HIV disease and respiratory infection in children

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.

Exploring the Associations between Early Childhood Development Outcomes and Ecological Country-Level Factors across Low- and Middle-Income Countries

A poor start in life shapes children's development over the life-course. Children from low- and middle-income countries (LMICs) are exposed to low levels of early stimulation, greater socioeconomic deprivation and persistent environmental and health challenges. Nevertheless, little is known about country-specific factors affecting early childhood development (ECD) in LMICs. Using data from 68 LMICs collected as part of the Multiple Indicator Cluster Surveys between 2010 and 2018, along with other publicly available data sources, we employed a multivariate linear regression analysis at a national level to assess the association between the average Early Childhood Development Index (ECDI) in children aged 3-5 and country-level ecological characteristics: early learning and nurturing care and socioeconomic and health indicators. Our results show that upper-middle-income country status, attendance at early childhood education (ECE) programs and the availability of books at home are positively associated with a higher ECDI. Conversely, the prevalence of low birthweight and high under-5 and maternal mortality are negatively associated with ECDI nationally. On average, LMICs with inadequate stimulation at home, higher mortality rates and without mandatory ECE programs are at greater risks of poorer ECDI. Investment in early-year interventions to improve nurturing care and ECD outcomes is essential for achieving Sustainable Development Goals.

Risk factors for death among children aged 5-14 years hospitalised with pneumonia: a retrospective cohort study in Kenya

INTRODUCTION

There were almost 1 million deaths in children aged between 5 and 14 years in 2017, and pneumonia accounted for 11%. However, there are no validated guidelines for pneumonia management in older children and data to support their development are limited. We sought to understand risk factors for mortality among children aged 5-14 years hospitalised with pneumonia in district-level health facilities in Kenya.

METHODS

We did a retrospective cohort study using data collected from an established clinical information network of 13 hospitals. We reviewed records for children aged 5-14 years admitted with pneumonia between 1 March 2014 and 28 February 2018. Individual clinical signs were examined for association with inpatient mortality using logistic regression. We used existing WHO criteria (intended for under 5s) to define levels of severity and examined their performance in identifying those at increased risk of death.

RESULTS

1832 children were diagnosed with pneumonia and 145 (7.9%) died. Severe pallor was strongly associated with mortality (adjusted OR (aOR) 8.06, 95% CI 4.72 to 13.75) as were reduced consciousness, mild/moderate pallor, central cyanosis and older age (>9 years) (aOR >2). Comorbidities HIV and severe acute malnutrition were also associated with death (aOR 2.31, 95% CI 1.39 to 3.84 and aOR 1.89, 95% CI 1.12 to 3.21, respectively). The presence of clinical characteristics used by WHO to define severe pneumonia was associated with death in univariate analysis (OR 2.69). However, this combination of clinical characteristics was poor in discriminating those at risk of death (sensitivity: 0.56, specificity: 0.68, and area under the curve: 0.62).

CONCLUSION

Children >5 years have high inpatient pneumonia mortality. These findings also suggest that the WHO criteria for classification of severity for children under 5 years do not appear to be a valid tool for risk assessment in this older age group, indicating the urgent need for evidence-based clinical guidelines for this neglected population.

The Incidence of Respiratory Tract Infections in Vertically HIV-Infected Children in Lower Silesia in Poland and the Approach to Infection Prevention

Human immunodeficiency virus (HIV) is a risk factor associated with respiratory tract infections. However little is known about the prevalence of these infections in HIV-infected children in Poland. We investigated the incidence of respiratory tract infections in 26 HIV-infected children (aged 4-18, mean 10.3 years, including 17 girls) treated in our center and compared it with the age-matched control group of 70 children. The prevalence of chronic diseases and other factors such as cigarette smoking by household members or attending educational institutions were also taken into consideration. Among the HIV-infected children, 48 respiratory infections were observed, including 4 cases of pneumonia and 44 other respiratory infections for 312 person-month observations vs. 256 infections including 13 cases of pneumonia and 243 other respiratory infections for 840 person-month observations in the control group. Thus, incidence of respiratory infections per month was lower in HIV-infected children (14%) compared with the control group (29%), i.e., 0.14 95% CI (0.10-0.18) infections per month vs. 0.29 95% CI (0.26-0.32). There was no difference in the incidence of pneumonia. The lower incidence of respiratory infections in HIV-infected children may be explained by their avoiding sick people, taking influenza vaccination on the annual basis, and possibly antiviral medication. We conclude that the influence of modifiable environmental factors that reduce the risk of respiratory tract infections is more significant than the HIV infection itself.

