Browsing by Author "Maritz, Jean"
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- ItemHIV testing and antiretroviral therapy initiation at birth : views from a primary care setting in Khayelitsha(AOSIS Publishing, 2015-04-28) Nelson, Aurelie; Maritz, Jean; Giddy, Janet; Frigati, Lisa; Rabie, Helena; Van Cutsem, Gilles; Mutseyekwa, Tabitha; Jange, Nomfusi; Bernheimer, Jonathan; Cotton, Mark F.; Cox, VivianNo abstract available.
- ItemHIV-1 RNA testing of pooled dried blood spots is feasible to diagnose acute HIV infection in resource limited settings(Medpharm Publications, 2018) Dowling, Wentzel; Veldsman, Kirsten; Katusiime, Mary Grace; Maritz, Jean; Bock, Peter; Meehan, Sue-Ann; Schalkwyk, Marije Van; Cotton, Mark F.; Preiser, Wolfgang; Van Zyl, Gert U.Objectives: Rapid human immunodeficiency virus (HIV) antibody tests, routinely used for diagnosis in adults and older children in resource-limited settings (RLS), do not detect early HIV infections prior to seroconversion or when antibody levels are still low. Nucleic acid amplification to detect HIV-1 RNA is the most sensitive method for acute HIV infection diagnosis, but is costly. We therefore investigated HIV- 1 RNA testing of pooled dried blood spots (DBS) to diagnose acute HIV infection. Design: Laboratory-based investigation. Methods: DBS were collected from HIV-1 Voluntary Counselling and Testing (HVCT) clients who tested negative on the Advanced QualityTM HIV antibody rapid test. DBS samples from five participants were pooled and tested on the COBAS AmpliPrep/COBAS TaqMan HIV-1 (CAP/CTM) Test v2. Individual DBS were tested when pools tested positive (> 200 RNA copies/ml). Acute infection was confirmed by HIV viral load testing, two fourth-generation HIV serological assays, and Geenius™ HIV 1/2 Assay for antibody band identification. Results: Of 482 participants who were tested, one (0.2%) had acute HIV infection: Fourth generation serology was low-level positive, the plasma HIV viral load was 15 929 HIV-1 RNA copies/ml, gp160 and gp41 antibody bands were positive and the p31 band was negative, indicating a Fiebig Stage 5 infection. Conclusions: Pooled DBS HIV-1 RNA testing is efficient compared to individual testing for acute HIV infection diagnosis. Early identification of participants with acute HIV infection facilitates immediate initiation of antiretroviral therapy to improve immune recovery and prevent transmission to others.
- ItemThe impact of cerebrospinal fluid viral analysis on empiric antibiotic use in children admitted to Tygerberg Children’s hospital with suspected meningitis(Medpharm Publications, 2018-10) Kruger, Irma; Maritz, Jean; Finlayson, HeatherBackground: Viral meningitis is the most common form of aseptic meningitis and requires minimal investigation and treatment. Polymerase chain reaction (PCR) has become the ‘gold standard’ for identifying viruses in cerebrospinal fluid and can provide rapid results. The objective of the study was to describe the aetiology and epidemiology of viral meningitis at Tygerberg Children’s Hospital, as well as the impact of a positive cerebral spinal fluid (CSF) viral panel on the duration of empiric antibiotic treatment. Methods: This was a retrospective folder review of all children aged between 29 days and 13 years who had a CSF specimen on which a viral analysis was performed from January 1, 2010 to December 31, 2014. Results: A total of 288 specimens were identified from the laboratory database. Seventy-nine specimens were presented for data analysis. Thirty-seven specimens had a positive viral analysis. The median age was 11.3 months (IQR 3.7–49.16 months). The microscopy and chemistry results were similar for the two groups except for the CSF lymphocyte count, which was significantly higher in the group with a positive CSF viral analysis compared to those with a negative CSF viral analysis (median 52 vs. 12 × 106/l, p = 0.005). The most common identified virus was Epstein–Barr virus (EBV) (23%), followed by enterovirus (17%). Children with a positive viral analysis tended to receive antibiotics for longer than those who had negative results (p = 0.223). Conclusion: The addition of CSF viral analysis could be helpful in the management of children with meningitis, but at present appears to have little impact on the length of antibiotic use.
- ItemIrreproducible positive results on the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test are qualitatively different from confirmed positive results(2013-10) Maritz, Jean; Van Zyl, Gert Uves; Preiser, WolfgangCriteria that define low positive results on the COBAS® AmpliPrep/COBAS® TaqMan (CAP/CTM) HIV- 1 Qual test as inconclusive have been adopted by all academic centres in South Africa that conduct infant HIV PCR, following previous investigations that showed poor specificity of these results. Retesting all these specimens has considerable cost implications. It was therefore attempted to better characterise such inconclusive results, by comparing those that prove to be either negative or positive on follow-up testing. This retrospective, laboratory-based study found that 193 of 211 (91.5%) patients with with previous inconclusive results (defined as reported positive by CAP/CTM but with cycle threshold [Ct] values of >32 and/or fluorescence intensity [FI] values of <5) tested negative and only 18 (8.5%) positive using independently obtained follow-up samples after a median of 28 days). The only significant independent predictor of a later positive result was a higher FI value (3.326 vs. 0.495, p<0.0001), whereas Ct values were not independently predictive. Specimens from patients negative on follow-up testing were qualitatively different from specimens that proved to be true positive. As the lower FI values in false-positive compared to true-positive results are probably indicative of a non-specific signal, the incorporation of stringent amplification slope criteria in the assay’s test definition file may improve correct classification and thus reduce the need for repeat testing of a large number of inconclusive specimens.
