Population-level risk factors for vertical transmission of HIV in the national prevention of mother-to-child transmission programme in South Africa: An ecological analysis.

BACKGROUND: Although South Africa has an overall mother-to-child transmission (MTCT) of HIV rate <5%, case rates remain high. OBJECTIVES: To identify population-level predictors of MTCT to inform targeted interventions to further reduce paediatric HIV incidence. METHODS: The study was an ecological analysis of routine laboratory HIV-related test data from a synthetic cohort of women of reproductive age living with HIV (WRLHIV), identified from the National Health Laboratory Service's Corporate Data Warehouse between 2016 and 2017. Criteria based on syphilis screening and timing of HIV-related tests were used to identify pregnant and non-pregnant WRLHIV. Pregnant WRLHIV were followed from cohort entry at the first antenatal care (fANC) visit, through delivery to exit at the latest viral load (VL) or 15 months post delivery. Follow-up for non-pregnant WRLHIV started at cohort entry on 1 January 2016 to exit at the latest VL or 31 December 2018. HIV VL tests performed at cohort entry, delivery and cohort exit described viraemia (VL ≥50 copies/mL) at subdistrict level. A negative binomial regression model determined the association between MTCT cases and the number of viraemic WRLHIV at different time points, controlling for number of WRLHIV aged <25 years at cohort entry and other routine HIV-related indicators at subdistrict level. RESULTS: Of 3 386 507 WRLHIV identified, 178 319 (5.3%) met criteria for pregnancy. Median (interquartile range (IQR)) proportions of women with fANC booking <20 weeks' gestation, maternal HIV seroprevalence during antenatal care (ANC) and antiretroviral therapy (ART) coverage during ANC were 68.2% (62.9 - 72.8), 31.5% (23.4 - 35.7) and 94.8% (89.7 - 97.8), respectively. Viraemia was consistently higher in pregnant v. non-pregnant WRLHIV at median proportions of 42.9% (38.3 - 59.3) v. 35.0% (25.9 - 49.0) at cohort entry (p<0.001) and 36.3% (25.0 - 48.4) v. 29.6% (21.0 - 42.6) at cohort exit (p<0.001). In total, 4 535 children aged <24 months tested HIV polymerase chain reaction-positive, representing a median subdistrict-level case rate of 1 372 (914 - 2 077) per 100 000 live births. Maternal viraemia postpartum, maternal HIV seroprevalence and ART coverage during ANC positively correlated with cases of MTCT, while higher proportions of women with fANC booking <20 weeks' gestation were associated with a decline in MTCT cases. CONCLUSIONS: Findings suggest that maternal viraemia postpartum, geographical areas with a higher burden of maternal HIV, women initiating ART late in pregnancy and/or incident maternal HIV during pregnancy are significant population-level predictors of MTCT in the national prevention of MTCT programme. Scale-up of HIV prevention services is required to lower maternal HIV prevalence, while expanded access to HIV testing will fast-track ART initiation among WRLHIV. Increased VL monitoring is critical to improve VL suppression rates for elimination of MTCT.

Maternal HIV viral load testing during pregnancy and postpartum care in Gauteng Province, South Africa.

