OBJECTIVE: Using an innovative data sharing model, we assessed the impacts of the COVID-19 pandemic on the health of people who inject drugs (PWID). DESIGN: The PWID Data Collaborative was established in 2021 to promote data sharing across PWID studies in North America. Contributing studies submitted aggregate data on 23 standardized indicators during four time periods: prepandemic (March 2019 to February 2020), early-pandemic (March 2020 to February 2021), mid-pandemic (March 2021 to February 2022), and late pandemic (March 2022 to February 2023). METHODS: We present study-specific and meta-analyzed estimates for the percentage of PWID who took medications for opioid use disorder, received substance use treatment, shared syringes or injection equipment, had a mental health condition, had been incarcerated, or had experienced houselessness. To examine change over time across indicators, we fit a random effects meta-regression model to prevalence estimates using time as a moderator. RESULTS: Thirteen studies contributed estimates to the Data Collaborative on these indicators, representing 6213 PWID interviews. We observed minimal change across prevalence of the six indicators between the prepandemic (March 2019 to February 2020) and three subsequent time periods, overall or within individual studies. Considerable heterogeneity was observed across study-specific and time-specific estimates. CONCLUSION: Limited pandemic-related change observed in indicators of PWID health is likely a result of policy and supportive service-related changes and may also reflect resilience among service providers and PWID themselves. The Data Collaborative is an unprecedented data sharing model with potential to greatly improve the quality and timeliness of data on the health of PWID.

Ground beef is a common source of US Salmonella illnesses and outbreaks. However, the demographic and socioeconomic factors that are related to risk in ground beef-associated outbreaks of Salmonella infections are poorly understood. We describe the individual-level demographic characteristics and county-level indicators of social vulnerability for people infected with Salmonella linked to outbreaks associated with ground beef in the United States during 2012-2018. Non-Hispanic (NH) White and NH American Indian/Alaska Native persons, and people living in non-metropolitan areas, were overrepresented among people in salmonellosis outbreaks linked to ground beef. Case patients disproportionately resided in counties with high social vulnerability, suggesting that one or more community social risk factors may contribute to or be associated with some food safety risks. Collecting and analyzing socioeconomic and demographic characteristics of people in outbreaks can help identify disparities in foodborne disease, which can be further characterized and inform equity-focused interventions.

Reports of tecovirimat-resistant mpox have emerged after widespread use of antiviral therapy during the 2022 mpox outbreak. Optimal management of patients with persistent infection with or without suspected resistance is yet to be established. We report a successfully treated case of severe mpox in California, USA, that had suspected tecovirimat resistance.

Tuberculosis (TB) drug supply disruptions are a recurring concern in the United States (1). Contributors to these disruptions include loss of manufacturers to the U.S. market, inefficient supply chains, and lack of active ingredients available for import.* The last severe U.S. TB drug shortage occurred in 2012, when isoniazid (INH) was temporarily unavailable for several months (2). INH and rifampin (RIF) are the cornerstones for treatment of drug-susceptible TB, and rifapentine (RPT), a long acting rifamycin, has been incorporated into shorter first-line regimens† to treat both latent TB infection (LTBI) (3) and TB disease§ (4). In recent years, the U.S. supply of several TB drugs has again been disrupted. The Food and Drug Administration has declared shortages of RPT (on March 25, 2020), RIF (on December 22, 2021), and INH (on May 17, 2023).¶ Approximately one fifth of all U.S. TB cases are reported from California (5). TB drug procurement is decentralized among the state’s 61 local TB programs,** mirroring the decentralization among U.S. states and territories. The California Department of Public Health and the California TB Controllers Association assessed the impact of the shortage on California’s TB programs.

