African Journal of Laboratory Medicine最新文献

Background: Despite the tremendous progress made in advancing laboratory medicine in low- and middle-income countries (LMICs), inadequate quality management systems (QMSs) remain a problem and barrier to provision of reliable laboratory services in resource-limited settings. Therefore, it is useful to study the experience of medical laboratories in LMICs that have successfully implemented QMS.

Aim: This review identified key success factors (KSFs) for medical laboratories in LMICs implementing QMS in accordance with the International Organization for Standardization standard 15189 as a pathway to improving laboratory quality.

Methods: Applying Preferred Reporting Items for Systematic Reviews procedures, we conducted a targeted search of studies from LMICs published between 2012 and 2022 to identify KSFs. Thirty-two out of 952 references retrieved were considered relevant and included in this review. Grounded theory was used to extract key features of the included studies to derive KSFs.

Results: Ten KSFs for medical laboratories striving to implement QMS were identified and described. These KSFs were integrated to create a model of success for laboratory QMS implementation. The model consists of three underlying factors, namely preparing for change, resource availability, and effective project management, each comprising three separate KSFs. Institutional commitment was identified as the core of the model and is integral to ensuring the quality of laboratory services.

Conclusion: Laboratories planning to implement a QMS can benefit from understanding the KSFs demonstrated in this study as this would help them to identify the necessary changes to implement and set realistic expectations about the outcomes of QMS implementation.

[This corrects the article DOI: 10.4102/ajlm.v11i1.1344.].

Background: Antimicrobial resistance (AMR) surveillance plays an important role in early detection of resistant strains of pathogens and informs treatments decisions at local, regional and national levels. In 2017, Tanzania developed a One Health AMR Surveillance Framework to guide establishment of AMR surveillance systems in the human and animal sectors.

Aim: We reviewed AMR surveillance studies in Tanzania to document progress towards establishing an AMR surveillance system and determine effective strengthening strategies.

Methods: We conducted a literature review on AMR studies conducted in Tanzania by searching Google Scholar, PubMed, and the websites of the Tanzania Ministry of Health and the World Health Organization for articles written in English and published from January 2012 to March 2021 using relevant search terms. Additionally, we reviewed applicable guidelines, plans, and reports from the Tanzanian Ministry of Health.

Results: We reviewed 10 articles on AMR in Tanzania, where studies were conducted at hospitals in seven of Tanzania's 26 regions between 2012 and 2019. Nine AMR sentinel sites had been established, and there was suitable and clear coordination under 'One Health'. However, sharing of surveillance data between sectors had yet to be strengthened. Most studies documented high resistance rates of Gram-negative bacteria to third-generation cephalosporins. There were few laboratory staff who were well trained on AMR.

Conclusion: Important progress has been made in establishing a useful, reliable AMR surveillance system. Challenges include a need to develop, implement and build investment case studies for the sustainability of AMR surveillance in Tanzania and ensure proper use of third-generation cephalosporins.

What this study adds: This article adds to the knowledge base of AMR trends in Tanzania and progress made in the implementation of AMR surveillance in human health sector as a contribution to the global AMR initiatives to reduce AMR burden worldwide. It has highlighted key gaps that need policy and implementation level attention.

Introduction: Liddle syndrome is an autosomal dominantly inherited disorder usually arising from single mutations of the genes that encode for the alpha, beta and gamma epithelial sodium channel (ENaC) subunits. This leads to refractory hypertension, hypokalaemia, metabolic alkalosis, hyporeninaemia and hypoaldosteronism, through over-activation of the ENaC.

Case presentation: We describe a 5-day old neonate who presented with severe hypernatraemic dehydration requiring admission to Steve Biko Academic Hospital in South Africa in 2012. Further evaluation revealed features in keeping with Liddle syndrome. Two compound heterozygous mutations located at different subunits encoding the ENaC were detected following genetic sequencing done in 2020. The severe clinical phenotype observed here could be attributed to the synergistic effect of these known pathological mutations, but may also indicate that one of the other variants detected has hitherto undocumented pathological effects.

Management and outcome: This child's treatment course was complicated by poor adherence to therapy, requiring numerous admissions over the years. Adequate blood pressure control was achieved only after the addition of amiloride at the end of 2018, which raised the suspicion of an ENaC abnormality.

Conclusion: To our knowledge, this is the first Liddle syndrome case where a combined effect from mutations resulted in severe disease. This highlights the importance of early recognition and management of this highly treatable genetic disease to prevent the grave sequelae associated with long-standing hypertension. Whole exome sequencing may assist in the detection of known mutations, but may also unveil new potentially pathological variants.

What this study adds: This study highlights the importance of developing a high index of suspicion of tubulopathy such as Liddle syndrome for any child presenting with persistent hypertension associated with hypokalaemic metabolic alkalosis.

Background: The parasite Schistosoma haematobium causes urogenital schistosomiasis, a chronic infectious disease that occurs mainly among school-age children.

