Loa loa Life Cycle

1. When an infected fly bites a person, it deposits Loa loa larvae onto the person's skin, and the larvae enter the bite wound.

2. The larvae mature into adults in subcutaneous tissue.

3. Adults produce microfilariae, which circulate in blood during the day and are found in the lungs at night. Microfilariae may be present in spinal fluid, urine, and sputum.

4. A fly ingests microfilariae when it bites the person.

5. In the fly, the microfilariae travel to the midgut then to the thoracic muscles.

6–7. There, the microfilariae develop into first-stage (L1) larvae and subsequently into third-stage (L3) infective larvae.

8. Larvae travel to the fly's proboscis and can be transmitted to other people when the fly bites them.