127 research outputs found
Tiered laboratory analyses for common infections to characterize febrile morbidity not related to malaria in Sierra Leone
In tropical Africa, fever is commonly associated with malaria. However, there are many other illnesses presenting with fever. Non-malaria febrile illnesses (NMFIs) may be attributable to multiple etiologic agents including viral, bacterial and parasitic infections in malaria-endemic resource-poor countries. NMFIs pose challenges to peripheral health systems such that they are clinically under-diagnosed while malaria remains over-diagnosed. Misdiagnoses of a febrile condition may lead to wrong prescription that delays treatment and increases expenditure on health-care and also leads to increased morbidity and mortality. In Sierra Leone, dealing with infections other than malaria remain a serious problem, starting from diagnosis to providing care. Several factors make it difficult to test and treat for NMFIs. Fewer febrile people report their fevers to healthcare centers and there are fewer resources generally which include: fewer laboratories, insufficiently trained laboratory technicians, inadequate standardized infrastructure and unsuitable equipment, epileptic power supplies as well as poor cold-chain storage conditions for reagents among others. The primary goal of this Ph.D. study was to investigate the prevalence/incidence of NMFIs in Bo, Sierra Leone, using a tiered laboratory analyzes method. The specific objectives were to: investigate the types and etiology of non-malarial febrile illnesses in Bo, Sierra Leone; determine the prevalence/incidence of non-malarial pathogens causing febrile illnesses, and investigate the distribution of NMFIs. The study started with a baseline and syndromic survey of all households in the study community (n=882 households with 5410 persons). A total cohort of 1403 persons was recruited and followed for a period of one year. After obtaining informed-consent, bio-samples were obtained from febrile subjects and used for laboratory analyses involving three tiers. The first tier (T1) included the use of rapid, lateral flow assays (RLFAs). T1 tests were: chikungunya, malaria, typhoid fever, syphilis, HIV, hepatitis A, B and C, dengue fever, leptospirosis, influenza A and B, RSV and Streptococcus aureus. Subsequent tests at Tier 2 included singleplex and multiplex PCR and bacterial culture; with resequencing pathogen microarray at Tier 3. From the initial survey 882 households with 5410 individuals and 76.6% reported having malaria in a month prior to the study. About 1402 (25.9%) of persons in participating households were reported to have had a fever within the past six months. The rate of fever reported differed by age group and sex, with young children having the highest rate (
Seroepidemiology of HIV in Moyamba District, Sierra Leone, 2013-2016
HIV infection is one of the health problems plaguing resource-poor countries. There are limited data on the prevalence in remote towns and districts. In this study we aimed at investigating the seroprevalence of HIV in Moyamba District using data from voluntary counseling and testing(VCT), prevention of mother-to-child transmission of HIV(PMCT) and from blood donors from 2013 to 2016.The seroprevalence of HIV from VCT was 2.87%(357/12434) for the four years, 2013 to 2016. Seroprevalence from PMCT was 0.91%(153/16,745) while the prevalence from healthy blood donors was 1.53%(27/1756). Overall, 537 persons tested positive for HIV out of 30,935 persons tested in Moyamba from 2013 to 2016 with a prevalence of 1.74(95%CI:1.6-1.89%).Statistically, our result is significantly different from the results of the DHS where HIV seroprevalence was reported at 1.0% in Moyamba(P<0.001).Our result provide an update on the HIV situation in Moyamba and shows an epidemic that is consistent with the national seroprevalence of 1.5%
CHANGING TRENDS IN THE DIAGNOSIS OF MALARIA AND TYPHOID FEVER
Malaria In tropical Africa, fever is commonly associated with malaria that was known variously as Roman fever,  marsh fever(Rocco 2003),  and whose name was derived from the Italian ‘Mal=bad, Aria=air.’(Prakash et al. 2013).   Malaria is caused by five species of the plasmodium parasite: P. falciparum, P. vivax, P.ovale, P. malariae and P. knowlesi all of which are transmitted by the female anopheles mosquito, which is the vector of the parasite. Over 2.4 billion people are at risk of P. falciparum infection, which results in about 300 to 500 million clinical episodes and 1million deaths annually (Bousema & Drakeley 2011). While about 2.9 billion persons are at risk for P. vivax infection with up to 300 million clinical episodes per year(Bousema & Drakeley 2011). A vast proportion of malaria morbidity occurs in sub-Saharan Africa, (SSA). However, there is substantial evidence that the intensity of malaria transmission in Africa is declining (Snow et al. 2012, Graz et al. 2011), and rapid malaria parasitemia tests are well distributed in endemic countries and easy to use (Graz et al. 2011).   