BACKGROUND: Pregnant and breastfeeding women living with HIV (WLHIV) are a target population for elimination of mother-to-child transmission of HIV (eMTCT). However, there are limited data on maternal virological responses during pregnancy and the postpartum period in South Africa (SA). OBJECTIVES: To review compliance of viral load (VL) testing with national guidelines and suppression rates during pregnancy and up to 9  months postpartum among WLHIV delivering in four tertiary hospitals in Gauteng Province, SA. METHODS: All women who had a point-of-care HIV VL test using Xpert HIV-1 VL (Cepheid, USA) at delivery in four tertiary obstetric units in Gauteng between June 2018 and February 2020 were included. HIV VL tests of eligible women performed up to 9 months before and after delivery were extracted from the National Health Laboratory Service's Corporate Data Warehouse. Proportions of women delivering who had antenatal and postpartum VL tests performed and their suppression rates were determined and expressed as percentages. RESULTS: Of 4 989 eligible WLHIV (median age 31.1 years), 917 (18.4%) had a VL performed during the antenatal period; of these, 335 (36.5%) had a VL ≥50 copies/mL and 165 (18.0%) a VL ≥1 000 copies/mL. At delivery, 1 911 women (38.3%) had a VL ≥50 copies/mL and 1 028 (20.6%) a VL ≥1 000 copies/mL. Among 627 women (12.6%) with a VL test postpartum, 234 (37.3%) had a VL ≥50 copies/mL and 93 (14.8%) a VL ≥1 000 copies/mL. Overall, having a VL test performed during the antenatal period was associated with viral suppression at delivery and receiving a VL test postpartum (p<0.001). Women with a VL ≥50 copies/mL at delivery were more likely to be younger and to remain virally unsuppressed postpartum (p<0.001) compared with women with a VL <50 copies/mL. CONCLUSIONS: Fewer than 5% of WLHIV with a VL at the time of delivery received VL monitoring during the antenatal and postpartum periods in accordance with national guidelines. More than 80% of WLHIV delivering had no evidence of VL monitoring during the antenatal period, and they were more likely than women who received monitoring during the antenatal period to be virally unsuppressed at delivery and to receive no VL monitoring postpartum. Women with a high VL at delivery were likely to remain virally unsuppressed postpartum. These results emphasise the need for closer monitoring of and rapid reaction to high maternal VLs during pregnancy, at delivery and postpartum for attainment of eMTCT.

Evaluating the performance of the GeneXpert HIV-1 qualitative assay as a consecutive test for a new early infant diagnosis algorithm in South Africa.

BACKGROUND: The proportion of HIV-exposed infants and young children infected with HIV in South Africa (SA) has declined markedly over the past decade as a result of the country's comprehensive prevention of mother-to-child transmission programme. This decrease has in turn reduced the positive predictive value (PPV) of diagnostic assays, necessitating review of early infant diagnosis (EID) algorithms to ensure improved accuracy. OBJECTIVES: To evaluate the performance of the GeneXpert HIV-1 qualitative assay (Xpert EID) as a consecutive test for infants with an 'HIV-detected' polymerase chain reaction screening test at birth. METHODS: We retrospectively analysed a longitudinal cohort of HIV-exposed infants on whom birth testing was performed, using whole-blood ethylenediaminetetra-acetic acid samples, from four tertiary sites in Gauteng Province between June 2014 and December 2019. Birth samples from all infants with a Cobas AmpliPrep/Cobas TaqMan HIV-1 Qualitative Test v2.0 (CAP/CTM v2.0) HIV-detected screening test, a concurrent Xpert EID test and a subsequent confirmatory CAP/CTM v2.0 test on a separate specimen were included. Performance of the Xpert EID in predicting final HIV status was determined as proportions with 95% confidence intervals (CIs). A comparison of indeterminate CAP/CTM v2.0 results, as per National Health Laboratory Service resulting practice, with discordant CAP/CTM v2.0 v. Xpert EID results was performed. RESULTS: Of 150 infants who met the inclusion criteria, 6 (3.9%) had an Xpert EID result discordant with final HIV status: 5 (3.3%) were false negatives and 1 (0.7%) was false positive. As a consecutive test, the Xpert EID yielded a sensitivity of 96.5% (95% CI 92 - 98.9), specificity of 85.7% (95% CI 42.1 - 99.6), PPV of 99.3% (95% CI 95.7 - 99.9), negative predictive value of 54.5% (95% CI 32.5 - 74.9) and overall accuracy of 96.1% (95% CI 91.5 - 98.5). Using discordant CAP/CTM v2.0/Xpert EID results as criteria to verify indeterminate results instead of current practice would have reduced the number of indeterminate screening results by 42.1%, from 18 (12.6%) to 11 (7.2%), without increasing the false-positive rate. CONCLUSIONS: Addition of the Xpert EID as a consecutive test for specimens with an HIV-detected PCR screening result has the potential to improve the PPV and reduce the indeterminate rate, thereby reducing diagnostic challenges and time to final status, in SA's EID programme.

Quality and turnaround times of viral load monitoring under prevention of mother-to-child transmission of HIV Option B+ in six South African districts with a high antenatal HIV burden.

