Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Declines in SARS-CoV-2 Transmission, Hospitalizations, and Mortality After Implementation of Mitigation Measures- Delaware, March-June 2020

Mitigation measures, including stay-at-home orders and public mask wearing, together with routine public health interventions such as case investigation with contact tracing and immediate self-quarantine after exposure, are recommended to prevent and control the transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (1-3). On March 11, the first COVID-19 case in Delaware was reported to the Delaware Division of Public Health (DPH). The state responded to ongoing community transmission with investigation of all identified cases (commencing March 11), issuance of statewide stay-at-home orders (March 24-June 1), a statewide public mask mandate (from April 28), and contact tracing (starting May 12). The relationship among implementation of mitigation strategies, case investigations, and contact tracing and COVID-19 incidence and associated hospitalization and mortality was examined during March-June 2020. Incidence declined by 82%, hospitalization by 88%, and mortality by 100% from late April to June 2020, as the mask mandate and contact tracing were added to case investigations and the stay-at-home order. Among 9,762 laboratory-confirmed COVID-19 cases reported during March 11-June 25, 2020, two thirds (6,527; 67%) of patients were interviewed, and 5,823 (60%) reported completing isolation. Among 2,834 contacts reported, 882 (31%) were interviewed and among these contacts, 721 (82%) reported completing quarantine. Implementation of mitigation measures, including mandated mask use coupled with public health interventions, was followed by reductions in COVID-19 incidence and associated hospitalizations and mortality. The combination of state-mandated community mitigation efforts and routine public health interventions can reduce the occurrence of new COVID-19 cases, hospitalizations, and deaths.

National-level effectiveness of ART to prevent early mother to child transmission of HIV in Namibia

Background

Namibia introduced the prevention of mother to child HIV transmission (MTCT) program in 2002 and lifelong antiretroviral therapy (ART) for pregnant women (option B-plus) in 2013. We sought to quantify MTCT measured at 4–12 weeks post-delivery.

Methods

During Aug 2014-Feb 2015, we recruited a nationally representative sample of 1040 pairs of mother and infant aged 4–12 weeks at routine immunizations in 60 public health clinics using two stage sampling approach. Of these, 864 HIV exposed infants had DNA-PCR HIV test results available. We defined an HIV exposed infant if born to an HIV-positive mother with documented status or diagnosed at enrollment using rapid HIV tests. Dried Blood Spots samples from HIV exposed infants were tested for HIV. Interview data and laboratory results were collected on smartphones and uploaded to a central database. We measured MTCT prevalence at 4–12 weeks post-delivery and evaluated associations between infant HIV infection and maternal and infant characteristics including maternal treatment and infant prophylaxis. All statistical analyses accounted for the survey design.

Results

Based on the 864 HIV exposed infants with test results available, nationally weighted early MTCT measured at 4–12 weeks post-delivery was 1.74% (95% confidence interval (CI): 1.00%-3.01%). Overall, 62% of mothers started ART pre-conception, 33.6% during pregnancy, 1.2% post-delivery and 3.2% never received ART. Mothers who started ART before pregnancy and during pregnancy had low MTCT prevalence, 0.78% (95% CI: 0.31%-1.96%) and 0.98% (95% CI: 0.33%-2.91%), respectively. MTCT rose to 4.13% (95% CI: 0.54%-25.68%) when the mother started ART after delivery and to 11.62% (95% CI: 4.07%-28.96%) when she never received ART. The lowest MTCT of 0.76% (95% CI: 0.36% - 1.61%) was achieved when mother received ART and ARV prophylaxis within 72hrs for infant and highest 22.32% (95%CI: 2.78% -74.25%) when neither mother nor infant received ARVs. After adjusting for mother’s age, maternal ART (Prevalence Ratio (PR) = 0.10, 95% CI: 0.03–0.29) and infant ARV prophylaxis (PR = 0.32, 95% CI: 0.10–0.998) remained strong predictors of HIV transmission.

Conclusion

As of 2015, Namibia achieved MTCT of 1.74%, measured at 4–12 weeks post-delivery. Women already on ART pre-conception had the lowest prevalence of MTCT emphasizing the importance of early HIV diagnosis and treatment initiation before pregnancy. Studies are needed to measure MTCT and maternal HIV seroconversion during breastfeeding.

Impact of breastfeeding, maternal antiretroviral treatment and health service factors on 18-month vertical transmission of HIV and HIV-free survival: results from a nationally representative HIV-exposed infant cohort, South Africa

BACKGROUND

We analysed the impact of breastfeeding, antiretroviral drugs and health service factors on cumulative (6 weeks to 18 months) vertical transmission of HIV (MTCT) and 'MTCT-or-death', in South Africa, and compared estimates with global impact criteria to validate MTCT elimination: (1) <5% final MTCT and (2) case rate ≤50 (new paediatric HIV infections/100 000 live births).

METHODS

9120 infants aged 6 weeks were enrolled in a nationally representative survey. Of 2811 HIV-exposed uninfected infants (HEU), 2644 enrolled into follow-up (at 3, 6, 9, 12, 15 and 18 months). Using Kaplan-Meier analysis and weighted survey domain-based Cox proportional hazards models, we estimated cumulative risk of MTCT and 'MTCT or death' and risk factors for time-to-event outcomes, adjusting for study design and loss-to-follow-up.

RESULTS

Cumulative (final) MTCT was 4.3% (95% CI 3.7% to 5.0%); case rate was 1290. Postnatal MTCT (>6 weeks to 18 months) was 1.7% (95% CI 1.2% to 2.4%). Cumulative 'MTCT-or-death' was 6.3% (95% CI 5.5% to 7.3%); 81% and 62% of cumulative MTCT and 'MTCT-or-death', respectively, occurred by 6 months. Postnatal MTCT increased with unknown maternal CD4-cell-count (adjusted HR (aHR 2.66 (1.5-5.6)), undocumented maternal HIV status (aHR 2.21 (1.0-4.7)) and exclusive (aHR 2.3 (1.0-5.2)) or mixed (aHR 3.7 (1.2-11.4)) breastfeeding. Cumulative 'MTCT-or death' increased in households with 'no refrigerator' (aHR 1.7 (1.1-2.9)) and decreased if infants used nevirapine at 6 weeks (aHR 0.4 (0.2-0.9)).

CONCLUSIONS

While the <5% final MTCT target was met, the case rate was 25-times above target. Systems are needed in the first 6 months post-delivery to optimise HEU health and fast-track ART initiation in newly diagnosed mothers.

Parametric attosecond pulse amplification far from the ionization threshold from high order harmonic generation in He. Opt Express 2020;28:24243-24252. [PMID: 32752406 DOI: 10.1364/oe.398595]

Parametric amplification of attosecond coherent pulses around 100 eV at the single-atom level is demonstrated for the first time by using the 3D time-dependent Schrödinger equation in high-harmonic generation processes from excited states of He⁺. We present the attosecond dynamics of the amplification process far from the ionization threshold and resolve the physics behind it. The amplification of a particular central photon energy requires the seed XUV pulses to be perfectly synchronized in time with the driving laser field for stimulated recombination to the He⁺ ground state and is only produced in a few specific laser cycles in agreement with the experimental measurements. Our simulations show that the amplified photon energy region can be controlled by varying the peak intensity of the laser field. Our results pave the way to the realization of compact attosecond pulse intense XUV lasers with broad applications.

Mother-To-Child Transmission of HIV in Adolescents and Young Women: Findings From a National Prospective Cohort Survey, Zimbabwe, 2013-2014

PURPOSE

We assessed 18-month cumulative mother-to-child HIV transmission (MTCT) risk and risk factors for no antiretroviral medication use during pregnancy among adolescent, young women, and adult mothers in Zimbabwe.

METHODS

We analyzed data from a prospective survey of 1,171 mother-infant pairs with HIV-exposed infants aged 4-12 weeks who were recruited from 151 immunization clinics from February to August 2013. HIV-exposed infants were followed until diagnosed with HIV, death, or age 18 months. Findings were weighted and adjusted for complex survey design and nonresponse.

