit the broader world.
Attending to Bijagos
- Often attracts intrepid explorers, however not a typical vacation vacation spot
- Attending to the islands may be treacherous, significantly within the wet season, when storms can come out of nowhere and trigger giant swells
- The journey from the mainland takes a minimum of 5 hours, on a small ferry full of individuals and animals
- There are few well being centres, with the biggest on the principle island of Bubaque – medical provides are restricted
- Whereas medical professionals present one of the best care they will, remoteness and inaccessibility at instances make this tough
Trachoma shouldn’t be the one downside dealing with the individuals of the Bijagos and a number of other different illnesses on the islands at the moment are being tackled.
Our present focus is malaria. This illness is unfold when feminine mosquitoes contaminated with a parasite chew a human, resulting in preliminary signs comparable to fever and a headache earlier than rapidly changing into extra extreme. Malaria kills nearly half one million individuals worldwide annually.
Given the prevalence of malaria on the islands – with as much as one in 4 individuals contaminated – it’s unsurprising we discovered mosquitoes which are excellent at transmitting the illness.
Worryingly, we additionally discovered that some have been immune to pesticides.
This implies the most typical methods to manage malaria – mattress nets and spraying homes with pesticides – could not work, which means another technique is required.
Extra like this
A brand new drug is about to be trialled, which is transferred to the mosquito by way of the sufferer’s bloodstream when it bites.
Previous remedies have tended to focus on the malaria parasite inside the human physique. However this drug targets each the mosquito and the malaria parasite, shortening their lifespan.
On this trial, all of the islands shall be given the usual management instruments, comparable to mattress nets. Some, the “intervention” islands, may also be given the drug. Others, the “management” islands, won’t.
A staff of native islanders have been educated in medical expertise, comparable to taking blood samples and screening them for malaria.
They’ve additionally discovered the best way to accumulate and determine mosquitoes, with the assistance of Ba, one in every of our area staff hoping to develop into the primary entomologist, or insect specialist, on the islands.
Seeking to the longer term
Whether or not this drug will do away with malaria on the islands as soon as and for all stays to be seen.
Both method, the teachings learnt from our research are more likely to have an effect far past the distant Bijagos Islands.
Each examine helps us to be taught concerning the illness itself and the way it’s transmitted, which shapes future analysis.
On the islands, this may be finished extra rapidly, with better management and accuracy. We will see what the results are in an outlined space, reaching a complete inhabitants.
The LSHTM venture will proceed on the Bijagos for a minimum of one other 5 years, and within the meantime, its findings are doubtless for use to sort out main illnesses like malaria elsewhere.
About this piece
This evaluation piece was commissioned by the BBC from an skilled working for an out of doors organisation. The 2-year examine in direction of infectious illness elimination on the Bijagos Islands was funded by UK Analysis and Innovation.
Prof James Logan is head of the Division of Illness Management on the London College of Hygiene and Tropical Medication. Observe him on Twitter at @ProfJamesLogan.
Edited by Eleanor Lawrie