HIV testing and counselling is the first crucial step for linkage to HIV treatment and prevention. However, despite high HIV burden in sub-Saharan Africa, testing coverage is low, particularly among young adults and men. Community-based HIV testing and counselling (testing outside of health facilities) has the potential to reduce coverage gaps, but the relative impact of different modalities is not well assessed. We conducted a systematic review of HIV testing modalities, characterizing community (home, mobile, index, key populations, campaign, workplace and self-testing) and facility approaches by population reached, HIV positivity, CD4 count at diagnosis and linkage. Of 2,520 abstracts screened, 126 met eligibility criteria. Community HIV testing and counselling had high coverage and uptake and identified HIV-positive people at higher CD4 counts than facility testing. Mobile HIV testing reached the highest proportion of men of all modalities examined (50%, 95% confidence interval (CI) = 47–54%) and home with self-testing reached the highest proportion of young adults (66%, 95% CI = 65–67%). Few studies evaluated HIV testing for key populations (commercial sex workers and men who have sex with men), but these interventions yielded high HIV positivity (38%, 95% CI = 19–62%) combined with the highest proportion of first-time testers (78%, 95% CI = 63–88%), indicating service gaps. Community testing with facilitated linkage (for example, counsellor follow-up to support linkage) achieved high linkage to care (95%, 95% CI = 87–98%) and antiretroviral initiation (75%, 95% CI = 68–82%). Expanding home and mobile testing, self-testing and outreach to key populations with facilitated linkage can increase the proportion of men, young adults and high-risk individuals linked to HIV treatment and prevention, and decrease HIV burden. This article has not been written or reviewed by Nature editors. Nature accepts no responsibility for the accuracy of the information provided.

Importance Detection ofClostridioides difficilehas frequently been described in asymptomatic infants and children, but accurate estimates across the age spectrum are unavailable. Objective To assess the prevalence ofC difficiledetection among asymptomatic children across the age spectrum. Data Sources This systematic review and meta-analysis included a search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, Scopus, and Web of Science for articles published from January 1, 1990, to December 31, 2020. Search terms includedClostridium difficile,Peptoclostridium difficile,Clostridioides difficile,CDFORCDIORc diffORc difficile,Clostridium infectionsORcd positive diarrheaORcd positive diarrheaORClostridium difficileORPeptoclostridium difficileORpseudomembranous colitisORpseudomembranous enterocolitis,enterocolitis, andpseudomembranous. These were combined with the following terms:bacterial colonizationandcolonizationORcolonizedORcolonizingORepidemiologyORprevalenceORseroprevalence. Study Selection Studies were screened independently by 2 authors. Studies were included if they reported testing forC difficileamong asymptomatic children (ie, children without diarrhea) younger than 18 years. Data Extraction and Synthesis Data were extracted independently and in duplicate by 2 reviewers. Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA) guidelines were used. Data were pooled using a random-effects model. Main Outcomes and Measures The primary outcome was prevalence ofC difficiledetection among asymptomatic children. Secondary outcomes included prevalence of toxigenic vs nontoxigenic strains ofC difficileand prevalence ofC difficiledetection stratified by geographic region, income status, testing method, and year of testing. Results A total of 95 studies with 19 186 participants were included. Rates of detection of toxigenic or nontoxigenicC difficilewere greatest among infants aged 6 to 12 months (41%; 95% CI, 32%-50%) and decreased to 12% (95% CI, 7%-18%) among children aged 5 to 18 years. The prevalence of toxigenicC difficilecolonization was lower, peaking at 14% (95% CI, 8%-21%) among infants aged 6 to 12 months and decreasing to 6% (95% CI, 2%-11%) among children older than 5 years. Although prevalence differed by geographic region (ie, North and South America vs Europe: β, −0.151,P = .001; North and South America vs Western Pacific: β, 0.136,P = .007), there was no difference by testing method (ie, culture vs polymerase chain reaction: β, 0.069,P = .052; culture vs enzyme immunoassay: β, −0.178,P = .051), income class (low-middle income vs high income: β, −0.144,P = .23; upper-middle vs high income: β, −0.020,P = .64), or period (before 1990 vs 2010-2020: β, −0.125,P = .19; 1990-1999 vs 2010-2020: β, −0.037,P = .42; 2000-2009 vs 2010-2020: β, −0.006,P = .86). Conclusions and Relevance In this systematic review and meta-analysis,C difficilecolonization rates among children were greatest at 6 to 12 months of age and decreased thereafter. These estimates may provide context for interpretingC difficiletest results among young children.

Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) −0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI −87.8%, −2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.

Objective: Immunization rates are static in the United States. Risk factors for not being up to date (UTD) include ethnicity and lower socioeconomic status. Reminder cards increase immunization rates in urban settings. Their effect in poor, Latino, and rural children is unknown.

Background: The ability to identify bacterial pathogens that necessitate specific clinical management or public health action in children with acute gastroenteritis is crucial to patient care and public health. However, existing stool-testing guidelines offer inconsistent recommendations, and their performance characteristics are unknown. We evaluated 6 leading gastroenteritis guidelines (eg, those of the Centers for Disease Control and Prevention and Infectious Disease Society of America) that recommend when to test children’s stool for bacterial enteropathogens.Methods: Via 2 emergency departments in Alberta, Canada, we enrolled 2447 children <18 years old who presented with ≥3 episodes of diarrhea and/or vomiting in a 24-hour period. All participants were tested for 9 bacterial enteropathogens: Aeromonas, Campylobacter, Escherichia coli O157, other Shiga toxin–producing E. coli, enterotoxigenic E. coli, Salmonella, Shigella, Vibrio, and Yersinia. Patient data gathered at the index visit were used to determine whether guidelines would recommend testing. Sensitivity and specificity to recommend testing for children with bacterial enteropathogens were calculated for each guideline.Results: Outcome data were available for 2391 (97.7%) participants, and 6% (144/2391) of participants tested positive for a bacterial enteropathogen. Guideline sensitivity ranged from 25.8% (95% confidence interval [CI] 18.7–33.0%) to 66.9% (95% CI 59.3–74.6%), and varied for individual pathogens. Guideline specificity for all bacterial enteropathogens ranged from 63.6% (95% CI 61.6–65.6%) to 96.5% (95% CI 95.7–97.2%).Conclusions: No guideline provided optimally balanced performance. The most sensitive guidelines missed one-third of cases and would drastically increase testing volumes. The most specific guidelines missed almost 75% of cases.

Tobacco taxation and smoke-free workplaces reduce smoking, tobacco-related premature deaths and associated out-of-pocket health care expenditures. We examine the distributional consequences of a price increase in tobacco products through an excise tax hike, and of an implementation of smoke-free workplaces, in China. We use extended cost-effectiveness analysis (ECEA) to evaluate, across income quintiles of the male population (the large majority of Chinese smokers), the premature deaths averted, the change in tax revenues generated, and the financial risk protection procured (eg, poverty cases averted, defined as the number of individuals no longer facing tobacco-related out-of-pocket expenditures for disease treatment, that would otherwise impoverish them), that would follow a 75% increase in cigarette prices through substantial increments in excise tax fully passed onto consumers, and a nationwide total implementation of workplace smoking bans. A 75% increase in cigarette prices would avert about 24 million premature deaths among the current Chinese male population, with a third among the bottom income quintile, increase additional tax revenues by US$ 46 billion annually, and prevent around 9 million poverty cases, 19% of which among the bottom income quintile. Implementation of smoking bans in workplaces would avert about 12 million premature deaths, with a fifth among the bottom income quintile, decrease tax revenues by US$ 7 billion annually, and prevent around 4 million poverty cases, 12% of which among the bottom income quintile. Increased excise taxes on tobacco products and workplace smoking bans can procure large health and economic benefits to the Chinese population, especially among the poor.