Impact of Human Immunodeficiency Virus and Peripartum Period on Mycobacterium tuberculosis Infection Detection.

BACKGROUND: Pregnancy and human immunodeficiency virus (HIV) may influence tuberculosis infection detection using interferon (IFN)-γ release assay (QFT-Plus; Qiagen) and tuberculin skin test (TST). METHODS: Participants in Western Kenya underwent QFT-Plus and TST in pregnancy, 6 weeks postpartum (6wkPP) and 12 months postpartum (12moPP). RESULTS: 400 participants (200 with HIV [WHIV], 200 HIV-negative) enrolled during pregnancy (median 28 weeks' gestation [interquartile range, 24-30]). QFT-Plus positivity prevalence was higher than TST in pregnancy (32.5% vs 11.6%) and through 12moPP (6wkPP, 30.9% for QFT-Plus vs 18.0% for TST; 12moPP, 29.5% vs 17.1%; all P < .001), driven primarily by QFT-Plus-positive/TST-negative discordance among HIV-negative women. Tuberculosis infection test conversion incidence was 28.4/100 person-years (PY) and higher in WHIV than HIV-negative women (35.5 vs 20.9/100 PY; hazard ratio, 1.73 [95% confidence interval, 1.04-2.88]), mostly owing to early postpartum TST conversion among WHIV. Among QFT-Plus-positive participants in pregnancy, Mycobacterium tuberculosis  (Mtb)-specific IFN-γ responses were dynamic through 12moPP and lower among WHIV than HIV-negative women with tuberculosis infection at all time points. CONCLUSIONS: QFT-Plus had higher diagnostic yield than TST in peripartum women. Peripartum QFT-Plus positivity was stable and less influenced by HIV than TST. Mtb-specific IFN-γ responses were dynamic and lower among WHIV. Tuberculosis infection test conversion incidence was high between pregnancy and early postpartum, potentially owing to postpartum immune recovery.

A scoping review of lung function in children and adolescents living with HIV in the era of antiretroviral treatment.

BACKGROUND: Human immunodeficiency virus (HIV) in children and adolescents remains an important health challenge in many countries and is commonly associated with lung disease. The introduction of antiretroviral therapy (ART) has greatly improved survival but chronic lung disease is a common ongoing challenge. We conducted a scoping review of studies that have reported lung function in school-aged children and adolescents living with HIV. METHODS: A systematic literature search was performed by searching Medline, Embase, and PubMed databases, limited to articles published between 2011 and 2021 in English language. Inclusion criteria were studies involving participants living with HIV aged 5-18 years and having spirometry data. The primary outcome was lung function as measured by spirometry. RESULTS: Twenty-one studies were included in the review. Most study participants were living in the sub-Saharan African region. The prevalence of reduced forced expiratory volume in 1 s (FEV1 ) ranged from 25.3% to 73% across studies, reduced forced vital capacity (FVC) ranged from 10% to 42% and reduced FEV1 /FVC ranged from 3% to 26%. The mean z-score of FEV1 ranged from -2.19 to -0.73, mean zFEV1 /FVC ranged from -0.74 to 0.2, and mean FVC ranged from -1.86 to -0.63. CONCLUSION: There is a high prevalence of lung function impairment in children and adolescents living with HIV, which persists in the ART era. Further studies are needed of interventions that might improve lung function in these vulnerable populations.

Early Antiretroviral Therapy Reduces Severity but Does Not Eliminate Neurodevelopmental Compromise in Children With HIV.