Objective: The prevalence of S. haematobium infection and level of intensity relative to age, gender and status of selected serum micronutrients among school-age children were investigated in suburban communities in Bekwarra, Nigeria.

Methods: This cross-sectional school-based study randomly recruited 353 children aged between 4 and 16 years from five elementary schools between June 2019 and December 2019. We gathered socio-demographic data about each child using a semi-structured questionnaire. Blood samples were collected for micronutrient analysis and urine samples were collected for assessment of S. haematobium infection.

Results: A total of 57 (16.15%) school-age children were infected with S. haematobium. Girls (n = 34; 9.63%) were more frequently infected than boys (n = 23; 6.52%). Infection was most frequent among children aged 8-11 years (n = 32; 23.19%) and was significantly associated with age (p = 0.022) and gender (p < 0.001). Serum levels of iron, calcium, copper and zinc among infected children were significantly lower than those of non-infected children. Intensity of infection was negatively associated with iron (r = -0.21), calcium (r = -0.24), copper (r = -0.61; p < 0.001) and zinc (r = -0.41; p < 0.002).

Conclusion: This study showed that S. haematobium infection adversely impacted the micronutrient status of school-age children in suburban Nigeria. Measures to lower the prevalence of schistosomiasis among school-age children, including efficient drug distribution, education campaigns and community engagement, are necessary.

What this study adds: This research emphasises the significance of implementing infection prevention and control interventions to mitigate the transmission and prevalence of schistosomiasis among school age children.

Inborn errors of metabolism (IEM) are a group of genetically derived diseases that are individually rare but collectively common and can be very severe. While high-income countries usually employ modern scientific technologies like tandem mass spectrometry for IEM investigation, these disorders are, in contrast, only rarely screened for in developing countries due to misconceptions that the required facilities are beyond the reach of these countries. This paper attempts to educate scientists and clinicians in developing countries on low-technology IEM screening methods that only require moderate facilities. Although a definitive diagnosis of IEM may require specialised laboratory investigations and attendant interpretation, in most cases, the basic facilities available in the average clinical chemistry laboratory in developing countries can allow the early detection of IEM. This early detection would facilitate critical early decision making, thus leading to better management, optimised treatment, and reduced morbidity and or mortality of IEM in these resource-limited countries. With this approach, a few referral centres for confirmatory investigation, comparable to those existing in developed countries, could be established. This can be integrated into creative health education for healthcare professionals and families who have individuals with IEM.

What this study adds: IEMs are important enough that every country, developed or developing, should have screening plans and basic laboratory facilities that are adequate for initial IEM diagnosis. No country should therefore give up on testing for IEMs on the excuse of a paucity of advanced facilities.

Background: The National Health Laboratory Service is mandated to deliver cost-effective and efficient diagnostic services across South Africa. Their mandate is achieved by a network of laboratories ranging from centralised national laboratories to distant rural facilities.

Objective: This study aimed to establish a model of CD4 reagent utilisation as an independent measure of laboratory efficiency.

Methods: The efficiency percentage was defined as finished goods (number of reportable results) over raw materials (number of reagents supplied) for 47 laboratories in nine provinces (both anonymised) for 2019. The efficiency percentage at national and provincial levels was calculated and compared to the optimal efficiency percentage derived using pre-set assumptions. Comparative laboratory analysis was conducted for the provinces with the best and worst efficiency percentages. The possible linear relationship between the efficiency percentage and call-outs, days lost, referrals, and turn-around time was assessed.

Results: Data are reported for 2 806 799 CD4 tests, with an overall efficiency percentage of 84.5% (optimal of 84.98%). The efficiency percentage varied between 75.7% and 87.7% between provinces, while within the laboratory it ranged from 66.1% to 111.5%. Four laboratories reported an efficiency percentage ranging from 67.8% to 85.7%. No linear correlation was noted between the efficiency percentage, call-outs, days lost, and turn-around time performance.

Conclusion: Reagent efficiency percentage distinguished laboratories into different utilisation levels irrespective of their CD4 service level. This parameter is an additional independent indicator of laboratory performance, with no relationship with any contributing factors tested, that can be implemented across pathology disciplines for monitoring reagent utilisation.

What this study adds: This study provides an objective methodology to assess reagent utilisation as an independent measure of laboratory efficiency. This model could be applied to all routine pathology services.

Background: KwaZulu-Natal ranked second highest among South African provinces for the number of laboratory-confirmed cases during the second wave of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. The seroprevalence of SARS-CoV-2 among certain vulnerable groups, such as people living with HIV in KwaZulu-Natal, is unknown.

Objective: The study aimed to determine the prevalence of SARS-CoV-2 immunoglobulin G (IgG) in HIV-positive versus HIV-negative patients.

