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Background: Antenatal period is an opportunity for reaching pregnant women with vital interventions. In fact, antenatal care (ANC) coverage was an indicator for assessing progress towards the Millennium Development Goals. This paper applies a novel index of service coverage using ANC, which accounts for every ANC visit. An index of service coverage gap is also proposed. These indices are additively decomposable by population groups and they are sensitive to the receipt of more ANC visits below a defined threshold. These indices have also been generalised to account for the quality of services. Methods: Data from recent rounds of the Demographic and Health Survey (DHS) are used to reassess ANC service coverage in 35 sub-Saharan African countries. An index of ANC coverage was estimated. These countries were ranked, and their ranks are compared with those based on attaining at least four ANC visits (ANC4+). Findings: The index of ANC coverage reflected the level of service coverage in countries. Further, disparities exist in country ranking as some countries, e.g. Cameroon, Benin Republic and Nigeria are ranked better using the ANC4+ indicator but poorly using the proposed index. Also, Rwanda and Malawi are ranked better using the proposed index. Conclusion: The proposed ANC index allows for the assessment of progressive realisation, rooted in the move towards universal health coverage. In fact, the index reflects progress that countries make in increasing service coverage. This is because every ANC visit counts. Beyond ANC coverage, the proposed index is applicable to assessing service coverage generally including quality education. [ABSTRACT FROM AUTHOR]

Objective: To characterize the impact of widespread inventory management policies on stock-outs of essential drugs in Zambia’s health clinics and develop related recommendations. Methods: Daily clinic storeroom stock levels of artemether-lumefantrine (AL) products in 2009–2010 were captured in 145 facilities through photography and manual transcription of paper forms, then used to determine historical stock-out levels and estimate demand patterns. Delivery lead-times and estimates of monthly facility accessibility were obtained through worker surveys. A simulation model was constructed and validated for predictive accuracy against historical stock-outs, then used to evaluate various changes potentially affecting product availability. Findings: While almost no stock-outs of AL products were observed during Q4 2009 consistent with primary analysis, up to 30% of surveyed facilities stocked out of some AL product during Q1 2010 despite ample inventory being simultaneously available at the national warehouse. Simulation experiments closely reproduced these results and linked them to the use of average past monthly issues and failure to capture lead-time variability in current inventory control policies. Several inventory policy enhancements currently recommended by USAID | DELIVER were found to have limited impact on product availability. Conclusions: Inventory control policies widely recommended and used for distributing medicines in sub-Saharan Africa directly account for a substantial fraction of stock-outs observed in common situations involving demand seasonality and facility access interruptions. Developing central capabilities in peripheral demand forecasting and inventory control is critical. More rigorous independent peer-reviewed research on pharmaceutical supply chain management in low-income countries is needed. [ABSTRACT FROM AUTHOR]

The adoption of the shared prosperity goal by the World Bank in 2013 and Sustainable Development Goal 10, on inequality, by the United Nations in 2015 should strengthen the focus of development interventions and cooperation on the income growth of the bottom 40 percent of the income distribution. This paper contributes to the incipient literature on within-country allocations of development institutions and assesses the geographic targeting of World Bank projects to the bottom 40 percent. Bivariate correlations between the allocation of project funding approved over 2005–14 and the geographical distribution of the bottom 40 as measured by survey income or consumption data are complemented by regressions with population and other potential factors affecting the within-country allocations as controls. The correlation analysis shows that, of the 58 countries in the sample, 41 exhibit a positive correlation between the shares of the bottom 40 and World Bank funding, and, in almost half of these, the correlation is above 0.5. Slightly more than a quarter of the countries, mostly in Sub-Saharan Africa, exhibit a negative correlation. The regression analysis shows that, once one controls for population, the correlation between the bottom 40 and World Bank funding switches sign and becomes significant and negative on average. This is entirely driven by Sub-Saharan Africa and not observed in the other regions. Hence, the significant and positive correlation in the estimations without controlling for population suggests that World Bank project funding is concentrated in administrative areas in which more people live (including the bottom 40) rather than in poorer administrative areas. Furthermore, capital cities receive disproportionally high shares of World Bank funding on average. [ABSTRACT FROM AUTHOR]

