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The battle to heal South Sudan's enigmatic neurological disease.
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The battle to heal South Sudan’s enigmatic neurological disease.


The other kids become scared and back away when Tabo begins to convulse. Before falling to the ground and losing consciousness, the 17-year-old Tabo takes a deep and guttural breath, her body trembling violently. Penina Monyo Gulu Biro, Tabo’s mother, carefully supports her daughter during the seizure.

After a minute or two, Tabo (shown in the image) sits back up with tears streaming down her face. Biro explains that she cries because she is upset about her current state.

In 2016, Tabo received a diagnosis of nodding syndrome, a neurological condition that had previously killed her younger sister, Nyibili.

Nodding syndrome was initially observed in Tanzania during the 1960s, followed by documented cases in South Sudan during the 1990s and in Uganda in 2007. In recent years, instances of the syndrome have also been reported in the Democratic Republic of the Congo, Central African Republic, and Cameroon. Dr. Gasim Abd-Elfarag, a specialist in this disease and leader of the charitable organization Access for Humanity in South Sudan, provided this information.

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However, the state of Western Equatoria in South Sudan, specifically Mvolo where Tabo resides, has the greatest occurrence of nodding syndrome globally. Amref Health Africa, the aid organization responsible for addressing the issue in the country, reports that over 6,000 cases have been documented at healthcare facilities in four out of the 10 counties in the state.

Amref joined the Nodding Syndrome Alliance (NSA) in 2019, a collaboration between aid organizations and universities. They work together to conduct research and operate specialized clinics in Maridi, Mundri West, and Mundri East counties, which are located to the south of Mvolo.

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There is no specialist clinic in Mvolo county, although the area is a hotspot of the disease, with 3,000 cases, according to Lexon Bira, a local coordinator for the Relief and Rehabilitation Commission, a government-run humanitarian agency.

The rural areas lack the necessary means to obtain the necessary medications for treating epilepsy symptoms.

The cause of nodding syndrome remains a mystery and a cure for this disease, which impacts children three years old and older, has not yet been discovered. The disorder persists into adulthood and is initiated by exposure to food and colder temperatures, resulting in episodes of head-nodding.

If epilepsy medications are not taken, the illness may worsen, leading to seizures that can result in accidents and possibly death. Prolonged effects can also include harm to the brain, hindered growth, and cognitive impairment.

Children suffering from nodding syndrome often experience social isolation due to being excluded from group gatherings. According to Sophia Mohammed, the South Sudan director for the NGO organization Light for the World, which advocates for disabled individuals and promotes proper eye health, these children face various forms of stigma as a result of a lack of awareness and understanding of the condition, its origins, and its mode of transmission.

She mentions that they frequently do not dine with others. Usually, they are not allowed to attend school, and those who do are often required to sit apart from the other students.


In 2019, the daughter of Lilian Sebit Doro, named Grace, passed away. Lilian believes that Grace’s death was caused by a combination of malaria and chest pain, as her body was already weakened by nodding syndrome. Unfortunately, two out of her three surviving children also suffer from the same illness.

Lilian shares a room with her 25-year-old daughter, Roda Taban, who can have as many as 12 attacks in one night. This is done to ensure that Roda’s convulsions do not accidentally harm Lilian’s baby.

Lilian’s son, who is 30 years old, experiences frequent episodes of blindness and is almost completely blind due to onchocerciasis. This ailment, also referred to as river blindness, is caused by a parasitic worm that is spread through the bite of an infected black fly.

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Lilian, who had been working as a cook for an international aid organization in Mvolo until it closed in 2022, was unable to afford medication for her epilepsy. She expresses uncertainty about the cause of her illness, speculating that it could be related to the black fly or the belief that nodding syndrome and epilepsy are a result of sharing food with a person who has not completed traditional cleansing rituals after killing a relative.

Scientists have discovered a connection between nodding syndrome, being bitten by black-flies, and contracting onchocerciasis. The black-fly population thrives in rivers with high water speed, like the Mvolo River.

