“The number of malaria mosquitoes in Zanzibar is low compared to many other places, but the mosquitoes that are there are biting both indoors and outdoors, including during the evenings before people have gone to sleep under their nets,” says CCP's April Monroe, PhD, the leader of the study.

In 2026, mosquitoes in Zanzibar remain a significant nuisance, particularly during the rainy seasons (March–May and November). While the archipelago has made incredible strides in reducing malaria prevalence to near 1%, the risk is not zero, and "imported" cases from mainland Tanzania continue to be a concern for health officials. The mosquitoes are most active during dusk and dawn. Most reputable hotels and resorts provide mosquito nets over beds and use "fogging" treatments to keep local populations down. However, travelers are strongly advised to use a repellent containing at least 30% DEET or Picaridin and to wear long sleeves in the evenings. Beyond malaria, mosquitoes can also transmit Dengue fever, which has seen sporadic outbreaks in East Africa. For most tourists, the "itch" is the biggest problem, but taking a prophylactic (like Malarone) is still a common recommendation for those planning to spend significant time in rural areas or near standing water.