Neglected tropical diseases in Nigeria

Neglected tropical diseases are a diverse group of infectious diseases caused by various pathogens, including viruses, bacteria, parasites, fungi, and toxins. ^{[1] [2] [3]} These diseases disproportionately affect impoverished communities, particularly in tropical and subtropical regions. In Nigeria, neglected tropical diseases are a significant public health concern due to their widespread prevalence and socio economic impact.

Epidemiology

Nigeria has one of the highest burdens of neglected tropical diseases in Africa. The epidemiology of these diseases in the country is influenced by environmental conditions, poverty, inadequate healthcare infrastructure, and a high reliance on subsistence agriculture. Many neglected tropical diseases in Nigeria are vector borne, have animal reservoirs, and exhibit complex life cycles, which pose significant challenges for public health interventions. ^{[4] [5]}

List

Elephantiasis

• Lymphatic filariasis: Also known as elephantiasis, is a parasitic disease caused by worms such as Wuchereria bancrofti, Brugia malayi, and Brugia timori. It is transmitted through mosquito bites from species like Anopheles, Culex, Aedes, and Mansonia . The infection affects the lymphatic system, leading to severe swelling (lymphedema) in the limbs, genitals, and breasts. Over time, the skin thickens, and the affected areas become painful, making movement difficult. The disease can result in significant complications, including disability, secondary infections, and psychological distress. Many individuals suffering from lymphatic filariasis face social stigma due to their appearance, which can impact their mental health and quality of life. In severe cases, the condition limits mobility and daily activities, contributing to long-term physical and emotional suffering. ^{[6] [7]}

• Onchocerciasis, commonly known as river blindness, is caused by Onchocerca volvulus , a parasitic worm transmitted through the bites of infected blackflies (Simulium species). These blackflies breed in fast-flowing rivers, making communities near such areas particularly vulnerable. Once inside the human body, the worms produce microfilariae, which migrate through the skin and eyes, leading to severe health issues. The symptoms of onchocerciasis include intense itching, skin rashes, and depigmentation, often referred to as "leopard skin." Infected individuals may also develop nodules under the skin where adult worms reside. Over time, the disease can cause vision impairment, eventually leading to irreversible blindness. Beyond physical suffering, the disease creates social and economic burdens, as affected individuals may struggle with daily activities and employment. Prevention and treatment of onchocerciasis primarily involve the administration of ivermectin, which kills the microfilariae and helps control the disease's progression. Additionally, efforts to reduce the blackfly population through vector control methods, such as insecticide spraying, play a crucial role in minimizing transmission. Continuous treatment and preventive measures are essential to reducing the impact of this debilitating disease, particularly in endemic regions. ^{[8] [9]}

• Schistosomiasis, also known as bilharzia, is a parasitic disease caused by various species of Schistosoma, including S. mansoni , S. haematobium , and S. japonicum . The infection occurs when individuals come into contact with freshwater contaminated by infected snails that release parasitic larvae. Once inside the body, the parasites mature and migrate to different organs, leading to symptoms such as blood in urine (urinary schistosomiasis), diarrhea, liver damage, and in severe cases, kidney failure. If left untreated, schistosomiasis can cause serious complications, including bladder cancer, liver fibrosis, anemia, and growth retardation in children. Preventing schistosomiasis involves avoiding contact with contaminated water sources and implementing snail control measures to reduce the spread of infection. Mass drug administration with praziquantel is an effective treatment strategy to eliminate the parasites and prevent long-term complications. Public health efforts focus on improving water sanitation, educating at-risk communities, and promoting early diagnosis and treatment to minimize the disease’s impact. Through sustained preventive measures and treatment programs, schistosomiasis can be effectively controlled and its burden significantly reduced.

Ascaris_infection_in_X-ray_image-_Pica,_the_practice_of_eating_soil_(South_Africa)_(16424840111)

• Soil-transmitted helminths, including roundworms ( Ascaris lumbricoides ), hookworms ( Necator americanus , Ancylostoma duodenale ), and whipworms (Trichuris trichiura), are parasitic worms that infect humans through contaminated food, water, or direct contact with infected soil. These parasites cause significant health issues such as malnutrition, stunted growth, anemia, abdominal pain, and diarrhea. In children, chronic infections can lead to cognitive impairment and reduced school performance, further impacting their development. The transmission of these worms is primarily linked to poor sanitation and hygiene practices, making them prevalent in regions with inadequate access to clean water and proper waste disposal. Preventing soil transmitted helminth infections requires a combination of improved sanitation, hygiene education, and mass deworming programs. Promoting proper handwashing, wearing protective footwear, and ensuring access to clean water can significantly reduce infection rates. Deworming treatments, such as albendazole and mebendazole, are widely used in public health initiatives to control and eliminate infections, especially among school-aged children. Addressing these parasitic infections is crucial for improving overall health, enhancing educational outcomes, and breaking the cycle of poverty in affected communities. ^[10]

