Blood culture in the first 6 months of life for the diagnosis of vertically transmitted human immunodeficiency virus infection. The Women and Infants Transmission Study Group

Early Infant Diagnosis Sample Management in Mashonaland West Province, Zimbabwe, 2017

Background

In 2016, Mashonaland West Province had 7.4% (520) dried blood spot (DBS) samples for early infant diagnosis (EID) rejected by the Zimbabwe National Microbiology Reference Laboratory (NMRL). The samples were suboptimal, delaying treatment initiation for HIV-infected children. EID is the entry point to HIV treatment services in exposed infants. We determined reasons for DBS sample rejections and suggested solutions.

Methods

A cause-effect analysis, modelled on Ishikawa, was used to identify factors impacting DBS sample quality. Interviewer-administered questionnaires and evaluation of sample collection process, using Standard Operating Procedure (SOP) was conducted. Rejected samples were reviewed. Epi Info™ was used to analyze findings.

Results

Eleven (73.3%) facilities did not adhere to SOP and (86.7%) did not evaluate DBS sample quality before sending for testing. Delayed feedback (up to 4 weeks) from NMRL extended EID delay for 14 (93.3%) of the facilities. Of the 53 participants, 62% knew valid sample identification. Insufficient samples resulted in most rejections (77.9%). Lack of training (94.3%) and ineffective supervision (69.8%) were also cited.

Conclusion

Sample rejections could have been averted through SOP adherence. Ineffective supervision, exacerbated by delayed communication of rejections, extended EID delay, disadvantaging potential ART beneficiaries. Following this study, enhanced quality control through perstage evaluations was recommended to enhance DBS sample quality.

Infectious Diseases of Poverty in Children: A Tale of Two Worlds

"Infectious diseases of poverty" (IDoP) describes infectious diseases that are more prevalent among poor and vulnerable populations, namely human immunodeficiency virus (HIV) infection, tuberculosis (TB), malaria, and neglected tropical diseases (NTDs). In 2013, 190,000 children died of HIV-related causes and there were 550,000 cases and 80,000 TB deaths in children. Children under age 5 account for 78% of malaria deaths annually. NTDs remain a public health challenge in low- and middle-income countries. This article provides an overview of the major IDoP that affect children. Clinicians must be familiar with the epidemiology and clinical manifestations to ensure prompt diagnosis and treatment.

RNA versus DNA (NucliSENS EasyQ HIV-1 v1.2 versus Amplicor HIV-1 DNA test v1.5) for early diagnosis of HIV-1 infection in infants in Senegal

The objective of this study was to compare the performance of the NucliSENS EasyQ HIV-1 v1.2 platform (bioMérieux, France) to the Amplicor HIV-1 DNA test v1.5 (Roche Molecular Systems, Switzerland) in detecting HIV-1 infection in infants using venipuncture-derived whole blood in tubes and dried blood spots. A total of 149 dried blood spots and 43 EDTA-anticoagulated peripheral blood samples were collected throughout Dakar and other areas in Senegal from infants and children aged 3 weeks to 24 months who were born to HIV-1-infected mothers. Samples were tested using the NucliSENS and Amplicor technologies. The NucliSENS and Amplicor results were 100% concordant using either EDTA-anticoagulated peripheral blood or dried blood spots. Compared to Amplicor, the sensitivity and specificity of the NucliSENS test were 100%. The NucliSENS EasyQ HIV-1 RNA assay performed as well as the Amplicor HIV-1 DNA test in detecting HIV-1 infection in infants. In addition, this platform can give an indication of the viral load baseline. The NucliSENS EasyQ platform is a good alternative for early infant diagnosis of HIV-1 infection.

RNA Detection and Subtype C Assessment of HIV-1 in Infants with Diarrhea in Ethiopia

In the absence of chemoprophylaxis, HIV-1 transmission occurs in 13-42% of infants born to HIV-1 positive mothers. All exposed infants acquire maternal HIV-1 antibodies that persist for up to 15 months, thereby hampering diagnosis. In resource limited settings, clinical symptoms are the indices of established infection against validated laboratorybased markers. Here we enrolled 1200 children hospitalized for diarrheal and other illnesses. 20-25% of those tested, aged 15 months or younger, were found to be HIV-1-seropositive. Where sufficient plasma was available, HIV-1 RNA detection was performed using a subtype-insensitive assay, with 71.1% of seropositive infants presenting with diarrhea showing positive. From sub-typing analysis, we identified that viruses of the C’ sub-cluster were predominated amongst infants. Although this study may overestimate the HIV-1 frequency through testing symptomatic infants, diarrhea can be seen as a useful marker indicating HIV-1 infection in infants less than 15 months old.

Early immunological predictors of neurodevelopmental outcomes in HIV-infected children

BACKGROUND

A previous analysis of children infected with human immunodeficiency virus (HIV) in the Women and Infants Transmission Study showed a strong correlation between low activated CD8(+) T lymphocytes in the first 2 months of life and good immunological prognosis. We sought to extend these observations to neurodevelopmental prognosis.

METHODS

Ninety-eight HIV-infected children born before 1994 with flow cytometric data from the first 2 months of life and adequate neurodevelopmental testing through age 30 months were studied. Children were divided into those with low (<or=5% CD8(+)HLA-DR(+) cells or <or=25% CD8(+)CD38(+) cells) or high (>5% CD8(+)HLA-DR(+) cells or >25% CD8(+)CD38(+) cells) immune activation at 1 and/or 2 months of age. Analysis was performed using survival analysis, Cox's proportional hazard regression, and longitudinal regression models.

RESULTS

Absence of immune activation, measured as <or=5% CD8(+)HLA-DR(+) cells, was strongly associated with better performance on the psychomotor developmental index of the Bayley scales of infant development through the third year of life. This association persisted after adjustment for CD4 cell count, viral load, and progression to acquired immunodeficiency syndrome (P= .005). An association with the mental development index was also present (P= .048). Significant association between neurodevelopmental outcomes and <or=25% CD8(+)CD38(+) cells was not seen.

CONCLUSIONS

In this prospective cohort study of HIV-infected children, there was a significant favorable association of low immune activation in peripheral T cells at age 1 or 2 months, measured by a low percentage of CD8(+)HLA-DR(+) cells, with subsequent psychomotor and mental development. This association was independent of other indices of severity and progression of HIV infection.

Diagnosis of pediatric human immunodeficiency virus infection in resource-constrained settings

The majority of children infected with human immunodeficiency virus live in resource-constrained settings and die without an established diagnosis. Definitive laboratory diagnosis in children younger than 12-18 months requires virologic testing; however, antibody testing is often the only option available. Antibody testing provides a definitive diagnosis in older children but is frequently not used. Children meeting clinical criteria should be treated regardless of availability of laboratory diagnoses.

