Browsing by Author "de Souza, D."
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Environmental Factors Associated with the Distribution of Anopheles gambiae s.s in Ghana; an Important Vector of Lymphatic Filariasis and Malaria(PLoS ONE, 2010) de Souza, D.; Kelly-Hope, L.; Lawson, B.; Wilson, M.; Boakye, D.Anopheles gambiae s.s mosquitoes are important vectors of lymphatic filariasis (LF) and malaria in Ghana. To better understand their ecological aspects and influence on disease transmission, we examined the spatial distribution of the An. gambiae (M and S) molecular forms and associated environmental factors, and determined their relationship with disease prevalence. Published and current data available on the An. gambiae species in Ghana were collected in a database for analysis, and the study sites were georeferenced and mapped. Using the An. gambiae s.s sites, environmental data were derived from climate, vegetation and remote-sensed satellite sources, and disease prevalence data from existing LF and malaria maps in the literature. The data showed that An. gambiae M and S forms were sympatric in most locations. However, the S form predominated in the central region, while the Mformpredominated in the northern and coastal savanna regions. Bivariate and multiple regression analyses identified temperature as a key factor distinguishing their distributions. An. gambiae M was significantly correlated with LF, and 2.5 to 3 times more prevalent in the high LF zone than low to medium zones. There were no significant associations between high prevalence An. gambiae s.s locations and malaria. The distribution of the An. Gambiae M and S forms and the diseases they transmit in Ghana appear to be distinct, driven by different environmental factors. This study provides useful baseline information for disease control, and future work on the An. gambiae s.s in Ghana.Item Evidence-Based approach to decision making: the inclusion of GIS as part of Ghana's health information systems(Ghana Medical Journal, 2009) de Souza, D.At the Global Ministerial Forum on Research for Health held in Bamako, Mali, 17-19 November 2008, ministers from 59 countries adopted a call to action on research for health. One of the adopted measures was “To harness the potential of research by drawing on new sciences, emerging technologies and social and technological innovations to address priority health challenges”. Indeed, in the attempt to address health problems and prioritization of health services and resource allocation, there is the need for health information systems to support the decision-making process. One such system and technology draws on the importance of geographic location in health and disease, which is strongly emphasized by the classic public health triad of man, agent and environment. Interactions within this triad can change with time, allowing geography to play a major role in understanding the dynamics of health, and the causes and spread of disease.Item In-vitro susceptibility of mycobacterium ulceran to herbal preparations(Internet Journal of Tropical Medicine 4(2): www.ispub.com, 2008) Addo, P.; Quartey, M.; Abbas, M.; Adu-Addai, B.; Owusu, E.; Okang, I.; Dodoo, A.; de Souza, D.; Ankrah; Nii-Ayi; Ofori-Adjei, D.Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans. Surgery is the main treatment option because antibiotics have mostly been ineffective. However, there are reports of successful treatment with undisclosed herbal preparations. This study screened 44 herbal preparations for (i) inhibitory activity against 7 M. ulcerans isolates, (ii) determined the minimum inhibitory concentrations (MICs) of 10 herbal preparations and (iii) screened them for extended antimicrobial activity, since BU is often associated with secondary bacterial infections. Twenty-five of the herbal preparations inhibited the growth of the M. ulcerans isolates. MICs of the 10 herbal preparations were between 0.20 and 12.50% volume/volume (1:128 - 1:2), and all 10 demonstrated extended antimicrobial activity. The findings (i) indirectly confirmed the claims that BU is being successfully treated with herbal preparations and (ii) suggest that the treatment of BU with herbal preparations might simultaneously treat secondary bacterial and fungal infections. In conclusion, there are a number of herbal preparations with anti-M. ulcerans activity, therefore there is the need to pay more attention to herbal therapy as a potential BU treatment option.Item Low transmission of Wuchereria bancrofti in cross-border districts of Coˆte d’Ivoire: A great step towards lymphatic filariasis elimination in West Africa(Plos One, 2020-04-13) Opoku, M.; Yokoly, F.N.; Zahouli, J.B.Z.; Méite, A.; Kouassi, B.L.; de Souza, D.; Bockarie, M.; Koudou, B.G.Background Lymphatic filariasis (LF) is widely endemic in Côte d’Ivoire, and elimination as public health problem (EPHP) is based on annual mass drug administration (MDA) using ivermectin and albendazole. To guide EPHP efforts, we evaluated Wuchereria bancrofti infection indices among humans, and mosquito vectors after four rounds of MDA in four cross-border health districts of Côte d’Ivoire. Methodology We monitored people and mosquitoes for W. bancrofti infections in the cross-border health districts of Aboisso, Bloléquin, Odienné and Ouangolodougou, Côte d’Ivoire. W. bancrofti circulating filarial antigen (CFA) was identified using filariasis test strips, and antigen-positive individuals were screened for microfilaremia. Moreover, filarial mosquito vectors were sampled using window exit traps and pyrethrum sprays, and identified morphologically at species level. Anopheles gambiae s.l. and Culex quinquefasciatus females were analyzed for W. bancrofti infection using polymerase chain reaction (PCR) technique. Principal findings Overall, we found a substantial decline in W. bancrofti infection indices after four rounds of MDA compared to pre-MDA baseline data. CFA prevalence fell from 3.38–5.50% during pre-MDA to 0.00–1.53% after MDA interventions. No subjects had detectable levels of CFA in Ouangolodougou. Moreover, post-MDA CFA prevalence was very low, and below the 1% elimination threshold in Aboisso (0.19%) and Odienné (0.49%). Conversely, CFA prevalence remained above 1% in Bloléquin (1.53%). W. bancrofti microfilariae (Mf) were not found in Aboisso, Bloléquin, and Ouangolodougou, except for Odienné with low prevalence (0.16%; n = 613) and microfilaremia of 32.0 Mf/mL. No An. gambiae s.l. and Cx. quinquefasciatus pools were infected with W. bancrofti in Bloléquin and Ouangolodougou, while they exhibited low infection rates in Aboisso (1% and 0.07%), and Odienné (0.08% and 0.08%), respectively. Conclusions In cross-border areas of Côte d’Ivoire, LF infection indices in humans and mosquito vectors substantially declined after four rounds of MDA. CFA prevalence fell under the World Health Organization (WHO)-established threshold (1%) in Aboisso, Ouangolodougou and Odienné. Moreover, W. bancrofti prevalence in mosquitoes was lower than WHO-established threshold (2%) in all areas. This might suggest the interruption of W. bancrofti transmission, and possible MDA cessation. However, a formal transmission assessment survey (TAS) and molecular xenomonitoring in mosquito vectors should be implemented before eventual MDA cessation. However, MDA should pursue in Bloléquin where W. bancrofti infection prevalence remained above 1%. Our results provided important ramifications for LF control efforts towards EPHP in Côte d’Ivoire.