Keeping the global food supply safe necessitates international collaborations between countries. Health and regulatory agencies routinely communicate during foodborne illness outbreaks, allowing partners to share investigational evidence. A 2016-2020 outbreak of Listeria monocytogenes infections linked to imported enoki mushrooms required a multinational collaborative investigation among the United States, Canada, Australia, and France. Ultimately, this outbreak included 48 ill people, 36 in the United States and 12 in Canada, and was linked to enoki mushrooms sourced from one manufacturer located in the Republic of Korea. Epidemiologic, laboratory, and traceback evidence led to multiple regulatory actions, including extensive voluntary recalls by three firms in the United States and one firm in Canada. In the United States and Canada, the Korean manufacturer was placed on import alert while other international partners provided information about their respective investigations and advised the public not to eat the recalled enoki mushrooms. The breadth of the geographic distribution of this outbreak emphasizes the global reach of the food industry. This investigation provides a powerful example of the impact of national and international coordination of efforts to respond to foodborne illness outbreaks and protect consumers. It also demonstrates the importance of fast international data sharing and collaboration in identifying and stopping foodborne outbreaks in the global community. Additionally, it is a meaningful example of the importance of food sampling, testing, and integration of sequencing results into surveillance databases.

IMPORTANCE: To achieve hepatitis C elimination, treatment programs need to engage, treat, and cure people who inject drugs. OBJECTIVE: To compare a low-threshold, nonstigmatizing hepatitis C treatment program that was colocated at a syringe service program (accessible care) with facilitated referral to local clinicians through a patient navigation program (usual care). DESIGN, SETTING, AND PARTICIPANTS: This single-site randomized clinical trial was conducted at the Lower East Side Harm Reduction Center, a syringe service program in New York, New York, and included 167 participants who were hepatitis C virus RNA-positive and had injected drugs during the prior 90 days. Participants enrolled between July 2017 and March 2020. Data were analyzed after all patients completed 1 year of follow-up (after March 2021). INTERVENTIONS: Participants were randomized 1:1 to the accessible care or usual care arm. MAIN OUTCOMES AND MEASURES: The primary end point was achieving sustained virologic response within 12 months of enrollment. RESULTS: Among the 572 participants screened, 167 (mean [SD] age, 42.0 [10.6] years; 128 (77.6%) male, 36 (21.8%) female, and 1 (0.6) transgender individuals; 8 (4.8%) Black, 97 (58.5%) Hispanic, and 53 (32.1%) White individuals) met eligibility criteria and were enrolled, with 2 excluded postrandomization (n=165). Baseline characteristics were similar between the 2 arms. In the intention-to-treat analysis, 55 of 82 participants (67.1%) in the accessible care arm and 19 of 83 participants (22.9%) in the usual care arm achieved a sustained virologic response (P<.001). Loss to follow-up (12.2% [accessible care] and 16.9% [usual care]; P=.51) was similar in the 2 arms. Of the participants who received therapy, 55 of 64 (85.9%) and 19 of 22 (86.3%) achieved a sustained virologic response in the accessible care and usual care arms, respectively (P=.96). Significantly more participants in the accessible care arm achieved all steps in the care cascade, with the greatest attrition in the usual care arm seen in referral to hepatitis C virus clinician and attending clinical visit. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, among people who inject drugs with hepatitis C infection, significantly higher rates of cure were achieved using the accessible care model that focused on low-threshold, colocated, destigmatized, and flexible hepatitis C care compared with facilitated referral. To achieve hepatitis C elimination, expansion of treatment programs that are specifically geared toward engaging people who inject drugs is paramount. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03214679.

