African Journal of Laboratory Medicine最新文献

{"title":"Comparison of commercial assays and two-step approach to detect <i>Clostridioides difficile</i> in South Africa.","authors":"Sarishna Singh,&nbsp;Mae Newton-Foot,&nbsp;Pieter Nel,&nbsp;Colette Pienaar","doi":"10.4102/ajlm.v11i1.1809","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1809","url":null,"abstract":"<p><strong>Background: </strong><i>Clostridioides difficile</i> is the number one cause of hospital-acquired diarrhoea. Accurate diagnosis of <i>C. difficile</i> is of utmost importance as it guides patient management and infection control practices. Studies evaluating the performance of commercially available nucleic acid amplification tests (NAATs) versus algorithms are lacking in resource-limited settings.</p><p><strong>Objective: </strong>This study assessed the performance of three commercially available tests and a two-step approach for the diagnosis of <i>C. difficile</i> infection using toxigenic culture (TC) as the gold standard.</p><p><strong>Methods: </strong>Two hundred and twenty-three non-duplicate loose stool samples were submitted to the National Health Laboratory Service Microbiology Laboratory at Tygerberg Hospital, Cape Town, South Africa, from October 2017 to October 2018. The samples were tested in parallel using the <i>C. DIFF QUIK CHEK COMPLETE</i> enzyme immunoassay (EIA) and two NAATs (Xpert <i>C. difficile</i> and BD MAX Cdiff), and the results were compared to TC. The performance of a two-step approach consisting of the <i>C. DIFF QUIK CHEK COMPLETE</i> followed by the Xpert <i>C. difficile</i> was also determined.</p><p><strong>Results: </strong>Of 223 faecal specimens tested, 37 (16.6%) were TC-positive. The sensitivity and specificity of the <i>C. DIFF QUIK CHEK COMPLETE</i> were 54.1% and 98.9%; Xpert <i>C. difficile</i>, 86.4% and 96.8%; BD MAX Cdiff, 89.2% and 96.8%; and two-step approach, 89.2% and 96.2%.</p><p><strong>Conclusion: </strong>The <i>C. DIFF QUIK CHEK COMPLETE</i>, in a two-step approach with the Xpert <i>C. difficile</i>, performed similarly to the NAATs on their own and offer advantages in terms of cost and workflow in low-resource settings.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1809"},"PeriodicalIF":1.1,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575369/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40574373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Audit of amylase and lipase requests in suspected acute pancreatitis and cost implications, South Africa.","authors":"Annie E Cook,&nbsp;Thumeka P Jalavu,&nbsp;Annalise E Zemlin","doi":"10.4102/ajlm.v11i1.1834","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1834","url":null,"abstract":"<p><strong>Background: </strong>The internationally accepted criteria for the diagnosis of acute pancreatitis (AP) requires two of the three following features to be present: characteristic abdominal pain, elevated serum amylase and/or lipase enzymes, or consistent imaging results. However, sensitivity and specificity can vary depending on the population and cut-off values used.</p><p><strong>Objective: </strong>This study evaluated the suitability of amylase and lipase as first-line diagnostic biomarkers of suspected AP for the local population served by Tygerberg Hospital, South Africa.</p><p><strong>Methods: </strong>This retrospective analysis was conducted in June 2019 using all amylase and/or lipase request data from December 2018. Patient clinical data were included in sensitivity and specificity analyses of amylase, lipase or dual requests for diagnosis of AP. Cost per test data were obtained from the National Health Laboratory Service and used to calculate the total cost of the tests and potential savings.</p><p><strong>Results: </strong>Sensitivity for lipase was 90.0% compared to 50.0% for amylase. Specificity was similar for singular measurements of lipase and amylase. Dual measurement of amylase and lipase showed no improvement in sensitivity (83.3%) and only a minor increase in specificity (97.4%) compared with measurement of lipase alone. The estimated savings was R2522.85 ($174.98 USD), with a potential annual cost saving of R84 423.74 ($5855.69 USD).</p><p><strong>Conclusion: </strong>Lipase was shown to be a more sensitive biomarker compared to amylase for the screening of AP, providing evidence for laboratories to educate local staff and promote improved requesting practices by clinicians. Additionally, preventing unnecessary dual requests may reduce costs.