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Nirmatrelvir-ritonavir (Paxlovid), an oral antiviral treatment, is authorized for adults with mild-to-moderate COVID-19 who are at increased risk for progression to severe illness. However, real-world evidence on the benefit of Paxlovid, according to vaccination status, age group, and underlying health conditions, is limited. To examine the benefit of Paxlovid in adults aged ≥18 years in the United States, a large electronic health record (EHR) data set (Cosmos

Background Long-term symptoms following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are a major concern, yet their prevalence is poorly understood. Methods We conducted a prospective cohort study comparing adults with SARS-CoV-2 infection (coronavirus disease-positive [COVID+]) with adults who tested negative (COVID−), enrolled within 28 days of a Food and Drug Administration (FDA)-approved SARS-CoV-2 test result for active symptoms. Sociodemographic characteristics, symptoms of SARS-CoV-2 infection (assessed with the Centers for Disease Control and Prevention [CDC] Person Under Investigation Symptom List), and symptoms of post-infectious syndromes (ie, fatigue, sleep quality, muscle/joint pains, unrefreshing sleep, and dizziness/fainting, assessed with CDC Short Symptom Screener for myalgic encephalomyelitis/chronic fatigue syndrome) were assessed at baseline and 3 months via electronic surveys sent via text or email. Results Among the first 1000 participants, 722 were COVID+ and 278 were COVID−. Mean age was 41.5 (SD 15.2); 66.3% were female, 13.4% were Black, and 15.3% were Hispanic. At baseline, SARS-CoV-2 symptoms were more common in the COVID+ group than the COVID− group. At 3 months, SARS-CoV-2 symptoms declined in both groups, although were more prevalent in the COVID+ group: upper respiratory symptoms/head/eyes/ears/nose/throat (HEENT; 37.3% vs 20.9%), constitutional (28.8% vs 19.4%), musculoskeletal (19.5% vs 14.7%), pulmonary (17.6% vs 12.2%), cardiovascular (10.0% vs 7.2%), and gastrointestinal (8.7% vs 8.3%); only 50.2% and 73.3% reported no symptoms at all. Symptoms of post-infectious syndromes were similarly prevalent among the COVID+ and COVID− groups at 3 months. Conclusions Approximately half of COVID+ participants, as compared with one-quarter of COVID− participants, had at least 1 SARS-CoV-2 symptom at 3 months, highlighting the need for future work to distinguish long COVID. Clinical Trials Registration NCT04610515.

Background Antimicrobial resistance in nontyphoidal Salmonella (NTS) can limit treatment options. We assessed the contribution of international travel to antimicrobial-resistant NTS infections. Methods We describe NTS infections that were reported to the Foodborne Diseases Active Surveillance Network during 2018–2019 and screened for genetic resistance determinants, including those conferring decreased susceptibility to first-line agents (ciprofloxacin, ceftriaxone, or azithromycin). We used multivariable logistic regression to assess the association between resistance and international travel during the 7 days before illness began. We estimated the contribution of international travel to resistance using population-attributable fractions, and we examined reported antimicrobial use. Results Among 9301 NTS infections, 1159 (12%) occurred after recent international travel. Predicted resistance to first-line antimicrobials was more likely following travel; the adjusted odds ratio varied by travel region and was highest after travel to Asia (adjusted odds ratio, 7.2 [95% confidence interval, 5.5–9.5]). Overall, 19% (95% confidence interval, 17%–22%) of predicted resistance to first-line antimicrobials was attributable to international travel. More travelers than nontravelers receiving ciprofloxacin or other fluoroquinolones had isolates with predicted resistance to fluoroquinolones (29% vs 9%, respectively; P < .01). Conclusions International travel is a substantial risk factor for antimicrobial-resistant NTS infections. Understanding risks of resistant infection could help target prevention efforts.

