Background Anopheles vectors of malaria are supposedly less common in urban areas as a result of pollution, but there is increasing evidence of their adaptation to organically polluted water bodies. This study characterized the breeding habitats of Anopheles mosquitoes in the two major urban areas in southern Ghana; Accra (AMA) and Sekondi-Takoradi (STMA) Metropolitan Areas, during dry and wet seasons.Methods Anopheles mosquito larvae were sampled using standard dipping methods to determine larval densities. The origin, nature and stability of 21 randomly selected sites were observed and recorded. Mosquito larvae were reared to adults and Anopheles species identified by both morphological and molecular means.ResultsSixty-six percent of Anopheles habitats were permanent and 34% temporal, and 74.5% man-made while 25.5% were natural. Puddles and urban farm sites accounted for over 51% of all Anopheles mosquitoes sampled. The mean larval densities among the habitat types was highest of 13.7/dip for puddles and lowest of 2.3/dip for stream/river, and the variation between densities were significant (P = 0.002). The mean larval densities were significantly higher in the wet season than in the dry season for the two study areas combined (P = 0.0191) and AMA (P = 0.0228). Over 99% of the 5,802 morphologically identified Anopheles species were An. gambiae (s.l.) of which more than 99% of the studied 898 were An. coluzzii (62%) and An. gambiae (s.s.) (34%). Urban farms, puddles, swamps and ditches/ dugouts accounted for approximately 70% of all An. coluzzii identified. Conversely, drains, construction sites, streams/rivers and “others” contributed 80% of all An. gambiae (s.s.) sampled. The wet season had significantly higher proportion of Anopheles larvae compared to the dry season (Z = 8.3683, P < 0.0001). Also, the proportion of Anopheles mosquitoes produced by permanent breeding sites was 61.3% and that of temporary sites was 38.7%.ConclusionTaken together, the data suggest that man-made and/ or permanent habitats were the main contributors to Anopheles larval populations in the cities and that regulation of the anthropogenic processes that lead to development of breeding places and proper environmental management can drastically reduce mosquito breeding sites in urban areas of Ghana.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1941-3) contains supplementary material, which is available to authorized users.

Pesticide use in modern day agriculture has increased tremendously. Pesticides are used to control pests and weeds, as well as protect crops from postharvest losses; however, their effects on humans and the environment cannot be overstated. This study examined pesticide acquisition, handling, and use among 120 farmers within the catchment of a small urban irrigation scheme. Also, in-depth interviews and focus group discussions were conducted among selected farmers through which further data was collected to augment that of the survey. Twelve types of pesticides, including herbicides, insecticides, and fungicides, were found in use in the study areas. Three main sources of information about pesticides were identified, 43.3% from extension officers, 39.2% from agrochemical dealers, and 10% from colleague farmers. Seventy-five percent (75%) of the respondents purchased the pesticides from agrochemical shops. Out of 74 farmers who were observed spraying pesticides on their farms, only 25.7% wore dresses that covered their whole body but without goggles. About sixty-seven percent (66.7%) of the farmers whose chemical got finished left the containers on their farms or threw them into the bushes around. The frequency of application was influenced by affordability and size of farm, among others. The study recommended that training of farmers on pesticide handling and use should be intensified.

