Clinical and epidemiologic characteristics of nodding syndrome in Mundri County, southern Sudan

Afr Health Sci. 2012 Sep;12(3):242-8. doi: 10.4314/ahs.v12i3.1.


Background: Nodding syndrome (repetitive nodding and progressive generalized seizures) is assuming epidemic proportions in South Sudan, Tanzania and Uganda.

Objective: To describe clinical and epidemiological features of nodding syndrome in southern Sudan based on preliminary investigations conducted in 2001 and 2002.

Method: Household surveys, clinical, electrophysiological (EEG) assessments, informant interviews and case-control studies were conducted in the town of Lui and the village of Amadi in southern Sudan.

Results: Nodding syndrome is characterized by involuntary repetitive nodding of the head, progressing to generalized seizures; mental and physical deterioration. The EEGs were consistent with progressive epileptic encephalopathy. Prevalence of Nodding syndrome in Lui and Amadi was 2.3% and 6.7% respectively. All case control studies showed a positive association between cases and Onchocerca volvulus. A history of measles was negatively associated with being a case: 2/13 of cases and 11/19 of controls had had measles: odds ratio 0.13 (95% CI 0.02, 0.76). Environmental assessment did not reveal any naturally occurring or manmade neurotoxic factors to explain Nodding Syndrome, although fungal contamination of food could not be ruled out.

Conclusion: Nodding Syndrome was strongly associated with Onchocerca volvulus. There was no evidence to suggest an environmental pollutant, chemical agent, or other toxic factor.

Keywords: South Sudan; clinical; epidemiology; nodding; syndrome.

MeSH terms

  • Adolescent
  • Animals
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Disease Outbreaks*
  • Electroencephalography
  • Electrophysiology
  • Female
  • Humans
  • Male
  • Onchocerca volvulus / isolation & purification
  • Onchocerciasis / complications
  • Onchocerciasis / epidemiology
  • Prevalence
  • Risk Factors
  • Seizures / complications
  • Seizures / epidemiology*
  • Seizures / etiology
  • Sudan / epidemiology
  • Young Adult