BACKGROUND: Dried plasma spot specimens may be a viable alternative to traditional liquid plasma in field settings, but the diagnostic accuracy is not well understood. METHODS: Standard databases (PubMed and Medline), conferences, and grey literature were searched until January 2019. The quality of evidence was evaluated using STARD and QUADAS-2 criteria. We used univariate and bivariate random effects models to determine misclassification, sensitivity, and specificity across multiple thresholds, overall and for each viral load technology and to account for between-study variation. RESULTS: We identified 23 studies for inclusion in the systematic review that compared the diagnostic accuracy of dried plasma spots to plasma. Primary data from 16 of the 23 studies were shared and included in the meta-analysis, representing 18 countries, totaling 1,847 paired dried plasma spot:plasma data points. The mean bias of dried plasma spot specimens compared to plasma was 0.28 log10 copies/ml, while the difference in median viral load was 2.25 log10 copies/ml. More dried plasma spot values were undetectable compared to plasma values (43.6% vs. 29.8%). Analyzing all technologies together, the sensitivity and specificity of dried plasma spot specimens was >92% across all treatment failure thresholds compared and total misclassification <5.4% across all treatment failure thresholds compared. Some technologies had lower sensitivity or specificity; however, the results were typically consistent across treatment failure thresholds. DISCUSSION: Overall, dried plasma spot specimens performed relatively well compared to plasma with sensitivity and specificity values greater than 90% and misclassification rates less than 10% across all treatment failure thresholds reviewed.

Eastern equine encephalitis virus (EEEV), western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV) can cause fatal encephalitis in humans and equids. Some MAbs to the E1 glycoprotein are known to be cross-reactive, weakly neutralizing in vitro but can protect from disease in animal models. We investigated the mechanism of neutralization of VEEV infection by the broadly cross-reactive E1-specific MAb 1A4B-6. 1A4B-6 protected 3-week-old Swiss Webster mice prophylactically from lethal VEEV challenge. Likewise, 1A4B-6 inhibited virus growth in vitro at a pre-attachment step after virions were incubated at 37 °C and inhibited virus-mediated cell fusion. Amino acid residue N100 in the fusion loop of E1 protein was identified as critical for binding. The potential to elicit broadly cross-reactive MAbs with limited virus neutralizing activity in vitro but that can inhibit virus entry and protect animals from infection merits further exploration for vaccine and therapeutic developmental research.

According to the WHO, the Region of the Americas has the second lowest tobacco use prevalence of any WHO region.1 WHO projections based on trends since 2000 indicate that the Region of the Americas, which includes both North and South America, is the only region expected to achieve a 30% relative reduction in tobacco use by 2025.1 However, there are approximately 127 million persons who report smoking tobacco in the Americas Region,2 a majority of whom reside in North America.3 North America consists of 23 countries (see table 1) with a combined population of nearly 600 million people, or approximately 7.5% of the world’s population in 2019.4 Among North American countries, data from 2017 for persons aged 15 years or older show current tobacco smoking prevalence ranged from 6.0% in Panama to 27.8% in Cuba.5 Among students aged 13–15 years old in North American countries with available data through 2017, current tobacco smoking prevalence ranged from 4.4% in Dominican Republic to 18.1% in Mexico.5 Tobacco smoking among adults is higher among males than females across North America. However, the difference in prevalence between sexes in the Region of the Americas is among the lowest of any WHO region5; this pattern is particularly pronounced among youth, where tobacco smoking among girls is similar to or higher among boys in most countries.2 5

CDC's 2018 Guideline for current practices in pediatric mild traumatic brain injury (mTBI; also referred to as concussion herein) systematically identified the best up-to-date practices based on current evidence and, specifically, identified recommended practices regarding CT, MRI, and skull radiograph imaging. In this commentary, we discuss types of neuroimaging not discussed in the guideline in terms of their safety for pediatric populations, their potential application, and the research investigating the future use of certain modalities to aid in the diagnosis and treatment of mTBI in children. The role of neuroimaging in pediatric mTBI cases should be considered for the potential contribution to children's neural and social development, in addition to the immediate clinical value (as in the case of acute structural findings).Selective use of specific neuroimaging modalities in research has already been shown to detect aspects of diffuse brain injury, disrupted cerebral blood flow, and correlate physiological factors with persistent symptoms following mTBI. However, these advanced neuroimaging modalities are currently limited to the research arena, and any future clinical application of advanced imaging modalities in pediatric mTBI will require robust evidence for each modality's ability to provide measurement of the subtle conditions of brain development, disease, damage, or degeneration while accounting for variables at both non-injury and time-post-injury epochs. Continued collaboration and communication between researchers and health care providers is essential to investigate, develop, and validate the potential of advanced imaging modalities in pediatric mTBI diagnostics and management.