Objective: To examine whether childbearing before age 18 in Sub-Saharan Africa is associated with increased risk of maternal and child complications through a systematic literature review and meta-analysis. Methods: The literature on adolescent pregnancy and associated complications in Sub-Saharan Africa was reviewed. A systematic electronic database search in Medline and Embase identified relevant papers. Studies were eligible for inclusion if they had numeric data on maternal mortality, pre-eclampsia, eclampsia, preterm birth, low birth weight, small for gestational age, stillbirth, neonatal death or perinatal death. We included studies on adolescents aged 17 years or younger, and with a comparison group of adult women aged between 20 and 35 years. The quality of the articles was assessed. Meta-analyses were conducted when there were at least three included studies with minor clinical heterogeneity in population and outcome measures. Results: Eighteen studies met our inclusion criteria. There were many studies from Sub-Saharan Africa with data on the age group 15–19 years old, but few studies had separate data on adolescents <18 years old. All included studies were of either moderate or low quality. Adolescents had an increased risk of low birth weight, pre-eclampsia/eclampsia, preterm birth and maternal and perinatal mortality. We found a lower, nonsignificant risk of stillbirth and for small for gestational age babies among the young mothers. Conclusion: In this systematic review, the findings indicate that young maternal age is associated with some unfavorable outcomes in Sub-Saharan Africa. High quality observational studies that adjust for sociodemographic factors are lacking. [ABSTRACT FROM AUTHOR]

In Zambia, as well as many other African and non-Western cultures, the extent and kind of children's chores may contribute to their learning, yet often also conflict with their schooling. In the moderation analysis we present in this manuscript, we aimed to explore the interactive effects of schooling and chores on children's mathematics performance at different levels of math knowledge and computational skill, taking into account how the assessment questions were presented. The sample consisted of 1,535 children (719 girls) living in rural and peri-urban communities in Zambia who were administered the Zambia Achievement Test (ZAT). We categorized the 60 items of the ZAT by their targeted content knowledge, sizes of the numbers involved, and forms of representation. Our results showed that chores supported the development of very basic mathematics skills and knowledge in children who had less schooling, but also significantly lowered the performance of students who were in school once their school attendance rose above certain levels. Moreover, this interaction between chores and school attendance was observed predominantly in girls, with a lesser effect of chores on boys. [ABSTRACT FROM AUTHOR]

Background: Newborns are at greatest risk of dying at and shortly after the time of birth. Newborn mortality remains an urgent concern and is an important indicator of child health, development and well-being. Studies examining the effectiveness of antenatal care on maternal and newborn health outcomes have provided conflicting results. The aim of this review and meta-analysis was to determine the pooled effect of antenatal care on neonatal mortality in sub-Saharan Africa. Methods: We searched PubMed, Medline, EMBASE, CINAHL and Google Scholar from September to November 2016 and then updated our search on April 13, 2019. Two independent reviewers extracted data from eligible studies. The quality of each included study was assessed using the Risk of Bias Assessment tool for Non-Randomized Studies (RoBANS). The results were reported based on risk ratio (RR) with 95% confidence intervals (CI) using a random-effects model. Results: Eight hundred and ninety eight studies were initially identified. During screening, 23 studies were found to be relevant for data extraction. Of these, only twelve studies fulfilled the inclusion criteria and were included in the analysis. In five of the twelve studies included in the analysis, antenatal care service utilization had a significant association with neonatal mortality. The pooled risk ratio by the random-effects model was 0.61 (95% CI: 0.43, 0.86) for neonates born to women who received at least one antenatal care visit by a skilled provider as compared to neonates born to women who did not receive antenatal care. Conclusion: This review indicates that utilization of at least one antenatal care visit by a skilled provider during pregnancy reduces the risk of neonatal mortality by 39% in sub-Saharan African countries. Thus, in order to accelerate progress towards the reduction of newborn deaths, all pregnant women should receive antenatal care during pregnancy. [ABSTRACT FROM AUTHOR]

