African Journal of Laboratory Medicine最新文献

Background: Hepatitis B virus is a public health burden in Uganda, yet little is known about its epidemiology in pregnancy.

Objective: This study aimed at determining the prevalence and associated risk factors of hepatitis B virus infection among pregnant women attending antenatal care at the Kyazanga Health Centre IV in Lwengo District, Uganda.

Methods: This cross-sectional study was conducted from April 2021 to June 2021 and analysed qualitative data that were collected using a structured in-person questionnaire. Aseptically collected blood specimens were screened for hepatitis B virus infection using an immunochromatographic rapid diagnostic test kit. Participants who were positive for the hepatitis B surface antigen (HBsAg) were further screened for hepatitis B envelope antigen (HBeAg) using commercial rapid diagnostic test kits.

Results: Out of 384 pregnant women studied, eight tested positive for HBsAg. This gave a prevalence of 2.1% (95% confidence interval: 1.0% - 4.1%); 5/8 (62.5%) were positive for HBeAg. None of the variables studied were significantly associated with HBsAg positivity among pregnant women.

Conclusion: Hepatitis B viral infection is still a public health challenge in pregnant women with possible risk for vertical transmission to their babies in the study area. We recommend routine screening for hepatitis B virus in pregnancy in addition to strengthening current strategies aimed at controlling and preventing hepatitis B infection spread and transmission.

Background: The recommendation for coagulation blood samples is to centrifuge at 4000 revolutions per minute (rpm) for 15 min to produce platelet-poor plasma before analysis. Rapid centrifugation, defined as centrifuging samples at higher speeds for shorter durations, could potentially reduce turn-around times (TAT), provided sample integrity is maintained.

Objective: This study assessed the impact of rapid centrifugation on routine coagulation assay results.

Methods: Blood samples were collected from volunteers at Inkosi Albert Luthuli Central Hospital and King Edward VIII Hospital, Durban, KwaZulu-Natal, South Africa, from September to November 2021. Samples were centrifuged using Method A, the current standard (4000 rpm/15 min), Method B (4000 rpm/10 min), Method C (5000 rpm/10 min) and Method D (5000 rpm/5 min). Platelet count, prothrombin time, activated partial thromboplastin time, thrombin time (TT), fibrinogen and D-dimer levels were analysed and results from Methods B, C and D compared to reference Method A.

Results: Platelet-poor plasma was obtained from all samples (n = 60) using Methods A and B, and from 33/60 (55%) samples using Methods C and D. Differences between Method A and Methods C and D for normal prothrombin time, normal D-dimer and abnormal TT results were statistically significant. Prothrombin time results correlated strongly across all methods, while TT and D-dimer results correlated poorly. Activated partial thromboplastin time and fibrinogen results showed no significant differences across all methods.

Conclusion: Rapid centrifugation at 4000 rpm/10 min (Method B) showed results consistent with the reference method. This method could potentially reduce the overall TAT for routine coagulation assays.

Background: Causes of death during the coronavirus disease 2019 (COVID-19) pandemic ranhttp://crossmark.crossref.org/dialog/?doi=10.4102/ajlm.v11i1.1766=pdf&date_stamp=2022-11-23ge from direct consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection to deaths unrelated to SARS-CoV-2. Another feature of the pandemic is the post-mortem testing for SARS-CoV-2. Understanding these aspects of COVID-19 are essential in planning and limiting the impact of SARS-CoV-2 virus on healthcare systems.

Objective: This study investigated the underlying causes of death and the presence of SARS-CoV-2 in bodies received at the 37 Military Hospital, Accra, Ghana, during the COVID-19 pandemic.

Methods: The study was conducted from 4-27 May 2020. Deceased patients that met the inclusion criteria were prospectively selected during the expanded surveillance period for SARS-CoV-2 testing, autopsy and determination of underlying and immediate cause of death.

Results: A total of 161 deceased patients were analysed with 53 autopsies. The overall positive test rate for SARS-CoV-2 was 14.9% (24/161 patients), with a positive rate of 5.0% (8/161 patients) for nasopharyngeal samples and 30.2% (16/161 patients) for bronchopulmonary samples. The underlying causes of death were not related to SARS-CoV-2 infection in 85.1% (137/161) of patients, SARS-CoV-2-associated 12.4% (20/161) and SARS-CoV-2-induced in 2.5% (4/161). Cardiovascular complications formed the most common cause of death in patients with or without SARS-CoV-2.

Conclusion: There was a high positive rate of SARS-CoV-2 in post-mortem cases. However, most deaths were not caused by SARS-CoV-2 but by cardiovascular complications. The high rate of bronchopulmonary positive results for SARS-CoV-2 requires that autopsies be done in suspicious cases with negative nasopharyngeal sampling.

Background: Human papilloma virus (HPV) is associated with a subset of oropharyngeal squamous cell carcinoma and mouth or throat warts. However, there is currently limited information about oral HPV infections in Nigeria.

Objective: This study aimed to provide information on the occurrence and circulating genotypes of HPV among patients attending three (one government and two private) dental clinics in Ibadan, Nigeria.

Methods: An oral swab was collected from 231 dental clinic attendees in Ibadan between January 2016 and March 2017 and tested for HPV DNA by polymerase chain reaction targeting the E6/7 genes of the virus.