RESULTS

The 18-month cumulative MTCT risk was highest among adolescent aged ≤19 years (12%) followed by young women aged 20-24 years (7.5%) and adult women aged ≥25 years (6.9%). Across these groups, more than 94% had ≥1 antenatal care visit by 21 weeks of gestation, more than 95% had ≥1 HIV test, and more than 98% knew their HIV status. Of known HIV-positive mothers, maternal antiretroviral medication coverage during pregnancy was 76.8% (95% confidence interval: 65.1-85.5), 83.8% (78.6-87.9), and 87.8% (84.6-90.4) among adolescent, young women, and adult mothers, respectively. Among HIV-positive mothers diagnosed prenatally, the adjusted odds ratio of no ARV use during pregnancy was increased among those who had no antenatal care attendance (adjusted odds ratio: 7.7 [3.7-16.0]), no HIV testing (7.3 [2.3-23.5]), no prepartum CD4 count testing (2.1 [1.3-3.4]), and maternal HIV identification during pregnancy (2.9 [1.8-4.8]). Age was not a risk factor.

CONCLUSIONS

With similar coverage of prevention of MTCT services, the 18-month cumulative MTCT risk was higher among adolescents and young women, compared with adults. Additional research should examine the causes to develop targeted interventions.

Impact of Timing of Antiretroviral Treatment and Birth Weight on Mother-to-Child Human Immunodeficiency Virus Transmission: Findings From an 18-Month Prospective Cohort of a Nationally Representative Sample of Mother-Infant Pairs During the Transition From Option A to Option B+ in Zimbabwe

Background

Preventing mother-to-child transmission of human immunodeficiency virus transmission (MTCT) depends on early initiation of antiretroviral therapy (ART). We report the 18-month MTCT risk during the transition from Option A to Option B+ in Zimbabwe, and assess whether ART preconception could eliminate MTCT in breastfeeding populations.

Methods

In 2013, we consecutively recruited a nationally representative sample of 6051 infants aged 4-12 weeks and their mothers from 151 immunization clinics using a multistage stratified cluster sampling method. We identified 1172 human immunodeficiency virus (HIV)-exposed infants and evaluated them at baseline and every 3 months until the child became HIV-infected, died, or reached age 18 months.

Results

The cumulative MTCT risk through 18 months postdelivery was 7.0%. Of the HIV-infected mothers, 35.3% started ART preconception, 28.9% during pregnancy, and 9.7% after delivery, and 16.0% received zidovudine during pregnancy. Compared to mothers without antiretroviral drug use, MTCT among those starting ART preconception and during pregnancy was lower by 88% (adjusted hazard ratio [aHR], 0.12; 95% confidence interval [CI], .06-.24) and 75% (aHR, 0.25; 95% CI, .14-.45), respectively. HIV-exposed infants with birth weight <2.5 kg (low birth weight) were 2.6-fold more likely to acquire HIV infection compared to those with birth weight ≥2.5 kg (aHR, 2.57; 95% CI, 1.44-4.59). Controlling for other factors, breastfeeding was not significantly associated with MTCT.

Conclusions

ART preconception has the highest impact on reducing MTCT, indicating that HIV-infected, reproductive-age women should be prioritized in "treat-all" strategies. HIV-infected mothers without ART use should be identified at the first immunization visit and treatment initiated to reduce postdelivery MTCT. MTCT risk is higher in mothers with low-birth-weight deliveries.

Longitudinal adherence to maternal antiretroviral therapy and infant Nevirapine prophylaxis from 6 weeks to 18 months postpartum amongst a cohort of mothers and infants in South Africa

BACKGROUND

Despite improved policies to prevent mother-to-child HIV transmission (MTCT), adherence to maternal antiretroviral therapy (ART) and infant Nevirapine prophylaxis (NVP) is low in South Africa. We describe ART adherence amongst a cohort of HIV-positive mothers and HIV-exposed but uninfected infants from 6 weeks until 18 months post-delivery and identify risk factors for nonadherence.

METHODS

Data were collected in 2012-2014 through a nationally representative survey of PMTCT effectiveness. Mother-infant pairs were enrolled during the infant's first immunization visit at 6 weeks. Mothers and HIV-exposed infants (2811 pairs) were followed to 18 months at 3-month intervals. Mothers who self-reported being on ART at 6 weeks postpartum (N = 1572 (55.9%)) and infants on NVP at 6 weeks (N = 2370 (84.3%)) were eligible for this analysis and information about their adherence was captured at each interview they attended thereafter. We defined nonadherence within each 3-month interval as self-report of missing > 5% of daily ART/NVP doses, estimated adherence using a Cox survival curve with Andersen & Gill setup for recurring events, and identified risk factors for nonadherence with an extended Cox regression model (separately for mothers and infants) in Stata 13. Results are not nationally representative as this is a subgroup analysis of the follow-up cohort.

RESULTS

Amongst mothers on ART at 6 weeks postpartum, cumulative adherence to maternal ART until 18 months was 63.4%. Among infants on NPV at 6 weeks postpartum, adherence to NVP was 74.5%.. Risk factors for nonadherence to maternal ART, controlling for other factors, included mother's age (16-24 years vs. ≥34 years, adjusted Hazard Ratio (aHR): 1.9, 95% CI: 1.4-2.5), nondisclosure of HIV status to anyone (nondisclosure vs. disclosure: aHR: 1.7, 95% CI: 1.3-2.1), and timing of ART initiation (initiated ART after delivery vs. initiated ART before delivery: aHR: 1.6, 95% CI: 1.3-2.0). Provincial variation was seen in nonadherence to infant NVP, controlling for other factors.

CONCLUSION

Maintaining ART adherence until 18 months postpartum remains a crucial challenge, with maternal ART adherence among the six week maternal ART cohort below 65% and infant NVP adherence among breastfeeding infants in this cohort below 75%.This is gravely concerning, given the global policy shift to lifelong ART amongst pregnant and lactating women, and the need for extended infant prophylaxis amongst mothers who are not virally suppressed. Our findings suggest that young mothers and mothers who do not disclose their status should be targeted with messages to improve adherence, and that late maternal ART initiation (after delivery) increases the risk of maternal nonadherence.

Prevalence of HIV-1 drug resistance amongst newly diagnosed HIV-infected infants age 4-8 weeks, enrolled in three nationally representative PMTCT effectiveness surveys, South Africa: 2010, 2011-12 and 2012-13

BACKGROUND

South Africa (SA) has expanded efforts to reduce mother-to-child transmission of HIV (MTCT) to less than 2% at six weeks after birth and to less than 5% at 18 months postpartum by 2016. Despite improved antiretroviral regimens and coverage between 2001 and 2016, there is little data on infant HIV drug resistance. This paper tracks the prevalence of HIV drug resistance patterns amongst HIV infected infants from three nationally representative studies that assessed the effectiveness of national programs to prevent MTCT (PMTCT). The first study was conducted in 2010 (under the dual therapy PMTCT policy), the second from 2011 to 12 (PMTCT Option A policy) and the third from 2012 to 13 (PMTCT Option A policy). From 2010 to 2013, infant non-nucleoside reverse transcriptase inhibitor (NNRTI) exposure increased from single dose to daily throughout breastfeeding; maternal nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI exposure increased with initiation of NNRTI-and NRTI- containing triple antiretroviral therapy (ART) earlier in gestation and at higher CD4 cell counts.

METHODS

Three nationally representative surveys were conducted in 2010, 2011-12 and 2012-13. During the surveys, mothers with known, unknown, or no exposure to antiretrovirals for PMTCT and their infants were included, and MTCT was measured. For this paper, infant dried blood spots (iDBS) from HIV PCR positive infants aged 4-8 weeks, with consent for additional iDBS testing, were analysed for HIV drug resistance at the National Institute of Communicable Diseases (NICD), SA, using an in-house assay validated by the Centers for Disease Control and Prevention (CDC). Total viral nucleic acid was extracted from 2 spots and amplified by nested PCR to generate a ~ 1 kb amplicon that was sequenced using Sanger sequencing technologies. Sequence assembly and editing was performed using RECall v3.