BACKGROUND: Early antiretroviral therapy (ART) during infancy reduces cognitive impairment due to HIV, but the extent of benefit is unclear. SETTING: Children were recruited from hospital and health centers providing HIV care and treatment in Nairobi, Kenya. METHODS: Cognitive, behavioral, and motor outcomes were assessed in children with HIV and early ART (<1 year), children with HIV and late ART (1.5-6 years), and children HIV-unexposed uninfected (CHUU). Domain z scores and odds neurobehavioral impairment (≤15th percentile in CHUU) were compared in adjusted analyses. RESULTS: Children with HIV initiated ART at median ages 0.4 (early ART) and 3.5 years (late ART). Children were assessed at median ages 6.9 (CHUU, N = 61), 6.9 (early ART, N = 54), and 13.5 (late ART; N = 27) years. Children with late ART vs. children with early ART had significantly lower z scores in 7 domains, specifically global cognition, short-term memory, visuospatial processing, learning, nonverbal test performance, executive function, and motor skills (adjusted mean differences, -0.42 to -0.62, P values ≤ 0.05), and had higher odds impairment in 7 domains (adjusted odds ratios [aORs], 2.87 to 16.22, P values ≤ 0.05). Children with early ART vs. CHUU had lower z scores in 5 domains (global cognition, short-term memory, delayed memory, processing speed, and behavioral regulation [adjusted mean differences, -0.32 to -0.88, P values < 0.05]) and higher impairment for 2 domains (short-term memory [aOR, 3.88] and behavioral regulation [aOR 3.46], P values < 0.05). Children with late ART vs. CHUU had lower z scores in 8 domains (adjusted mean differences, -0.57 to -1.05, P values ≤ 0.05), and higher impairment in 7 domains (aORs 1.98 to 2.32, P values ≤ 0.05). CONCLUSION: Early ART in the first year of life attenuates but does not eliminate the neurodevelopmental compromise of HIV.

Brief Report: Performance of Tuberculosis Symptom Screening Among Hospitalized ART-Naive Children With HIV in Kenya.

BACKGROUND: The World Health Organization (WHO) recommends tuberculosis (TB) diagnostic evaluation for children with HIV (CHIV) who have history of TB contact, poor weight gain, cough, or fever. These screening criteria were developed based on studies of symptomatic CHIV with incomplete microbiologic confirmation. We performed routine TB microbiologic evaluation of hospitalized CHIV with and without symptoms to develop a data-driven TB symptom screen. METHODS: Among hospitalized antiretroviral therapy-naive Kenyan CHIV enrolled in the Pediatric Urgent Start of Highly Active Antiretroviral Therapy (PUSH) trial, we performed Xpert MTB/RIF and mycobacterial culture of respiratory and stool specimens independent of TB symptoms. We evaluated performance of WHO and other published pediatric TB screening criteria and derived optimized criteria using a combination of symptoms. RESULTS: Of 168 CHIV who underwent TB microbiologic evaluation, 13 (8%) had confirmed TB. WHO TB symptom screening had 100% sensitivity and 4% specificity to detect confirmed TB. Published TB screening criteria that relied on prolonged symptoms missed cases of confirmed TB (sensitivity 85%-92%). An optimized symptom screen including weight loss, cough, anorexia, or TB contact had 100% sensitivity and improved specificity (31%) compared with the WHO pediatric TB symptom screen. CONCLUSIONS: The WHO TB symptom screen was highly sensitive but resulted in a high proportion of hospitalized CHIV who would require TB diagnostic evaluation. Other published TB screening criteria missed CHIV with confirmed TB. Our optimized screening tool increased specificity while preserving sensitivity. Future multicenter studies are needed to improve TB screening tools for CHIV in both inpatient and outpatient settings.

A CD4+ TNF+ monofunctional memory T-cell response to BCG vaccination is associated with Mycobacterium tuberculosis infection in infants exposed to HIV.

