Prevalence and trends of hepatitis B and C virus biomarkers in Zimbabwe: comparative analyses of a nation's blood-donor surveillance data and meta-analyses of population studies.

BACKGROUND: The disproportionate burden of viral hepatitis, particularly hepatitis B virus (HBV) is experienced by people living in low-resourced sub-Saharan Africa, where the estimated prevalence is 3-7 times the global average. Therefore to inform policy, we describe the seroprevalence and trends of hepatitis C (HCV) and HBV biomarkers: anti-HCV antibody and hepatitis B surface antigen (HBsAg), respectively, in Zimbabwe. METHODS: We analysed data from 181,248 consecutive blood-donors, examined between January 2015 through December 2018. Additionally, we conducted a comprehensive literature review using PubMed and African Journals Online databases, meta-analysing selected papers from Zimbabwe, published between 1970 and 2020, that met specific criteria. RESULTS: Overall age-standardized prevalence rate (ASPR) for anti-HCV was 8.67 (95%CI, 0.25-17.09) per 100,000, while that for HBsAg was 2.26 (95%, 1.89-2.63) per 1000 blood-donors, per year. Meta-analysis of 9 studies comprising 220,127 persons tested for anti-HCV revealed ASPR of 0.05% (95% 0%-0.19%) in blood-donors and 1.78% (95%CI, 0.01%-5.55%) in the general population, for an overall pooled ASPR of 0.44 (95%CI, 0.19%-0.76%). 21 studies comprising 291,784 persons tested for HBsAg revealed ASPR of 0.65% (95%CI, 0.31%-1.00%) in blood-donors and 4.31% (95%CI, 1.77%-6.50%) in the general population for an overall pooled ASPR of 4.02% (95%CI, 3.55%-4.48%), after HBV vaccine introduction. HBsAg prevalence was significantly higher before HBV vaccine introductions. CONCLUSIONS: The prevalence of HBV is decreasing, consistent with the introduction of HBV vaccination, while HCV prevalence is increasing in Zimbabwe. This highlights the need for Improved blood-donor screening and more informative biomarker studies, particularly among repeat donors and children.

Estimating spatially disaggregated probability of severe COVID-19 and the impact of handwashing interventions: The case of Zimbabwe.

INTRODUCTION: The severity of COVID-19 disease varies substantially between individuals, with some infections being asymptomatic while others are fatal. Several risk factors have been identified that affect the progression of SARS-CoV-2 to severe COVID-19. They include age, smoking and presence of underlying comorbidities such as respiratory illness, HIV, anemia and obesity. Given that respiratory illness is one such comorbidity and is affected by hand hygiene, it is plausible that improving access to handwashing could lower the risk of severe COVID-19 among a population. In this paper, we estimate the potential impact of improved access to handwashing on the risk of respiratory illness and its knock-on impact on the risk of developing severe COVID-19 disease across Zimbabwe. METHODS: Spatial generalized additive models were applied to cluster level data from the 2015 Demographic and Health Survey. These models were used to generate continuous (1km resolution) estimates of risk factors for severe COVID-19, including prevalence of major comorbidities (respiratory illness, HIV without viral load suppression, anemia and obesity) and prevalence of smoking, which were aggregated to district level alongside estimates of the proportion of the population under 50 from Worldpop data. The risk of severe COVID-19 was then calculated for each district using published estimates of the relationship between comorbidities, smoking and age (under 50) and severe COVID-19. Two scenarios were then simulated to see how changing access to handwashing facilities could have knock on implications for the prevalence of severe COVID-19 in the population. RESULTS: This modeling conducted in this study shows that (1) current risk of severe disease is heterogeneous across the country, due to differences in individual characteristics and household conditions and (2) that if the quantifiable estimates on the importance of handwashing for transmission are sound, then improvements in handwashing access could lead to reductions in the risk of severe COVID-19 of up to 16% from the estimated current levels across all districts. CONCLUSIONS: Taken alongside the likely impact on transmission of SARS-CoV-2 itself, as well as countless other pathogens, this result adds further support for the expansion of access to handwashing across the country. It also highlights the spatial differences in risk of severe COVID-19, and thus the opportunity for better planning to focus limited resources in high-risk areas in order to potentially reduce the number of severe cases.

Transfusion medicine research in Africa: Insights from investigators in the field.