BackgroundPlasmodium falciparum delayed clearance with the use of artemisinin-based combination therapy (ACTs) has been reported in some African countries. Single nucleotide polymorphisms (SNPs) in two genes, P. falciparum adaptor protein complex 2 mu subunit (pfap2mu) and ubiquitin specific protease 1 (pfubp1), have been linked to delayed clearance with ACT use in Kenya and recurrent imported malaria in Britain. With over 12 years of ACT use in Ghana, this study investigated the prevalence of SNPs in the pfap2mu and pfubp1 in Ghanaian clinical P. falciparum isolates to provide baseline data for antimalarial drug resistance surveillance in the country.MethodsFilter paper blood blots collected in 2015–2016 from children aged below 9 years presenting with uncomplicated malaria at hospitals in three sentinel sites Begoro, Cape Coast and Navrongo were used. Parasite DNA was extracted from 120 samples followed by nested polymerase chain reaction (nPCR). Sanger sequencing was performed to detect and identify SNPs in pfap2mu and pfubp1 genes.ResultsIn all, 11.1% (9/81) of the isolates carried the wildtype genotypes for both genes. A total of 164 pfap2mu mutations were detected in 67 isolates whilst 271 pfubp1 mutations were observed in 72 isolates. The majority of the mutations were non-synonymous (NS): 78% (128/164) for pfap2mu and 92.3% (250/271) for pfubp1. Five unique samples had a total of 215 pfap2mu SNPs, ranging between 15 and 63 SNPs per sample. Genotypes reportedly associated with ART resistance detected in this study included pfap2mu S160N (7.4%, 6/81) and pfubp1 E1528D (7.4%, 6/81) as well as D1525E (4.9%, 4/81). There was no significant difference in the prevalence of the SNPs between the three ecologically distinct study sites (pfap2mu: χ2 = 6.905, df = 2, P = 0.546; pfubp1: χ2 = 4.883, df = 2, P = 0.769).ConclusionsThe detection of pfap2mu and pfubp1 genotypes associated with ACT delayed parasite clearance is evidence of gradual nascent emergence of resistance in Ghana. The results will serve as baseline data for surveillance and the selection of the genotypes with drug pressure over time. The pfap2mu S160N, pfubp1 E1528D and D1525E must be monitored in Ghanaian isolates in ACT susceptibility studies, especially when cure rates of ACTs, particularly AL, is less than 100%.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-2762-3) contains supplementary material, which is available to authorized users.

Introduction Schistosomes (blood flukes) are digenetic trematodes of the super family Schistosomatoidea. They cause the disease schistosomiasis, which is commonly called bilharziasis. The parasites undergo part of their developmental phase into infective forms in water borne planorbid snails. Hence, schistosomiasis is a helminthic water-borne disease. Five species of Schistosoma have been found to be pathogenic parasites of man (Ross et al., 2007; Gryseels et al., 2006). These are; Schistosoma haemato-bium, causing urinary schistosomiasis, S. mansoni, S. japonicum, S. mekongi and S. intercalatum, all causing intestinal schistosomiasis. Human schistosomiasis remains one of the most important parasitic diseases in the tropics for which there are yet to be vaccines. About 200 million people are estimated to be infected and 500-600 million more exposed to infection (Webbe, 1981) and about 131 million infected in Sub-Saharan Africa alone. The disease is endemic in Ghana and its public health importance was reported by McCullough (1954), who noted then that approximately 20% of the total population of

Background: The interplay between Epstein-Barr virus infection, malaria, and endemic Burkitt’s Lymphoma is not well understood. Reports show diminished EBV-specific Th1 responses in children living in malaria endemic areas and deficiency of EBNA1-specific IFN-γ T cell responses in children with endemic Burkitt’s Lymphoma (eBL). This study, therefore, examined some factors involved in the loss of EBNA-1-specific T cell responses in eBL. Methods: T-cell subset frequencies, activation, and IFN-γ- or IL-4-specific responses were analyzed by flow-cytometry. Plasma cytokine levels were measured by ELISA. Results: CD4+ and CD8+ cells in age- and sex-matched healthy controls (n = 3) expressed more IFN-γ in response to all immunostimulants than in pediatric endemic BL (eBL) patients (n = 4). In healthy controls, IFN-γ expression was higher than IL-4 expression, whereas in eBL patients the expression of IL-4 by CD4+ cells to EBNA-1 was slightly higher than IFN-γ. Moreover, the blood levels of TNF-α was significantly lower (p = 0.004) while IL-10 was significantly higher (p = 0.038), in eBL patients (n = 21) compared to controls (n = 16). Additionally, the frequency of CD4+CD25hi+ T cells was higher in both age-matched acute uncomplicated malaria (n = 26) and eBL (n = 14) patients compared to healthy controls (n = 19; p = 0.000 and p = 0.027, respectively). Conclusion: The data suggest that reduced Th1 response in eBL might be due to increased levels of IL-10 and T reg cells.

