Speculation on the possibility for introducing Anopheles stephensi as a species complex: preliminary evidence based on odorant binding protein 1 intron I sequence.

Background: Anopheles stephensi is considered an important malaria vector in Iran, Asia, and recently in the Horn of Africa. Recently, Ansteobp1 intron I sequence has been introduced a new molecular marker for identification of its biological forms including, mysorensis, intermediate and type, using insectary colony specimens.

Methods: In the current study, new marker ability in molecular identification of biological forms has been evaluated with An. stephensi specimens collected from Iran and Afghanistan malarious provinces. Following DNA extraction and PCR amplification, sequence analysis and constructed phylogenetic tree revealed that type and intermediate forms are distributed in Iran.

Results: The specimens collected from Afghanistan identified as intermediate and mysorensis forms. Therefore, intermediate form is sympatric species in both countries. Based on the results of Ansteobp1 intron I sequences, An. stephensi could be suggested as new Anopheles complex species including An. stephensi sibling A (type form), An. stephensi sibling B (intermediate form) and An. stephensi sibling C (mysorensis form). This is the first report on the presence of An. stephensi biological forms in Afghanistan.

Conclusions: Iran is going to eliminate malaria transmission from the country, precise species identification, especially in complex species will be helpful in the prevention of malaria resurgence in the country, mainly because of common fauna of Anopheles species and through border malaria and population movement within Afghanistan, Pakistan, and Iran.