An Interdisciplinary Study Contributing to the Identification of the Cause of Nodding Syndrome In Four Countries (Nodding)

Nodding syndrome (NS) is a severely debilitating neurological syndrome, currently affecting an increasing number of children between 5 and 15 years of age in onchocerciasis endemic areas in Africa. NS is characterized by head-nodding, often followed by other types of seizures, developmental retardation and growth faltering. In the affected regions, NS is a major public health problem associated with high morbidity and mortality, severe socio-economic consequences and social exclusion. The exact disease burden is unknown but the prevalence in certain villages in South Sudan is alarmingly high (9%). As the disease is currently incurable it is important to rapidly determine its cause and identify ways of stopping ongoing epidemics. Epidemiological data on risk factors across affected areas, however, are incomplete.
We hypothesize that blackflies (Simuliidae), the vectors transmitting Onchocerca volvulus (the cause of river blindness), also transmit a pathogen (possibly a neurotropic virus) responsible for causing NS. In an ongoing virology study, the hypothesis that viral transmission is enhanced in blackflies co-infected with microfilariae is being tested. However, detecting an unknown virus can be a lengthy procedure and even once a virus is found, ways of reducing the disease burden and stopping epidemics still have to be developed. It is therefore urgent o collect additional data on the socio-demographic and environmental circumstances in which NS epidemics occur to contribute to the development of control strategies. The present SOFI proposal aims to check the epidemiological, anthropological and eco-entomological premises of the hypothesis across 4 affected countries along the same latitude (Uganda, Tanzania, the Democratic Republic of Congo and Cameroon) and provide data for improved NS control.

Project type:PhD project