African Journal of Laboratory Medicine最新文献

Background: Iron deficiency is a common disorder, especially in developing countries. Accurately assessing iron status remains challenging, particularly for patients with chronic diseases such as HIV and chronic kidney disease, prevalent in South Africa.

Objective: This study aimed to determine how ferritin cut-offs affect iron status classification in adult patients treated at a tertiary hospital in South Africa. Additionally, it assessed the frequency of these conditions and the impact of age and gender on iron status.

Methods: This retrospective study analysed iron profiles in adult patients from 01 October 2020 to 31 March 2021. Iron status was categorised into five groups: iron deficiency anaemia (IDA), anaemia of chronic disease, IDA with anaemia of chronic disease, iron deficiency without anaemia, and iron replete based on haemoglobin, transferrin saturation, and ferritin levels. The impact of using two different ferritin cut-off values (15 µg/L and 30 µg/L) was investigated.

Results: The study included 3221 complete iron profiles. There was a predominance of female patients (2.2:1 ratio). Anaemia of chronic disease was the most prevalent iron disorder (39%), regardless of ferritin cut-off. Using a higher ferritin cut-off of 30 µg/L significantly increased the detection rates of both IDA and iron deficiency without anaemia (p < 0.001).

Conclusion: This study suggests that a higher ferritin threshold (30 µg/L) might improve diagnosis of iron disorders in settings with high inflammatory diseases. Further studies are needed to refine thresholds. Local guidelines should be adjusted to consider higher ferritin cut-offs, and longitudinal studies are recommended to evaluate long-term outcomes.

What this study adds: This study confirms the use of higher ferritin cut-offs for enhanced detection of iron deficiency states. The findings also emphasise the ongoing need for establishing simple, standardised, and accurate methods for iron status classification.

Background: Critical laboratory results are test results suggesting a patient is in immediate danger unless treatment is administered promptly. There is a paucity of studies in sub-Saharan Africa on clinicians' utility of these results and affected patients' outcomes. In our resource-limited setting in South Africa, we rely on telephonic communication to convey critical results.

Objective: The aim of this study was to determine the average time for clinicians to acknowledge these results on the laboratory information system and to determine the outcome of affected patients.

Methods: A retrospective descriptive audit at Tygerberg Academic Hospital was conducted between 01 October 2021 and 31 March 2022. Critical results and the time of acknowledgement by clinicians on the laboratory information system were obtained from inpatients and outpatients. One hundred and twenty inpatient critical results were randomly selected for a folder review to determine patient outcome.

Results: Overall, 2514 critical results were reported, and 63 results were excluded. The remaining 2451 results were obtained from 1346 patients. The majority (94.5%) of results were obtained from inpatients, where 1681 (68.6%) were acknowledged within 24 h. The folder audit of 120 patients determined that 40 (33.3%) patients demised. In 82 (68.3%) patients, communication of a critical result did not alter clinical management.

Conclusion: Critical laboratory results are crucial to patient care. This study found that approximately one-third of critical laboratory results were not used within 24 h. Engaging clinicians in current practice and implementing a means of improved communication of critical results is required.

What this study adds: The study adds to the evidence of challenges experienced with communicating critical results to clinicians which could impact patient care. This is especially true in resource-limited settings; clinicians need to be made aware of the importance of these results, and communication modes need to be improved.

Background: Despite the significant burden of menorrhagia (bleeding > 80 mL every menstrual cycle) among women in Western Kenya, it remains unknown whether coagulation disorders are an important underlying cause of this condition in the region.

Objective: This study assessed differences in coagulation profiles, associations between menorrhagia and coagulation profiles and compared morphological features of platelets among women attending Bungoma County Referral Hospital in Kenya.

Methods: A comparative cross-sectional study of women with and without menorrhagia, aged 18-45 years, was performed between December 2022 and September 2023. Sociodemographic factors, prothrombin time (PT), activated partial thromboplastin time, thrombin time, fibrinogen, international normalised ratio (INR), and platelet count were compared between groups, and associations with menorrhagia were assessed. Prothrombin time and INR levels above normal references were deemed increased.

Results: A total of 428 (214 per group) women were included. Family history of bleeding disorders (p < 0.0001) was more frequent in menorrhagic than in non-menorrhagic women. Additionally, menorrhagic women had high PT (p < 0.0001) and high INR (p < 0.0001) levels. Menorrhagia was significantly associated with an increased PT (odds ratio = 2.129, 95% confidence interval = 1.658-2.734; p < 0.0001) and increased INR (odds ratio = 7.479, 95% confidence interval = 3.094-18.080; p < 0.0001).

Conclusion: In this population in Western Kenya, menorrhagia was associated with a family history of bleeding disorders, increased PT, and increased INR. Routine assessment of the coagulation profile and family history of bleeding disorders is crucial for diagnosing and managing menorrhagia.

What this study adds: Our findings suggest that menorrhagic and non-menorrhagic women differ in terms of PT and INR, which may be predictive of menorrhagia.

Background: HIV testing remains an entry point into HIV care and treatment services. In 2007, Nigeria adopted and implemented a two-test rapid HIV testing algorithm of three HIV rapid test kits, following the sequence: Alere Determine (first test), Unigold^TM (second test), and STAT-PAK^® as the tie-breaker. Sub-analysis of the 2018 Nigeria HIV/AIDS Indicator and Impact Survey data showed significant discordance between the first and second tests, necessitating an evaluation of the algorithm. This manuscript highlights lessons learnt from that evaluation.