RESULTS

Overall, HIV-1 drug resistance was detected in 51% (95% Confidence interval (CI) [45-58%]) of HIV PCR positive infants, 37% (95% CI [28-47%]) in 2010, 64% (95% CI [53-74%]) in 2011 and 63% (95% CI [47-77%]) in 2012 (p < 0.0001), particularly to the NNRTI drug class. Pooled analyses across all three surveys demonstrated that infants whose mothers received ART showed the highest prevalence of resistance (74%); 26% (21/82) of HIV PCR positive infants with no or undocumented antiretroviral drug (ARV) exposure harboured NNRTI resistance.

CONCLUSIONS

These data demonstrate increasing NNRTI resistance amongst newly-diagnosed infants in a high HIV prevalence setting where maternal ART coverage increased across the years, starting earlier in gestation and at higher CD4 cell counts. This is worrying as lifelong maternal ART coverage for HIV positive pregnant and lactating women is increasing. Also of concern is that resistant virus was detected in HIV positive infants whose mothers were not exposed to ARVs, raising questions about circulating resistant virus. Numbers in this group were too small to assess trends over the three years.

What will it take for the Global Plan priority countries in Sub-Saharan Africa to eliminate mother-to-child transmission of HIV?

BACKGROUND

The 2016 'Start Free, Stay Free, AIDS Free' global agenda, builds on the 2011-2015 'Global Plan'. It prioritises 22 countries where 90% of the world's HIV-positive pregnant women live and aims to eliminate vertical  transmission of HIV (EMTCT) and to keep mothers alive. By 2019, no Global Plan priority country had achieved EMTCT; however, 11 non-priority countries had. This paper synthesises the characteristics of the first four countries validated for EMTCT, and of the 21 Global Plan priority countries located in Sub-Saharan Africa (SSA). We consider what drives vertical transmission of HIV (MTCT) in the 21 SSA Global Plan priority countries.

METHODS

A literature review, using PubMed, Science direct and the google search engine was conducted to obtain global and national-level information on current HIV-related context and health system characteristics of the first four EMTCT-validated countries and the 21 SSA Global Plan priority countries. Data representing only one clinic, hospital or region were excluded. Additionally, key global experts working on EMTCT were contacted to obtain clarification on published data. We applied three theories (the World Health Organisation's building blocks to strengthen health systems, van Olmen's Health System Dynamics framework and Baral's socio-ecological model for HIV risk) to understand and explain the differences between EMTCT-validated and non-validated countries. Additionally, structural equation modelling (SEM) and linear regression were used to explain associations between infant HIV exposure, access to antiretroviral therapy and two outcomes: (i) percent MTCT and (iii) number of new paediatric HIV infections per 100 000 live births (paediatric HIV case rate).

RESULTS

EMTCT-validated countries have lower HIV prevalence, less breastfeeding, fewer challenges around leadership, governance within the health sector or country, infrastructure and service delivery compared with Global Plan priority countries. Although by 2016 EMTCT-validated countries and Global Plan priority countries had adopted a public health approach to HIV prevention, recommending lifelong antiretroviral therapy (ART) for all HIV-positive pregnant and lactating women, EMCT-validated countries had also included contact tracing such as assisted partner notification, and had integrated maternal and child health (MCH) and sexual and reproductive health (SRH) services, with services for HIV infection, sexually transmitted infections, and viral hepatitis. Additionally, Global Plan priority countries have limited data on key SRH indicators such as unmet need for family planning, with variable coverage of antenatal care, HIV testing and triple antiretroviral therapy (ART) and very limited contact tracing. Structural equation modelling (SEM) and linear regression analysis demonstrated that ART access protects against percent MTCT (p<0.001); in simple linear regression it is 53% protective against percent MTCT. In contrast, SEM demonstrated that the case rate was driven by the number of HIV exposed infants (HEI) i.e. maternal HIV prevalence (p<0.001). In linear regression models, ART access alone explains only 17% of the case rate while HEI alone explains 81% of the case rate. In multiple regression, HEI and ART access accounts for 83% of the case rate, with HEI making the most contribution (coef. infant HIV exposure=82.8, 95% CI: 64.6, 101.1, p<0.001 vs coef. ART access=-3.0, 95% CI: -6.2, 0.3, p=0.074).

CONCLUSION

Reducing infant HIV exposure, is critical to reducing the paediatric HIV case rate; increasing ART access is critical to reduce percent MTCT. Additionally, our study of four validated countries underscores the importance of contact tracing, strengthening programme monitoring, leadership and governance, as these are potentially-modifiable factors.

Factors associated with non-attendance at scheduled infant follow-up visits in an observational cohort of HIV-exposed infants in South Africa, 2012-2014

Background

Since 2001 the South African guidelines to improve child health and prevent vertical HIV transmission recommended frequent infant follow-up with HIV testing at 18 months postpartum. We sought to understand non-attendance at scheduled follow-up study visits up to 18 months, and for the 18-month infant HIV test amongst a nationally representative sample of HIV exposed uninfected (HEU) infants from a high HIV-prevalence African setting.

Methods

Secondary analysis of data drawn from a nationally representative observational cohort study (conducted during October 2012 to September 2014) of HEU infants and their primary caregivers was undertaken. Participants were eligible (N = 2650) if they were 4–8 weeks old and HEU at enrolment. All enrolled infants were followed up every 3 months up to 18 months. Each follow-up visit was scheduled to coincide with each child’s routine health visit, where possible. The denominator at each time point comprised HEU infants who were alive and HIV-free at the previous visit. We assessed baseline maternal and early HIV care characteristics associated with the frequency of ‘Missed visits’ (MV-frequency), using a negative binomial regression model adjusting for the follow-up time in the study, and associated with missed visits at 18 months (18-month MV) using a logistic regression model.

Results

The proportion of eligible infants with MV was lowest at 3 months (32.7%) and 18 months (31.0%) and highest at 12 months (37.6%). HIV-positive mothers not on triple antiretroviral therapy (ART) by 6-weeks postpartum had a significantly increased occurrence rate of ‘MV-frequency’ (adjusted incidence rate ratio, 1.2 (95% confidence interval (CI), 1.1–1.4), p < 0.0001). Compared to those mothers with ART, these mothers also increased the risk of ‘18-month-MV’ (adjusted odds ratio, 1.3 (CI, 1.1–1.6), p = 0.006). Unknown infant nevirapine-intake status increased the rate of ‘MV-frequency’ (p = 0.02). Mothers > 24 years had a significantly reduced rate of ‘MV-frequency’ (p ≤ 0.01) and risk of ‘18-month-MV’ (p < 0.01) compared to younger women. Shorter travel time to health facility lowered the occurrence of ‘MV-frequency’ (p ≤ 0.004).

Conclusion

Late initiation of maternal ART and infant prophylaxis under the Option- A policy and extended travel time to clinics (measured at 6 weeks postpartum), contributed to higher postnatal MV rates. Mothers older than 24 years had lower MV rates. Targeted interventions may be needed during the current PMTCT Option B+ (lifelong ART to pregnant and lactating women at HIV diagnosis) to circumvent these risk factors and reduce missed visits during HIV-care.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4340-5) contains supplementary material, which is available to authorized users.

Uptake of care and treatment amongst a national cohort of HIV positive infants diagnosed at primary care level, South Africa

BACKGROUND

Loss to follow-up after a positive infant HIV diagnosis negates the potential benefits of robust policies recommending immediate triple antiretroviral therapy initiation in HIV positive infants. Whilst the diagnosis and follow-up of HIV positive infants in urban, specialized settings is easier to institutionalize, there is little information about access to care amongst HIV positive children diagnosed at primary health care clinic level. We sought to understand the characteristics of HIV positive children diagnosed with HIV infection at primary health care level, across all provinces of South Africa, their attendance at study-specific exit interviews and their reported uptake of HIV-related care. The latter could serve as a marker of knowledge, access or disclosure.

METHODS

Secondary analysis of data gathered about HIV positive children, participating in an HIV-exposed infant national observational cohort study between October 2012 and September 2014, was undertaken. HIV infected children were identified by total nucleic acid polymerase chain reaction using standardized procedures in a nationally accredited central laboratory. Descriptive analyses were conducted on the HIV positive infant population, who were treated as a case series in this analysis. Data from interviews conducted at baseline (six-weeks post-delivery) and on study exit (the first visit following infant HIV positive diagnosis) were analysed.

