Chest radiographic abnormalities in HIV-infected African children: a longitudinal study

Characterization of bacterial and viral pathogens in the respiratory tract of children with HIV-associated chronic lung disease: a case-control study

INTRODUCTION

Chronic lung disease is a major cause of morbidity in African children with HIV infection; however, the microbial determinants of HIV-associated chronic lung disease (HCLD) remain poorly understood. We conducted a case-control study to investigate the prevalence and densities of respiratory microbes among pneumococcal conjugate vaccine (PCV)-naive children with (HCLD +) and without HCLD (HCLD-) established on antiretroviral treatment (ART).

METHODS

Nasopharyngeal swabs collected from HCLD + (defined as forced-expiratory-volume/second < -1.0 without reversibility postbronchodilation) and age-, site-, and duration-of-ART-matched HCLD- participants aged between 6-19 years enrolled in Zimbabwe and Malawi (BREATHE trial-NCT02426112) were tested for 94 pneumococcal serotypes together with twelve bacteria, including Streptococcus pneumoniae (SP), Staphylococcus aureus (SA), Haemophilus influenzae (HI), Moraxella catarrhalis (MC), and eight viruses, including human rhinovirus (HRV), respiratory syncytial virus A or B, and human metapneumovirus, using nanofluidic qPCR (Standard BioTools formerly known as Fluidigm). Fisher's exact test and logistic regression analysis were used for between-group comparisons and risk factors associated with common respiratory microbes, respectively.

RESULTS

A total of 345 participants (287 HCLD + , 58 HCLD-; median age, 15.5 years [IQR = 12.8-18], females, 52%) were included in the final analysis. The prevalence of SP (40%[116/287] vs. 21%[12/58], p = 0.005) and HRV (7%[21/287] vs. 0%[0/58], p = 0.032) were higher in HCLD + participants compared to HCLD- participants. Of the participants positive for SP (116 HCLD + & 12 HCLD-), 66% [85/128] had non-PCV-13 serotypes detected. Overall, PCV-13 serotypes (4, 19A, 19F: 16% [7/43] each) and NVT 13 and 21 (9% [8/85] each) predominated. The densities of HI (2 × 104 genomic equivalents [GE/ml] vs. 3 × 102 GE/ml, p = 0.006) and MC (1 × 104 GE/ml vs. 1 × 103 GE/ml, p = 0.031) were higher in HCLD + compared to HCLD-. Bacterial codetection (≥ any 2 bacteria) was higher in the HCLD + group (36% [114/287] vs. (19% [11/58]), (p = 0.014), with SP and HI codetection (HCLD + : 30% [86/287] vs. HCLD-: 12% [7/58], p = 0.005) predominating. Viruses (predominantly HRV) were detected only in HCLD + participants. Lastly, participants with a history of previous tuberculosis treatment were more likely to carry SP (adjusted odds ratio (aOR): 1.9 [1.1 -3.2], p = 0.021) or HI (aOR: 2.0 [1.2 - 3.3], p = 0.011), while those who used ART for ≥ 2 years were less likely to carry HI (aOR: 0.3 [0.1 - 0.8], p = 0.005) and MC (aOR: 0.4 [0.1 - 0.9], p = 0.039).

CONCLUSION

Children with HCLD + were more likely to be colonized by SP and HRV and had higher HI and MC bacterial loads in their nasopharynx. The role of SP, HI, and HRV in the pathogenesis of CLD, including how they influence the risk of acute exacerbations, should be studied further.

TRIAL REGISTRATION

The BREATHE trial (ClinicalTrials.gov Identifier: NCT02426112 , registered date: 24 April 2015).

