Deaths due to respiratory tract infections in Africa: a review of autopsy studies

Postmortem for Intensified Missed Tuberculosis Case Finding in High Human Immunodeficiency Virus and Tuberculosis-burdened Settings in Sub-Saharan Africa among Adults' Population: Systematic Review and Meta-analysis

Tuberculosis (TB) is the leading infectious cause of mortality in sub-Saharan Africa (SSA); the high prevalence of TB in this region is due to human immunodeficiency virus (HIV)-coinfection. Despite the advent of modalities to diagnose TB, undiagnosed TB-related deaths among HIV-infected patients remain significantly high. This systematic review aims at characterizing missed TB cases from postmortem studies. This review informs on the burden of TB missed diagnosis and highlights the need of improving TB case-finding strategies, especially among the high-risk groups and early TB therapy initiation to keeping in with the World Health Organization's end TB strategy. We searched PubMed, Cochrane, Web of Science, and African journals online for studies that looked into missed TB cases following postmortem using the following key terms: postmortem, TB diagnosis, and HIV; we included cross-sectional and cohorts from 1980 in the English language that were carried out in SSA among adults' population. Authors used the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for reporting, the quality of the included studies was assessed using the Newcastle-Ottawa Scale for observational studies, and STATA 17.0 software was used for analysis. This study was registered in the International Prospective Register of Systematic Reviews with registration number CRD42024507515. The combined prevalence of postmortem missed TB diagnosis among the 6025 participants was 27.13% (95% confidence interval [CI] =14.52-41.89), with a high level of heterogeneity at 98.65% (P < 0.001). The prevalence varied significantly across the included studies, ranging from 1.21% (95% CI = 0.93-1.59) in the general population to 66.67% (95% CI = 50.98-79.37) in people living with HIV (PLWHIV). This current literature suggests that SSA is a region with a high prevalence of missed TB cases but with significant variations between countries. In addition, this study confirms a high number of missed TB infections within the PLWHIV. These results highlight the immediate need for targeted screening and diagnosis strategies and relevant policies.

A critical assessment of the cellular defences of the avian respiratory system: are birds in general and poultry in particular relatively more susceptible to pulmonary infections/afflictions?

In commercial poultry farming, respiratory diseases cause high morbidities and mortalities, begetting colossal economic losses. Without empirical evidence, early observations led to the supposition that birds in general, and poultry in particular, have weak innate and adaptive pulmonary defences and are therefore highly susceptible to injury by pathogens. Recent findings have, however, shown that birds possess notably efficient pulmonary defences that include: (i) a structurally complex three-tiered airway arrangement with aerodynamically intricate air-flow dynamics that provide efficient filtration of inhaled air; (ii) a specialised airway mucosal lining that comprises air-filtering (ciliated) cells and various resident phagocytic cells such as surface and tissue macrophages, dendritic cells and lymphocytes; (iii) an exceptionally efficient mucociliary escalator system that efficiently removes trapped foreign agents; (iv) phagocytotic atrial and infundibular epithelial cells; (v) phagocytically competent surface macrophages that destroy pathogens and injurious particulates; (vi) pulmonary intravascular macrophages that protect the lung from the vascular side; and (vii) proficiently phagocytic pulmonary extravasated erythrocytes. Additionally, the avian respiratory system rapidly translocates phagocytic cells onto the respiratory surface, ostensibly from the subepithelial space and the circulatory system: the mobilised cells complement the surface macrophages in destroying foreign agents. Further studies are needed to determine whether the posited weak defence of the avian respiratory system is a global avian feature or is exclusive to poultry. This review argues that any inadequacies of pulmonary defences in poultry may have derived from exacting genetic manipulation(s) for traits such as rapid weight gain from efficient conversion of food into meat and eggs and the harsh environmental conditions and severe husbandry operations in modern poultry farming. To reduce pulmonary diseases and their severity, greater effort must be directed at establishment of optimal poultry housing conditions and use of more humane husbandry practices.

Rapid and Accurate Diagnosis of Pediatric Tuberculosis Disease: A Diagnostic Accuracy Study for Pediatric Tuberculosis

INTRODUCTION

An estimated 1.2 million children develop tuberculosis (TB) every year with 240,000 dying because of missed diagnosis. Existing tools suffer from lack of accuracy and are often unavailable. Here, we describe the scientific and clinical methodology applied in RaPaed-TB, a diagnostic accuracy study.

METHODS

This prospective diagnostic accuracy study evaluating several candidate tests for TB was set out to recruit 1000 children <15 years with presumptive TB in 5 countries (Malawi, Mozambique, South Africa, Tanzania, India). Assessments at baseline included documentation of TB signs and symptoms, TB history, radiography, tuberculin skin test, HIV testing and spirometry. Respiratory samples for reference standard testing (culture, Xpert Ultra) included sputum (induced/spontaneous) or gastric aspirate, and nasopharyngeal aspirate (if <5 years). For novel tests, blood, urine and stool were collected. All participants were followed up at months 1 and 3, and month 6 if on TB treatment or unwell. The primary endpoint followed NIH-consensus statements on categorization of TB disease status for each participant. The study was approved by the sponsor's and all relevant local ethics committees.

DISCUSSION

As a diagnostic accuracy study for a disease with an imperfect reference standard, Rapid and Accurate Diagnosis of Pediatric Tuberculosis Disease (RaPaed-TB) was designed following a rigorous and complex methodology. This allows for the determination of diagnostic accuracy of novel assays and combination of testing strategies for optimal care for children, including high-risk groups (ie, very young, malnourished, children living with HIV). Being one of the largest of its kind, RaPaed-TB will inform the development of improved diagnostic approaches to increase case detection in pediatric TB.

Next Generation Sequencing Approaches to Characterize the Respiratory Tract Virome

The COVID-19 pandemic and heightened perception of the risk of emerging viral infections have boosted the efforts to better understand the virome or complete repertoire of viruses in health and disease, with a focus on infectious respiratory diseases. Next-generation sequencing (NGS) is widely used to study microorganisms, allowing the elucidation of bacteria and viruses inhabiting different body systems and identifying new pathogens. However, NGS studies suffer from a lack of standardization, in particular, due to various methodological approaches and no single format for processing the results. Here, we review the main methodological approaches and key stages for studies of the human virome, with an emphasis on virome changes during acute respiratory viral infection, with applications for clinical diagnostics and epidemiologic analyses.

A systematic review of clinical, epidemiological and demographic predictors of tuberculosis in children with pneumonia

Background

Tuberculosis (TB) can present as acute, severe pneumonia in children, but features which distinguish TB from other causes of pneumonia are not well understood. We conducted a systematic review to determine the prevalence and to explore clinical and demographic predictors of TB in children presenting with pneumonia over three decades.

Methods

We searched for peer-reviewed, English language studies published between 1990 and 2020 that included children aged between 1 month and 17 years with pneumonia and prospectively evaluated for TB. There were 895 abstracts and titles screened, and 72 full text articles assessed for eligibility.

Results

Thirteen clinical studies, two autopsy studies and one systematic review were included in analyses. Majority of studies were from Africa (12/15) and included children less than five years age. Prevalence of bacteriologically confirmed TB in children with pneumonia ranged from 0.2% to 14.8% (median = 3.7%, interquartile range (IQR) = 5.95) and remained stable over the three decades. TB may be more likely in children with pneumonia if they have a history of close TB contact, HIV infection, malnutrition, age less than one year or failure to respond to empirical antibiotics. However, these features have limited discriminatory value as TB commonly presents as acute severe pneumonia – with a short duration of cough, and clinical and radiographic features indistinguishable from other causes of pneumonia. Approximately half of patients with TB respond to initial empirical antibiotics, presumably due to bacterial co-infection, and follow-up may be critical to detect and treat TB.

Conclusion

TB should be considered as a potential cause or comorbidity in all children presenting with pneumonia in high burden settings. Clinicians should be alert to the presence of known risk factors for TB and bacteriological confirmation sought whenever possible. Quality data regarding clinical predictors of TB in childhood pneumonia are lacking. Further, prospective research is needed to better understand predictors and prevalence of TB in childhood pneumonia, particularly in TB endemic settings outside of Africa and in older children. Children of all ages with pneumonia should be included in research on improved, point-of-care TB diagnostics to support early case detection and treatment.

Pathology for Thoracic Conditions in Low- and Middle-Income Countries

Pulmonary disease in low- and middle-income countries is highly diverse and dependent on the population, background epidemiology, environmental exposures, and smoking status. Credible evaluation of lung diseases requires skilled clinicians, imaging infrastructure, microbiology, and pathologic diagnostics, including imaging-guided cytology and biopsy. When these tools are available, improvement in patient outcomes is feasible. Pathologic diagnostics of lung lesions, including histology, immunohistochemistry, and molecular testing, are critical to properly stratify patient risk and determine exact therapies for each patient. A critical focus on research and directed interventions in lung cancer treatment specifically is needed to downstage this disease and improve patient outcome.