BACKGROUND: The immunologic correlates of risk of Mycobacterium tuberculosis (Mtb) infection after BCG vaccination are unknown. The mechanism by which BCG influences the tuberculin skin test (TST) remains poorly understood. We evaluated CD4+ T-cell responses in infants exposed to HIV and uninfected (HEU) who received BCG at birth and examined their role in susceptibility to Mtb infection and influence on TST induration. METHODS: HEU infants were enrolled in a randomised clinical trial of isoniazid (INH) to prevent Mtb infection in Kenya. We measured mycobacterial antigen-specific Th1 and Th17 cytokine responses at 6-10 weeks of age prior to INH randomisation and compared responses between Mtb infected and uninfected infants. Outcomes at 14 months of age included TST, QuantiFERON-Plus (QFT-Plus), and ESAT-6/CFP-10-specific non-IFN-γ cytokines measured in QFT-Plus supernatants. FINDINGS: A monofunctional mycobacterial antigen-specific TNF+ CD4+ effector memory (CCR7-CD45RA-) T-cell response at 6-10 weeks of age was associated with Mtb infection at 14 months of age as measured by ESAT-6/CFP-10-specific IFN-γ and non-IFN-γ responses (Odds Ratio 2.26; Confidence Interval 1.27-4.15; P = 0.006). Mycobacterial antigen-specific polyfunctional effector memory Th1 responses at 6-10 weeks positively correlated with TST induration in infants without evidence of Mtb infection at 14 months, an association which was diminished by INH therapy. INTERPRETATION: Induction of monofunctional TNF+ CD4+ effector memory T-cell responses may be detrimental in TB vaccine development. This study also provides mechanistic insight into the association of BCG-induced immune responses with TST induration and further evidence that TST-based diagnoses of Mtb infection in infants are imprecise. FUNDING: Thrasher Research Fund.

Cumulative Mycobacterium tuberculosis Infection Incidence (Measured Primarily by Tuberculin Skin Test) Among Infants With Human Immunodeficiency Virus Exposure: Observational Follow-up of an Isoniazid Prophylaxis Trial.

Cumulative 24-month Mycobacterium tuberculosis infection incidence (measured primarily by tuberculin skin test [TST]) was high among human immunodeficiency virus exposed but uninfected infants (8.7 [95% confidence interval, 6.3-11.9] per 100 person-years). Trend for decreased TST positivity among infants at trial end (12 months postenrollment) randomized to isoniazid at 6 weeks of age was not sustained through observational follow-up to 24 months of age. CLINICAL TRIALS REGISTRATION: NCT02613169.

Cytomegalovirus Viremia and Clinical Outcomes in Kenyan Children Diagnosed With Human Immunodeficiency Virus (HIV) in Hospital.

BACKGROUND: Cytomegalovirus (CMV) viremia is common in human immunodeficiency virus (HIV) infection and is associated with worse long-term outcomes. To date, no studies have assessed CMV viremia in children diagnosed with HIV in hospital. METHODS: We studied CMV viremia and clinical outcomes in 163 Kenyan children aged 2 months to 12 years, diagnosed with HIV in hospital. CMV DNA levels in plasma were measured using quantitative polymerase chain reaction (PCR). Regression models were used to assess associations between CMV viremia ≥1000 IU/mL and the risk of continued hospitalization or death at 15 days, duration of hospitalization, and 6-month mortality. RESULTS: At enrollment, 62/114 (54%) children had CMV viremia, and 20 (32%) were ≥1000 IU/mL. Eleven CMV reactivations were observed after admission. The prevalence and level of CMV viremia were highest in children <2 years and lowest in children ≥5 years old. CMV viremia ≥1000 IU/mL was independently associated with age <2 years (P = .03), higher log10 HIV RNA level (P = .01), and height-for-age z score >-2 (P = .02). Adjusting for age and log10 HIV RNA, the relative risk of death or continued hospitalization at 15 days was 1.74 (95% confidence interval [CI] = 1.04, 2.90), and the hazard ratio of 6-month mortality was 1.97 (95% CI = .57, 5.07) for children with CMV DNA ≥1000 IU/mL compared to lower-level or undetectable CMV DNA. Children with CMV DNA ≥1000 IU/mL were hospitalized a median ~5 days longer than children with lower-level or undetectable CMV DNA (P = .002). CONCLUSIONS: In this nested observational study, CMV viremia was common in hospitalized children with HIV, and levels ≥1000 IU/mL were associated with increased risk of mortality and longer hospitalization.