Introduction: Approximately 14 million unintended pregnancies are recorded annually in sub-Saharan Africa (SSA). We sought to investigate the prevalence and determinants of unintended pregnancies among women in sub-Saharan Africa. Materials and methods: The study pooled data from current Demographic and Health Surveys (DHS) conducted from January 1, 2010 to December 31, 2016 from 29 countries in SSA. Logistic regression analysis was used to examine the factors that influence unintended pregnancies in SSA. Results were presented using odds ratios (OR). Results: We found overall unintended pregnancy prevalence rate of 29%, ranging from 10.8% in Nigeria to 54.5% in Namibia. As compared to women aged 15–19 years, women of all other age categories had higher odds of unintended pregnancies. Married women were 6 times more probable to report unintended pregnancy as compared to women who had never married (OR = 6.29, CI = 5.65–7.01). The phenomenon had higher odds among rural residents as compared to urban residents (OR = 1.08, CI = 1.01–1.16). Women with primary (OR = 0.74, CI = 0.69–0.80) and secondary (OR = 0.71, CI = 0.65–0.77) levels of education had less chances of unintended pregnancies, compared to those with no education. Again, women in all other wealth categories had less probability of unintended pregnancy, as compared to women with poorest wealth status. Conclusion: Our study contributes substantially towards the discourse of maternal wellbeing by unveiling the prevalence and determinants of unintended pregnancy across the SSA region. There is the need for SSA countries with high prevalence of unintended pregnancies to consider past and present successful interventions of other countries within the region such as health education, counselling, skills-building, comprehensive sex education and access to contraception. Much of these efforts rest with the governments of SSA countries. [ABSTRACT FROM AUTHOR]

Background: Increased second-line antiretroviral therapy (ART) failure rate narrows future options for HIV/AIDS treatment. It has critical implications in resource-limited settings; including sub-Saharan Africa (SSA) where the burden of HIV-infection is immense. Hence, pooled estimate for second-line HIV treatment failure is relevant to suggest valid recommendations that optimize ART outcomes in SSA. Methods: We retrieved literature systematically from PUBMED/MEDLINE, EMBASE, CINAHL, Google Scholar, and AJOL. The retrieved studies were screened and assessed for eligibility. We also assessed the eligible studies for their methodological quality using the Joanna Briggs Institute’s appraisal checklist. The pooled estimates for second-line HIV treatment failure and its associated factors were determined using STATA, version 15.0 and MEDCALC, version 18.11.3, respectively. We assessed publication bias using Comprehensive Meta-analysis software, version 3. Detailed study protocol for this review/meta-analysis is registered and found on PROSPERO (ID: CRD42018118959). Results: A total of 33 studies with the overall 18,550 participants and 19,988.45 person-years (PYs) of follow-up were included in the review. The pooled second-line HIV treatment failure rate was 15.0 per 100 PYs (95% CI: 13.0–18.0). It was slightly higher at 12–18 months of follow-up (19.0/100 PYs; 95% CI: 15.0–22.0), in children (19.0/100 PYs; 95% CI: 14.0–23.0) and in southern SSA (18.0/100 PYs; 95% CI: 14.0–23.0). Baseline values (high viral load (OR: 5.67; 95% CI: 13.40–9.45); advanced clinical stage (OR: 3.27; 95% CI: 2.07–5.19); and low CD4 counts (OR: 2.80; 95% CI: 1.83–4.29)) and suboptimal adherence to therapy (OR: 1.92; 95% CI: 1.28–2.86) were the factors associated with increased failure rates. Conclusion: Second-line HIV treatment failure has become highly prevalent in SSA with alarming rates during the 12–18 month period of treatment start; in children; and southern SSA. Therefore, the second-line HIV treatment approach in SSA should critically consider excellent adherence to therapy, aggressive viral load suppression, and rapid immune recovery. [ABSTRACT FROM AUTHOR]

Background: The prevalence of hypertension is highest in the African Region with 46% of adults aged 25 and above diagnosed with hypertension, while the lowest prevalence of 35% is found in the Americas. There is sparse evidence on the approaches used to prevent hypertension in Sub-Saharan Africa and the effectiveness of these approaches. It is therefore imperative that a systematic review; which synthesises all the available evidence on the approaches and their impact is conducted to inform public health policy and practice. Objective: To synthesise evidence on the interventions used for the primary prevention of hypertension in Sub-Saharan Africa and to evaluate the effectiveness of these interventions in reducing blood pressure, hypertension prevalence and the risk factors for hypertension. Methods and results: This systematic review was reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Bibliographic databases were searched on the 4th-17th of January 2018 from 1970 to January 2018 and on the 5th of May 2019 from 1970 to May 2019, for studies focusing on the primary prevention of hypertension in communities in Sub-Saharan Africa. A narrative synthesis was conducted based on study interventions and outcomes. Also, a meta-analysis was carried out using pooled mean differences; using a random effects model of generic inverse variance option in RevMan. A total of 854 studies were identified after deduplication, with thirteen studies meeting the inclusion criteria. Six studies with varying interventions and methodologies observed a significant pooled reduction in systolic blood pressure of -3.3mmHg (95%CI -4.64 to -1.96) and a reduction of -2.26mmHg (95%CI -6.36 to 1.85) in diastolic blood pressure, which was not statistically significant (p = 0.28). Also, moderate to significant heterogeneity was observed (I2 = 68% and 99%) for the systolic and diastolic blood pressure respectively. Intervention and study design accounted for 100% heterogeneity for both systolic and diastolic blood pressure (r2 = 100%). Conclusion: Health promotion and interventions targeting various risk factors of hypertension and, salt consumption restriction interventions have been employed in Sub-Saharan Africa with varying levels of success. We recommend that higher quality studies and a meta-analysis are needed to evaluate the impact of these interventions and to inform public health policy and practice. [ABSTRACT FROM AUTHOR]