RESULTS

Of the 2878 HIV exposed infants identified at 6 weeks, 1803 (62.2%), 1709, 1673, 1660, 1680 and 1794 were see at 3, 6, 9, 12, 15 and 18 months respectively. In total, 101 tested HIV positive (67 at 6 weeks, and 34 postnatally). Most (76%) HIV positive infants were born to single mothers with a mean age of 26 years and an education level above grade 7 (76%). Although only 33.7% of pregnancies were planned, 83% of mothers reported receiving antiretroviral drugs to prevent MTCT. Of the 44 mothers with a documented recent CD4 cell count, the median was 346.8 cell/mm3. Four mothers (4.0%) self-reported having had TB. Only 59 (58.4%) HIV positive infants returned for an exit interview after their HIV diagnosis; there were no statistically significant differences in baseline characteristics between HIV positive infants who returned for an exit interview and those who did not. Amongst HIV positive infants who returned for an exit interview, only two HIV positive infants (3.4%) were reportedly receiving triple antiretroviral therapy (ART). If we assume that all HIV positive children who did not return for their exit interview received ART, then ART uptake amongst these HIV positive children < 18 months would be 43.6%.

CONCLUSIONS

Early ART uptake amongst children aged 15 months and below was low. This raises questions about timely, early paediatric ART uptake amongst HIV positive children diagnosed in primary health care settings. Qualitative work is needed to understand low and delayed paediatric ART uptake in young children, and more work is needed to measure progress with infant ART initiation at primary care level since 2014.

An approach for evaluating early and long term mother-to-child transmission of HIV (MTCT) in low and middle income countries: a South African experience

BACKGROUND

Eliminating mother-to-child transmission of HIV is a global public health target. Robust, feasible methodologies to measure population level impact of programmes to prevent mother-to-child transmission of HIV (PMTCT) are needed in high HIV prevalence settings. We present a summary of the protocol of the South African PMTCT Evaluation (SAPMTCTE) with its revision over three repeated rounds of the survey, 2010-2014.

METHODS

Three cross sectional surveys (2010, 2011-2012 and 2012-2013) were conducted in 580 primary health care immunisation service points randomly selected after stratified multistage probability proportional to size sampling. All infants aged 4-8 weeks receiving their six-week immunisation at a sampled facility on the day of the visit were eligible to participate. Trained research nurses conducted interviews and took infant dried blood spot (iDBS) samples for HIV enzyme immunoassay (EIA) and total nucleic acid polymerase chain reaction (PCR) testing. Interviews were conducted using mobile phones and iDBS were sent to the National Health Laboratory for testing. All findings were adjusted for study design, non-response, and weighted for number of South African live-birth in each study round. In 2012 a national closed cohort of these 4 to 8-week old infants testing EIA positive (HIV Exposed Infants) from the 2012-2013 cross-sectional survey was established to estimate longer-term PMTCT impact to 18 months. Follow-up analyses were to estimate weighted cumulative MTCT until 18 months, postnatal MTCT from 6 weeks until 18 months and a combined outcome of MTCT-or-death, using a competing risks model, with death as a competing risk. HIV-free survival was defined as a child surviving and HIV-negative up to 18 months or last visit seen. A weighted cumulative incidence analysis was conducted, adjusting for survey design effects.

DISCUSSION

In the absence of robust high-quality routine medical recording systems, in the context of a generalised HIV epidemic, national surveys can be used to monitor PMTCT effectiveness; however, monitoring long-term outcomes nationally is difficult due to poor retention in care.

Adolescent Access to Care and Risk of Early Mother-to-Child HIV Transmission

PURPOSE

Adolescent females aged 15-19 account for 62% of new HIV infections and give birth to 16 million infants annually. We quantify the risk of early mother-to-child transmission (MTCT) of HIV among adolescents enrolled in nationally representative MTCT surveillance studies in South Africa.

METHODS

Data from 4,814 adolescent (≤19 years) and 25,453 adult (≥20 years) mothers and their infants aged 4-8 weeks were analyzed. These data were gathered during three nationally representative, cross-sectional, facility-based surveys, conducted in 2010, 2011-2012, and 2012-2013. All infants were tested for HIV antibody (enzyme immunoassay), to determine HIV exposure. Enzyme immunoassay-positive infants or those born to self-reported HIV-positive mothers were tested for HIV infection (total nucleic acid polymerase chain reaction). Maternal HIV positivity was inferred from infant HIV antibody positivity. All analyses were weighted for sample realization and population live births.

RESULTS

Adolescent mothers, compared with adult mothers, have almost three times less planned pregnancies 14.4% (95% confidence interval [CI]: 12.5-16.5) versus 43.9% (95% CI: 42.0-45.9) in 2010 and 15.2% (95% CI: 13.0-17.9) versus 42.8% (95% CI: 40.9-44.6) in 2012-2013 (p < .0001), less prevention of MTCT uptake (odds ratio [OR] in favor of adult mothers = 3.36, 95% CI: 2.95-3.83), and higher early MTCT (adjusted OR = 3.0, 95% CI: 1.1-8.0), respectively. Gestational age at first antenatal care booking was the only significant predictor of early MTCT among adolescents.

CONCLUSIONS

Interventions that appeal to adolescents and initiate sexual and reproductive health care early should be tested in low- and middle-income settings to reduce differential service uptake and infant outcomes between adolescent and adult mothers.

Uptake and predictors of early postnatal follow-up care amongst mother-baby pairs in South Africa: Results from three population-based surveys, 2010-2013

Background

Achieving World Health Organization (WHO) recommendations for postnatal care (PNC) within the first few weeks of life is vital to eliminating early mother–to–child transmission of HIV (MTCT) and improving infant health. Almost half of the annual global deaths among children under five occur during the first six weeks of life. This study aims to identify uptake of three PNC visits within the first six weeks of life as recommended by WHO among South African mother–infant pairs, and factors associated with uptake.

Methods

We analyzed data from three facility–based, nationally representative surveys (2010, 2011/12 and 2012/13) primarily designed to determine the effectiveness of the South African program to prevent MTCT. This analysis describes the proportion of infants achieving the WHO recommendation of at least 3 PNC visits. Interviews from 27 699 HIV–negative and HIV–positive mothers of infants aged 4–8 weeks receiving their six week immunization were included in analysis. Data were analyzed using STATA 13.0 and weighted for sample ascertainment and South African live births. We fitted a multivariable logistic regression model to estimate factors associated with early PNC uptake.

Results

Over half (59.6%, 95% confidence interval (CI) = 59.0–60.3) of mother–infant pairs received the recommended three PNC visits during the first 6 weeks; uptake was 63.1% (95% CI = 61.9–64.3) amongst HIV exposed infants and 58.1% (95% CI = 57.3–58.9) amongst HIV unexposed infants. Uptake of early PNC improved significantly with each survey, but varied significantly by province. Multivariable analysis of the pooled data, controlling for survey year, demonstrated that number of antenatal visits (4+ vs <4 Adjusted odds ratio (aOR) = 1.13, 95% CI = 1.04–1.23), timing of initial antenatal visits (≤12 weeks vs >12 weeks, aOR = 1.13, 95% CI = 1.04–1.23), place of delivery (clinic vs hospital aOR = 1.5, 1.3–1.6), and infant HIV exposure (exposed vs unexposed aOR = 1.2, 95% CI = 1.1–1.2) were the key factors associated with receiving recommended PNC visits.

Conclusions

Approximately 40% of neonates did not receive three or more postnatal care visits in the first 6 weeks of life from 2010–2013. To improve uptake of early PNC, early antenatal booking, more frequent antenatal care attendance, and attention to HIV negative women is needed.

Enhanced sensitivity and responses to viologens from a whole-cell bacterial bioreporter treated with branched polyethyleneimines

AIMS

Evaluate the use of polyethyleneimines (PEIs) as membrane permeabilizers to improve the responses and sensitivity of a bacterial bioreporter strain to viologens.

