Nodding syndrome in Mundri county, South Sudan: Environmental, nutritional and infectious factors

In June 2020, a door-to-door household survey was conducted in Mvolo County, an onchocerciasis endemic area in South Sudan. A total of 2,357 households containing 15,699 individuals agreed to participate in the study. Of these, 5,046 (32.1%, 95%CI: 31.4-32.9%) had skin itching and 445 (2.8%, 95% CI: 2.6-3.1%) were blind. An epilepsy screening questionnaire identified 813 (5.1%) persons suspected to have epilepsy. Of them, 804 (98.9%) were seen by a medical doctor and in 798 (98.1%) the diagnosis of epilepsy was confirmed. The overall epilepsy prevalence was 50.8/1000 (95% CI: 47.6-54.4/1000) and prevalence of nodding syndrome was 22.4/1000 (95% CI: 20.1-24.9/1000). Younger age, being male, skin itching, blindness and living in a village close to the Naam river were risk factors for epilepsy. The annual incidence of epilepsy was 82.8/100,000 (95% CI: 44.1-141.6/100,000). In conclusion, a high prevalence and incidence of epilepsy was observed in Mvolo, South Sudan. Strengthening the onchocerciasis elimination programme is urgently needed to prevent epilepsy in this region.

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The Role of the Maridi Dam in Causing an Onchocerciasis-Associated Epilepsy Epidemic in Maridi, South Sudan: An Epidemiological, Sociological, and Entomological Study

Pathogens ◽

10.3390/pathogens9040315 ◽

2020 ◽

Vol 9 (4) ◽

pp. 315 ◽

Cited By ~ 2

Author(s):

T. L. Lakwo ◽

S. Raimon ◽

M. Tionga ◽

J. N. Siewe Fodjo ◽

P. Alinda ◽

...

Keyword(s):

South Sudan ◽

Breeding Site ◽

Control Measures ◽

Group Discussions ◽

Breeding Sites ◽

Nodding Syndrome ◽

Number Of Children ◽

Village Elders ◽

The Village

Background: An epilepsy prevalence of 4.4% was documented in onchocerciasis-endemic villages close to the Maridi River in South Sudan. We investigated the role of the Maridi dam in causing an onchocerciasis-associated epilepsy epidemic in these villages. Methods: Affected communities were visited in November 2019 to conduct focus group discussions with village elders and assess the OV16 seroprevalence in 3- to 9-year-old children. Entomological assessments to map blackfly breeding sites and determine biting rates around the Maridi River were conducted. Historical data regarding various activities at the Maridi dam were obtained from the administrative authorities. Results: The Maridi dam was constructed in 1954–1955. Village elders reported an increasing number of children developing epilepsy, including nodding syndrome, from the early 1990s. Kazana 2 (the village closest to the dam; epilepsy prevalence 11.9%) had the highest OV16 seroprevalence: 40.0% among children 3–6 years old and 66.7% among children 7–9 years old. The Maridi dam spillway was found to be the only Simulium damnosum breeding site along the river, with biting rates reaching 202 flies/man/h. Conclusion: Onchocerciasis transmission rates are high in Maridi. Suitable breeding conditions at the Maridi dam, coupled with suboptimal onchocerciasis control measures, have probably played a major role in causing an epilepsy (including nodding syndrome) epidemic in the Maridi area.

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