Lead and malaria both present significant health risks to children in Sub-Saharan Africa. Previous studies have shown that high blood lead levels in children act as a protective factor against subsequent malaria incidence. The main objective of this study was to investigate associations between blood lead level and malaria outcomes prospectively in Beninese children from 12 to 24 months of age. Two-hundred and four children were assessed for lead at 12 months and closely followed until 24 months for malaria; when symptoms and parasite density were also recorded. Univariate and multivariate negative binomial and linear regression models tested associations between blood lead level quartile and total episodes of malaria (total symptomatic and asymptomatic episodes) and parasite density, respectively. Median blood lead level among children measured at 12 months was 56.50 (4.81–578) μg/L. During the 12-month follow-up, 172 (84.31%) children had at least one malaria episode. Univariate and multivariate negative binomial and linear regressions did not reveal significant associations between blood lead level quartile and malaria outcomes. Iron deficiency was not found to be an effect modifier. Results from this prospective child-cohort study investigating associations between blood lead level and malaria did not confirm results from previous cross-sectional studies. Further research is needed to further explore this relationship and other co-morbidities due to malaria and lead. [ABSTRACT FROM AUTHOR]

Background: Long acting reversible and permanent contraception (LARPs) offer promising opportunities for addressing the high and growing unmet need for modern contraception and helps to reduce unintended pregnancies and abortion rates in sub-Saharan Africa (SSA). This study examines the contextual factors that influence the use of long acting reversible and permanent contraception among married and fecund women in Ethiopia. Method: We use data from the 2016 Ethiopian Demographic and Health Survey to examine the contextual factors that influence choice of long acting reversible and permanent contraception among married, non-pregnant and fecund women. The DHS collects detailed information on individual and household characteristics, contraception, and related reproductive behaviors from women of reproductive age. In addition, we created cluster level variables by aggregating individual level data to the cluster level. Analysis was done using a two-level multilevel logistic regression with data from 6994 married (weighted = 7352) women residing in 642 clusters (communities). Results: In 2016, 12% of married, non-pregnant and ‘fecund’ women were using long-acting reversible and permanent methods of contraception in Ethiopia. A higher proportion of women with secondary and above education (17.6%), urban residents (19.7%), in the richest wealth quintile (18.3%) and in paid employment (18.3%) were using LARP methods compared to their counterparts. Regression analysis showed that community level variables such as women’s empowerment, access to family planning information and services, region of residence and knowledge of methods were significantly associated with use of LARP methods. Age, wealth status, employment status and women’s fertility preferences were among the individual and household level variables associated with choice of LARP methods. With regards to age, the odds of using LARP methods was significantly lower among adolescents (OR, 0.53; 95% CI, 0.32–0.85) and women over the age of 40 (OR, 0.63; 95% CI, 0.44–0.90) compared to women in their 20’s. Conclusion: The findings of this study indicate that the demand for long-acting reversible and permanent contraception is influenced not only by women’s individual and household characteristics but also by the community’s level of women’s empowerment, socio-economic development, as well as access and exposure to family planning information and services. Thus, improving knowledge of long-acting reversible and permanent methods, improving women’s decision making autonomy and upgrading the capacity and skills of health workers particularly the midlevel providers and community health extension workers on the provision of LARP methods and rights-based approach is important to improve the uptake of LARP methods. [ABSTRACT FROM AUTHOR]