Tuberculosis revisted: classic imaging findings in childhood

Tuberculosis (TB) remains one of the major public health threats worldwide, despite improved diagnostic and therapeutic methods. Tuberculosis is one of the main causes of infectious disease in the chest and is associated with substantial morbidity and mortality in paediatric populations, particularly in low- and middle-income countries. Due to the difficulty in obtaining microbiological confirmation of pulmonary TB in children, diagnosis often relies on a combination of clinical and radiological findings. The early diagnosis of central nervous system TB is challenging with presumptive diagnosis heavily reliant on imaging. Brain infection can present as a diffuse exudative basal leptomeningitis or as localised disease (tuberculoma, abscess, cerebritis). Spinal TB may present as radiculomyelitis, spinal tuberculoma or abscess or epidural phlegmon. Musculoskeletal manifestation accounts for 10% of extrapulmonary presentations but is easily overlooked with its insidious clinical course and non-specific imaging findings. Common musculoskeletal manifestations of TB include spondylitis, arthritis and osteomyelitis, while tenosynovitis and bursitis are less common. Abdominal TB presents with a triad of pain, fever and weight loss. Abdominal TB may occur in various forms, as tuberculous lymphadenopathy or peritoneal, gastrointestinal or visceral TB. Chest radiographs should be performed, as approximately 15% to 25% of children with abdominal TB have concomitant pulmonary infection. Urogenital TB is rare in children. This article will review the classic radiological findings in childhood TB in each of the major systems in order of clinical prevalence, namely chest, central nervous system, spine, musculoskeletal, abdomen and genitourinary system.

Chest imaging findings of chronic respiratory disease in HIV-infected adolescents on combined anti retro viral therapy

Early treatment with combination antiretroviral therapy (cART) has improved survival of children perinatally infected with HIV into adolescence. This population is at risk of long term complications related to HIV infection, particularly chronic respiratory disease. Limited data on chest imaging findings in HIV-infected adolescents, suggest that the predominant disease is of small and large airways: predominantly bronchiolitis obliterans or bronchiectasis. Single cases of emphysema have been reported. Lung fibrosis, lymphocytic interstitial pneumonitis, post tuberculous apical fibrocystic changes and malignancies do not feature in this population. Chest radiograph (CXR) is easily accessible and widely used, especially in resource limited settings, such as sub Saharan Africa, where the greatest burden of HIV disease occurs. Lung ultrasound has been described for the diagnosis of pneumonia in children, pulmonary oedema and interstitial lung disease [1-3]. The use of this modality in chronic respiratory disease in adolescents where the predominant finding is small airway disease and bronchiectasis has however not been described. CXR is useful to evaluate structural/post infective changes, parenchymal opacification and nodules, hyperinflation or extensive bronchiectasis. CXR however, is inadequate for diagnosing small airway disease, for which high resolution computed tomography (HRCT) is the modality of choice. Where available, low dose HRCT should be used early in the course of symptomatic disease in adolescents and for follow up in children who are non responsive to treatment or clinically deteriorating. This article provides a pictorial review of the spectrum of CXR and HRCT imaging findings of chronic pulmonary disease in perinatally HIV-infected adolescents on cART and guidelines for imaging.

Respiratory Complications in Children and Adolescents with Human Immunodeficiency Virus

Respiratory complications comprise a large proportion of the burden of mortality and morbidity in children with human immunodeficiency virus (HIV). HIV-associated lower respiratory tract infection (LRTI) has declined in incidence with early diagnosis and use of antiretroviral therapy (ART) but is widespread in areas with limited access to ART. HIV-exposed uninfected infants have a higher risk of LRTI early in life than unexposed infants. Pulmonary tuberculosis (PTB) presenting as acute or chronic disease is common in highly TB endemic areas. Chronic lung disease is common; preceding LRTI, PTB or late initiation of ART are risk factors.

Chronic Lung Disease in Patients With Perinatally Acquired HIV in England: A Retrospective Case-Note Review

Chronic lung disease (CLD) is common in individuals living with perinatally acquired HIV (PA-HIV) in southern/eastern Africa. Most of the UK PA-HIV population are African. We conducted a case-note review of CLD in 3 UK PA-HIV cohorts (n = 98). Bronchiectasis or obliterative bronchiolitis occurred in 8.1% of patients and ring/tramline opacities occurred in 19.2% of patients on chest radiograph. There may be unrecognized and underdiagnosed CLD among PA-HIV in the UK.

