Lassa Fever in Post-Conflict Sierra Leone

Background

Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world''s highest incidence of the disease.

Methodology/Principal Findings

Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs) in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone''s thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects.

Conclusions/Significance

Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to develop more effective and/or supplemental treatments for LF.     

Haemonchosis in sheep and goats in Sierra Leone

The incidence of haemonchosis in sheep and goats in Sierra Leone showed a seasonal variation with a high peak in the dry season (October to January) and a low one from March to May. Mean relative densities were significantly higher in young hosts and showed two peaks, a high one from August to December and a low one from April to June while the mean relative densities of old hosts were low and exhibited an irregular seasonal pattern with no defined peaks. The peak seasons in young hosts coincided approximately with the dry and rainy seasons. Male hosts showed an overall higher but not a significant mean relative density than females but for most of the months mean relative densities of infection of female hosts were not significantly higher than those of males. The roles of climatic conditions and arrested development (hypobiosis) and self-cure and host age immunity on Haemonchus contortus worm burdens are discussed.     

Treatment of onchocerciasis with ivermectin in Sierra Leone

Ivermectin chemotherapy is proving to be a major advance in the management of onchocerciasis. In this article, James Whitworth reviews the work done on onchocerciasis and ivermectin in Sierra Leone and examines the evidence that mass treatment might control the clinical features of the disease and its transmission in West Africa. Ivermectin is safe and effectively reduces microfilarial (mf) loads, with major improvement in some ocular manifestations o f disease. This alone makes mass distribution to communities at risk of blindness worthwhile, even though the impact on other clinical features is less clear cut. Repeated doses have a cumulative effect on adult worms, which may cause more reduction in transmission than hitherto thought likely.     

Achievements and challenges of lymphatic filariasis elimination in Sierra Leone

BackgroundLymphatic filariasis (LF) is targeted for elimination in Sierra Leone. Epidemiological coverage of mass drug administration (MDA) with ivermectin and albendazole had been reported >65% in all 12 districts annually. Eight districts qualified to implement transmission assessment survey (TAS) in 2013 but were deferred until 2017 due to the Ebola outbreak (2014–2016). In 2017, four districts qualified for conducting a repeat pre-TAS after completing three more rounds of MDA and the final two districts were also eligible to implement a pre-TAS.Methodology/Principal findingsFor TAS, eight districts were surveyed as four evaluation units (EU). A school-based survey was conducted in children aged 6–7 years from 30 clusters per EU. For pre-TAS, one sentinel and one spot check site per district (with 2 spot check sites in Bombali) were selected and 300–350 persons aged 5 years and above were selected. For both surveys, finger prick blood samples were tested using the Filariasis Test Strips (FTS).For TAS, 7,143 children aged 6–7 years were surveyed across four EUs, and positives were found in three EUs, all below the critical cut-off value for each EU. For the repeat pre-TAS/pre-TAS, 3,994 persons over five years of age were surveyed. The Western Area Urban had FTS prevalence of 0.7% in two sites and qualified for TAS, while other five districts had sites with antigenemia prevalence >2%: 9.1–25.9% in Bombali, 7.5–19.4% in Koinadugu, 6.1–2.9% in Kailahun, 1.3–2.3% in Kenema and 1.7% - 3.7% in Western Area Rural.Conclusions/SignificanceEight districts in Sierra Leone have successfully passed TAS1 and stopped MDA, with one more district qualified for conducting TAS1, a significant progress towards LF elimination. However, great challenges exist in eliminating LF from the whole country with repeated failure of pre-TAS in border districts. Effort needs to be intensified to achieve LF elimination.     

Medicinal Plant Trade in Sierra Leone: Threats and Opportunities for Conservation

This study used a quantitative market survey to examine the ecological importance of the medicinal plant trade in Sierra Leone and the existing trading systems, so that it could be determined (1) if trade has a negative impact on the species traded, and/or (2) if trade could be used to support conservation projects. We interviewed vendors in three major cities and two towns and carried out focus–group discussions among collectors at forest edge communities. In the markets, specimen samples were collected and identified. In several forests, observations were made on harvesting techniques and relative abundance. More than 40 species are traded in urban markets, nine of which are the most frequently traded. Some plants are transported great distances to reach the urban markets, especially Xylopia aethiopica (Dunal) A.Rich. and Garcinia kola Heckel. Certain species might not be sustainably harvested depending on the collector practices (e.g., ring debarking, tree felling), and this might threaten these species, especially Piper guineense Schumach. & Thonn. However, results also suggest that the trade of some species could be promoted as an alternative livelihood strategy for edge communities of forest reserves. In this latter case, special attention should be paid to sustainable harvesting techniques.     

Sulphur oxidation in tidal mangrove soils of Sierra Leone

Summary Tidal mangrove soil contained about 17-mg/g (oven-dry soil) of oxidisable sulphur, of which about 9 mg was insoluble in acetone. Samples showed considerable variability and this was shown to be due to the fact that decayed wood in the soil was heavily impregnated with oxidisable sulphur, a high proportion of which was insoluble in acetone. It is suggested that this proportion was the polysulphide fraction.When the soil was dried, its pH value fell to 3.0 to 2.4 due to the activity of sulphur-oxidising bacteria. When the pH value of the soil fell below 3 a rapid decline in the number of the organisms present occurred, and it is suggested that this was due to the increase in the availability of ferric iron which also occurred below this pH value.CaCO₃ had two main effects on sulphur oxidation; one on the sulphur-oxidising bacteria, increasing or decreasing sulphur oxidation according to whether the pH value was moved into or out of their range of activity, and an inhibitory effect on pyrites oxidation. The results indicate that the pyrites fraction was not oxidised above pH 3 and that it was not involved in acid-formation. It is suggested that pyrites oxidation under the experimental conditions was a chemical reaction possibly involving ferric ions.The possible application of the results to the reclamation of saline mangrove swamps is discussed.     

