BackgroundHaematologic abnormalities are features in Plasmodium falciparum infection, and anaemia is an inevitable outcome. This study examines the influence of malaria status and altitude on haematologic parameters in school-aged pupils.MethodsA cross-sectional study was conducted among 728 school pupils aged between four and 15 years at three different altitudinal ranges along the slope of the Mount Cameroon region. The investigative methods included the use of questionnaire, clinical evaluation and laboratory investigations. Blood sample collected from each child was used for the preparation of blood films for detection of malaria parasites and assessment of malaria parasite density as well as full blood count determination using an automated haematology analyzer.ResultsThe prevalence of malaria in the study population was 33.8% and 64.2% (158/246) of these were asymptomatic (AM). Pupils in lowlands had a significantly (P <0.05) prevalence (95% confidence interval, CI) of malaria (60.6%, CI = 54.6–65.9%) than those in middle belt (29.1%, CI = 23.9–34.8%) and highlands (7.7%, CI = 6.1–9.8%), while those in middle belt had significantly higher geometric mean parasite density (475) than those in lowlands (233) and highlands (388). The prevalence of malaria was significantly higher in children that presented with fever (40.4%, CI = 33.8–47.2%) when compared with afebrile subjects (31%, CI = 27–35.2%). Pupils with AM had a higher prevalence of leucopaenia (43.7%, CI = 35.8–51.8%), microcytosis (27.2%, CI = 20.5–34.9%), hypochromasia (27.8%, CI = 21–35.5%) and thrombocytopaenia (14.9%, CI = 8.9–22.8%) when compared with those with clinical malaria (CM). All mean haematological parameters were comparable in pupils with CM and AM, except for the mean white blood cell (WBC) counts. Pupils with AM had significantly lower (P = 0.02) mean WBC counts (5.1 ± 2.5 × 109/L) than those with CM (5.9 ± 2.3 × 109/L). Age, altitude and malaria parasitaemia was of significant influence on several haematological parameters.ConclusionAltitude influenced the distribution and density of malaria parasites and was of confounding influence on the haematologic profiles. These results highlight the insidious effects of AM on the haematologic components.

BackgroundRapid demographic growth in Douala city, Cameroon, has resulted in profound ecological and environmental changes. Although demographic changes can affect anopheline mosquito breeding sites, there is a lack of understanding about the epidemiological impact that such changes might have on vector ecology and malaria transmission.MethodsA 12-month entomological study was conducted in a highly populated district of Douala called Ndogpassi. Adult mosquitoes were collected using two methods: 1) human landing catches (HLC); and 2) Centers for Disease Control and Prevention (CDC) light traps; these methods were used twice monthly from January to December 2011. Mosquito genus and species were identified with morphological and molecular diagnostic tools. The sampling efficiency of the CDC light trap and HLC were compared. Anopheles gambiae infection with Plasmodium falciparum was detected using ELISA. Susceptibility to DDT, permethrin, and deltamethrin insecticides were also determined.ResultsA total of 6923 mosquitoes were collected by HLC (5198) and CDC light traps (1725). There was no equivalence in the sampling efficiency between light traps and human landing catches (P > 0.01). With 51% of the total, Culex was the most common, followed by Anopheles (26.14%), Mansonia (22.7%) and Aedes (0.1%). An. gambiae ss (M form) comprised ~98% of the total anophelines collected. An. gambiae had a biting rate of 0.25 to 49.25 bites per human per night, and was the only species found to be infected with P. falciparum. A P. falciparum infection rate of 0.5% was calculated (based on enzyme-linked immunosorbent assays using the circumsporozoite surface protein). The entomological inoculation rate was estimated at 31 infective bites per annum. Insecticide susceptibility tests on An. gambiae females revealed a mortality rate of 33%, 76% and 98% for DDT, permethrin and deltamethrin, respectively. The West African kdr allele (L1014F) was detected in 38 of the 61 An. gambiae analyzed (62.3%).ConclusionsThe present study revealed seasonal malaria transmission in Douala. High levels of An. gambiae were detected along with a high prevalence of insecticide resistance in this vector population. These findings highlight the need to promote use of insecticide-impregnated bed nets in Douala.

Aims:This study aimed at determining the prevalence, parasite density and risk factors associated with urinary schistosomiasis (US) in the Ikata-Likoko area, Cameroon.

Background In 2014, a study in Munyenge revealed a high prevalence of urogenital schistosomiasis (UGS) among pregnant women. This study investigated he prevalence and risk factors of UGS in pregnancy following scale-up of piped water sources from 2014 to 2017. Secondly, we compared stream usage, stream contact behaviour, infection rate and intensity with the findings of 2014. Methods Consenting pregnant women reporting for antenatal care (ANC) in the different health facilities were enrolled consecutively between November 2016 and January 2018. Information on age, gravidity status, residence, marital status, educational level, occupation, household water source, frequency of contact with water and stream activities were obtained using a semi-structured questionnaire. Urine samples were examined for the presence of microhaematuria and S. haematobium ova using test strip and filtration/microscopy methods respectively. Data were analysed using univariate and multivariate regression analyses and relative risk reductions calculated. Results Of the 368 women enrolled, 22.3% (82) were diagnosed with UGS. Marital status (single) (aOR = 2.24, 95% CI: 1.04–4.79), primary - level of education (aOR = 2.0; 95% CI: 1.04–3.85) and domestic activity and bathing in the stream (aOR = 3.3; 95% CI: 1.83–6.01) increased risk of S. haematobium infection. Meanwhile, fewer visits (< 3 visits/week) to stream (aOR = 0.35, 95% CI = 0.17–0.74) reduced exposure to infection. Piped water usage was associated with reduced stream usage and eliminated the risk of infection among women who used safe water only. Compared with the findings of 2014, stream usage (RRR = 23 95% CI: 19–28), frequency (≥ 3 visits) (RRR = 69 95% CI: 59–77) and intensity of contact with water (RRR = 37 95% CI = 22–49) has reduced. Similarly, we observed a decrease in infection rate (RRR = 52, 95% CI = 40–62) and prevalence of heavy egg intensity (RRR = 71, 95% CI = 53–81). Conclusion Following increased piped water sources in Munyenge, S. haematobium infection has declined due to reduced stream contact. This has important implication in the control of UGS in pregnancy. Electronic supplementary material The online version of this article (10.1186/s12889-019-6659-7) contains supplementary material, which is available to authorized users.

Aims: Determine factors associated with malaria infection, the prevalence of asymptomatic carriage of malaria parasites and fevers of non malarial origin. Study Design: This was a cross-sectional study.