Reasons for hospitalization in HIV-infected children in West Africa

INTRODUCTION

Current knowledge on morbidity and mortality in HIV-infected children comes from data collected in specific research programmes, which may offer a different standard of care compared to routine care. We described hospitalization data within a large observational cohort of HIV-infected children in West Africa (IeDEA West Africa collaboration).

METHODS

We performed a six-month prospective multicentre survey from April to October 2010 in five HIV-specialized paediatric hospital wards in Ouagadougou, Accra, Cotonou, Dakar and Bamako. Baseline and follow-up data during hospitalization were recorded using a standardized clinical form, and extracted from hospitalization files and local databases. Event validation committees reviewed diagnoses within each centre. HIV-related events were defined according to the WHO definitions.

RESULTS

From April to October 2010, 155 HIV-infected children were hospitalized; median age was 3 years [1-8]. Among them, 90 (58%) were confirmed for HIV infection during their stay; 138 (89%) were already receiving cotrimoxazole prophylaxis and 64 children (40%) had initiated antiretroviral therapy (ART). The median length of stay was 13 days (IQR: 7-23); 25 children (16%) died during hospitalization and four (3%) were transferred out. The leading causes of hospitalization were WHO stage 3 opportunistic infections (37%), non-AIDS-defining events (28%), cachexia and other WHO stage 4 events (25%).

CONCLUSIONS

Overall, most causes of hospitalizations were HIV related but one hospitalization in three was caused by a non-AIDS-defining event, mostly in children on ART. HIV-related fatality is also high despite the scaling-up of access to ART in resource-limited settings.

Outcome of human immunodeficiency virus-exposed and -infected children admitted to a pediatric intensive care unit for respiratory failure

OBJECTIVE

Acute severe pneumonia with respiratory failure in human immunodeficiency virus-infected and -exposed infants carries a high mortality. Pneumocystis jiroveci is one cause, but other organisms have been suggested to play a role. Our objective is to describe the coinfections and treatment strategies in a cohort of human immunodeficiency virus-infected and -exposed infants with respiratory failure and acute respiratory distress syndrome, in an attempt to improve survival.

DESIGN

Prospective intervention study.

SETTING

Steve Biko Academic Hospital, Pretoria, South Africa.

PATIENTS

Human immunodeficiency virus-exposed infants with respiratory failure and acute respiratory distress syndrome were recruited into the study.

INTERVENTIONS

All infants were treated with routine therapy for Pneumocystis jiroveci and bacterial coinfection. However, in addition, all infants received ganciclovir from admission until the cytomegalovirus viral load result was demonstrated to be <log 4.

MEASUREMENTS

Routine investigations included human immunodeficiency virus polymerase chain reaction, cytomegalovirus viral load, blood culture, C-reactive protein, and white cell count. Tracheal aspirates for Pneumocystis jiroveci detection, bacterial culture, tuberculosis culture, and viral identification were performed.

MAIN RESULTS

Sixty-three patients met the recruitment criteria. The mortality rate was 30%. Pneumocystis jiroveci was positive in 33% of infants, while 38% had cytomegalovirus viral load ≥log 4. Only 7.9% of infants had a positive tuberculosis culture. Nineteen deaths occurred, 13 of which had a cytomegalovirus viral load ≥log 4. Bacterial coinfection and CD4 count were not predictors of mortality.

CONCLUSIONS

A case fatality rate of 30% is achievable if severe pneumonia with respiratory failure and acute respiratory distress syndrome is managed with a combination of antibiotics and ventilation strategies. Cytomegalovirus infection appears to be associated with an increased risk of death in this syndrome. This may, however, be a marker of as yet undefined pathology.