Dr. Stephen Jada, a medical professional and researcher at Amref Health Africa, noted that areas with a high prevalence of onchocerciasis and close proximity to rivers have a higher incidence of epilepsy and nodding syndrome.

The number of cases decreases as you move away from the river. In villages without a river and without black-fly bites, incidences of nodding syndrome are few or nonexistent.

Nodding syndrome is likely to be a form of “onchocerciasis-associated epilepsy”, says Jada, although he adds: “We don’t know how onchocerciasis could cause the disease.

Efforts have been conducted to determine if the parasites are able to infiltrate the brain or if they produce a harmful substance that affects it, with no success,” he states. “This matter is still being investigated.”

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There have been various new hypotheses put forth to elucidate the increase in occurrences of nodding syndrome in the area. The potential reasons that have been explored include contaminated food assistance, possible utilization of chemical weapons during the civil war, and inadequate nutrition. However, according to Abd-Elfarag, there have been no definitive findings.

“It remains an enigmatic illness,” he shares. “We’re still unable to piece together the puzzle and decipher its root cause.”


Scientists have shifted their focus towards intervention studies focused on the black fly. These interventions involve clearing areas where the fly breeds and administering medication to treat onchocerciasis, which is now done twice a year by health officials. These efforts were previously interrupted by the civil war and subsequent instability after South Sudan’s independence 13 years ago.

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In the northern region of Uganda and the town of Maridi in South Sudan’s Western Equatoria, similar efforts have proven effective in reducing the impact of nodding syndrome. Eliminating both the black fly and onchocerciasis has resulted in a decrease in new cases of the disease.

Last year, a comparable method was implemented in Mvolo. At the Mvolo River, volunteers spend whole days capturing black flies and storing them in tubes, recording the quantity collected per hour. These samples are later transported to the capital city, Juba, and as of this May, to the University of Antwerp for further examination in order to determine the proportion of black flies infected with the parasite that causes river blindness.


In the town of Mundri, located 60 miles (100km) south of Mvolo, NSA’s specialized clinic has treated 1,500 patients since its establishment in 2020. By providing free medication for epilepsy, the clinic has successfully decreased the occurrence of seizures and head-nodding episodes among patients.

Joseph Yoto, the nurse at the clinic, states that 25 deaths have been documented thus far. However, the majority of those affected have experienced improvements in their lives, as they are now able to return to school or maintain employment.

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At Mundri Adventist Primary School, out of the 650 students, only five are impacted by nodding syndrome. According to Rebecca Aunty Ezbon, an education officer at the Sudan Evangelical Mission responsible for training teachers on how to care for students with this condition, there are likely more affected individuals in the community. However, parents are hesitant to enroll them in school.

Christine Tina Lukowe is a teacher who shares her thoughts about having a particular belief that if she were to touch a student who was having a seizure, the nodding would be passed on to her.

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She discovered that the illness was not easily transmitted and received guidance on the most effective way to handle epileptic seizures. She observed progress in patients who took medication supplied by the clinic and has grown confident in the capabilities of her students who have the disorder.

She explains, “A few of them enjoy creating music using old-fashioned instruments, while others prefer participating in English debates.” She emphasizes the importance of discovering where they feel the most at ease to fully express themselves and succeed in their academic pursuits.

Nineteen-year-old Negend Bouda was on the verge of quitting school due to fear and embarrassment after having a seizure in her classroom. However, her teacher persuaded her to come back and also addressed the issue with the other students.

Lukowe states that they made sure to inform others that they should not avoid or fear the person affected by the disease, as it cannot be contracted through mere association. This message was conveyed successfully and the person affected was able to take her exams. She is currently in good health and adhering to her prescribed medication.

In December 2023, Bouda passed her primary leaving certificate with flying colors. She fondly refers to her teacher as her closest confidant and ally.

She expresses her desire to pursue higher education so that she can one day become a doctor and assist those affected by nodding syndrome, as well as individuals who are visually impaired or have disabilities. She hopes to empower them to return to school, improve their physical strength, and lead fulfilling lives without fearing discrimination.

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Source: theguardian.com