EPIDEMIOLOGIC FEATURES OF ACUTE APPENDICITIS IN A TROPICAL AFRICAN POPULATION

BACKGROUND: The true incidence rate of appendicitis in Cameroon and the magnitude of etiological factors in appendicitis are unknown. AIM: To describe the epidemiology of acute appendicitis in the Northwestern region of Cameroon. MATERIALS AND METHODS: A retrospective population-based cohort study was conducted to assess the demographic features, incidence and seasonal variation of acute appendicitis using the medical database of two Mission Hospitals in the Northwestern Region, Cameroon from January 2006 to January 2016. The National Institute of Statistics, Bamenda Regional Office, Bui-Division -Population Data of Cameroon in 2016 was used to estimate the standardized annual incidence of appendicitis in the locality. Hospital A is a 200-bed Mission Hospital (with 50 surgical beds), while Hospital B is a 250-bed Mission Hospital (with 70 surgical beds). Pathologically confirmed specimens of appendicitis were analyzed against demographic data of the patients. Data analysis was done using simple percentages, Student t or Chi-square tests and calculations were also aided with the Number Cruncher Statistical (NCSS, LLC Kaysville) software where applicable. RESULTS: During the decade, a total of 772 out of 784 cases of appendicitis recorded during the observed period were confirmed histologically from both hospitals (56% from Hospital A and 44% from Hospital B). With a local population whose disease or specimens would most probably end up in this hospital pathology department estimated at 1,753,460 the standardized incidence rate of appendicitis was 3.85 per 100,000 per annum. Fifty-two percent were males and 48% were females. The appendicitis cases were made up 0.94%, 1.53%, and 2.86% of the total hospital admissions in 2006, 2007, and 2010, respectively. There has been an increasing incidence in both sexes almost in a similar pattern. The overall mean age was 28.64 years (M 28.94 and F 28.43 years) with 6% below the age of ten and 1.5% above 60 years. The highest incidence in males and females occurred in the second and third decades, respectively. Incidences were higher during the rainy season (April to September) 68%, P < 0.05), with peaks from June to August, when 42.5% of all cases presented. CONCLUSION: Appendicitis is very uncommon in northwest Cameroon. The increasing incidence of the disease in both sexes in this region may be due to the change to a Western lifestyle. The age distribution has a similar pattern in both sexes and 85% are 40 years or less, although the incidence is marginally higher in males. Higher prevalence of infections and allergens from pollens in the rainy season could contribute to a higher incidence of appendicitis.