Detection of DNA of filariae closely related to Mansonella perstans in faecal samples from wild non-human primates from Cameroon and Gabon.

BACKGROUND: The Onchocercidae is a family of filarial nematodes with several species of medical or veterinary importance. Microfilariae are found in the blood and/or the dermis and are usually diagnosed in humans by microscopy examination of a blood sample or skin biopsy. The main objectives of this study were to evaluate whether filariae DNA can be detected in faecal samples of wild non-human primates (NHPs), whether the detected parasites were closely related to those infecting humans and whether filarial DNA detection in faeces is associated with co-infections with nematodes (Oesophagostumum sp. and Necator sp.) known to cause blood loss while feeding on the host intestinal mucosa. METHODS: A total of 315 faecal samples from 6 species of NHPs from Cameroon and Gabon were analysed. PCRs targeted DNA fragments of cox1 and 12S rDNA genes, to detect the presence of filariae, and the internal transcribed spacer 2 (ITS2), to detect the presence of Oesophagostomum sp. and Necator sp. infections. RESULTS: Among the 315 samples analysed, 121 produced sequences with > 90% homology with Onchocercidae reference sequences. However, 63% of the 12S rDNA and 78% of the cox1 gene sequences were exploitable for phylogenetic analyses and the amplification of the 12S rDNA gene showed less discriminating power than the amplification of the cox1 fragment. Phylogenetic analyses showed that the cox1 sequences obtained from five chimpanzee DNA faecal samples from Gabon and two from Cameroon cluster together with Mansonella perstans with high bootstrap support. Most of the remaining sequences clustered together within the genus Mansonella, but the species could not be resolved. Among the NHP species investigated, a significant association between filarial DNA detection and Oesophagostomum sp. and Necator sp. infection was observed only in gorillas. CONCLUSIONS: To our knowledge, this is the first study reporting DNA from Mansonella spp. in faecal samples. Our results raise questions about the diversity and abundance of these parasites in wildlife, their role as sylvatic reservoirs and their potential for zoonotic transmission. Future studies should focus on detecting variants circulating in both human and NHPs, and improve the molecular information to resolve or support taxonomy classification based on morphological descriptions.

Humans and great apes cohabiting the forest ecosystem in central african republic harbour the same hookworms.

BACKGROUND: Hookworms are important pathogens of humans. To date, Necator americanus is the sole, known species of the genus Necator infecting humans. In contrast, several Necator species have been described in African great apes and other primates. It has not yet been determined whether primate-originating Necator species are also parasitic in humans. METHODOLOGY/PRINCIPAL FINDINGS: The infective larvae of Necator spp. were developed using modified Harada-Mori filter-paper cultures from faeces of humans and great apes inhabiting Dzanga-Sangha Protected Areas, Central African Republic. The first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA and partial cytochrome c oxidase subunit 1 (cox1) gene of mtDNA obtained from the hookworm larvae were sequenced and compared. Three sequence types (I-III) were recognized in the ITS region, and 34 cox1 haplotypes represented three phylogenetic groups (A-C). The combinations determined were I-A, II-B, II-C, III-B and III-C. Combination I-A, corresponding to N. americanus, was demonstrated in humans and western lowland gorillas; II-B and II-C were observed in humans, western lowland gorillas and chimpanzees; III-B and III-C were found only in humans. Pairwise nucleotide difference in the cox1 haplotypes between the groups was more than 8%, while the difference within each group was less than 2.1%. CONCLUSIONS/SIGNIFICANCE: The distinctness of ITS sequence variants and high number of pairwise nucleotide differences among cox1 variants indicate the possible presence of several species of Necator in both humans and great apes. We conclude that Necator hookworms are shared by humans and great apes co-habiting the same tropical forest ecosystems.

Anemia severa causada por Necator americanus: reporte de un caso / Severe anemia caused by Necator americanus: case report

En climas templados, yungas (zona intermedia entre valle y trópico) y trópico, prevalecen dos parásitos hematófagos: Necator americanusy Ancylostoma duodenale, responsable de una anemia crónica, que lleva a los niños a tener niveles tan bajos de Hb, que a veces sonconsiderados incompatibles con la vida; rara vez originan sangrado agudo severo.Describimos el caso de un niño, de seis meses de edad, procedente de Coroico (Nor Yungas) con disentería inicial, misma que luego secomplica con melenas y rectorragia de sangre rutilante que origina una hipovolemia severa, rayana en el choque. Sometido a exploraciónquirúrgica por persistencia del sangrado, previo gammagrafía para descartar un divertículo de Meckel, no se halla el sitio de sangradopor lo que se realiza laparotomía exploratoria y posteriormente una endoscopía, identifi cándose en duodeno foco de sangrado originadopor parásitos, que por su morfología se asume que se trate de Necator americanus. Con este diagnóstico, recibe transfusiones para suestabilizar su hipovolemia y Mebendazol, con buena evolución, remisión del sangrado de tubo digestivo, y buena tolerancia a la alimentación.El “sangrado agudo” por uncinarias, es excepcional, hecho que justifi ca la presentación del caso y permite realizar un recordatorio breve delos mecanismos responsables de ello...

In temperate climate, yungas (intermediate zone between valley and tropical lowland), two blood sucking parasites are prevalent: Necator americanus and Ancylostoma duodenale, responsible for chronic anaemia in children that causes extremely low Hb levels sometimesconsidered as incompatible with life; only in rare cases acute bleeding occurs.We describe the case of a six months old child stemming from Coroico (Nor Yungas) initially with dysentery that becomes complicated by melaena and rectal bleeding originating severe hypovolaemia bordering on shock. After gammagraphy in order to exclude Meckel’s diverticle, the child was submitted to surgical exploration, where no source of bleeding could be found, therefore an explorative laparotomy was performed and later on an endoscopy, where the source of bleeding was identifi ed in the duodenum as caused by the parasite Necator Americanus. With this diagnose, blood transfusions were administered to the child in order to stabilize the hypovolaemia and Mebendazol was given. The evolution was good, the bleeding stopped and feeding was well tolerated.Acute bleeding caused by hook worms is exceptional; therefore we present this case as a short reminder of the responsible mechanisms.