Trachoma_1

• Trachoma is an infectious eye disease caused by the bacterium Chlamydia trachomatis . It spreads through direct contact with eye discharge from infected individuals or via flies acting as vectors. The infection initially causes redness, irritation, and pus discharge in the eyes. If left untreated, repeated infections lead to trichiasis, a condition where the eyelashes turn inward and scrape against the cornea, resulting in scarring. Severe cases can cause irreversible blindness, making trachoma a leading cause of preventable blindness worldwide. Preventing and treating trachoma involves the SAFE strategy, Surgery to correct trichiasis, Antibiotics like azithromycin to eliminate the infection, Facial cleanliness to reduce transmission, and Environmental improvements such as better sanitation and reduced fly breeding. Public health initiatives targeting hygiene and access to clean water play a crucial role in reducing the disease’s prevalence. With sustained efforts, trachoma can be eliminated as a public health concern in affected regions. ^[11]

• Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by Mycobacterium leprae , a slow growing bacterium that primarily affects the skin, nerves, and mucous membranes. It is transmitted through prolonged close contact with an infected person, typically via nasal droplets. The disease manifests through symptoms such as skin lesions, loss of sensation, nerve damage, and muscle weakness. If left untreated, leprosy can lead to severe complications, including deformities, permanent disabilities, and social discrimination due to misconceptions surrounding the disease. Despite its historical stigma, leprosy is a curable disease, and early detection plays a crucial role in preventing long-term complications. The World Health Organization (WHO) recommends multidrug therapy ^[12] using a combination of rifampicin, dapsone, and clofazimine, which effectively eliminates the bacteria and stops transmission. Raising awareness, improving access to healthcare, and reducing social stigma are essential steps in eradicating leprosy and ensuring that affected individuals receive timely and effective treatment.

Challenges

• Inadequate funding: One of the major challenges in controlling Neglected tropical diseases in Nigeria is funding. The financial resources allocated to Neglected tropical diseases programs are often insufficient to sustain long-term intervention efforts. Many initiatives rely heavily on international donors, and when funding is inconsistent or insufficient, essential programs such as mass drug administration, vector control, and surveillance suffer setbacks. Without adequate investment in research, treatment, and preventive measures, progress toward eliminating these diseases remains slow, and affected communities continue to suffer. ^{[13] [14] [15]}
• Weak healthcare infrastructure: Nigeria's healthcare system, particularly in rural and underserved areas, faces significant challenges in providing adequate services for control of neglected tropical diseases. Many communities lack well equipped health facilities, trained personnel, and essential medical supplies, making it difficult for individuals to receive timely diagnosis and treatment. In some regions, healthcare centers are located far from affected populations, further complicating access to necessary interventions. This weak infrastructure limits the effectiveness of disease monitoring, early detection, and management efforts, allowing neglected tropical diseases to persist and spread. ^[16]
• Resistance and re-infection: The control of neglected tropical diseases is complicated by the challenges of parasite resistance and re infection. Many neglected tropical diseases, such as schistosomiasis and lymphatic filariasis, have complex transmission cycles that make complete eradication difficult. Environmental factors, including poor sanitation and inadequate waste management, contribute to ongoing transmission. Even after treatment, individuals living in high risk areas are often exposed to the same conditions that led to infection in the first place, increasing the likelihood of re-infection. In some cases, drug resistance develops, making treatment less effective and necessitating the development of new therapeutic strategies.
• Limited community engagement: Effective control of neglected tropical diseases requires participation from local communities, but sociocultural beliefs and a lack of awareness hinder engagement efforts. In some areas, misconceptions about disease causes and treatments lead to resistance against medical interventions. For example, traditional beliefs may attribute neglected tropical diseases to supernatural causes rather than environmental or biological factors, leading individuals to seek alternative treatments instead of medical care. Additionally, some communities are unaware of available healthcare services or fear stigmatization, which prevents them from seeking treatment. Enhancing health education and involving community leaders in awareness campaigns are crucial steps toward overcoming these barriers. ^[17]

References

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8. "Onchocerciasis (river blindness)". www.who.int. Retrieved 2025-03-23.
9. "Onchocerciasis (river blindness)". www.who.int. Retrieved 2025-03-23.
10. "Soil-transmitted helminth infections". www.who.int. Retrieved 2025-03-23.
11. "Trachoma - Symptoms and causes". Mayo Clinic. Retrieved 2025-03-23.
12. Perron, G. G.; Kryazhimskiy, S.; Rice, D. P.; Buckling, A. (2012). "Multidrug Therapy and Evolution of Antibiotic Resistance: When Order Matters". Applied and Environmental Microbiology. 78 (17): 6137–6142. Bibcode:2012ApEnM..78.6137P. doi:10.1128/AEM.01078-12. PMC   3416609 . PMID   22729549.
13. "ENDING THE NEGLECT: COST-BENEFIT ANALYSIS OF ELIMINATING NEGLECTED TROPICAL DISEASES IN NIGERIA BY 2030" (PDF). end.org.
14. Onasanya, Adeola; Oladepo, Oladimeji; Forje, Gima Humphrey; Abua, Eucheria Ekugeni; Amazigo, Uche Veronica (27 January 2025). "Evaluating stakeholder coordination and partnerships for NTD elimination in Taraba state, Nigeria: a multi-level analysis". BMC Infectious Diseases. 25 (1): 125. doi: 10.1186/s12879-025-10553-x . PMC   11770909 . PMID   39871204.
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17. "Community engagement in neglected tropical disease treatment - Treatment in Nigeria: Rethinking the needs of varying contexts" (PDF). countdown.lstmed.ac.uk.