Previous studies investigating the association between dysmorphology and cognitive, behavioral, and developmental outcomes among individuals with autism spectrum disorder (ASD) have been limited by the binary classification of dysmorphology and lack of comparison groups. We assessed the association using a continuous measure of dysmorphology severity (DS) in preschool children aged 2-5 years (322 with ASD and intellectual disability [ID], 188 with ASD without ID, and 371 without ASD from the general population [POP]). In bivariate analyses, an inverse association between DS and expressive language, receptive language, fine motor, and visual reception skills was observed in children with ASD and ID. An inverse association of DS with fine motor and visual reception skills, but not expressive language and receptive language, was found in children with ASD without ID. No associations were observed in POP children. These results persisted after exclusion of children with known genetic syndromes or major morphologic anomalies. Quantile regression models showed that the inverse relationships remained significant after adjustment for sex, race/ethnicity, maternal education, family income, study site, and preterm birth. DS was not associated with autistic traits or autism symptom severity, behaviors, or regression among children with ASD with or without ID. Thus, DS was associated with a global impairment of cognitive functioning in children with ASD and ID, but only with fine motor and visual reception deficits in children with ASD without ID. A better understanding is needed for mechanisms that explain the association between DS and cognitive impairment in children with different disorders. LAY SUMMARY: We examined whether having more dysmorphic features (DFs) was related to developmental problems among children with autism spectrum disorder (ASD) with or without intellectual disability (ID), and children without ASD from the general population (POP). Children with ASD and ID had more language, movement, and learning issues as the number of DFs increased. Children with ASD without ID had more movement and learning issues as the number of DFs increased. These relationships were not observed in the POP group. Implications are discussed.

INTRODUCTION: Tobacco smoking is often more prevalent among those with lower socio-economic status (SES) in high-income countries, which can be driven by the inequalities in initiation and cessation of smoking. Smoking is a leading contributor to socio-economic disparities in health. To date, the evidence for any socio-economic inequality in smoking cessation is lacking, especially in low- and middle-income countries (LMICs). This study examined the association between cessation behaviours and SES of smokers from eight LMICs. METHODS: Data among former and current adult smokers aged 18 and older came from contemporaneous Global Adult Tobacco Surveys (2008-2011) and the International Tobacco Control Surveys (2009-2013) conducted in eight LMICs (Bangladesh, Brazil, China, India, Mexico, Malaysia, Thailand and Uruguay). Adjusted odds ratios (AORs) of successful quitting in the past year by SES indicators (household income/wealth, education, employment status, and rural-urban residence) were estimated using multivariable logistic regression controlling for socio-demographics and average tobacco product prices. A random effects meta-analysis was used to combine the estimates of AORs pooled across countries and two concurrent surveys for each country. RESULTS: Estimated quit rates among smokers (both daily and occasional) varied widely across countries. Meta-analysis of pooled AORs across countries and data sources indicated that there was no clear evidence of an association between SES indicators and successful quitting. The only exception was employed smokers, who were less likely to quit than their non-employed counterparts, which included students, homemakers, retirees, and the unemployed (pooled AOR approximately 0.8, p<0.10). CONCLUSION: Lack of clear evidence of the impact of lower SES on adult cessation behaviour in LMICs suggests that lower-SES smokers are not less successful in their attempts to quit than their higher-SES counterparts. Specifically, lack of employment, which is indicative of younger age and lower nicotine dependence for students, or lower personal disposable income and lower affordability for the unemployed and the retirees, may be associated with quitting. Raising taxes and prices of tobacco products that lowers affordability of tobacco products might be a key strategy for inducing cessation behaviour among current smokers and reducing overall tobacco consumption. Because low-SES smokers are more sensitive to price increases, tobacco taxation policy can induce disproportionately larger decreases in tobacco consumption among them and help reduce socio-economic disparities in smoking and consequent health outcomes.

