Browsing by Author "Andersson, Monique Ingrid"
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- ItemHepatitis B virus drug resistance mutations in HIV/HBV co-infected children in Windhoek, Namibia(Public Library of Science, 2020-09-11) Tchuem, Cynthia Raissa Tamandjou; Brandt, Laura; Nel, Etienne De la Rey; Cotton, Mark Fredric; Matthews, Philippa; Kaindjee-Tjituka, Francina; Preiser, Wolfgang; Andersson, Monique IngridENGLISH ABSTRACT: In patients who are HIV infected, hepatitis B virus (HBV) infection is an important co-morbidity. However, antiretroviral options for HIV/HBV co-infected children are limited and, at the time of this study, only included lamivudine. These children may remain on this regimen for many years until late adolescence. They are at high risk of developing HBV drug resistance and uncontrolled HBV disease. The aim of this study was to characterize HBV infection in HIV/HBV co-infected children. Known HIV-infected/HBsAg-positive children, previously exposed to lamivudine monotherapy against HBV, and their mothers were recruited at the Katutura Hospital paediatric HIV clinic in Windhoek, Namibia. Dried blood spot and serum samples were collected for HBV characterization and serological testing, respectively. Fifteen children and six mothers participated in the study. Eight of the 15 children (53.3%) tested HBV DNA positive; all eight children were on lamivudine-based ART. Lamivudine-associated resistance variants, together with immune escape mutants in the surface gene, were identified in all eight children. Resistance mutations included rtL80I, rtV173L, rtL180M, rtM204I/V and the overlapping sE164D, sW182*, sI195M and sW196LS variants. HBV strains belonged to genotypes E (6/8, 75%) and D3 (2/8, 25%). Further analysis of the HBV core promoter region revealed mutations associated with reduced expression of HBeAg protein and hepatocarcinogenesis. All six mothers, on HBV-active ART containing tenofovir and lamivudine, tested HBV DNA negative. This study confirms the importance of screening HIV-infected children for HBV and ensuring equity of drug access to effective HBV treatment if co-infected.
- ItemThe impact of revised PMTCT guidelines : a view from a public sector ARV clinic in Cape Town, South Africa(Lippincott Williams & Wilkins, 2013-06) Van Schalkwyk, Marije; Andersson, Monique Ingrid; Zeier, Michele Desire; La Grange, Marina; Taljaard, Johannes Jakobus; Theron, Gerhard BarnardBackground: In April 2010, revised Prevention of Mother-to-Child Transmission guidelines were implemented in South Africa, advising fast-tracked lifelong highly active antiretroviral therapy (HAART) initiation at a higher CD4 count (≤350 cells per microliter). This study describes the impact of these changes on the management of pregnant women who initiated HAART at Tygerberg Hospital, Cape Town. Methods: We conducted a retrospective review of all women who initiated HAART in pregnancy at the Tygerberg Hospital between January 2008 and December 2010. Year cohorts were compared. Results: Two hundred and fifty HIV-infected women were included in the study and stratified by HAART initiation year: 2008:N = 82, 2009:N = 71, 2010:N = 97. There were no differences between the groups in age or parity. Median booking CD4 count was 155 cells per microliter [interquartile range (IQR) 107–187], 157 cells per microliter (IQR 104–206) and 208 cells per microliter (IQR 138–270), respectively (P < 0.001). Median gestation at HAART initiation was 31 weeks (IQR 27–35), 30 weeks (IQR 26–34), and 25 weeks (IQR 21–31; P < 0.001). HIV transmission rates were 3/65 (4.6%), 4/57 (7.0%), and 0/90 (0.0%; P = 0.021). Women <8 weeks on HAART before delivery were more likely to transmit than women ≥8 weeks [odds ratio 9.69; 95% confidence interval 1.66 to 56.58; P = 0.017]. Ninety-four (37.6%) women were lost to follow-up, 18.4% within 28 days of delivery. Conclusions: The positive impact of the new Prevention of Mother-to-Child Transmission program is evident. A longer duration of HAART before delivery was associated with less transmission. However, the lost to follow-up rates remain concerning. Further research is needed to better understand the reasons for nonadherence and mechanisms to improve support for these women.