Development of the Respiratory Index of Severity in Children (RISC) score among young children with respiratory infections in South Africa

Objective

Pneumonia is a leading cause of death in children worldwide. A simple clinical score predicting the probability of death in a young child with lower respiratory tract infection (LRTI) could aid clinicians in case management and provide a standardized severity measure during epidemiologic studies.

Methods

We analyzed 4,148 LRTI hospitalizations in children <24 months enrolled in a pneumococcal conjugate vaccine trial in South Africa from 1998–2001, to develop the Respiratory Index of Severity in Children (RISC). Using clinical data at admission, a multivariable logistic regression model for mortality was developed and statistically evaluated using bootstrap resampling techniques. Points were assigned to risk factors based on their coefficients in the multivariable model. A child's RISC score is the sum of points for each risk factor present. Separate models were developed for HIV-infected and non-infected children.

Results

Significant risk factors for HIV-infected and non-infected children included low oxygen saturation, chest indrawing, wheezing, and refusal to feed. The models also included age and HIV clinical classification (for HIV-infected children) or weight-for-age (for non-infected children). RISC scores ranged up to 7 points for HIV-infected or 6 points for non-infected children and correlated with probability of death (0–47%, HIV-infected; 0–14%, non-infected). Final models showed good discrimination (area under the ROC curve) and calibration (goodness-of-fit).

Conclusion

The RISC score incorporates a simple set of risk factors that accurately discriminate between young children based on their risk of death from LRTI, and may provide an objective means to quantify severity based on the risk of mortality.

CMV pneumonia in HIV-infected ventilated infants

BACKGROUND

The contributing role of cytomegalovirus (CMV) in infants treated for Pneumocystis jiroveci pneumonia (PJP) is unknown. High dose steroids used in the treatment of PJP may further immunocompromise these infants contributing to the development of CMV pneumonia.

AIM

The aim of this study was to determine the role of CMV pneumonia in infants being ventilated for suspected PJP.

METHODS

In this prospective study HIV infected infants being treated with trimethoprim-sulfamethoxazole (TMP/SMX) and ventilated for suspected PJP were included if they had not responded to treatment. Open lung biopsy was performed if there was no improvement in ventilatory requirements.

RESULTS

Twenty-five HIV positive infants with a mean age of 3.3 months were included. Lung biopsy was performed in 17 (68%) and post-mortem lung tissue was obtained in 8 (32%). After evaluation of the histology, immunohistochemistry, and viral cultures from lung tissue, the most likely causes of pneumonia were: CMV and PJP dual infection 36% (n = 9), CMV pneumonia 36% (n = 9), and PJP 24% (n = 6). The pp65 test for CMV antigen was falsely negative in 24%. The mean blood CD4 count was 287/microl. There was an association between the CD4 lymphocyte status and the final diagnosis, with the CMV and PJP group (CD4 110/microl) having the lowest CD4 status (P = 0.0128). Pediatric Intensive Care Unit (PICU) mortality was 72% (n = 18) and in hospital mortality 88%.

CONCLUSION

Of the ventilated infants failing to respond to treatment, 72% had histologically confirmed CMV pneumonia, probably accounting for the high mortality in this cohort. The incidence of CMV disease in HIV infected infants being ventilated for severe pneumonia warrants that ganciclovir is used empirically until CMV disease is excluded. The role of lung biopsy in these circumstances needs to be researched.

Chest radiographic pulmonary changes reflecting extrapulmonary involvement in paediatric HIV disease

Respiratory infections are the commonest cause of pulmonary change on chest radiographs of HIV-infected children. However, HIV-related neurological, oropharyngeal, oesophageal, cardiac and haematological abnormalities may also manifest with pulmonary changes and must be considered in the interpretation of the chest radiograph in HIV-infected children.

