The current status of malaria epidemiology in Bolifamba, atypical Cameroonian rainforest zone: an assessment of intervention strategies and seasonal variations

Abstract

BackgroundGlobal 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.MethodsA 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.ResultsThe 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.ConclusionsThe 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.

Malaria parasitaemia, anaemia and malnutrition in children less than 15 years residing in different altitudes along the slope of Mount Cameroon: prevalence, intensity and risk factors

“…However, the prevalence is lower than the 66.9% reported earlier in children ≤ 14 in Tole community [ 27 ] and the 45.3% in pupils between 4 and 16 years in other areas in the Mount Cameroon area [ 2 ]. Even though a lower prevalence has been reported by Apinjoh et al [ 5 ] and Nyasa et al [ 36 ] in the Mount Cameroon area, the GMPD observed in the study (413 parasites/µL of blood) is lower than the 1721 parasites/µL of blood reported by Apinjoh et al [ 5 ]. Although, the Mount Cameroon area has an equatorial climate characterized by abundant rainfall and constant humidity which are factors favouring intense and perennial transmission of the malaria parasite [ 37 ], the decrease in malaria morbidity is thought to be the result of sustained control measures including implementation of long lasting insecticide nets and use of artemisinin-based combination therapy (ACT) as recommended by the World Health Organization.…”

Burden of moderate to severe anaemia and severe stunting in children < 3 years in conflict-hit Mount Cameroon: a community based descriptive cross-sectional study

“…In addition, it is higher than the 59.7% reported in pre-school children in Gaza Strip-Palestine [29] and the 54% reported in internally displaced children in Edo-Nigeria [30]. While the prevalence of malaria parasite in this population is lower than previously reported in children < than 5 years [10,31,32], that of anaemia has experienced an increase. The surge in prevalence of anaemia which is an important outcome indicator of poor nutrition and health may reflect the living conditions, poverty and increase in food EBF Exclusive breastfeeding, MF Mixed feeding, NBF No breast feeding.…”

Review of malaria situation in Cameroon: technical viewpoint on challenges and prospects for disease elimination

“…Studies conducted in the South-West region after LLINs mass campaigns scale-up, on children aged one month to 14 years-old, indicated a prevalence varying from 9 to 41.5% ( n = 454) during the rainy season in Tiko, Limbé, Idenau, Mutengene and Buéa [18, 68, 70–75]. High parasite prevalence varying from 41.7 to 56.2% ( n = 828) along the slope of Mount Cameroon was also recorded [76, 77]. The social crisis affecting the North-West and South-West regions of the country with a displaced population, could be affecting malaria epidemiology in the area and this could constitute an enormous challenge that could impede malaria elimination or control efforts in these regions and neighbouring regions.…”