METHODS AND RESULTS

The responses from E. coli str. EBS, i.e., E. coli BW25113 carrying plasmid pSDS, when exposed to five different viologens were characterized, as were the toxicities of seven different PEIS, including two linear and five branched species. Based on these results, benzyl viologen led to the greatest responses, and 0·8-kDa branched PEI (BPEI) was the least toxic of the PEIs tested and, therefore, both were selected for the subsequent tests. The bioluminescence and relative responses from E. coli str. EBS exposed to various concentrations of 0·8 kDa BPEI identified 400 mg l^-1 as the optimal concentration. Using this concentration, tests were performed with all five of the viologens.

CONCLUSIONS

The responses from E. coli str. EBS to the viologens were improved, with the maximum relative bioluminescence values increasing between 5·6 and 16·5-fold. The minimum detectable levels for four of the viologens were likewise improved 2- to 4-fold.

SIGNIFICANCE AND IMPACT OF STUDY

Improving bacterial membrane permeability in a controlled manner using BPEIs can improve biosensing of toxic compounds, as well as be used in biofuel and bioenergy applications where membrane permeability to a solute is important.

Structural Level Differences in the Mother-to-Child HIV Transmission Rate in South Africa: A Multilevel Assessment of Individual-, Health Facility-, and Provincial-Level Predictors of Infant HIV Transmission

OBJECTIVES

In 2010, South Africa reported an early mother-to-child transmission (MTCT) rate of 3.5% at 4-8 weeks postpartum. Provincial early MTCT rates ranged from 1.4% [95% confidence interval (CI): 0.1 to 3.4] to 5.9% (95% CI: 3.8 to 8.0). We sought to determine reasons for these geographic differences in MTCT rates.

METHODS

This study used multilevel modeling using 2010 South African prevention of mother-to-child transmission (PMTCT) evaluation (SAPMTCTE) data from 530 facilities. Interview data and blood samples of infants were collected from 3085 mother-infant pairs at 4-8 weeks postpartum. Facility-level data on human resources, referral systems, linkages to care, and record keeping were collected through facility staff interviews. Provincial level data were gathered from publicly available data (eg, health professionals per 10,000 population) or aggregated at province-level from the SAPMTCTE (PMTCT maternal-infant antiretroviral (ARV) coverage). Variance partition coefficients and odds ratios (for provincial facility- and individual-level factors influencing MTCT) from multilevel modeling are reported.

RESULTS

The provincial- (5.0%) and facility-level (1.4%) variance partition coefficients showed no substantive geographic variation in early MTCT. In multivariable analysis accounting for the multilevel nature of the data, the following were associated with early MTCT: individual-level-low maternal-infant ARV uptake [adjusted odds ratio (AOR) = 2.5, 95% CI: 1.7 to 3.5], mixed breastfeeding (AOR = 1.9, 95% CI: 1.3 to 2.9) and maternal age <20 years (AOR 1.8, 95% CI: 1.1 to 3.0); facility-level-insufficient (≤2) health care-personnel for HIV-testing services (AOR = 1.8, 95% CI: 1.1 to 3.0); provincial-level PMTCT ARV (maternal-infant) coverage lower than 80% (AOR = 1.4, 95% CI: 1.1 to 1.9), and number of health professionals per 10,000 population (AOR = 0.99, 95% CI: 0.98 to 0.99).

CONCLUSIONS

There was no substantial province-/facility-level MTCT difference. This could be due to good overall performance in reducing early MTCT. Disparities in human resource allocation (including allocation of insufficient health care personnel for testing and care at facility level) and PMTCT coverage influenced overall PMTCT programme performance. These are long-standing systemic problems that impact quality of care.

Population-level effectiveness of PMTCT Option A on early mother-to-child (MTCT) transmission of HIV in South Africa: implications for eliminating MTCT

Background

Eliminating mother–to–child transmission of HIV (EMTCT), defined as ≤50 infant HIV infections per 100 000 live births, is a global priority. Since 2011 policies to prevent mother–to–child transmission of HIV (PMTCT) shifted from maternal antiretroviral (ARV) treatment or prophylaxis contingent on CD4 cell count to lifelong maternal ARV treatment (cART). We sought to measure progress with early (4–8 weeks postpartum) MTCT prevention and elimination, 2011–2013, at national and sub–national levels in South Africa, a high antenatal HIV prevalence setting ( ≈ 29%), where early MTCT was 3.5% in 2010.

Methods

Two surveys were conducted (August 2011–March 2012 and October 2012–May 2013), in 580 health facilities, randomly selected after two–stage probability proportional to size sampling of facilities (the primary sampling unit), to provide valid national and sub–national–(provincial)–level estimates. Data collectors interviewed caregivers of eligible infants, reviewed patient–held charts, and collected infant dried blood spots (iDBS). Confirmed positive HIV enzyme immunoassay (EIA) and positive total HIV nucleic acid polymerase chain reaction (PCR) indicated infant HIV exposure or infection, respectively. Weighted survey analysis was conducted for each survey and for the pooled data.

Findings

National data from 10 106 and 9120 participants were analyzed (2011–12 and 2012–13 surveys respectively). Infant HIV exposure was 32.2% (95% confidence interval (CI) 30.7–33.6%), in 2011–12 and 33.1% (95% CI 31.8–34.4%), provincial range of 22.1–43.6% in 2012–13. MTCT was 2.7% (95% CI 2.1%–3.2%) in 2011–12 and 2.6% (95% CI 2.0–3.2%), provincial range of 1.9–5.4% in 2012–13. HIV–infected ARV–exposed mothers had significantly lower unadjusted early MTCT (2.0% [2011–12: 1.6–2.5%; 2012–13:1.5–2.6%]) compared to HIV–infected ARV–naive mothers [10.2% in 2011–12 (6.5–13.8%); 9.2% in 2012–13 (5.6–12.7%)]. Pooled analyses demonstrated significantly lower early MTCT among exclusive breastfeeding (EBF) mothers receiving >10 weeks ARV prophylaxis or cART compared with EBF and no ARVs: (2.2% [95% CI 1.25–3.09%] vs 12.2% [95% CI 4.7–19.6%], respectively); among HIV–infected ARV–exposed mothers, 24.9% (95% CI 23.5–26.3%) initiated cART during or before the first trimester, and their early MTCT was 1.2% (95% CI 0.6–1.7%). Extrapolating these data, assuming 32% EIA positivity and 2.6% or 1.2% MTCT, 832 and 384 infants per 100 000 live births were HIV infected, respectively.

Conclusions

Although we demonstrate sustained national–level PMTCT impact in a high HIV prevalence setting, results are far–removed from EMTCT targets. Reducing maternal HIV prevalence and treating all maternal HIV infection early are critical for further progress.

Missed Opportunities along the Prevention of Mother-to-Child Transmission Services Cascade in South Africa: Uptake, Determinants, and Attributable Risk (the SAPMTCTE)

Objectives

We examined uptake of prevention of mother-to-child HIV transmission (PMTCT) services, predictors of missed opportunities, and infant HIV transmission attributable to missed opportunities along the PMTCT cascade across South Africa.

Methods

A cross-sectional survey was conducted among 4–8 week old infants receiving first immunisations in 580 nationally representative public health facilities in 2010. This included maternal interviews and testing infants’ dried blood spots for HIV. A weighted analysis was performed to assess uptake of antenatal and perinatal PMTCT services along the PMTCT cascade (namely: maternal HIV testing, CD4 count test/result, and receiving maternal and infant antiretroviral treatment) and predictors of dropout. The population attributable fraction associated with dropouts at each service point are estimated.

Results

Of 9,803 mothers included, 31.7% were HIV-positive as identified by reactive infant antibody tests. Of these 80.4% received some form of maternal and infant antiretroviral treatment. More than a third (34.9%) of mothers dropped out from one or more steps in the PMTCT service cascade. In a multivariable analysis, the following characteristics were associated with increased dropout from the PMTCT cascade: adolescent (<20 years) mothers, low socioeconomic score, low education level, primiparous mothers, delayed first antenatal visit, homebirth, and non-disclosure of HIV status. Adolescent mothers were twice (adjusted odds ratio: 2.2, 95% confidence interval: 1.5–3.3) as likely to be unaware of their HIV-positive status and had a significantly higher rate (85.2%) of unplanned pregnancies compared to adults aged ≥20 years (55.5%, p = 0.0001). A third (33.8%) of infant HIV infections were attributable to dropout in one or more steps in the cascade.

