33 research outputs found
Impact of Mass Drug Administration (MDA) on the Transmission of Lymphatic Filariasis in Tono Irrigation Area in Navrongo, Ghana
Lymphatic filariasis is ranked as one of the leading causes of permanent and long-term disability and also oldest and most debilitating neglected tropical disease worldwide. Filariasis is caused by nematode endoparasitic worms transmitted to humans by various mosquito vectors. World Health Organization established Global Programme to Eliminate Lymphatic Filariasis as a public health problem by the year 2020. The strategies employed are to interrupt transmission through mass drug administration (MDA) and to alleviate suffering and disability via morbidity management; and vector control. It is expected that after implementation of the strategies above, transmission assessment surveys are required to ascertain their progress, impact and efficacies. As MDA was the main strategy, this work therefore determined impact of mass drug administration on the transmission of lymphatic filariasis in Tono Irrigation area in Navrongo following more than nine years of its implementation. Human landing and pyrethrum spray monthly collections of mosquitoes in Wuru and Saboro were dissected to determine the transmission level in the study area. The mosquitoes collected in the study comprised 90.22% (3,650) Anopheles species and 9.78% (386) Culex species with no Aedes or Mansonis species. The man biting rate computed from (Human Landing Catch) HLC was 162.25 bites/man/night in Wuru and 143.75bites/man/night in Saboro. Only 3An. species were infected with filarial parasites; 2 in Saboro with 2mf, and 1L2 in a mosquito in Wuru. However, there was no L3 stage recorded in any of the 3,560 mosquitoes macerated implying that there was no ongoing transmission of LF in the study sites since no infective bites were encountered. However, a follow up survey is required to assess the level of transmission since one survey is inadequate to declare the place free of LF. Keywords: Anopheles species, Wuchereria bancrofti, Mass Drug Administration, Lymphatic filariasis, Ghan
An evaluation of Wb123 antibody elisa in individuals treated with ivermectin and albendazole, and implementation challenges in Africa
The development of antibody testing for the diagnosis of lymphatic filariasis (LF) is intended to enhance the monitoring and evaluation activities of the Global Program for the Elimination of LF. This is due to the fact that antibody tests are expected to be the most sensitive at detecting exposure to LF compared to antigen that takes longer to develop. To this end a new antibody-based enzyme linked immunosorbent assay (ELISA) to Wuchereria bancrofti antigen Wb123 has been developed and further designed into a point of care rapid diagnostic test, under evaluation. In pretreatment surveys, individuals were tested for antigen using the immuno-chromatographic test (ICT) card, and night blood microfilariae, after which all positives were treated using Ivermectin and Albendazole. The Wb123 ELISA was tested in antigen positive individuals, three months after they were treated. Samples were also tested for ICT and night blood microfilariae. The results revealed a reduction in microfilariae and ICT prevalence after treatment. Antigen and antibody prevalence increased with age. However, there was no correlation with the antibody responses observed. The mean WB123 antibody titers were higher among ICT positives, but not significantly different from ICT negative persons. While the Wb123 is targeted for use in untreated populations, further evaluations and guidelines will be required to define its use in populations that have undergone treatment for the control of LF.Keywords: Lymphatic filariasis, elephantiasis, antigen, antibody, Wb123, Ghan
The epidemiology of lymphatic filariasis in Ghana, explained by the possible existence of two strains of Wuchereria bancrofti
Introduction
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.
