Low prevalence of hepatitis B virus infection in HIV-uninfected pregnant women in Cape Town, South Africa: implications for oral pre-exposure prophylaxis roll out

Background

Oral daily preexposure prophylaxis (PrEP) using emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) is recommended as standard of care for prevention in individuals at high risk for HIV infection, including pregnant and postpartum cisgender women. FTC/TDF is also active against hepatitis B virus (HBV); however, concern has been raised that providing PrEP to individuals infected with HBV could lead to hepatitis flares and liver injury, especially in the setting of suboptimal PrEP use.

Methods

We conducted a cross-sectional analysis of baseline data from the PrEP in pregnant and postpartum women (PrEP-PP) cohort study from February 2020–March 2022 in one antenatal care clinic in Cape Town, South Africa (SA) to evaluate: (1) the field performance of a point of care test (POCT) (Determine II, Abbott Inc., Japan) for diagnosis of hepatitis B surface antigen (HBsAg) in a maternity setting, (2) the prevalence of HBV in a cohort of pregnant women not living with HIV.

Results

We enrolled 1194 HIV sero-negative pregnant women at their first antenatal visit. Median age was 26 years (IQR = 22–31 years); 52% were born before 1995 (before universal HBV vaccination had started in South Africa). Median gestational age was 22 weeks (IQR = 16–30 weeks). There were 8 POCT and laboratory confirmed HBV cases among 1194 women. The overall prevalence of 0.67% (95% CI = 0.34–1.32%). In women born before 1995, 8 of 622 women were diagnosed with HBsAg; the prevalence was 1.29% (95% CI = 0.65–2.52%), and in women born in 1995 or after (n = 572); the prevalence was 0% (95% CI = 0.0–0.67%). We confirmed the test results in 99.8% of the rapid HBsAg (Determine II). Sensitivity was 100% (95% CI = 68–100%). Specificity was 100% (95% CI = 99.67–100%).

Conclusion

The prevalence of HBV was very low in pregnant women not living with HIV and was only in women born before the HBV vaccine was included in the Expanded Program of Immunization. The Determine II POCT HBsAg showed excellent performance against the laboratory assay. HBV screening should not be a barrier to starting PrEP in the context of high HIV risk communities.

72 weeks post-partum follow-up of dolutegravir versus efavirenz initiated in late pregnancy (DolPHIN-2): an open-label, randomised controlled study

BACKGROUND

Late initiation of antiretrovirals in pregnancy is associated with increased risk of perinatal transmission and higher infant mortality. We report the final 72-week postpartum results for efficacy and safety of dolutegravir-based compared with efavirenz-based regimens in mothers and infants.

METHODS

DolPHIN-2 was a randomised, open-label trial. Pregnant women in South Africa and Uganda aged at least 18 years, with untreated but confirmed HIV infection and an estimated gestation of at least 28 weeks, initiating antiretroviral therapy in third trimester were eligible for inclusion. Eligible women were randomly assigned (1:1) to receive either dolutegravir-based (50 mg dolutegravir, 300 mg tenofovir disoproxil fumarate, and either 200 mg emtricitabine in South Africa or 300 mg lamivudine in Uganda) or efavirenz-based (fixed dose combination 600 mg tenofovir disoproxil fumarate plus either emtricitabine in South Africa or lamivudine in Uganda) therapy. The primary efficacy outcome was the time to a viral load of less than 50 copies per mL measured at 6, 12, 24, 48, and 72 weeks postpartum with a Cox model adjusting for viral load and CD4 cell count. Safety endpoints were summarised by the number of women and infants with events. This trial is registered with ClinicalTrials.gov, NCT03249181.

FINDINGS

Between Jan 23 and Aug 15, 2018, 280 women were screened for inclusion, of whom 268 (96%) women were randomly assigned: 133 (50%) to the efavirenz group and 135 (50%) to the dolutegravir group. 250 (93%; 125 [50%] in the efavirenz group and 125 [50%] in the dolutegravir group) women were included in the intention-to-treat analysis of efficacy. Median time to viral load of less than 50 copies per mL was 4·1 weeks (IQR 4·0-5·1) in the dolutegravir group compared with 12·1 weeks (10·7-13·3) in the efavirenz group (adjusted hazard ratio [HR] 1·93 [95% CI 1·5-2·5]). At 72 weeks postpartum, 116 (93%) mothers in the dolutegravir group and 114 (91%) in the efavirenz group had a viral load of less than 50 copies per mL. Of 57 (21%) mothers with a severe adverse event, three (2%) in the dolutegravir group and five (4%) in the efavirenz group were related to the drug (dolutegravir drug-related events were one woman each with suicidal ideation, suicide attempt, herpes zoster meningitis; efavirenz drug-related events were one woman each with suicide attempt and liver cirrhosis, and three people with drug-induced liver injury). Of 136 (56%) infants in whom severe adverse events were recorded, none were related to the study drugs. In addition to the three infant HIV infections detected at birth in the dolutegravir group that have been previously reported, an additional transmission in the efavirenz group occurred during breastfeeding despite optimal maternal viral suppression and serial negative infant tests in the first year of life.

INTERPRETATION

Dolutegravir was safe and well tolerated, supporting updated WHO treatment recommendations in pregnant and breastfeeding women. Infant HIV transmissions can occur during breastfeeding despite persistently undetectable maternal viral load highlighting the need for continued infant testing.