Empirical treatment against cytomegalovirus and tuberculosis in HIV-infected infants with severe pneumonia: study protocol for a multicenter, open-label randomized controlled clinical trial

BACKGROUND

Pneumonia is the primary cause of death among HIV-infected children in Africa, with mortality rates as high as 35-40% in infants hospitalized with severe pneumonia. Bacterial pathogens and Pneumocystis jirovecii are well known causes of pneumonia-related death, but other important causes such as cytomegalovirus (CMV) and tuberculosis (TB) remain under-recognized and undertreated. The immune response elicited by CMV may be associated with the risk of developing TB and TB disease progression, and CMV may accelerate disease caused both by HIV and TB. Minimally invasive autopsies confirm that CMV and TB are unrecognized causes of death in children with HIV. CMV and TB may also co-infect the same child. The aim of this study is to compare the impact on 15-day and 1-year mortality of empirical treatment against TB and CMV plus standard of care (SoC) versus SoC in HIV-infected infants with severe pneumonia.

METHODS

This is a Phase II-III, open-label randomized factorial (2 × 2) clinical trial, conducted in six African countries. The trial has four arms. Infants from 28 to 365 days of age HIV-infected and hospitalized with severe pneumonia will be randomized (1:1:1:1) to (i) SoC, (ii) valganciclovir, (iii) TB-T, and (iv) TB-T plus valganciclovir. The primary endpoint of the study is all-cause mortality, focusing on the short-term (up to 15 days) and long-term (up to 1 year) mortality. Secondary endpoints include repeat hospitalization, duration of oxygen therapy during initial admission, severe and notable adverse events, adverse reactions, CMV and TB prevalence at enrolment, TB incidence, CMV viral load reduction, and evaluation of diagnostic tests such as GeneXpert Ultra on fecal and nasopharyngeal aspirate samples and urine TB-LAM.

DISCUSSION

Given the challenges in diagnosing CMV and TB in children and results from previous autopsy studies that show high rates of poly-infection in HIV-infected infants with respiratory disease, this study aims to evaluate a new approach including empirical treatment of CMV and TB for this patient population. The potential downsides of empirical treatment of these conditions include toxicity and medication interactions, which will be evaluated with pharmacokinetics sub-studies.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT03915366, Universal Trial Number U111-1231-4736, Pan African Clinical Trial Registry PACTR201994797961340.

Cytomegalovirus pneumonia of infants in Africa: a narrative literature review

Cytomegalovirus pneumonia has repeatedly been described in the context of HIV-exposed uninfected and HIV-infected infants. Despite its significant role in the etiology of childhood pneumonia, there is still a paucity of literature generally, and specifically in Africa, suggesting that it might be a neglected disease. Emerging evidence highlights the importance of postnatal transmission through breastmilk. The pathogenetic significance of the multiplicity of strains acquired through repeated re-infections in early infancy is unknown. The development of cheap, accurate diagnostic tools and safe, effective antivirals and the maintenance of effective prevention and treatment of pediatric HIV are needed to manage cytomegalovirus pneumonia in low-resource settings.

Child with hard calcified abdomen

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Tuberculosis has variable presentation in children most common being reduced appetite and failure to thrive.

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Children mostly suffer from primary tuberculosis without anyprior history of tubercular contact.

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Cyto/histopathological confirmation supplemented by staining for Acid Fast Bacilli remains the mainstay of diagnosis.

A young child with unsuspected tuberculosis (TB) presented with chronic pain abdomen along with off and on fever. He was admitted as case of lymphoma.

X ray of the chest and abdomen showed diffuse miliary calcified lymph nodes and omental nodules. Aspiration yielded dry tap and hence Cartridge Based Nucleic Acid Amplification Test (CBNAAT) was not done. Omental biopsy revealed occasional mature lymphocytes, epithelioid histiocytes forming ill-defined granuloma. Ziehl Neelsen stain was non-contributory.

The patient responded to anti tubercular drugs (prescribed for six months) and his abdomen softened. He was put on nutritional support which helped him regain health.

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.

Evaluation of the performance of clinical predictors in estimating the probability of pulmonary tuberculosis among smear-negative cases in Northern Ethiopia: a cross-sectional study

OBJECTIVES

To evaluate the performance of the predictors in estimating the probability of pulmonary tuberculosis (PTB) when all versus only significant variables are combined into a decision model (1) among all clinical suspects and (2) among smear-negative cases based on the results of culture tests.

DESIGN

A cross-sectional study.

SETTING

Two public referral hospitals in Tigray, Ethiopia.

PARTICIPANTS

A total of 426 consecutive adult patients admitted to the hospitals with clinical suspicion of PTB were screened by sputum smear microscopy and chest radiograph (chest X-ray (CXR)) in accordance with the Ethiopian guidelines of the National Tuberculosis and Leprosy Program. Discontinuation of antituberculosis therapy in the past 3 months, unproductive cough, HIV positivity and unwillingness to give written informed consent were the basis of exclusion from the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

A total of 354 patients were included in the final analysis, while 72 patients were excluded because culture tests were not done.

RESULTS

The strongest predictive variables of culture-positive PTB among patients with clinical suspicion were a positive smear test (OR 172; 95% CI 23.23 to 1273.54) and having CXR lesions compatible with PTB (OR 10.401; 95% CI 5.862 to 18.454). The regression model had a good predictive performance for identifying culture-positive PTB among patients with clinical suspicion (area under the curve (AUC) 0.84), but it was rather poor in patients with a negative smear result (AUC 0.64). Combining all the predictors in the model compared with only the independent significant variables did not really improve its performance to identify culture-positive (AUC 0.84-0.87) and culture-negative (AUC 0.64-0.69) PTB.

CONCLUSIONS

Our finding suggests that predictive models based on clinical variables will not be useful to discriminate patients with culture-negative PTB from patients with culture-positive PTB among patients with smear-negative cases.

Retrospective Validation of a Metagenomic Sequencing Protocol for Combined Detection of RNA and DNA Viruses Using Respiratory Samples from Pediatric Patients

Viruses are the main cause of respiratory tract infections. Metagenomic next-generation sequencing (mNGS) enables unbiased detection of all potential pathogens. To apply mNGS in viral diagnostics, sensitive and simultaneous detection of RNA and DNA viruses is needed. Herein, were studied the performance of an in-house mNGS protocol for routine diagnostics of viral respiratory infections with potential for automated pan-pathogen detection. The sequencing protocol and bioinformatics analysis were designed and optimized, including exogenous internal controls. Subsequently, the protocol was retrospectively validated using 25 clinical respiratory samples. The developed protocol using Illumina NextSeq 500 sequencing showed high repeatability. Use of the National Center for Biotechnology Information's RefSeq database as opposed to the National Center for Biotechnology Information's nucleotide database led to enhanced specificity of classification of viral pathogens. A correlation was established between read counts and PCR cycle threshold value. Sensitivity of mNGS, compared with PCR, varied up to 83%, with specificity of 94%, dependent on the cutoff for defining positive mNGS results. Viral pathogens only detected by mNGS, not present in the routine diagnostic workflow, were influenza C, KI polyomavirus, cytomegalovirus, and enterovirus. Sensitivity and analytical specificity of this mNGS protocol were comparable to PCR and higher when considering off-PCR target viral pathogens. One single test detected all potential viral pathogens and simultaneously obtained detailed information on detected viruses.

Potential of Minimally Invasive Tissue Sampling for Attributing Specific Causes of Childhood Deaths in South Africa: A Pilot, Epidemiological Study

BACKGROUND

Current estimates for causes of childhood deaths are mainly premised on modeling of vital registration and limited verbal autopsy data and generally only characterize the underlying cause of death (CoD). We investigated the potential of minimally invasive tissue sampling (MITS) for ascertaining the underlying and immediate CoD in children 1 month to 14 years of age.

METHODS

MITS included postmortem tissue biopsies of brain, liver, and lung for histopathology examination; microbial culture of blood, cerebrospinal fluid (CSF), liver, and lung samples; and molecular microbial testing on blood, CSF, lung, and rectal swabs. Each case was individually adjudicated for underlying, antecedent, and immediate CoD by an international multidisciplinary team of medical experts and coded using the International Classification of Diseases, Tenth Revision (ICD-10).

RESULTS

An underlying CoD was determined for 99% of 127 cases, leading causes being congenital malformations (18.9%), complications of prematurity (14.2%), human immunodeficiency virus/AIDS (12.6%), diarrheal disease (8.7%), acute respiratory infections (7.9%), injuries (7.9%), and malignancies (7.1%). The main immediate CoD was pneumonia, sepsis, and diarrhea in 33.9%, 19.7%, and 10.2% of cases, respectively. Infection-related deaths were either an underlying or immediate CoD in 78.0% of cases. Community-acquired pneumonia deaths (n = 32) were attributed to respiratory syncytial virus (21.9%), Pneumocystis jirovecii (18.8%), cytomegalovirus (15.6%), Klebsiella pneumoniae (15.6%), and Streptococcus pneumoniae (12.5%). Seventy-one percent of 24 sepsis deaths were hospital-acquired, mainly due to Acinetobacter baumannii (47.1%) and K. pneumoniae (35.3%). Sixty-two percent of cases were malnourished.

