Operating as a ‘One Health’ Consortium in Sierra Leone

The Dynamic Drivers of Disease in Africa Consortium is focused on  animal diseases which can be passed on to humans, known as zoonoses, in Africa.   These are an important issue for poverty and public health because many emerging  infectious diseases are zoonotic and they have a big impact poor people’s lives  and livelihoods.  As this is a complex issue our consortium involves many  different types of researchers including social science, environmental science,  veterinary experts, epidemiology, ecology and much more, really a ‘One Health’  consortium.

Recently, the Sierra Leone team conducted some research  piloting and planning.   There has been a journey to reach the point where  different disciplines were able to meet and work together to pilot different  methods.  This trip allowed us some innovative opportunities to conduct  multidisciplinary work and triangulate information found from different  methods.

Lassa fever is the disease we are studying in Sierra Leone and  symptoms include intermittent fever, headache, malaise and weakness. It is a  serious disease and death can occur 10-14 days after onset of symptoms, so it is  important to get to hospital quickly.  We were lucky enough to be shown around  the Lassa fever ward in Kenema Government Hospital, which is solely for people  suffering from this disease and is the only hospital in the area equipped to  deal with these cases and all other hospitals refer patients there.  This helped  to give us a clear understanding of the work they do and how cases are handled.

We visited two of the research villages and  everywhere we went we received a warm welcome and the people living in the  villagers willingly and enthusiastically gave us their time and knowledge on the  issue of Lassa fever.  In each village we started with a village meeting  explaining why we were visiting and what we wanted to do.

In the first village we  started with participatory landscape mapping, which involves the villagers  drawing out their landscape, including crops, seasonal movements and reasons for  different activities.  We then moved on to the village epidemiological map which  was a map of just the village area, showing which families live in different  areas of the village, rodent movements, where possible risk areas for rodents  were (for example, toilets, garbage areas, wells) and finally we asked where  people had had fevers and the effects of these to see the patterns of  disease.

We also conducted a rodent and fever matrix.  This was to see  the different types of rodents in the villages and the information the villagers  had about them.  No rats were identified with disease.  We also asked them to  identify the different types of fever people experienced.  The villagers  identified mild, medium and severe fevers and favoured native herbs for  treatment.  We are so interested in rodents because disease transmission is  through a specific rodent species, so the prevalence of the virus is presumed to  reflect the abundance of these.

In the second village we started with a  focus group discussion based around questions we had from information that had  been brought up in the previous village.  The villagers in this area had  benefitted from visits by the Lassa fever outreach team and knew more about  fever and that rats carried disease.

This was a great and useful  discussion which provided us with rich information.  We then went on a transect  walk.  This is a walk through the village where we were accompanied by a small  group of villagers through the landscape. We visited different land and  ecosystem types (as marked on participatory maps), and used this as an  opportunity for ‘on the spot’ conversations about where people see rodents, and  the activities that are carried out in different places at particular times of  year.

Information from both villages came together to make a picture, for  example the village epidemiological map done in the first village showed  schoolboys to be a risk group and the villagers in the second villagers talked  of boys hunting cats and rats, giving one possible explanation for this and some  further areas to discuss.

Multidisciplinary  working
The Sierra Leone team has specialists in social science,  environmental science and medicine, ecology and epidemiology.  This is necessary  because the disease is expected to increase due to climate and land use changes  as well as improved monitoring of animal populations and pathogen screening.

All three teams will undertake research at the same time, gathering  information on the same villagers, land and houses. The time points are based on  key moments in the farming and land use calendar, annual climate/rainfall  cycles, and likely important time points for rodent population dynamics, and  therefore possible variations in Lassa transmission dynamics.  Working together  in this way will ensure that data is comparable and also allow teams to interact  and learn from each other.

Examples of how the teams will work together  include the environmental science and epidemiological team sharing information  so decisions on where to place rat traps can be based on the land use  information gathered.  Additionally, the seasonal movements of men and women  gained from the participatory mapping can be compared with the epidemiological  data on prevalence of disease.  This can be triangulated with fevers identified  in the participatory work as well as looking at the village made epidemiological  map and comparing it to the blood sample data.  Another example is that the  village epidemiological map (showing which people in which places have been sick  and if this is where rats have been seen as well as showing their proximity to  garbage, toilets, kitchens) can be  triangulated with the process based  modelling of who is most likely to get the disease. So, after a busy week of  planning, piloting and sharing ideas between disciplines everyone is now excited  to begin the next stage of the work!

by Catherine Holley, Research Officer, Dynamic Drivers of Disease in Africa and HEART Research Officer
Images: ‘Participatory mapping’  and ‘Transect walk’ . Credit: Catherine Holley.

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