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1834"},"PeriodicalIF":1.1,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575380/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40559152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Red blood cell alloimmunisation in multi-transfused patients from an haemodialysis service in Burkina Faso.","authors":"Koumpingnin Nebie,&nbsp;Salam Sawadogo,&nbsp;Salifo Sawadogo,&nbsp;Jérôme Koulidiati,&nbsp;Habi Y A Lengani,&nbsp;Abdoul G Sawadogo,&nbsp;Jérôme Babinet,&nbsp;Mohammed Khalloufi,&nbsp;Saliou Diop,&nbsp;Eléonore Kafando","doi":"10.4102/ajlm.v11i1.1625","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1625","url":null,"abstract":"<p><strong>Background: </strong>In Burkina Faso, red blood cell (RBC) transfusion remains the crucial anaemia treatment following chronic renal failure (CRF) as erythropoietin and its analogues are unavailable. However, blood group matching beyond the ABO and Rhesus is not common in Burkina Faso. Thus, alloimmunisation is a potential issue for transfused patients.</p><p><strong>Objective: </strong>Our study aimed to identify anti-erythrocyte antibodies in multi-transfused CRF patients at the Yalgado Ouedraogo Teaching Hospital, Ouagadougou, Burkina Faso.</p><p><strong>Methods: </strong>This cross-sectional study, conducted from October 2018 to November 2019, included CRF patients who had received at least two RBC units. We screened patients for the presence of RBC antibodies using three commercial Cells panels and identified antibody specificities for positive screenings using 11 Cells panels for an indirect antiglobulin test (IAT) in a low ionic strength microcolumn gel-card system.</p><p><strong>Results: </strong>Two hundred and thirty-five patients (45.1% female; average age: 41.5 years) were included. The median number of blood units received per patient was 10 (interquartile range: 5-20). The overall alloimmunisation rate was 5.9% (14/235). Antibodies identified included: anti-D (1 case), anti-C (1 case), anti-D+C (4 cases), anti-C^W (1 case), anti-E (1 case), anti-S (1 case) and anti-Le^a (1 case). In four positive patients, the specificity of the antibodies was indeterminate. No risk factors were associated with alloimmunisation.</p><p><strong>Conclusion: </strong>In Burkina Faso, screening for RBC alloantibodies should be mandated for patients at risk. The high rate of indeterminate antibodies suggests the need to develop a local RBC antibody panel adapted to the local population.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1625"},"PeriodicalIF":1.1,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575384/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40559155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Human herpes virus type-6 is associated with central nervous system infections in children in Sudan.","authors":"Nada A Abdelrahim,&nbsp;Nahla Mohamed,&nbsp;Magnus Evander,&nbsp;Clas Ahlm,&nbsp;Imad M Fadl-Elmula","doi":"10.4102/ajlm.v11i1.1718","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1718","url":null,"abstract":"<p><strong>Background: </strong>Human herpes virus type-6 (HHV-6) is increasingly recognised as a febrile agent in children. However, less is known in sub-Saharan African countries, including Sudan.</p><p><strong>Objective: </strong>We investigated the involvement of HHV-6 in paediatric central nervous system (CNS) infections in Khartoum, Sudan.</p><p><strong>Methods: </strong>Febrile patients aged up to 15 years with suspected CNS infections at Omdurman Hospital for Children from 01 December 2009 to 01 August 2010 were included. Viral DNA was extracted from leftover cerebrospinal fluid (CSF) specimens and quantitatively amplified by real-time polymerase chain reaction (PCR) at Umeå University in Sweden.</p><p><strong>Results: </strong>Of 503 CSF specimens, 13 (2.6%) were positive for HHV-6 (33.0% [13/40 of cases with proven infectious meningitis]). The median thermal cycle threshold for all HHV-6-positive specimens was 38 (range: 31.9-40.8). The median number of virus copies was 281.3/PCR run (1 × 10⁵ copies/mL CSF; range: 30-44 × 10³ copies/PCR run [12 × 10³ - 18 × 10⁶ copies/mL CSF]). All positive patients presented with fever and vomiting; 86.0% had seizures. The male-to-female ratio was 1:1; 50.0% were toddlers, 42.0% infants and 8.0% teenagers. Most (83.0%) were admitted in the dry season and 17.0% in the rainy season. Cerebrospinal fluid leukocytosis was seen in 33.0%, CSF glucose levels were normal in 86.0% and low in 14.0%, and CSF protein levels were low in 14.0% and high in 43.0%.</p><p><strong>Conclusion: </strong>Among children in Sudan with CNS infections, HHV-6 is common. Studies on the existence and spread of HHV-6 chromosomal integration in this population are needed.