African Journal of Laboratory Medicine - latest Issue
Volume 5, Issue 1, 2016
Performance of the Cellslide® automated liquid-based cytology system amongst HIV-positive women : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.278More Less
Background: Many women undergoing cervical screening as part of a national South African screening programme may be positive for HIV. The performance of liquid-based cytology (LBC) on samples from HIV-positive women needs to be determined.
Objectives: The performance of the Cellslide® automated LBC system was evaluated as a possible alternative to conventional cytology in a national cervical cancer screening programme.
Methods: Split samples from 348 HIV-positive women attending an HIV treatment clinic in Johannesburg, South Africa were examined by conventional cytology and monolayer LBC methods. All samples were stained, examined and reported in the same manner. Cytotechnologists were blinded to the conventional smear diagnosis if the LBC smear was screened and vice versa.
Results: The same percentage of inadequate smears (1.4%) was obtained by conventional cytology and LBC. Atypical squamous cells of undetermined significance were observed in 5.2% of conventional smears and 4.0% of LBC smears. Low-grade squamous intraepithelial lesions were found in 35.6% of conventional smears and 32.7% of LBC smears. Only one conventional smear was categorised as atypical squamous cells - cannot exclude a high-grade lesion, whereas five such cases were identified on LBC. High-grade squamous intraepithelial lesions were seen in 21.6% of conventional smears and 23.3% LBC smears. No invasive carcinoma was identified.
Conclusion: The performance of the Cellslide® LBC system was similar to that of conventional cytology in this population of high-risk HIV-positive women, indicating that it may be introduced successfully as part of a cervical cancer screening programme.
Increased utilisation of PEPFAR-supported laboratory services by non-HIV patients in Tanzania : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –7 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.318More Less
Background: It is unknown to what extent the non-HIV population utilises laboratories supported by the President's Emergency Plan for AIDS Relief (PEPFAR).
Objectives: We aimed to describe the number and proportion of laboratory tests performed in 2009 and 2011 for patients referred from HIV and non-HIV services (NHSs) in a convenience sample collected from 127 laboratories supported by PEPFAR in Tanzania. We then compared changes in the proportions of tests performed for patients referred from NHSs in 2009 vs 2011.
Methods: Haematology, chemistry, tuberculosis and syphilis test data were collected from available laboratory registers. Referral sources, including HIV services, NHSs, or lack of a documented referral source, were recorded. A generalised linear mixed model reported the odds that a test was from a NHS.
Results: A total of 94 132 tests from 94 laboratories in 2009 and 157 343 tests from 101laboratories in 2011 were recorded. Half of all tests lacked a documented referral source. Tests from NHSs constituted 42% (66 084) of all tests in 2011, compared with 31% (29 181) in 2009. A test in 2011 was twice as likely to have been referred from a NHS as in 2009 (adjusted odds ratio: 2.0 [95% confidence interval: 2.0-2.1]).
Conclusion: Between 2009 and 2011, the number and proportion of tests from NHSs increased across all types of test. This finding may reflect increased documentation of NHS referrals or that the laboratory scale-up originally intended to service the HIV-positive population in Tanzania may be associated with a 'spillover effect' amongst the general population.
Dried blood spot specimen quality and validation of a new pre-analytical processing method for qualitative HIV-1 PCR, KwaZulu-Natal, South Africa : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.349More Less
Background: Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume.
Objectives: This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method.
Methods: Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed.
Results: Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems.Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997.
Conclusions: The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care.
Real-time polymerase chain reaction optimised for hepatitis C virus detection in dried blood spots from HIV-exposed infants, KwaZulu-Natal, South Africa : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.269More Less
Background: There is a paucity of data on the prevalence of hepatitis C virus (HCV) in children,particularly in sub-Saharan Africa. A major obstacle in resource-limited settings for polymerase chain reaction (PCR) testing is the necessity for specimen transportation and storage at low temperatures. There are numerous recent studies of using real-time HCV PCR for diagnosis and screening of plasma and serum, but few have looked at using dried blood spot (DBS) specimens.
Objectives: The aim of this study was to optimise a real-time HCV PCR method to detect HCV RNA from infant DBS specimens for use as a tool for HCV surveillance in KwaZulu-Natal, South Africa.
Method: The LightCycler® 2.0 instrument was used for the HCV PCR using the LightCycler&3174; RNA Master SYBR Green I kit. Template volume, primer concentration and primer annealing temperatures were optimised and the method was used on 179 DBS specimens from HIV-exposed infants in KwaZulu-Natal.
