Current patterns of genetic diversity in indigenous and introduced species of land snails in Cameroon reflect isolation by distance, limited founder size and known evolutionary relationships.

The aim of this study was to gain molecular insights into patterns of genetic diversity in indigenous and introduced land snails in Cameroon. These species, Archachatina marginata and Achatina fulica, form an important source of protein in Cameroon, but widespread utilization may possibly impact natural patterns of genetic diversity of the indigenous species, while the introduced species may display signs of genetic drift. The evolutionary relationship between the indigenous and introduced species was also studied. Specimens were collected from seven sites in Cameroon. Genetic analyses using COI mitochondrial DNA data suggest that gene flow among the Ar. marginata populations screened follows a model of isolation by distance, and genetic diversity estimates for this species did not provide support for the hypothesis of loss of genetic diversity in areas of intense harvesting. Diversity in the introduced species was much lower, which is likely the signature of an introduction involving limited numbers.

Prevalence and case-control study of cerebral malaria in Limbe of the South-West Cameroon.

A study was carried out in Limbe and its environs to determine the prevalence of cerebral malaria vis- a- vis uncomplicated malaria, and to assess the importance of parasitaemia level, packed cell volume and hypoglucaemia as predictors of cerebral malaria. Data were obtained using a questionnaire administered to 650 people aged between 6 months and 70 years, and by a case-control study on 90 people (30 cases and 60 controls) aged between 6 months and fifteen years. The results of the questionnaire study revealed uncomplicated malaria prevalence rate of 50.9% as against 7.1% for cerebral malaria. The highest prevalence of these infections occurred in the 0-5 years age group, dropping in people aged 16 years and above. The case-control study revealed high parasitaemia (100,000-500,000 parasites/mm3 of blood) in uncomplicated malaria patients and hyperparasitaemia (>500,000 parasites/mm3 of blood) in cerebral malaria patients. Patients with uncomplicated malaria had either normal haemoglobin (PCV<18%). Hypoglycaemia (>40 mg glucose/dl) was recorded in 12.9%of cerebral malaria patients, but in none of the patients with uncomplicated malaria.

Microscopy is more reliable than questionnaire-based methods in the diagnosis of malaria in school children.

The objectives of the study were to determine by the use of a structured questionnaire the prevalence of malaria and its associated symptoms amongst school children and to relate these to the prevalence of malaria determined by microscopic examination. The questionnaire was administered to 840 pupils of classes 3, 5 and 7 (age range 5-16 years) in 17 primary schools of the Kumba Health District of Cameroon. Blood samples were collected from the same individuals for identification of malaria parasites. The prevalence rate by microscopic examination was 41.4% significantly higher (P<0.001) than 23.9% obtained by questionnaire survey. Headache and fever had similar prevalence rates (53.6% and 53.0% respectively) which were significantly higher (P<0.001) than the prevalence rate of malaria by microscopic examination. Other malaria hyphen;related symptoms gave rates which greatly underestimated the prevalence of malaria (P<0.001). There was no significant correlation between the prevalence rates obtained by questionnaire and the rate of malaria by microscopy. The sensitivity and specificity of these screening tests for malaria were all low. The use of the microscope as a malaria diagnostic tool at primary health care unit is strongly recommended.