CONCLUSIONS

MITS, coupled with antemortem clinical information, provides detailed insight into causes of childhood deaths that could be informative for prioritization of strategies aimed at reducing under-5 mortality.

Human Immunodeficiency Virus Infection Impairs Th1 and Th17 Mycobacterium tuberculosis-Specific T-Cell Responses

Background

Human immunodeficiency virus (HIV)-infected individuals have a higher risk of developing active tuberculosis (TB) than HIV-uninfected individuals, but the mechanisms underpinning this are unclear. We hypothesized that depletion of specific components of Mycobacterium tuberculosis (Mtb)-specific CD4+ and CD8+ T-cell responses contributed to this increased risk.

Methods

Mtb-specific T-cell responses in 147 HIV-infected and 44 HIV-uninfected control subjects in a TB-endemic setting in Bloemfontein, South Africa, were evaluated. Using a whole-blood flow cytometry assay, we measured expression of interferon gamma, tumor necrosis factor alpha, interleukin 2, and interleukin 17 in CD4+ and CD8+ T cells in response to Mtb antigens (PPD, ESAT-6/CFP-10 [EC], and DosR regulon-encoded α-crystallin [Rv2031c]).

Results

Fewer HIV-infected individuals had detectable CD4+ and CD8+ T-cell responses to PPD and Rv2031c than HIV-uninfected subjects. Mtb-specific T cells showed distinct patterns of cytokine expression comprising both Th1 (CD4 and CD8) and Th17 (CD4) cytokines, the latter at highest frequency for Rv2031c. Th17 antigen-specific responses to all antigens tested were specifically impaired in HIV-infected individuals.

Conclusions

HIV-associated impairment of CD4+ and CD8+Mtb-specific T-cell responses is antigen specific, particularly impacting responses to PPD and Rv2031c. Preferential depletion of Th17 cytokine-expressing CD4+ T cells suggests this T-cell subset may be key to TB susceptibility in HIV-infected individuals.

Neurological disorders in HIV in Africa: a review

BACKGROUND

Neurological disorders in HIV infection are a common cause of morbidity and mortality. The aim of this paper is to provide a narrative overview of up to date information concerning neurological disorders affecting HIV infected persons in Africa.

METHODS

Seminal research concerning neurological disorders among HIV-infected adults in sub-Saharan Africa from prior to 2000 was combined with an in-depth search of PubMed to identify literature published from 2000 to 2017. The following Mesh terms were used. "Nervous System Diseases" "HIV Infections" and "Africa South of the Sahara" and "Seizures" or "Spinal Cord Diseases" or "Peripheral Nervous System Diseases" or "AIDS Dementia Complex" or "Opportunistic Infections" or "Immune Reconstitution Inflammatory Syndrome" or "Stroke". Only those articles written in English were used. A total of 352 articles were identified, selected and reviewed and 180 were included in the study. These included case series, observational studies, interventional studies, guidelines and reviews with metanalyses. The author also included 15 publications on the subject covering the earlier phase of the HIV epidemic in Africa from 1987 to 1999 making a total of 195 references in the study. This was combined with extensive personal experience diagnosing and treating these neurological disorders.

RESULTS

Neurological disorders were common, typically occurring in WHO stages III/IV. These were in three main categories: those arising from opportunistic processes mostly infections, direct HIV infection and autoimmunity. The most common were those arising from direct HIV infection occurring in >50%. These included HIV-associated neurocognitive dysfunction (HAND), neuropathy and myelopathy. Opportunistic infections occurred in >20% and frequently had a 6-9-month mortality rate of 60-70%. The main causes were cryptococcus, tuberculosis, toxoplasmosis and acute bacterial meningitis. Concurrent systemic tuberculosis occurred in almost 50%.

CONCLUSION

Neurological disorders are common in HIV in Africa and the main CNS opportunistic infections result in high mortality rates. Strategies aimed at reducing their high burden, morbidity and mortality include early HIV diagnosis and anti-retroviral therapy (ART), screening and chemoprophylaxis of main opportunistic infections, improved clinical diagnosis and management and programme strengthening.

Brief Report: Cofactors of Mortality Among Hospitalized HIV-Infected Children Initiating Antiretroviral Therapy in Kenya

OBJECTIVES

Identifying factors associated with mortality among acutely ill HIV-infected children presenting with advanced HIV disease may help clinicians optimize care for those at highest risk of death.

DESIGN

Using data from a randomized controlled trial (NCT02063880), we determined baseline sociodemographic, clinical, and laboratory cofactors of mortality among HIV-infected children in Kenya.

METHODS

We enrolled hospitalized, HIV-infected, antiretroviral therapy-naive children (0-12 years), initiated antiretroviral therapy, and followed up them for 6 months. We used Cox proportional hazards regression to estimate hazard ratios (HRs) for death and 95% confidence intervals (CIs).

RESULTS

Of 181 enrolled children, 39 (22%) died. Common diagnoses at death were pneumonia or suspected pulmonary tuberculosis [23 (59%)] and gastroenteritis [7 (18%)]. Factors associated with mortality in univariate analysis included age <2 years [HR 3.08 (95% CI: 1.50 to 6.33)], orphaned or vulnerable child (OVC) [HR 2.05 (95% CI: 1.09 to 3.84)], weight-for-age Z score <-2 [HR 2.29 (95% CI: 1.05 to 5.00)], diagnosis of pneumonia with hypoxia [HR 5.25 (95% CI: 2.00 to 13.84)], oral thrush [HR 2.17 (95% CI: 1.15 to 4.09)], persistent diarrhea [HR 3.81 (95% CI: 1.89 to 7.69)], and higher log10 HIV-1 viral load [HR 2.16 (95% CI: 1.35 to 3.46)] (all P < 0.05). In multivariable analysis, age <2 years and OVC status remained significantly associated with mortality.

CONCLUSIONS

Young age and OVC status independently predicted mortality. Hypoxic pneumonia, oral thrush, and persistent diarrhea are important clinical features that predict mortality. Strategies to enhance early diagnosis in children and improve hospital management of critically ill HIV-infected children are needed.

Factors Associated With Sputum Culture-Negative vs Culture-Positive Diagnosis of Pulmonary Tuberculosis

IMPORTANCE

Recognition of active tuberculosis (TB) in its earliest stages could reduce morbidity and prevent advancement to transmissible disease. Little is published about the occurrence and presentation of sputum culture-negative pulmonary TB (PTB), an early paucibacillary but often underrecognized disease state.

OBJECTIVE

To assess differences between culture-negative and culture-positive PTB regarding occurrence, clinical presentation, radiographic findings, demographics, and comorbidities.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study in which surveillance data of adult patients with PTB reported to the New York City Department of Health in New York, New York, from 2011 through 2013, ie, years for which demographic, clinical, and radiographic data were collected. Patients were aged 18 years or older, had signs of pulmonary disease, and had mycobacterial sputum culture results; those with HIV coinfection or a TB diagnosis within 2 years prior to presentation were excluded. Culture-negative PTB was defined as clinical and radiographic presentation consistent with TB, 3 negative results on sputum culture, and improvement with antituberculous treatment. The analyses were performed between 2015 and 2016; notably, the proportion of reported patients with culture-negative PTB has remained consistent during the past 2 decades.

MAIN OUTCOMES AND MEASURES

The occurrence of culture-negative PTB among all patients with PTB was calculated, and demographics, comorbidities, symptoms, and radiographic findings were compared between culture-negative and culture-positive PTB.

RESULTS

Of the 796 patients with PTB (median [interquartile range] age, 41 [29-54] years; 499 [63%] men) who met criteria for analysis, 116 (15%) had negative results on sputum culture. Patients with culture-negative PTB compared with culture-positive PTB were less frequently male (53% vs 64%; P = .03) and presented with a significantly lower frequency of cough (68% vs 89%; P < .001), weight loss (39% vs 51%; P = .03), and cavitation on both chest radiograph (7% vs 28%; P < .001) and chest computed tomographic scan (26% vs 59%; P < .001).

CONCLUSIONS AND RELEVANCE

Given the lack of criterion-standard test confirmation and the relative paucity of symptoms and radiological abnormalities, culture-negative PTB is likely underdiagnosed and its occurrence underestimated globally. Awareness of these findings, enhanced diagnostic approaches, and, ideally, better biomarkers could improve detection and treatment of this early disease and reduce the development of transmissible TB.

Trends, patterns and causes of respiratory disease mortality among inpatients in Tanzania, 2006-2015

OBJECTIVE

To determine the causes, patterns and trends of respiratory diseases-related deaths in hospitals of Tanzania 2006-2015.

METHODS

Retrospective study involving 39 hospitals. Medical records of patients who died in hospital were retrieved, reviewed and analysed. Sources of data were hospital admission registers, death registers and International Classification of Diseases report forms. Information on demographic characteristics, date of death, the immediate underlying cause of death and co-morbid conditions was collected.