A Randomized Controlled Trial of Isoniazid to Prevent Mycobacterium tuberculosis Infection in Kenyan Human Immunodeficiency Virus-Exposed Uninfected Infants.

BACKGROUND: Human immunodeficiency virus (HIV)-exposed uninfected (HEU) infants in endemic settings are at high risk of tuberculosis (TB). For infants, progression from primary Mycobacterium tuberculosis (Mtb) infection to TB disease can be rapid. We assessed whether isoniazid (INH) prevents primary Mtb infection. METHODS: We conducted a randomized nonblinded controlled trial enrolling HEU infants 6 weeks of age without known TB exposure in Kenya. Participants were randomized (1:1) to 12 months of daily INH (10 mg/kg) vs no INH. Primary endpoint was Mtb infection at end of 12 months, assessed by interferon-γ release assay (QuantiFERON-TB Gold Plus) and/or tuberculin skin test (TST, added 6 months after first participant exit). RESULTS: Between 15 August 2016 and 6 June 2018, 416 infants were screened, with 300 (72%) randomized to INH or no INH (150 per arm); 2 were excluded due to HIV infection. Among 298 randomized HEU infants, 12-month retention was 96.3% (287/298), and 88.9% (265/298) had primary outcome data. Mtb infection prevalence at 12-month follow-up was 10.6% (28/265); 7.6% (10/132) in the INH arm and 13.5% (18/133) in the no INH arm (7.0 vs 13.4 per 100 person-years; hazard ratio, 0.53 [95% confidence interval {CI}, .24-1.14]; P = .11]), and driven primarily by TST positivity (8.6% [8/93] in INH and 18.1% [17/94] in no INH; relative risk, 0.48 [95% CI, .22-1.05]; P = .07). Frequency of severe adverse events was similar between arms (INH, 14.0% [21/150] vs no INH, 10.7% [16/150]; P = .38), with no INH-related adverse events. CONCLUSIONS: Further studies evaluating TB preventive therapy to prevent or delay primary Mtb infection in HEU and other high-risk infants are warranted. CLINICAL TRIALS REGISTRATION: NCT02613169.

Infant TB Infection Prevention Study (iTIPS): a randomised trial protocol evaluating isoniazid to prevent M. tuberculosis infection in HIV-exposed uninfected children.

INTRODUCTION: HIV-exposed uninfected (HEU) infants in tuberculosis (TB) endemic settings are at high risk of Mycobacterium tuberculosis (Mtb) infection and TB disease, even in the absence of known Mtb exposure. Because infancy is a time of rapid progression from primary infection to active TB disease, it is important to define when and how TB preventive interventions exert their effect in order to develop effective prevention strategies in this high-risk population. METHODS AND ANALYSIS: We designed a non-blinded randomised controlled trial to determine efficacy of isoniazid (INH) to prevent primary Mtb infection among HEU children. Target sample size is 300 (150 infants in each arm). Children are enrolled at 6 weeks of age from maternal and child health clinics in Kenya and are randomised to receive 12 months of daily INH ~10 mg/kg plus pyridoxine or no INH. The primary endpoint is Mtb infection, assessed by interferon-gamma release assay QuantiFERON-TB Gold Plus (QFT-Plus) or tuberculin skin test after 12 months post-enrolment. Secondary outcomes include severe adverse events, expanded Mtb infection definition using additional QFT-Plus supernatant markers and determining correlates of Mtb infection. Exploratory analyses include a combined outcome of TB infection, disease and mortality, and sensitivity analyses excluding infants with baseline TB-specific responses on flow cytometry. ETHICS AND DISSEMINATION: An external and independent Data and Safety Monitoring Board monitors adverse events. Results will be disseminated through peer-reviewed journals, presentations at local and international conferences to national and global policy-makers, the local community and participants. TRIAL REGISTRATION NUMBER: NCT02613169; Pre-results.

Financial Incentives to Increase Uptake of Pediatric HIV Testing (FIT): study protocol for a randomised controlled trial in Kenya.