Non-infective pulmonary disease in HIV-positive children

It is estimated that over 90% of children infected with human immunodeficiency virus (HIV) live in the developing world and particularly in sub-Saharan Africa. Pulmonary disease is the most common clinical feature of acquired immunodeficiency syndrome (AIDS) in infants and children causing the most morbidity and mortality, and is the primary cause of death in 50% of cases. Children with lung disease are surviving progressively longer because of earlier diagnosis and antiretroviral treatment and, therefore, thoracic manifestations have continued to change and unexpected complications are being encountered. It has been reported that 33% of HIV-positive children have chronic changes on chest radiographs by the age of 4 years. Lymphocytic interstitial pneumonitis is common in the paediatric HIV population and is responsible for 30-40% of pulmonary disease. HIV-positive children also have a higher incidence of pulmonary malignancies, including lymphoma and pulmonary Kaposi sarcoma. Immune reconstitution inflammatory syndrome is seen after highly active antiretroviral treatment. Complications of pulmonary infections, aspiration and rarely interstitial pneumonitis are also seen. This review focuses on the imaging findings of non-infective chronic pulmonary disease.

Emergence of a peak in early infant mortality due to HIV/AIDS in South Africa

OBJECTIVES

South Africa has among the highest levels of HIV prevalence in the world. Our objectives are to describe the distribution of South African infant and child mortality by age at fine resolution, to identify any trends over recent time and to examine these trends for HIV-associated and non HIV-associated causes of mortality.

METHODS

A retrospective review of vital registration data was conducted. All registered postneonatal deaths under 1 year of age in South Africa for the period 1997-2002 were analysed by age in months using a generalized linear model with a log link and Poisson family.

RESULTS

Postneonatal mortality increased each year over the period 1997-2002. A peak in HIV-related deaths was observed, centred at 2-3 months of age, rising monotonically over time.

CONCLUSION

We interpret the peak in mortality at 2-3 months as an indicator for paediatric AIDS in a South African population with high HIV prevalence and where other causes of death are not sufficiently high to mask HIV effects. Intrauterine and intrapartum infection may contribute to this peak. It is potentially a useful surveillance tool, not requiring an exact cause of death. The findings also illustrate the need for early treatment of mother and child in settings with very high HIV prevalence.

Vaccines to prevent pneumonia and improve child survival

For more than 30 years, vaccines have played an important part in pneumonia prevention. Recent advances have created opportunities for further improving child survival through prevention of childhood pneumonia by vaccination. Maximizing routine immunization with pertussis and measles vaccines, coupled with provision of a second opportunity for measles immunization, has rapidly reduced childhood deaths in low-income countries especially in sub-Saharan Africa. Vaccines against the two leading bacterial causes of child pneumonia deaths, Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (pneumococcus), can further improve child survival by preventing about 1,075,000 child deaths per year. Both Hib and pneumococcal conjugate vaccines have proven safety and effectiveness for prevention of radiologically confirmed pneumonia in children, including in low-income and industrializing countries. Both are recommended by WHO for inclusion in national programmes, and, at sharply tiered prices, these vaccines generally meet international criteria of cost-effectiveness for low-income countries. Vaccines only target selected pneumonia pathogens and are less than 100% effective, so they must be complemented by curative care and other preventative strategies. As part of a comprehensive child survival package, the particular advantages of vaccines include the ability to reach a high proportion of all children, including those who are difficult to reach with curative health services, and the ability to rapidly scale up coverage with new vaccines. In this review, we discuss advances made in optimizing the use of established vaccines and the potential issues related to newer bacterial conjugate vaccines in reducing childhood pneumonia morbidity and mortality.

Presentation, diagnosis and management of tuberculosis in HIV-infected children in the UK

OBJECTIVES

Management of HIV-infected children with tuberculosis (TB) is challenging. The objective of this study was to assess current treatment and outcomes in a resource-rich setting in the era of highly active antiretroviral therapy (HAART).

METHODS

A retrospective case-note review of coinfected children was carried out in a large UK-based HIV family clinic.

