Characterizing the larval habitats of the main malaria vector, Anopheles stephensi, in southern Iran.

BACKGROUND

Vector-borne parasitic infectious diseases, particularly malaria, pose significant challenges to global public health. Understanding the environmental factors influencing the growth and reproduction of malaria vector is crucial for developing effective control strategies. This research aims to determine the abundance of larvae and the physicochemical parameters of breeding sites associated with Anopheles stephensi in southern.

METHODS

A field study was conducted using standardized sampling techniques. Water samples were collected from various habitats, and physicochemical factors such as pH, temperature, turbidity, and concentrations of dissolved organic matter were measured. The population density of An. stephensi larvae was recorded and analysed in relation to these environmental parameters.

RESULTS

A total of 1943 An. stephensi larvae were collected, with the highest abundance found in Hormoodar village. Monthly data indicated that November was the peak for larval abundance, accounting for 463 larvae, while July recorded the lowest counts. Larval abundance per 10 dipper samples was 18, with Hormoodar consistently supporting a higher density of larvae, likely due to favourable environmental conditions. Environmental analysis revealed average monthly temperatures ranging from 9 °C in February to 35 °C in August, with higher temperatures correlating with increased larval abundance. Water temperature ranging from 12 °C in February to 35 °C in August, with significant correlations observed between warmer water temperatures and larval counts (p-value < 0.05). Most larval habitats were classified as temporary stagnant water bodies, with varying degrees of vegetation cover and substrate types. Chemical analyses showed neutral pH levels across habitats, but higher turbidity and electrical conductivity in Geno village compared to the other regions, indicating distinct environmental characteristics that may influence larval survival and development.

CONCLUSION AND DISCUSSION

This study highlights the critical role of physicochemical parameters in shaping the larval habitats of An. stephensi, a significant malaria vector in southern Iran. Understanding these environmental factors is vital for developing effective malaria control strategies, particularly in regions facing increasing insecticide resistance. The findings underscore the importance of managing artificial breeding sites to mitigate malaria transmission effectively.