SLEEPING SICKNESS

Source: Downtoearth

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Context

• In a landmark achievement, Chad has become the first country in 2024 and the 51st globally to eliminate a neglected tropical disease (NTD) — the gambiense form of human African trypanosomiasis (HAT), also known as sleeping sickness.
• This historic announcement by the World Health Organization (WHO) highlights significant progress in the fight against diseases that primarily affect low-income populations.

Details

Key Strategies for Elimination

Early Diagnosis and Treatment

• Improved Healthcare Access: Facilitated faster identification of cases in remote areas
• New Treatment Protocols: Introduction of more effective and easier-to-administer drugs

Tsetse Fly Control

• Targeted Programmes: Utilization of traps and insecticides designed to attract and kill tsetse flies
• Breaking Transmission Cycle: Reduced tsetse fly population and transmission rates

Outcomes

• Dramatic Reduction in Cases: No new infections reported in recent years
• Verification by WHO: Thorough review of case surveillance, diagnostic testing, and vector control measures
• Official Declaration: Chad declared free from gambiense sleeping sickness as a public health problem in April 2024

Global Context

• WHO Validation: Gambiense HAT has been eliminated as a public health problem in seven other countries (Togo, Benin, Ivory Coast, Uganda, Equatorial Guinea, Ghana, and Chad). The rhodesiense form has been eliminated in Rwanda.
• Global Target: Elimination of at least 100 NTDs by 2030

Sleeping Sickness (African Trypanosomiasis)

• Sleeping sickness, or African Trypanosomiasis, is a parasitic disease caused by protozoa of the genus Trypanosoma.

Causative Agent

• Pathogen: Trypanosoma brucei
  • Subspecies:
• Trypanosoma brucei gambiense(West African sleeping sickness) - 92% of cases
• Trypanosoma brucei rhodesiense(East African sleeping sickness) - 8% of cases

Transmission

• Vector: Tsetse fly (Glossinaspecies)
• Mechanism: The tsetse fly becomes infected by feeding on an infected human or animal, and the parasites multiply in the fly. When the fly bites another human, the parasites are transmitted through the fly's saliva.

Epidemiology

• Geographical Distribution: Sub-Saharan Africa
• Risk Factors: Rural areas, poverty, proximity to rivers or water bodies where tsetse flies breed

Clinical Presentation

Two Stages:

1.Hemolymphatic Stage:

• Symptoms:
  • Fever
  • Headache
  • Joint pains
  • Lymphadenopathy (enlarged lymph nodes)
  • Itching
• Signs:
  • Winterbottom's sign (swollen lymph nodes at the back of the neck)

2.Neurological Stage:

• Symptoms:
  • Confusion
  • Sensory disturbances
  • Poor coordination
  • Sleep cycle disruption (hence "sleeping sickness")
• Complications:
  • Severe neurological impairment
  • Coma

Neglected Tropical Diseases (NTDs)

• Neglected Tropical Diseases (NTDs) are a diverse group of infections that primarily affect marginalized communities in the developing regions of Africa, Asia, and the Americas.
• These diseases are caused by various pathogens, including viruses, bacteria, protozoa, and parasitic worms.
• They are prevalent in tropical areas where access to clean water and safe waste disposal is limited.

Key Characteristics

• Affected Regions: Tropical and subtropical regions
• At-risk Populations: Marginalized communities, often in rural areas, urban slums, and conflict zones
• Causing Agents: Viruses, bacteria, protozoa, parasitic worms
• Transmission: Through vectors (insects), contaminated water and soil, direct contact, and food

Common NTDs

• Snakebite Envenomation
• Scabies
• Yaws
• Trachoma
• Leishmaniasis
• Chagas Disease

Challenges

• Funding: NTDs receive less funding for research and treatment compared to diseases like tuberculosis, HIV/AIDS, and malaria
• Healthcare Access: Limited access to healthcare facilities and resources
• Sanitation: Poor sanitation and lack of clean water exacerbate the spread of NTDs

London Declaration on NTDs

• Adopted: January 30, 2012
• Significance: Recognized the global burden of NTDs
• Participants: WHO, World Bank, Bill and Melinda Gates Foundation, global pharmaceutical companies, and national government representatives
• Pledge: To end the burden of NTDs through coordinated global efforts

WHO’s New Roadmap for 2021–2030

• Approach:
  • From Measuring Process to Measuring Impact: Shift focus from process metrics to impact metrics
  • Collaborative Work Across Sectors: Move from disease-specific planning to integrated, cross-sector collaboration
  • Country Ownership: Transition from externally driven agendas to programs that are country-owned and financed

Global NTD Scenario

• Prevalence: Affect more than a billion people globally
• Preventable and Treatable: Despite this, NTDs continue to cause severe health, social, and economic consequences
• Global Impact: 20 NTDs impact over 1.7 billion people worldwide

NTDs in India

• Burden: India carries the largest burden of at least 11 NTDs, including kala-azar and lymphatic filariasis
• Vulnerable Populations: Diseases predominantly affect the poorest and most vulnerable populations

Indian Initiatives to Eliminate NTDs

• Accelerated Plan for Elimination of Lymphatic Filariasis (APELF):
  • Launched: 2018
  • Objective: Intensify efforts towards the elimination of lymphatic filariasis and other NTDs
• Kala-Azar Elimination Efforts:
  • Regional Alliance: Established by the governments of India, Bangladesh, and Nepal in 2005
  • Support: WHO-supported initiative for early diagnosis, treatment, and improved disease surveillance and control of sandfly populations
• Successful Elimination of Several NTDs:
  • Guinea Worm: Eliminated
  • Trachoma: Eliminated
  • Yaws: Eliminated

Sources:

Downtoearth

PRACTICE QUESTION Q.  Consider the following statements regarding Neglected Tropical Diseases (NTDs): NTDs predominantly affect populations in tropical and subtropical regions. NTDs include diseases such as dengue, rabies, and chikungunya. NTDs are usually associated with poor living conditions and lack of access to healthcare. Which of the statements given above is/are correct? a) 1 and 2 only b) 1 and 3 only c) 2 and 3 only d) 1, 2, and 3 Answer: b)