RESULTS

Of the 247 976 deaths reported during the 10-year period, respiratory diseases accounted for 12.92% (n = 32 042). The majority of the respiratory mortality was reported among males (55.9%). Overall median age at death was 31 years with an interquartile range (IQR) of 1-47. Median age at death was significantly higher among males (35 years) than females (28 years) (P < 0.0001). Most deaths (37.8%) occurred in eastern Tanzania. About one-third (31.3%) of all respiratory mortality was reported among under-five children, being among girls than boys (34.3% vs. 28.9%, χ²  = 10.3, P < 0.0001). Adolescent and young adult females (15-29 years) had higher age-standardised mortality rates per 100 000 due respiratory diseases than males. Pneumonia (n = 16 639; 51.9%) and pulmonary tuberculosis (n = 9687; 30.2%) accounted for the majority of deaths due to respiratory diseases. Significantly more females (n = 7665; 54.5%) than males died from pneumonia (n = 8878; 49.8%; χ²  = 8.5, P < 0.0001). By contrast, significantly more males (n = 6024; 34%) than females (n = 3596; 26%; χ²  = 15.5, P < 0.0001) died of tuberculosis. The proportion of death due to tuberculosis declined from 32.8% in 2006-2010 to 7.9% in 2011-2015. However, there was a significant increase in the proportion of death due to pneumonia from 49.6% in 2006-2010 to 53.4% in 2011-2015. Co-morbid conditions contributed to 9.1% (2871/31 628) of all deaths due to respiratory diseases. The most common co-morbid condition was HIV which accounted for 1735 (60.4%) deaths and was more common among males (60.8%; n = 957) than among females (59.7%; n = 764).

CONCLUSIONS

Respiratory diseases account for a substantial proportion of all causes of hospital death in Tanzania. Pneumonia and tuberculosis contribute to more than three quarters of all deaths due to respiratory diseases. Since most major respiratory illnesses are avoidable, it is important to strengthen the capacity of the health delivery system in managing cases of respiratory diseases.

Prevalence of respiratory bacterial infections in people with lower respiratory tract infections in Africa: the BARIAFRICA systematic review and meta-analysis protocol

INTRODUCTION

The burden of lower respiratory tract infections (LRTIs) is a substantial public health concern. However, the epidemiology of LRTI and its bacterial aetiologies are poorly characterised, particularly in the African continent. Providing accurate data can help design cost-effective interventions to curb the burden of respiratory infections in Africa. Therefore, the aim of this systematic review and meta-analysis will be to determine the prevalence of respiratory Bacterial Aetiologies in people with low Respiratory tract Infections in Africa (BARIAFRICA) and associated factors.

METHODS AND ANALYSIS

We will search PubMed, EMBASE, Web of Science, African Journals Online, Cumulative Index to Nursing and Allied Health Literature, and Global Index Medicus to identify studies that reported the prevalence (of enough data to compute this estimate) of respiratory bacterial infections in people with LRTIs in Africa from 1 January 2000 to 31 March 2018, without any linguistic restrictions. Study selection, data extraction and risk of bias assessment will be conducted independently by two investigators. Heterogeneity will be evaluated using the χ² test on Cochran's Q statistic and quantified with H and I² statistics. Prevalence will be pooled using a random-effect meta-analysis model. Subgroup and meta-regression analyses will be used to identify sources of heterogeneity of prevalence estimates. This study will be reported according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

ETHICS AND DISSEMINATION

Since this study will be based on published data, it does not require ethical approval. This systematic review and meta-analysis is intended to serve as a basis for determining the burden of LRTIs, for identifying data gaps and for guiding future investigations in Africa. The final report will be published in peer-reviewed journals, presented in conferences and submitted to relevant health policy makers.

PROSPERO REGISTRATION NUMBER

CRD42018092359.

The Effect of Detectable HIV Viral Load among HIV-Infected Children during Antiretroviral Treatment: A Cross-Sectional Study

The RNA viral load of human immunodeficiency virus (HIV) is initially used to determine the status of the HIV infection. The goal of therapy following treatment failure is to achieve and maintain virologic suppression. A detectable viral load may relate to the progression of HIV infection. A cross-sectional survey was conducted from January 2013 to December 2014 at the Bamrasnaradura Infectious Diseases Institute, Thailand. The aim was to determine the prevalence of detectable HIV viral load (dVL) and analyze the factors associated with post-dVL conditions that occur independently of a switch to a new antiretroviral agent. The prevalence of dVL was 27% (27 of 101). The mean ages of dVL and non-dVL children were 12.0 and 12.3 years, respectively. Age, sex, body mass index for age z-scores, previous tuberculosis disease history and parental tuberculosis history of both groups were not significantly different (p > 0.05). The prevalence of poor adherence (<95%), influenza-like illness (ILI) and opportunistic infections were higher in dVL than non-dVL children (p < 0.05). The mean nadir CD4 cell count during the study was lower in dVL than non-dVL children (646 compared to 867, respectively; p < 0.05). Other factors were not significant (all p > 0.05). In multivariable analysis, dVL was significantly associated with ILI (odds ratio (OR) = 9.6, 95% confidence interval (CI) = 1.3–69.4), adherence (OR = 0.195, 95% CI = 0.047–0.811) and nadir CD4 during the study (OR = 1.102, 95% CI = 1.100–1.305). The prevalence of dVL was 27% with this dVL among HIV-infected children found to be associated with ILI, poor adherence and lower nadir CD4 during the study.

Point-of-care diagnostics for respiratory viral infections

Introduction: Successful treatment outcomes for viral respiratory tract infections presenting from primary health care to quaternary hospitals will only be achieved with rapid, sensitive and specific identification of pathogens to allow effective pathogen-specific antiviral therapy and infection control measures.

Areas covered: This review aims to explore the different point-of-care tests currently available to diagnose viral respiratory tract infections, discuss the advantages and limitations of point-of-care testing, and provide insights into the future of point-of-care tests. The following databases were searched: Medline (January 1996 to 30 September 2017) and Embase (1988 to 30 September 2017), using the following keywords: ‘point of care’, ‘respiratory virus’, ‘influenza’, ‘RSV’, ‘diagnostics’, ‘nucleic acid test’ and ‘PCR’.

Expert commentary: Viral respiratory tract infections cause significant morbidity and mortality worldwide, and point-of-care tests are facilitating the rapid identification of the pathogen responsible given the similarities in clinical presentation.

Clinical implications of rapid ePlex® Respiratory Pathogen Panel testing compared to laboratory-developed real-time PCR

Rapid diagnosis of respiratory infections is of great importance for adequate isolation and treatment. Due to the batch-wise testing, laboratory-developed real-time polymerase chain reaction (PCR) assays (LDT) often result in a time to result of one day. Here, LDT was compared with rapid ePlex® Respiratory Pathogen (RP) Panel testing of GenMark Diagnostics (Carlsbad, CA, USA) with regard to time to result, installed isolation precautions, and antibacterial/antiviral treatment. Between January and March 2017, 68 specimens of 64 patients suspected of an acute respiratory infection were tested with LDT and the ePlex® RP panel. The time to result was calculated as the time between sample reception and result reporting. Information regarding isolation and antibacterial/antiviral treatment was obtained from the patient records. Thirty specimens tested LDT positive (47%) and 29 ePlex® RP panel positive (45%). The median time to result was 27.1 h (range 6.5–96.6) for LDT versus 3.4 h (range 1.5–23.6) for the RP panel, p-value < 0.001. In 14 out of 30 patients, isolation was discontinued based on the ePlex® RP panel results, saving 21 isolation days. ePlex® RP panel test results were available approximately one day ahead of the LDT results in the 19 patients receiving antiviral/antibacterial treatment. In addition, two bacterial pathogens, not requested by the physician, were detected using the RP panel. Analysis of respiratory infections with the ePlex® RP panel resulted in a significant decrease in time to result, enabling a reduction in isolation days in half of the patients. Furthermore, syndromic RP panel testing increased the identification of causative pathogens.

Detection of Cytomegalovirus in Bronchoalveolar Lavage Fluid from HIV-Positive Individuals with Community Acquired Pneumonia

INTRODUCTION

Cytomegalovirus (CMV) pneumonia is one of the frequent viral pneumonia reported in persons with HIV infection. Knowledge of pulmonary CMV infection is important for deciding appropriate diagnostic strategies. However, there is scanty literature addressing the role of CMV aetiology among HIV positive individuals presenting with Community Acquired Pneumonia (CAP) using Bronchoalveolar Lavage (BAL) samples from India.

AIM

To detect CMV in BAL fluid from HIV-positive individuals presenting with CAP.

MATERIALS AND METHODS

This cross-sectional study was conducted using 107 archival BAL samples collected from consecutive HIV-positive patients presenting with CAP as per the Indian Chest Society and National College of Chest Physicians guidelines at the Department of Chest and Tuberculosis, Sassoon General Hospitals, Pune, India. The samples were tested for CMV by Polymerase Chain Reaction (PCR) targeting the IRL11 region at the National AIDS Research Institute, Pune.