Certain recent developments, however, are worth considering when assessing malaria burden and control.First, the discovery of Plasmodium falciparum with deleted histidine-rich repeat region of the histidine-rich-protein 2 and the evidence that parasites not detected by HRP2 lateral flow immunoassay(LFI) cause latent infection(Koita et al. 2012), is of extreme importance in endemic countries such as Sierra Leone, where HRP2 LFIs are predominantly used. LFIs have made malaria testing ubiquitous in sub-Saharan Africa, including in very remote areas. However, false negatives resulting from deleted hrp2 in certain P.falciparum may result in lower prevalence reports. The alternative dipstick to HRP2 LFIs is the Plasmodium lactate dehydrogenase (pLDH)-based LFI. However, in Sierra Leone, the use of pLDH LFIs is less common, and a similar trend exists in the other parts of Sub-Saharan Africa. LFIs were intended to be used primarily in resource-limited locations where expert microscopists are unavailable. So the use of LFIs is not routinely duplicated with smear results in many developing countries. This could be a setback for resource-poor settings.The use of point of care, multiplex molecular detection methods have been highlighted as a means of salvaging diagnosis in resource-poor countries, but cost remains a major limitation. Notwithstanding, PCR is emerging as most sensitive malaria diagnostic apart from rapid antigen tests. Antigens and DNA may persist in blood after parasite clearance through treatment. A plausible alternative has sought sexual stages of malaria parasites representing a small fraction of parasites during infection(Tao et al. 2014), but which can also be detected in body fluids such as saliva. Prior evidence indicates that saliva is an excellent non-invasive candidate for rapid malaria testing (Fung et al. 2012), but this aspect of malaria diagnostics is still under development including rapid tests based on nano trap technology.There has been a renewed global commitment for malaria elimination and both symptomatic and asymptomatic malaria infections are critical for the elimination of malaria. Novel diagnosis of subclinical malaria targeting sexual stages of the parasite are emerging, but the best candidate for such diagnostics are those that could be adaptable to the resource-poor settings in Africa. One such candidate is the nano trap, saliva-based, malaria rapid test that is under development by Johns Hopkins(http://www.jhsph.edu/news/news-releases/2015/johns-hopkins-bloomberg-school-of-public-health-researchers-receive-grant-to-evaluate-malaria-detection-test.html). Typhoid Fever In the case of typhoid fever, there seems to be an over-diagnosis.  The gold standard for the diagnosis of typhoid is by blood culture, which has a sensitivity of 40-60%(Parry et al. 1999), but low-cost tests, mainly the widal test, are more adaptable to resource-poverty and are commonly used in resource-poor settings such as Sierra Leone. Widal tests have been in use for over 110 years, but the results are very controversial(Olopoenia & King 2000, Nga et al. 2012),  and the test suffers from low specificity in endemic countries probably as a result of an increase in population antibody levels (Clegg et al. 1994).A positive Widal test does not always denote the presence of typhoid fever. Apart from increased population antibody levels, there exist up to 40 cross-reacting antigens between Salmonella enterica serotype Typhi and other Enterobacteriaceae(Parry et al. 1999). Cross-reacting antigens could also be from malaria, brucellosis, dengue fever, chronic liver disease or endocarditis(Colle et al. 1996).Blood culture which is the gold standard is time-consuming and may delay treatment apart from its inherently low sensitivity. Several typhoid dipsticks have been reported, but side-by-side independent assessments in endemic countries do not always yield the expected outcome.Polymerase chain reaction is currently a better option for diagnosing typhoid fever with same day result, but cost remains a big issue in countries that could be most in need. While suitable alternatives based on economic conditions of countries are sought, the cut-off value for the widal test requires evaluation and standardization. Having a wrong diagnosis at the point of care could lead to wrong clinical outcomes.
