As countries get closer to eliminating one or more neglected tropical diseases (NTDs), some communities or population groups are at risk of being left behind.

As part of our research in Cameroon, we have been exploring new ways to find and treat semi-nomadic people for river blindness. We’ve used local guides, mobile apps and satellite imagery in order to find and include these remote communities.

In this blog we’ll be discussing what we’ve learned, and how our findings could be used by other NTD programmes working with nomadic, semi-nomadic and other hard-to-reach populations around the world.

Leaving no-one behind

Sightsavers and our partners in Cameroon have been working for many years to eliminate river blindness – a debilitating disease, which if left untreated, can cause irreversible blindness.

Our main strategy for tackling the disease has been to distribute ivermectin through a series of mass drug administration (MDA) campaigns. However, we noticed in Cameroon that semi-nomadic minority people in the Massangam health district of the West Region were missing out on treatment.

It’s essential these communities receive the medicine because their camps are usually set up near riverbanks, which puts them at higher risk of being bitten by the blackflies that carry river blindness.

Nomadic communities could also have a role in perpetuating the transmission of river blindness. This is because if they are not treated, they could represent a roaming reservoir of infection that could make it more difficult to eliminate the disease, or cause recrudescence where control or elimination has been achieved.

We wanted to address these challenges, so we launched a research study that looked at how to reach and treat the semi-nomadic population in Massangam. We also measured the rate of population immigration and emigration (turnover) and established the prevalence of river blindness in the semi-nomadic communities.We decided that it would be best to visit the nomadic camps, rather than expecting semi-nomads living within the camps to travel to settled communities to receive treatment. Our approach included using semi-nomadic guides, engaging more with semi-nomadic communities, and creating materials in the local language (Fulfulde).

We trained semi-nomadic drug distributors, who worked alongside drug distributors from settled communities to provide medication to the semi-nomadic groups.

We also used satellite imagery and Geographic Information System (GIS) tools to help us locate the camps, and find our way through rough terrain and thick vegetation in order to reach them. 

What we’ve learned

  1. The semi-nomadic population is very young and dynamic, with a turnover rate of 47% over one year in Massangam.
  2. There is a high prevalence of river blindness (16.5%) and low MDA participation rate among semi-nomads in Massangam, compared to the settled population.
  3. Our efforts to reach nomadic camps were successful. By carrying out engagement and sensitisation that was specific to the semi-nomadic communities, we were able to increase participation compared to previous programmes.
  4. We used an alternative treatment strategy, which included testing and treating semi-nomadic communities with doxycycline. We found this to be an impactful approach; in one year, the strategy reduced the prevalence and intensity of infection significantly. We also found that it was practical and feasible to combine this ‘test and treat’ strategy with ivermectin MDA, and that this boosted MDA coverage.
  5. We worked with local guides who had extensive knowledge of the nomadic camps. We also used satellite imagery and GIS tools to build on this knowledge. These tools helped us not only to validate what we had learned from the guides, but also to identify previously unknown and unreached nomadic camps.

In future, we will be refining our own methods for reaching nomadic communities, including the use of GIS tools, satellite imagery and other innovative techniques.

This approach will be needed more than ever in the time of disease elimination, when the challenge of reaching and including mobile and remote groups – such as the Maasai people in Tanzania and Kenya, the Fulani in Nigeria and Cameroon, or the Karamojong in Uganda – requires an urgent solution.

We’re also calling for national NTD elimination programmes to take greater steps to include these communities, and we will be working with programme teams and donors to achieve these important developments.

We’ve learnt some key lessons about hard-to-reach populations, and we know that by modifying approaches to identifying excluded groups, and finding strategies for testing and treating them, we can make a significant difference.

If you’d like to find out more about our research, you can download the full report from the study as well as a research summary. You can also find more information about the study on our website.

This work received financial support from the Coalition for Operational Research on Neglected Tropical Diseases, which is funded at The Task Force for Global Health primarily by the Bill & Melinda Gates Foundation, by the United States Agency for International Development through its Neglected Tropical Diseases Program, and with UK aid from the British people.

Photo credit: Sightsavers.



Sangou, a community volunteer from a settled community, gives treatment to Aicha after screening has taken place in camp Mohamadou, Njinjouet.

Sangou, a community volunteer from a settled community, gives treatment to Aicha after screening has taken place in camp Mohamadou, Njinjouet.