Contact investigation of children exposed to tuberculosis in South East Asia: a systematic review

Background. Screening of children who are household contacts of tuberculosis (TB) cases is universally recommended but rarely implemented in TB endemic setting. This paper aims to summarise published data of the prevalence of TB infection and disease among child contacts in South East Asia. Methods. Search strategies were developed to identify all published studies from South East Asia of household contact investigation that included children (0-15 years). Results. Eleven studies were eligible for review. There was heterogeneity across the studies. TB infection was common among child contacts under 15 years of age (24.4-69.2%) and was higher than the prevalence of TB disease, which varied from 3.3% to 5.5%. Conclusion. TB infection is common among children that are household contacts of TB cases in South East Asia. Novel approaches to child contact screening and management that improve implementation in South East Asia need to be further evaluated.

Closing the policy-practice gap in the management of child contacts of tuberculosis cases in developing countries

Philip Campbell Hill and colleagues propose using a health needs assessment framework, research tools, and a strategy for clinical evaluation to help better manage child contacts of adult TB cases.

PCR improves diagnostic yield from lung aspiration in Malawian children with radiologically confirmed pneumonia

Background

Accurate data on childhood pneumonia aetiology are essential especially from regions where mortality is high, in order to inform case-management guidelines and the potential of prevention strategies such as bacterial conjugate vaccines. Yield from blood culture is low, but lung aspirate culture provides a higher diagnostic yield. We aimed to determine if diagnostic yield could be increased further by polymerase chain reaction (PCR) detection of bacteria (Streptococcus pneumoniae and Haemophilus influenzae b) and viruses in lung aspirate fluid.

Methods

A total of 95 children with radiological focal, lobar or segmental consolidation had lung aspirate performed and sent for bacterial culture and for PCR for detection of bacteria, viruses and Pneumocystis jirovecii. In children with a pneumococcal aetiology, pneumococcal bacterial loads were calculated in blood and lung aspirate fluid.

Results

Blood culture identified a bacterial pathogen in only 8 patients (8%). With the addition of PCR on lung aspirate samples, causative pathogens (bacterial, viral, pneumocystis) were identified singly or as co-infections in 59 children (62%). The commonest bacterial organism was S.pneumoniae (41%), followed by H. influenzae b (6%), and the commonest virus identified was adenovirus (16%), followed by human bocavirus (HBoV) (4%), either as single or co-infection.

Conclusions

In a select group of African children, lung aspirate PCR significantly improves diagnostic yield. Our study confirms a major role of S.pneumoniae and viruses in the aetiology of childhood pneumonia in Africa.

Magnetic resonance imaging and neuropsychological results from a trial of memantine in Alzheimer's disease

BACKGROUND

This study was designed to assess changes in brain volume and cognitive abilities in memantine-treated patients with Alzheimer's disease (AD) by using an exploratory, single-arm, delayed-start design.

METHODS

Cholinesterase inhibitor-treated patients with AD (N = 47; Mini-Mental State Examination score range: 15-23) were enrolled in an observational lead-in period (weeks: 1-24), followed by an open-label period of add-on memantine treatment (weeks: 25-48). The patients underwent magnetic resonance imaging at weeks 0 (baseline), 24 (immediately before memantine initiation), and 48 (endpoint), and a battery of neuropsychological tests at weeks 0, 24, 28, 36, and 48. The primary outcome measure was the annualized rate of change (%) in total brain volume (TBV) between the two study periods. Data were analyzed using paired t-tests.

RESULTS

There were no statistically significant differences in the rates of change in TBV, ventricular volume, or left hippocampal volume between the study periods; however, the memantine treatment period was associated with a significantly slower right hippocampal atrophy (-5.5% ± 12.0% vs -10.8% ± 7.2%; P = .038). Memantine treatment was also associated with superior performances on the Boston Naming Test (P = .034) and the Trail Making Test, Part B (P = .001), but also with a higher number of errors (i.e., repetitions and intrusions) on the California Verbal Learning Test. Memantine was found to be safe and well tolerated.

CONCLUSIONS

In this study, no difference in the rates of TBV change between the two periods was observed; however, memantine treatment was found to be associated with slowing of right hippocampal atrophy, and with improvement on one test of executive functioning as well as a test of confrontation naming ability. Trials using structural magnetic resonance imaging and a delayed-start design may be a feasible option for the assessment of treatments for AD.