Results: Primer concentrations adjusted to 0.25 µM and a template volume of 10 µL improved the PCR amplification. Primer annealing temperatures lowered from 65 °C to 58 °C resulted in higher quantities of amplified PCR product. The limit of detection of the optimised HCV PCR assay was between 1200 IU/mL and 3580 IU/mL of HCV RNA. HCV was not detected in any of the 179 DBS specimens.
Conclusion: The optimised real-time HCV PCR on infant DBS specimens performed well, but HCV was not found in this surveillance study. HIV infection may have little impact on the vertical transmission of HCV in this region.
Implications of the introduction of laboratory demand management at primary care clinics in South Africa on laboratory expenditure : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.339More Less
Background: Diagnostic health laboratory services are regarded as an integral part of the national health infrastructure across all countries. Clinical laboratory tests contribute substantially to health system goals of increasing quality of care and improving patient outcomes.
Objectives: This study aimed to analyse current laboratory expenditures at the primary healthcare (PHC) level in South Africa as processed by the National Health Laboratory Service and to determine the potential cost savings of introducing laboratory demand management.
Methods: A retrospective cross-sectional analysis of laboratory expenditures for the 2013/2014financial year across 11 pilot National Health Insurance health districts was conducted. Laboratory expenditure tariff codes were cross-tabulated to the PHC essential laboratory tests list (ELL) to determine inappropriate testing. Data were analysed using a Microsoft Access database and Excel software.
Results: Approximately R35 million South African Rand (10%) of the estimated R339 million in expenditures was for tests that were not listed within the ELL. Approximately 47% of expenditure was for laboratory tests that were indicated in the algorithmic management of patients on antiretroviral treatment. The other main cost drivers for non-ELL testing included full blood count and urea, as well as electrolyte profiles usually requested to support management of patients on antiretroviral treatment.
Conclusions: Considerable annual savings of up to 10% in laboratory expenditure are possible at the PHC level by implementing laboratory demand management. In addition,to achieve these savings, a standardised PHC laboratory request form and some form of electronic gate keeping system that must be supported by an educational component should be implemented.
Evaluation of the accuracy of the CellaVision? DM96 in a high HIV-prevalence population in South Africa : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –5 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.313More Less
Introduction: The CellaVision? DM96 (DM96) is a digital microscopy system which performs well in developed countries. However, to date it has not been evaluated in Africa, where the pathology spectrum encountered is very different. In particular, its utility in a setting with high HIV prevalence has not been assessed, which is of interest because of the morphological aberrations often seen in HIV-positive patients.
Objectives: This study aimed to evaluate the accuracy of the DM96 in a South African laboratory, with emphasis on its performance in samples collected from HIV-positive patients.
Methods: A total of 149 samples submitted for a routine differential white cell count in 2012 and 2013 at the Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa were included, of which 79 (53.0%) were collected from HIV-positive patients. Results of DM96 analysis pre- and post-classification were compared with a manual differential white cell count and the impact of HIV infection and other variables of interest were assessed.
Results: Pre- and post-classification accuracies were similar to those reported in developed countries. Reclassification was required in 16% of cells, with particularly high mis-classification rates for eosinophils (31.7%), blasts (33.7%) and basophils (93.5%). Multivariate analysis revealed a significant relationship between the number of misclassified cells and both the white cell count ( p = 0.035) and the presence of malignant cells in the blood ( p = 0.049), but not with any other variables analysed, including HIV status.
Conclusion: The DM96 exhibited acceptable accuracy in this South African laboratory, which was not impacted by HIV infection. However, as it does not eliminate the need for experienced morphologists, its cost may be unjustifiable in a resource-constrained setting.
The viable but non-culturable state in pathogenic Escherichia coli : a general review : review articleSource: African Journal of Laboratory Medicine 5, pp 1 –9 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.368More Less
Background: The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC) state, where they are 'alive' or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state.
Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state.
Method: A literature review was conducted to ascertain the possible impact of E. coli entering into the VBNC state.
Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation.
Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at any time, be resuscitated and become virulent again.
