Pr. Louis-Albert Tchuem Tchuenté University of Yaoundé, Cameroon


Pr. Louis-Albert Tchuem Tchuenté

University of Yaoundé, Centre for Schistosomiasis & Parasitology

Cameroon

Interview by Kamran Rafiq (ISNTD) April 2016

Pr. Louis-Albert Tchuem Tchuenté is Professor of Parasitology at the University of Yaoundé, director & founder of Cameroon’s Centre for Schistosomiasis & Parasitology and Coordinator of the National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis in Cameroon. With 30 years of experience in numerous aspects of management, research and control of schistosomiasis, soil-transmitted helminthiasis and other neglected tropical diseases (NTDs), Pr. Tchuenté speaks here about the main strategies and successes in the control of NTDs, building high political commitments, as well as the challenges remaining ahead for the NTD community.

What have been some of the main public health challenges in Cameroon in recent times and what have been the strategies put in place to address these?

One of the main public health challenges in Cameroon in recent times have been the control of neglected tropical diseases (NTDs). These diseases affect the lives of millions of impoverished populations, and the priority NTDs in Cameroon are schistosomiasis, soil-transmitted helminthiasis, onchocerciasis, lymphatic filariasis, trachoma, Guinea worm, human African trypanosomiasis, Buruli ulcer, leprosy, leishmaniasis and yaws. These diseases are widely distributed and co-endemic in many parts of the country. To overcome these diseases, six specific control programmes have been created between 1998 and 2010. In 2012, a national Master Plan 2012-2016 for the control/elimination of NTDs and the strategies are centered around three drug distribution channels: (i) school-based deworming for schistosomiasis and STH; (ii) community-based interventions for onchocerciasis, LF and trachoma; and (iii) vaccination campaign for the deworming of pre-school aged children (< 5 years).

There have been tremendous efforts across Cameroon but also a number of African countries to comprehensively map Neglected Tropical Diseases. How successful has mapping been in Cameroon and has this translated in more targeted research and control programmes? What have been some of the main chal-lenges nationally as well as regionally in coordinating mapping efforts?

Knowing the distribution of a disease is a prerequisite to properly defining the areas and strategies for control interventions. Cameroon has completed the mapping of the five NTDs targeted by preventive chemotherapy (schistosomiasis, STH, onchocerciasis, LF, trachoma) by 2012, and this was a great achievement and a crucial step to scale- up interventions in all areas of need of mass drug administration in order to achieve targets for control and elimination. The mapping status is very different between health districts in Cameroon and between African countries. Several challenges arose in coordinating efforts within the country and across the continent. These include: coordination of partners and resources for mapping (there are several partners supporting mapping activities in different countries and each partner has an individual vision, interest and mapping approach); harmonisation of tools and method/protocol; and insufficient government leadership (in some countries).

You are extremely active in terms of research on polyparasitism and coinfection. What have been your main findings looking at Cameroon and what implications does this have for control strategies. Is there, globally, a sufficient understanding of coinfection & comorbidity when it comes to NTDs?

My work showed that polyparasitism is frequent in many parts of Cameroon where most children are co-infected by at least two species of parasite. It is likely that people harbouring multiple species infections are subject to heavy infections and will have exacerbated morbidity. Knowing the type of co-infections is essential to developing adequate drug co-administrations. Interestingly, my work demonstrated that interspecific interactions in schistosomes have significant impacts on parasite epidemiology, species location in humans, genetic heterogeneity, transmission dynamics of schistosomiasis and control strategies. My work on human schistosome interactions showed that the presence of Schistosoma haematobium or S. mansoni prevents that of S. intercalatum through interspecific competition processes, and suggested that S. intercalatum was an endangered species in Cameroon.

In your opinion, what are some of the most urgent research priorities for the control of NTDs or schistosomiasis in particular?

Taking into account the different components of NTD transmission – and schistosomiasis in particular – and the control/elimination interventions and challenges, the research priorities to optimize control strategies can be grouped in 5 major core themes:

(1) Intervention

  • Optimize treatment/control strategies according to different transmission dynamics.

  • Reaching unenrolled and pre- school-age children, and high-risk adults with preventive chemotherapy.

  • Monitor drug efficacy an