- ItemPoint-of-care screening for hepatitis B virus infection in pregnant women at an antenatal clinic : a South African experience(Public Library of Science, 2017) Chotun, Nafiisah; Preiser, Wolfgang; Van Rensburg, Christoffel Johannes; Fernandez, Pedro; Theron, Gerhard Barnard; Glebe, Dieter; Andersson, Monique IngridBackground & aims: Elimination of HIV and syphilis mother-to-child transmission (MTCT) has received much attention but little consideration has been given to the possibility of elimination of HBV MTCT. In sub-Saharan Africa, HBV vertical transmission continues to be reported and it remains an important public health problem. This study aimed to assess the feasibility of screening pregnant women for HBV using a point-of-care (POC) test and implementing interventions to prevent HBV MTCT. Methods: In this observational prospective cohort study, HIV-uninfected pregnant women who consented to testing were screened for HBV using a rapid POC test for HBsAg. Positive results were laboratory-confirmed and tested for HBV DNA and serological markers. Women with viral loads ≥ 20 000 IU/ml received tenofovir (TDF) treatment and all infants received birth-dose HBV vaccine. Two blood samples collected six months apart from HBV-exposed infants within their first year of life were tested for HBV DNA. Results: Of 144 women who were approached, 134 consented to participating (93% acceptance rate of HBV POC test). Six women tested positive for HBsAg (4.5%; 95% CI 0.99%–8.01%), all confirmed by laboratory testing. Two mothers, M1 and M4, were treated with TDF during their third trimester of pregnancy. Six HBV-exposed infants received the HBV vaccine within 24 hours of birth, of whom two were lost to follow-up and four (including the two born to M1 and M4) had undetectable levels of HBV DNA when tested at the two time points. Conclusion: We found that HBV screening using POC testing fulfilled the criteria considered necessary for implementation. It has acceptable performance, is inexpensive, reliable, and was well accepted by the study participants. Screening pregnant women as part of the HBV MTCT prevention strategy is therefore feasible in a South African clinical setting.
- ItemViral hepatitis B and C in HIV-exposed South African infants(BMC (part of Springer Nature), 2020) Tchuem, Cynthia Tamandjou; Cotton, Mark Fredric; Nel, Etienne; Tedder, Richard; Preiser, Wolfgang; Violari, Avy; Bobat, Raziya; Hovind, Laura; Aaron, Lisa; Montepiedra, Grace; Mitchell, Charles; Andersson, Monique IngridBackground: Whilst much attention is given to eliminating HIV mother-to-child transmission (MTCT), little has been done to ensure the same for hepatitis B virus (HBV) transmission. The introduction of HBV immunization at six weeks of age has reduced HBV horizontal transmission in South Africa. However, in order to eliminate HBV MTCT, further interventions are needed. The risk of hepatitis C virus (HCV) MTCT in HIV-infected (HIV+) African women is not yet well described. This study aimed to determine the rate of HBV and HCV vertical transmission in HIV-exposed infants in South Africa. Methods: Serum samples from infants enrolled in an isoniazid prevention study (P1041) were screened for HBV and HCV serology markers; screening was performed on samples collected at approximately 60 weeks of age of the infants. HBV DNA was quantified in HBsAg positive samples and HBV strains characterized through gene sequencing. All HCV antibody samples with inconclusive results underwent molecular testing. Results: Three of 821 infants were positive for both HBsAg and HBV DNA. All HBV strains belonged to HBV subgenotype A1. The rtM204I mutation associated with lamivudine resistance was identified in one infant, a second infant harboured the double A1762T/G1764A BCP mutation. Phylogenetic analysis showed clustering between mother and infant viral genomic sequences. Twenty-one of 821 HIV-exposed infants tested had inconclusive HCV antibody results, none were HCV PCR positive. Conclusions: This study suggests that HBV vertical transmission is likely to be occurring in HIV-exposed infants in South Africa.. A more robust strategy of HBV prevention, including birth dose vaccination, is required to eradicate HBV MTCT. HCV infection was not detected.