BACKGROUND: Barriers to monitoring maternal HIV viral load (VL) and achieving 90% viral suppression during pregnancy and breastfeeding still need to be understood in South Africa (SA). OBJECTIVES: To measure quality of VL care and turnaround times (TATs) for returning VL results to women enrolled in the prevention of mother-to-child transmission of HIV (PMTCT) programme in primary healthcare facilities. METHODS: Data were obtained from a 2018 cross-sectional evaluation of the PMTCT Option B+ programme in six SA districts with high antenatal and infant HIV prevalence. Quality of VL care was measured as the proportion of clients reporting that results were explained to them. TATs for VL results were calculated using dates abstracted from four to five randomly selected facility-based client records to report overall facility 'short TAT' (≥80% of records with TAT ≤7 days). Logistical regression and logit-based risk difference statistics were used. RESULTS: Achieving overall short TAT was uncommon. Only 50% of facilities in one rural district, zero in one urban metro district and 9 - 38% in other districts had short TAT. The significant difference between districts was influenced by the duration of keeping results in facilities after receipt from the laboratory. Expected quality of VL care received ranged between 66% and 85%. Client-related factors significantly associated with low quality of care, observed in two urban districts and one rural district, included lower education, recent initiation of antiretroviral treatment and experiencing barriers to clinic visits. Experiencing clinic visit barriers was also negatively associated with short TATs. CONCLUSIONS: We demonstrate above-average quality of care and delayed return of results to PMTCT clients. Context-specific interventions are needed to shorten TATs.

Monitoring diagnosis, retention in care and viral load suppression in children testing HIV polymerase chain reaction-positive in two districts in South Africa.

BACKGROUND: Retention in care is associated with improved virological control and survival among HIV-infected children. However, retention of children in HIV care remains a challenge. OBJECTIVES: To describe, using routine laboratory HIV test data, the retention-in-care and virological outcomes of HIV-infected children aged <18 months in two districts in South Africa. METHODS: HIV polymerase chain reaction (PCR)-positive results of children from uMkhanyakude and Tshwane districts in KwaZulu-Natal and Gauteng provinces, respectively, tested between April 2015 and May 2016, were extracted from the National Health Laboratory Service's Corporate Data Warehouse (CDW). HIV-related tests (PCR, viral load (VL), CD4+) were documented longitudinally for each child for ≥13 months after the first positive PCR result by manually searching demographics within the CDW, supplemented by an automated patient-linking algorithm. Test sets were linked if two or more demographics (surname, name, date of birth, folder number) matched exactly. Programmatic indicators assessed included age at first positive PCR test, presumed confirmatory test rates, retention in care, and VL suppression at 6 and 12 months. RESULTS: Ninety-four and 304 children tested HIV PCR-positive in uMkhanyakude and Tshwane, respectively. The median age at diagnosis was 3.6 months (interquartile range (IQR) 1.4 - 7.1) for uMkhanyakude and 2.3 months (IQR 0.1 - 6.7) for Tshwane. In uMkhanyakude, confirmed in utero infections accounted for 18.1% of transmissions (n=17), compared with 29.6% (n=90) in Tshwane. Presumed confirmatory test rates following an initial positive PCR result were 77.7% and 71.7% for uMkhanyakude and Tshwane, respectively. Within 6 months of starting antiretroviral therapy, 43 children (58.9%) were lost to follow-up in uMkhanyakude compared with 160 (73.4%) in Tshwane. Of those retained in care at 6 months with a VL measurement, 15 (60.0%) from uMkhanyakude had a VL <1 000 copies/mL, compared with 24 (48.0%) in Tshwane. For both districts, a third of all HIV PCR-positive children were retained in care at the end of follow-up, with 29 (30.9%) in uMkhanyakude and 99 (32.5%) in Tshwane. Of these, 12 (41.4%) had a VL <1 000 copies/mL in uMkhanyakude compared with 28 (28.3%) in Tshwane. CONCLUSIONS: We demonstrate the value of routine laboratory data in monitoring diagnosis, retention and VL suppression in HIV-infected children. This approach is scalable, can be reported near real-time, is relatively inexpensive to implement, and provides a tool for improving paediatric HIV services until clinical databases can assume this role.

Leveraging the Road to Health booklet as a unique patient identifier to monitor the prevention of mother-to-child transmission programme.