Effects of Polymorphisms of Chemokine Receptors on Neurodevelopment and the Onset of Encephalopathy in Children with Perinatal HIV-1 Infection

This study examined the effects of chemokine receptor polymorphisms on neurodevelopment and the onset of encephalopathy in children with perinatal HIV-1 infection. Infected children (N = 121) between the ages of I and 72 months were categorized into dichotomous groups (heterozygous or homozygous mutant vs. homozygous wild type) for each chemokine receptor 2 (CCR2) and chemokine receptor 5 (CCR5) allele. Neurodevelopmental measures included the Bayley Scales of Infant Development (BSID)for children age < or = 30 months and the McCarthy Scales of Children's Abilities (MSCA) for children aged > 30 months. A basic linear spline was used to model the mean value at each visit for the relevant test index, with determination of the slope between 4-12 months, 12-30 months, and 31-72 months of age. A mixed model analysis of variance was used to compare differences between slopes (AP) and intercepts (AX) according to the presence or absence of the specified CCR2 or CCR5 polymorphism. Survival analyses were used to compare the onset of encephalopathy by chemokine receptor allelic grouping. After adjusting for potential confounds, statistically significant differences emerged in CCR5-39353, 39356, and 39402. Although the protective effects appeared to be discrete and transient, children with mutant CCR5 genotypes exhibited better neurodevelopmental outcomes than children with the wild type alleles. Chemokine polymorphisms did not appear to impact the onset of encephalopathy. Although possibly a temporary effect, HIV-1 infected children with selected mutant chemokine receptor polymorphims CCR5-39353, 39356, and 39402 may exhibit better neurodevelopmental outcome than children with the wild type allele.

Pediatric HIV infection: diagnostic laboratory methods

The diagnosis of HIV-1 infection in infants and children continues to present challenges. Currently available virologic assays are sensitive and specific and allow early detection of perinatally acquired HIV infection. Identification soon after birth allows for the rapid initiation of antiretroviral therapy and preservation of the infant's immune system. Serologic diagnostic methods, including HIV-ELISA, Western blot, and immunofluorescence Assay can be used to make the diagnosis of HIV infection in infants older than 18 months of age, children, and adolescents. Recently developed rapid tests allow for testing outside clinical sites, provide results in a short period of time, and allow for prompt initiation of effective prophylaxis in cases of exposure particularly maternal to child transmission. We discuss here the diagnostic management of HIV-exposed infants and HIV-infected children.

Antiretroviral resistance in viral isolates from HIV-1-transmitting mothers and their infants

OBJECTIVE

To characterize concordance of resistance mutations to antiretroviral drugs (ART) in mother-infant pairs.

DESIGN

Case series of HIV-transmitting mothers and infants in the Women and Infants Transmission Study, where delivery occurred between April 1994 and December 1999.

METHODS

Reverse transcriptase and protease genes were sequenced in stored viral isolates from 32 mother-infant pairs. Mutations were coded as "pure mutants" where only mutant virus was detected or as "mixtures" where a mixed mutant/wild-type population was identified. ART resistance mutations were compared for concordance between mothers and their infants.

RESULTS

Maternal mutations associated with resistance to nucleoside reverse transcriptase inhibitor (NRTI) and minor protease inhibitor (PI) drugs were typically concordant with that of infant, while those associated with non-nucleoside reverse transcriptase inhibitors (NNRTI) and major PI drugs were not. Of five NRTI-associated maternal mutations observed, three pure mutants corresponded with mutant in the infant, while two wild-type-predominant mixtures corresponded with infant wild type. The only NNRTI-associated mutation observed, K103N, was not transmitted, nor were the two major PI-associated mutations, L90M and V82I/V. Transmission of minor PI-associated mutations was consistent with the sole observed or dominant variant for 20 of 21 mutations.

CONCLUSIONS

For NRTI- and minor PI-associated mutations, transmission was consistent with relative quantity of variants in maternal virus. However, where NNRTI- and major PI-associated mutations were present in three cases, they were not transmitted, even where only mutant virus was detectable in maternal isolates. This is consistent with evidence of loss of transmission with resistance to NNRTI and PI drugs.

Effects of perinatal HIV infection and associated risk factors on cognitive development among young children

OBJECTIVE

We examined the effect of HIV, in combination with other important health and social factors, on the development of cognitive abilities of children perinatally exposed to HIV.

METHODS

Serial cognitive assessments were performed for 117 children who were infected vertically and 422 children who were exposed to but not infected with HIV, in a multicenter, natural history, longitudinal study. Repeated-measures analyses were used to evaluate the neurocognitive development of children between the ages of 3 and 7 years, as measured by the McCarthy Scales of Children's Abilities (MSCA).

RESULTS

Children with HIV infection and class C status scored significantly lower in all domains of cognitive development, across all time points, than did those who were HIV infected without an AIDS-defining illness and those who were HIV exposed but not infected. There were no significant differences between the 2 latter groups in General Cognitive Index or specific domain scores. Rates of change in cognitive development were comparable (parallel) among all 3 groups over a period of 4 years. Factors that were associated consistently and significantly with lower mean scores were HIV status, number of times an examination had been completed previously, primary language, maternal education, and gender. No factors were related to rate of change of any mean domain score.

CONCLUSIONS

An early AIDS-defining illness increased the risk of chronic static encephalopathy during the preschool and early school age years. Children with HIV infection but no class C event performed as well as noninfected children in measures of general cognitive ability. No significantly different profiles of strengths and weaknesses for verbal, perceptual-performance, quantitative, or memory functioning were observed among children with or without HIV infection. A number of factors were found to have significant effects on the mean scores of children in all 3 groups; however, they were not related to the rate at which learning occurred.

Perinatally Acquired HIV-1 Infection: Prevention and Evaluation of HIV-Exposed Infants

Perinatal transmission of human immunodeficiency virus type 1 (HIV-1) is the primary cause of pediatric HIV infections. In recent years, perinatal HIV-1 transmission rates in the United States have declined markedly because of several factors that include enhanced voluntary counseling and HIV-1 testing (VCT) for pregnant women, widespread use of antiretroviral prophylaxis or combination antiretroviral therapy, avoidance of breastfeeding, and elective cesarean delivery. However, perinatal transmission of HIV-1 still occurs, and 300 to 400 infected infants are born annually, primarily because of missed prevention opportunities. The pediatrician plays a vital role in the prevention of perinatal transmission of HIV-1 by identifying newborns born to infected mothers who were not tested during pregnancy, administering antiretroviral prophylaxis, and ensuring follow-up to confirm or exclude the diagnosis of HIV-1 infection in early infancy. This article reviews recent advances in the prevention of perinatal transmission of HIV-1, discusses evaluation and treatment of infants exposed to HIV-1, and highlights certain unique features of HIV-1 infections in infants, with a focus on early diagnosis, clinical manifestations, treatment, and prognosis.

Risk factors for in utero and intrapartum transmission of HIV

OBJECTIVE

To identify predictors of in utero and intrapartum HIV-1 transmission in infants born in the Women and Infants Transmission Study between 1990 and 2000.

METHODS

In utero HIV-1 infection was defined as an infant with the first positive HIV-1 peripheral blood mononuclear cell culture and/or DNA polymerase chain reaction assay at 7 days of age or younger; intrapartum infection was defined as having a negative HIV-1 culture and/or DNA polymerase chain reaction assay at 7 days of age or younger and the first positive assay after 7 days of age.

RESULTS

Of 1709 first-born singleton children with defined HIV-1 infection status, 166 (9.7%) were found to be HIV-1 infected; transmission decreased from 18.1% in 1990-1992 to 1.6% in 1999-2000. Presumed in utero infection was observed in 34% of infected children, and presumed intrapartum infection, in 66%. Among infected children, the proportion with in utero infection increased over time from 27% in 1990-1992 to 80% (4 of 5) in 1999-2000 (P = 0.072). Maternal antenatal viral load and antiretroviral therapy were associated with risk of both in utero and intrapartum transmission. Controlling for maternal antenatal viral load and antiretroviral therapy, low birth weight was significantly associated with in utero transmission, while age, antenatal CD4 cell percentage, year, birth weight, and duration of membrane rupture were associated with intrapartum transmission.