Sub-Saharan Africa (SSA) lagged furthest behind in achieving targets for the millennium development goals (MDG). We investigate the hypothesis that its slow progress is influenced by political factors. Longitudinal data on three health MDG indicators: under-five mortality, maternal mortality and HIV prevalence rates were collated from 1990 to 2012 in 48 countries. Countries were grouped into geo-political and eco-political groups. Groupings were based on conflict trends in geographical regions and the International Monetary Fund’s classification of SSA countries based on gross national income and development assistance respectively. Cumulative progress in each group was derived and main effects tested using ANOVA. Correlation analysis was conducted between political variables – POLITY 2, fragile state index (FSI), voter turnout rates, civil liberty scores (CLS) and the health variables. Our results suggest a significant main effect of eco-political and geo-political groups on some of the health variables. Political conflict as measured by FSI and political participation as measured by CLS were stronger predictors of slow progress in reducing under-five mortality rates and maternal mortality ratios. Our findings highlight the need for further research on political determinants of mortality in SSA. Cohesive effort should focus on strengthening countries’ political, economic and social capacities in order to achieve sustainable goals beyond 2015. [ABSTRACT FROM PUBLISHER]

Background: Multidrug resistant tuberculosis (MDR-TB), is an emerging public health problem in sub-Saharan Africa (SSA). This study aims to determine the trends in prevalence of MDR-TB among new TB cases in sub-Saharan Africa over two decades. Methods: We searched electronic data bases and accessed all prevalence studies of MDR-TB within SSA between 2007 and 2017. We determined pooled prevalence estimates using random effects models and determined trends using meta-regression. Results: Results: We identified 915 studies satisfying inclusion criteria. Cumulatively, studies reported on MDR-TB culture of 34,652 persons. The pooled prevalence of MDR-TB in new cases was 2.1% (95% CI; 1.7–2.5%). There was a non-significant decline in prevalence by 0.12% per year. Conclusion: We found a low prevalence estimate of MDR-TB, and a slight temporal decline over the study period. There is a need for continuous MDR-TB surveillance among patients with TB. [ABSTRACT FROM AUTHOR]

Background: People of Sub Saharan Africa (SSA) and South Asians(SA) ethnic minorities living in Europe have higher risk of stroke than native Europeans(EU). Study objective is to provide an assessment of gender specific absolute differences in office systolic(SBP) and diastolic(DBP) blood pressure(BP) levels between SSA, SA, and EU. Methods and Findings: We performed a systematic review and meta-analysis of observational studies conducted in Europe that examined BP in non-selected adult SSA, SA and EU subjects. Medline, PubMed, Embase, Web of Science, and Scopus were searched from their inception through January 31st 2015, for relevant articles. Outcome measures were mean SBP and DBP differences between minorities and EU, using a random effects model and tested for heterogeneity. Twenty-one studies involving 9,070 SSA, 18,421 SA, and 130,380 EU were included. Compared with EU, SSA had higher values of both SBP (3.38 mmHg, 95% CI 1.28 to 5.48 mmHg; and 6.00 mmHg, 95% CI 2.22 to 9.78 in men and women respectively) and DBP (3.29 mmHg, 95% CI 1.80 to 4.78; 5.35 mmHg, 95% CI 3.04 to 7.66). SA had lower SBP than EU(-4.57 mmHg, 95% CI -6.20 to -2.93; -2.97 mmHg, 95% CI -5.45 to -0.49) but similar DBP values. Meta-analysis by subgroup showed that SA originating from countries where Islam is the main religion had lower SBP and DBP values than EU. In multivariate meta-regression analyses, SBP difference between minorities and EU populations, was influenced by panethnicity and diabetes prevalence. Conclusions: 1) The higher BP in SSA is maintained over decades, suggesting limited efficacy of prevention strategies in such group in Europe;2) The lower BP in Muslim populations suggests that yet untapped lifestyle and behavioral habits may reveal advantages towards the development of hypertension;3) The additive effect of diabetes, emphasizes the need of new strategies for the control of hypertension in groups at high prevalence of diabetes. [ABSTRACT FROM AUTHOR]