BACKGROUND: Currently there is no unique patient identification system in the South African public health sector. Therefore, routine laboratory data cannot effectively be de-duplicated, thereby hampering surveillance of laboratory-diagnosed diseases such as mother-to-child transmission of HIV. OBJECTIVES: To determine the uptake of Road to Health booklet (RTHB) identifiers at HIV polymerase chain reaction (PCR) birth test and describe their performance in linking follow-up test results in the early infant diagnosis programme. METHODS: Between May 2016 and May 2017, Tshwane District Clinical Services implemented a unique patient identifier pilot project in which a sticker-page of unique, readable, barcoded patient identifiers was incorporated in the patient-retained immunisation record (the RTHB) before distribution. Uptake of RTHB identifiers at birth was calculated as the proportion of HIV PCR tests in infants aged <6 days registered with an RTHB identifier over the total number of registered HIV PCR tests. Descriptive analysis of demographic details was performed among infants with two registered HIV PCR tests linked by the RTHB identifier, and performance of the National Health Laboratory Service Corporate Data Warehouse (NHLS CDW)-linking algorithm in matching RTHB-linked results was calculated using a 2 × 2 table. RESULTS: A total of 5 309 HIV PCR birth tests registered with an RTHB identifier were extracted from the NHLS CDW over the 13-month period of the pilot project. The number of registered RTHB identifiers increased from 24 (2% of birth PCR tests) in May 2016, peaking at 728 (56% of birth PCR tests) in May 2017. Among infants with a registered RTHB identifier at birth, 635 (12%) had a subsequent linked HIV PCR test, as indicated by the same RTHB number registered for a later specimen. Demographic details at the time of birth and subsequent PCR test were compared, demonstrating that <4% of infants had exact matches for name, surname, date of birth and sex; 74% of birth tests had variations such as 'born to' or 'baby of ' in place of a first name; surnames matched exactly in 61% of cases; 18% (n=116) of infants had both tests performed at the same facility, of which only 27% (n=31) had the same patient folder number on both test results. CONCLUSIONS: Leveraging RTHBs as unique patient identifiers, even if used temporarily until linkage to other future national unique identifiers, promises to be an effective scalable approach to laboratory-based surveillance, facilitating healthcare provider access to all test results from birth.

Near-real-time tracking of gaps in prevention of mother-to-child transmission of HIV in three districts of KwaZulu-Natal Province, South Africa.

BACKGROUND: Identifying and addressing gaps in the prevention of mother-to-child transmission of HIV (PMTCT) is required if South Africa (SA) is to achieve targets for eliminating MTCT (eMTCT). Potential PMTCT gaps that increase MTCT risk include late maternal HIV diagnosis, lack of or delayed antiretroviral therapy (ART) during pregnancy and breastfeeding, and lack of effective prophylaxis for HIV-exposed infants. OBJECTIVES: To investigate, in near real time, PMTCT gaps among HIV-infected infants in three districts of KwaZulu-Natal Province, SA. METHODS: Between May and September 2016, PMTCT co-ordinators from eThekwini, uMgungundlovu and uMkhanyakude districts received daily email notification of all HIV polymerase chain reaction (PCR)-positive results. Co-ordinators reviewed facility records for each infant to identify gaps in PMTCT care, including maternal age, timing of maternal HIV diagnosis, maternal treatment history and maternal viral load (VL) monitoring. Data were submitted via the mobile phone SMS (text message) service using Rapid Pro technology and analysed in Stata 14. RESULTS: Data on PMTCT gaps were received for 367 (91.8%) of 400 infants with HIV PCR-positive results, within a median time of 12.5 days (interquartile range (IQR) 6 - 23). The median maternal age was 25 years (IQR 22 - 30), with 48 teenage mothers (15 - 19 years). The sample size was too small to determine whether there were significant differences in PMTCT gaps between the 48 teenage mothers and 293 older (20 - 34 years) mothers. Of the mothers, 220 (60.0%) were first diagnosed prior to conception or at their first antenatal care (ANC) visit, and 127 (34.6%) at or after delivery; 137 (37.3%) transmitted HIV to their infants despite receiving >12 weeks of ART. VL results were unavailable for 70.0% of women. Only 41 (17.5%) of women known to be HIV-positive during ANC had confirmed virological suppression. No statistically significant differences in PMTCT gaps were observed between districts, owing to small sample sizes in uMgungundlovu and uMkhanyakude. CONCLUSIONS: The findings highlight the need to improve services during ANC, in particular prioritising maternal VL monitoring. We intend to use improved technology to streamline data collection and reporting towards eMTCT.