Methods: This was a retrospective analysis of residual clinical blood specimens unrelated to coronavirus disease 2019 (COVID-19) submitted for diagnostic testing at Inkosi Albert Luthuli Central Hospital, Durban, from 10 November 2020 to 09 February 2021. Specimens were tested for SARS-CoV-2 immunoglobulin G on the Abbott Architect analyser.

Results: A total of 1977/8829 (22.4%) specimens were positive for SARS-CoV-2 antibodies. Seroprevalence varied between health districts from 16.4% to 37.3%, and was 19% in HIV-positive and 35.3% in HIV-negative specimens. Seroprevalence was higher among female patients (23.6% vs 19.8%; p < 0.0001) and increased with increasing age, with a statistically significant difference between the farthest age groups (< 10 years and > 79 years; p < 0.0001). The seroprevalence increased from 17% on 10 November 2020 to 43% on 09 February 2021 during the second wave.

Conclusion: Our results highlight that during the second COVID-19 wave in KwaZulu-Natal a large proportion of people living with HIV were still immunologically susceptible. The reduced seropositivity in people with virological failure further emphasises the importance of targeted vaccination and vaccine response monitoring in these individuals.

What the study adds: This study contributes to data on SARS-CoV-2 seroprevalence before and during the second wave in KwaZulu-Natal, South Africa, which has the highest HIV prevalence globally. Reduced seropositivity was found among people living with HIV with virological failure, highlighting the importance of targeted booster vaccination and vaccine response monitoring.

Background: Autoantibodies are vital biomarkers for the diagnosis, assessment and prognostic determination of various autoimmune disorders.

Objective: This study aimed to evaluate the performance of the two AtheNA Multi-Lyte^® systems for the detection of various autoantibodies.

Methods: A total of 105 systemic lupus erythematosus patients, 35 patients with other autoimmune diseases (diseased controls), and 30 healthy volunteers (healthy controls) at Zagazig University Hospitals, Zagazig city, Al Sharqia governorate were tested for anti-double-stranded DNA (anti-dsDNA) antibodies using indirect immunofluorescence (IIF) and the AtheNA Multi-Lyte^® anti-nuclear antibodies-II system between May 2020 and April 2022. Seventy-five patients with clinically suspected autoimmune vasculitis (AIV) and 25 healthy volunteers were also tested for anti-myeloperoxidase and anti-proteinase 3 antibodies using IIF, the AtheNA Multi-Lyte^® AIV system, and enzyme-linked immunosorbent assay (ELISA).

Results: The AtheNA anti-dsDNA test (98.5%) was more specific than IIF (96.9%) for diagnosing systemic lupus erythematosus, but both tests had the same sensitivity (38.1%). Combining both methods increased sensitivity to 47.6%, while increasing the cut-off of the AtheNA anti-dsDNA test to 134 international units/mL increased specificity to 100%. The AtheNA Multi-Lyte AIV system exhibited substantial agreement with IIF regarding anti-myeloperoxidase testing (κ = 0.65) and almost perfect agreement with ELISA (κ = 0.85). The AtheNA Multi-Lyte^® AIV system exhibited perfect agreement with IIF (κ = 1) and substantial agreement with ELISA for anti-proteinase 3 testing (κ = 0.63).

Conclusion: AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

What this study adds: It is necessary to evaluate various autoantibodies detection assays to increase both sensitivity and specificity of autoimmune diseases diagnostic approaches. AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

Background: Sepsis is characterised by multi-organ failure due to an uncontrolled immune response to infection. Sepsis prevalence is increased in developing countries and requires prompt diagnosis and treatment. Reports, although controversial, suggest that full blood count parameters and cell ratios could assist in the early screening for sepsis.

Objective: The study evaluated the use of haematological cell ratios in screening for sepsis in a South African population.

Methods: The study retrospectively analysed the complete blood counts, blood cultures (BC) and biochemical test results of 125 adult patients who presented between January 2021 and July 2021 at a hospital in Cape Town. An ISO15189-accredited laboratory performed all of the tests. We compared and correlated the automated differential counts, neutrophil, monocyte and platelet-to-lymphocyte ratios with procalcitonin levels. A p-value of < 0.05 was considered significant.

Results: Sixty-two sepsis patients (procalcitonin > 2 ng/L and positive BC) were identified and compared to 63 non-sepsis controls. All cell ratios were significantly elevated in sepsis patients (p < 0.001). However, the two groups had no significant difference in absolute monocyte counts (p = 0.377). In addition, no correlation was detected between any cell ratios and procalcitonin.

Conclusion: In combination with complete blood count parameters, haematology cell ratios can be used for early sepsis detection. The full blood count is widely available, inexpensive, and routinely requested by emergency care clinicians. Although procalcitonin and BC remain the gold standard, the calculation of cell ratios could provide a simple screening tool for the early detection of sepsis.

What this study adds: This study adds evidence to the proposal that calculating haematological cell ratios assists in the early screening of sepsis in a South African setting.