BACKGROUND AND OBJECTIVES: Research in low-resource settings is inherently challenging. We sought to assess the factors that have impeded or facilitated transfusion medicine (TM) research in various African settings. MATERIALS AND METHODS: A qualitative case study was conducted of selected investigators in Africa; selection was based on productivity-spanning publication, leadership and research in TM. We designed a questionnaire to explore the factors impeding or facilitating TM research to understand the impact on the investigators' careers. Written responses were independently coded and double-checked for precision. Qualitative analysis was conducted, whereby responses were grouped thematically and clustered by relationship. The initial findings were discussed with respondents to validate and refine the interpretations. The recorded transcript was analysed and incorporated into the final analysis. RESULTS: Six investigators participated in the study. Their responses yielded 471 coded comments: 389 from the questionnaires and 82 from the ensuing discussion. The most frequently cited factors described included knowledge and intellectual abilities (n = 104), personal effectiveness (n = 99), research and governance structure (n = 97), and engagement, influence and impact (n = 75). Four relationship clusters emerged from the facilitators (n = 42), barriers (n = 28), and common approaches (n = 26) to research, informing summary themes of adaptation, collaboration, perseverance, and resiliency. CONCLUSION: Individual attributes were found to be central to a successful TM research career in African settings. However, given other public health priorities and constraints, interpersonal relationships, organizational structures and the broader research context were important to TM researchers. Overcoming complexities demands adaptation, collaboration, perseverance and resiliency.

Transfusion research priorities for blood services in sub-Saharan Africa.

Evidence to support many blood transfusion policies and practices in sub-Saharan Africa (SSA) is weak or lacking. SSA cannot extrapolate from wealthy countries' research findings because its environment, users and structures are very different and SSA has critical blood shortages. SSA needs to generate its own evidence but research funds are very scarce and need to be carefully targeted to match need. This study aimed to define this need by determining research priorities for blood services in SSA. Thirty-five stakeholders representing diverse blood services' interests and expertise participated in a workshop. An adapted 'consensus development method' was used to identify, agree and justify research priorities under five themes through small group and plenary discussion, and cumulative voting. Research priorities covered traditional research areas, such as clinical use of blood and infection screening, but also highlighted many new, under-researched topics, mostly concerning blood service 'systems', such as economics, blood components and regulation. Lack of electronic information management systems was an important hindrance to the blood services' ability to generate robust research data. This study has identified and prioritised novel research that will help blood services in SSA to address their own needs including their most urgent problem: the lack of access to adequate blood supplies. To catalyse this research blood services in SSA need to enhance their capacity to conduct, commission and manage research and to strengthen their collaborations within and beyond Africa.

Cost effectiveness of adding nucleic acid testing to hepatitis B, hepatitis C, and human immunodeficiency virus screening of blood donations in Zimbabwe.

BACKGROUND: The aim of this study was to assess the cost effectiveness of introducing individual-donation nucleic acid testing (ID-NAT), in addition to serologic tests, compared with the exclusive use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) I and II among blood donors in Zimbabwe. STUDY DESIGN AND METHODS: The costs, health consequences, and cost effectiveness of adding ID-NAT to serologic tests, compared with serologic testing alone, were estimated from a health care perspective using a decision-analytic model. RESULTS: The introduction of ID-NAT in addition to serologic tests would lower the risk of HBV, HCV, and HIV transmission to 46.9, 0.3, and 2.7 per 100,000 donations, respectively. ID-NAT would prevent an estimated 25, 6, and 9 HBV, HCV, and HIV transfusion-transmitted infections per 100,000 donations, respectively. The introduction of this intervention would result in an estimated 212 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio is estimated at US$17,774/QALY, a value far more than three times the gross national income per capita for Zimbabwe. CONCLUSION: Although the introduction of NAT could further improve the safety of the blood supply, current evidence suggests that it cannot be considered cost effective. Reducing the test costs for NAT through efficient donor recruitment, negotiating the price of reagents, and the efficient use of technology will improve cost effectiveness.

Modelling the risk of transfusion transmission from travelling donors.

BACKGROUND: The EUFRAT (European Up-Front Risk Assessment Tool) was developed as an online risk assessment tool ( http://eufrattool.ecdc.europa.eu ) to help decision-makers assess the transmission risk of emerging infectious diseases (EID) through blood transfusion. The aim of this study is to extend the methodology developed in the EUFRAT project to quantify the transfusion transmission (TT) risk from travelling donors. METHODS: A generic model for estimating the TT risk from a group of travelling donors that visited an EID risk area was developed. In addition, the new model distinguishes projected future transmissions from those that have already occurred. As an illustration the model was applied to the outbreaks of chikungunya in Italy in 2007 and Q fever in the Netherlands in 2007-2009. RESULTS: Formulas for calculating the travelling donors' TT risk were derived. For the chikungunya outbreak in Italy an early intervention (at the end of week 7 after the start of the outbreak, so after only 19% of all cases) would have been required to prevent only 41% of all expected transmissions at that time. For Q fever, in which the transmission of chronic Q fever is considered, even at the end of the third annual outbreak's peak 47% of all (chronic) Q fever transmissions could still be prevented. CONCLUSIONS: The updated model allows estimation of the infection transmission risk from travelling donors. In combination with the distinction between past and future transmissions, these estimates provide valuable information to support decisions concerning communication with the public and/or the implementation of safety interventions.

Impact of using different blood donor subpopulations and models on the estimation of transfusion transmission residual risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in Zimbabwe.