RESULTS

Of 328 HIV-infected children, 18 were diagnosed and treated for active TB. TB presentation led to HIV diagnosis in eight of these 18 children. TB was confirmed microbiologically in 33% of children. Fifteen of the 18 children presented with pulmonary TB, and three with extrapulmonary TB (EPTB). Immunological status at TB diagnosis did not predict EPTB. The mean CD4 T-cell count at TB presentation was 402 cells/microL (mean CD4 percentage 16%), with a range of 0-790 cells/microL (0-34%). In seven children concurrently treated with HAART and anti-tuberculous therapy (ATT), therapeutic drug monitoring (TDM) guided management. No immune reconstitution disease occurred. There was one death, unrelated to TB, 2 years after completion of ATT.

CONCLUSIONS

An HIV test should be considered in all children diagnosed with TB, especially if there are epidemiological risk factors. Our experience shows that, even with deferral of HAART in concurrently infected children, good therapeutic responses to ATT can be achieved. Where necessary, TDM guiding concurrent HAART and ATT can facilitate good clinical and virological responses.

Care and treatment of HIV-infected children in Africa: issues and challenges at the district hospital level

More than 90% of pediatric HIV infection occurs in sub-Saharan Africa and 75% of these children currently die before their fifth birthday. Most HIV-infected children in Africa rely on district hospitals for HIV treatment, but insufficient attention has been paid to improving HIV/AIDS care at this level. Considerable confusion exists about optimal use of combination antiretroviral treatment, prophylaxis for opportunistic infections and other rational healthcare interventions that can greatly improve the quality of life for these children. A simple and inexpensive infant HIV diagnostic assay and alternative laboratory markers of pediatric HIV disease progression would be highly beneficial. Routine anthropometric and neurodevelopmental assessments could help guide initiation and monitoring of antiretroviral therapy. Even in the absence of antiretroviral therapy, interventions such as immunizations, provision of micronutrients and nutrition counseling, prevention and treatment of opportunistic as well as endemic infections (such as helminths and malaria) can substantially reduce pediatric HIV-related morbidity and mortality. The need for pain relief, palliative care, counseling and emotional support is often underestimated. Surmounting the sense of hopelessness by providing district healthcare workers with training in basic pediatric HIV/AIDS care is an urgent priority.

Prevalences of Pneumocystis jiroveci, Mycobacterium tuberculosis and Streptococcus pneumoniae infection in children with severe pneumonia, in a tertiary referral hospital in northern Tanzania

At the Kilimanjaro Christian Medical Centre, a tertiary referral hospital in northern Tanzania, both the number of paediatric cases of lower respiratory-tract infection (LRTI) and the associated mortality increased between 2000 and 2001. Molecular diagnostic tools were used to enhance the identification of the pathogens responsible for this perceived increase. All 72 children aged between 2 and 60 months who were admitted with LRTI over a 3-month period were enrolled in the study. Induced sputum was collected from each child and, if the parents consented, the subjects were also tested for HIV. The sputum samples were each checked for bacteria by culture and, in amplification assays, for the DNA of Pneumocystis jiroveci, Mycobacterium tuberculosis and Streptococcus pneumoniae. Twenty-two (50%) of the 44 children tested for HIV had HIV-1 antibodies. Although only two children, both aged <6 months, were found PCR-positive for P. jiroveci, and only one was found positive for M. tuberculosis, 46 (including one of those found positive for P. jiroveci and the child found positive for M. tuberculosis) were found PCR-positive for S. pneumoniae. It therefore appears that most paediatric cases of LRTI who present at the hospital are attributable to S. pneumoniae, and that infections with this pathogen are entirely responsible for the observed increase in the incidence of LTRI in the local children. The increase seen in LRTI-associated mortality among the children may be the result of pneumococcal antibiotic resistance.

Sepsis predisposition in children with human immunodeficiency virus

OBJECTIVE

To review predisposition to sepsis in children infected with human immunodeficiency virus (HIV) in the era of highly active antiretroviral therapy (HAART).

DESIGN

Summary of the literature with review by experts in the field.

