Mansonella, including a Potential New Species, as Common Parasites in Children in Gabon

Abstract

BackgroundLike other tropical African countries, Gabon is afflicted by many parasitic diseases, including filariases such as loiasis and mansonellosis. This study aimed to assess the prevalence of these two filarial diseases in febrile and afebrile children using quantitative real-time PCR and standard PCR assays coupled with sequencing.Methodology/Principal FindingsDNA from blood specimens of 1,418 Gabonese children (1,258 febrile and 160 afebrile) were analyzed. Overall, filarial DNA was detected in 95 (6.7%) children, including 67 positive for M. perstans (4.7%), which was the most common. M. perstans was detected in 61/1,258 febrile children (4.8%) and 6/160 afebrile children (3.8%, P = 0.6). Its prevalence increased statistically with age: 3.5%, 7.7% and 10.6% in children aged ≤5, 6–10 and 11–15 years, respectively. M. perstans prevalence was significantly higher in Koulamoutou and Lastourville (12% and 10.5%, respectively) than in Franceville and Fougamou (2.6% and 2.4%, respectively). Loa loa was detected in seven febrile children including one co-infection with M. perstans. Finally, 21 filarial DNA positive were negative for M. perstans and Loa loa, but ITS sequencing could be performed for 12 and allowed the identification of a potential new species of Mansonella provisionally called “DEUX”. Mansonella sp. “DEUX” was detected only in febrile children.Conclusions/SignificanceFurther study should be performed to characterize Mansonella sp. “DEUX” and evaluate the clinical significance of mansonellosis in humans.

Mansonella ozzardi mitogenome and pseudogene characterisation provides new perspectives on filarial parasite systematics and CO-1 barcoding

“…In the field of mansonellosis research tools of this type have been used to: confirm the existence of M. perstans in Latin America 11 ; invalidate the legitimacy of reports of a-typical forms of M. ozzardi parasites 8 , 30 , 37 and to reveal the existence of a previously unrecognised subspecies of M. perstans , e.g. M. perstans “deux” 38 . Existing tools have not, however, yet provided much help in understanding of the phylogeography or population genetics of filarial parasites because the sequences that have been historically targeted have uncovered so little within species diversity 2 , 3 .…”

Mansonellosis: current perspectives

“… 48 – 57 Although these mitochondrial and rDNA phylogenetic studies and more recent multilocus sequence typing challenged traditional morphology-based phylogenies of the species within the family Onchocercidae, 58 none has hitherto challenged the morphology-based genus Mansonella proposed by Eberhard and Orihel in 1984, from which the modern use of the term “mansonellosis” has arisen. 16 , 17 , 50 , 54 – 60 …”

Emerging infectious diseases in Africa in the 21st century

“…It concerns not only bacterial and viral diseases but also protozoal and helminthic ones. For instance, a new genetic variant of Mansonella associated with fever in children was recently reported from Gabon [55] . It is evident that Africa is characterized by the greatest infectious disease burden as well as by the weakest public health infrastructure in the world; further, efforts to establish public health infrastructures that are actually effective may take a period of years, even decades.…”