Insecticide-treated nets for malaria — DTM&H MCQ

Correct answer: C — Long-lasting insecticidal nets with prompt testing and treatment access

The correct answer is C, long lasting insecticidal nets with prompt testing and treatment access. Anopheles mosquitoes, the vectors for malaria, feed predominantly indoors at night, which makes bed nets treated with insecticide a highly effective barrier against the specific behaviour described in the stem. UKHSA guidance for malaria prevention emphasises that travellers and residents in endemic areas should sleep under a well maintained insecticide treated net as a core bite avoidance measure, alongside rapid access to diagnostic testing and treatment (the ABCD approach: Awareness, Bite prevention, Chemoprophylaxis, prompt Diagnosis). Where insecticide resistance is emerging, nets still provide a physical barrier and residual chemical effect, so surveillance informs product choice rather than abandoning nets. Combining vector control with prompt diagnosis and treatment addresses both transmission reduction and case management, matching the resource realities of a district hospital setting. Why the other options are wrong: E. Yellow fever vaccination of children: this targets a different mosquito borne flavivirus transmitted by day biting Aedes species, not the night biting Anopheles responsible for malaria, so it does nothing to reduce malaria transmission. B. Monthly praziquantel for households: praziquantel treats schistosomiasis, a helminth infection acquired through freshwater contact, and has no role in malaria prevention or treatment. A. Container emptying as the main malaria measure: emptying containers targets Aedes breeding sites for dengue and Zika control, whereas Anopheles vectors typically breed in larger natural water bodies, so this is not the primary malaria intervention. D. Avoidance of raw freshwater crab: this reduces paragonimiasis risk from consuming undercooked crustaceans, an unrelated food borne parasitic infection with no bearing on mosquito borne malaria transmission. Key point: because the vector bites indoors at night, insecticidal nets plus rapid access to testing and treatment remain the most appropriate malaria prevention strategy regardless of local insecticide resistance patterns.

Reference: UKHSA, Guidelines for malaria prevention in travellers from the UK, 2024 (bite prevention and ABCD approach), gov.uk