RESULTS

Of the 107 BAL samples tested, 8 (7.4 %) were positive for CMV, while CMV was the sole pathogen in 5 (4.7%) cases. Co-infection with other pathogens was seen in 3 patients and Mycobacterium tuberculosis, Pneumocystis jiroveci and Streptococcus pneumoniae were the co-pathogens. Five patients had fatal clinical outcome of which three had CMV as the sole pathogen.

CONCLUSION

Ours is the first study to detect Cytomegalovirus (CMV) in bronchoalveolar lavage samples from HIV-positive individuals presenting with community acquired pneumonia from India and indicates the need for further multicentre studies to understand pulmonary CMV infection, which will eventually help in designing appropriate diagnostic strategies and therapeutic interventions.

Xpert MTB/RIF on Stool Is Useful for the Rapid Diagnosis of Tuberculosis in Young Children With Severe Pulmonary Disease

BACKGROUND

Tuberculosis (TB) continues to result in high morbidity and mortality in children from resource-limited settings. Diagnostic challenges, including resource-intense sputum collection methods and insensitive diagnostic tests, contribute to diagnostic delay and poor outcomes in children. We evaluated the diagnostic utility of stool Xpert MTB/RIF (Xpert) compared with bacteriologic confirmation (combination of Xpert and culture of respiratory samples).

METHODS

In a hospital-based study in Cape Town, South Africa, we enrolled children younger than 13 years of age with suspected pulmonary TB from April 2012 to August 2015. Standard clinical investigations included tuberculin skin test, chest radiograph and HIV testing. Respiratory samples for smear microscopy, Xpert and liquid culture included gastric aspirates, induced sputum, nasopharyngeal aspirates and expectorated sputum. One stool sample per child was collected and tested using Xpert.

RESULTS

Of 379 children enrolled (median age, 15.9 months, 13.7% HIV infected), 73 (19.3%) had bacteriologically confirmed TB. The sensitivity and specificity of stool Xpert versus overall bacteriologic confirmation were 31.9% [95% confidence interval (CI): 21.84%-44.50%] and 99.7% (95% CI: 98.2%-100%), respectively. A total of 23/51 (45.1%) children with bacteriologically confirmed TB with severe disease were stool Xpert positive. Cavities on chest radiograph were associated with Xpert stool positivity regardless of age and other relevant factors [odds ratios (OR) 7.05; 95% CI: 2.16-22.98; P = 0.001].

CONCLUSIONS

Stool Xpert can rapidly confirm TB in children who present with radiologic findings suggestive of severe TB. In resource-limited settings where children frequently present with advanced disease, Xpert on stool samples could improve access to rapid diagnostic confirmation and appropriate treatment.

Pneumonia in the developing world: Characteristic features and approach to management

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality in adults worldwide, but its epidemiology varies markedly by region. Whilst in high-income countries, the predominant burden of CAP is in the elderly and those with chronic cardiovascular and pulmonary co-morbidity, CAP patients in low-income settings are often of working age and, in sub-Saharan Africa, frequently HIV-positive. Although region-specific aetiological data are limited, they are sufficient to highlight major trends: in high-burden settings, tuberculosis (TB) is a common cause of acute CAP; Gram-negative pathogens such as Klebsiella pneumoniae are regionally important; and HIV-associated opportunistic infections are common but difficult to diagnose. These differences in epidemiology and aetiological profile suggest that modified approaches to diagnosis, severity assessment and empirical antimicrobial therapy of CAP are necessary, but tailored individualized management approaches are constrained by limitations in the availability of radiological and laboratory diagnostic services, as well as medical expertise. The widespread introduction of the Xpert MTB/RIF platform represents a major advance for TB diagnosis, but innovations in rapid diagnostics for other opportunistic pathogens are urgently needed. Severity assessment tools (e.g. CURB65) that are used to guide early management decisions in CAP have not been widely validated in low-income settings and locally adapted tools are required. The optimal approach to initial antimicrobial therapy choices such as the need to provide early empirical cover for atypical bacteria and TB remain poorly defined. Improvements in supportive care such as correcting hypoxaemia and intravenous fluid management represent opportunities for substantial reductions in mortality.

Early use of corticosteroids in infants with a clinical diagnosis of Pneumocystis jiroveci pneumonia in Malawi: a double-blind, randomised clinical trial

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is the most common opportunistic infection in infants with vertically acquired HIV infection and the most common cause of death in HIV-infected infants.

OBJECTIVES

To determine whether early administration of adjuvant corticosteroids in addition to standard treatment reduces mortality in infants with vertically acquired HIV and clinically diagnosed PJP when co-infection with cytomegalovirus and other pathogens cannot be excluded.

METHODS

A double-blind placebo-controlled trial of adjuvant prednisolone treatment in HIV-exposed infants aged 2-6 months admitted to Queen Elizabeth Central Hospital, Blantyre who were diagnosed clinically with PJP was performed. All recruited infants were HIV-exposed, and the HIV status of the infant was confirmed by DNA-PCR. HIV-exposed and infected infants as well as HIV-exposed but non-infected infants were included in the study. The protocol provided for the addition of prednisolone to the treatment at 48 h if there was clinical deterioration or an independent indication for corticosteroid therapy in any patient not receiving it. Oral trimethoprim-sulfamethoxazole (TMP/SMX) therapy and full supportive treatment were provided according to established guidelines. Primary outcomes for all patients included survival to hospital discharge and 6-month post-discharge survival.

RESULTS

It was planned to enroll 200 patients but the trial was stopped early because of recruitment difficulties and a statistically significant result on interim analysis. Seventy-eight infants were enrolled between April 2012 and August 2014; 36 infants (46%) were randomised to receive corticosteroids plus standard treatment with TMP/SMX, and 42 infants (54%) received the standard treatment plus placebo. In an intention-to treat-analysis, the risk ratio of in-hospital mortality in the steroid group compared with the standard treatment plus placebo group was 0.53 [95% CI 0.29-0.97, p = 0.038]. The risk ratio of mortality at 6 months was 0.63 (95% CI 0.41-0.95, p = 0.029). Two children who received steroids developed bloody stools while in hospital.

CONCLUSION

In infants with a clinical diagnosis of PJP, early use of steroids in addition to conventional TMP/SMX therapy significantly reduced mortality in hospital and 6 months after discharge.

Viral Lower Respiratory Tract Infections

Lower respiratory tract infections in children are often viral in origin. Unfortunately in this time of significant antimicrobial resistance of infectious organisms, especially bacteria, there is still a tendency for clinicians to manage a child who coughs with antibiotics. In addition, the World Health Organization (WHO) has defined “pneumonia” as a condition that only occurs in children who have “fast breathing or chest wall indrawing”. That would delineate upper respiratory tract infections from those in the lower airway. However, in addition to pneumonia another important entity exists in the lower respiratory tract that is almost always viral in origin. This condition is acute viral bronchiolitis. The concept of “acute lower respiratory tract infection” (ALRTI) has emerged and it is becoming increasing evident from a number of studies that the infectious base of both acute pneumonia (AP) and acute bronchiolitis in children has a mixed etiology of microorganisms. Therefore, whilst certain clinical phenotypes do not require antibiotics the actual microbial etiology is much less distinct.

Child pneumonia - focus on the Western Pacific Region

Worldwide, pneumonia is the leading cause of death in infants and young children (aged <5 years). We provide an overview of the global pneumonia disease burden, as well as the aetiology and management practices in different parts of the world, with a specific focus on the WHO Western Pacific Region. In 2011, the Western Pacific region had an estimated 0.11 pneumonia episodes per child-year with 61,900 pneumonia-related deaths in children less than 5 years of age. The majority (>75%) of pneumonia deaths occurred in six countries; Cambodia, China, Laos, Papua New Guinea, the Philippines and Viet Nam. Historically Streptococcus pneumoniae and Haemophilus influenzae were the commonest causes of severe pneumonia and pneumonia-related deaths in young children, but this is changing with the introduction of highly effective conjugate vaccines and socio-economic development. The relative contribution of viruses and atypical bacteria appear to be increasing and traditional case management approaches may require revision to accommodate increased uptake of conjugated vaccines in the Western Pacific region. Careful consideration should be given to risk reduction strategies, enhanced vaccination coverage, improved management of hypoxaemia and antibiotic stewardship.

Ethnobotany, phytochemistry, toxicology and pharmacological properties of Terminalia sericea Burch. ex DC. (Combretaceae) - A review

ETHNOPHARMACOLOGICAL REFERENCE

The use of medicinal plants in the treatment of infections is ancient. A wide variety of ethnotherapeutic properties and pharmacological actions has been attributed to Terminalia sericea. Studies by various groups of investigators reveal that it is a multipurpose medicinal plant used mostly in the treatment of diarrhoea, sexually transmitted infections, skin rashes, tuberculosis and other infections. The current paper is aimed at providing an overview of the ethnomedicinal uses, toxicology, pharmacology and the phytochemistry of Terminalia sericea.