Laboratory information system data demonstrate successful implementation of the prevention of mother-to-child transmission programme in South Africa.

BACKGROUND: Monitoring the prevention of mother-to-child transmission (PMTCT) programme to identify gaps for early intervention is essential as South Africa progresses from prevention to elimination of HIV infection in children. Early infant diagnosis (EID) by an HIV polymerase chain reaction (PCR) test is recommended at 6 weeks of age for all HIV-exposed infants. The National Health Laboratory Service (NHLS) performs the PCR tests for the public health sector and stores test data in a corporate data warehouse (CDW). OBJECTIVES: To demonstrate the utility of laboratory data for monitoring trends in EID coverage and early vertical transmission rates and to describe the scale-up of the EID component of the PMTCT programme. METHODS: HIV PCR test data from 2003 to 2012 inclusive were extracted from the NHLS CDW by year, province, age of infant tested and test result and used to calculate EID coverage and early vertical transmission rates to provincial level. RESULTS: Rapid scale-up of EID over the first decade of the PMTCT programme was evident from the 100-fold increase in PCR tests to 350 000 by 2012. In 2012, 73% of the estimated 270 000 HIV-exposed infants requiring an early PCR were tested and the early vertical transmission rate had fallen to 2.4% as a result of successful implementation of the PMTCT programme. CONCLUSIONS: Laboratory data can provide real time, affordable monitoring of aspects of the PMTCT programme and assist in achieving virtual elimination of paediatric HIV infection in South Africa.

Early diagnosis of human immunodeficiency virus-1 infection in infants with the NucliSens EasyQ assay on dried blood spots.

BACKGROUND: More routine laboratories in South Africa are equipped to perform quantitative than qualitative HIV viral detection assays. The accessibility of early infant diagnosis would be improved if a quantitative viral load (VL) assay performed on dried blood spots (DBS) could accurately diagnose HIV-infection. The VL assay routinely used in the country has not previously been assessed on DBS for early infant diagnosis. OBJECTIVES: To determine the accuracy of the NucliSens EasyQ assay (bioMerieux, Lyon, France) on DBS for early infant diagnosis of HIV in a subtype C-infected population. STUDY DESIGN: Stored DBS samples collected from children presenting for HIV testing were analyzed. DBS EasyQ VL results were compared to the child's HIV status as determined by a whole blood HIV DNA PCR result. RESULTS: The EasyQ assay was performed on 235 stored DBS samples from 71 HIV-infected and 164 HIV-uninfected children. Of the 216 infants (children aged 12 months or less) tested, all 52 HIV-infected infants were detected (sensitivity of 100%). Six of 164 HIV-uninfected infants yielded false positive results (specificity 96.3%). All false positive and six of the true positive infants had VL<3.7 log IU/ml. These 12 (5.6%) infants would require repeat testing to differentiate true from false positives. Using a threshold above 3.7 log IU/ml (equivalent to 4 log copies/ml) to define a positive result would yield an accurate diagnosis in 204 (94.4%) infants. CONCLUSIONS: DBS EasyQ VL assays provide an accurate option for early infant diagnosis in low resource settings.

HIV-disclosure in the context of vertical transmission: HIV-positive mothers in Johannesburg, South Africa.

HIV-disclosure among childbearing women remains poorly understood, particularly in sub-Saharan Africa. This paper chronicles disclosure experiences of 31 women attending prevention of mother-to-child HIV transmission services in Johannesburg. Data collection entailed repeat in-depth interviews over a nine-month period. Virtually all women (93.5%) had told at least one person (usually a partner), most voluntarily and within a week of the test result. Secondary disclosure was most likely with female family members, through indirect means and involuntary. Confidentiality breach by primary targets likely contributed to the observed high rates of involuntary secondary disclosure and negative secondary disclosure experiences. For most mothers, voluntary disclosure was driven by the desire to ensure adequate infant care and avoid vertical HIV transmission. The impact of disclosure was not always clear-cut. While most primary disclosure experiences were ultimately constructive, secondary disclosure more likely led to rejection, stigmatization and the withholding of financial support. Our data illustrate the influence of social contextual factors on disclosure patterns and impact. For these mothers, socio-cultural norms, the current media and political environment surrounding HIV/AIDS, household composition and social networks and childbearing status shaped disclosure experiences; sometimes constraining disclosure circumstances and sometimes creating a safe space to disclose. Programmatic implications are also discussed.