Impact of infectious disease epidemics on tuberculosis diagnostic, management, and prevention services: experiences and lessons from the 2014–2015 Ebola virus disease outbreak in West Africa
SummaryThe World Health Organization (WHO) Global Tuberculosis Report 2015 states that 28% of the world's 9.6 million new tuberculosis (TB) cases are in the WHO Africa Region. The Mano River Union (MRU) countries of West Africa–Guinea, Sierra Leone, and Liberia–have made incremental sustained investments into TB control programmes over the past two decades. The devastating Ebola virus disease (EVD) outbreak of 2014–2015 in West Africa impacted significantly on all sectors of the healthcare systems in the MRU countries, including the TB prevention and control programmes. The EVD outbreak also had an adverse impact on the healthcare workforce and healthcare service delivery. At the height of the EVD outbreak, numerous staff members in all MRU countries contracted EBV at the Ebola treatment units and died. Many healthcare workers were also infected in healthcare facilities that were not Ebola treatment units but were national hospitals and peripheral health units that were unprepared for receiving patients with EVD. In all three MRU countries, the disruption to TB services due to the EVD epidemic will no doubt have increased Mycobacterium tuberculosis transmission, TB morbidity and mortality, and patient adherence to TB treatment, and the likely impact will not be known for several years to come . In this viewpoint, the impact that the EVD outbreak had on TB diagnostic, management, and prevention services is described. Vaccination against TB with BCG in children under 5 years of age was affected adversely by the EVD epidemic. The EVD outbreak was a result of global failure and represents yet another ‘wake-up call’ to the international community, and particularly to African governments, to reach a consensus on new ways of thinking at the national, regional, and global levels for building healthcare systems that can sustain their function during outbreaks. This is necessary so that other disease control programmes (like those for TB, malaria, and HIV) are not compromised during the emergency measures of a severe epidemic
Child bed net use before, during, and after a bed net distribution campaign in Bo, Sierra Leone
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 \u3c 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 remain- ing disparities in insecticide-treated bed net (ITN) use
An ethics of anthropology-informed community engagement with COVID-19 clinical trials in Africa
The COVID-19 pandemic has reinforced the critical role of ethics and community engagement in designing and conducting clinical research during infectious disease outbreaks where no vaccine or treatment already exists. In reviewing current practices across Africa, we distinguish between three distinct roles for community engagement in clinical research that are often conflated: 1) the importance of community engagement for identifying and honouring cultural sensitivities; 2) the importance of recognising the socio-political context in which the research is proposed; and 3) the importance of understanding what is in the interest of communities recruited to research according to their own views and values. By making these distinctions, we show that current practice of clinical research could draw on anthropology in ways which are sometimes unnecessary to solicit local cultural values, overlook the importance of socio-political contexts and wider societal structures within which it works, potentially serving to reinforce unjust political or social regimes, and threaten to cast doubt on the trustworthiness of the research. We argue that more discerning anthropological engagement as well as wider collaboration with other social scientists and those working in the humanities is urgently needed to improve the ethics of current biomedical and pharmaceutical research practice in Africa
The "ready-to-hand" test:Diagnostic availability and usability in primary health care settings in Sierra Leone
This article assesses the availability of essential diagnostic tests in primary health care facilities in two districts in Sierra Leone. In addition to evaluating whether a test is physically present at a facility, it extends the concept of availability to include whether equipment is functional and whether infrastructure, systems, personnel and resources are in place to allow a particular test to be "ready to hand", that is, available for immediate use when needed. Between February 2019 and September 2019, a cross-sectional mixed-methods survey was conducted in all 40 Community Health Centres (CHCs) in Western Area, one of five principal divisions in Sierra Leone. The number of rapid diagnostic tests (RDTs) available ranged from 1-12, with 75% of facilities