SATURDAY, SEPTEMBER 24, 2016

Researchers planning a single antivenom for sub-Saharan Africa

Researchers create single antivenom for sub-Saharan Africa

Scientists at the Liverpool School of Tropical Medicine (LSTM) plan to develop a new “universal antivenom” for sub-Saharan Africa, where some of the world’s most venomous snakes reside and endanger human health.

There are 32,000 deaths each year from snakebites in sub-Saharan Africa; 96,000 people are permanently disabled due to these snakebites. A universal antivenom would be instrumental in preventing these deaths and disabilities.

Two issues currently pose problems for antivenom development.

One is the need for refrigeration. This poses a problem for the limited resources of rural and remote health clinics in sub-Saharan Africa. The scientists will add specialized molecules that should improve the stability of the antivenom when it is stored at ambient temperatures.

The second issue is the method that is used to create multispecies antivenoms. Snake venom is milked from multiple snake species. Low doses of the venom are injected into animals like sheep or horses. These injections don’t make the animals sick, but the animals’ immune response creates useful antibodies, which are them purified from the blood. These purified elements lead to the antivenom treatment.

Unfortunately this method makes weak antivenom because the animals’ immune responses make just a small quantity of antibody for each venomous species.

The LSTM researchers will use a new method, antivenomics, to try to increase the efficacy of an antivenom that will treat multiple venomous species snakes. This method will cover the most common and most venomous snakes native to sub-Saharan Africa. Researchers have compiled 21 of the most venomous species of Africa’s snakes to “milk” for the antivenom.

The Costa Rica-based team will produce the antivenom using a system that reduces the manufacturing costs and makes the treatment more affordable for remote and rural Africans.

There 450 venomous snakes in Africa. Countries like the U.K. have only one kind of venomous snake; snakebite victims in these areas can take antivenom that is specifically designed for the single snake. Unfortunately, areas with more than one kind of venomous snake create a greater challenge for researchers developing antivenom.

“There are over 20 species of deadly snakes in sub-Saharan Africa and doctors often rely on the victim’s description of the animal to help them decide which treatment to administer,” Head of LSTM’s Alistair Reid Venom Research Unit Dr. Robert Harrison said.

Because the only current alternative is multiple doses of multiple treatments, many times the antivenom treatment becomes too expensive for the typical subsistence farmers to afford. These subsistence farmers are the ones at the greatest risk for venomous snakebites.

The scientists recently received funding from the Medical Research Council to further their research.