Prevalence of Intestinal Parasitosis in Guinea: Systematic Review of the Literature and Meta-Analysis

Cryptosporidium spp. prevalence in the general population in Guinea: first large-scale screening study

Cryptosporidium is a leading cause of diarrheal mortality in children in Africa and Asia. Despite the public health significance of this parasite, its molecular epidemiology and circulation in Guinea remain poorly understood. Therefore, this study aimed to determine the prevalence and genotype distribution of Cryptosporidium in the Guinean general population. To achieve this, fecal samples were collected from 834 individuals, both with and without digestive disorders, at two hospitals in Conakry. The presence of the parasite in the stool samples was detected using nested PCR targeting the SSU rDNA gene, followed by sequencing of the PCR products for genotyping of the isolates. The PCR-based prevalence was 0.12% for the whole cohort, and 0.2% among adults. The low frequency of Cryptosporidium observed in the current study is thus consistent with the prevalence of this parasite already reported in certain other African countries. The species identified in the positive samples was Cryptosporidium hominis. This study is the first to report the prevalence of Cryptosporidium in the general population of Guinea. Given the potential of this parasite to cause life-threatening diarrhea, further studies are needed to clarify the epidemiology of Cryptosporidium in this country.

Influence of tides on the dissemination and related health risks of intestinal helminths along the Kribi beaches (Atlantic Coast, Southern Cameroon)

Kribi is a seaside town that welcomes thousands of tourists each year. However, the poor sanitation condition of its beaches along the Atlantic coast is not without risk for visitors. In this study, we used the formol-ether concentration technique to identify and quantify larvae or eggs of intestinal helminths in waters of three regularly visited Kribi beaches (Mpalla, Ngoyè, and Mboamanga). Results revealed that all identified larvae and eggs were cestodes (Hymenolepis nana) and nematodes (Strongyloides sp., Ascaris sp., Ancylostoma duodenale and Trichuris trichiura). All the helminth eggs and larvae showed high abundance at low tide during rainy seasons. Ancylostoma duodenale eggs, totally absent at Mpalla, were densely present at low tide at Ngoyè (301 ± 15 eggs/L). Trichuris trichiura eggs showed the lowest abundance (0 to 62 eggs/L) at all sites. Abiotic variables indicated that waters at the various beaches were basic (pH: 8.75-9.77), generally warmer (32.44°C at Mpalla in the Short Rainy Season), more oxygenated at low tide, and moderately mineralized at high tide. Positive and significant correlations were observed at Ngoyè at low tide between Strongyloides sp. larvae and dissolved oxygen (P ˂ 0.05); and between Ancylostoma duodenale eggs and temperature (P ˂ 0.05). The overall results indicated that the beaches studied are subjected to fecal pollution. This pollution is more accentuated during low tides than during high tides. Depending on tidal movements, swimmers risk exposure to helminth eggs and larvae known to be responsible for gastroenteritis.