The Taabo Health and Demographic Surveillance System (HDSS) is a research station of the Centre Suisse de Recherches Scientifiques en Côte d'Ivoire (CSRS) located in south-central Côte d'Ivoire, about 150 km northwest of Abidjan. The HDSS started its activities in early 2009 and the artificial lake of Taabo was chosen for its key eco-epidemiological feature. Since its inception, there has been a strong interest in the research and integrated control of water-associated diseases such as schistosomiasis and malaria. The Taabo HDSS has generated setting-specific data on the impact of targeted interventions against malaria, schistosomiasis, and other neglected tropical diseases. It covers a small town, 13 villages, and over 100 hamlets. By the end of 2013, with a total population of 42,480, 6707 selected households were under surveillance. Verbal autopsies had been performed to determine the causes of death.
Repeated cross-sectional epidemiological surveys on about 5-7% of the population and specifically hematological and parasitological surveys and with questionnaires were conducted. The Taabo HDSS provides a database for surveys, facilitates interdisciplinary research and surveillance, and provides a platform for the evaluation of health interventions. It continuously provides updated socio-demographic information on over 40,000 inhabitants in a predominantly rural area of the south central coast. The Taabo HDSS has an interdisciplinary team of demographers, statisticians, database managers, field investigators and data entry operators. The participation rate for routine surveillance is very high, sometimes exceeding 95%. A close link with the health system not only allows for effective interventions, but also facilitates feedback to health authorities. In addition, existing and productive partnerships grant the HDSS access to the laboratory of the public hospital in the town of Taabo, and other well-equipped laboratories such as those of the CSRS, the University Felix Houphouët-Boigny in Abidjan and the Swiss Tropical and Public Health Institute (Swiss TPH) in Basel. The Taabo HDSS can be used for the implementation of clinical trials to evaluate the efficacy and safety of antihelminthic drugs and the monitoring of the cost-effectiveness of interventions directed not only against Neglected Tropical Diseases and malaria but also for broader public health issues.
In addition, it is important to note that the Taabo HDSS remained active during the prolonged socio-political crisis that occurred in Côte d'Ivoire until 2012, which even allowed for a detailed study of the effects of this situation on the internally displaced population. The Taabo HDSS provides a unique platform for research as well as teaching and training of Masters of Science, Health Professionals and PhD. and postdoctoral fellows from diverse backgrounds, disciplines and cultures. Quality control mechanisms are in place and are being followed. Supervisors regularly monitor data obtained by field investigators. Data are entered twice by independent operators and there is a series of quality control steps to check for internal consistency. However, problems remain. First, long-term financial sustainability that will require new, ongoing research funding through competitive bidding. Second, the HDSS database is currently underutilized for specific analyses with respect to settings and comparisons with other demographic surveillance sites in the INDEPTH network.
The team also encountered some difficulties in collecting blood samples for specific research projects. Specific information campaigns have helped to overcome these difficulties. Often, some parents attribute their children's illnesses to their participation in a survey. As a result, the HDSS-under national law-had to provide free treatment at health facilities for all children who became ill after an epidemiological investigation. From the experiences and lessons learned, it is clear that regular feedback and sharing of key findings with the local population is essential. The Taabo HDSS needs a more elaborate data sharing policy and there is a desire to further expand the current network of partnerships and collaborations with different institutions and researchers. A priority identified is the collection of data using tablets rather than hard copies.
The Taabo HDSS is the first of its kind in Côte d'Ivoire and is built on three main pillars: demographic surveillance, health interventions, and evaluation and scientific research to strengthen local evidence. The Taabo HDSS is located in a diverse socio-ecological system and covers both rural and urban areas, providing a unique platform to study infectious and chronic diseases and the dynamics of nutrition and lifestyle issues. The specialty of the Taabo HDSS is the focus on neglected tropical diseases such as lymphatic filariasis, schistosomiasis, geo-helminthiasis and waterborne diseases in general.