BACKGROUND: Various models for estimating the residual risk (RR) of transmission of infections by blood transfusion have been published mainly based on data from high-income countries. However, to obtain the data required for such an assessment remains challenging for most developing settings. The National Blood Service Zimbabwe (NBSZ) adapted a published incidence-window period (IWP) model, which has less demanding data requirements. In this study we assess the impact of various definitions of blood donor subpopulations and models on RR estimates. We compared the outcomes of two published models and an adapted NBSZ model. STUDY DESIGN AND METHODS: The Schreiber IWP model (Model 1), an amended version (Model 2), and an adapted NBSZ model (Model 3) were applied. Variably the three models include prevalence, incidence, preseroconversion intervals, mean lifetime risk, and person-years at risk. Annual mean RR estimates and 95% confidence intervals for each of the three models for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) were determined using NBSZ blood donor data from 2002 through 2011. RESULTS: The annual mean RR estimates for Models 1 through 3 were 1 in 6542, 5805, and 6418, respectively for HIV; 1 in 1978, 2027, and 1628 for HBV; and 1 in 9588, 15,126, and 7750, for HCV. CONCLUSIONS: The adapted NBSZ model provided comparable results to the published methods and these highlight the high occurrence of HBV in Zimbabwe. The adapted NBSZ model could be used as an alternative to estimate RRs when in settings where two repeat donations are not available.

Within-Gender Changes in HIV Prevalence among Adults between 2005/6 and 2010/11 in Zimbabwe.

INTRODUCTION: Zimbabwe has reported significant declines in HIV prevalence between 2005/06 and 2010/11 Demography and Health Surveys; a within-gender analysis to identify the magnitude and factors associated with this change, which can be masked, is critical for targeting interventions. METHODS: We analyzed change in HIV prevalence for 6,947 women and 5,848 men in the 2005/06 survey and 7,313 women and 6,250 men in 2010/11 surveys using 2005/06 as referent. The data was analyzed taking into consideration the survey design and therefore the svy, mean command in Stata was used in both linear and logistic regression. RESULTS: There were similar proportional declines in prevalence at national level for males (15% p=0.011) and females (16%,p=0.008). However, there were variations in decline by provincial setting, demographic variables of age, educational level and some sexual risk behaviours. In logistic regression analysis, statistically significant declines were observed among men in Manicaland, Mashonaland East and Harare (p<0.01) and for women in Manicaland, Mashonaland Central and Harare (p<0.01). Although not statistically significant, numerical increases were observed among men in Matebeleland North, Matebeleland South, Midlands and for both men and women in Bulawayo. Young women in the age range 15-34 experienced a decline in prevalence (p<0.01) while older men 30-44 had a statistically significant decline (p<0.01). Having a secondary and above education, regardless of employment status for both men and women recorded a significant decline. For sexual risk behaviours, currently in union for men and women and not in union for women there was a significant decline in prevalence. CONCLUSION: Zimbabwe has reported a significant decline among both men and women but there are important differentials across provinces, demographic characteristics and sexual risk behaviours that suggest that the epidemic in Zimbabwe is heterogeneous and therefore interventions must be targeted in order to achieve epidemic control.

Human immunodeficiency virus prevalence, incidence, and residual transmission risk in first-time and repeat blood donations in Zimbabwe: implications on blood safety.

BACKGROUND: National Blood Service Zimbabwe human immunodeficiency virus (HIV) risk management strategy includes screening and discarding of first-time donations, which are collected in blood packs without an anticoagulant (dry pack). To evaluate the impact of discarding first-time donations on blood safety the HIV prevalence, incidence, and residual risk in first-time and repeat donations (wet packs) were compared. STUDY DESIGN AND METHODS: Donor data from 2002 to 2010 were retrieved from a centralized national electronic donor database and retrospectively analyzed. Chi-square test was used to compare HIV prevalence with relative risk (RR), and the RR point estimates and 95% confidence interval (CI) are reported. Trend analysis was done using Cochran-Armitage trend test. HIV residual risk estimates were determined using published residual risk estimation models. RESULTS: Over the 9 years the overall HIV prevalence estimates are 1.29% (n = 116,058) and 0.42% (n = 434,695) for first-time and repeat donations, respectively. The overall RR was 3.1 (95% CI, 2.9-3.3; p < 0.0001). The overall mean residual transmission risk of HIV window phase donations in first-time was 1:7384 (range, 1:11,308-1:5356) and in repeat donors it was 1:5496 (range, 1:9943-1:3347). CONCLUSION: The significantly high HIV prevalence estimates recorded in first-time over repeat donations is indicative of the effectiveness of the HIV risk management strategy. However, comparable residual transmission risk estimates in first-time and repeat donors point to the need to further review the risk management strategies. Given the potential wastage of valuable resources, future studies should focus on the cost-effectiveness and utility of screening and discarding first-time donations.