Implementation of the World Health Organization Regional Office for Africa Stepwise Laboratory Quality Improvement Process Towards Accreditation : lessons from the fieldSource: African Journal of Laboratory Medicine 5, pp 1 –8 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.280More Less
Background: The increase in disease burden has continued to weigh upon health systems in Africa. The role of the laboratory has become increasingly critical in the improvement of health for diagnosis, management and treatment of diseases. In response, the World Health Organization Regional Office for Africa (WHO AFRO) and its partners created the WHO AFRO Stepwise Laboratory (Quality) Improvement Process Towards Accreditation (SLIPTA) program.
SLIPTA implementation process: WHO AFRO defined a governance structure with roles and responsibilities for six main stakeholders. Laboratories were evaluated by auditors trained and certified by the African Society for Laboratory Medicine. Laboratory performance was measured using the WHO AFRO SLIPTA scoring checklist and recognition certificates rated with 1-5 stars were issued.
Preliminary results: By March 2015, 27 of the 47 (57%) WHO AFRO member states had appointed a SLIPTA focal point and 14 Ministers of Health had endorsed SLIPTA as the desired programme for continuous quality improvement. Ninety-eight auditors from 17 African countries, competent in the Portuguese (3), French (12) and English (83) languages, were trained and certified. The mean score for the 159 laboratories audited between May 2013 and March 2015 was 69% (median 70%; SD 11.5; interquartile range 62-77). Of these audited laboratories, 70% achieved 55% compliance or higher (2 or more stars) and 1% scored at least 95% (5 stars). The lowest scoring sections of the WHO AFRO SLIPTA checklist were sections 6 (Internal Audit) and 10 (Corrective Action), which both had mean scores below 50%.
Conclusion: The WHO AFRO SLIPTA is a process that countries with limited resources can adopt for effective implementation of quality management systems. Political commitment, ownership and investment in continuous quality improvement are integral components of the process.
Development of immunohistochemistry services for cancer care in western Kenya : implications for low- and middle-income countries : lessons from the fieldSource: African Journal of Laboratory Medicine 5, pp 1 –7 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.187More Less
Background: Cancer is becoming a major cause of mortality in low- and middle-income countries. Unlike infectious disease, malignancy and other chronic conditions require significant supportive infrastructure for diagnostics, staging and treatment. In addition to morphologic diagnosis, diagnostic pathways in oncology frequently require immunohistochemistry (IHC) for confirmation. We present the experience of a tertiary-care hospital serving rural western Kenya, which developed and validated an IHC laboratory in support of a growing cancer care service.
Objectives, methods and outcomes: Over the past decade, in an academic North-South collaboration, cancer services were developed for the catchment area of Moi Teaching and Referral Hospital in western Kenya. A major hurdle to treatment of cancer in a resource-limited setting has been the lack of adequate diagnostic services. Building upon the foundations of a histology laboratory, strategic investment and training were used to develop IHC services. Key elements of success in this endeavour included: translation of resource-rich practices to a resource-limited setting, such as using manual, small-batch IHC instead of disposable- and maintenance-intensive automated machinery, engagement of outside expertise to develop reagent-efficient protocols and supporting all levels of staff to meet the requirements of an external quality assurance programme.
Conclusion: Development of low- and middle-income country models of services, such as the IHC laboratory presented in this paper, is critical for the infrastructure in resource-limited settings to address the growing cancer burden. We provide a low-cost model that effectively develops these necessary services in a challenging laboratory environment.
Evaluating laboratory request forms submitted to haematology and blood transfusion departments at a hospital in Northwest Nigeria : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.381More Less
Background: The laboratory request form (LRF) is a communication link between laboratories, requesting physicians and users of laboratory services. Inadequate information or errors arising from the process of filling out LRFs can significantly impact the quality of laboratory results and, ultimately, patient outcomes.
Objective: We assessed routinely-submitted LRFs to determine the degree of correctness, completeness and consistency.
Methods: LRFs submitted to the Department of Haematology (DH) and Blood Transfusion Services (BTS) of Aminu Kano Teaching Hospital in Kano, Nigeria, between October 2014 and December 2014, were evaluated for completion of all items on the forms. Performance in four quality indicator domains, including patient identifiers, test request details, laboratory details and physician details, was derived as a composite percentage.
Results: Of the 2084 LRFs evaluated, 999 were from DH and 1085 from BTS. Overall, LRF completeness was 89.5% for DH and 81.2% for BTS. Information on patient name, patient location and laboratory number were 100% complete for DH, whereas only patient name was 100% complete for BTS. Incomplete information was mostly encountered on BTS forms for physician's signature (60.8%) and signature of laboratory receiver (63.5%). None of the DH and only 9.4% of BTS LRFs met all quality indicator indices.