INTRODUCTION: Index case testing (ICT) to identify HIV-infected children is efficient but has suboptimal uptake. Financial incentives (FI) have overcome financial barriers in other populations by offsetting direct and indirect costs. A pilot study found FI to be feasible for motivating paediatric ICT among HIV-infected female caregivers. This randomised trial will determine the effectiveness of FI to increase uptake of paediatric ICT. METHODS AND ANALYSIS: The Financial Incentives to Increase Uptake of Pediatric HIV Testing trial is a five-arm, unblinded, randomised controlled trial that determines whether FI increases timely uptake of paediatric ICT. The trial will be conducted in multiple public health facilities in western Kenya. Each HIV-infected adult enrolled in HIV care will be screened for eligibility: primary caregiver to one or more children of unknown HIV status aged 0-12 years. Eligible caregivers will be individually randomised at the time of recruitment in equal 1:1:1:1:1 allocation to one of five arms (US$0 (control), US$1.25, US$2.50, US$5.00 and US$10.00). The trial aims to randomise 800 caregivers. Incentives will be disbursed at the time of child HIV testing using mobile money transfer or cash. Arms will be compared in terms of the proportion of adults who complete testing for at least one child within 2 months of randomisation and time to testing. A cost-effectiveness analysis of FI for paediatric ICT will also be conducted. ETHICS AND DISSEMINATION: This study was reviewed and approved by the University of Washington Institutional Review Board and the Kenyatta National Hospital Ethics and Research Committee. Trial results will be disseminated to healthcare workers at study sites, regional and national policymakers, and with patient populations at study sites (regardless of enrolment in the trial). Randomised trials of caregiver-child FI interventions pose unique study design, ethical and operational challenges, detailed here as a resource for future investigations. TRIAL REGISTRATION NUMBER: NCT03049917; Pre-results.

Adolescent age is an independent risk factor for abnormal spirometry among people living with HIV in Kenya.

OBJECTIVES: As life expectancy of people living with HIV (PLWH) improves in low-income and middle-income countries (LMICs), the spectrum of HIV-related pulmonary complications may reflect a greater burden of chronic lung diseases as in high-income countries. We determined whether the risk of abnormal spirometry was greater among adolescent compared with adult PLWH at the Coptic Hope Center for Infectious Diseases in Nairobi, Kenya, and evaluated the role of other cofactors for abnormal spirometry. DESIGN: We prospectively enrolled adolescent and adult PLWH for this cross-sectional study. METHODS: Data collection included standardized questionnaires, clinical assessment, and prebronchodilator and postbronchodilator spirometry. Adolescents additionally underwent noncontrast chest computed tomography. Multivariable logistic regression determined associations of adolescent age with abnormal spirometry, adjusting for cofactors. RESULTS: Of 427 PLWH, 21 (40%) adolescents and 64 (17%) adults had abnormal spirometry. Among adolescents, 80% had abnormal chest CTs, and 79% had at least one respiratory symptom. Adolescent age (adjusted odds ratio 3.22; 95% confidence interval 1.48-6.98) was independently associated with abnormal spirometry, adjusting for recent CD4, HIV clinical stage, low BMI, indoor kerosene use, smoking pack-years, and prior pulmonary tuberculosis. Additional important cofactors for abnormal spirometry included prior pulmonary tuberculosis (3.15; 1.70-5.58), kerosene use (1.77; 1.04-3.04) and smoking pack-years (1.05; 1.00-1.10). Adolescent age, prior pulmonary tuberculosis, and smoking pack-years were significantly associated with airflow limitation. CONCLUSION: Adolescent age was independently associated with increased risk of abnormal spirometry, particularly airflow limitation. Studies to improve prevention, detection, and management of chronic lung disease across the lifespan among PLWH are needed in LMICs.

Financial Incentives for Pediatric HIV Testing in Kenya.