Exploring socio-economic conditions and poor follow-up rates of HIV-exposed infants in Johannesburg, South Africa.

In 2002, more than 280,000 HIV-exposed babies were born in South Africa. According to international PMTCT guidelines, these children require follow-up to 12 months of age. Worldwide, the high loss to follow-up rates experienced by PMTCT programs precludes them from identifying and managing HIV-infected children. Socio-economic factors have been identified as potential contributors to poor follow-up. A small descriptive study to examine socio-economic circumstances of women attending the Coronation Women and Children's Hospital PMTCT program was undertaken. Cross-sectional data from 176 women, interviewed at their infants' 12-month visit, was collected using a semi-structured questionnaire. Socio-economic factors such as poverty, geographical relocation and a lack of paternal support may affect the capacity of families to comply with the PMTCT follow-up program. Fifty-seven percent of mothers were unemployed, 25% of fathers did not support their children and only 58% of children remained resident in Johannesburg at the 12-month visit. The lack of follow-up of HIV-infected children denies them access to adequate medical care. Understanding the socio-economic factors that affect the ability of communities to comply with PMTCT programs will assist resource-poor countries in devising strategies to achieve follow-up of HIV-exposed infants.

Psychosocial consequences of early diagnosis of HIV status in vertically exposed infants in Johannesburg, South Africa.

Mother-to-child transmission (MTCT) is the most common source of HIV infection in children. One topic that has received virtually no attention in MTCT-related research and programming is the psychosocial consequences among parents and families of receiving a definitive diagnosis of infant HIV status. This study explored experiences of HIV-infected mothers in Johannesburg, South Africa, regarding infant testing and diagnosis. Data collection entailed a key informant workshop and repeat interviews with a convenience sample of 31 HIV-infected mothers. While early testing was desirable, diagnosis had both beneficial and detrimental psychosocial effects, especially in instances of serodiscordance. Programmatic implications are discussed.

PMTCT from research to reality--results from a routine service.

OBJECTIVES: Assessment of the efficacy of a prevention of mother-to-child transmission (PMTCT) programme in a routine service setting in comparison to a research environment. DESIGN: Descriptive study over a 13-month period utilising retrospective data obtained from hospital records complemented by prospective data on a sample of patients enrolled in a study to determine an affordable HIV diagnostic protocol for infants. SETTING: Routine PMTCT service at Coronation Women and Children's Hospital (CWCH) situated in Johannesburg and affiliated to the University of the Witwatersrand. SUBJECTS: Pregnant women known to be HIV infected who delivered at CWCH from 1 October 2001 to 31 October 2002. OUTCOME MEASURES: The HIV transmission rate to infants, which reflects nevirapine (NVP) delivery and infant feeding practices, and follow-up rates of perinatally exposed children. RESULTS: Of the 8,221 deliveries, 1,234 (15%) occurred in women known to be HIV infected. HIV transmission rates of 8.7% at 6 weeks and 8.9% at 3 months of age in the study population verifies the high rate of NVP administration and the ability of women to formula-feed their babies and abstain from breast-feeding. More than one-third of infants never return for follow-up and more than 70% are lost to follow-up by 4 months of age. CONCLUSIONS: The low HIV transmission rate confirms the efficacy of this routine service PMTCT programme. HIV-infected children are not being identified for medical management as part of PMTCT follow-up. It is imperative that record keeping is improved to facilitate ongoing monitoring.

Hematological reference ranges in black very low birth weight infants.