Conclusion: The level of completion of LRFs from these two departments was suboptimal. This underscores the need to review and redesign the LRF, improve on training and communication between laboratory and clinical staff and review specimen rejection practices.
Source: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.288More Less
Background: Recent reports have shown an expansion of Lassa virus from the area where it was first isolated in Nigeria to other areas of West Africa. Two Ghanaian soldiers on a United Nations peacekeeping mission in Liberia were taken ill with viral haemorrhagic fever syndrome following the death of a sick colleague and were referred to a military hospital in Accra, Ghana, in May 2013. Blood samples from the soldiers and five asymptomatic close contacts were subjected to laboratory investigations.
Objective: We report the results of these investigations to highlight the importance of molecular diagnostic applications and the need for heightened awareness about Lassa fever in West Africa.
Methods: We used molecular assays on sera from the two patients to identify the causative organism. Upon detection of positive signals for Lassa virus ribonucleic material by two different polymerase chain reaction assays, sequencing and phylogenetic analyses were performed.
Results: The presence of Lassa virus in the soldiers' blood samples was shown by L-gene segment homology to be the Macenta and las803792 strains previously isolated in Liberia, with close relationships then confirmed by phylogenetic tree construction. The five asymptomatic close contacts were negative for Lassa virus.
Conclusions: The Lassa virus strains identified in the two Ghanaian soldiers had molecular epidemiological links to strains from Liberia. Lassa virus was probably responsible for the outbreak of viral haemorrhagic fever in the military camp. These data confirm Lassa fever endemicity in West Africa.
The prevalence of hepatitis B virus infection in HIV-positive and HIV-negative infants : KwaZulu-Natal, South Africa : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –5 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.283More Less
Background: The prevalence of hepatitis B virus (HBV) amongst South African infants and children has been reported in the pre-HIV era. Despite the reported high prevalence of HIV in the general population of South Africa, the rate of HIV/HBV co-infection amongst infants and children remains poorly reported.
Objectives: We describe the prevalence of HBV infection amongst HIV-positive and HIV-negative infants by molecular methods of diagnosis using dried blood spot samples.
Methods: This retrospective cross-sectional study was conducted between July 2011 and December 2011 in an academic referral laboratory offering viral diagnostic services to the entire KwaZulu-Natal province of South Africa. A total of 322 study samples were collected from discarded residual dried blood spot samples following routine infant diagnosis of HIV. Equal proportions of HIV-positive and HIV-negative infant specimens were studied. Statistical differences in the prevalence of HBV between the HIV-positive and HIV-negative samples were calculated using the Pearson chi-square test, and a p-value < 0.05 was considered statistically significant. Further testing for HBV DNA using a nested polymerase chain reaction method was performed.
Results: The overall prevalence of HBV was 10%. In the HIV-positive group, 21 of 161 infants tested positive for HBV compared with 12 of 161 HIV-negative infants who tested positive for HBV. The proportion of infants infected with HBV was marginally higher amongst HIV-positive infants (13.0%; 95% CI 6.8-19.9) compared with HIV-negative infants (7.5%; 95% CI 2.5-13.7; P = 0.098), though not statistically significant.
Conclusion: The finding of a 10% HBV prevalence in this infant cohort is clinically significant. The non-statistically significant difference in HBV prevalence between the HIV-positive and HIV-negative infants suggests that high prevalence of HBV infection in children may be a problem independent of HIV.
Whole blood pathogen reduction technology and blood safety in sub-Saharan Africa : a systematic review with regional discussion : review articleSource: African Journal of Laboratory Medicine 5, pp 1 –9 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.363More Less
Background : Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region.
Objective : This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region.
Method : The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinicians, scientists and professional bodies in the region, including the World Health Organization's Regional Office for Africa, to examine the suitability of PRT for improving the safety of whole blood transfusion, a prevalent transfusion format in the region.
Results : Existing literature suggests that combining PRT with current blood safety measures (such as serology) would improve the safety and adequacy of the blood supply for transfusions in sub-Saharan Africa. This was echoed by the findings of the stakeholder meetings.
Conclusion : Following a detailed appraisal of two leading PRT systems, the Mirasol® PRT System and the Cerus S-303 System, we suggest that companies conduct comprehensive toxicological evaluation of the agents used for PRT and publish this in the scientific literature. We also recommend that the safety and efficacy of these technologies should be established in a randomised clinical trial conducted in sub-Saharan Africa.