Development of a clinical algorithm to prioritise HIV testing of hospitalised paediatric patients in a low resource moderate prevalence setting

OBJECTIVE

To develop a clinical algorithm to identify paediatric patients who should be offered HIV testing in a setting of moderate HIV prevalence and limited resources.

METHODS

In a prospective cross-sectional study at Port Moresby General Hospital, Papua New Guinea, carers of inpatients were offered HIV testing and counselling for their children. Recruited children were tested for HIV antibodies and DNA. Standardised clinical information was collected. Multivariate regression analysis was used to ascertain independent predictors of HIV infection and these were used to develop a predictive algorithm.

RESULTS

From September 2007 to October 2008, 487 children were enrolled. Overall, 55 (11%) with a median age of 7 months were found to be HIV-infected. In multivariate analysis, independent predictors of HIV infection were: persistent fever (OR = 2.05 (95% CI 1.11 to 4.68)), lymphadenopathy (OR = 2.29 (1.12 to 4.68)), oral candidiasis (OR = 3.94 (2.17 to 7.14)) and being underweight for age (OR = 2.03 (1.03 to 3.99)). The presence of any one of these conditions had a sensitivity of 96% in detecting a child with HIV infection. Using an algorithm based on the presence of at least one of these conditions would result in around 40% of hospitalised children being offered testing.

CONCLUSIONS

This clinical algorithm may be a useful screening tool for HIV infection in hospitalised children in situations where it is not feasible to offer universal HIV testing, providing guidance for HIV testing practices for increased identification and management of HIV-infected children in Papua New Guinea.

Oxygen is an essential medicine: a call for international action

Hypoxaemia is commonly associated with mortality in developing countries, yet feasible and cost-effective ways to address hypoxaemia receive little or no attention in current global health strategies. Oxygen treatment has been used in medicine for almost 100 years, but in developing countries most seriously ill newborns, children and adults do not have access to oxygen or the simple test that can detect hypoxaemia. Improving access to oxygen and pulse oximetry has demonstrated a reduction in mortality from childhood pneumonia by up to 35% in high-burden child pneumonia settings. The cost-effectiveness of an oxygen systems strategy compares favourably with other higher profile child survival interventions, such as new vaccines. In addition to its use in treating acute respiratory illness, oxygen treatment is required for the optimal management of many other conditions in adults and children, and is essential for safe surgery, anaesthesia and obstetric care. Oxygen concentrators provide the most consistent and least expensive source of oxygen in health facilities where power supplies are reliable. Oxygen concentrators are sustainable in developing country settings if a systematic approach involving nurses, doctors, technicians and administrators is adopted. Improving oxygen systems is an entry point for improving the quality of care. For these broad reasons, and for its vital importance in reducing deaths due to lung disease in 2010: Year of the Lung, oxygen deserves a higher priority on the global health agenda.

Metabolic resource allocation vs. mating attractiveness: Adaptive pressures on the "alba" polymorphism of Colias butterflies

The sex-limited "alba" genetic polymorphism in wing color of Colias butterflies has been studied with respect to potential selective pressures on this locus. Alba female pupae, carrying at least one dominant A allele, redirect resources, used by aa pupae for pigmentation, to other metabolic ends. Associated with this reallocation, alba, A-, female adults eclose earlier, retain more larva-derived resources in their fat bodies for somatic maintenance and for reproduction, and, in some conditions, mature their eggs faster than do aa females. Alba females are also less attractive to males than are aa females and mate less frequently. Evolutionary implications of these results are discussed.

Scale-up of services and research priorities for diagnosis, management, and control of tuberculosis: a call to action

The Millennium Development Goal target for tuberculosis control is to halt the spread of tuberculosis by 2015, and begin to reverse the worldwide incidence. After the introduction of standard control practices in 1995, 36 million people were cured and about 6 million deaths were averted. However, substantial scientific advances and innovative solutions are urgently needed together with creative new strategies. Strong international and national political commitment is essential. Urgent action is needed by national governments to fund their own programmes, and for the G8 countries and other donor governments and organisations to support governmental and non-governmental efforts. To foster the global need for urgent action to control the tuberculosis epidemic, The Lancet, in collaboration with the Stop TB Partnership, WHO, Global Fund to Fight AIDS, Tuberculosis and Malaria, and the experts participating in this Series, is launching The Lancet TB Observatory, which will assess and monitor progress in tuberculosis control and research, assess domestic and global financing, regularly disseminate information, and advocate for intensified efforts with stakeholders at all levels.