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1718"},"PeriodicalIF":1.1,"publicationDate":"2022-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9575351/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40559154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Antimicrobial Resistance and Use Surveillance System on the African continent: Early implementation 2017-2019.","authors":"Barbara Tornimbene, Sergey Eremin, Reuben Abednego, Elamin O Abualas, Ilhem Boutiba, Abiodun Egwuenu, Walter Fuller, Laetitia Gahimbare, Susan Githii, Watipaso Kasambara, Chileshe Lukwesa-Musyani, Fidy A Miamina, Sekesai Mtapuri-Zinyowera, Grace Najjuka, Olga Perovic, Bassem Zayed, Yahaya A Ahmed, Maha T Ismail, Carmem L Pessoa da Silva","doi":"10.4102/ajlm.v11i1.1594","DOIUrl":"10.4102/ajlm.v11i1.1594","url":null,"abstract":"<p><strong>Background: </strong>Antimicrobial resistance (AMR) is becoming a critical public health issue globally. The World Health Organization launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) to support the strengthening of the AMR evidence base.</p><p><strong>Objective: </strong>The article describes the evolution of national AMR surveillance systems and AMR data reporting of countries in the African continent between 2017 and 2019, and the constraints, perceived impact and value of the participation in GLASS.</p><p><strong>Methods: </strong>Data on implementation of national surveillance systems and AMR rates were submitted to GLASS between 2017 and 2019 and summarised though descriptive statistics. The information on constraints and perceived impact and value in GLASS participation was collected though a set of questionnaires.</p><p><strong>Results: </strong>Between 2017 and 2019, Egypt, Ethiopia, Madagascar, Malawi, Mali, Mozambique, Nigeria, South Africa, Sudan, Tunisia, Uganda and Zambia submitted data to GLASS. The main constraints listed are linked to scarce laboratory capacity and capability, limited staffing, budget issues, and data management. Moreover, while the data are not yet nationally representative, high resistance rates were reported to commonly-used antibiotics, as the emerging resistance to last treatment options.</p><p><strong>Conclusion: </strong>Despite the limitations, more and more countries in the African continent are working towards reaching a status that will enable them to report AMR data in a complete and systematic manner. Future improvements involve the expansion of routine surveillance capacity for several countries and the implementation of surveys that allow to effectively define the magnitude of AMR in the continent.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1594"},"PeriodicalIF":1.0,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9453120/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33459937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuberculosis-loop-mediated isothermal amplification implementation in Cameroon: Challenges, lessons learned and recommendations.","authors":"Valerie F Donkeng-Donfack,&nbsp;Suzanne M Ongoulal,&nbsp;Yvonne J Djieugoue,&nbsp;Yannick Kamdem Simo,&nbsp;Henri Manga,&nbsp;Danielle A D Tollo,&nbsp;Edwige M A Belinga,&nbsp;Vincent Mbassa,&nbsp;Jean L Abena,&nbsp;Sara Eyangoh","doi":"10.4102/ajlm.v11i1.1792","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1792","url":null,"abstract":"<p><strong>Background: </strong>Until 2016, microscopy was the main tool for the early detection of pulmonary tuberculosis in Cameroon, especially in remote settings. Due to the poor sensitivity of microscopy, there was a need to implement a molecular assay in order to improve tuberculosis case detection.</p><p><strong>Intervention: </strong>In 2017, tuberculosis loop-mediated isothermal amplification (TB-LAMP), a molecular rapid diagnostic test recommended by the World Health Organization, was implemented in Cameroon as a replacement test of microscopy for initial diagnosis of pulmonary tuberculosis and also as a follow-on test to microscopy for smear-negative sputum specimens. A roll out plan for TB-LAMP implementation in Cameroon had been developed from January 2017 to April 2017, followed by initial implementation at four sites in May 2017. Additional sites were added progressively.</p><p><strong>Lessons learnt: </strong>The use of TB-LAMP as a follow-on test to microscopy for smear-negative sputum specimens helped in the detection of tuberculosis in 14.77% of those who were sputum-smear negative in 2019. Tuberculosis-loop-mediated isothermal amplification usage as an initial test, followed by testing with Xpert MTB/RIF for rapid tuberculosis and rifampicin resistance detection during tuberculosis mass screening campaigns, reduced the turn-around time by 73.23% as compared to when the Gene Xpert instrument was used alone.</p><p><strong>Recommendations: </strong>The implementation and scaling up of TB-LAMP in Cameroon contributed to increase access to tuberculosis molecular diagnosis in remote settings and as such improved tuberculosis case notification. However, to better enhance this notification and optimise the use of a TB-LAMP instrument, a suitable sample transport system is recommended.