The acceptability of financial incentives for pediatric HIV testing was evaluated in Kenya. Sixty HIV-positive women with children of unknown status were randomized to receive $5, $10 or $15 conditional upon HIV testing. Forty-four (73%) completed child testing, with similar rates across arms. Uptake was significantly higher than a cohort with similar procedures but no incentives (73% vs. 14%, P < 0.001).

Implementation and Operational Research: Active Referral of Children of HIV-Positive Adults Reveals High Prevalence of Undiagnosed HIV.

OBJECTIVES: Few routine systems exist to test older, asymptomatic children for HIV. Testing all children in the population has high uptake but is inefficient, whereas testing only symptomatic children increases efficiency but misses opportunities to optimize outcomes. Testing children of HIV-infected adults in care may efficiently identify previously undiagnosed HIV-infected children before symptomatic disease. METHODS: HIV-infected parents in HIV care in Nairobi, Kenya were systematically asked about their children's HIV status and testing history. Adults with untested children ≤12 years old were actively referred and offered the choice of pediatric HIV testing at home or clinic. Testing uptake and HIV prevalence were determined, as were bottlenecks in pediatric HIV testing cascade. RESULTS: Of 10,426 HIV-infected adults interviewed, 8,287 reported having children, of whom 3,477 (42%) had children of unknown HIV status, and 611 (7%) had children ≤12 years of unknown HIV status. After implementation of active referral, the rate of pediatric HIV testing increased 3.8-fold from 3.5 to 13.6 children tested per month (Relative risk: 3.8, 95% confidence interval: 2.3 to 6.1). Of 611 eligible adults, 279 (48%) accepted referral and were screened, and 74 (14%) adults completed testing of 1 or more children. HIV prevalence among 108 tested children was 7.4% (95% confidence interval: 3.3 to 14.1%) and median age was 8 years (interquartile range: 2-11); 1 child was symptomatic at testing. CONCLUSIONS: Referring HIV-infected parents in care to have their children tested revealed many untested children and significantly increased the rate of pediatric testing; prevalence of HIV was high. However, despite increases in pediatric testing, most adults did not complete testing of their children.

Hospitalized Children Reveal Health Systems Gaps in the Mother-Child HIV Care Cascade in Kenya.

To identify missed opportunities in HIV prevention, diagnosis, and linkage to care, we enrolled 183 hospitalized, HIV-infected, ART-naïve Kenyan children 0-12 years from four hospitals in Nairobi and Kisumu, and reviewed prevention of mother-to-child transmission of HIV (PMTCT), hospitalization, and HIV testing history. Median age was 1.8 years (IQR = 0.8, 4.5). Most mothers received HIV testing during pregnancy (77%). Among mothers tested, 60% and 40% reported HIV-negative and positive results, respectively; 33% of HIV-diagnosed mothers did not receive PMTCT antiretrovirals. First missed opportunities for pediatric diagnosis and linkage were due to failure to test mothers (23.1%), maternal HIV acquisition following initial negative test (45.7%), no early infant diagnosis (EID) or provider-initiated testing (PITC) (12.7%), late breastfeeding transmission (8.7%), failure to collect child HIV test results (1.2%), and no linkage to care following HIV diagnosis (8.7%). Among previously hospitalized children, 38% never received an HIV test. Strengthening initial and repeat maternal HIV testing and PITC are key interventions to prevent, detect, and treat pediatric HIV infections.

Clinical and virologic manifestations of primary Epstein-Barr virus (EBV) infection in Kenyan infants born to HIV-infected women.