CONCLUSION

Although there have been significant declines in perinatal HIV-1 infection over time, there has been an increase in the proportion of infections transmitted in utero.

Differences in neuropsychological performance associated with ethnicity in children with HIV-1 infection: preliminary findings

This study investigated the relationship between ethnicity (African American and European American) and neuropsychological performance in two specific neuropsychological domains (language and speed of information processing) in a group of HIV-1+ children. The Expressive One-Word Picture Vocabulary Test-Revised and the Rapid Color Naming subtest of the Comprehensive Test of Phonological Processing were administered to 5- to 7-year-old children (n = 22) as part of a comprehensive research or clinical protocol. African American children scored lower than European American children (p < .05) on both procedures. The observed performance difference emerged despite the fact that there were no group differences in age, immunologic clinical categories, intellect, level of maternal education, or CD4+ percentage and after using stringent exclusionary criteria, including history of enrollment in special education services and the presence of other chronic medical conditions. The implications of such findings are discussed within biological and demographic frameworks.

Morbidity and mortality during the first two years of life among uninfected children born to human immunodeficiency virus type 1-infected women: the women and infants transmission study

OBJECTIVE

We evaluated morbidity and mortality during the first 2 years of life among children born to human immunodeficiency virus-(HIV) type 1-infected women enrolled in the Women and Infants Transmission Study (WITS) during an 11-year period (1990-2001).

DESIGN AND METHODS

As part of WITS, evaluations were performed at birth and at 1, 2, 4, 6, 9, 12, 18 and 24 months of age. Growth, hospitalization and the incidence of clinical disease were assessed regularly.

RESULTS

Data regarding 1118 children born to HIV-infected women (955 HIV-uninfected children and 163 HIV-infected children) were analyzed. Fewer changes in the caretaker of the child and fewer in utero exposures to drugs, tobacco and alcohol occurred in the latter periods of the study (all P values for time trend analyses <0.01). The percentages of HIV-uninfected children with poor weight gain (44 of 767; 5.7%), short stature (32 of 703; 4.5%) and wasting (27 of 792; 3.4%) were higher than expected for the general population. Two or more changes in caretaker were associated with all growth deficiencies except wasting, and fetal exposure to tobacco was associated with height abnormalities. Anemia was common and was associated with receipt of zidovudine prophylaxis. Morbidity and mortality decreased during the study period. For the uninfected children, a decrease in class A events (Kaplan-Meier rates: group 1, 22.3%; group 2, 6.8%; group 3, 4.2%; P < 0.001) and class C events and death (Kaplan- Meier event rates: group 1, 2.0%; group 2, 1.7%; group 3, 0.2%; P = 0.062) during the first 2 years of life account for the differences in the curves over time.

CONCLUSIONS

During an 11-year period, morbidity and mortality during the first 24 months of life decreased substantially for children born to HIV-infected women.

Management of the infant born to a mother with HIV infection

In countries with adequate resources, rates of perinatal mother-to-child-transmission (MTCT) of HIV can be as low as 2% or lower. To achieve this low rate of MTCT of HIV requires identification of women with HIV infection early in pregnancy, treatment of the pregnant woman with appropriate combination antiretroviral therapy, special interventions in maternal management during labor and delivery, and appropriate care of the newborn infant. Although many of the steps in preventing HIV MTCT fall to obstetrical care providers, practitioners focused on care of the newborn also play an important role in the prevention of perinatal HIV MTCT, follow-up to identify or exclude HIV infection in the infant, and ongoing care for children and families affected by HIV.

Simple DNA extraction method for dried blood spots and comparison of two PCR assays for diagnosis of vertical human immunodeficiency virus type 1 transmission in Rwanda

Dried blood spots (DBS) on filter paper facilitate the collection, transport, and storage of blood samples for laboratory use. A rapid and simple DNA extraction procedure from DBS was developed and evaluated for the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection in children by an in-house nested-PCR assay on three genome regions and by the Amplicor HIV-1 DNA prototype assay version 1.5 (Roche Molecular Systems). A total of 150 samples from children born to HIV-1-infected mothers were collected in Kigali, Rwanda, in parallel as DBS and as peripheral blood mononuclear cell (PBMC) pellets. The results obtained on DBS by the two PCR assays were compared to the results of nested PCR on PBMCs. Of 150 PBMC samples, 10 were positive, 117 were negative, and 23 were indeterminate for HIV-1 infection. In DNA extracted from filter papers and amplified by using the in-house nested PCR, 9 of these 10 positive samples (90%) were found to be positive, and 1 was found to be indeterminate (only the pol region could be amplified). All of the negative samples and all of the 23 indeterminate samples tested negative for HIV-1 infection. When we used the Amplicor DNA test on DBS, all of the 10 PBMC-positive samples were found to be positive and all of the 23 indeterminate samples were found to be negative. Of the PBMC-negative samples, 115 were found to be negative and 2 were found to be indeterminate. We conclude that this simple rapid DNA extraction method on DBS in combination with both detection methods gave a reliable molecular diagnosis of HIV-1 infection in children born to HIV-infected mothers.

Zidovudine Resistance Phenotype and Risk of Perinatal HIV-1 Transmission in Zidovudine Monotherapy???Treated Mothers With Moderately Advanced Disease

The association of phenotypic zidovudine resistance with perinatal transmission was evaluated in 74 zidovudine-treated mothers enrolled in the Women and Infants Transmission Study through September 1994. Women in the sample had moderately advanced disease, with a median CD4+ cell count of 271/microL and a median plasma HIV-1 RNA level of 39,811 copies/mL. Factors independently associated with zidovudine resistance at delivery (50% inhibitory concentration [IC50], >/=0.1 microM) in multiple logistic regression included prepregnancy zidovudine use, high log plasma HIV-1 RNA level, and low CD4+ cell count. Of 74 mothers, 16 (22%) transmitted HIV-1 to their infants. After adjustment for duration of membrane rupture and CD8+ cell count, zidovudine resistance (IC50 range, 0.01-2.2 microM) was associated with an increased odds of transmission (ORadj, 1.25 per 0.1 microM; 95% confidence interval, 1.01-1.54), suggesting a decreased effect of prenatal zidovudine on preventing transmission in mothers infected with zidovudine-resistant virus. However, when the analysis was limited only to those mothers infected with virus containing zidovudine resistance mutations, no association between phenotypic resistance and transmission remained, indicating that phenotype may not provide significant additional information in predicting transmission where resistance genotype is known.