BACKGROUND: Coverage of viral load testing remains low with only half of the patients in need having adequate access. Alternative technologies to high throughput centralized machines can be used to support viral load scale-up; however, clinical performance data are lacking. We conducted a meta-analysis comparing the Cepheid Xpert HIV-1 viral load plasma assay to traditional laboratory-based technologies. METHODS: Cepheid Xpert HIV-1 and comparator laboratory technology plasma viral load results were provided from 13 of the 19 eligible studies, which accounted for a total of 3790 paired data points. We used random effects models to determine the accuracy and misclassification at various treatment failure thresholds (detectable, 200, 400, 500, 600, 800 and 1000 copies/ml). RESULTS: Thirty percent of viral load test results were undetectable, while 45% were between detectable and 10 000 copies/ml and the remaining 25% were above 10 000 copies/ml. The median Xpert viral load was 119 copies/ml and the median comparator viral load was 157 copies/ml, while the log10 bias was 0.04 (0.02-0.07). The sensitivity and specificity to detect treatment failure were above 95% at all treatment failure thresholds, except for detectable, at which the sensitivity was 93.33% (95% confidence interval: 88.2-96.3) and specificity was 80.56% (95% CI: 64.6-90.4). CONCLUSION: The Cepheid Xpert HIV-1 viral load plasma assay results were highly comparable to laboratory-based technologies with limited bias and high sensitivity and specificity to detect treatment failure. Alternative specimen types and technologies that enable decentralized testing services can be considered to expand access to viral load.

The presence of multiple dysmorphic features in some children with autism spectrum disorder (ASD) might identify distinct ASD phenotypes and serve as potential markers for understanding causes and prognoses. To evaluate dysmorphology in ASD, children aged 3-6 years with ASD and non-ASD population controls (POP) from the Study to Explore Early Development were evaluated using a novel, systematic dysmorphology review approach. Separate analyses were conducted for non-Hispanic White, non-Hispanic Black, and Hispanic children. In each racial/ethnic group, ~ 17% of ASD cases were Dysmorphic compared with ~ 5% of POP controls. The ASD-POP differential was not explained by known genetic disorders or birth defects. In future epidemiologic studies, subgrouping ASD cases as Dysmorphic vs. Non-dysmorphic might help delineate risk factors for ASD.

We conducted a cohort study to identify characteristics associated with testing for, and testing positive for, coccidioidomycosis among patients with community-acquired pneumonia in southern California, USA. Limited and delayed testing probably leads to underdiagnosis among non-Hispanic black, Filipino, or Hispanic patients and among high-risk groups, including persons in whom antimicrobial drug therapy has failed.

The ratio of the index (2nd) finger to ring (4th) finger lengths (2D:4D) is a proxy for fetal testosterone and estradiol. Studies suggesting 2D:4D is inversely associated with autism spectrum disorder (ASD) in males were limited by lack of confounder and subgroup assessments. Studies of females are sparse. We examined associations between ASD and 2D:4D among children in the Study to Explore Early Development; we considered case subgroups and numerous potential demographic and maternal-perinatal health confounders. We observed a modest inverse association between ASD and right-hand 2D:4D in males; subgroup analyses indicated associations were limited to ASD cases with birth defects/genetic syndromes or dysmorphic features. We observed a positive association between ASD and left-hand 2D:4D in females, overall and within most case subgroups.

The development of vaccines against malaria and serodiagnostic tests for detecting recent exposure requires tools for antigen discovery and suitable animal models. The protein microarray is a high-throughput, sample sparing technique, with applications in infectious disease research, clinical diagnostics, epidemiology, and vaccine development. We recently demonstrated Qdot((R)) -based indirect immunofluorescence together with portable optical imager ArrayCAM((R)) using single isotype detection could replicate data using the conventional laser confocal scanner system. We developed a multiplexing protocol for simultaneous detection of IgG, IgA and IgM and compared samples from a controlled human malaria infection model with those from controlled malaria infections of Aotus nancymaae, a widely-used non-human primate model of human malaria. IgG profiles showed the highest concordance in number of reactive antigens; thus, of the 139 antigens recognized by human IgG antibody, 111 were also recognized by Aotus monkeys. Interestingly, IgA profiles were largely non-overlapping. Finally, on the path toward wider deployment of the portable platform, we show excellent correlations between array data obtained in 5 independent laboratories around the U.S. using the multiplexing protocol (R(2) : 0.60-0.92). This study supports the use of this platform for wider deployment, particularly in endemic areas where such a tool will have the greatest impact on global human health. This article is protected by copyright. All rights reserved.