BACKGROUND: Human immunodeficiency virus (HIV) infection is a risk factor for Epstein-Barr virus (EBV)-associated lymphomas. Characterizing primary infection may elucidate risk factors for malignancy. METHODS: To describe clinical and virologic manifestations of primary EBV infection among infants born to HIV-infected women, specimens were utilized from a cohort study conducted in Nairobi, Kenya. HIV and EBV viral loads were measured serially in plasma. EBV serology was performed on EBV DNA-negative infants. Monthly clinical examinations were performed by pediatricians. RESULTS: The probability of EBV infection by 1 year of age was .78 (95% CI, .67-.88) in HIV-infected and .49 (95% CI, .35-.65) in HIV-uninfected infants (P < .0001). At 2 years, probability of EBV infection was .96 (95% CI, .89-.99) in HIV-infected infants. Peak EBV loads were higher in HIV-infected versus HIV-uninfected infants (median 2.6 vs 2.1 log10 copies/mL; P < .0001). The majority of HIV-infected infants had detectable EBV DNA for >3 months (79%). Primary EBV infection was associated with cough, fever, otitis media, pneumonia, hepatomegaly, splenomegaly, and hospitalization in HIV-infected infants; conjunctivitis and rhinorrhea in HIV-uninfected infants. CONCLUSIONS: EBV infection occurs early in infants born to HIV-infected women. HIV infection was associated with more frequent and higher quantity EBV DNA detection.

Performance of the integrated management of childhood illness algorithm for diagnosis of HIV-1 infection among African infants.

OBJECTIVES: Early infant HIV-1 diagnosis and treatment substantially improve survival. Where virologic HIV-1 testing is unavailable, integrated management of childhood illness (IMCI) clinical algorithms may be used for infant HIV-1 screening. We evaluated the performance of the 2008 WHO IMCI HIV algorithm in a cohort of HIV-exposed Kenyan infants. METHODS: From 1999 to 2003, 444 infants had monthly clinical assessments and quarterly virologic HIV-1 testing. Using archived clinical data, IMCI sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using virologic testing as a gold standard. Linear regression and survival analyses were used to determine the effect of age on IMCI performance and timing of diagnosis. RESULTS: Overall IMCI sensitivity, specificity, PPV, and NPV value were 58, 87, 52, and 90%, respectively. Sensitivity (1.4%) and PPV (14%) were lowest at 1 month of age, when 81% of HIV infections already had occurred. Sensitivity increased with age (P < 0.0001), but remained low throughout infancy (range 1.4-35%). Specificity (range 97-100%) was high at each time point and was not associated with age. Fifty-eight percent of HIV-1-infected infants (50 of 86) were eventually diagnosed by IMCI, and use of IMCI was estimated to delay diagnosis in HIV-infected infants by a median of 5.9 months (P < 0.0001). CONCLUSION: IMCI had low sensitivity during the first month of life, when the majority of HIV-1 infections had already occurred and initiation of treatment is most critical. Although sensitivity increased with age, the substantial delay in HIV-1 diagnosis using IMCI limits its utility in early infant HIV-1 diagnosis.

Phenotypic characterization of HIV-specific CD8+ T cells during early and chronic infant HIV-1 infection.

Although CD8(+) T cells play an important role in the containment of adult HIV-1 replication, their role in infant HIV-1 infection is not as well understood. Impaired HIV-specific CD8(+) T cell responses may underlie the persistently high viral loads observed in infants. We examined the frequency and phenotype of infant HIV-specific CD8(+) T cells in 7 HIV-infected antiretroviral therapy-naïve infants during the first 2 years of life, using class I HLA tetramers and IFN-γ-ELISPOT. The frequency (0.088-3.9% of CD3(+)CD8(+) cells) and phenotype (CD27(+)CD28(-), CD45RA(+/-), CD57(+/-), HLA-DR(+), CD95(+)) of infant HIV-specific CD8(+) T cells were similar to reports in adults undergoing early infection. Unlike adults, at 23-24 months post-infection a high frequency of HIV-specific CD8(+) T cells expressed HLA-DR (mean 80%, range 68-85%) and CD95 (mean 88%, range 79-96%), suggesting sustained activation and vulnerability to apoptosis. Despite comparable expansion of HIV-specific CD8(+) T cells of a similar phenotype to adults during early infection, infant T cells failed to contain HIV-1 replication, and remained persistently activated and vulnerable to apoptosis during chronic infection.