Conclusion

A third of transmissions attributable to missed opportunities of PMTCT services can be prevented by optimizing the uptake of PMTCT services. Identified risk factors for low PMTCT service uptake should be addressed through health facility and community-level interventions, including raising awareness, promoting women education, adolescent focused interventions, and strengthening linkages/referral-system between communities and health facilities.

Impact of Maternal HIV Seroconversion during Pregnancy on Early Mother to Child Transmission of HIV (MTCT) Measured at 4-8 Weeks Postpartum in South Africa 2011-2012: A National Population-Based Evaluation

BACKGROUND

Mother-to-child transmission of HIV (MTCT) depends on the timing of HIV infection. We estimated HIV-seroconversion during pregnancy (HSP) after having a HIV-negative result antenatally, and its contribution to early MTCT in South Africa (SA).

METHODS AND FINDINGS

Between August 2011 and March 2012, we recruited a nationally representative sample of mother-infant pairs with infants aged 4-to-8 weeks from 578 health facilities. Data collection included mother interviews, child health-card reviews, and infant dried-blood-spots sample (iDBS). iDBS were tested for HIV antibodies and HIV-deoxyribonucleic-acid (HIV-DNA). HSP was defined as maternal self-report of an HIV-negative test during this pregnancy, no documented use of antiretroviral drugs and a matched HIV sero-positive iDBS. We used 20 imputations from a uniform distribution for time from reported antenatal HIV-negative result to delivery to estimate time of HSP. Early MTCT was defined based on detection of HIV-DNA in iDBS. Estimates were adjusted for clustering, nonresponse, and weighted by SA's 2011 live-births.

RESULTS

Of 9802 mother-infant pairs, 2738 iDBS were HIV sero-positive, including 212 HSP, resulting in a nationally weighted estimate of 3.3% HSP (95% Confidence Interval: 2.8%-3.8%). Median time of HIV-seroconversion was 32.8weeks gestation;28.3% (19.7%- 36.9%) estimated to be >36 weeks. Early MTCT was 10.7% for HSP (6.2%-16.8%) vs. 2.2% (1.7%-2.8%) for mothers with known HIV-positive status. Although they represent 2.2% of all mothers and 6.7% of HIV-infected mothers, HSP accounted for 26% of early MTCT. Multivariable analysis indicated the highest risk for HSP was among women who knew the baby's father was HIV-infected (adjusted-hazard ratio (aHR) 4.71; 1.49-14.99), or who had been screened for tuberculosis (aHR 1.82; 1.43-2.32).

CONCLUSIONS

HSP risk is high and contributes significantly to early MTCT. Identification of HSP by repeat-testing at 32 weeks gestation, during labor, 6 weeks postpartum, in tuberculosis-exposed women, and in discordant couples might reduce MTCT.

Missed opportunities for early infant HIV diagnosis: results of a national study in South Africa

BACKGROUND

Services to diagnose early infant HIV infection should be offered at the 6-week immunization visit. Despite high 6-week immunization attendance, the coverage of early infant diagnosis (EID) is low in many sub-Saharan countries. We explored reasons for such missed opportunities at 6-week immunization visits.

METHODS

We used data from 2 cross-sectional surveys conducted in 2010 in South Africa. A national assessment was undertaken among randomly selected public facilities (n = 625) to ascertain procedures for EID. A subsample of these facilities (n = 565) was revisited to assess the HIV status of 4- to 8-week-old infants receiving 6-week immunization. We examined potential missed opportunities for EID. We used logistic regression to assess factors influencing maternal intention to report for EID at 6-week immunization visits.

RESULTS

EID services were available in >95% of facilities and 72% of immunization service points (ISPs). The majority (68%) of ISPs provide EID for infants with reported or documented (on infant's Road-to-Health Chart/booklet-iRtHC) HIV exposure. Only 9% of ISPs offered provider-initiated counseling and testing for infants of undocumented/unknown HIV exposure. Interviews with self-reported HIV-positive mothers at ISPs revealed that only 55% had their HIV status documented on their iRtHC and 35% intended to request EID during 6-week immunization. Maternal nonreporting for EID was associated with fear of discrimination, poor adherence to antiretrovirals, and inadequate knowledge about mother-to-child HIV transmission.

CONCLUSIONS

Missed opportunities for EID were attributed to poor documentation of HIV status on iRtHC, inadequate maternal knowledge about mother-to-child HIV transmission, fear of discrimination, and the lack of provider-initiated counseling and testing service for undocumented, unknown, or undeclared HIV-exposed infants.

First population-level effectiveness evaluation of a national programme to prevent HIV transmission from mother to child, South Africa

Background

There is a paucity of data on the national population-level effectiveness of preventing mother-to-child transmission (PMTCT) programmes in high-HIV-prevalence, resource-limited settings. We assessed national PMTCT impact in South Africa (SA), 2010.

Methods

A facility-based survey was conducted using a stratified multistage, cluster sampling design. A nationally representative sample of 10 178 infants aged 4–8 weeks was recruited from 565 clinics. Data collection included caregiver interviews, record reviews and infant dried blood spots to identify HIV-exposed infants (HEI) and HIV-infected infants. During analysis, self-reported antiretroviral (ARV) use was categorised: 1a: triple ARV treatment; 1b: azidothymidine >10 weeks; 2a: azidothymidine ≤10 weeks; 2b: incomplete ARV prophylaxis; 3a: no antenatal ARV and 3b: missing ARV information. Findings were adjusted for non-response, survey design and weighted for live-birth distributions.

Results

Nationally, 32% of live infants were HEI; early mother-to-child transmission (MTCT) was 3.5% (95% CI 2.9% to 4.1%). In total 29.4% HEI were born to mothers on triple ARV treatment (category 1a) 55.6% on prophylaxis (1b, 2a, 2b), 9.5% received no antenatal ARV (3a) and 5.5% had missing ARV information (3b). Controlling for other factors groups, 1b and 2a had similar MTCT to 1a (Ref; adjusted OR (AOR) for 1b, 0.98, 0.52 to 1.83; and 2a, 1.31, 0.69 to 2.48). MTCT was higher in group 2b (AOR 3.68, 1.69 to 7.97). Within group 3a, early MTCT was highest among breastfeeding mothers 11.50% (4.67% to 18.33%) for exclusive breast feeding, 11.90% (7.45% to 16.35%) for mixed breast feeding, and 3.45% (0.53% to 6.35%) for no breast feeding). Antiretroviral therapy or >10 weeks prophylaxis negated this difference (MTCT 3.94%, 1.98% to 5.90%; 2.07%, 0.55% to 3.60% and 2.11%, 1.28% to 2.95%, respectively).

Conclusions

SA, a high-HIV-prevalence middle income country achieved <5% MTCT by 4–8 weeks post partum. The long-term impact on PMTCT on HIV-free survival needs urgent assessment.

Integration of prevention of mother-to-child transmission of HIV (PMTCT) postpartum services with other HIV care and treatment services within the maternal and child health setting in Zimbabwe, 2012

Background

We assessed the integration of PMTCT services during the postpartum period including early infant diagnosis of HIV (EID) and adult and pediatric antiretroviral therapy (ART) in maternal and child health (MCH) facilities in Zimbabwe

Methods and Findings

From August to December 2012 we conducted a cross-sectional survey of a nationally representative sample of 151 MCH facilities. A questionnaire was used to survey each site about staff training, dried blood spot sample (DBS) collection, turnaround time (TAT) for test results, PMTCT services, and HIV care and treatment linkages for HIV-infected mothers and children and HIV-exposed infants. Descriptive analyses were used.

Of the facilities surveyed, all facilities were trained on DBS collection and 92% responded. Approximately, 99% of responding facilities reported providing DBS collection and a basic HIV-exposed infant service package including EID, extended nevirapine prophylaxis, and use of cotrimoxazole. DBS collection was integrated with immunisations at 83% of facilities, CD4 testing with point-of-care machines was available at 37% of facilities, and ART for both mothers and children was provided at 27% of facilities. More than 80% of facilities reported that DBS test results take >4 weeks to return; TAT did not have a direct association with any specific type of transport, distance to the lab, or intermediate stops for data to travel.

