Fadilatou Foule Bakari, Tchami Mbagnia Mureille C, Kamwa Ngassam Romuald I, Kengne-Fokam Alvine C, Ngambia Freitas François S, Nguiffo Nguete Daniel, Nana Djeunga Hugues C, Wondji Charles S, Melachio Tanekou Tito T, Njiokou Flobert
Laboratory of Parasitology and Ecology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon.
Department of Biological Sciences, Faculty of Science, University of Maroua, Maroua, Cameroon.
PLoS Negl Trop Dis. 2025 Jun 27;19(6):e0013265. doi: 10.1371/journal.pntd.0013265. eCollection 2025 Jun.
Schistosomiasis is the world's second-most important parasitic disease affecting humans. Among the two main forms of the disease, intestinal schistosomiasis due to Schistosoma mansoni is predominant in Cameroon, where its intermediate host Biomphalaria spp. is widely distributed, particularly in the Adamawa plateau. As a prerequisite to targeted vector control for effective elimination of intestinal schistosomiasis infection, we mapped the geographical distribution of Biomphalaria snails in the Adamawa Region.
METHODOLOGY/PRINCIPAL FINDINGS: A total of 43 human-water contact sites were visited across the Adamawa Region for snail collection. Snail species were identified morphologically and with PCR-RFLP technique at the ITS2 rDNA region using the HpaII restriction enzyme. The genus Biomphalaria was identified at 13 sites (30.2%), four sites (9,3%) harboured Gyraulus species firstly identified as Biomphalaria with shell morphology, and 22 sites (51,16%) were free from any snail species. Two Biomphalaria species were identified, Biomphalaria pfeifferi in 12 water contact sites, and Biomphalaria camerunensis was found only in one site (Djalingo, Vina Division), and it was the first report of this species in the Northern Cameroon (above the 6° latitude North). Morphologic identification was supported by PCR-RFLP results and sequencing revealed three haplotypes for Biomphalaria pfeifferi and one haplotype for Biomphalaria camerunensis. The studied populations were stable according to neutrality tests (Tajima's D and Fu Fs) and no signal of gene flow was observed between them.
CONCLUSIONS/SIGNIFICANCE: This study confirmed the presence of Biomphalaria pfeifferi in the Adamawa Region and reported for the first time B. camerunensis above 6° of Latitude North, thus deserving further monitoring to assess its current distribution in Cameroon.
血吸虫病是世界上影响人类的第二大重要寄生虫病。在该疾病的两种主要形式中，由曼氏血吸虫引起的肠道血吸虫病在喀麦隆占主导地位，其中间宿主双脐螺属在该国广泛分布，尤其是在阿达马瓦高原。作为有效消除肠道血吸虫病感染的针对性病媒控制的前提条件，我们绘制了阿达马瓦地区双脐螺的地理分布图。
方法/主要发现：在阿达马瓦地区共走访了43个人与水接触的地点以收集螺类。通过形态学以及使用HpaII限制性内切酶对ITS2核糖体DNA区域进行PCR-RFLP技术来鉴定螺类物种。在13个地点（30.2%）鉴定出双脐螺属，4个地点（9.3%）有首先通过壳形态鉴定为双脐螺属的旋螺属物种，22个地点（51.16%）未发现任何螺类物种。鉴定出两种双脐螺属物种，在12个水接触地点发现了费氏双脐螺，仅在一个地点（贾林戈，维纳分区）发现了喀麦隆双脐螺，这是该物种在喀麦隆北部（北纬6度以上）的首次报告。PCR-RFLP结果支持了形态学鉴定，测序揭示了费氏双脐螺的三种单倍型和喀麦隆双脐螺的一种单倍型。根据中性检验（ Tajima's D和Fu Fs），所研究的种群是稳定的，并且未观察到它们之间的基因流动信号。
结论/意义：本研究证实了阿达马瓦地区存在费氏双脐螺，并首次报告了北纬6度以上的喀麦隆双脐螺，因此值得进一步监测以评估其在喀麦隆的当前分布情况。