Quantitative RNA testing for diagnosis of HIV-infected infants

Quantitative HIV RNA testing was used for diagnosis in 156 HIV-exposed non-breast-fed infants at less than 6 months of age (54 infected, 102 uninfected) enrolled in the Perinatal AIDS Collaborative Transmission Study. Sensitivity was 29% in the first week, 79% at 8 to 28 days of age, and >90% at 29 days of age and thereafter; specificity was 100% in all periods, except at 29 to 60 days of age, when specificity was 93%. Neither sensitivity nor specificity was significantly affected by maternal or infant zidovudine (ZDV) treatment, even though infant viral loads were lower during the first 6 weeks in infants who received perinatal ZDV prophylaxis ( p=.005). Paired analysis of DNA and RNA measurements revealed no advantage for either test. Quantitative RNA testing can be used for diagnosis in HIV-exposed infants, recognizing the chance for a false-positive test result. It may be most useful as a confirmatory test in infants with another positive diagnostic test result.

High rates of behavioral problems in perinatally HIV-infected children are not linked to HIV disease

OBJECTIVE

Descriptive studies and clinical reports have suggested that human immunodeficiency virus (HIV)-positive children are at risk for behavioral problems. Inadequate control groups and sample sizes have limited the ability of investigators to consider multiple influences that place HIV-positive children at risk for poor behavioral outcomes. We examined the unique and combined influences of HIV, prenatal drug exposure, and environmental factors on behavior in children who were perinatally exposed to HIV.

METHODS

Participants included 307 children who were born to HIV-positive mothers (96 HIV infected and 211 seroreverters) and enrolled in a natural history, longitudinal study of women to infant HIV transmission. Caregivers completed parent behavioral rating scales, beginning when the children were 3 years old. Data were also collected on prenatal drug exposure; child age, gender, and ethnicity; caregiver relationship to child; and birth complications.

RESULTS

Multivariate analyses comparing the HIV-infected children with perinatally exposed but uninfected children from similar backgrounds failed to find an association between either HIV status or prenatal drug exposure and poor behavioral outcomes. The strongest correlates of increased behavioral symptoms were demographic characteristics.

CONCLUSIONS

This study suggests that although a high prevalence of behavioral problems does exist among HIV-infected children, neither HIV infection nor prenatal drug exposure is the underlying cause. Rather, other biological and environmental factors are likely contributors toward poor behavioral outcomes.

New methods for the detection of HIV

In the past few years, several strides have been made in the ability to detect the presence of HIV-1 and HIV-2. This article discusses recent advances in serologic testing, including routine ELISA and Western blot tests, rapid HIV tests, home collection kits, and HIV tests using nonserum samples. The clinical application of nucleic acid-based tests also is discussed. Finally, appropriate use of these tests in both acute HIV-1 infection and in infants is reviewed.

Early diagnosis of paediatric HIV-1 infection among African breast-fed children using a quantitative plasma HIV RNA assay

OBJECTIVE

To evaluate the performance of a quantitative plasma HIV-1 RNA assay for HIV infection diagnosis among African breast-fed children.

METHODS

Serial plasma specimens collected in the first week, at day 45-90, 6 months and 9-12 months of age from HIV-exposed children born to HIV-1-infected women enrolled in the DITRAME ANRS 049a perinatal intervention trial (Abidjan, Côte d'Ivoire) were tested for HIV-1 plasma RNA using a branched DNA (bDNA) assay. Sensitivity and specificity of this RNA test were assessed in comparison with a qualitative DNA polymerase chain reaction (PCR) performed on the same blood samples and allowing a reliable detection of the predominant subtype A.

RESULTS

Among 91 samples from 53 infected children which tested positive by DNA PCR, the sensitivity of the bDNA test was 100% [95% confidence interval (CI), 96.0-100.0] at < or = 8 days (n = 19), 6-12 weeks (n = 43), 6 months (n = 26), and 9-12 months (n = 3). The median plasma HIV-1 RNA viral load ranged from 242 000 copies/ml at < or = 8 days to more than 500 000 copies/ml at day 45-90 and at 6 months. Of 106 specimens from 106 uninfected children who were DNA PCR- negative at month 3 or 6 of age, HIV-1 RNA was undetectable in 103, yielding an overall specificity for the bDNA test of 97.2% (95% CI, 92.0-99.4). The viral load in the three remaining samples with false-positive results was low (410, 937 and 3752 copies/ml, respectively).

CONCLUSIONS

The quantitative bDNA assay appears a suitable tool for early, reliable and easy diagnosis of paediatric HIV-1 infection among a population of African breast-fed children.

Timing of perinatal human immunodeficiency virus type 1 infection and rate of neurodevelopment. The Women and Infant Transmission Study Group

BACKGROUND

Identifying HIV-1-infected children who are at greatest risk for disease-related morbidities is critical for optimal therapeutic as well as preventive care. Several factors have been implicated in HIV-1 disease onset and severity, including maternal and infant host characteristics, viral phenotype and timing of HIV-1 infection. Early HIV-1 culture positivity, i.e. intrauterine infection, has been associated with poor immunologic, virologic and clinical outcomes in children of HIV-infected women. However, a direct effect of timing of infection on neurodevelopmental outcome in infancy has not yet been identified.

METHODS

Serial neurodevelopmental assessments were performed with 114 infants vertically infected with HIV-1 in a multicenter natural history, longitudinal study. Median mental and motor scores were compared at three time points. Longitudinal regression analyses were used to evaluate the neurodevelopmental functioning of children with early positive cultures and those with late positive cultures.

RESULTS

Early infected infants scored significantly lower than late infected infants by 24 months of age and beyond on both mental (P = 0.05) and motor (P = 0.03) measures. Early HIV-1 infection was associated with a decline in estimated motor scores of 1 standard score point per month compared with 0.28 point in the late infected group (P < 0.02). Estimated mental scores of the early infected group declined 0.72 point/ month, whereas the average decline of the late infected group was 0.30 point/month (P < 0.13).

CONCLUSION

Early HIV-1 infection increases a child's risk for poor neurodevelopmental functioning within the first 30 months of life.

Early diagnosis of HIV-1-infected infants in Thailand using RNA and DNA PCR assays sensitive to non-B subtypes

OBJECTIVES

To evaluate the sensitivity and specificity of RNA and DNA polymerase chain reaction (PCR) for early diagnosis of perinatal HIV-1 infection and to investigate early viral dynamics in infected infants.

DESIGN

A cohort study of 395 non-breastfed infants born to HIV-infected mothers in a randomized clinical trial of short-course antenatal zidovudine.

METHODS

Infant venous blood specimens collected at birth, 2 months, and 6 months of age were tested by qualitative DNA and quantitative RNA PCR (Roche Amplicor). To determine sensitivity and specificity of DNA and RNA PCR, results were compared with later DNA PCR results and to antibody results at 18 months. The HIV-1 subtype of the mother's infection was determined by peptide serotyping.

RESULTS

In the study, 92% of mothers were infected with subtype E. DNA PCR sensitivity was 38% (20 of 53) at birth, and 100% at 2 months (53 of 53) and 6 months (47 of 47). RNA PCR sensitivity was 47% (25 of 53) at birth and 100% (53 of 53) at 2 months. All samples that tested DNA-positive tested RNA-positive. Specificity was 100% for both DNA and RNA testing at all timepoints. For infected infants, the median viral load of RNA-positive specimens was 407,000 copies/ml (5.6 log10) at birth, 3, 700,000 copies/ml (6.6 log10) at 2 months, and 1,700,000 copies/ml (6.2 log10) at 6 months. Infant RNA levels at 2 and 6 months did not differ by maternal zidovudine exposure, or RNA level at birth.