having 9 or less RDTs available out of a possible 17. While RDTs were overall more widely present than manual assays, there was wide variation between tests. The presence of RDTs at individual facilities was associated with having a permanent laboratory technician on staff. Despite CHCs being formally designated as providing laboratory services, no CHC fulfilled standard World Health Organisation (WHO) criteria for a laboratory. Only 9/40 (22.5%) CHCs had a designated laboratory space and a permanently employed laboratory technician. There was low availability of essential equipment and infrastructure. Supply chains were fragmented and unreliable, including a high dependency (>50%) on informal private sources for the majority of the available RDTs, consumables, and reagents. We conclude that the readiness of diagnostic services, including RDTs, depends on the presence and functionality of essential infrastructure, human resources, equipment and systems and that RDTs are not on their own a solution to infrastructural failings. Efforts to strengthen laboratory systems at the primary care level should take a holistic approach and focus on whether tests are "ready-to-hand" in addition to whether they are physically present
The impact of residual infections on Anopheles-transmitted Wuchereria bancrofti after multiple rounds of mass drug administration
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
Rat-atouille: A Mixed Method Study to Characterize Rodent Hunting and Consumption in the Context of Lassa Fever
Lassa fever is a zoonotic hemorrhagic illness predominant in areas across Nigeria, Sierra Leone, Guinea, Liberia, and southern Mali. The reservoir of Lassa virus is the multimammate mouse (Mastomys natalensis), a highly commensal species in West Africa. Primary transmission to humans occurs through direct or indirect contact with rodent body fluids such as urine, feces, saliva, or blood. Our research draws together qualitative and quantitative methods to provide a fuller and more nuanced perspective on these varied points of human–animal contact. In this article, we focus on the hunting, preparation, and consumption of rodents as possible routes of exposure in Bo, Sierra Leone. We found that the consumption of rodents, including the reservoir species, is widespread and does not neatly tally against generational or gender lines. Further, we found that the reasons for rodent consumption are multifactorial, including taste preferences, food security, and opportunistic behavior. We argue that on certain topics, such as rodent consumption, establishing trust with communities, and using qualitative research methods, is key to investigate sensitive issues and situate them in their wider context. To conclude, we recommend ways to refine sensitization campaigns to account for these socio-cultural contexts
Attitudes toward home-based malaria testing in rural and urban Sierra Leone
Background
The purpose of this study was to examine malaria testing practices and preferences in Bo, Sierra Leone, and to ascertain interest in and willingness to take a home-based rapid diagnostic test administered by a community health volunteer (CHV) or a trained family member rather than travelling to a clinical facility for laboratory-based testing.
Methods
A population-based, cross-sectional survey of 667 randomly-sampled rural households and 157 urban households was conducted in December 2013 and January 2014.
Results
Among rural residents, 69% preferred a self/family- or CHV-conducted home-based malaria test and 20% preferred a laboratory-based test (with others indicating no preference). Among urban residents, these numbers were 38% and 44%, respectively. If offered a home-based test, 28% of rural residents would prefer a self/family-conducted test and 68% would prefer a CHV-assisted test. For urban residents, these numbers were 21% and 77%. In total, 36% of rural and 63% of urban residents reported usually taking a diagnostic test to confirm suspected malaria. The most common reasons for not seeking malaria testing were the cost of testing, waiting to see if the fever resolved on its own, and not wanting to travel to a clinical facility for a test. In total, 32% of rural and 27% of urban participants were very confident they could perform a malaria test on themselves or a family member without assistance, 50% of rural and 62% of urban participants were very confident they could perform a test after training, and 56% of rural and 33% of urban participants said they would pay more for a home-based test than a laboratory-based test.
Conclusion
Expanding community case management of malaria to include home testing by CHVs and family members may increase the proportion of individuals with febrile illnesses who confirm a positive diagnosis prior to initiating treatment
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