Microfilariae Prevalence and its Association with Anemia Among First-time Blood Donors in Lambaréné, Gabon

Background: Anemia remains a significant public health concern in Gabon, particularly among children, adolescents, and females. Gabon is also home to two major species of filarial worms, Loa and Mansonella spp., which cause microfilaremia. The epidemiological nexus between hemoglobin (Hb) concentrations and microfilaremia in Gabonese first-time blood donors remains unknown.

Aims: To understand better the epidemiological relationship between anemia and microfilaremia to improve donor selection and management protocols.

Study design: A retrospective cohort study.

Methods: This study was conducted among first-time blood donors in Lambaréné between March 2018 and October 2019. Participants aged 16-65 years old and weighing a minimum of 50 kg were enrolled using standard donor selection criteria. An automatic hematological analyzer was used to quantify Hb concentrations, and microscopy techniques were used to detect the presence of microfilariae.

Results: Microfilariae were found in 4.8% (35/723) of the 723 first-time blood donors from Lambaréné. Anemia was classified as mild in 35.5% (257/723) and moderate in 1% (7/723). No significant associations were found between the distribution of microfilariae and variables such as age, sex, socioprofessional classification, marital status, or residence. Blood group O donors had a higher prevalence of microfilariae (6%) than non-O donors (2.7%). However, the observed difference was not statistically significant (AOR =2.3, p = 0.052). Furthermore, microfilariae were associated with increased moderate anemia (3.7% vs. 29%, AOR =15.6, p = 0.003).

Conclusion: Our findings highlight microfilaremia as a possible etiological cause of anemia among Gabonese blood donors, emphasizing the need for further research and a potential review of donor management strategies.