Conclusions

Zimbabwe has successfully scaled up and integrated the national EID and PMTCT programs into the existing MCH setting. The long TAT of infant DBS test results and the lack of integrated ART programs in the MCH setting could reduce effectiveness of the national PMTCT and ART programs. Addressing these important gaps will support successful implementation of the 2014 Zimbabwe's PMTCT guidelines under which all HIV-infected pregnant and breastfeeding women will be offered life-long ART and decentralized ART care.

Development of solar concentrators for high-power solar-pumped lasers

We have developed unique solar concentrators for solar-pumped solid-state lasers to improve both efficiency and laser output power. Natural sunlight is collected by a primary concentrator which is a 2  m×2  m Fresnel lens, and confined by a cone-shaped hybrid concentrator. Such solar power is coupled to a laser rod by a cylinder with coolant surrounding it that is called a liquid light-guide lens (LLGL). Performance of the cylindrical LLGL has been characterized analytically and experimentally. Since a 14 mm diameter LLGL generates efficient and uniform pumping along a Nd:YAG rod that is 6 mm in diameter and 100 mm in length, 120 W cw laser output is achieved with beam quality factor M2 of 137 and overall slope efficiency of 4.3%. The collection efficiency is 30.0  W/m2, which is 1.5 times larger than the previous record. The overall conversion efficiency is more than 3.2%, which can be comparable to a commercial lamp-pumped solid-state laser. The concept of the light-guide lens can be applied for concentrator photovoltaics or other solar energy optics.

120 watt continuous wave solar-pumped laser with a liquid light-guide lens and an Nd:YAG rod

We propose a simple and efficient pumping approach for a high-power solar-pumped laser by using a liquid light-guide lens (LLGL) and a hybrid pumping cavity. A 2×2 m Fresnel lens is used as a primary concentrator to collect natural sunlight; 120 W cw laser power and a 4.3% total slope efficiency are achieved with a 6-mm diameter Nd:YAG rod within a 14-mm diameter LLGL. The corresponded collection efficiency is 30.0 W/m(2), which is 1.5 times larger than the previous record. This result is unexpectedly better than that of Cr:Nd:YAG ceramics. It is because the scattering coefficient of Cr:Nd:YAG ceramics is 0.004cm(1), which is 2 times larger than that of the Nd:YAG crystal, although both have similar saturation gains.

Nosocomial outbreak of novel arenavirus infection, southern Africa

This case reinforces the need for strict screening of internationally transferred patients.

A nosocomial outbreak of disease involving 5 patients, 4 of whom died, occurred in South Africa during September–October 2008. The first patient had been transferred from Zambia to South Africa for medical management. Three cases involved secondary spread of infection from the first patient, and 1 was a tertiary infection. A novel arenavirus was identified. The source of the first patient’s infection remains undetermined.

Preventing mother-to-child transmission of HIV in Vietnam: an assessment of progress and future directions

Preliminary to the development a new program supporting perinatal HIV prevention, this assessment was conducted to evaluate Vietnam's national prevention of mother-to-child HIV transmission (PMTCT) program by estimating HIV prevalence among prenatal women and analyzing the healthcare system capacity to deliver services. In 2002-03, a technical team reviewed existing national and local surveillance and program data and conducted on-site interviews and observations at maternal-child health (MCH) programs in the seven provinces with highest HIV rates. The team found that despite high (85%) prenatal service utilization and widespread availability of HIV testing and dissemination of prevention protocols, few HIV-infected mothers were identified in time to allow effective perinatal HIV prevention. Program deficits clustered around the general areas of provider misunderstanding of occupational HIV risk and MTCT, impractical PMTCT policies, and practices hampering effective use of prevention and treatment protocols. Existing problems were significant but modifiable, and will require implementation of practical and appropriate guidelines, enhanced clinical and laboratory capacity, and continued program management and monitoring.

Factors associated with declining HIV testing and failure to return for results among pregnant women in Vietnam

In a cross-sectional study, 53.2% of 500 antenatal attendees at Hai-Phong Hospital accepted HIV testing and 55.3% returned for results. Factors associated with declining included opinions about providing testing or that only high-risk pregnant women need testing, intention to decline testing, being a housewife, perception of poor healthcare support, and worry about husband's disapproval. Low educational level was associated with not returning for results. Testing programmes need to address husbands' attitudes, low education levels, and perceptions of risk.

Molecular determinants of apoptosis induced by the cytotoxic ribonuclease onconase: evidence for cytotoxic mechanisms different from inhibition of protein synthesis

Cytotoxic endoribonucleases (RNases) possess a potential for use in cancer therapy. However, the molecular determinants of RNase-induced cell death are not well understood. In this work, we identify such determinants of the cytotoxicity induced by onconase, an amphibian cytotoxic RNase. Onconase displayed a remarkable specificity for tRNA in vivo, leaving rRNA and mRNA apparently undamaged. Onconase-treated cells displayed apoptosis-associated cell blebbing, nuclear pyknosis and fragmentation (karyorrhexis), DNA fragmentation, and activation of caspase-3-like activity. The cytotoxic action of onconase correlated with inhibition of protein synthesis; however, we present evidence for the existence of a mechanism of onconase-induced apoptosis that is independent of inhibition of protein synthesis. The caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(OMe) fluoromethyl ketone (zVADfmk), at concentrations that completely prevent apoptosis and caspase activation induced by ligation of the death receptor Fas, had only a partial protective effect on onconase-induced cell death. The proapoptotic activity of the p53 tumor suppressor protein and the Fas ligand/Fas/Fas-associating protein with death domain (FADD)/caspase-8 proapoptotic cascade were not required for onconase-induced apoptosis. Procaspases-9, -3, and -7 were processed in onconase-treated cells, suggesting the involvement of the mitochondrial apoptotic machinery in onconase-induced apoptosis. However, the onconase-induced activation of the caspase-9/caspase-3 cascade correlated with atypically little release of cytochrome c from mitochondria. In turn, the low levels of cytochrome c released from mitochondria correlated with a lack of detectable translocation of proapoptotic Bax from the cytosol onto mitochondria in response to onconase. This suggests the possibility of involvement of a different, potentially Bax- and cytochrome c-independent mechanism of caspase-9 activation in onconase-treated cells. As one possible mechanism, we demonstrate that procaspase-9 is released from mitochondria in onconase-treated cells. A detailed understanding of the molecular determinants of the cytotoxic action of onconase could provide means of positive or negative therapeutic modulation of the activity of this potent anticancer agent.

Ultraviolet radiation triggers the ribotoxic stress response in mammalian cells

The ribotoxic stress response, which is conserved between prokaryotes and eukaryotes, is a cellular reaction to cytotoxic interference with the function of the 3'-end of the large (23 S/28 S) ribosomal RNA. The 3'-end of the large rRNA is directly involved in the three sequential steps of translational elongation: the aminoacyl-tRNA binding, the peptidyl transfer, and the ribosomal translocation. In mammalian cells, the ribotoxic stress response involves activation of the stress-activated protein kinase/c-Jun NH2-terminal kinase and the p38 mitogen-activated protein kinase and transcriptional induction of immediate early genes such as c-fos and c-jun. Active ribosomes are essential mediators of the ribotoxic stress response. We demonstrate here that the transcriptional response of mammalian cells to ultraviolet radiation (UV response) displays the characteristics of a ribotoxic stress response, inasmuch as (i) the activation of stress kinases and gene expression in response to UV requires the presence of active ribosomes at the moment of irradiation; (ii) UV irradiation inhibits protein synthesis; and (iii) irradiation of cells with UV causes specific damage to the 3'-end of the 28 S rRNA. In contrast, the activation of the stress kinases by hyperosmolarity, by the DNA-cross-linking agent diepoxybutane, or by growth factors and cytokines does not depend on the presence of active ribosomes. Our results identify UV as a potential ribotoxic stressor and support the notion that some of the cellular signaling cascades in response to UV might be generated in the ribosome, possibly triggered by damage to rRNA.

