Time filter

Source Type

Leski T.A.,U.S. Navy | Stockelman M.G.,U.S. Navy | Moses L.M.,Tulane University | Moses L.M.,The New School | And 5 more authors.
Emerging Infectious Diseases | Year: 2015

Lassa virus (LASV) is endemic to parts of West Africa and causes highly fatal hemorrhagic fever. The multimammate rat (Mastomys natalensis) is the only known reservoir of LASV. Most human infections result from zoonotic transmission. The very diverse LASV genome has 4 major lineages associated with different geographic locations. We used reverse transcription PCR and resequencing microarrays to detect LASV in 41 of 214 samples from rodents captured at 8 locations in Sierra Leone. Phylogenetic analysis of partial sequences of nucleoprotein (NP), glycoprotein precursor (GPC), and polymerase (L) genes showed 5 separate clades within lineage IV of LASV in this country. The sequence diversity was higher than previously observed; mean diversity was 7.01% for nucleoprotein gene at the nucleotide level. These results may have major implications for designing diagnostic tests and therapeutic agents for LASV infections in Sierra Leone. © 2015, Emerging Infectious Diseases. All rights reserved.

De Souza D.K.,University of Ghana | Ansumana R.,Center for Neglected Tropical Diseases | Ansumana R.,Mercy Hospital Research Laboratory | Sessay S.,Ministry of Health and Sanitation | And 6 more authors.
Parasites and Vectors | Year: 2015

Background: Many countries have made significant progress in the implementation of World Health Organization recommended preventive chemotherapy strategy, to eliminate lymphatic filariasis (LF). However, pertinent challenges such as the existence of areas of residual infections in disease endemic districts pose potential threats to the achievements made. Thus, this study was undertaken to assess the importance of these areas in implementation units (districts) where microfilaria (MF) positive individuals could not be found during the mid-term assessment after three rounds of mass drug administration. Methods: This study was undertaken in Bo and Pujehun, two LF endemic districts of Sierra Leone, with baseline MF prevalence of 2 % and 0 % respectively in sentinel sites for monitoring impact of the national programme. Study communities in the districts were purposefully selected and an assessment of LF infection prevalence was conducted together with entomological investigations undertaken to determine the existence of areas with residual MF that could enable transmission by local vectors. The transmission Assessment Survey (TAS) protocol described by WHO was applied in the two districts to determine infection of LF in 6-7 year old children who were born before MDA against LF started. Results: The results indicated the presence of MF infected children in Pujehun district. An. gambiae collected in the district were also positive for W. bancrofti, even though the prevalence of infection was below the threshold associated with active transmission. Conclusions: Residual infection was detected after three rounds of MDA in Pujehun - a district of 0 % Mf prevalence at the sentinel site. Nevertheless, our results showed that the transmission was contained in a small area. With the scale up of vector control in Anopheles transmission zones, some areas of residual infection may not pose a serious threat for the resurgence of LF if the prevalence of infections observed during TAS are below the threshold required for active transmission of the parasite. However, robust surveillance strategies capable of detecting residual infections must be implemented, together with entomological assessments to determine if ongoing vector control activities, biting rates and infection rates of the vectors can support the transmission of the disease. Furthermore, in areas where mid-term assessments reveal MF prevalence below 1 % or 2 % antigen level, in Anopheles transmission areas with active and effective malaria vector control efforts, the minimum 5 rounds of MDA may not be required before implementing TAS. Thus, we propose a modification of the WHO recommendation for the timing of sentinel and spot-check site assessments in national programs. © 2015 de Souza et al.

Meehan K.A.,Mercy Hospital Research Laboratory | Bankoski A.J.,George Mason University | Tejan E.,Mercy Hospital | Ansumana R.,Mercy Hospital Research Laboratory | And 3 more authors.
Ethnicity and Disease | Year: 2011

Objective: To identify the prevalence of hypertension among adults in Bo, Sierra Leone. Design: Hypertension data were extracted from outpatient clinic records. Setting: Mercy Hospital in urban Bo, Sierra Leone. Patients: All nonpregnant outpatients aged ≥15 years seen at the outpatient clinic in 2009. Main Outcome Measures: Prevalence of hypertension, defined as a systolic blood pressure ≥140 mm Hg and/or a diastolic blood pressure ≥90 mm Hg. Results: Data from 3944 individuals were analyzed (mean age 38.7 years). The overall prevalence of hypertension among those aged ≥15 years was 25.2%, with an age-adjusted prevalence of 19.6%. The prevalence of hypertension for participants aged ≥20 years was 27.1%, with an age-adjusted prevalence of 23.6%. There were no significant differences in blood pressure by sex. The prevalence of hypertension increased significantly with age for both males and females (P<.001). Conclusions: The prevalence of hypertension in Sierra Leone is consistent with the rates of hypertension observed in other parts of West Africa.

Ranasinghe S.,George Mason University | Ansumana R.,Mercy Hospital Research Laboratory | Ansumana R.,Njala University | Bockarie A.S.,Mercy Hospital Research Laboratory | And 4 more authors.
Malaria Journal | Year: 2015

Background: This analysis examined how the proportion of children less than 5-years-old who slept under a bed net the previous night changed during and after a national long-lasting insecticidal net (LLIN) distribution campaign in Sierra Leone in November-December 2010. Methods: A citywide cross-sectional study in 2010-2011 interviewed the caregivers of more than 3000 under-five children from across urban Bo, Sierra Leone. Chi squared tests were used to assess change in use rates over time, and multivariate regression models were used to examine the factors associated with bed net use. Results: Reported rates of last-night bed net use changed from 38.7 % (504/1304) in the months before the LLIN campaign to 21.8 % (78/357) during the week of the campaign to 75.3 % (1045/1387) in the months after the national campaign. The bed net use rate significantly increased (p < 0.01) from before the campaign to after the universal LLIN distribution campaign in all demographic, socioeconomic, and health behaviour groups, even though reported use during the campaign dropped significantly. Conclusion: Future malaria prevention efforts will need to promote consistent use of LLINs and address any remaining disparities in insecticide-treated bed net (ITN) use. © 2015 Ranasinghe et al.

Jacobus H.,U.S. Navy | Jacobus H.,Nova Research Inc. | Lin B.,U.S. Navy | Jimmy D.H.,Mercy Hospital Research Laboratory | And 3 more authors.
Energy Conversion and Management | Year: 2011

Hybrid power systems have the capability to incorporate significant renewable energy penetration for a small autonomous system while still maintaining reliable grid stability. While there are many papers covering the optimization of component size and dispatch strategy, far fewer papers contain experimental performance data from hybrid systems. Mercy Hospital in Bo, Sierra Leone is converting their power system into a photovoltaic (PV)-diesel hybrid system, thus providing an opportunity to examine the change in system performance before, during, and after the conversion. Due to the seasonal availability of electric power in Sierra Leone, two datasets representing two distinct load profiles are analyzed: Wet Season and Dry Season. The difference in generation efficiency,cost per kW h, generator runtime, and fuel consumption are calculated between a diesel-only generation baseline and the recorded hybrid system performance. The results indicated that the hybrid system significantly reduces operation costs; approximately 37% less during Dry Season and 64% reduction in the Wet Season than a diesel-only generator serving the same load. © 2011 Elsevier Ltd.

Discover hidden collaborations