BackgroundThe overlap in geographical distribution of Plasmodium falciparum malaria and endemic Burkitt's lymphoma (eBL) – an aggressive Epstein-Barr virus (EBV)-associated B-cell tumour occurring almost exclusively in the tropics – strongly suggests a link between the two diseases. It is suspected that the polyclonal B-cell activation in P. falciparum malaria may precipitate a breakdown in homeostatic T-cell control of EBV-immortalized B-cell proliferation. Previous studies have suggested that a particular T-cell subset, characterized by expression of Vδ1+ γδ T-cell receptors, is important for maintaining B-cell homeostasis, both in P. falciparum- exposed populations and in individuals subject to polyclonal B-cell activation of other aetiology. The objective of the present study was, therefore, to characterize lymphocyte phenotypes and to investigate possible differences in T-cell subset composition and activation status in P. falciparum-exposed Ghanaian children with and without eBL.MethodsVenous blood samples in heparin from 21 eBL patients (mean age: 7.0 years; range: 3–11 years), referred to the Burkitt's Tumour Centre at Korle-Bu Teaching Hospital, Accra and 15 healthy, age and sex matched children, were stained with fluorescein isothiocyanate (FITC)-, phycoerythrin (PE)-, R-phycoerythrin (RPE)- and RPE-Cy5-conjugated antibodies (CD3, CD4, CD8, CD25, CD69, CD95, HLA-DR, TCR-γδ, Vδ1, Vδ3, Vγ9 and B-cells) and acquired on a flow cytometer.ResultsA reduction in the proportion of CD3+ cells in eBL patients, due mainly to perturbations among TCR-γδ+ cells was observed. In contrast, the proportions of CD4+ or CD8+ cells were relatively unaffected, as were the mean numbers of peripheral blood mononuclear cells.ConclusionSelective changes in numbers and activation status of TCR-γδ+ cells occurs in Ghanaian children with eBL, a pattern which is similar to P. falciparum-induced changes. The data supports the hypothesis of a regulatory role for Vδ1+ TcR-γδ T-cells in maintaining B-cell homeostasis and provides insights into the pathogenesis of eBL.

Malaria pathogenesis may be influenced by IgE responses and cytokine cross-regulation. Several mutations in the IL-4/STAT6 signaling pathway can alter cytokine cross-regulation and IgE responses during a Plasmodium falciparum malarial infection. This study investigated the relationship between a STAT6 intronic single-nucleotide polymorphism (rs3024974), total IgE, cytokines, and malaria severity in 238 Ghanaian children aged between 0.5 and 13 years. Total IgE and cytokine levels were measured by ELISA, while genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP). Compared with healthy controls, heterozygosity protected against clinical malaria: uncomplicated malaria (odds ratios [OR] = 0.13, P < 0.001), severe malarial anemia (OR = 0.18, P < 0.001), and cerebral malaria (OR = 0.39, P = 0.022). Levels of total IgE significantly differed among malaria phenotypes (P = 0.044) and rs3024974 genotypes (P = 0.037). Neither cytokine levels nor IL-6/IL-10 ratios were associated with malaria phenotypes or rs3024974 genotypes. This study suggests a role for rs3024974 in malaria pathogenesis and offers further insights into an IL-4/STAT6 pathway mutation in malaria pathogenesis.

This study evaluates the extent to which urban residents of Accra and Sekondi-Takoradi (all of southern Ghana) were aware of environment and climate-related variability. A total of 150 questionnaires were given to adults of 40 years and above who lived in the cities for at least 35 years. SPSS version 16 was used to process the data. Results show that all respondents in Accra Metropolitan Area (AMA) and 96% of them in Sekondi-Takoradi Metropolitan Area (STMA) noted the deteriorating vegetation cover over the cities. Similarly, 93% and 83% of them in AMA and STMA, respectively, observed that land use pattern of the two cities has changed considerably. There was positive and statistically significant correlation between respondents' educational attainment and their awareness of changes in land use/land cover (r = 0.18, n = 140, p = 0.03). Also, 71% in AMA and 89% in STMA stated that temperature of the cities had been increasing over the years. In all, 82.9% of the respondents mentioned that they had problem with the increasing population of mosquitoes. Respondents demonstrated ample knowledge of environment and climate variability and should be engaged in preventing further environmental degradation. The top-down approach to environmental issues has failed; the bottom-up approach to environmental maintenance is needed.