Experiential Bloom's Taxonomy learning framework for point-of-care diagnostics training of primary healthcare workers : opinion paperSource: African Journal of Laboratory Medicine 5, pp 1 –4 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.449More Less
The delivery of accessible, affordable and equitable primary healthcare (PHC) is a key focus in many resource-limited settings. One strategy that has been used to improve health access and healthcare equity in rural and resource-limited settings is the use of point-of-care (POC) diagnosticsin PHC clinics. POC testing is defined as: pathology testing performed in a clinical setting at the time of patient consultation, generating a result that is used to make an immediate informed clinical decision that contributes to an improved health outcome for the patient. Although itrelies on clinical, non-laboratory staff and frontline workers, such as nurses, to perform diagnostic testing, POC testing is seen as one of the ways to improve affordability, access and equity in rural areas. A primary advantage of POC diagnostics is that the completion of the test and treatment cycle in the same encounter is conducive to retention in care and patient outcomes.
Source: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.432More Less
Background and objectives: Knowledge of local and regional antimicrobial resistance (AMR) is important for clinical decision making. However, surveillance capacity for AMR is lacking throughout East Africa, and current AMR data are sparse. We sought to address this gap by summarising all available high-quality data on AMR in the East Africa region.
Method: We searched the PubMed database and African Journals Online archives in April and May 2015 using the search term 'antimicrobial resistance AND sub-Saharan Africa' to find articles published from 2005 onwards. Only full-text articles in English were included.
Results: We included 12 published articles in our analysis. Most articles were on bloodstream infections, hospital-based and cross-sectional in design; a majority described either community- or hospital-acquired infections. High levels of AMR to commonly-used antibiotics were reported, including 50% - 100% resistance to ampicillin and cotrimoxazole infections, emerging resistance to gentamicin (20% - 47%) and relatively high levels of resistance to ceftriaxone (46% - 69%) among Gram-negative infections. Much of the resistance was reported to be in Klebsiella species and Escherichia coli. Among Gram-positive infections, extensive resistance was reported to ampicillin (100%), gentamicin and ceftriaxone (50% - 100%), with methicillin-resistant Staphylococcus aureus prevalence ranging from2.6% - 4.0%.
Conclusion: Overall, bacterial resistance was reported among commonly-used antibiotics(ampicillin, gentamicin and ceftriaxone), raising concern that these antibiotics may no longer be useful for treating moderate or severe bacterial infections in East Africa. Thus, empirical treatment of bacterial infections needs to be reconsidered and guided by local assessment of AMR. Improvements in the limited amount of quality data and lack of harmonisation in assessing the burden of AMR are also needed.
Evaluation of the BioFire® FilmArray® Blood Culture Identification Panel on positive blood cultures in a regional hospital laboratory in KwaZulu-Natal : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –8 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.411More Less
Background: There are presently many non-culture-based methods commercially available to identify organisms and antimicrobial susceptibility from blood culture bottles. Each platform has its benefits and limitations. However, there is a need for an improved system with minimal hands-on requirements and short run times.
Objectives: In this study, the performance characteristics of the FilmArray® BCID Panel kit were evaluated to assess the efficiency of the kit against an existing system used for identification and antimicrobial susceptibility of organisms from blood cultures.
Methods: Positive blood cultures that had initially been received from hospitalised patients of a large quaternary referral hospital in Durban, South Africa were processed as per routine protocol at its Medical Microbiology Laboratory. Positive blood cultures were processed on the FilmArray BCID Panel kit in parallel with the routine sample processing. Inferences were then drawn from results obtained.
Results: Organism detection by the FilmArray BCID panel was accurate at 92.6% when organisms that were on the repertoire of the kit were considered, compared to the combination methods (reference method used in the study laboratory). Detection of the antimicrobial resistance markers provided by the panel and reference method demonstrated 100% consistency. Blood cultures with a single organism were accurately identified at 93.8% by FilmArray, while blood cultures with more than one organism were identified at 85.7%.
Conclusion: The FilmArray BCID Panel kit is valuable for detection of organisms and markers of antibiotic resistance for an extensive range of organisms.
