Second episode of tuberculosis in an HIV-infected child: relapse or reinfection?

Older age at first tuberculosis diagnosis is associated with tuberculosis recurrence in HIV-negative persons

SETTING

Tuberculosis (TB) clinic in Durban, South Africa.

OBJECTIVE

To assess the factors associated with TB recurrence among human immunodeficiency virus (HIV) negative adults and children.

DESIGN

We conducted a retrospective longitudinal study from January 2000 to December 2012. We defined recurrence as a TB episode occurring within the study period after treatment completion or cure of a previous episode. We used a multivariable Poisson regression model to assess the factors associated with the number of recurrences among HIV-negative patients.

RESULTS

Among 17 941 patients with known HIV status, 3653 (20%) were HIV-negative; of these, 235 (6%) had one recurrence, 21 (1%) had two recurrences and 4 (0.1%) had three recurrences. The median follow-up time from the end of treatment for the first episode was 3.0 years (interquartile range 1.9-4.2). Age at the first TB episode was significantly associated with the number of TB recurrences: younger patients had the lowest rate of recurrence, with a steady increase in rates until age 40 years, after which rates stabilized.

CONCLUSIONS

TB recurrence rates among HIV-negative patients were higher at increased age at the first TB episode. Further translational studies are needed to clarify the factors that drive multiple TB recurrences in older age, including impaired immunity, the results of which have implications for TB vaccine development.

Severe manifestations of extrapulmonary tuberculosis in HIV-infected children initiating antiretroviral therapy before 2 years of age

BACKGROUND

Early initiation of antiretroviral therapy (ART) in HIV-infected infants reduces mortality and opportunistic infections including tuberculosis (TB). However, young HIV-infected children remain at high risk of TB disease following mycobacterial infection. We document the spectrum of TB disease in HIV-infected children <2 years of age on ART.

METHODS

Retrospective cohort study; records of children <2 years of age initiating routine ART at Tygerberg Children's Hospital, Cape Town, January 2003-December 2010 were reviewed. Clinical data at ART initiation (baseline) and TB episodes after ART initiation, to June 2012, were recorded. TB immune reconstitution syndrome (TB-IRIS) and incident TB were defined as TB diagnosed within 3 months, and >3 months after, ART initiation respectively. Baseline characteristics were compared in children with TB-IRIS and those with incident TB.

RESULTS

In 494 children, median follow-up time on ART was 10.7 months. Fifty-five TB treatment episodes occurred after ART initiation: 23 (42%) TB-IRIS (incidence 21.9/100 person years (py)) and 32 (58%) incident TB (incidence 3.9/100 py). Children with TB-IRIS and those with incident TB had similar baseline characteristics. Eight of 10 cases of extrapulmonary TB were severe: 4 IRIS (2 meningitis, 1 disseminated, 1 pericarditis) and 4 incident cases (1 each miliary, meningitis, pericarditis and spinal). Fifty-one children (10%) died (mortality rate 5.96/100 py). Starting ART at <1 year of age approached significance as a risk factor for TB-IRIS (adjusted OR (AOR) 8.64, p=0.06); weight-for-age Z score <-2 predicted death (AOR 6.37, p<0.001).

CONCLUSIONS

Severe TB manifestations were observed among young HIV-infected children on ART.

Chronic lung disease in human immunodeficiency virus (HIV) infected children

The development of chronic lung disease is common in HIV-infected children. The spectrum of chronic HIV-associated lung disease includes lymphocytic interstitial pneumonia (LIP), chronic infections, immune reconstitution inflammatory syndrome (IRIS), bronchiectasis, malignancies, and interstitial pneumonitis. Chronic lung disease may result from recurrent or persistent pneumonia due to bacterial, mycobacterial, viral, fungal or mixed infections. In high tuberculosis (TB) prevalence areas, M. tuberculosis is an important cause of chronic respiratory illness. With increasing availability of highly active antiretroviral therapy (HAART) for children in developing countries, a rise in the incidence of IRIS due to mycobacterial or other infections is being reported. Diagnosis of chronic lung disease is based on chronic symptoms and persistent chest X-ray changes but definitive diagnosis can be difficult as clinical and radiological findings may be non-specific. Distinguishing LIP from miliary TB remains a difficult challenge in HIV-infected children living in high TB prevalence areas. Treatment includes therapy for specific infections, pulmonary clearance techniques, corticosteroids for children with LIP who are hypoxic or who have airway compression from tuberculous nodes and HAART. Children who are taking TB therapy and HAART need adjustments in their drug regimes to minimize drug interactions and ensure efficacy. Preventative strategies include immunization, chemoprophylaxis, and micronutrient supplementation. Early use of HAART may prevent the development of chronic lung disease.

Pneumonia in HIV-infected and HIV-uninfected children in developing countries

PURPOSE OF REVIEW

Pneumonia is a leading cause of illness and death in children younger than 5 years in developing countries, accounting for approximately 20% of childhood deaths. The HIV epidemic has sharply increased the incidence, severity, and mortality of childhood pneumonia in the developing world, particularly in sub-Saharan Africa. This article reviews recent findings on the epidemiology, clinical features, and management of HIV-infected and -uninfected children with pneumonia in developing countries.

RECENT FINDINGS

Bacterial infection remains a major cause of pneumonia mortality; in HIV-infected children, a broader spectrum of pathogens including gram-negative infections and Pneumocystis jiroveci occurs. Mycobacterium tuberculosis is an important cause of acute pneumonia among children from high tuberculosis prevalence areas. Use of case management guidelines substantially reduces neonatal, infant, and under-5 mortality and pneumonia-specific mortality in developing countries. New advances in therapy include the use of short-course antibiotics and high-dose amoxicillin twice daily for ambulatory treatment of HIV-negative children with pneumonia. New preventive interventions include the development of conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae, but these are not widely affordable nor available in developing countries. Despite a lower efficacy in HIV-infected children, these vaccines still protect against disease in a significant proportion of children. Available preventive interventions including micronutrient supplementation with zinc and vitamin A, and immunization as contained in the WHO Expanded Program of Immunization can substantially reduce the burden of childhood pneumonia.

SUMMARY

Urgent measures to implement existing available, effective interventions for prevention and treatment of childhood pneumonia and achieve high coverage rates in developing countries are needed.