The epidemiology of lymphatic filariasis in Ghana, explained by the possible existence of two strains of Wuchereria bancrofti.
BACKGROUND
Lymphatic filariasis is a debilitating disease caused by the filarial worm Wuchereria bancrofti. It is earmarked for elimination by the year 2020 through the Global Program for the Elimination of LF (GPELF). In Ghana, mass treatment has been on-going since the year 2000. Earlier studies have revealed differing epidemiology of LF in the North and South of Ghana. This study was therefore aimed at understanding the possible impacts of W. bancrofti diversity on the epidemiology and control of LF in Ghana.


METHODS
The Mitochondrial, Cytochrome C Oxidase I gene of W. bancrofti samples was sequenced and analyzed. The test sequences were grouped into infrapopulations, and pairwise differences (π) and mutation rates (θ) were computed. The amount of variance within and among populations was also computed using the AMOVA. The evolutionary history was inferred using the Maximum Parsimony method.


RESULTS
Seven samples from the South and 15 samples from the North were sequenced, and submitted to GenBank with accession numbers GQ479497- GQ479518. The results revealed higher mutation frequencies in the southern population, compared to the northern population. Haplotype analyses revealed a total of 11 haplotypes (Hap) in all the 22 DNA sequences, with high genetic variation and polymorphisms within the southern samples.


CONCLUSIONS
This study showed that there is considerable genetic variability within W. bancrofti populations in Ghana, differences that might explain the observed epidemiology of LF. Further studies are however required for an in-depth understanding of LF epidemiology and control.
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Dziedzom Komi
DK
de Souza
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Jewelna
J
Osei-Poku
Yale College, Yale University, New Haven, Connecticut, 06510, USA.
Julia
J
Blum
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Helena
H
Baidoo
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Charles Addoquaye
CA
Brown
Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Bernard Walter
BW
Lawson
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Michael David
MD
Wilson
Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool-UK.
Moses John
MJ
Bockarie
Parasitology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon-Ghana.
Daniel Adjei
DA
Boakye
D000818:Animals; D000852:Anopheles / Q000469:parasitology; D004605:Elephantiasis, Filarial / Q000453:epidemiology* / Q000469:parasitology* / Q000635:transmission; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D007303:Insect Vectors; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011110:Polymorphism, Genetic; D015995:Prevalence; D014958:Wuchereria bancrofti / Q000235:genetics*
Ghana; Lymphatic Filariasis; Wuchereria bancrofti; genetic diversity