House modifications for preventing malaria

Area of Science:

• Public Health
• Infectious Diseases
• Environmental Health

Background:

• Malaria remains a significant global health challenge, with historical research suggesting housing improvements could mitigate transmission.
• Previous reviews indicated house screening's potential effectiveness, prompting this updated analysis incorporating new evidence.

Purpose of the Study:

• To evaluate the impact of housing modifications designed to minimize mosquito exposure on malaria incidence and transmission.
• To synthesize evidence from randomized controlled trials and quasi-experimental studies on the effectiveness of structural housing interventions.

Main Methods:

• Searched multiple databases including Cochrane, PubMed, Embase, CAB Abstracts, and LILACS up to May 2022 for relevant trials.
• Included randomized controlled trials (RCTs), cluster-RCTs, and quasi-experimental designs investigating housing modifications and malaria outcomes.
• Extracted epidemiological and entomological data, assessing risk of bias and certainty of evidence using the GRADE approach.

Main Results:

• Seven trials (1 RCT, 6 cluster-RCTs) conducted in sub-Saharan Africa met inclusion criteria, primarily assessing screening of openings.
• House modifications likely reduced malaria parasite prevalence (moderate-certainty) and moderate to severe anemia (high-certainty).
• Effects on clinical malaria incidence were inconsistent; a potential reduction in indoor mosquito density was observed but with low certainty.

Conclusions:

• House modifications, particularly screening often combined with insecticides or "lure and kill" devices, are associated with reduced malaria parasite and anemia prevalence.
• While malaria incidence findings were mixed, these interventions show promise for reducing indoor mosquito populations.
• Further research may clarify the impact on clinical malaria and optimize intervention strategies.