FUNDING

Unitaid.

Risk-based screening to identify reproductive tract infection among HIV-infected women desiring use of intrauterine contraceptives

BACKGROUND

Reproductive tract infections (RTIs) are a major cause of morbidity and mortality, yet RTI testing remains limited in resource-constrained settings. We assessed performance of an existing RTI risk assessment screening tool among women living with HIV (WLHIV) considering intrauterine contraceptive (IUC) use.

METHODS

We conducted a cross-sectional analysis among WLHIV screened for participation in an IUC trial in Cape Town, South Africa (NCT01721798). RTI testing included Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and bacterial vaginosis. Tool scoring was based on five separately scored criteria: (1) age under 25 years, (2) cohabitation with a partner, (3) secondary education, (4) self-reported intermenstrual bleeding and (5) number of current sexual partners and condom use frequency (score 0-5). We assessed tool performance in detecting RTI at 0 vs 1-5, 0-1 vs 2-5 and 0-2 vs 3-5 score thresholds.

RESULTS

Of 303 women, 52% (n=157) reported antiretroviral therapy use and median age was 31 years. The prevalence of any RTI was 38% (gonorrhoea=7%, chlamydia=11%, trichomoniasis=12% and bacterial vaginosis=18%) and 8% of women had multiple RTIs. Overall, 4%, 27% and 69% of women had screening tool scores of 0, 1 or 2+, respectively. At a threshold of at least one scored criterion, the tool demonstrated high sensitivities (95%-97%) but low specificities (3%-4%) for detecting any RTI. Increasing the score threshold and/or inclusion of abnormal vaginal discharge marginally improved specificity.

CONCLUSION

The prevalence of RTIs observed in this population was high, and the screening tool had no discriminatory power to detect prevalent RTIs.

ART Adherence, Resistance, and Long-term HIV Viral Suppression in Postpartum Women

HIV+ South African women who achieved viral suppression during routine antenatal care, but later experienced a viremic episode (viral load >1000 copies/mL), were examined for presence of antiretrovirals and classified as "nonadherers" or "suboptimal adherers." Women were tested for drug resistance mutations (DRMs) at several time points and underwent viral load testing 36-60 months postpartum. Suboptimal adherers were more likely to have DRM detected during their viremic episode (P = .03) and at a subsequent viremic time point (P = .05). There was no difference in levels of viral suppression 36-60 months later in women with DRM detected vs women who had no evidence of DRM (P = .5).

High human papillomavirus (HPV) prevalence in South African adolescents and young women encourages expanded HPV vaccination campaigns

The objectives of the study were to investigate prevalence of cervical human papillomavirus (HPV) genotypes to inform HPV vaccination strategy in South Africa and to study factors associated with HPV prevalence. Sexually active, HIV-negative women, aged 16-22 years recruited from Soweto (n = 143) and Cape Town (n = 148) were tested for cervical HPV and other genital infections. Overall HPV prevalence was 66.7% (194/291) in young women. Cape Town women were more likely to have multiple HPV infections than the Soweto women (48.0%, 71/148 versus 35.0%, 50/143 respectively, p = 0.033) and probable HR-HPV types (34.5%, 51/148 versus 21.7%, 31/143 respectively, p = 0.022). The most frequently detected HPV types were HPV-16 (11.7%), HPV-58 (10.3%), HPV-51 (8.9%), HPV-66 (8.6%), HPV-18 and HPV-81 (7.6% each). HPV types targeted by the bivalent HPV vaccine (HPV-16/18) were detected in 18.6% (54/291) of women, while those in the quadrivalent vaccine (HPV-6/11/16/18) were detected in 24.7% (72/291) of women; and those in the nonavalent vaccine (HPV-6/11/16/18/31/33/45/52/58) were detected in 38.5% (112/291) of women. In a multivariable analysis, bacterial vaginosis remained significantly associated with HPV infection (OR: 4.0, 95% CI: 1.4-12.6). Women were more likely to be HPV positive if they had received treatment for STI during the past 6-months (OR: 3.4, 95% CI: 1.1-12.4) or if they had ever been pregnant (OR: 2.3, 95% CI: 1.1-5.5). Compared to women who reported only one sexual partner, those with increased number of lifetime sex partners were more likely to have HPV (4-10 partners: OR: 2.9, 95% CI: 1.1-8.0). The high prevalence of HPV types targeted by the nonavalent HPV vaccine encourages the introduction of this vaccine and catch-up HPV vaccination campaigns in South Africa. The high burden of BV and concurrent STIs also highlights the need to improve the prevention and appropriate management of sexually-acquired and other genital tract infections in South African youth.

Discrete Fourier preprocessing transforms for the binary phase-only filter

Two useful discrete Fourier preprocessing transforms (DFPTs), say, class 1 and class 2, are applied to the binary phase-only filter. The class-1 DFPT is very close to the discrete Fourier transform (DFT); therefore it preserves the properties similar to those for the DFT. The Class-2 DFPT's are location sensitive and are able to recognize the partial-shape-like input pattern that is the partial set of the pattern in the filter. The Class-2 DFPT's generate a delta-function-like correlation peak whose intensity is larger than that obtained by the DFT. These are different from the DFT-based binary phase-only filter. The elements of the DFPT's are very simple, containing only ±1 and 0; some even contain sparse ±1 values and plenty of zeros. Therefore the DFPT's are suitable for either optical or electrical implementation.