Results: Twenty-three of the 231 swab samples were HPV DNA positive comprising 16 mono-infections and seven co-infections in 13 males and ten females. Genotype 16 was present in ten patients, genotype 6/11 in five, Genotype 18 and genotype 33 in four each, genotype 31 in three and genotype 39 in one. Twenty-one cases were high-risk HPV genotypes, while two were low-risk. Samples had co-infection and five had low risk type 6/11 either as single or as co-infection. Persons who had engaged in oral sex as well as those aged 21-30 years has significantly higher prevalence.

Conclusion: This study showed that although HPV genotype 16 is the most common type among dental clinic attendees in Ibadan, other genotypes are also circulating and that oral sex is a risk factor for the infection. Therefore, introducing a multivalent HPV vaccine will reduce the risk of HPV-associated oropharyngeal carcinoma and other cancers in Nigeria.

Laboratory systems have been largely neglected on the margins of health systems in Africa. However, since the 2000s, many African countries have benefited from massive investments to strengthen laboratory capacities through projects fighting priority diseases (HIV/AIDS, tuberculosis, malaria). This review examined the laboratory capacities of the Economic Community of Central African States (ECCAS). Online research using specific terms was carried out. Studies published between 2000 and 2021 on the role of the laboratory in disease and antimicrobial resistance surveillance in the 11 ECCAS countries were considered. The number of human and animal health laboratories meeting international standards was very low in the sub-region. There were only seven International Organization for Standardization (ISO) 15189-accredited human health laboratories, with five in Cameroon and two in Rwanda. There were five high biosafety level (BSL) laboratories (one BSL3 laboratory each in Cameroon, the Central African Republic, Democratic Republic of Congo and the Republic of Congo, and one BSL4 laboratory in Gabon) and three ISO 17025-accredited laboratories in the ECCAS sub-region. Only six countries currently have whole-genome sequencing devices, which is insufficient for a sub-region as large and populous as ECCAS. Yet, a plethora of pathogens, particularly haemorrhagic viruses, are endemic in these countries. The need for laboratory capacity strengthening following a One Health approach is imperative. Since emerging and re-emerging zoonotic infectious diseases are projected to triple in frequency over the next 50 years and given the inextricable link between human and animal health, actors in the two health sectors must collaborate to preserve world health.

Background: Commercial multicolour fixed immunophenotyping panels can improve flow cytometric diagnostic immunophenotyping repertoire.

Objective: This study validated the commercially available, standardised Beckman Coulter lyophilised DURAClone RE panels to discriminate specific haematolymphoid subtypes.

Methods: We compared the diagnostic capability of the DURAClone acute leukaemia B (ALB), chronic leukaemia B (CLB), and plasma cells (PC) panels to the predicate second-line panels in Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa, from April to August 2020. Clinical diagnostic concordance between the in-house second-line immunophenotyping (the predicate method) and DURAClone was established. The ALB panels tested for precursor B-cell acute lymphoblastic leukaemia (n = 11) or normal bone marrow haematogones (n = 9); CLB panels established haematolymphoid subtypes of mature B-cell lymphoproliferative disorders (B-LPD) (n = 20), while PC panels detected plasma cell dyscrasias (PCD) (n = 17). Flow cytometer setup and data interpretation to discriminate normal and aberrant immunophenotypes were per manufacturer's instructions.

Results: There was 100% clinical diagnostic concordance between the predicate and the test panels for second-line diagnostic investigation of B-ALL (with additional CD56), mature B-LPD (with additional discernment of CD81, ROR-1, CD79b and CD43) and PCD.

Conclusion: The DURAClone CLB exceeded the predicate second-line performance, offering extended second-line diagnostic discernment of mature B-LPD subtypes and discernment of CD5+ B-LPD from other non-CD5+ (or CD5-) B-LPD; likewise, the PC panels enabled discovery of PCD. While ALB testing offered no additional diagnostic advantage over existing predicate investigation, CD58 did offer additional information to discern haematogones from B-ALL.

Background: Optimal protocols for efficient and reproducible protein extraction from formalin-fixed paraffin-embedded (FFPE) tissues are not yet standardised and new techniques are continually developed and improved. The effect of polyethylene glycol (PEG) 20 000 on protein extraction efficiency has not been evaluated using human FFPE colorectal cancer tissues and there is no consensus on the protein extraction solution required for efficient, reproducible extraction.

Objective: The impact of PEG 20 000 on protein extraction efficiency, reproducibility and protein selection bias was evaluated using FFPE colonic tissue via liquid chromatography tandem mass spectrometry analysis.

Methods: This study was conducted from August 2017 to July 2019 using human FFPE colorectal carcinoma tissues from the Anatomical Pathology department at Tygerberg Hospital in South Africa. Samples were analysed via label-free liquid chromatography tandem mass spectrometry to determine the impact of using PEG 20 000 in the protein extraction solution. Data were assessed regarding peptide and protein identifications, method efficiency, reproducibility, protein characteristics and organisation relating to gene ontology categories.

Results: Polyethylene glycol 20 000 exclusion increased peptides and proteins identifications and the method was more reproducible compared to the samples processed with PEG 20 000. However, no differences were observed with regard to protein selection bias. We found that higher protein concentrations (> 10 µg) compromised the function of PEG.

Conclusion: This study indicates that protocols generating high protein yields from human FFPE tissues would benefit from the exclusion of PEG 20 000 in the protein extraction solution.