[Everything is relative...about the Hanoi Institute of Traditional Medicine]

At the Symposium entitled "Health, Culture, and Quality of Life" held in Hanoi in 1993, the authors of this report met the physicians in charge of the Traditional Medicine Institute of Hanoi which works with the World Health Organization for traditional medicine. After an historical overview of the foundation of this center providing research, care, and training under the auspices of the Hanoi School of Medicine, Professor Hoang Bao Chau described a practice based on revision of ancestral traditions in accordance with scientific methods, the resulting synthesis being up-to-date yet in keeping with heritage. This novel and pragmatic approach, which takes into account the complexity of man, offers an opportunity to reflect on the current status of medical practices in the world and on their adaptation to each population at a time when the experience of the Other seems almost impossible to communicate.

Ribotoxic stress response: activation of the stress-activated protein kinase JNK1 by inhibitors of the peptidyl transferase reaction and by sequence-specific RNA damage to the alpha-sarcin/ricin loop in the 28S rRNA

Inhibition of protein synthesis per se does not potentiate the stress-activated protein kinases (SAPKs; also known as cJun NH2-terminal kinases [JNKs]). The protein synthesis inhibitor anisomycin, however, is a potent activator of SAPKs/JNKs. The mechanism of this activation is unknown. We provide evidence that in order to activate SAPK/JNK1, anisomycin requires ribosomes that are translationally active at the time of contact with the drug, suggesting a ribosomal origin of the anisomycin-induced signaling to SAPK/JNK1. In support of this notion, we have found that aminohexose pyrimidine nucleoside antibiotics, which bind to the same region in the 28S rRNA that is the target site for anisomycin, are also potent activators of SAPK/JNK1. Binding of an antibiotic to the 28S rRNA interferes with the functioning of the molecule by altering the structural interactions of critical regions. We hypothesized, therefore, that such alterations in the 28S rRNA may act as recognition signals to activate SAPK/JNK1. To test this hypothesis, we made use of two ribotoxic enzymes, ricin A chain and alpha-sarcin, both of which catalyze sequence-specific RNA damage in the 28S rRNA. Consistent with our hypothesis, ricin A chain and alpha-sarcin were strong agonists of SAPK/JNK1 and of its activator SEK1/MKK4 and induced the expression of the immediate-early genes c-fos and c-jun. As in the case of anisomycin, ribosomes that were active at the time of exposure to ricin A chain or alpha-sarcin were able to initiate signal transduction from the damaged 28S rRNA to SAPK/JNK1 while inactive ribosomes were not.

1H- and 31P-NMR studies of ditercalinium binding to a d(GCGC)2 and d(CCTATAGG)2 minihelices: a sequence specificity study

The structures of the complexes formed in aqueous solution between ditercalinium, a bis-intercalating drug, and both the self-complementary tetranucleotide d(GCGC)2 and octanucleotide d(CCTATAGG)2, have been investigated by 400-MHz 1H-nmr and 162-MHz 31P-nmr. All the nonexchangeable protons, as well as the exchangeable imino protons and the phosphorus signals, have been assigned. Both oligonucleotides have been shown to adopt a right-handed B-DNA type structure. The addition of ditercalinium to the oligonucleotides lead to the formation of complexes in slow exchange at the nmr time scale with the free helices. At all drug-to-helix ratios studied, the ditercalinium was found in the bound form, whereas free and complexed oligonucleotides were in slow exchange, allowing resonance assignments through two-dimensional chemical exchange experiments. for d(GCGC)2 the strong upfield shifts induced on all aromatic protons of both the bases and the drug by complexation with ditercalinium suggest an interaction by intercalation of the two rings. However, the loss of twofold symmetry upon binding, as well as the chemical shift variation of the drug proton signals of one of the chromophores with temperature and concentration, favor a model in which the drug-nucleotide complexes have one ring of the drug intercalated and the other stacked on top of the external base pair. The intermolecular contacts between drug protons and nucleotide protons give a defined geometry for complexation that is consistent with the proposed model. In contrast, with d(CCTATAGG)2 several drug-nucleotide complexes were formed and a large increase in line broadening was observed at high drug-to-DNA ratios, precluding a detailed analysis of these complexes. However, the large upfield shift in the imino proton resonances together with the shielding of the ditercalinium ring protons favor a model with bis-intercalation of ditercalinium. This model is supported by the downfield shift of at least 4 out of 14 phosphorus signals. The results are compared with those obtained on ditercalinium binding to the homologous sequences d(CGCG)2 and d(TTCGCGAA)2, and discussed in terms of sequence specificity.

1H-NMR studies of a monointercalating drug into a d(CpGpApTpCpG)2 minihelix

The structure of the complex formed between the 7H-pyridocarbazole monomer [[(2-piperidyl)-2,1-ethane-yl] [10-methoxy-7H-pyrido[4,3-c]carbazolium] dimethane sulfonate] and the autocomplementary hexanucleotide d(CpGpApTpCpG)2 in aqueous solution is analyzed by 270- and 400-MHz 1H-nmr. The large upfield shifts observed for both the drug and the self-complementary hexanucleotide protons provide evidence for intercalated complexes. The observation of intermolecular nuclear Overhauser effects between drug and the hexanucleotide protons gives a privileged orientation of the drug in the intercalation site with the quaternarizing ethyl piperidine chain protruding in the major groove. Moreover, the data suggest an intercalation based on the neighbor exclusion site principle in the three alternating sequences.

Bisintercalation of ditercalinium into a d(CpGpApTpCpG)2 minihelix: a 1H- and 31P-NMR study

The structure of the complex formed in aqueous solution between ditercalinium, a bisintercalating drug, and the self-complementary hexanucleotide d(CpGpApTpCpG)2 is investigated by 400-MHz 1H-nmr and 162-MHz 31P-nmr. Whatever the drug to helix ratio, ditercalinium occurred in the bound form, whereas free and complexed hexanucleotide are in slow exchange. This allows unambiguous resonance assignment through two-dimensional chemical exchange experiments. The strong upfield shifts measured on most aromatic protons on both drug and bases as well as on DNA imino protons are consistent with bisintercalation of the dimer. Nuclear Overhauser effects observed between drug and nucleotide protons give a defined geometry for complexation, and suggest a DNA conformational change upon drug binding.

Independent transcriptional regulation of a single VL30 element by epidermal growth factor and activators of protein kinase C

A single VL30 element present in the RVL-3 cell line was transcriptionally induced by both epidermal growth factor (EGF) and the protein kinase C (pkC) activators 12-O-tetradecanoylphorbol-13-acetate (TPA) and sn-1,2-dioctanoylglycerol within 5 min of stimulation. Following TPA-induced depletion of protein kinase C activity, EGF stimulation of VL30 transcription and accumulation was unaffected while TPA effects were inhibited, implying that EGF and TPA act by separable pathways.

Processing of complex heteroduplexes in Escherichia coli and Cos-1 monkey cells

Upon transformation into Escherichia coli or Cos-1 monkey cells, heteroduplex DNA made of two sequences containing many nucleotide mismatches yields a wide array of different molecules, some with a patchwork structure. Thus, complex heteroduplexes can be processed to generate many genetic variants.

2-l-Rhamnopyranosyl[1,2,4]triazolo[1,5-a]pyridine. 4' and 3' Oxidation products. Synthesis and structure-activity relationships

A series of 2-alpha-L-rhamnopyranosylnitro[1,2,4]triazolo[1,5-a] pyridine C-nucleosides was synthesized from the condensation oa thioiminoether with nitro-2-pyridylhydrazines. Catalytic reduction afforded the corresponding amino derivative. A 1',2' unsaturated C-nucleoside was also obtained by two different routes. Selective oxidation gave the 3'- and 4'-ketonucleosides. The cytotoxic properties of the nucleosides, as well as their effect on viral transformation and replication, were described. The nitro derivatives inhibit viral replication, but at toxic doses; the introduction of a keto function leads to a product which inhibits the replication of murine leukemia virus (MuLV) at noncytotoxic concentrations. The amino derivatives have no significant antiviral effect.