Experimental phage therapy against haematogenous multi-drug resistant Staphylococcus aureus pneumonia in mice : original researchSource: African Journal of Laboratory Medicine 5, pp 1 –7 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.435More Less
Background: Community-acquired haematogenous Staphylococcus aureus pneumonia is a rare infection, though it can be acquired nosocomially. Currently, antibiotics used against S. aureus pneumonia have shown reduced efficacy. Thus, there is need for an alternative therapy against multidrug-resistant S. aureus (MDRSA) strains in the community.
Objective: We sought to determine the efficacy of environmentally-obtained S. aureus lytic phage against haematogenous MDRSA pneumonia in mice.
Methods: Phages and MDRSA were isolated from sewage samples collected within Nairobi County, Kenya. Isolated S. aureus bacteria were screened for resistance against ceftazidime, oxacillin, vancomycin, netilmicin, gentamicin, erythromycin, trimethroprim-sulfamethoxazole and cefuroxime. Thirty BALB/c mice aged six to eight weeks were randomly assigned into three groups: the MDRSA-infection group (n = 20), the phage-infection group (n = 5) and the non-infection group (n = 5). Mice were infected with either MDRSA or phage (108 CFU/mL) and treated after 72 hours with a single dose of clindamycin (8 mg/kg/bwt) or 108 PFU/mL of phage or a combination therapy (clindamycin and phage). The efficacy of phage, clindamycin or clindamycin with phage combination was determined using resolution of lung pathologyand bacterial load in lung homogenates.
Results: The viable MDRSA count was 0.5 ± 0.2 log10 CFU/gm in the phage-treated group,4.4 ± 0.2 log10 CFU/gm in the clindamycin-treated group and 4.0 ± 0.2 log10 CFU/gm in the combination-treated group. The efficacy of phage therapy was significantly different from other therapeutic modes (p = 0 lt; 0.0001). Histology showed that the mice treated with phagedid not develop pneumonia.
Conclusion: Phage therapy is effective against haematogenous MDRSA infection. Thus, it can be explored as an alternative treatment method.
Source: African Journal of Laboratory Medicine 5, pp 1 –6 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.433More Less
Background: Use of rapid diagnostic tests for HIV and syphilis has increased remarkably in the last decade. As new rapid diagnostic tests become available, there is a continuous need to assess their performance and operational characteristics prior to use in clinical settings.
Objectives: In this study, we evaluated the performance of the Chembio Dual Path Platform (DPP®) HIVâ??Syphilis Assay to accurately diagnose HIV, syphilis, and HIV/syphilis co-infection.
Method: In 2013, 990 serum samples from the Georgia Public Health Laboratory in Atlanta, Georgia, United States were characterised for HIV and syphilis and used to evaluate the platform. HIV reference testing combined third-generation Enzyme Immunoassay and Western Blot, whereas reference testing for syphilis was conducted by the Treponema pallidum passive particle agglutination method and the TrepSure assay. We assessed the sensitivity and specificity of the DPP assay on this panel by comparing results with the HIV and syphilis reference testing algorithms.
Results: For HIV, sensitivity was 99.8% and specificity was 98.4%; for syphilis, sensitivity was 98.8% and specificity was 99.4%. Of the 348 co-infected sera, 344 (98.9%) were detected accurately by the DPP assay, but 11 specimens had false-positive results (9 HIV and 2 syphilis) due to weak reactivity.
Conclusion: In this evaluation, the Chembio DPP HIVâ??Syphilis Assay had high sensitivity and specificity for detecting both HIV and treponemal antibodies. Our results indicate that this assay could have a significant impact on the simultaneous screening of HIV and syphilis using a single test device for high-risk populations or pregnant women needing timely care and treatment.
Performance of Kalon herpes simplex virus2 assay using dried blood spots among young women in Uganda : brief reportSource: African Journal of Laboratory Medicine 5, pp 1 –4 (2016) http://dx.doi.org/http://dx.doi.org/10.4102/ajlm.v5i1.429More Less
This study evaluated the performance of the Kalon Biological HSV2 IgG enzyme-linked immunosorbent assay (Kalon Biological Ltd, Surrey, United Kingdom) on dried blood spots (DBS) of various dilutions compared with plasma from young women aged 18-24 years in Uganda. We estimated the sensitivity and specificity of three DBS dilutions using plasma as the reference. All three evaluated DBS dilutions yielded low sensitivities and specificities, with DBS 1:2 yielding the highest concurrence. Other herpes simplex virus type 2 assays should be examined with regard to their utility for testing DBS.