CONCLUSION

This RNA PCR assay performed well for diagnosing perinatal HIV subtype E infection, detecting nearly half of infected infants at birth, and 100% at 2 and 6 months, with 100% specificity. Infected infant viral RNA levels were very high at 2 and 6 months, and were unaffected by maternal zidovudine treatment.

HIV-1 genotypic zidovudine drug resistance and the risk of maternal--infant transmission in the women and infants transmission study. The Women and Infants Transmission Study Group

OBJECTIVES

Although the treatment of pregnant women and their infants with zidovudine (ZDV) has been remarkably effective in preventing the perinatal transmission of human HIV-1, many potentially preventable infections still occur. To examine whether the risk of perinatal infection is increased among women who carry ZDV-resistant HIV-1, the role of genotypic ZDV resistance in perinatal transmission was evaluated.

METHODS

The reverse transcriptase (RT) region of clinical isolates from culture supernatants of 142 HIV-1-infected women enrolled in the Women and Infants Transmission Study (WITS), who had been treated with ZDV during pregnancy was sequenced. Results from genotypic sequencing were linked to demographic, laboratory, and obstetrical databases, and the magnitude of association of having consensus drug-resistant HIV-1 RT mutations with transmission was estimated.

RESULTS

Twenty-five per cent (34/142) of maternal isolates had at least one ZDV-associated resistance mutation. A lower CD4 cell percentage and count (P= 0.0001) and higher plasma HIV-1 RNA (P=0.006) were associated with having any ZDV resistance mutation at delivery. Having any RT resistance mutation [odds ratio (OR): 5.16; 95% confidence interval (CI): 1.40, 18.97; P=0 0.01], duration of ruptured membranes [OR: 1.13 (1.02, 1.26) per 4 h duration; P= 0.02], and total lymphocyte count [OR: 1.06 (1.01, 1.10) per 50 cells higher level; P=0.009] were independently associated with transmission in multivariate analysis.

CONCLUSION

Maternal ZDV resistant virus was predictive of transmission, independent of viral load, in these mothers with moderately advanced HIV-1 disease, many of whom had been treated with ZDV before pregnancy.

Diagnosis of HIV infection in children

Many advances have been made in the area of HIV diagnostics. Commercially available virologic assays are sensitive and specific for the early detection of HIV in perinatal infection. The timing of the transmission of HIV from mother to child (in utero, at the time of birth, or postnatally by breast-feeding) is a critical consideration in the appropriate diagnosis of infants. Several algorithms can be used to define early infection and the potential timing of acquisition of infection that combine different assays and timing of specimens. The use of virologic assays, including HIV DNA PCR and HIV RNA detection methods and culture, can define and rule out infection in infants less than 18 months of age. Serologic diagnostic methods, including HIV ELISA, immunofluorescence, and western blot assays, can be used to diagnose infants more than 18 months of age, when transplacental antibody has disappeared in uninfected HIV-exposed infants. The challenge of the early and accurate diagnosis of perinatally HIV-exposed infants is the use of new assays to detect different HIV subtype infections that are prevalent in developing countries. Rapid, simple, and inexpensive serologic and virologic assays are being developed for worldwide use.

Maternal and infant factors predicting disease progression in human immunodeficiency virus type 1-infected infants. Women and Infants Transmission Study Group

BACKGROUND

Infants with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection have widely variable courses. Previous studies showed that a number of maternal and infant factors, when analyzed separately, are associated with infant HIV-1 disease progression. In this study, clincal, virologic, and immunologic characteristics in the mothers and infants were examined together to determine the predictors of disease progression by 18 months of age and the associations with rapid progression during the first 6 months of life.

METHODS

One hundred twenty-two HIV-1-infected women whose infants were HIV-1 infected were identified from the Women and Infants Transmission Study (WITS) cohort. WITS is a longitudinal natural history study of perinatal HIV-1 infection carried out in 6 sites in the continental United States and in Puerto Rico. The women were enrolled during pregnancy and their infants were enrolled at the time of delivery and followed prospectively by a standardized protocol. Virologic and immunologic studies were performed in laboratories certified by National Institutes of Health-sponsored quality assurance programs. Maternal factors in pregnancy were used as potential predictors of infant disease progression (progression to Centers for Disease Control and Prevention [CDC] Clinical Class C disease or death by 18 months of age) or as correlates of progression at <6 months of age. Infant factors defined during the first 6 months of life were used as potential predictors of progression during 6 to 18 months of age and as correlates of progression at <6 months of age.

RESULTS

Progression by 18 months of age occurred in 32% of infants and by 6 months of age in 15%. Maternal characteristics that, by univariate analysis, were significant predictors of infant disease progression by 18 months of age were elevated viral load, depressed CD4(+)%, and depressed vitamin A. CD8(+)%, CD8(+) activation markers, zidovudine (ZDV) use, hard drug use, and gestational age at delivery were not. When examined in a combined multivariate analysis of maternal characteristics, only vitamin A concentration independently predicted infant progression. Infant characteristics during the first 6 months of life that, by univariate analysis, were associated with disease progression included elevated mean viral load at 1 to 6 months of age, depressed CD4(+)%, CDC Clinical Disease Category B, and growth delay. Early HIV-1 culture positivity (<48 hours), CD8(+)%, CD8(+) activation markers, and ZDV use during the first month of life did not predict progression. Multivariate analysis of infant characteristics showed that the only independent predictors were progression to CDC Category B by 6 months of age (odds ratio [OR], 5.80) and mean viral load from 1 to 6 months of age (OR, 1.99). The final combined maternal and infant analysis included the significant maternal and infant characteristics in a multivariate analysis. It showed that factors independently predicting infant progression by 18 months of age were progression to CDC Category B by 6 months of age (OR, 5.80) and elevated mean HIV-1 RNA copy number at 1 to 6 months of age (OR, 1.99). The characteristics associated with rapid progression to CDC Category C disease or death by 6 months of age were also examined. The only maternal characteristic associated with progression by 6 months in multivariate analysis was low maternal CD4(+)%. The infant characteristics associated with progression by 6 months of age in multivariate analysis were depressed mean CD4(+)% from birth through 2 months and the presence of lymphadenopathy, hepatomegaly, or splenomegaly by 3 months. Infant ZDV use was not assocciated with rapid progression.

CONCLUSION

The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immun

Sensitivity and specificity of a qualitative RNA detection assay to diagnose HIV infection in young infants. Perinatal AIDS Collaborative Transmission Study

OBJECTIVE

To evaluate the sensitivity and specificity of an RNA detection assay for diagnosing perinatal HIV infection.

METHODS

Plasma and serum specimens taken during the first 3 months of life from HIV-infected and uninfected children enrolled in a cohort study were assayed for HIV RNA using the qualitative nucleic acid sequence-based amplification (NASBA) kit. Sensitivity, specificity, and predictive values were calculated. NASBA results from infected children were compared with DNA PCR results from the same blood samples. Autoantibody patterns of suspected false-positive specimens were compared with those of subsequent specimens from the same child to exclude specimen labelling errors.