- ItemMolecular characterisation and epidemiology of enterovirus-associated aseptic meningitis in the Western and Eastern Cape Provinces, South Africa 2018–2019(Elsevier B.V., 2021-04) Nkosi, Nokwazi; Preiser, Wolfgang; Van Zyl, Gert; Claassen, Mathilda; Cronje, Nadine; Maritz, Jean; Newman, Howard; McCarthy, Kerrigan; Ntshoe, Genevie; Essel, Vivien; Korsman, Stephen; Hardie, Diana; Smuts, HeidiBackground: Enteroviruses are amongst the most common causes of aseptic meningitis. Between November 2018 and May 2019, an outbreak of enterovirus-associated aseptic meningitis cases was noted in the Western and Eastern Cape Provinces, South Africa. Objectives: To describe the epidemiology and phylogeography of enterovirus infections during an aseptic meningitis outbreak in the Western and Eastern Cape Provinces of South Africa. Methods: Cerebrospinal fluid samples from suspected cases were screened using a polymerase chain reaction targeting the 5’UTR. Confirmed enterovirus-associated meningitis samples underwent molecular typing through species–specific VP1/VP2 primers and pan-species VP1 primers. Results: Between November 2018 and May 2019, 3497 suspected cases of aseptic meningitis were documented in the Western and Eastern Cape Provinces. Median age was 8 years (range 0–61), interquartile range (IQR=4–13 years), 405/735 (55%) male. 742/3497 (21%) cases were laboratory – confirmed enterovirus positive by routine diagnostic PCR targeting the 5’UTR. 128/742 (17%) underwent molecular typing by VP1 gene sequencing. Echovirus 4 (E4) was detected in 102/128 (80%) cases. Echovirus 9 was found in 7%, Coxsackievirus A13 in 3%. 10 genotypes contributed to the remaining 10% of cases. Synonymous mutations were found in most cases, with sporadic amino acid changes in 13 (12.7%) cases. Conclusion: The aseptic meningitis outbreak was associated with echovirus 4. Stool samples are valuable for molecular typing in CSF confirmed EV-associated aseptic meningitis.
- ItemPooled PCR testing of dried blood spots for infant HIV diagnosis is cost efficient and accurate(BMC (part of Springer Nature), 2019) Van Schalkwyk, Cari; Maritz, Jean; Van Zyl, Gert U.; Preiser, Wolfgang; Welte, AlexBackground: Access to qualitative HIV PCRs for early infant diagnosis (EID) is restricted in resource-limited settings due to cost. We hypothesised that pooling of dried blood spots (DBS), defined as combining multiple patient samples in a single test with subsequent individual testing of positive pools, would be cost saving while retaining clinical accuracy compared to individual patient testing. Methods: Cost savings: A model was developed to simulate reagent and consumable cost saving of pooled compared to individual sample testing. Daily sample/result data of a public health laboratory in South Africa were used to illustrate outputs from the model. Samples were randomly allocated to pools and the process was repeated 1000 times to measure variation in estimates due to this stochasticity. Clinical accuracy: 1170 patient samples were tested using the Roche CAP/CTM Qual assay in pools of five 50 μl DBS. Negative pools comprised DBS previously tested in single reactions; positive pools included 1 positive sample. Results: Pooling would have saved 64% of laboratory costs in 2015. The model is published as an R-based web tool, into which the user enters sample/positivity estimates and workflow management parameters to obtain cost saving estimates at an optimal pool size. Sensitivity of pooled testing was 98.8% overall; 100% for strongly reactive pools. One pool tested false positive which would not impact clinical specificity as individual patient testing is performed prior to reporting. Conclusions: Pooled PCR testing for EID remains accurate and dramatically reduces costs in settings with moderate to low prevalence rates and sufficient sample numbers.
- ItemRecommendations for the management of indeterminate HIV PCR results within South Africa’s early infant diagnosis programme(AOSIS Publishing, 2016-05-13) Mazanderani, Ahmad Haeri; Technau, Karl-Gunter; Hsiao, Nei-yuan; Maritz, Jean; Carmona, Sergio; Sherman, Gayle G.ENGLISH ABSTRACT: Indeterminate HIV PCR results represent missed diagnostic opportunities within South Africa's early infant diagnosis (EID) programme. These results not only delay diagnosis and appropriate management but are also a source of confusion and apprehension amongst clinicians and caregivers. We describe the extent of indeterminate HIV PCR results within South Africa's EID programme and provide recommendations for the management of these cases, both in terms of laboratory practice and the clinical care of the infants.