Intervention: A two-phased evaluation method was employed, including abstraction and analysis of retrospective HIV testing data from January 2017 to December 2019 from 24 selected sites supported by the United States President's Emergency Plan for AIDS Relief programme. A prospective evaluation of HIV testing was done among 2895 consecutively enrolled and consented adults, aged 15-64 years, accessing HIV testing services from three selected sites per state across the six geopolitical zones of Nigeria between July 2020 and September 2020. The prospective evaluation was performed both in the field and at the National Reference Laboratory under controlled laboratory conditions. Stakeholder engagements, strategic selection and training of study personnel, and integrated supportive supervision were employed to assure the quality of evaluation procedures and outcomes.

Lessons learnt: The algorithm showed higher sensitivity and specificity in the National Reference Laboratory compared with the field. The approaches to quality assurance were integral to the high-quality study outcomes.

Recommendations: We recommend comparison of testing algorithms under evaluation against a gold standard.

What this study adds: This study provides context-specific considerations in using World Health Organization recommendations to evaluate the Nigerian national HIV rapid testing algorithm.

Background: The clinical presentations of coronavirus disease 2019 (COVID-19) exhibit significant variation, ranging from asymptomatic cases to mortality resulting from severe pneumonia. Host genetics can partially explain this variation.

Objective: This study evaluated possible associations between severity and outcome of COVID-19 and single nucleotide polymorphism (SNP) rs2285666 in the ACE2 gene and SNP rs2070788 in the TMPRSS2 gene.

Methods: The study included a sample of 100 consecutive adult patients admitted to the COVID-19 Isolation and Intensive Care Units of the Zagazig University Hospitals, Zagazig, Egypt from July 2021 to November 2021. For rs2285666, polymerase chain reaction-restriction fragment length polymorphism was carried out. For rs2070788, real-time polymerase chain reaction was performed.

Results: For rs2285666, the GA genotype was the most frequent among female patients (39% [16/41]) and the A genotype was more prevalent among male patients (54.2% [32/59]). For rs2070788, the AA genotype was the most frequent among all patients (46% [46/100]). No rs2285666 or rs2070788 genotypes or allele frequencies had significant associations with either severity or outcomes of patients.

Conclusion: This study found no significant associations of COVID-19 severity or outcomes of patients with genotypes or allele frequencies of the rs2285666 SNP in the ACE2 gene or the rs2070788 SNP of the TMPRSS2 gene. The search for other genetic associations with COVID-19 infection is still required.

What this study adds: The study reveals that host genetics explain the variation observed in the disease. Specific genetic variants can confer either increased susceptibility or resistance to the disease.

Background: The impact of antimicrobial resistance on children living in resource-limited countries has been underreported, despite its established global threat.

Objective: This retrospective study aimed to describe the trend of antibiotic susceptibility in the paediatric age group.

Methods: Sensitivity test report data consisting of 300 paediatric patients aged 18 hours to 192 months were retrieved from the microbiology laboratory records at a state-owned children's hospital in Nigeria over a period of 4 months starting from December 2021 to March 2022. Five genera (Escherichia coli, Klebsiella spp., Pseudomonas spp., Staphylococcus aureus and Streptococcus spp.) were cultured as recommended by the Clinical Laboratory Standard Institute, using the Kirby Bauer disc diffusion method. Antimicrobial susceptibility testing was carried out on isolates using 15 different antibiotics.

Results: Staphylococcus aureus was the most frequent pathogen isolated 32.1% (50/156) and Pseudomonas spp. was the least frequent pathogen isolated 7.1% (11/156) in all samples. The isolates with the highest rate of resistance to the tested antibiotics were S. aureus 32.1% (50/156), E. coli 28.2% (44/156) and Klebsiella spp. 20.5% (32/156). Isolates in all age groups were more resistant to ampicillin, amoxicillin + clavulanic acid, cefuroxime and cefepime.

Conclusion: Antibiotic resistance is high, especially the younger Nigerian children. Strict antibiotic protocols should be adhered to especially in the use of empirical antibiotic therapy in hospitals.

What this study adds: Our study reveals a higher trend of antibiotic resistance, especially in younger children. It further shows that the pathogens are most resistant to the most available empirical antibiotics in Nigeria.

Background: Respiratory infections are a major contributor to hospital admissions. Identification of respiratory pathogens by means of conventional culture and serology methods remains challenging. Multiplex molecular assays are an appealing alternative that endeavours to be rapid, more accurate and less arduous.

Objective: The study aimed to compare the clinical performance of three commercial multiplex molecular assays for respiratory viruses.

Methods: Forty-eight respiratory specimens obtained from patients at Tygerberg Hospital in the Western Cape province of South Africa were studied. These specimens were collected between May 2020 and August 2020. The results of the Seegene Anyplex™ II RV16, FilmArray^® Respiratory 2.1 plus Panel (FARP), and QIAstat-Dx^® Respiratory SARS-CoV-2 Panel (QRP) were analysed based on the overlapping targets. A composite reference standard was applied to provide a standard reference for comparison.

Results: The overall sensitivity of the Seegene Anyplex™ II RV16 was 96.6% (57/59), the FARP 98.2% (56/57) and the QRP 80.7% (46/57). The overall specificities were 99.8% (660/661), 99.0% (704/711) and 99.7% (709/711), respectively. The QRP failed to detect coronaviruses and parainfluenza viruses in 41.7% (5/12) and 28.6% (4/14) of positive specimens, respectively, while the FARP produced the lowest target specificity of 88.4% (38/43) for rhinovirus/enterovirus.

Conclusion: The overall specificity of all three platforms was comparable; however, the sensitivity of the QRP was inferior to that of the ARV and FARP.

What this study adds: This study adds to the body of performance characteristics described for respiratory multiplex panels, especially in the African context where molecular diagnostics for infectious diseases are gaining momentum.