MATERIALS AND METHODS

Information was retrieved using various search engines, including Pubmed, Science Direct, Google Scholar, Scielo, SciFinder and Scopus. The key words used included Terminalia sericea, secondary metabolites, phytochemistry, biological activity, pharmacology, ethnobotanical survey, medicinal uses, safety, toxicology and other related words.

RESULTS

Terminalia sericea is an important medicinal plant which possesses anti-HIV, anti-fungal, anti-bacterial, anticancer, lipolytic, wound healing, antiparasitic, anti-inflammatory and anti-oxidant activity, as the most valuable biological activities, thus lending pharmacological support to the plant's folkloric uses in indigenous medicine. Toxicologically, the extracts and isolated compounds from the plant species may have mild toxic effects. Phytochemically, the plant species possesses valuable compounds including triterpenes, alkaloids and flavonoids which may well contribute to its biological activity.

CONCLUSIONS

Terminalia sericea contains secondary metabolites which are valuable in the treatment of a variety of human infections, including community acquired infections which may be prevalent in developing countries. The degree of toxicity reported in various extracts warrants further exploration of the cytotoxicity of the plant species, both against normal human cell lines and in vivo. Moreover, the acetylcholinesterase inhibitory and anti-inflammatory effects also need to be further investigated as there are only a few reports from the literature on these aspects. There is also a need to further understand the mode of action of the extracts against various enzymes relating to inflammation. Antioxidant activity of the plant extracts against various forms of free radicals needs to be investigated. Although T. sericea is reported to be used for ethnoveterinary infections, there are no scientific reports on the anti-parasitic activity of the plant species against common animal parasites.

Improving access to tuberculosis preventive therapy and treatment for children

Children suffer a huge burden of disease in tuberculosis (TB) endemic countries. This disease burden was largely invisible when TB control programmes focused exclusively on adults with sputum smear-positive disease. High-level advocacy and better data have improved visibility, but the establishment of functional paediatric TB programmes remains challenging. The key issues that limit children's access to TB preventive therapy and treatment in endemic areas are briefly discussed. Barriers to preventive therapy include (1) the perceived inability to rule out active disease, (2) fear of creating drug resistance, (3) non-implementation of existing guidelines in the absence of adequate monitoring, and (4) poor adherence with long preventive therapy courses. Barriers to TB treatment include (1) perceived diagnostic difficulties, (2) non-availability of chest radiography, (3) young children presenting to unprepared maternal and child health (MCH) services, and (4) the absence of child-friendly formulations. With drug-resistant disease there is currently no guidance on the use of preventive therapy and treatment is usually restricted to cases with bacteriologically confirmed disease, which excludes most young children from care, even if their likely source case has documented drug-resistant TB.

Clinical utility of bronchoalveolar lavage cytomegalovirus viral loads in the diagnosis of cytomegalovirus pneumonitis in infants

Cytomegalovirus (CMV) pneumonitis is a significant cause of morbidity and mortality of children in Africa. The current practice for diagnosing CMV pneumonitis in this setting is based on interpretation of clinical, laboratory, and radiological findings. There is a need for a sensitive and specific laboratory test to objectively distinguish between patients with CMV pneumonitis and those with CMV infection, and non‐CMV pneumonia. In this study, we compared plasma and non‐bronchoscopic bronchoalveolar lavage (NBBAL) CMV viral loads in patients with CMV pneumonitis and those with CMV infection and non‐CMV pneumonia. Receiver operator characteristic curve analysis was used to establish a threshold and assess utility of viral loads in the diagnosis of CMV pneumonitis. We assessed the urea dilution method, and expression of viral loads relative to the total amount of extracted nucleic acids in correcting for NBBAL dilution. CMV quantification in NBBAL specimens was more predictive of CMV pneumonitis than blood CMV quantification. The threshold of 4.03 log IU/ml in NBBAL specimens has good predictive value and can be used to guide management of infants with suspected CMV pneumonitis. Adjusting for dilution of NBBAL specimens by using the urea dilution method or by expressing the viral load relative to the total nucleic acids extracted did not provide additional analytical benefits. J. Med. Virol. 89:1080–1087, 2017. © 2016 Wiley Periodicals, Inc.

Tuberculosis and pneumonia in HIV-infected children: an overview

Pneumonia remains the most common cause of hospitalization and the most important cause of death in young children. In high human immunodeficiency virus (HIV)-burden settings, HIV-infected children carry a high burden of lower respiratory tract infection from common respiratory viruses, bacteria and Mycobacterium tuberculosis. In addition, Pneumocystis jirovecii and cytomegalovirus are important opportunistic pathogens. As the vertical transmission risk of HIV decreases and access to antiretroviral therapy increases, the epidemiology of these infections is changing, but HIV-infected infants and children still carry a disproportionate burden of these infections. There is also increasing recognition of the impact of in utero exposure to HIV on the general health of exposed but uninfected infants. The reasons for this increased risk are not limited to socioeconomic status or adverse environmental conditions—there is emerging evidence that these HIV-exposed but uninfected infants may have particular immune deficits that could increase their vulnerability to respiratory pathogens. We discuss the impact of tuberculosis and other lower respiratory tract infections on the health of HIV-infected infants and children.

Global Burden of Childhood Tuberculosis

In 2015, the World Health Organization (WHO) declared tuberculosis (TB) to be responsible for more deaths than any other single infectious disease. The burden of TB among children has frequently been dismissed as relatively low with resulting deaths contributing very little to global under-five all-cause mortality, although without rigorous estimates of these statistics, the burden of childhood TB was, in reality, unknown. Recent work in the area has resulted in a WHO estimate of 1 million new cases of childhood TB in 2014 resulting in 136,000 deaths. Around 3% of these cases likely have multidrug-resistant TB and at least 40,000 are in HIV-infected children. TB is now thought to be a major or contributory cause of many deaths in children under five years old, despite not being recorded as such, and is likely in the top ten causes of global mortality in this age group. In particular, recent work has shown that TB is an under-lying cause of a substantial proportion of pneumonia deaths in TB-endemic countries. Childhood TB should be given higher priority: we need to identify children at greatest risk of TB disease and death and make more use of tools such as active case-finding and preventive therapy. TB is a preventable and treatable disease from which no child should die.

Review of cytomegalovirus coinfection in HIV-infected individuals in Africa

BACKGROUND

Cytomegalovirus (CMV) infection among HIV-infected individuals may cause end-organ disease, which is an AIDS-defining condition. Evidence from high-income countries suggests that CMV may alter the outcome of HIV infection, other than causing end-organ diseases. We reviewed literature on HIV and CMV coinfection in Africa.

METHODS

Systematic review of published studies on HIV and CMV coinfection in Africa using the PubMed database.

RESULTS

High CMV seroprevalence was found throughout Africa, exceeding 90% in most populations. Retinitis, pneumonia, and colitis were the most commonly reported CMV manifestations in HIV-infected individuals. Among patients with pulmonary symptoms, the prevalence of CMV pneumonitis varied from 20% to over 60%, whereas CMV was found in 0% to 14% of patients with gastrointestinal manifestations. Cytomegalovirus retinitis was found in 0% to 2.6% of examined HIV-infected individuals. The diagnostics of CMV end-organ diseases were found complex and difficult to interpret in African settings. Cytomegalovirus viremia was correlated with significantly lower CD4 cell count and increase in activated and apoptosis vulnerable T-lymphocytes. Also, CMV coinfection was found to be associated with increased transmission and progression of HIV infection. Moreover, detectable CMV DNA was an independent predictor of HIV transmission and mortality among HIV-infected individuals.

CONCLUSIONS

Cytomegalovirus is highly prevalent in Africa and a common cause of disease manifestations in HIV-infected individuals among all age groups. Cytomegalovirus coinfection in HIV-infected individuals in Africa is associated with increased transmission and mortality of HIV, but it is a neglected area of research.

Translating the Tuberculosis Research Agenda: Much Accomplished, but Much More to Be Done

Despite the availability of effective diagnostics and curative treatment regimens for tuberculosis, millions of people die each year of this disease. The steady global increase in the number of tuberculosis cases caused by multidrug-resistant and extensively drug-resistant strains of Mycobacterium tuberculosis are of major concern, especially in light of the thin tuberculosis drug pipeline. New tuberculosis drugs are undergoing clinical evaluation, and renewed hope comes from fresh approaches to improve treatment outcomes using a range of adjunct host-directed cellular and repurposed drug therapies. Current efforts in developing second-generation and new rapid point-of-care diagnostic assays take advantage of recent genetic and molecular advances. Slow progress in the development of prophylactic and therapeutic vaccines requires increased funding for basic as well as translational research. Although major challenges remain, these can be overcome by cementing our resolve, raising advocacy, bolstering global funder investments, and leveraging more effective collaborations through equitable public-private partnerships.

Limited value of whole blood Xpert(®) MTB/RIF for diagnosing tuberculosis in children

OBJECTIVES

We evaluated the ability of the Xpert(®) MTB/RIF assay to detect Mycobacterium tuberculosis in whole blood of children with tuberculosis in tuberculosis endemic settings with high rates of HIV infection.