RESULTS

Amongst 131 specimens from 105 HIV-infected children, the sensitivity of the qualitative NASBA assay was 13 out of 34 [38%; 95% confidence interval (CI), 22-56] at < 7 days, 56 out of 58 (97%; 95% CI, 88-100) at 7-41 days, and 37 out of 39 (95%; 95% CI, 83-99) at 42-93 days of life. Of 252 specimens from 206 uninfected children, six tested positive and one tested indeterminate by NASBA. Four of these positive specimens had discordant autoantibody patterns suggesting mislabelling; excluding these, the test specificity was 245 out of 248 (99%; 95% CI, 97-100). Amongst 128 paired specimens from infected children, NASBA results were more often positive than those from DNA PCR (103 versus 92; P=0.01). Amongst infants with specimens drawn in the first week of life, the proportion born after > 4 h of membrane rupture was greater amongst those testing negative (81%) than those testing positive (46%; P=0.05).

CONCLUSIONS

The qualitative NASBA RNA assay is highly specific and more sensitive than DNA PCR. Qualitative RNA assays may be useful for diagnosing and excluding perinatal HIV infection in children after the first week of life for such purposes as initiating antiretroviral therapy and other treatment, resolving parental uncertainty, determining timing of transmission, and providing endpoints for intervention trials.

Perinatal human immunodeficiency virus-1 transmission and intrauterine growth: a cohort study in Butare, Rwanda

OBJECTIVE

To study the association of perinatal human immunodeficiency virus (HIV)-1 transmission with birth outcomes, including birth weight, gestational age, ponderal index, head circumference, and weight/head ratio.

METHODS

Data from a prospective cohort study of 627 pregnant women and their infants in Butare, Rwanda, from October 1989 until April 1994 were analyzed. A total of 318 HIV-1-infected and 309 seronegative women were enrolled during pregnancy and gave birth to 590 live singletons. Multiple linear regression modeling was used to assess the association of mother-child HIV status with several birth outcome measures.

RESULTS

Unadjusted mean birth weight of HIV- infected infants was 235 g (95% confidence interval [CI] = 94 to 376 g) less than that of HIV-uninfected infants born to HIV-positive mothers (the reference group). After adjustment for gestational age, socioeconomic factors, maternal age, parity, hematocrit, and anthropomorphic measures, mean birth weight of HIV-infected infants was 154 g (95% CI = 38 to 271 g) lower than that of the reference group. When infants born to HIV-seronegative mothers were compared with the reference group, mean birth weights did not differ. Adjusted models resulted in estimates of mean head circumference 0.6 cm smaller (95% CI = 0.2 to 1.1 cm), ponderal index 0.14 lower (95% CI = 0.05 to 0.23), weight/head ratio 3.5 lower (95% CI = 0.5 to 6.4), and gestational age 0.5 weeks shorter (95% CI = 0.1 to 0.9 weeks) for HIV-infected infants than for the reference group.

CONCLUSIONS

After adjustment for potential confounding variables, this study showed statistically significant differences in birth weight, gestational age, ponderal index, and weight/head ratio when HIV-infected infants were compared with noninfected infants born to HIV-positive mothers. HIV-1, mother-to-child transmission, Africa, intrauterine growth, birth weight, gestational age, ponderal index.

Disease progression in a cohort of infants with vertically acquired HIV infection observed from birth: the Women and Infants Transmission Study (WITS)

BACKGROUND

The Women and Infants Transmission Study is an ongoing prospective cohort study of HIV-infected pregnant women and their infants. We used the 1994 U.S. Centers for Disease Control and Prevention (CDC) classification system for HIV infection in children to describe HIV disease progression in 128 HIV-infected children, and examined maternal and infant characteristics associated with disease course.

METHODS

The Kaplan-Meier method was used to calculate probabilities of entry into CDC clinical classes A, B, and C (mild, moderate, and severe HIV disease); CDC immunologic stages 2 and 3; and death. Relative risks of progression for selected predictor events were estimated using the Cox proportional hazards model.

RESULTS

With a median 24 months of follow-up, the median ages at entry into clinical classes A, B and C were 5, 11, and 48 months, respectively. Increased risk of progression to class C was seen in infants who had: onset of class B events (p < .001); progression to immunologic stage 2 (p < .001) or 3 (p < .001); early culture positivity (in first 48 hours, p < .01; in first 7 days, p = .03); and early appearance (within the first 3 months of life) of lymphadenopathy, hepatomegaly, or splenomegaly (p < .001).

CONCLUSIONS

Reaching specific clinical or immunologic stages were strong predictors of progression to AIDS or death. Early onset of clinical signs (onset of lymphadenopathy, hepatomegaly, or splenomegaly < or =3 months of age), and early culture positivity (within the first 48 hours or within the first week of life), defined the infant with highest risk of disease progression.

Administration of 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) for prevention of perinatal simian immunodeficiency virus infection in rhesus macaques

Simian immunodeficiency virus (SIV) infection of newborn macaques is a useful animal model to explore novel strategies to reduce perinatal human immunodeficiency virus (HIV) infection. The availability of two easily distinguishable virus isolates, SIVmac251 and the simian/human immunodeficiency virus chimera SHIV-SF33, allows tracing the source of infection following inoculation with both viruses by different routes. In the present study, we evaluated the efficacy of pre- and postinoculation treatment regimens with 9-[2-(phosphonomethoxy)propyl]adenine (PMPA) to protect newborn macaques against simultaneous oral SIVmac251 and intravenous SHIV-SF33 inoculation. Untreated newborns became persistently infected following virus inoculation. When three pregnant macaques were given a single subcutaneous dose of PMPA 2 hr before cesarean section, their newborns became SIV-infected following SIV and SHIV inoculation shortly after birth. In contrast, when four newborn macaques were inoculated simultaneously with SIV and SHIV, and started immediately on PMPA treatment for 2 weeks, only one animal became persistently SIV-infected; the remaining three PMPA-treated newborns, however, had some evidence of an initial transient virus infection but were seronegative and healthy at 8 months of age. Our data demonstrate that PMPA treatment can reduce perinatal SIV infection and suggest that similar strategies may also be effective against HIV.

The immunogenicity of Haemophilus influenzae type b conjugate vaccines in children born to human immunodeficiency virus-infected women. Women and Infants Transmission Study Group

BACKGROUND

Immunocompromise caused by HIV-1 infection increases the importance of receipt of routine childhood vaccines to prevent infections such as invasive Haemophilus influenzae type B (Hib) disease. The objectives of the study were to evaluate the immunogenicity of Hib conjugate vaccines among HIV-infected children according to clinical and immunologic disease progression as well as viral load.

METHODS

The concentration of antibody to polyribosylribitol phosphate (PRP) was measured at approximately 9 and 24 months of age in plasma specimens from children of HIV-infected women enrolled in the Women and Infants Transmission Study.

RESULTS

Among 227 children (35 HIV-infected, 192 uninfected) at the 9-month study visit who were known to have received age-appropriate immunization with CRM197 mutant Corynebacterium diphtheriae protein-conjugated Hib vaccine, geometric mean antibody concentrations were lower among HIV-infected children (1.64 microg/ml) than among uninfected children (2.70 microg/ml), although the difference was not statistically significant. Anti-PRP antibody concentrations did not vary significantly among these HIV-infected children with predominantly mild-moderate disease progression according to clinical category, immunologic stage or viral load (P > or = 0.48). The proportion of children with antibody concentrations > or = 1.0 microg/ml did not vary significantly according to HIV infection status (73% uninfected, 74% infected) or, if infected, clinical or immunologic disease progression or viral load. Similar results were obtained among 127 children (17 HIV-infected, 110 uninfected) eligible for analysis at the 24-month study visit. Changes in antibody concentrations over time (between 9 and 24 months of age) did not differ significantly among 10 HIV-infected as compared with 72 uninfected children (P=0.81).

