Malaria: Epidemiology, National Programme and Management in North-Eastern India

10-mark answer, Park-based

Definition

1. Epidemiology

Agent factors

• Causative organisms: P. vivax, P. falciparum, P. malariae, P. ovale and P. knowlesi.
• In India, P. vivax and P. falciparum account for almost all indigenous malaria.
• P. vivax produces dormant liver forms, hypnozoites, causing relapses.
• P. falciparum can cause cerebral malaria, severe anaemia, acute kidney injury, shock and death.

Reservoir

• Mainly infected human beings, including asymptomatic carriers.
• Female Anopheles mosquito acts as the biological vector.

Mode of transmission

1. Bite of infected female Anopheles mosquito, the usual route.
2. Blood transfusion, contaminated needles and congenital transmission, rarely.

Vector factors

• Anopheles culicifacies: rural plains.
• Anopheles stephensi: urban malaria.
• Anopheles fluviatilis: foothills and forest areas.
• In North-East India: Anopheles minimus and Anopheles baimaii are highly efficient vectors.

Host factors

• All ages are susceptible, but severe disease is common in young children, pregnant women, non-immune migrants and malnourished persons.
• Partial immunity develops after repeated exposure in endemic areas.
• Sickle-cell trait provides some protection against severe P. falciparum malaria.

Environmental and social factors

• Transmission increases with rainfall, humidity, warm temperature, stagnant water, poor housing and inadequate vector control.
• Forested, hilly, tribal, border and difficult-to-access regions are high-risk areas.
• Migration, population movement, conflict, poor access to diagnosis and incomplete treatment sustain transmission.

Epidemiological indices

• Annual Parasite Incidence (API): Confirmed malaria cases during one year per 1,000 population.
• Annual Blood Examination Rate (ABER): Blood smears examined in one year per 100 population. Desired level is at least 10%.
• Slide Positivity Rate (SPR): Positive slides per 100 slides examined.
• Slide Falciparum Rate (SFR): P. falciparum-positive slides per 100 slides examined.
• Pf percentage: P. falciparum cases as percentage of total malaria cases.

2. National Malaria Control Programme

Evolution

Goal

Major components / activities

1. Early case detection and complete treatment
   • Test every suspected fever case using microscopy or RDT.
   • Prompt species-specific treatment.
   • Referral and treatment of severe malaria.
2. Integrated vector management
   • Indoor residual spraying (IRS) in high-risk areas.
   • LLINs or insecticide-treated nets.
   • Larval source reduction and environmental management.
   • Personal protective measures such as repellents, protective clothing and screened houses.
3. Surveillance
   • Passive and active surveillance.
   • Case-based reporting, investigation and response.
   • Monitoring API, ABER, SPR, SFR and Pf%.
4. Targeted interventions
   • Focus on tribal, forest, foothill, migrant, border and conflict-affected populations.
   • Special focus on high-burden districts and difficult-to-reach areas.
5. Capacity building and logistics
   • Training of health workers.
   • Supply of RDTs, antimalarials, insecticides and LLINs.
   • Monitoring, evaluation, operational research and drug-resistance surveillance.
6. Intersectoral and cross-border coordination
   • Essential in inter-state and international border areas, particularly in the North-East.
     Park’s Textbook of Preventive and Social Medicine, p. 469.

3. Special epidemiology of North-Eastern India

Reasons for high risk

• Dense forests, hills, heavy rainfall and favourable climate for mosquito breeding.
• Large tribal and remote populations with reduced access to health facilities.
• International borders and migration, causing importation and spread of malaria.
• Efficient vectors: Anopheles minimus and Anopheles baimaii.
• Transmission is commonly perennial, with a seasonal rise from April to September.
• P. vivax is especially important in Arunachal Pradesh, Nagaland and Manipur; P. falciparum predominates in several southern and forested belts.

