Mercury (Hg) stored in vegetation and soils is known to be released to the atmosphere during wildfires, increasing atmospheric stores and altering terrestrial budgets. Increased erosion and transport of sediments is well-documented in burned watersheds, both immediately post-fire and as the watershed recovers; however, understanding post-fire mobilization of soil Hg within burned watersheds remains elusive. The goal of the current study is to better understand the impact of wildfire on soil-bound Hg during the immediate post-fire period as well as during recovery, in order to assess the potential for sediment-driven transport to and within surface waters in burned watersheds. Soils were collected from three southern California watersheds of similar vegetation and soil characteristics that experienced wildfire. Sampling in one of these watersheds was extended for several seasons (1.5 years) in order to investigate temporal changes in soil Hg concentrations. Laboratory analysis included bulk soil total Hg concentrations and total organic carbon of burned and unburned samples. Soils were also fractionated into a subset of grain sizes with analysis of Hg on each fraction. Low Hg concentrations were observed in surface soils immediately post-fire. Accumulation of Hg coincident with moderate vegetative recovery was observed in the burned surface soils 1 year following the fire, and mobilization was also noted during the second winter (rainy) season. Hg concentrations were highest in the fine-grained fraction of unburned soils; however, in the burned soils, the distribution of soil-bound Hg was less influenced by grain size. The accelerated accumulation of Hg observed in the burned soils, along with the elevated risk of erosion, could result in increased delivery of organic- or particulate-bound Hg to surface waters in post-fire systems.

BACKGROUND: Initiation of antiretroviral therapy (ART) following diagnosis of HIV infection at birth is an emerging area of paediatric HIV care. We present outcomes of HIV-infected infants identified at birth at Rahima Moosa Mother and Child Hospital in Johannesburg, South Africa. METHODS: From September, 2013 (era 1), only high-risk HIV-exposed infants were offered diagnostic HIV PCR tests at birth. From June, 2014 (era 2), all HIV-exposed infants were offered laboratory-based diagnostic PCR tests. From October, 2014 (era 3), point of care (POC) diagnostic PCR tests were also done if staff availability allowed. We describe time to ART initiation, mortality, retention in care, and viral suppression among the HIV-infected infants identified across these eras. FINDINGS: We tested 5449 HIV-exposed infants who were born between Sept 1, 2013, and June 30, 2016. 88 neonates with confirmed HIV infection were identified and included in the study, of which 86 (98%) started ART. Median age at ART initiation decreased from 9 days (IQR 6-25) in eras 1 and 2 to 2 days (1-8) in era 3. In era 3, more neonates who were co-tested with POC testing started ART within 48 h of birth (29 [83%] of 35; median 1 day [IQR 1-2]) than infants who were not co-tested (one [4%] of 29; median 6 days [5-10]). The probability of mortality by 12 months across the eras was 14% (95% CI 8-24) and did not differ by era. Of the 72 infants who survived and initiated ART at the site, 56 (78%) were retained at 12 months. Of the 56 infants retained in care, 40 (71%) had a viral load less than 400 copies per mL at 12 months, with no differences between eras (p=0·23). INTERPRETATION: HIV-infected infants can be identified at birth and ART can be initiated within hours to days. Although most infants in our cohort started ART, mortality remained unacceptably high with suboptimal retention and viral suppression. Reducing mortality and improving retention and viral suppression remain urgent priorities. FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institute of Allergy and Infectious Disease, National Institutes of Health, USAID/PEPfAR, and the South African National HIV Programme.

Disclosure to children living with HIV (CLHIV) about their own status is associated with positive outcomes such as treatment adherence, but prior cross-sectional studies in sub-Saharan Africa report disclosure rates of <50%. This study aims to assess pediatric disclosure over time. 548 CLHIV were followed from 2/2013-4/2018 in Johannesburg, South Africa. Cumulative incidence of disclosure was calculated with Kaplan-Meier analysis, and disclosure characteristics assessed with a Cox model. By end of follow-up, cumulative disclosure was 70.3% (95% confidence interval: 60.0-79.9). Median age at disclosure was 9 years (range: 3-13). Baseline predictors of disclosure included older child age and the child having a history of going hungry. Prior to disclosure, 98.0% of caregivers who disclosed had conversed with their child about their illness or an HIV-related topic, or their child had asked about HIV, versus 88.6% of caregivers who never disclosed. While many children did not receive disclosure during this relatively large, longitudinal study of South African CLHIV, caregivers who had not yet disclosed may have been preparing to do so by discussing their childs health or HIV generally with their child. This highlights the need for clinicians to consistently support caregivers throughout the incremental disclosure process.

Background

Studies in adults and children suggested that starting antiretroviral therapy (ART) soon after infection positively influences early events in HIV infection raising the possibility that remission may be achieved in some.

Methods

We designed an analytic treatment interruption (ATI) trial to test the hypothesis that a sizable minority of HIV-infected neonates who initiated ART <14 days of birth and maintained on ART would be able to maintain viral suppression when ART was withdrawn. To yield the target cohort for this trial, 73 HIV-infected neonates identified at one hospital in Johannesburg, South Africa, were initiated on ART <14 days of birth and maintained on ART tracking viral load (VL) decline and immune recovery (clinicaltrials.gov # NCT02431975).

Findings

Three HIV-infected infants (4.1%) died and nine (12.3%) were lost to follow-up before 48 weeks of age. Of those surviving on study, 52.5% attained and sustained VL <50 copies/ml and half of these sustained CD4+ T-cell percentage >30% which were the primary entry criteria for the ATI trial. Proportions achieving ATI eligibility criteria were similar in the 46 infants starting ART <48 h (19.6%) to 27 infants starting 2-14 days (25.9%) (p = 0.567).

Interpretation

Very early ART on its own, using regimens available when the trial was designed, is insufficient to attain minimum entry criteria needed to justify our trial of ART interruption. Decisions about how quickly to start ART should be based on optimizing standard clinical outcomes rather than with the expectation that remission can be attained.

Funding

NICHD/NIAID (U01HD080441), South African Research Chairs Initiative of DST and NRF (South Africa).