BACKGROUND: This paper describes the methods and conceptual framework for Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study data collection. The National Institutes of Health, through the National Institute on Drug Abuse, is partnering with the Food and Drug Administration's (FDA) Center for Tobacco Products to conduct the PATH Study under a contract with Westat. METHODS: The PATH Study is a nationally representative, longitudinal cohort study of 45 971 adults and youth in the USA, aged 12 years and older. Wave 1 was conducted from 12 September 2013 to 15 December 2014 using Audio Computer-Assisted Self-Interviewing to collect information on tobacco-use patterns, risk perceptions and attitudes towards current and newly emerging tobacco products, tobacco initiation, cessation, relapse behaviours and health outcomes. The PATH Study's design allows for the longitudinal assessment of patterns of use of a spectrum of tobacco products, including initiation, cessation, relapse and transitions between products, as well as factors associated with use patterns. Additionally, the PATH Study collects biospecimens from consenting adults aged 18 years and older and measures biomarkers of exposure and potential harm related to tobacco use. CONCLUSIONS: The cumulative, population-based data generated over time by the PATH Study will contribute to the evidence base to inform FDA's regulatory mission under the Family Smoking Prevention and Tobacco Control Act and efforts to reduce the Nation's burden of tobacco-related death and disease.

On June 2, 2015, CDC was notified that a male airline passenger, aged 41 years, with a fever of 105.4 degrees F, headache, nausea, photophobia, diarrhea, and vomiting, which began approximately 3 hours after departure, was arriving to San Francisco, California, on a flight from Frankfurt, Germany. His symptoms reportedly started with neck stiffness 1 day earlier. Upon arrival, the patient was immediately transported to a local hospital, where he was in septic shock, which was followed by multisystem organ failure. Cerebrospinal fluid, obtained approximately 12 hours after initiation of treatment, was Gram stain- and culture-negative. Blood cultures, which were drawn before antibiotic treatment, were positive for Neisseria meningitides of indeterminate serogroup. A review of the patient's medical records revealed a history of paroxysmal nocturnal hemoglobinuria and current biweekly eculizumab (Soliris) therapy.

BACKGROUND: From December 2013 through May 2014, physicians, dermatopathologists, and public health authorities collaborated to characterize an outbreak of Mycobacterium marinum and other nontuberculous mycobacterial skin and soft tissue infections (SSTIs) associated with handling fish in New York City's Chinatown. Clinicopathologic and laboratory investigations were performed on a series of patients. METHODS: Medical records were reviewed for 29 patients. Culture results were available for 27 patients and 24 biopsy specimens were evaluated by histopathology, immunohistochemistry (IHC) staining for acid-fast bacilli (AFB), and mycobacterial polymerase chain reaction (PCR) assays. RESULTS: All patients received antibiotics. The most commonly prescribed antibiotic regimen was clarithromycin and ethambutol. Of the 29 patients in this case series, 16 (55%) received surgical treatment involving incision and drainage, mass excision, and synovectomy. Of these, 7 (44%) had deep tissue involvement. All patients showed improvement. For those with culture results, 11 of 27 (41%) were positive for M. marinum; the remainder showed no growth. Poorly formed granulomas (96%), neutrophils (75%), and necrosis (79%) were found in 24 biopsies. Of 15 cases that were culture-negative and analyzed by other methods, 9 were PCR positive for M. marinum group species, 8 were IHC positive, and 3 were positive by AFB stains. CONCLUSIONS: A multidisciplinary approach was used to identify cases in an outbreak of M. marinum infections. The use of histopathology, culture, and IHC plus PCR from full thickness skin biopsy can lead to improved diagnosis of M. marinum SSTIs compared to relying solely on mycobacterial culture, the current gold standard.