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1792"},"PeriodicalIF":1.1,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9453169/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33459932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacteriological profile and antibiogram of blood culture isolates from bloodstream infections in a rural tertiary hospital in Nigeria.","authors":"Oluwalana T Oyekale,&nbsp;Bola O Ojo,&nbsp;Adewale T Olajide,&nbsp;Oluwatoyin I Oyekale","doi":"10.4102/ajlm.v11i1.1807","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1807","url":null,"abstract":"<p><strong>Background: </strong>Bloodstream infections (BSIs) are a cause of significant morbidity and mortality requiring urgent antibiotic treatment. However, there is widespread antibiotic-resistance from the bacterial causes, necessitating regular surveillance for drug-resistant bacteria and their antibiograms.</p><p><strong>Objective: </strong>This study isolated and identified various bacterial causes of BSIs, determined their antibiotic susceptibility patterns, and determined the best empirical treatment for cases of BSI in the setting.</p><p><strong>Methods: </strong>A cross-sectional study was carried out at the Federal Teaching Hospital, Ido-Ekiti, Nigeria between June 2020 and February 2021 on 177 blood culture samples from cases of BSI. Identification of isolated bacteria and antibiotic susceptibility testing of the isolates were carried out following the standard protocol.</p><p><strong>Results: </strong>Culture positivity in this study was 19.2%. No significant difference was seen in culture positivity between male and female participants (<i>p</i> = 0.97). Gram-negative enteric bacteria were predominantly isolated (67.6%), including <i>Escherichia coli</i> (29.4%) and <i>Klebsiella aerogenes</i> (20.6%). <i>Staphylococcus aureus</i> was the most common Gram-positive bacterium isolated (23.5%). Three (37.5%) <i>S. aureus</i> isolates were methicillin-resistant. All isolates were sensitive to meropenem, and 97.1% were sensitive to imipenem; other sensitivity patterns were: ceftazidime (85.3%), ciprofloxacin (79.4%), ofloxacin (79.4%), and gentamicin (76.5%). There was low sensitivity to ampicillin (32.4%) and cotrimoxazole (38.2%). All Gram-positive isolates, including methicillin-resistant <i>S. aureus</i>, were sensitive to vancomycin.</p><p><strong>Conclusion: </strong>Regular surveillance of isolate sensitivity patterns, formulation of hospital antibiotic policies based on existing data and compliance with treatment guidelines will promote rational antibiotic use and reduce resistance among bacteria.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1807"},"PeriodicalIF":1.1,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9453184/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33459935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishment of haemoglobin A₂ reference intervals in Pretoria, South Africa: A retrospective secondary data analysis.","authors":"Cailin Nieuwenhuizen,&nbsp;Tshiphiri Netshidzivhani,&nbsp;Johan Potgieter","doi":"10.4102/ajlm.v11i1.1841","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1841","url":null,"abstract":"<p><strong>Background: </strong>Haemoglobinopathies are one of the most common inherited diseases worldwide. Quantification of haemoglobin A₂ is necessary for the diagnosis of the beta thalassaemia trait. In this context, it is important to have a reliable reference interval for haemoglobin A₂ and a local reference range for South Africa has not been established.</p><p><strong>Objective: </strong>This study aimed to establish reference intervals for haemoglobin A₂ using stored patient laboratory data.</p><p><strong>Methods: </strong>This descriptive study used retrospective data to evaluate haemoglobin A₂ levels determined using high-performance liquid chromatography at the National Health Laboratory Service haematology laboratory in Pretoria, South Africa. All tests performed from 01 October 2012 to 31 December 2020 were screened for inclusion; of these, 144 patients' data met the selection criteria. The reference interval was calculated using descriptive statistics (mean and standard deviation) with a 95% confidence interval.</p><p><strong>Results: </strong>Analysed data from enrolled patients showed a normal distribution. The mean age of the patients was 40 years (range: 3-84 years). The reference interval for haemoglobin A₂ calculated from this data was 2.3% - 3.6%. The minimum haemoglobin A₂ was 2.3% and the maximum was 3.9% with a mean of 2.95% and a standard deviation of 0.357%.</p><p><strong>Conclusion: </strong>A normal reference interval has been established for the population served by the laboratory that will assist with accurate diagnosis of the beta thalassaemia trait. This reference interval may also be useful to other laboratories that employ the same technology, especially smaller laboratories where obtaining a sufficiently large number of normal controls may be challenging.