Background: Although the large majority of persons with diabetes and other non-communicable diseases (NCDs) lives and dies in low- and middle-income countries, the prevention and treatment of diabetes and other NCDs is widely neglected in these areas. A contributing reason may be that, unlike the impacts of acute and communicable diseases, the demands on resources imposed by diabetes is not superficially obvious, and studies capable of detecting these impacts have not be done. Methods: To ascertain recent use of medical services and medicines and other information about the impact of ill-health, we in 2008–2009 conducted structured, personal interviews with 1,780 persons with diagnosed diabetes (DMs) and 1,770 matched comparison subjects (MCs) without diabetes in Cameroon, Mali, Tanzania and South Africa. We sampled DMs from diabetes registries and, in Cameroon and South Africa, from attendees at outpatient diabetes clinics. To recruit MCs, we asked subjects with diabetes to identify five persons living nearest to them who were of the same sex and approximate age. We estimated diabetes impact on medical services use by calculating ratios and differences between DMs and MCs, testing for statistical significance using two-stage multivariable hurdle models. Findings: DMs consumed 12.95 times more days of inpatient treatment, 7.54 times more outpatient visits, and 5.61 times more medications than MCs (all p<0.001). DMs used an estimated 3.44 inpatient days per person per year, made 10.72 outpatient visits per person per year (excluding traditional healers), and were taking an average of 2.49 prescribed medicines when interviewed. Conclusions: In Sub-Saharan Africa, the relative incremental use of medical care and medicines associated with diagnosed diabetes is much greater than in industrialized countries and in China. Published calculations of the health-system impact of diabetes in Africa are dramatic underestimates. Although non-communicable diseases like diabetes are commonly thought to be minor problems for health systems and patients in Africa, our data demonstrate the opposite. [ABSTRACT FROM AUTHOR]

The author explores the contributions of the African Programme for Onchocerciasis Control (APOC) for treating patients with onchocerciasis in 16 sub-Saharan countries including Cameroon, Congo and Ethiopia. Details on the updates health impact of the disease estimation based on disability weights from year 1995 to 2015 is discussed. The author also emphasizes the risk of skin disease in patients with onchocerciasis.

Background: Health inequities in developing countries are difficult to eradicate because of limited resources. The neglect of adult mortality in Sub-Saharan Africa (SSA) is a particular concern. Advances in data availability, software and analytic methods have created opportunities to address this challenge and tailor interventions to small areas. This study demonstrates how a generic framework can be applied to guide policy interventions to reduce adult mortality in high risk areas. The framework, therefore, incorporates the spatial clustering of adult mortality, estimates the impact of a range of determinants and quantifies the impact of their removal to ensure optimal returns on scarce resources. Methods: Data from a national cross-sectional survey in 2007 were used to illustrate the use of the generic framework for SSA and elsewhere. Adult mortality proportions were analyzed at four administrative levels and spatial analyses were used to identify areas with significant excess mortality. An ecological approach was then used to assess the relationship between mortality “hotspots” and various determinants. Population attributable fractions were calculated to quantify the reduction in mortality as a result of targeted removal of high-impact determinants. Results: Overall adult mortality rate was 145 per 10,000. Spatial disaggregation identified a highly non-random pattern and 67 significant high risk local municipalities were identified. The most prominent determinants of adult mortality included HIV antenatal sero-prevalence, low SES and lack of formal marital union status. The removal of the most attributable factors, based on local area prevalence, suggest that overall adult mortality could be potentially reduced by ∼90 deaths per 10,000. Conclusions: The innovative use of secondary data and advanced epidemiological techniques can be combined in a generic framework to identify and map mortality to the lowest administration level. The identification of high risk mortality determinants allows health authorities to tailor interventions at local level. This approach can be replicated elsewhere. [ABSTRACT FROM AUTHOR]

Malaria is a global health problem responsible for nearly one million deaths every year around 85% of which concern children younger than five years old in Sub-Saharan Africa. In addition, around million clinical cases are declared every year. The level of infection, expressed as parasite density, is classically defined as the number of asexual parasites relative to a microliter of blood. Microscopy of Giemsa-stained thick blood films is the gold standard for parasite enumeration. Parasite density estimation methods usually involve threshold values; either the number of white blood cells counted or the number of high power fields read. However, the statistical properties of parasite density estimators generated by these methods have largely been overlooked. Here, we studied the statistical properties (mean error, coefficient of variation, false negative rates) of parasite density estimators of commonly used threshold-based counting techniques depending on variable threshold values. We also assessed the influence of the thresholds on the cost-effectiveness of parasite density estimation methods. In addition, we gave more insights on the behavior of measurement errors according to varying threshold values, and on what should be the optimal threshold values that minimize this variability. [ABSTRACT FROM AUTHOR]