4. Diagnosis and treatment

Diagnosis

• Suspect malaria in every acute fever case from an endemic area.
• Confirm by:
  • Peripheral blood smear microscopy, thick and thin films, or
  • Rapid diagnostic test (RDT).
• Start treatment immediately after confirmation, especially for P. falciparum.
  Park’s Textbook of Preventive and Social Medicine, p. 308.

A. Uncomplicated P. vivax malaria

• Chloroquine: total 25 mg base/kg over 3 days:
  • Day 1: 10 mg/kg
  • Day 2: 10 mg/kg
  • Day 3: 5 mg/kg
• Primaquine: 0.25 mg base/kg once daily for 14 days for radical cure and prevention of relapse.

B. Uncomplicated P. falciparum malaria in North-Eastern states

• Add single-dose primaquine 0.75 mg base/kg on day 2 to reduce transmission.
• ACT-AL is not recommended in the first trimester of pregnancy or in children weighing less than 5 kg.
• Primaquine is contraindicated in pregnancy, infancy and G6PD deficiency.
  Park’s Textbook of Preventive and Social Medicine, pp. 309-310.

C. Severe malaria: emergency management

1. Admit and urgently refer to a hospital.
2. Give parenteral artesunate as per national protocol.
3. Once the patient can take oral drugs, complete a full course of ACT.
4. Supportive treatment:
   • Airway, oxygen and careful fluid balance.
   • Check and correct hypoglycaemia.
   • Treat seizures.
   • Antipyretics for fever.
   • Blood transfusion for severe anaemia if indicated.
   • Dialysis for renal failure where required.
   • Monitor urine output, haemoglobin, glucose, renal function and parasitaemia.

Conclusion

XDR-TB: Extensively Drug-Resistant Tuberculosis

1. Rifampicin-resistant with or without isoniazid resistance, that is MDR/RR-TB, and
2. Resistant to any fluoroquinolone: levofloxacin or moxifloxacin, and
3. Resistant to at least one other Group A drug: bedaquiline or linezolid.

XDR-TB = MDR/RR-TB + fluoroquinolone resistance + resistance to bedaquiline and/or linezolid.

Related definitions

Old definition, important for exams

MDR-TB plus resistance to any fluoroquinolone and at least one second-line injectable drug: amikacin, kanamycin, or capreomycin.

Diagnosis

• Confirm TB bacteriologically with sputum smear, molecular test and culture where possible.
• Perform rapid molecular testing for rifampicin resistance and fluoroquinolone resistance.
• Drug-susceptibility testing for bedaquiline and linezolid is required to classify XDR-TB accurately.
• Assess HIV status, diabetes, nutritional status, chest radiograph, and extrapulmonary involvement.

Management principles

• Refer to a DR-TB centre or specialist programme immediately.
• Use an individualized, all-oral, DST-guided regimen under national TB programme guidance.
• Ensure adherence support, contact investigation, nutrition support, adverse-effect monitoring and infection-control measures.
• Monitor for bedaquiline-associated QT prolongation and linezolid-associated neuropathy, myelosuppression and optic toxicity.

XDR-TB Regimen: Park-based

Duration

• 20 months for XDR-TB.
  Park’s Textbook of Preventive and Social Medicine, p. 225.

All-oral longer regimen shown in Park for MDR/RR-TB

18-20 months: Bdq (6 months) + Lfx + Lzd + Cfz + Cs

Important XDR-TB point

• Delamanid
• Pyrazinamide
• Ethambutol
• Ethionamide/prothionamide
• PAS
• Imipenem-cilastatin or meropenem
• Amikacin only if proven susceptible and necessary

Write in exam

XDR-TB is treated under NTEP at a Nodal DR-TB Centre with an individualized DST-guided all-oral longer regimen for 20 months. Park’s longer all-oral regimen is Bdq for 6 months plus Lfx, Lzd, Cfz and Cs; however, in XDR-TB, fluoroquinolone-resistant drugs are excluded and appropriate effective Group B/C drugs are substituted according to DST.