CONCLUSIONS

These results suggest that HIV-infected children with predominantly mild-moderate disease progression respond reasonably well in terms of a quantitative antibody response to Hib conjugate vaccines during the first 2 years of life. Research to further characterize the immune response to Hib conjugate vaccines and to further delineate the "durability" of anti-PRP antibody concentrations beyond 2 years of life should be pursued.

HIV vertical transmission rate determinations are subject to differing definitions and therefore different rates. The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group

The HIV infection status of a cohort of 600 prospectively followed children born to HIV infected mothers was determined using HIV peripheral blood culture tests at 0, 3, and 6 months of age, HIV serology at > or = 15 months, and CDC AIDS criteria. We estimated transmission rates using five methods which differed in how HIV indeterminates are handled. These methods were applied at two points in time to illustrate effects of length of follow-up of the cohort on results. In January 1997, 30 months after the last birth, transmission rate estimates ranged from 15.5% (known positives/known positives x known negatives) to 18.1% (known positives x those with one positive culture x deaths/entire cohort minus those lacking negative cultures at age > or = 5 months). Estimates ranged from 14.8% to 20.7% using the subcohort of 284 children followed > or = 12 months as of May 1993. These results indicate that methods for assigning HIV infection status and for handling HIV indeterminates should be carefully defined when estimating transmission rates.

Primary care for children with human immunodeficiency virus infection

Pediatric human immunodeficiency virus (HIV) infection is now the seventh leading cause of death in U.S. children 1 to 14 years of age and the leading cause of death in children 2 to 5 years of age in many U.S. cities. The key to enhancing the quality and duration of life in HIV-infected children is to recognize and diagnose HIV infection as early as possible and to initiate prophylactic and antiretroviral therapies. Most of the medical treatment of these children can be conducted in a primary care setting if (a) primary care practitioners are informed of current treatment regimens and (b) adequate pediatric HIV consultation service is available. This article reviews the primary care of HIV-infected children including early diagnosis, current treatment options, and the complex psychosocial issues associated with caring for these children.

Lymphocyte phenotyping in infants: maturation of lymphocyte subpopulations and the effects of HIV infection

Changes in the distribution of lymphocyte subpopulations in infants with perinatally acquired HIV infection are confounded by the rapid changes that are the result of normal maturation of the immune system. We describe the changes in seven lymphocyte phenotypes (CD3+ CD4+, CD3+ CD8+, CD8+ HLA- DR+, CD8+ CD38+, CD8+ CD57+, CD3-/ CD16+ 56+, and CD19+) over the first 2 years of life in 390 HIV-1 exposed but uninfected and 98 HIV-1-infected infants enrolled in the Women and Infants Transmission Study. The greatest changes in uninfected infants were declines in the CD3+ CD4+ lymphocytes and increases in CD8+ HLA- DR+ and CD19+ lymphocytes. All phenotypes were affected by HIV infection but the greatest changes were declines in the CD3+ CD4+ subset and increases in the CD3+ CD8+ and CD8+ HLA- DR+ subsets. Thus, this study provides reference data for the maturational changes in lymphocyte phenotypes in HIV-exposed but uninfected infants and describes the overall changes that occur with perinatally acquired HIV infection.

Pediatric HIV-1 infection

Although there is optimism that with the prospective identification and treatment of HIV-1-infected pregnant women the incidence of pediatric infection can be diminished, currently the number of HIV-1-infected children continues to rise. Improvements in early diagnosis provide the potential for early intervention, and the advent of more potent antiretroviral agents provides the hope of better treatment strategies to slow disease progression in HIV-1-infected children.

Vertical transmission of HIV in New York State: a basis for statewide testing of newborns

Infants (n = 313) of HIV-infected mothers were enrolled (mean age 1.9 weeks, range 0-8 weeks) in a 3-year prospective study of vertical transmission. Fifty-six infants (17.9%) had laboratory and clinical evidence of HIV infection. Polymerase chain reaction (PCR) provided early and reliable identification of infected infants. Thirty-one of the 56 infected infants had specimens submitted when the infants were 4 weeks of age or less and 30 (97%) tested PCR positive. This percentage increased to 100% by 8 weeks of age when 51 of the 56 infected infants had specimens tested for that time period. Immune complex dissociation (ICD) antigen testing was a sensitive method for diagnosis of infection but only in infants older than 1 month. p24 antigen testing, although free of false positives, is less sensitive than either of the other methods. Among surrogate markers of HIV infection, elevation of soluble CD8 levels precedes an increase in immunoglobulin levels or a decline in CD4 T lymphocytes. Vertical transmission is significantly lower in Central and Western New York State than other regions. Transmission is significantly higher in low birthweight babies and in infants whose mothers have CD4 counts < 500. This study provided the basis for establishing a Pediatric HIV PCR Testing Service for the early diagnosis of HIV infection in neonates.

Elevated CD8+DR+ lymphocytes in HIV-exposed infants with early positive HIV cultures: a possible early marker of intrauterine transmission. Women and Infants Transmission Study Group

The associations among timing of maternal-fetal human immunodeficiency virus (HIV) transmission, infant age at first positive HIV culture, and CD8+ lymphocyte activation were examined for 74 perinatally infected infants. Nineteen of the infected infants had positive HIV cultures at < or =7 days of life, and 55 had negative HIV cultures at < or =7 days but were positive later. Of the infants with early positive HIV-1 cultures, 15 of the 17 tested with DNA polymerase chain reaction methods had concordant results. The percentage of CD8+ and HLA-DR+ lymphocytes (CD8+DR+%) during the first week of life was significantly higher in infants with early compared with late positive cultures (median CD8+DR+% of 5.0% versus 2.0%, p = 0.0006). The CD8+DR+% was similar between uninfected infants and infants with late positive cultures during the first week of life (median 2%) but increased in infants with late positive cultures to 6% by 1 month. The CD4+% during the first 6 months of life was not different between infants with early or with late positive cultures, but infants with the highest CD8+DR+% at < or =7 days of life had significantly lower CD4+% at < or =7 days and at 1, 2, and 4 months of age. These data show that early CD8+ lymphocyte activation is associated with early positive HIV cultures and lower CD4+ percentages during early infancy and are consistent with the hypothesis that early positive cultures positivity may indicate in utero HIV infection.

Immune complex-dissociated p24 antigen in congenital or perinatal HIV infection: role in the diagnosis and assessment of risk of infection in infants

Immune complex-dissociated (ICD) HIV-1 p24 antigen assay is a rapid technique for assessing the presence of HIV gag or core protein in plasma or serum. In this study, ICD p24 antigen detection in HIV-1 infected mothers and their infants enrolled in the Women and Infants Transmission Study (WITS) was evaluated primarily as a diagnostic assay for HIV-1 detection in young infants and for its association with perinatal transmission. Plasma from 47 infected infants and 160 uninfected infants was examined, along with plasma from 197 of their mothers who had a delivery or close-to-delivery specimen. ICD p24 antigen was detected in plasma of 27.3% of infected infants at birth and in 70% to 81% at 1 to 6 months. The diagnostic specificity at birth was 90% and 98% to 100.0% at 1 to 6 months. The ICD p24 antigen concentration correlated with concurrent quantitative HIV culture results. The risk of transmission from mother to infant was higher if the mother had detectable ICD p24 antigen at or near the time of delivery (p = 0.002), but its presence did not accurately predict transmission (positive predictive value of 36%, negative predictive values of 85%). The relative ease of performing the ICD p24 antigen assay and the low cost compared with that of HIV culture or DNA PCR makes this test a useful adjunct for the diagnosis of perinatal HIV infection and for enhancing understanding of its pathogenesis, particularly where cost and availability limit access to more sensitive assays.