This study compared hematological reference ranges in black very low birth weight infants to previously published values established predominantly on white subjects. Ninety-four healthy, black, premature babies with a birth weight of 800 to 1500 g at 2-7 days of age were enrolled as part of a study comparing blood transfusions and high- versus low-dose recombinant erythropoietin in anaemia of prematurity. Peripheral venous blood was collected for a full blood count and differential, fetal hemoglobin and erythropoietin levels. The hematological parameters observed in black very low birth weight neonates are similar to previously published reference ranges, except that lower limits of normal were observed for hemoglobin and the red cell indices.

Human immunodeficiency virus type 1 envelope-stimulated interleukin-2 production and survival of infected children with severe and mild clinical disease.

Interleukin (IL)-2 production after stimulation with human immunodeficiency virus type 1 (HIV-1) envelope (Env) peptides, tetanus toxoid, and phytohemagglutinin was measured in peripheral blood mononuclear cells (PBMC) from 25 HIV-1-infected children with mild and 24 with severe clinical disease and from 15 uninfected children. Env-specific IL-2 production was detected in PBMC of 26.5% of HIV-1-infected children but in none of the uninfected. The absence of Env-specific responses at enrollment among infected children was associated with a 6-fold increased risk of mortality within a year, adjusting for clinical severity (P=.04). Among those with severe clinical disease, Env-stimulated IL-2 reactivity in PBMC was negatively correlated with HIV-1 RNA copy numbers in plasma at enrollment and was positively correlated with CD4 T cell percentages 1 year later. HIV-specific cellular immune responses may play a role in containing progression of HIV-1 infection in children, despite early deficits in cell-mediated immunity.

Quantitative enzyme-linked immunosorbent assays for diagnosis of human immunodeficiency virus infection in infancy.

In countries where HIV infection is common and health care resources are limited, identification of HIV-infected infants is difficult because PCR testing is not affordable. Available enzyme-linked immunosorbent assay tests (AXSYM System; Abbott) set a cutoff point of 1; by changing this point to 10, HIV-infected infants can be identified at a young age.

Low molecular weight heparin in the successful treatment of a spontaneous aortic thrombosis in a neonate.

A successfully treated case of a spontaneous aortic thrombosis in a neonate is described as an illustration of the advantages of using low molecular weight heparin (LMWH) over unfractionated heparin (UFH) for anticoagulation therapy. A 5-day-old neonate presented with an abdominal aortic thrombosis detected by echocardiography. Intravenous UFH was commenced following thrombectomy. Poor venous access made monitoring the anticoagulation therapy problematic. Subcutaneous LMWH was substituted for UFH. It requires substantially less monitoring and no intravenous access, has fewer side effects, and allows for much earlier discharge from the hospital. Extensive investigation for a hypercoagulable state revealed no definite cause for the thrombus. The findings of homozygosity for a methylene tetrahydrofolate reductase (MTHFR) mutation and a mildly elevated homocysteine level are interesting but unlikely to account for the thrombotic event in this case. Anticoagulation with LMWH proved effective and more convenient than using UFH.

CD4+ T cell enumeration in HIV infection with limited resources.

The incidence of human immunodeficiency virus (HIV) infection continues to increase in South Africa. Limited resources are available for diagnosis and management of the disease and the development of affordable strategies is required. Absolute CD4 counts are used locally predominantly to monitor disease progression and institute prophylaxis against opportunistic infections. A dramatic increase in demand for CD4 counts prompted an investigation for a more cost-effective flow cytometry method than those currently recommended by the Centers for Disease Control (CDC). CD4 counts generated by two different single tube methods using CD3/CD4/CD8 [1(3)] and CD4 [1(1)] antibodies, respectively, were compared to the CDC recommended 6 tube 2 colour panel [6(2)]. Whole blood analysis using the Coulter Multi-Q-Prep system and an Epics XL Flow Cytometer (Coulter, Hialeah, FL) was performed for each of the three methods. Random samples from HIV positive adult patients were compared. A mean difference in the absolute CD4 counts of less than 10x10(6)/l was generated by both of the alternative panels when compared with the 6(2) panel. The precision of the three methods is comparable. In reagents alone, the 1(3) and 1(1) methods represent a cost saving of 76% and 93%, respectively, over the 6(2) method. The 1(3) and 1(1) panels would permit more affordable CD4 counts to be determined by the gold standard methodology of flow cytometry with no clinically significant sacrifices in accuracy or precision.