Impact of HIV on standard case management for severe pneumonia in children

It is estimated that 2 million children under 5 years of age die from pneumonia each year and that half of these deaths occur in sub-Saharan Africa. Over 85% of the more than 2.3 million children living with HIV worldwide reside in sub-Saharan Africa. HIV infection is likely to have a major impact on current recommendations for the standard case management of pneumonia in children and is the rationale for undertaking this review of published studies. The studies identified indicate an overall sixfold (range 2.5-13.5-fold) increase in pneumonia-related fatality in HIV-infected compared with HIV-uninfected African infants and children. They are more likely to have disease due to mixed infection and from a wider range of pathogens including Pneumocystis pneumonia, TB and cytomegalovirus. Scaling-up of the implementation of strategies that prevent HIV and Pneumocystis pneumonia remains an important strategy to reduce the burden of HIV-related pneumonia in the region. Research is urgently required to address the most effective pneumonia case management strategy in HIV-infected infants and children.

Importance of antibody and complement for oxidative burst and killing of invasive nontyphoidal Salmonella by blood cells in Africans

Bacteremia caused by nontyphoidal strains of Salmonella is endemic among African children. Case-fatality rates are high and antibiotic resistance increasing, but no vaccine is currently available. T cells are important for clearance of Salmonella infection within macrophages, but in Africa, invasive Salmonella disease usually manifests in the blood and affects children between 4 months and 2 y of age, when anti-Salmonella antibody is absent. We have previously found a role for complement-fixing bactericidal antibody in protecting these children. Here we show that opsonic activity of antibody and complement is required for oxidative burst and killing of Salmonella by blood cells in Africans. Induction of neutrophil oxidative burst correlated with anti-Salmonella IgG and IgM titers and C3 deposition on bacteria and was significantly lower in African children younger than 2 y compared with older children. Preopsonizing Salmonella with immune serum overcame this deficit, indicating a requirement for antibody and/or complement. Using different opsonization procedures, both antibody and complement were found to be necessary for optimal oxidative burst, phagocytosis and killing of nontyphoidal Salmonella by peripheral blood cells in Africans. Although most strains of African nontyphoidal Salmonella can be killed with antibody and complement alone, phagocytes in the presence of specific antibody and complement can kill strains resistant to killing by immune serum. These findings increase the likelihood that an antibody-inducing vaccine will protect against invasive nontyphoidal Salmonella disease in African children.

Pneumonia in severely malnourished children in developing countries - mortality risk, aetiology and validity of WHO clinical signs: a systematic review

OBJECTIVES

To quantify the degree by which moderate and severe degrees of malnutrition increase the mortality risk in pneumonia, to identify potential differences in the aetiology of pneumonia between children with and without severe malnutrition, and to evaluate the validity of WHO-recommended clinical signs (age-specific fast breathing and chest wall indrawing) for the diagnosis of pneumonia in severely malnourished children.

METHODS

Systematic search of the existing literature using a variety of databases (Medline, EMBASE, the Web of Science, Scopus and CINAHL).

RESULTS

Mortality risk: Sixteen relevant studies were identified, which universally showed that children with pneumonia and moderate or severe malnutrition are at higher risk of death. For severe malnutrition, reported relative risks ranged from 2.9 to 121.2; odds ratios ranged from 2.5 to 15.1. For moderate malnutrition, relative risks ranged from 1.2 to 36.5. Aetiology: Eleven studies evaluated the aetiology of pneumonia in severely malnourished children. Commonly isolated bacterial pathogens were Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Haemophilus influenzae. The spectrum and frequency of organisms differed from those reported in children without severe malnutrition. There are very few data on the role of respiratory viruses and tuberculosis. Clinical signs: Four studies investigating the validity of clinical signs showed that WHO-recommended clinical signs were less sensitive as predictors of radiographic pneumonia in severely malnourished children.

CONCLUSIONS

Pneumonia and malnutrition are two of the biggest killers in childhood. Guidelines for the care of children with pneumonia and malnutrition need to take into account this strong and often lethal association if they are to contribute to the UN Millennium Development Goal 4, aiming for substantial reductions in childhood mortality. Additional data regarding the optimal diagnostic approach to and management of pneumonia and malnutrition are required from regions where death from these two diseases is common.

