Introduction: Female Anopheles mosquitoes are the exclusive vectors of malaria parasites in Sudan, along with several metazoan parasites such as filarial worms and viruses. The sense of smell is one of the most important senses that mosquitoes use for long-range host-seeking. Carbon dioxide from the breath of humans and animals is a strong attractant of female mosquitoes.
Methods: This correlational study was performed in Al-Qaddal Center for Malaria Research in Sinnar State, Sudan. In this study, individual volunteers were topically applied Ocimum bascilicum oil to test its repellency activity. O. bascilicum oil was tested at four different concentrations (30%, 50%, 70%, and 100% v/v), respectively.
Results: Based on the obtained results, the oil exhibited the highest repellency activity at 100% concentration, and the average repellency rate was 100%. However, the lowest repellency activity was at 30% concentration, and the average repellency rate was 45%. Diethyltoluamide 13% (Soffell cream) was tested as a reference repellent cream and showed the same effect as O. bascilicum oil at 70% concentration, and the average repellency rate was 94%.
Conclusion: The results demonstrated that O. bascilicum oil had high repellency activity against female Anopheles mosquitoes, and thus can be used as mosquito natural repellent.