Background Soil transmitted helminthiasis (STH) remains a major public health problem worldwide. WHO has recommended a number of strategies for the control of STH, but due to logistical and financial constraints, only school-based deworming using Albendazole/Mebendazole is frequently used. However, this does not take into consideration other age groups who share similar risk and rate of infection, and the drugs used showed reduced efficacy on certain species of soil-transmitted helminths. Some trials have demonstrated that the combination of Albendazole/Mebendazole and Ivermectin a better potential for the interruption of transmission of STH. However, the introduction of ivermectin in the treatment regimen presents a high risk of occurrence of potentially fatal serious adverse events (SAEs) occurring after administration of ivermectin among individuals heavily infected with loiasis. This study aimed to investigate the proportion of individuals coinfected with STH and loiasis, in order to determine which proportion of the population would be at-risk of SAEs if the regimen including ivermectin was used.

Methods A cross-sectional survey was conducted in 2022 in three health districts (Awae, Akonolinga and Okola) in the Centre Region of Cameroon. Capillary blood and stool samples were collected for the diagnosis of loiasis and STH, respectively. Calibrated thick blood smears were prepared for the enumeration of Loa loa microfilariae in the blood, and stool samples were analyzed by the Mini-FLOTAC and Kato-Katz methods.

Results Overall, 660 individuals were tested for both loiasis and STH in the three health districts, of which 23 (3.5%; 95%CI: 2.3–5.2) were coinfected. The overall coinfection rate was 5.3% (95% CI: 2.3–11.7) in Okola, 3.9% (95%CI: 2.3–6.5) in Akonolinga and 2.2% (95%CI:0.9–5) in Awae. Of the coinfected individuals, 69.5% (95%CI: 49.1–84.4) had light L. loa infection while 26.1% (95%CI: 12.5–46.5) had moderate infection and 0.04% (95%CI: 0.007–21) had heavy infection.

Conclusion The risk of developing SAEs remains in the population.