RESULTS

In industrialized regions, new diagnoses of vertically acquired HIV infection are falling due to perinatal interventions. Provision of HAART has resulted in an enlarging cohort of clinically stable HIV-infected children, with low viral loads and normal CD4 T-lymphocyte counts. Access to HAART in "developed" countries has markedly decreased the rate of progression to acquired immunodeficiency syndrome, the prevalence of organ-specific complications of HIV, the risk of recurrent sepsis, and the high early childhood mortality from HIV infection. There are currently no data on whether initiation of HAART during acute sepsis reduces short-term morbidity or mortality. Undiagnosed, antiretroviral-naive, HIV-infected infants still present sporadically with opportunistic infections such as Pneumocystis jiroveci and cytomegalovirus pneumonia. HIV-infected children have a greater burden of disease due to viral, bacterial, and fungal sepsis, and the case fatality rate for nonopportunistic infections may be greater than in non-HIV-infected children. In "developing" countries, with limited access to HAART, the natural history of HIV infection has altered very little, with the majority of infected children dying from either opportunistic or nonopportunistic disease before 3 yrs of age.

CONCLUSION

Pediatric HIV infection is not a homogeneous condition in the era of HAART. Susceptibility to sepsis, morbidity, and mortality differ according to stage of disease, access to HAART, and virologic and immunologic response to treatment. These issues should be considered if HIV-infected children are to be enrolled and stratified in clinical trials.

New agents for invasive mycoses in children

PURPOSE OF REVIEW

Invasive fungal infections are an important cause of morbidity and mortality in immunocompromised children of all ages. This review summarizes information on new antifungal agents, including current data on their clinical use in children, as well as alternative strategies such as antifungal combination and immunomodulation therapy.

RECENT FINDINGS

Novel antifungal agents, such as the echinocandins and the second-generation triazoles, were recently introduced that exhibit promising efficacy against Candida spp., Aspergillus spp., and other opportunistic fungal pathogens. These compounds are generally well tolerated and show substantial efficacy as salvage treatment and equal or even superior efficacy compared with older azoles or amphotericin B as first-line or empiric therapy for fungal infections. Clinical studies of pharmacokinetics and efficacy of the new agents in the pediatric population are, however, limited.

SUMMARY

The response rates observed with the recently introduced drugs, although superior in some cases compared with older antifungal agents, are still far from satisfactory. The development of new antifungal compounds as well as the use of alternative approaches of combination therapy and immunomodulation should be pursued through well-designed laboratory and clinical studies in pediatric patients.

Impact of HIV on childhood respiratory illness: differences between developing and developed countries

The main differences of the impact of HIV on childhood respiratory illness between developed and developing countries, and particularly some countries in Africa, are the scale of the problem and the lack of resources to address problems of prevention, diagnosis, and management. Recent data from HIV-infected African children are reviewed and show that the pattern of respiratory disease in these children is not markedly different to the pattern that was reported from the USA and Europe prior to the use of antiretroviral therapy and routine Pneumocystis jiroveci pneumonia (PCP) prophylaxis for HIV-exposed infants. Bacterial pneumonia is very common in all age groups. PCP and cytomegalovirus (CMV) are especially common in infants, and lymphoid interstitial pneumonitis (LIP) is common in older children. One difference is that pulmonary tuberculosis (PTB) is relatively more common in HIV-infected African children. This is likely to reflect the higher prevalence of smear-positive PTB in the region and therefore of exposure/infection compared to developed countries. Autopsy studies have provided a lot of useful data, but more prospective clinical and intervention studies from different parts of the region are needed in order to improve clinical diagnosis and management.

HIV and respiratory infections in children

Respiratory disease is a frequent cause of morbidity and mortality in children infected with human immunodeficiency virus (HIV). This review highlights recent data and developments that relate to the impact of HIV on respiratory infections particularly in African children. Autopsy and clinical studies continue to show that bacterial pneumonia and Pneumocystis jiroveci pneumonia (PCP) are common respiratory infections and causes of death in regions where antiretroviral therapy and PCP prophylaxis are not routinely practiced. Recent studies of Zambian and South African children showed that pulmonary tuberculosis is more common in HIV-infected children than was previously recognized. The trial of bacterial conjugate vaccines in Johannesburg will provide important information of efficacy in an HIV endemic population. Prospective clinical descriptive and intervention studies are needed from different regions to guide clinical management and prevention of respiratory infections in HIV-infected children living in resource-poor countries.