Persistent Asymptomatic Plasmodium falciparum Driven Anemia in a Treatment Re-infection Pediatric Cohort in a Rural Health District of Cameroon

Background: Asymptomatic Plasmodium falciparum infection (APFI) resulting from partial immunity is beneficial to individuals living in malaria hyper endemic regions like Cameroon. However APFI sustains not only persistent malaria transmission in the general population but equally accounts for complications related to untreated malaria such as anemia. The aim of this study therefore was to determine the rate of anemia within a population of children with persistent APFI, living in a rural area of Cameroon. Materials and methods: A cohort of children from nursery and primary school was monitored for four months in the Bikop Health District of Cameroon. Using pretested questionnaire data was collected from 80 children less than 13 years old during the months of November 2016 and February 2017. Blood samples were collected twice by venipuncture during this period. Children with acute symptoms of malaria, fever or chills and children recently sick or under malaria treatment were excluded. Using malaria rapid diagnostic kits (RDTs) and fluorescent microscopy we screened for malaria positive people and also for the hemoglobin level using a hemoglobinometer. Results: The median age of participants was 6.5 (4-10). The rate of APFI increased from 41.25% in November 2016 to 65% in February 2017 irrespective of the use of Long Lasting Insecticidal Nets (LLIN). Similarly, the rate of anemia also increased (100% for the 2-5, 100% for the 6-9 years and 92.31% for the 10-13 years old children respectively). The changes in asymptomatic malaria associated anemia correlated positively (r=0.93, p=0.002) with increasing Plasmodium falciparum parasitemia especially with respect to moderate anemia (38.75% in the month of November and 50.00% in the month of February). Conclusion: Thus asymptomatic Plasmodium falciparum parasitemia could be a driving force behind persistent anemia in school age children in rural areas of Cameroon.