Journal of
Parasitology and Vector Biology

  • Abbreviation: J. Parasitol. Vector Biol.
  • Language: English
  • ISSN: 2141-2510
  • DOI: 10.5897/JPVB
  • Start Year: 2009
  • Published Articles: 179

Full Length Research Paper

Prevalence of Loa loa and Mansonella perstans detection in urban areas of Southeast Gabon

Eyang-Assengone Elsa Rush
  • Eyang-Assengone Elsa Rush
  • Department of Tropical Infectiology, Ecole Doctorale Régionaled’ Afrique Centrale, Franceville, Gabon.
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Roland Dieki
  • Roland Dieki
  • Department of Parasitology, Interdisciplinary Center for Medical Research of Franceville, Franceville, Gabon.
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Mvoula Odile Ngounga
  • Mvoula Odile Ngounga
  • Department of Health, Ministry of National Defense, Gabon.
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Antoine Roger Mbou Moutsimbi
  • Antoine Roger Mbou Moutsimbi
  • Department of Parasitology, Interdisciplinary Center for Medical Research of Franceville, Franceville, Gabon.
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Jean Bernard Lekana-Douki
  • Jean Bernard Lekana-Douki
  • Department of Parasitology, Interdisciplinary Center for Medical Research of Franceville, Franceville, Gabon.
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Jean Paul Akue
  • Jean Paul Akue
  • Department of Parasitology, Interdisciplinary Center for Medical Research of Franceville, Franceville, Gabon.
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  •  Received: 19 May 2020
  •  Accepted: 20 October 2020
  •  Published: 30 November 2020

Abstract

Loa loa and Mansonella perstans are two filarial species commonly found in Gabon loiasis has gained attention because of severe adverse events occurring in individuals harboring very high L. loa microfilarial loads after treatment with ivermectin. However, most studies were carried out in rural areas. This work aimed at the study of the prevalence of filarial infections in different urban areas of southeast Gabon. The cross-sectional survey was conducted between May and December 2018 in Franceville, Moanda, and Mvengue. Participants provided written informed consent, a questionnaire to collect data on demographics and related clinical signs (ocular passage of the worm, Calabar swelling, and pruritus). Blood was collected to search for filarial infections. Plasma and blood pellets were separated after centrifugation. The plasma was used for detection of specific IgG4 by ELISA. In total, 545 were samples collected,  the overall prevalence of filarial infection in the three cities was 4.77% (95% CI: 3.06–7.97). The prevalence of L. loa infection was 4.59% (95% CI: 3.05–6.79), and 0.18% (95% CI: 0.01–1.18) for M. perstans. The prevalence of ocular passage of the worm, Calabar swelling and pruritus was 27.71% (95% CI: 24.03–31.07), 17.98% (95% CI: 17.90–24.52) and 48.99% (95% CI: 44.72–53.27), respectively. The overall prevalence of specific IgG4 producers was 15.60% (95% CI: 12.71–19.98). There was no correlation between the density of microfilaremia and ocular passage of the worm (p=0.074), but there was a correlation with Calabar swelling (p=0.0005) and between the level of IgG4 subclass and microfilaremic status (p=0.001). This study reveal that the prevalence of L. loa and Mansonella perstans was low in these urban areas, compared with that in rural areas of the same region which was 20.4% for L. loa and 10.2% for M. perstans. These results suggest a different pattern of filarial infection between rural and urban areas.

Keywords: Prevalence, Loa loa, M. perstans, urban area, specific IgG4