METHODS

From June 2011 to September 2012 we prospectively enrolled children with symptoms or signs suggestive of tuberculosis at three research centres in Tanzania and Uganda. After clinical assessment, respiratory specimens were collected for microscopy and culture, as well as whole blood for Xpert(®) MTB/RIF. Children were classified according to standardised case definitions.

RESULTS

A total of 232 children were evaluated; 14 (6.0%) had culture-confirmed tuberculosis. The Xpert(®) MTB/RIF assay detected M. tuberculosis in 5/232 (2.2%) blood samples with 1 (0.4%) error reading and presumably 1 (0.4%) false-positive result. The sensitivity of the assay in children with culture-confirmed (1/14) versus no tuberculosis (1/117) was 7.1% (95% CI, 1.3-31.5). Three of the five Xpert(®) MTB/RIF positive patients had negative cultures, but were classified as probable tuberculosis cases. Assay sensitivity against a composite reference standard (culture-confirmed, highly probable or probable tuberculosis) was 5.4% (95% CI, 2.1-13.1).

CONCLUSION

Whole blood Xpert(®) MTB/RIF demonstrated very poor sensitivity, although it may enhance the diagnostic yield in select cases, with culture-negative tuberculosis.

Burden of respiratory tract infections at post mortem in Zambian children

BACKGROUND

Autopsy studies are the gold standard for determining cause-of-death and can inform on improved diagnostic strategies and algorithms to improve patient care. We conducted a cross-sectional observational autopsy study to describe the burden of respiratory tract infections in inpatient children who died at the University Teaching Hospital in Lusaka, Zambia.

METHODS

Gross pathology was recorded and lung tissue was analysed by histopathology and molecular diagnostics. Recruitment bias was estimated by comparing recruited and non-recruited cases.

RESULTS

Of 121 children autopsied, 64 % were male, median age was 19 months (IQR, 12-45 months). HIV status was available for 97 children, of whom 34 % were HIV infected. Lung pathology was observed in 92 % of cases. Bacterial bronchopneumonia was the most common pathology (50 %) undiagnosed ante-mortem in 69 % of cases. Other pathologies included interstitial pneumonitis (17 %), tuberculosis (TB; 8 %), cytomegalovirus pneumonia (7 %) and pneumocystis Jirovecii pneumonia (5 %). Comorbidity between lung pathology and other communicable and non-communicable diseases was observed in 80 % of cases. Lung tissue from 70 % of TB cases was positive for Mycobacterium tuberculosis by molecular diagnostic tests. A total of 80 % of TB cases were comorbid with malnutrition and only 10 % of TB cases were on anti-TB therapy when they died.

CONCLUSIONS

More proactive testing for bacterial pneumonia and TB in paediatric inpatient settings is needed.

Pulmonary specialty training to improve respiratory health in low- and middle-income countries. Needs and challenges

It is estimated that 85% of the world's population lives in low- and middle-income countries (LMICs). Although economic conditions are improving in these countries, health expenditures have not kept pace with the overall economic growth, and health systems remain weak. These already inadequate systems are being further stressed by the epidemiologic transition that is taking place, characterized by a slow decrease in communicable diseases and an increase in noninfectious chronic diseases, resulting in a "double burden" of infectious and noninfectious diseases. Respiratory diseases comprise the largest category of illness within this combined burden of disease. Although there are chronic respiratory disease programs of proven effectiveness appropriate for LMICs, implementation has been greatly hampered by the lack of physicians who have special knowledge and skills in addressing the full spectrum of lung diseases. Thus, there is an urgent need to create training programs for specialists in respiratory diseases. Such programs should be developed and conducted by institutions in LMICs and tailored to fit the prevailing circumstances of the country. Existing curriculum blueprints may be used to guide training program development with appropriate modifications. Academic institutions and professional societies in high-income countries may be called upon to provide technical assistance in developing and implementing training programs. In order to better define the burden of respiratory diseases and identify effective interventions, research, moved forward by persons committed and specialized in this area of health, will be essential.

Tuberculosis: opportunities and challenges for the 90-90-90 targets in HIV-infected children

INTRODUCTION

In 2014 the Joint United Nations Programme on HIV/AIDS defined the ambitious 90-90-90 targets for 2020, in which 90% of people living with HIV must be diagnosed, 90% of those diagnosed should be on sustained therapy and 90% of those on therapy should have an undetectable viral load. Children are considered to be a key focus population for these targets. This review will highlight key components of the epidemiology, prevention and treatment of tuberculosis (TB) in HIV-infected children in the era of increasing access to antiretroviral therapy (ART) and their relation to the 90-90-90 targets.

DISCUSSION

The majority of HIV-infected children live in countries with a high burden of TB. In settings with a high burden of both diseases such as in sub-Saharan Africa, up to 57% of children diagnosed with and treated for TB are HIV-infected. TB results in substantial morbidity and mortality in HIV-infected children, so preventing TB and optimizing its treatment in HIV-infected children will be important to ensuring good long-term outcomes. Prevention of TB can be achieved by increasing access to ART to both children and adults, and appropriate provision of isoniazid preventative therapy. Co-treatment of HIV and TB is complicated by drug-drug interactions particularly due to the use of rifampicin; these may compromise virologic outcomes if appropriate corrective actions are not taken. There remain substantial operational challenges, and improved integration of paediatric TB and HIV services, including with antenatal and routine under-five care, is an important priority.

CONCLUSIONS

TB may be an important barrier to achievement of the 90-90-90 targets, but specific attention to TB care in HIV-infected children may provide important opportunities to enhance the care of both TB and HIV in children.

Clinical and Radiographic Manifestations of Sputum Culture-Negative Pulmonary Tuberculosis

Intervention at the earliest possible stage of pulmonary tuberculosis (PTB) reduces morbidity for the individual and transmission for the community. We characterize the clinical and radiographic manifestations of sputum culture-negative (Cx-) PTB in order to facilitate awareness of this under recognized and likely early disease state. In this cross-sectional sub-study, we reviewed the medical records of HIV-uninfected PTB patients enrolled from 2006–2014 within the context of a TB biomarker study in New York City. Cx- PTB was defined as clinical and/or radiographic presentation consistent with PTB, three initial mycobacterial sputum cultures negative, and no evidence of other respiratory disease. Diagnosis was confirmed by clinical and radiographic improvement on antituberculous treatment and/or culture, nucleic acid, or histological confirmation from a specimen other than the initial three sputa. Cx+ PTB was defined as above but with M. tuberculosis growth in at least one of the first three sputum cultures. Demographics, symptoms, and radiographic findings on initial presentation were compared between the two groups. Of 99 subjects diagnosed with PTB, 21 met the criteria of Cx- PTB. Cx- compared to Cx+ subjects presented with a significantly lower frequency of cough (70% vs. 91%, P = 0.02), sputum production (30% vs. 64%, P < 0.01), weight loss (25% vs. 54%, P = 0.02), and frequency of cavitation on chest CT (12% vs. 68%, P < 0.01). Our findings should raise awareness that neither a positive culture nor the hallmark symptoms are invariably associated with early TB disease.

Prevalence of tuberculosis in post-mortem studies of HIV-infected adults and children in resource-limited settings: a systematic review and meta-analysis

Objectives:

Tuberculosis (TB) is estimated to be the leading cause of HIV-related deaths globally. However, since HIV-associated TB frequently remains unascertained, we systematically reviewed autopsy studies to determine the true burden of TB at death.

Methods:

We systematically searched Medline and Embase databases (to end 2013) for literature reporting on health facility-based autopsy studies of HIV-infected adults and/or children in resource-limited settings. Using forest plots and random-effects meta-analysis, we summarized the TB prevalence found at autopsy and used meta-regression to explore variables associated with autopsy TB prevalence.

Results:

We included 36 eligible studies, reporting on 3237 autopsies. Autopsy TB prevalence was extremely heterogeneous (range 0–64.4%), but was markedly higher in adults [pooled prevalence 39.7%, 95% confidence interval (CI) 32.4–47.0%] compared to children (pooled prevalence 4.5%, 95% CI 1.7–7.4%). Post-mortem TB prevalence varied by world region, with pooled estimates in adults of 63.2% (95% CI 57.7–68.7%) in South Asia (n = 2 studies); 43.2% (95% CI 38.0–48.3) in sub-Saharan Africa (n = 9 studies); and 27.1% (95% CI 16.0–38.1%) in the Americas (n = 5 studies). Autopsy prevalence positively correlated with contemporary estimates of national TB prevalence. TB in adults was disseminated in 87.9% (82.2–93.7%) of cases and was considered the cause of death in 91.4% (95% CI 85.8–97.0%) of TB cases. Overall, TB was the cause of death in 37.2% (95% CI 25.7–48.7%) of adult HIV/AIDS-related deaths. TB remained undiagnosed at death in 45.8% (95% CI 32.6–59.1%) of TB cases.