BACKGROUND & AIMS: Chronic hepatitis B virus (HBV) infection is an important cause of cirrhosis and hepatocellular carcinoma worldwide; populations that migrate to the US and Canada might be disproportionately affected. The Hepatitis B Research Network (HBRN) is a cooperative network of investigators from the United States and Canada, created to facilitate clinical, therapeutic, and translational research in adults and children with hepatitis B. We describe the structure of the network and baseline characteristics of adults with hepatitis B enrolled in the network. METHODS: The HBRN collected data on clinical characteristics of 1625 adults with chronic HBV infection who are not receiving antiviral therapy from 21 clinical centers in North America. RESULTS: Half of the subjects in the HBRN are male, and the mean age is 42 years; 72% are Asian, 15% are Black, and 11% are White, with 82% born outside of North America. The most common HBV genotype was B (39%); 745 of subjects were negative for the hepatitis B e antigen. The median serum level of HBV DNA when the study began was 3.6 log10 IU/mL; 68% of male subjects and 67% of female subjects had levels of alanine aminotransferase above the normal range. CONCLUSIONS: The HBRN cohort will be used to address important clinical and therapeutic questions for North Americans infected with chronic HBV and to guide health policies on HBV prevention and management in North America.

Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations are well-reported. Although sulfa prophylaxis generally is associated with DHPS mutant infection, whether mutant infection is associated with poorer clinical outcomes is less clear. The differing definitions of sulfa prophylaxis and the different mortality endpoints used in these studies may be one explanation for the conflicting study results. Applying different definitions of prophylaxis, mortality endpoints and DHPS mutant to 301 HIV-infected patients with Pneumocystis pneumonia, we demonstrate that prophylaxis, irrespective of definition, increased the risk of infection with pure mutant (any prophylaxis: AOR 4.00, 95% CI: 1.83-8.76, P < 0.001) but not mixed genotypes (any prophylaxis: AOR 0.78, 95% CI: 0.26-2.36, P = 0.65). However, infection with mutant DHPS, irrespective of definition, was not associated with increased mortality (all-cause or PCP death) at the three time-intervals examined (all P > 0.05). Future studies should standardize key variables associated with DHPS mutant infection as well as examine DHPS mutant subtypes (pure mutant vs. mixed infections) - perhaps even individual DHPS mutant genotypes - so that data can be pooled to better address this issue.

BACKGROUND: Smokers are exposed to significant doses of carcinogens, including tobacco-specific nitrosamines (TSNA). Previous studies have shown significant global differences in the levels of TSNAs in cigarette smoke because of the variation in tobacco blending and curing practices around the world. METHODS: Mouth-level exposure to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) measured in cigarette butts and urinary concentrations of its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) were examined among 126 daily smokers in four countries over a 24-hour study period. RESULTS: As mouth-level exposure of NNK increased, the urinary NNAL increased even after adjustment for other covariates (beta = 0.46, P = 0.004). The relationship between mouth-level exposure to nicotine and its salivary metabolite, cotinine, was not statistically significant (beta = 0.29, P = 0.057), likely because of the very limited range of differences in mouth-level nicotine exposure in this population. CONCLUSIONS: We have shown a direct association between the 24-hour mouth-level exposure of NNK resulting from cigarette smoking and the concentration of its primary metabolite, NNAL, in the urine of smokers. Internal dose concentrations of urinary NNAL are significantly lower in smokers in countries that have lower TSNA levels in cigarettes such as Canada and Australia in contrast to countries that have high levels of these carcinogens in cigarettes, such as the United States. Impact: Lowering the levels of NNK in the mainstream smoke of cigarettes through the use of specific tobacco types and known curing practices can significantly affect the exposure of smokers to this known carcinogen. (c)2010 AACR.