Adolescent tuberculosis

Adolescence is characterised by a substantial increase in the incidence of tuberculosis, a known fact since the early 20th century. Most of the world's adolescents live in low-income and middle-income countries where tuberculosis remains common, and where they comprise a quarter of the population. Despite this, adolescents have not yet been addressed as a distinct population in tuberculosis policy or within tuberculosis treatment services, and emerging evidence suggests that current models of care do not meet their needs. This Review discusses up-to-date information about tuberculosis in adolescence, with a focus on the management of infection and disease, including HIV co-infection and rifampicin-resistant tuberculosis. We outline the progress in vaccine development and highlight important directions for future research.

History of tuberculosis is associated with lower exhaled nitric oxide levels in HIV-infected children

Objective:

HIV disrupts host defense mechanisms and maintains chronic inflammation in the lung. Nitric oxide is a marker of lung inflammation and can be measured in the exhaled air. We investigated the relationship between exhaled nitric oxide (eNO), HIV status and airway abnormalities in perinatally HIV-infected children aged 6–19 years.

Design:

A cross-sectional study.

Methods:

HIV-infected individuals on antiretroviral therapy and HIV-uninfected children with no active tuberculosis (TB) or acute respiratory tract infection were recruited from a public hospital in Harare, Zimbabwe. Clinical history was collected and eNO testing and spirometry was performed. The association between eNO and explanatory variables (HIV, FEV1 z-score, CD4⁺ cell count, viral load, history of TB) was investigated using linear regression analysis adjusted for age, sex and time of eNO testing.

Results:

In total, 222 HIV-infected and 97 HIV-uninfected participants were included. Among HIV-infected participants, 57 (25.7%) had a history of past TB; 56 (25.2%) had airway obstruction, but no prior TB. HIV status was associated with lower eNO level [mean ratio 0.79 (95% confidence interval, 95% CI 0.65–0.97), P = 0.03]. Within the HIV-infected group, history of past TB was associated with lower eNO levels after controlling for age, sex and time of eNO testing [0.79 (95% CI 0.67–0.94), P = 0.007].

Conclusion:

HIV infection and history of TB were associated with lower eNO levels. eNO levels may be a marker of HIV and TB-induced alteration in pulmonary physiology; further studies focused on potential causes for lower eNO levels in HIV and TB are warranted.

Bronchiectasis and other chronic lung diseases in adolescents living with HIV

PURPOSE OF REVIEW

The incidence of pulmonary infections has declined dramatically with improved access to antiretroviral therapy (ART) and cotrimoxazole prophylaxis, but chronic lung disease (CLD) is an increasingly recognized but poorly understood complication in adolescents with perinatally acquired HIV.

RECENT FINDINGS

There is a high prevalence of chronic respiratory symptoms, abnormal spirometry and chest radiographic abnormalities among HIV-infected adolescents in sub-Saharan Africa, wherein 90% of the world's HIV-infected children live. The incidence of lymphocytic interstitial pneumonitis, the most common cause of CLD in the pre-ART era, has declined with increased ART access. Small airways disease, particularly constrictive obliterative bronchiolitis and bronchiectasis, are emerging as leading causes of CLD among HIV-infected adolescents in low-income and middle-income countries. Asthma may be more common in high-income settings. Likely risk factors for CLD include recurrent pulmonary infections, air pollution, HIV-related immune dysfunction, and untreated HIV infection, particularly during critical stages of lung development.

SUMMARY

Globally, the importance of HIV-associated CLD as a cause of morbidity and mortality is increasing, especially as survival has improved dramatically with ART and growing numbers of children living with HIV enter adolescence. Further research is urgently needed to elucidate the natural history and pathogenesis of CLD, and to determine optimal screening, diagnostic and treatment strategies.