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1841"},"PeriodicalIF":1.1,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9453124/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33459934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of diversely isolated lytic phages against multi-drug resistant <i>Enterobacter cloacae</i> isolates in Kenya.","authors":"Ivy J Mutai,&nbsp;Angela A Juma,&nbsp;Martin I Inyimili,&nbsp;Atunga Nyachieo,&nbsp;Anthony K Nyamache","doi":"10.4102/ajlm.v11i1.1673","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1673","url":null,"abstract":"<p><strong>Background: </strong><i>Enterobacter cloacae</i> causes nosocomial infections in 15% of patients in low- and middle-income countries with emergence of carbapenem resistance. The utilisation of bacteriophages for therapeutic purposes is crucial for eradicating these resistant bacterial strains.</p><p><strong>Objective: </strong>This study evaluated the efficacy of lytic phages on bacterial isolates of <i>E. cloacae</i> and determined their stability in various physicochemical conditions.</p><p><strong>Methods: </strong>Twenty-nine lytic phages were isolated from the waste water of six informal settlements in Nairobi County, Kenya, from July 2019 to December 2020 and cross-reacted with 30 anonymised clinical isolates of <i>E. cloacae.</i> Six phages were then selected for physicochemical property studies. Phages were described as potent upon lysing any bacterial strain in the panel.</p><p><strong>Results: </strong>Selected phages were stable at 4 °C - 50 °C with a 5.1% decrease in titre in four of six phages and a 1.8% increase in titre in two of six phages at 50 °C. The phages were efficient following two weeks incubation at 4 °C with optimal activity at human body temperature (37 °C) and an optimal pH of 7.5. Phages were active at 0.002 M and 0.015 M concentrations of Ca²⁺ ions. The efficiency of all phages decreased with increased exposure to ultraviolet light. All phages (<i>n</i> = 29) showed cross-reactivity against anonymised clinical isolates of <i>E. cloacae</i> strains (<i>n</i> = 30). The most potent phage lysed 67.0% of bacterial strains; the least potent phage lysed 27.0%.</p><p><strong>Conclusion: </strong>This study reveals the existence of therapeutic phages in Kenya that are potent enough for treatment of multi-drug resistant <i>E. cloacae.</i></p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1673"},"PeriodicalIF":1.1,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9453119/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33459938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of hepatitis B virus core antibodies among blood donors in Nigeria: Implications for blood safety.","authors":"Foluke A Fasola,&nbsp;Adeola A Fowotade,&nbsp;Adedayo O Faneye,&nbsp;Adeyeni Adeleke","doi":"10.4102/ajlm.v11i1.1434","DOIUrl":"https://doi.org/10.4102/ajlm.v11i1.1434","url":null,"abstract":"<p><strong>Background: </strong>Anti-hepatitis B core antibody (anti-HBc) testing improves transfusion safety by detecting past and current hepatitis B virus (HBV) infection while detecting hepatitis B surface antigen (HBsAg) in serology-negative HBV infection. However, occult HBV infection (OBI) (serum or liver HBV DNA-positive but HBsAg-negative) remains unaddressed among replacement blood donors - family members or friends who donate to replace blood transfused to a relative.</p><p><strong>Objective: </strong>This study assessed risk factors for a positive anti-HBc test among donors with OBI and determined the anti-HBc-positive status of replacement donors.</p><p><strong>Methods: </strong>The study was conducted at the University College Hospital Blood Bank, Ibadan, Nigeria, using blood samples collected from blood donors between April 2019 and May 2019. Donors were screened for HBsAg by rapid diagnostic test (RDT) and enzyme-linked immunosorbent assay (ELISA) and anti-HBc by ELISA, while HBV DNA was detected using a semi-nested polymerase chain reaction.</p><p><strong>Results: </strong>Of the 274 participants, 15 (5.5%) were HBsAg-positive by RDT and 36 (13.1%) by ELISA, while 133 (48.5%) were anti-HBc positive. Out of 232 HBsAg-negative donors, 107 (46.1%) were anti-HBc positive. Of the 107 HBsAg-negative but anti-HBc-positive samples, only one (0.93%) was HBV DNA-positive. The HBV DNA-positive donor was HBsAg-negative by both RDT and ELISA tests.</p><p><strong>Conclusion: </strong>This study establishes a potential risk for HBV transmission from isolated anti-HBc-positive donors to blood recipients. HBc immunoglobulin (antibody) M testing to identify blood units requiring further screening with polymerase chain reaction to detect OBI can prevent HBV transmission through blood transfusion.</p>","PeriodicalId":45412,"journal":{"name":"African Journal of Laboratory Medicine","volume":" ","pages":"1434"},"PeriodicalIF":1.1,"publicationDate":"2022-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9350478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40701405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}