Fungi associated with selected fermented foods in Sierra Leone

Summary The mycoflora of two popular fermented foodstuffs of Sierra Leone, ogi from maize (Zea mays L.) and foofoo from cassava (Manihot esculenta Crantz), were determined before, during and after fermentation. Maize kernels containedAspergillus flavus, A. ochraceus, A. tamarii andPenicillium citrinum. Aflatoxins B₁ and G₁ and ochratoxin A were extracted from these kernels. Fresh cassava tubers had no mycoflora but the stored fermented product, dry ball foofoo, containedA. flavus, A. ochraceus andP. citrinum. The participation of fungi in either fermentation process was not observed. Ogi and dry ball foofoo also contained trace amounts of aflatoxin G₁. In ogi, while the amount of ochratoxin A was much the same as on the maize kernels, significantly low amounts of aflatoxin B₁ were detected. In addition to the known mycotoxins, a number of unidentified fluorescent compounds were isolated only in maize and dry ball foofoo.

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Moisissures associées avec certains aliments fermentés au Sierra Leone

Résumé La mycoflore de deux aliments fermentés, populaires au Sierra Leone, l'ogi de maïs (Zea mays Linn) et le foofoo de manioc (Manihot esculenta Crantz) est déterminée avant, pendant et après fermentation. Les grains de maïs contiennentAspergellus flavus, A. ochraceus, A. tamarii etPernicillium citrinum. On a extrait les aflatoxines B₁ et G₁ ainsi que l'ochratoxine A de ces grains. Les tubercules frais de manioc n'ont pas de mycoflore mais le produit fermenté conservé, le foofoo dry ball, contientA. flavus, A. ochraceus etP. citrinum. La participation des moisissures n'a été observée dans aucun des deux processus de fermentation. L'ogi et le foofoo dry ball contiennent aussi des traces d'aflatoxine G₁. Dans l'ogi, la quantité d'ochratoxine A est quasi la même que dans les grains de maïs, tandis que l'aflatoxine B₁ est déteetée en quantité significativement moindre. En plus des mycotoxines connues, un certain nombre de composés fluorescents non-identifiés ont pu être isolés mais seulement du maïs et du foofoo dry ball.

     

Ethonobotany and sustainable utilization of natural dye plants in Sierra Leone

An ethnobotanical survey of practicing dyers in the biodiversity rich ecosystems of Sierra Leone and of the literature was conducted on the common plant species used to produce natural dyes. In addition, the methods used to obtain these dyes and to dye fabric, together with the techniques used to produce various patterns on fabric were investigated. Although the thriving dye industry is now predominantly serviced by synthetic dyes, the knowledge of the plants used still survives among some dyers, who use plant dyes to some extent. However this indigenous knowledge is rapidly being lost as increasingly less of it is being passed on to succeeding generations. Several plants used in the dyeing process are documented, together with their taxonomic characteristics; local names; how the dyes are produced and fabric dyed; the colors obtained; in addition to how various patterns are designed. Sustainable utilization of this important renewable natural resource is discussed.     

Contesting expertise: anthropologists at the Special Court for Sierra Leone

This article examines how social anthropologists' expertise was employed in the international war crimes trials heard at the Special Court for Sierra Leone. It tracks how the anthropologists challenged the prosecution experts by raising concerns about their methodology and advancing a fundamental critique of abstract legal categories. The discussion between the experts centred on two contested issues: the character of the armed groups and the phenomenon of forced marriages during the civil war in Sierra Leone. The analysis of the experts' testimonies shows that the anthropologists were engaged in an epistemological contest with the prosecution experts. The article aims at understanding why the anthropologists' arguments had less resonance with the judges than the reports submitted by the prosecution experts. Beyond the courtroom, it also speaks to the general debate about expertise and ways to study it.     

Meat eating and ant dipping by wild chimpanzees in Sierra Leone

This report presents the first records of meat-eating and ant dipping by wild chimpanzees,Pan troglodytes, from Sierra Leone. The study was conducted in the proposed Outamba-Kilimi National Park, Northern Sierra Leone. Measurements of tools used to dip for driver ants, are compared with those from four other study sites in Africa. The results reveal some fundamentally common characteristics. From both faecal analysis and direct observation, evidence was found that the chimpanzees eat meat. These recordings indicate a varied choice of prey and add new species to those preyed upon by wild chimpanzees. These findings preliminarily support the idea that despite a wide geographical distribution throughout Africa, chimpanzees share some essential conventional behavioural patterns.     

Ochratoxin A and aflatoxins in breast milk samples from Sierra Leone

Breast milks from 113 mothers in two Under-Five Clinics in the Southern Province of Sierra Leone, namely, Njala and Bo, were examined for their mycotoxin content. Only 10 were mycotoxin-free. Eighty-eight per cent of samples contained various aflatoxins and 35% contained ochratoxin A (OTA). Few samples (15%) had a single mycotoxin. Thirty-six (32%) had two mycotoxins and 50 (40%) had three or more. The occurrence of OTA in combination with various aflatoxins was recorded. It is concluded that infants in Sierra Leone are exposed to OTA and aflatoxins at levels which in some cases far exceed those permissible in animal feed in developed countries.