Risk Factors for Hypoxia and Tachypnea Among Adolescents With Vertically-acquired HIV in Nairobi

BACKGROUND

Chronic lung diseases are increasingly recognized complications of vertically-acquired HIV among adolescents in sub-Saharan Africa and may manifest with hypoxia or tachypnea. We sought to determine the prevalence of and risk factors for hypoxia and tachypnea among adolescents with vertically-acquired HIV in Nairobi, Kenya.

METHODS

We performed a cross-sectional analysis of 258 adolescents with vertically-acquired HIV who were initiating care at the Coptic Hope Center for Infectious Diseases. Adolescents with documented pneumonia were excluded. Hypoxia was defined as resting oxygen saturation ≤92%, and tachypnea was based on the 99th percentile of age-appropriate respiratory rates. Logistic regression models adjusted for demographics, and HIV severity estimated odds ratios for risk of hypoxia and tachypnea associated with potential risk factors.

RESULTS

Overall, 11% of adolescents had hypoxia and 55% had tachypnea. Advanced HIV [adjusted odds ratio (aOR): 2.41] and low CD4 (aOR: 1.74) were associated with greater hypoxia risk, but confidence intervals (CIs) were wide and included the null (95% CI: 0.93-6.23 and 0.69-4.39, respectively). Low CD4 (aOR: 2.45, 95% CI: 1.39-4.32), current antiretroviral therapy use (aOR: 0.48, 95% CI: 0.27-0.86) and stunted growth (aOR: 3.46, 95% CI: 1.94-6.18) were associated with altered tachypnea risk.

CONCLUSIONS

Hypoxia and tachypnea are common among adolescents with vertically-acquired HIV. There was a suggestion that advanced HIV and low CD4 were associated with greater hypoxia risk. Low CD4, lack of antiretroviral therapy use and stunted growth are risk factors for tachypnea. Our findings highlight the chronic lung disease burden in this population and may inform diagnostic algorithms.

Chronic lung disease in HIV-infected children established on antiretroviral therapy

Objective:

Respiratory disease is a major cause of morbidity and mortality in HIV-infected children. Despite antiretroviral therapy (ART), children suffer chronic symptoms. We investigated symptom prevalence, lung function and exercise capacity among older children established on ART and an age-matched HIV-uninfected group.

Design:

A cross-sectional study in Zimbabwe of HIV-infected children aged 6–16 years receiving ART for over 6 months and HIV-uninfected children attending primary health clinics from the same area.

Methods:

Standardized questionnaire, spirometry, incremental shuttle walk testing, CD4⁺ cell count, HIV viral load and sputum culture for tuberculosis were performed.

Results:

A total of 202 HIV-infected and 150 uninfected participants (median age 11.1 years in each group) were recruited. Median age at HIV diagnosis and ART initiation was 5.5 (interquartile range 2.8–7.5) and 6.1 (interquartile range 3.6–8.4) years, respectively. Median CD4⁺ cell count was 726 cells/μl, and 79% had HIV viral load less than 400 copies/ml. Chronic respiratory symptoms were rare in HIV-uninfected children [n = 1 (0.7%)], but common in HIV-infected participants [51 (25%)], especially cough [30 (15%)] and dyspnoea [30 (15%)]. HIV-infected participants were more commonly previously treated for tuberculosis [76 (38%) vs 1 (0.7%), P < 0.001], had lower exercise capacity (mean incremental shuttle walk testing distance 771 vs 889 m, respectively, P < 0.001) and more frequently abnormal spirometry [43 (24.3%) vs 15 (11.5%), P = 0.003] compared with HIV-uninfected participants. HIV diagnosis at an older age was associated with lung function abnormality (P = 0.025). No participant tested positive for Mycobacterium tuberculosis.

Conclusion:

In children, despite ART, HIV is associated with significant respiratory symptoms and functional impairment. Understanding pathogenesis is key, as new treatment strategies are urgently required.