Conclusions:

In resource-limited settings, TB accounts for approximately 40% of facility-based HIV/AIDS-related adult deaths. Almost half of this disease remains undiagnosed at the time of death. These findings highlight the critical need to improve the prevention, diagnosis and treatment of HIV-associated TB globally.

Pathobiology of Pneumocystis pneumonia: life cycle, cell wall and cell signal transduction

Pneumocystis is a genus of ascomycetous fungi that are highly morbid pathogens in immunosuppressed humans and other mammals. Pneumocystis cannot easily be propagated in culture, which has greatly hindered understanding of its pathobiology. The Pneumocystis life cycle is intimately associated with its mammalian host lung environment, and life cycle progression is dependent on complex interactions with host alveolar epithelial cells and the extracellular matrix. The Pneumocystis cell wall is a varied and dynamic structure containing a dominant major surface glycoprotein, β-glucans and chitins that are important for evasion of host defenses and stimulation of the host immune system. Understanding of Pneumocystis cell signaling pathways is incomplete, but much has been deduced by comparison of the Pneumocystis genome with homologous genes and proteins in related fungi. In this mini-review, the pathobiology of Pneumocystis is reviewed, with particular focus on the life cycle, cell wall components and cell signal transduction.

Cryptococcal meningitis screening and community-based early adherence support in people with advanced HIV infection starting antiretroviral therapy in Tanzania and Zambia: an open-label, randomised controlled trial

BACKGROUND

Mortality in people in Africa with HIV infection starting antiretroviral therapy (ART) is high, particularly in those with advanced disease. We assessed the effect of a short period of community support to supplement clinic-based services combined with serum cryptococcal antigen screening.

METHODS

We did an open-label, randomised controlled trial in six urban clinics in Dar es Salaam, Tanzania, and Lusaka, Zambia. From February, 2012, we enrolled eligible individuals with HIV infection (age ≥18 years, CD4 count of <200 cells per μL, ART naive) and randomly assigned them to either the standard clinic-based care supplemented with community support or standard clinic-based care alone, stratified by country and clinic, in permuted block sizes of ten. Clinic plus community support consisted of screening for serum cryptococcal antigen combined with antifungal therapy for patients testing antigen positive, weekly home visits for the first 4 weeks on ART by lay workers to provide support, and in Tanzania alone, re-screening for tuberculosis at 6-8 weeks after ART initiation. The primary endpoint was all-cause mortality at 12 months, analysed by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Number registry, number ISCRTN 20410413.

FINDINGS

Between Feb 9, 2012, and Sept 30, 2013, 1001 patients were randomly assigned to clinic plus community support and 998 to standard care. 89 (9%) of 1001 participants in the clinic plus community support group did not receive their assigned intervention, and 11 (1%) of 998 participants in the standard care group received a home visit or a cryptococcal antigen screen rather than only standard care. At 12 months, 25 (2%) of 1001 participants in the clinic plus community support group and 24 (2%) of 998 participants in the standard care group had been lost to follow-up, and were censored at their last visit for the primary analysis. At 12 months, 134 (13%) of 1001 participants in the clinic plus community support group had died compared with 180 (18%) of 998 in the standard care group. Mortality was 28% (95% CI 10-43) lower in the clinic plus community support group than in standard care group (p=0·004).

INTERPRETATION

Screening and pre-emptive treatment for cryptococcal infection combined with a short initial period of adherence support after initiation of ART could substantially reduce mortality in HIV programmes in Africa.

FUNDING

European and Developing Countries Clinical Trials Partnership.

A retrospective analysis of the association between tobacco smoking and deaths from respiratory and cardiovascular diseases in the Kassena-Nankana districts of Northern Ghana

BACKGROUND

Tobacco use is a public health problem, responsible for approximately six million deaths annually worldwide. It is a risk factor for many diseases including cancers, respiratory and cardiovascular diseases. In low-and middle-income countries, respiratory and cardiovascular diseases are important causes of death. Tobacco use is prevalent in Ghana, but no study had examined the relationship between tobacco use and deaths from respiratory and cardiovascular diseases in the Upper East Region of Northern Ghana. Hence the paper assessed the association between tobacco use and deaths from respiratory and cardiovascular diseases in that region.

METHODS

The study used verbal autopsy data collected from the Kassena-Nankana East and West districts of the Upper East Region of Northern Ghana. Data from deceased individuals aged 15 to 59 years whose deaths occurred between January 1, 2004 and December 31, 2011 and with a known cause as well as smoking status were analyzed. Two binary outcome variables were generated from the cause of death data; whether an individual died from respiratory diseases or not, and from cardiovascular diseases or not. Multiple logistic regression models were used to assess the relationship between tobacco use and deaths from respiratory and cardiovascular diseases.

RESULTS

Out of 3,492 deaths with a known cause of death and smoking status, a third of them smoked. About 16.6% of smokers and 8.1% of non-smokers died from respiratory diseases. Approximately, 10.7% of smokers died from cardiovascular diseases compared to 10.6% of non-smokers. In multivariate analyses, individuals with a history of smoking had two-fold increased odds [OR=2.18, 95% CI (1.6-2.9)] of dying from respiratory diseases. Besides, the number of years of smoking as well as the frequency of smoking is significantly associated with deaths from respiratory diseases. No association existed between tobacco use and deaths from cardiovascular diseases.

CONCLUSIONS

Within our study we identified a strong relationship between tobacco use and deaths from respiratory diseases, but not an association with deaths from cardiovascular diseases. Our findings highlight the need to make appropriate health interventions to control tobacco use and thus help reduce premature deaths from respiratory and other tobacco linked diseases.

Burden of tuberculosis at post mortem in inpatients at a tertiary referral centre in sub-Saharan Africa: a prospective descriptive autopsy study

BACKGROUND

Patients with subclinical tuberculosis, smear-negative tuberculosis, extrapulmonary tuberculosis, multidrug-resistant tuberculosis, and asymptomatic tuberculosis are difficult to diagnose and may be missed at all points of health care. We did an autopsy study to ascertain the burden of tuberculosis at post mortem in medical inpatients at a tertiary care hospital in Lusaka, Zambia.

METHODS

Between April 5, 2012, and May 22, 2013, we did whole-body autopsies on inpatients aged at least 16 years who died in the adult inpatient wards at University Teaching Hospital, Lusaka, Zambia. We did gross pathological and histopathological analysis and processed lung tissues from patients with tuberculosis through the GeneXpert MTB/RIF assay to identify patients with multidrug-resistant tuberculosis. The primary outcome measure was specific disease or diseases stratified by HIV status. Secondary outcomes were missed tuberculosis, multidrug-resistant tuberculosis, and comorbidities with tuberculosis. Data were analysed using Pearson χ(2), the Mann-Whitney U test, and binary logistic regression.

FINDINGS

The median age of the 125 included patients was 35 years (IQR 29-43), 80 (64%) were men, and 101 (81%) were HIV positive. 78 (62%) patients had tuberculosis, of whom 66 (85%) were infected with HIV. 35 (45%) of these 78 patients had extrapulmonary tuberculosis. The risk of extrapulmonary tuberculosis was higher among HIV-infected patients than among uninfected patients (adjusted odds ratio 5·14, 95% CI 1·04-24·5; p=0·045). 20 (26%) of 78 patients with tuberculosis were not diagnosed during their life and 13 (17%) had undiagnosed multidrug-resistant tuberculosis. Common comorbidities with tuberculosis were pyogenic pneumonia in 26 patients (33%) and anaemia in 15 (19%).

INTERPRETATION

Increased clinical awareness and more proactive screening for tuberculosis and multidrug-resistant tuberculosis in inpatient settings is needed. Further autopsy studies are needed to ascertain the generalisability of the findings.

FUNDING

UBS Optimus Foundation, EuropeAID, and European Developing Countries Clinical Trials Partnership (EDCTP).

Tuberculosis as a cause or comorbidity of childhood pneumonia in tuberculosis-endemic areas: a systematic review

Pneumonia is a major cause of morbidity and mortality in infants and children worldwide, with most cases occurring in tuberculosis-endemic settings. Studies have emphasised the potential importance of Mycobacterium tuberculosis in acute severe pneumonia in children as a primary cause or underlying comorbidity, further emphasised by the changing aetiological range with rollout of bacterial conjugate vaccines in high mortality settings. We systematically reviewed clinical and autopsy studies done in tuberculosis-endemic settings that enrolled at least 100 children aged younger than 5 years with severe pneumonia, and that prospectively included a diagnostic approach to tuberculosis in all study participants. We noted substantial heterogeneity between studies in terms of study population and diagnostic methods. Of the 3644 patients who had culture of respiratory specimens for M tuberculosis undertaken, 275 (7·5%) were culture positive, and an acute presentation was common. Inpatient case-fatality rate for pneumonia associated with tuberculosis ranged from 4% to 21% in the four clinical studies that reported pathogen-related outcomes. Prospective studies are needed in high tuberculosis-burden settings to address whether tuberculosis is a cause or comorbidity of childhood acute severe pneumonia.