Despite decades of high vaccination coverage, pertussis has remained endemic and reemerged as a public health problem in many countries in the past 2 decades. Waning of vaccine-induced immunity has been cited as one of the reasons for the observed epidemiologic trend. A review of the published data on duration of immunity reveals estimates that infection-acquired immunity against pertussis disease wanes after 4-20 years and protective immunity after vaccination wanes after 4-12 years. Further research into the rate of waning of vaccine-acquired immunity will help determine the optimal timing and frequency of booster immunizations and their role in pertussis control.

Exogenous reinfection appears to be a major cause of postprimary tuberculosis after a previous cure in an area with a high incidence of this disease. This finding emphasizes the importance of achieving cures and of preventing anyone with infectious tuberculosis from exposing others to the disease.

IRIS may affect 10% of patients initiating ART in Africa, particularly those with advanced immunosuppression, but severe, life-threatening IRIS is uncommon.

This study provides solid evidence that among infants for whom a source case was identified, household members were responsible for 76%-83% of transmission of Bordetella pertussis to this high-risk group. Vaccination of adolescents and adults in close contact with young infants may thus eliminate a substantial proportion of infant pertussis if high coverage rates can be achieved.

Summaryobjective To develop scales to measure tuberculosis and HIV ⁄ AIDS stigma in a developing world context.methods Cross-sectional study of tuberculosis patients in southern Thailand, who were asked to rate their agreement with items measuring TB and HIV ⁄ AIDS stigma. Developing the scales involved exploratory and confirmatory factor analyses, internal consistency, construct validity, test-retest reliability and standardized summary scores.results Factor analyses identified two sub-scales associated with both tuberculosis and HIV ⁄ AIDS stigma: community and patient perspectives. Goodness-of-fit was good (TLI = 94, LFI = 0.88 and RMSEA = 0.11), internal consistency was excellent (Cronbach's alphas 0.82-0.91), test-retest reliability was moderate, and construct validity showed an inverse correlation with social support.

Rationale:Multiple infections with different strains of Mycobacterium tuberculosis may occur in settings where the infection pressure is high. The relevance of mixed infections for the patient, clinician, and control program remains unclear. Objectives: This study aimed to describe reinfection and mixed infection as underlying mechanisms of changing drug-susceptibility patterns in serial sputum cultures. Methods: Serial M. tuberculosis sputum cultures from patients diagnosed with multi-drug-resistant (MDR) tuberculosis were evaluated by phenotypic drug-susceptibility testing and mutation detection methods. Genotypic analysis was done by IS6110 DNA fingerprinting and a novel strain-specific polymerase chain reaction amplification method. Measurements and Main Results: DNA fingerprinting analysis of serial sputum cultures from 48 patients with MDR tuberculosis attributed 10 cases to reinfection and 1 case to mixed infection. In contrast, strain-specific polymerase chain reaction amplification analysis in 9 of the 11 cases demonstrated mixed infection in 5 cases, reinfection in 3 cases, and laboratory contamination in 1 case. Analysis of clinical data suggests that firstline therapy can select for a resistant subpopulation, whereas poor adherence or second-line therapy resulted in the reemergence of the drug-susceptible subpopulations. Conclusions: We have shown that, in some patients with MDR tuberculosis, mixed infection may be responsible for observations attributed to reinfection by DNA fingerprinting. We conclude that treatment and adherence determines which strain is dominant. We hypothesize that treatment with second-line drugs may lead to reemergence of the drug-susceptible strain in patients with mixed infection. Keywords: drug resistance; mixed infections; Mycobacterium tuberculosis; reinfectionTraditionally, infection by Mycobacterium tuberculosis was assumed to be caused by a single strain, and recurrences were believed to be due to reactivation of the strain that caused the (Received in original form March 22, 2005; accepted in final form May 19, 2005) Supported by GlaxoSmithKline Action TB Program for funding the collection of clinical and demographic data, sputum culturing, and DNA fingerprinting; the Harry Crossley Foundation and the National Research Foundation (project 2054201 and the DST/NRF Centre of Excellence for Biomedical TB Research) for funding the development of the polymerase chain reaction-based strain-typing method; and the National Institutes of Health (R21 A155800-01) and the Wellcome Trust (DDS PC3145) for funding the identification of genotypic mechanisms conferring drug resistance.Correspondence and requests for reprints should be addressed to Robin M. Warren, Ph.D.,

BackgroundTuberculosis (TB) is an important cause of human suffering and death. Human immunodeficiency virus (HIV), multi-drug resistant TB (MDR-TB), and extensive drug resistant tuberculosis (XDR-TB) have emerged as threats to TB control. The association between MDR-TB and HIV infection has not yet been fully investigated. We conducted a systematic review and meta-analysis to summarize the evidence on the association between HIV infection and MDR-TB.Methods and ResultsOriginal studies providing Mycobacterium tuberculosis resistance data stratified by HIV status were identified using MEDLINE and ISI Web of Science. Crude MDR-TB prevalence ratios were calculated and analyzed by type of TB (primary or acquired), region and study period. Heterogeneity across studies was assessed, and pooled prevalence ratios were generated if appropriate. No clear association was found between MDR-TB and HIV infection across time and geographic locations. MDR-TB prevalence ratios in the 32 eligible studies, comparing MDR-TB prevalence by HIV status, ranged from 0.21 to 41.45. Assessment by geographical region or study period did not reveal noticeable patterns. The summary prevalence ratios for acquired and primary MDR-TB were 1.17 (95% CI 0.86, 1.6) and 2.72 (95% CI 2.03, 3.66), respectively. Studies eligible for review were few considering the size of the epidemics. Most studies were not adjusted for confounders and the heterogeneity across studies precluded the calculation of a meaningful overall summary measure.ConclusionsWe could not demonstrate an overall association between MDR-TB and HIV or acquired MDR-TB and HIV, but our results suggest that HIV infection is associated with primary MDR-TB. Future well-designed studies and surveillance in all regions of the world are needed to better clarify the relationship between HIV infection and MDR-TB.

Globally, an estimated 3.4 million children are living with HIV, yet little is known about the effects of HIV and antiretroviral treatment (ART) on the developing brain, and the neurodevelopmental and behavioural outcomes of perinatally HIV-infected (PHIV+) adolescents.We reviewed the literature on neurodevelopmental outcomes in PHIV+ children and adolescents, and summarized the current evidence on behaviour, general cognition, specific domains, hearing and language, school performance and physical disabilities due to neurological problems.Evidence suggests that PHIV+ children do not perform as well as controls on general cognitive tests, processing speed and visual–spatial tasks, and are at much higher risk for psychiatric and mental health problems. Children with AIDS-defining diagnoses are particularly at risk for poorer outcomes.A striking finding is the lack of published data specific to the adolescent age group (10–25 years), particularly from resource-constrained countries, which have the highest HIV prevalence. In addition, extreme heterogeneity in terms of timing and source of infection, and antiretroviral experience limits our ability to summarize findings of studies and generalize results to other settings.Due to the complex nature of the developing adolescent brain, environmental influences and variation in access to ART, there is an urgent need for research on the longitudinal trajectory of neurodevelopment among children and adolescents perinatally infected with HIV, especially in high burden resource-constrained settings.