Vector and reservoir control for preventing leishmaniasis.

Area of Science:

• Medical Entomology
• Infectious Diseases
• Public Health Interventions

Background:

• Leishmaniasis, caused by the Leishmania parasite and transmitted by sandflies, presents as cutaneous (CL) or visceral (VL) forms.
• Control strategies focus on reducing parasite transmission through vector control (limiting sandfly contact) and reservoir control (reducing infected animal populations).

Purpose of the Study:

• To evaluate the effectiveness of vector and reservoir control interventions for preventing both cutaneous and visceral leishmaniasis.

Main Methods:

• A systematic review of randomized controlled trials (RCTs) was conducted, searching multiple databases up to January 2015.
• Included RCTs assessed vector control methods like indoor residual spraying (IRS), insecticide-treated bednets (ITNs), and insecticide-treated clothing in leishmaniasis-endemic regions.
• Evidence quality was assessed using the GRADE approach, with a focus on clinical outcomes.

Main Results:

• Insecticide-based interventions, including IRS, ITNs, and insecticide-treated sheets, showed reduced CL incidence compared to no intervention, though evidence quality varied (moderate to low).
• Insecticide-treated curtains also demonstrated a significant reduction in CL incidence.
• Limited evidence exists for visceral leishmaniasis, with one trial of ITNs showing no significant difference, and dog culling studies reporting reduced seroconversion but not clinical disease.

Conclusions:

• Insecticides targeting sandfly populations show potential for reducing CL incidence.
• Insufficient evidence exists to definitively recommend specific insecticide application methods (e.g., IRS vs. ITNs vs. treated materials) for optimal leishmaniasis control.
• Further high-quality research is needed to compare the efficacy of different vector control strategies for both CL and VL.