Conclusion
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
Medicinal Plants for Treatment of Prevalent Diseases
This chapter focuses on reviewing publications on medicinal plants used in the treatment of common diseases such as malaria, cholera, pneumonia, tuberculosis and asthma. Traditional medicine is still recognized as the preferred primary health care system in many rural communities, due to a number of reasons including affordability and effectiveness. The review concentrated on current literature on medicinal plants, highlighting on information about ethnobotany, phytochemistry and pharmacology. The search for publications on medicinal plants with scientifically proven efficacy was carried out using electronic databases such as Science Direct, Google Scholar, SciFinder and PubMed. In all, about 46 species of different families with potent biological and pharmacological activities were reviewed. All the plants reviewed exhibited potent activity confirming their various traditional uses and their ability to treat prevalent diseases
Onchocerciasis Control: Vision for the Future from a Ghanian perspective
Since 1987 onchocerciasis control has relied on the donation of ivermectin (Mectizan®, Merck & Co., Inc.) through the Mectizan Donation Programme. Recently, concern has been raised over the appearance of suboptimal responses to ivermectin in Ghana – highlighting the potential threat of the development of resistance to ivermectin. This report summarises a meeting held in Ghana to set the research agenda for future onchocerciasis control. The aim of this workshop was to define the research priorities for alternative drug and treatment regimes and control strategies to treat populations with existing evidence of suboptimal responsiveness and define research priorities for future control strategies in the event of the development of widespread ivermectin resistance
Natural Products as Therapeutic Option for Echinococcossis
Until the 1980s surgery remained the only treatment option for cystic echinococcosis, a neglected tropical disease caused by infection with tapeworms of the genus Echinocococcus. Following the development of the benzmidazoles, there has been an increase in the use of chemotherapy over the years, especially as an adjunct to surgery or in the management of inoperable cysts. In spite of their usefulness, both surgery and chemotherapy are associated with significant limitations that warrants the search for or consideration of alternative treatment options such natural products. This chapter aims to discuss the scolicidal activity of different species of medicinal plants and their active metabolites in the treatment of echinococcosis. Excerpta Medica Database, Google Scholar, PubMed Central and Scopus were electronic databases used to retrieve the relevant literature. Medicinal plants used commonly and effectively against protoscoleces were Zataria multiflora, Nigella sativa, Berberis vulgaris, Zingiber officinale, and Allium sativum. Only Z. multiflora and A. sativum were shown to effective against Echinococcus granulosus protoscoleces in vivo. In addition, these natural products have not been associated with any significant adverse effect. In animal models Thus, natural products with demonstrated activity against E. granulosus may serve as alternative therapy in the management of echinococcosis
Doxycycline Leads to Sterility and Enhanced Killing of Female Onchocerca volvulus Worms in an Area With Persistent Microfilaridermia After Repeated Ivermectin Treatment: A Randomized, Placebo-Controlled, Double-Blind Trial
Background
Ivermectin (IVM) has been the drug of choice for the treatment of onchocerciasis. However, there have been reports of persistent microfilaridermia in individuals from an endemic area in Ghana after many rounds of IVM, raising concerns of suboptimal response or even the emergence of drug resistance. Because it is considered risky to continue relying only on IVM to combat this phenomenon, we assessed the effect of targeting the Onchocerca volvulus Wolbachia endosymbionts with doxycycline for these individuals with suboptimal response.
Methods
One hundred sixty-seven patients, most of them with multiple rounds of IVM, were recruited in areas with IVM suboptimal response and treated with 100 mg/day doxycycline for 6 weeks. Three and 12 months after doxycycline treatment, patients took part in standard IVM treatment.
Results
At 20 months after treatment, 80% of living female worms from the placebo group were Wolbachia positive, whereas only 5.1% in the doxycycline-treated group contained bacteria. Consistent with interruption of embryogenesis, none of the nodules removed from doxycycline-treated patients contained microfilariae, and 97% of those patients were without microfilaridermia, in contrast to placebo patients who remained at pretreatment levels (P < .001). Moreover, a significantly enhanced number of dead worms were observed after doxycycline.
Conclusions
Targeting the Wolbachia in O. volvulus is effective in clearing microfilariae in the skin of onchocerciasis patients with persistent microfilaridermia and in enhanced killing of adult worms after repeated standard IVM treatment. Strategies can now be developed that include doxycycline to control onchocerciasis in areas where infections persist despite the frequent use of IVM
Design considerations for identifying breast cancer risk factors in a population-based study in Africa:Assessing breast cancer risk factors in Africa
Recruiting population controls for case-control studies in sub-Saharan Africa:The Ghana Breast Health Study
BackgroundIn case-control studies, population controls can help ensure generalizability; however, the selection of population controls can be challenging in environments that lack population registries. We developed a population enumeration and sampling strategy to facilitate use of population controls in a breast cancer case-control study conducted in Ghana.MethodsHousehold enumeration was conducted in 110 census-defined geographic areas within Ghana’s Ashanti, Central, Eastern, and Greater Accra Regions. A pool of potential controls (women aged 18 to 74 years, never diagnosed with breast cancer) was selected from the enumeration using systematic random sampling and frequency-matched to the anticipated distributions of age and residence among cases. Multiple attempts were made to contact potential controls to assess eligibility and arrange for study participation. To increase participation, we implemented a refusal conversion protocol in which initial non-participants were re-approached after several months.Results2,528 women were sampled from the enumeration listing, 2,261 (89%) were successfully contacted, and 2,106 were enrolled (overall recruitment of 83%). 170 women were enrolled through refusal conversion. Compared with women enrolled after being first approached, refusal conversion enrollees were younger and less likely to complete the study interview in the study hospital (13% vs. 23%). The most common reasons for non-participation were lack of interest and lack of time.ConclusionsUsing household enumeration and repeated contacts, we were able to recruit population controls with a high participation rate. Our approach may provide a blue-print for others undertaking epidemiologic studies in populations that lack accessible population registries.</div