Bacille Calmette-Guérin vaccine-related disease in HIV-infected children: a systematic review

OBJECTIVE

To describe the characteristics and risk of bacille Calmette-Guérin (BCG) vaccine related disease in human immunodeficiency virus (HIV) infected infants.

METHODS

Systematic literature review of articles published from 1950 to April 2009 in the English language. We identified all microbiologically confirmed cases of disseminated BCG disease in vertically HIV-infected children reported in the literature.

RESULTS

Sixteen observational studies and 11 case reports/series were included. Observational studies suffered from high rates of loss to follow-up and death. Loco-regional BCG disease was reported in both HIV-infected and non-infected children. Disseminated BCG disease was reported only in children with immunodeficiency and only in studies employing sophisticated laboratory techniques. Sixty-nine cases of disseminated BCG were identified in the literature: 47 cases were reported in six observational studies, the majority (41/47) from the Western Cape of South Africa. A Brazilian cohort study reported no cases of disseminated BCG amongst 66 HIV-infected children observed over a 7-year period. A recent South African surveillance study reported 32 cases of disseminated BCG over a 3-year period, estimating the risk of disseminated BCG to be 992 per 100,000 vaccinations in HIV-infected children. Few cases of severe disseminated TB were reported in the cohort studies among HIV-infected children vaccinated with BCG.

CONCLUSION

Data on the risk of BCG vaccination in HIV-infected children are limited. Targeted surveillance for BCG complications employing sophisticated diagnostic techniques is required to inform vaccination policy.

Memantine therapy of behavioral symptoms in community-dwelling patients with moderate to severe Alzheimer's disease

Memantine is a moderate-affinity, uncompetitive antagonist of N-methyl-D-aspartate receptors, approved for the treatment of moderate to severe Alzheimer's disease (AD). Available data suggest that, in addition to its benefits on cognition, function, and global status, memantine treatment may also help alleviate behavioral symptoms. This article provides an overview of the prevalence, assessment, and treatment of behavioral disturbances in AD, and summarizes current knowledge regarding the effects of memantine on the behavior of community-dwelling patients. We searched EMBASE and PubMed (January 1992 to October 2008) for reports on memantine trials that involved outpatients with moderate to severe AD. All previously unpublished data were obtained from Forest Laboratories, Inc. Behavioral outcomes were assessed in three completed, double-blind, placebo-controlled trials.Overall, patients who received memantine performed better on behavioral measures than those treated with placebo. Post-hoc analyses suggest that memantine treatment was associated with a reduced severity or emergence of specific symptoms, particularly agitation and aggression. Prospective, well-designed trials are warranted to evaluate the efficacy of memantine in patients with significant behavioral symptoms.

A prospective study of risk factors for herpes simplex virus type 2 acquisition among high-risk HIV-1 seronegative women in Kenya

OBJECTIVES

Several studies have demonstrated an association between herpes simplex virus type 2 (HSV-2) and HIV-1, but available data on risk factors for HSV-2 acquisition are limited. The objective of this analysis was to determine the incidence and risk factors for HSV-2 acquisition among HIV-1-seronegative female sex workers in Kenya.

METHODS

Between February 1993 and December 2006, HIV-1-seronegative women attending a municipal sexually transmitted infection (STI) clinic were invited to enroll in a prospective cohort study. Screening for HIV-1 and STIs were done at monthly follow-up visits. Archived blood samples were tested for HSV-2.

RESULTS

Of 1527 HIV-1-seronegative women enrolled, 302 (20%) were HSV-2 seronegative at baseline of whom 297 had at least one follow-up visit. HSV-2 incidence was high (23 cases/100 person-years; 115 cases). In multivariate analysis, HSV-2 was significantly associated with more recent entry into sex work, workplace and higher number of sex partners per week. Condom use was protective, although this was statistically significant only for the intermediate strata (25-75% condom use; HR 0.43; p = 0.05). There were statistical trends for bacterial vaginosis to increase HSV-2 risk (HR 1.56; p = 0.07) and for oral contraceptive use to decrease risk (HR 0.50; p = 0.08). The 23% annual HSV-2 incidence in this study is among the highest reported anywhere in the world.

CONCLUSIONS

Women were at increased risk if they had recently entered sex work, had a higher number of sex partners or worked in bars. HSV-2 risk reduction interventions are urgently needed among high-risk African women.