title: The current status of malaria epidemiology in Bolifamba, atypical Cameroonian rainforest zone: an assessment of intervention strategies and seasonal variations.
abstract: BACKGROUND
  Global malaria has been on the decline over the past decade due to expansion of interventions. The present study aimed at determining the current status of malaria epidemiology in the context of sustained interventions and seasonal variations in Bolifamba, which represents a typical semi-urban malaria endemic community in the Cameroonian rainforest.
  
  
  METHODS
  A monthly cross-sectional survey was carried out in Bolifamba, a multi ethnic semi-urban locality on the eastern flanks of Mt Cameroon, for a year during which blood samples were collected from participants and examined for malaria parasites by microscopy. Correlation analysis of seasonal/monthly malaria prevalence was done with weather data from Ekona, a nearby village with a meteorological station. Intervention strategy such as use of Insecticide Treated Bed Net (ITBN) and risk factors such as duration of stay in the locality, age and housing type were also investigated.
  
  
  RESULTS
  The results revealed a malaria prevalence of 38.3 % in the rainy season, which was significantly higher than 24.4 % observed in the dry season (P < 0.0001). A high prevalence of asymptomatic malaria which was more than double the prevalence of symptomatic malaria on a monthly basis was observed, 30.7 % vs 17.8 % in the rainy and dry season respectively (p < 0.0001) and asymptomatic malaria was significantly associated with anemia (p < 0.005). April was the peak month of malaria prevalence and coincided with peak periods of both asymptomatic and symptomatic malaria. The Plasmodium falciparum parasite rates in the 2- up to 10-years age group (PfPR(2-10)) was 40.8 %. The regular use of ITBN was significantly associated with low prevalence of 31.7 % as opposed to irregular or non-usage of ITBN 38.2 % (p < 0.05). Log of parasite load was found to initially increase to 2.49 with less than 5 years of stay, and decreased gradually with increasing duration of stay in the locality (p = 0.046). Climatic factors were significantly and positively associated with monthly malaria prevalence and the strongest predictors of malaria prevalence were rainfall and minimum temperature with r values of 0.563 and 0.6 respectively.
  
  
  CONCLUSIONS
  The study highlights the role of seasonal change in modifying malaria prevalence during the year and the beneficial effect of ITBN. It also underscores a sublime problem of asymptomatic malaria associated with anemia, and indicates that partial immunity is acquired with prolonged stay in Bolifamba. This preliminary result is the basis of ongoing work to identify the antigens involved in acquired immunity.
authors.affiliation: Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon. nyasab@yahoo.co.uk.|Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon. nyasab@yahoo.co.uk.
authors.forename: Raymond Babila
authors.initials: RB
authors.lastname: Nyasa
authors.affiliation: Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon. zofden@yahoo.com.
authors.forename: Denis
authors.initials: D
authors.lastname: Zofou
authors.affiliation: Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon. hkimbi@yahoo.co.uk.
authors.forename: Helen Kuokuo
authors.initials: HK
authors.lastname: Kimbi
authors.affiliation: Department of Environmental Science, Faculty of Science, University of Buea, Buea, Cameroon. princesskum1987@yahoo.com.
authors.forename: Karin Mbei
authors.initials: KM
authors.lastname: Kum
authors.affiliation: Mboppi Baptist Hospital, Douala, Cameroon. rolinaro@gmail.com.
authors.forename: Roland C
authors.initials: RC
authors.lastname: Ngu
authors.affiliation: Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon. vpk.titanji@yahoo.com.|Cameroon Christian University, PO Box 5, Bali, NW, Cameroon. vpk.titanji@yahoo.com.
authors.forename: Vincent P K
authors.initials: VP
authors.lastname: Titanji
mesh_terms: D000293:Adolescent; D000328:Adult; D000740:Anemia / Q000453:epidemiology / Q000382:microbiology; D002163:Cameroon / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D057148:Insecticide-Treated Bednets / Q000706:statistics & numerical data; D008288:Malaria / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000302:isolation & purification; D015995:Prevalence; D065947:Rainforest; D012307:Risk Factors; D012621:Seasons; D055815:Young Adult