Biology subjects

Opoku, M.

Publications and source records attributed to Opoku, M..

4 recordsLinked to original sources

bioRxiv2023

Identification and characterisation of Mansonella perstans in the Volta Region of Ghana

Mansonella spp. have been reported to have a wide global distribution. Despite the distribution and occurrence with other filarial parasites like Wuchereria bancrofti, Onchocerca volvulus and Lao loa, it is given little attention. Hence, there is no surveillance programme for assessing the distribution or mansonellosis, with mild to no symptoms experienced by infected people. However, addressing this infection is critical to the onchocerciasis control program as current rapid diagnostic tools targeting O. volvulus have the tendency to cross react with Mansonella species. In this study we identified and characterised M. perstans from five sites in the Volta region of Ghana and compared them to samples from other regions. Night blood smears and filter blood blots were obtained from individuals as part of a study on lymphatic filariasis. The giemsa stained smears were screened by microscopy for the presence of filarial parasites. Genomic DNA was extracted from blood blots from 39 individuals that were positive for M. perstans and Nested PCR targeting the internal spacer 1 (ITS-1) was conducted. Of these, 30 were sequenced and 24 sequences were kept for further analysis. Phylogenetic analysis of 194 nucleotide positions showed no differences in the samples collected. Samples from Ghana clustered with samples from other reference sequences from Africa and Brazil, possibly supporting the introduction of M. perstans from sub-Saharan Africa, during the trans-Atlantic slave trade. This study draws further attention to a neglected infection and presents the first characterisation of M. perstans in Ghana and calls for more population-based studies across different geographical zones to ascertain species variations and disease distribution.

molecular biology↗

bioRxiv2023

Estimating the number of breeders from helminth larvae with genomic data.

Effective control of helminth infections requires the application of mathematical models to inform control efforts and policy, the development of product profiles for new drugs, and the monitoring of existing drugs for resistance. Key to the success of these approaches is accurately estimating the number of worms within a host, as well as distinguishing, in drug efficacy trials and monitoring, between adults surviving treatment and adults who have reinfected a host following drug treatment. In practice, observing adult worms is often extremely challenging in a patient, as many adult helminths are embedded deep in host tissues. Genetic approaches to infer kinship between larvae or eggs offer a solution to establish adult worm burdens, and to distinguish between treatment failure or treatment success followed by reinfection. Here, we use low-coverage whole-genome, and mitochondrial sequencing, of Onchocerca volvulus larvae to estimate the number of adults contributing to pools of offspring of known and unknown parentage. lcWGS reconstructs full-sibling relationships, resolving the number of unique adult worms contributing to a pool of offspring. Mitochondrial genotyping reconstructs maternal sib-ship, thus estimating the minimum number of adult females within a patient. Further development will improve these techniques for evaluating adult worm burden and trial outcome.

genomics↗

bioRxiv2022

Transmission risk assessment of Aedes-borne arboviral diseases in Accra, Ghana

BackgroundDengue, Zika and Chikungunya are Aedes-borne viral diseases that have risen to become great global health concerns in the past years. Several countries in Africa have reported outbreaks of these diseases and despite Ghana sharing borders with some of such countries, it remains free of these outbreaks. Recent studies in Ghana have revealed that there are antibodies and viral RNA of the Dengue virus serotype-2 among individuals in some localities in the Greater Accra Region. This is an indication of a possible silent transmission ongoing in the population, hence the need to assess the risk of transmission of these viruses within the country. This cross-sectional study, therefore, assessed the risk of transmission of Dengue, Zika and Chikungunya viruses in a domestic/peri-domestic (Madina) and a forest (Achimota Forest) population in the Greater Accra Region, Ghana. Methodology/FindingsAll stages of the Aedes mosquito (egg, larvae, pupae and adults) were collected around homes and in the forest area for estimation of risk indices. All eggs and immature stages were reared to adults and morphologically identified. The predominant species of Aedes mosquitoes identified from both sites were Aedes aegypti (98 % in Madina and 98.1% in Achimota forest). Aedes albopictus, an important arbovirus vector, was identified only in Madina at a prevalence of 1.5% but Achimota forest had the higher species diversity. Both study sites recorded high risk indices; Madina: Positive Ovitrap Index = 26.6%, Container Index = 36.8%, House Index = 19.8%, Breteau Index = 70.4%; Achimota: Positive Ovitrap Index = 34.2% and Container Index = 67.9%. RT-PCR to detect the presence of Dengue, Chikungunya and Zika viruses was negative for all pools tested. ConclusionAll entomological risk indicators estimated showed that both sites had a high potential of an outbreak of arboviral diseases following the introduction of these viruses. Author SummaryThe detection of antibodies and viral RNA of the dengue virus serotype 2 in some communities in the urban city of Accra, suggested the possibility of silent transmission of arboviral disease within the city. We assessed the risk of arboviral disease transmission using entomological risk indices. The study was a cross-sectional study conducted in a forest and peri domestic setting located in the southern urban city of Accra. The different stages of the Aedes mosquito were collected and, houses and containers positive for Aedes mosquitoes were also noted. The Breteau (BI), House (HI), Container (CI) and Positive ovitrap (POI) indices were determined. Real Time-PCR was conducted to determine the presence of Dengue, Zika and Chikungunya viruses in the larvae and adults collected. Aedes aegypti was the most common species identified from both sites. Aedes albopictus another competent arbovirus vector was identified in the peri-domestic site. Almost all risk indices recorded for both sites were higher than the WHO thresholds allowed for these indices. However, real time-PCR to detect the presence of Dengue, Chikungunya and Zika viruses was negative. The high entomological risk indicators estimated showed that both sites had a great potential of an outbreak following the introduction of these viruses, and a well-structured surveillance for these vectors is highly recommended. The detection of the presence of Ae. albopictus, an invasive species is also of great concern.

ecology↗

bioRxiv2021

Does Food Insecurity exist among Farm households? Evidence from Ghana

Household food security exists when households have physical, social and economic access to sufficient, safe and nutritious food at all times that meets their dietary needs and food preferences for an active and healthy life. Food security remains a serious challenge for many households in Ghana and the situation is even more prevalent among smallholder farmers. Using data collected from 2,603 farm households across Ghana and employing an ordered probit model the determinants of food security among farm households were assessed. The food security indicator-Food Consumption Score (FCS) which combines diet diversity, frequency of consumption and relative nutritional importance of different food groups was used for the analysis. Results indicated that farm households (76%) across Ghana were within the acceptable household food consumption groups. Nonetheless, 19% and 6% of farm households respectively were within the borderline and poor food consumption groups respectively. Further analysis revealed the determinants of food security to include experience, gender, improved variety adoption, access to credit and location. The suggestion is that government and private institutions should create an enabling environment to enhancing production capacities, economic and social resilience to improve on food security and nutrition.

scientific communication and education↗