HIV-1 RNA detection in plasma for the diagnosis of infection in neonates. The French Pediatric HIV Infection Study Group

The objective of this study was to assess the frequency of detection of HIV-1 RNA in plasma of neonates born to HIV-1-seropositive mothers and to determine the diagnostic value of this method in the neonatal period. The study involved 96 infants among those enrolled in the French National Prospective Study. HIV-1 RNA was detected in the first 10 days of life by nucleic acid sequence-based amplification (NASBA) in 12 of 48 plasma samples of infected infants and in 39 of 39 of the second samples taken before the age of 3 months. On the same samples, peripheral blood mononuclear cell (PBMC) DNA polymerase chain reaction (PCR) or viral culture that had been routinely performed were found to be positive in 11 of 48 samples taken in the first 10 days of life and 39 of 39 second samples. For the noninfected infants, HIV-1 RNA was never detected in the 48 samples taken in the first 10 days of life and was detected in one of the 48 samples taken before the age of 3 months. HIV-1 RNA detection in plasma by NASBA has sensitivity and specificity equal to those of DNA PCR and culture on PBMC for the diagnosis of infection in infants with the clade B virus. This standardized method gives rapid results on a small volume of plasma and seems well suited for diagnosis on a large scale.

Interaction between timing of perinatal human immunodeficiency virus infection and the design of preventive and therapeutic interventions

In 1994, the hypothesis that transmission of human immunodeficiency virus (HIV) from mother to child could be interrupted became a reality when it was shown that a regimen of zidovudine given to HIV-infected pregnant women and their newborn infants could reduce the risk of perinatal transmission by two-thirds. An understanding of the pathogenesis of transmission is crucial for interpreting these results, for design of future interventions and for understanding the natural history of perinatal HIV infection. This paper will review current information regarding the timing of and risk factors for perinatal HIV transmission, and the relationship between the timing of transmission and design of efforts to interrupt transmission and to slow disease progression in infected infants.

Viral load and disease progression in infants infected with human immunodeficiency virus type 1. Women and Infants Transmission Study Group

BACKGROUND

There are only limited data on human immunodeficiency virus type 1 (HIV-1) RNA in perinatally infected infants. Understanding the dynamics of HIV-1 infection and its relation to disease progression may help identify opportunities for effective antiviral treatment in infected infants.

METHODS

We obtained plasma samples from 106 HIV-infected infants at birth; at 1, 2, 4, 6, 9, 12, 15, and 18 months of age; and subsequently every 6 months. HIV-1 RNA was assayed by means of a reverse-transcription polymerase chain reaction. The infants were born between 1990 and 1993, and only 21 percent of the infants' mothers received any treatment with zidovudine during pregnancy.

RESULTS

Plasma HIV-1 RNA levels increased rapidly after birth, peaked at 1 to 2 months of age (median values at 1 and 2 months, 318,000 and 256,000 copies per milliliter, respectively), and then slowly declined to a median of 34,000 copies per milliliter at 24 months. Newborns with a first positive HIV-1 culture within 48 hours after birth had significantly higher HIV-1 RNA levels, although only during the first two months of life, than those with a first positive culture seven or more days after birth. Infants with a rapid progression of disease had higher peak HIV-1 RNA levels in the first two months of life than those without rapid progression (median value, 724,000 vs. 219,000 copies per milliliter; P=0.006), as well as a higher geometric mean value during the first year of life (median value, 330,000 vs. 158,000 copies per milliliter, P=0.001).

CONCLUSIONS

In perinatally infected infants, HIV-1 RNA levels are high and decline only slowly during the first two years of life. Infants with very high viral loads in the first months of life are at increased risk for a rapid progression of disease, which suggests that early treatment with antiretroviral agents may be indicated for these infants.

Function and phenotype of immature CD4+ lymphocytes in healthy infants and early lymphocyte activation in uninfected infants of human immunodeficiency virus-infected mothers

The function and phenotypes of CD4+ lymphocytes in infants are different than in adults and are modulated by maturational changes and exposure to environmental antigens. Infants of non-human immunodeficiency virus (HIV)-infected mothers and uninfected infants of HIV-infected mothers, 0 to 6 months of age, were examined for CD4+ lymphocyte function by in vitro interleukin-2 (IL-2) production and for CD4+ phenotypes by three-color flow cytometry. A minority of these uninfected infants (28%) had functional responses similar to those of healthy adult women (IL-2 production in response to anti-CD3, alloantigen, and mitogen), while the remainder were capable of responding to alloantigen and mitogen but not to anti-CD3. We did demonstrate reduced phytohemagglutinin-stimulated IL-2 production in uninfected infants born to HIV-seropositive mothers compared to that in infants from seronegative mothers. The proportions of CD3+ CD4+, CD4+ HLA-DR- CD38+, and CD4+ CD45RA+ RO- (naive) lymphocytes were much higher in infants than in adults, and the proportions of CD4+ CD45RA- RO+ (memory) and CD4+ CD25+ (IL-2 receptor-bearing) lymphocytes were lower in infants than in adults. The proportions of activated (CD4+ HLA-DR+ CD38+) and memory (CD4+ CD45RA- RO+) lymphocytes were increased in uninfected infants of HIV-infected mothers compared to infants of uninfected mothers. Therefore, T-helper-cell function is immature in many infants, but the CD4+ lymphocytes of some HIV-exposed, uninfected infants have been stimulated by antigen at an early age.

Diagnosis of infection with human immunodeficiency virus type 1 by a DNA polymerase chain reaction assay among infants enrolled in the Women and Infants' Transmission Study

Early diagnosis of infection with human immunodeficiency virus type 1 (HIV- 1) in young infants is essential to decisions on their medical and social care. Whereas studies have suggested that polymerase chain reaction (PCR) is a sensitive and timely method of diagnosing HIV infection in children, these evaluations have been limited by the number of specimens studied. Recently, Roche Molecular Systems developed a complete HIV-1 DNA PCR testing kit (from specimen preparation to detection). In this study, use of this PCR test kit was evaluated for the detection of HIV infection in infants of seropositive mothers who were enrolled in the longitudinal, multicenter Women and Infants' Transmission Study. A total of 1209 blood specimens from 483 infants were tested and analyzed. The overall sensitivity and specificity of a single PCR test in determining HIV infection status in infants more than 1 but less than 36 months of age were 95% and 97%, respectively. For infected infants 1 to 6 months of age the sensitivity of the DNA-PCR test was 90% to 100%. In a direct comparison with coculture, the Roche DNA-PCR test was significantly more sensitive than coculture in the detection of HIV-1 in infected infants and was equivalent to coculture for the diagnosis of HIV in infants when a standardized algorithm was used to define infection status.