Background Although most adults infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fully recover, a proportion have ongoing symptoms, or post-COVID conditions (PCC), after infection. The objective of this analysis was to estimate the number of United States (US) adults with activity-limiting PCC on 1 November 2021. Methods We modeled the prevalence of PCC using reported infections occurring from 1 February 2020 to 30 September 2021, and population-based, household survey data on new activity-limiting symptoms ≥1 month following SARS-CoV-2 infection. From these data sources, we estimated the number and proportion of US adults with activity-limiting PCC on 1 November 2021 as 95% uncertainty intervals, stratified by sex and age. Sensitivity analyses adjusted for underascertainment of infections and uncertainty about symptom duration. Results On 1 November 2021, at least 3.0–5.0 million US adults, or 1.2%–1.9% of the US adult population, were estimated to have activity-limiting PCC of ≥1 month’s duration. Population prevalence was higher in females (1.4%–2.2%) than males. The estimated prevalence after adjusting for underascertainment of infections was 1.7%–3.8%. Conclusions Millions of US adults were estimated to have activity-limiting PCC. These estimates can support future efforts to address the impact of PCC on the US population.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests have had limited recommended clinical application during the coronavirus disease 2019 (COVID-19) pandemic. To inform clinical practice, an understanding is needed of current perspectives of United States–based infectious disease (ID) physicians on the use, interpretation, and need for SARS-CoV-2 antibody tests.MethodsIn March 2022, members of the Emerging Infections Network (EIN), a national network of practicing ID physicians, were surveyed on types of SARS-CoV-2 antibody assays ordered, interpretation of test results, and clinical scenarios for which antibody tests were considered.ResultsOf 1867 active EIN members, 747 (40%) responded. Among the 583 who managed or consulted on COVID-19 patients, a majority (434/583 [75%]) had ordered SARS-CoV-2 antibody tests and were comfortable interpreting positive (452/578 [78%]) and negative (405/562 [72%]) results. Antibody tests were used for diagnosing post–COVID-19 conditions (61%), identifying prior SARS-CoV-2 infection (60%), and differentiating prior infection and response to COVID-19 vaccination (37%). Less than a third of respondents had used antibody tests to assess need for additional vaccines or risk stratification. Lack of sufficient evidence for use and nonstandardized assays were among the most common barriers for ordering tests. Respondents indicated that statements from professional societies and government agencies would influence their decision to order SARS-CoV-2 antibody tests for clinical decision making.ConclusionsPracticing ID physicians are using SARS-CoV-2 antibody tests, and there is an unmet need for clarifying the appropriate use of these tests in clinical practice. Professional societies and US government agencies can support clinicians in the community through the creation of appropriate guidance.

During September 2019, public health authorities in El Paso County, Colorado, were notified of four patients who had presented to nearby hospitals with clinical features consistent with botulism, a paralytic illness caused by botulinum neurotoxin. One patient died soon after presentation; the other three patients required intensive care but recovered after receiving botulism antitoxin. Botulinum toxin type A was detected in serum from all patients. On further investigation, all four patients had shared a meal that included commercially prepared roasted potatoes from an individual package without refrigeration instructions that had been left unrefrigerated for 15 d. Storage of the product at ambient temperature likely allowed botulism spores to produce botulinum toxin, resulting in severe illness and death. The manufacturer improved labeling in response to this outbreak. Public health officials should consider unrefrigerated potato products as a potential source of botulism; clinicians should consider botulism as a possible cause of paralytic illness.

Previous infection with SARS-CoV-2, the virus that causes COVID-19, has been estimated to confer up to 90% protection against reinfection, although this protection was lower against the Omicron variant compared with that against other SARS-CoV-2 variants (1-3). A test-negative design was used to estimate effectiveness of COVID-19 mRNA vaccines in preventing subsequent COVID-19-associated hospitalization among adults aged ≥18 years with a previous positive nucleic acid amplification test (NAAT) or diagnosis of COVID-19.

By November 30, 2021, approximately 130,781 COVID-19-associated deaths, one in six of all U.S. deaths from COVID-19, had occurred in California and New York.* COVID-19 vaccination protects against infection with SARS-CoV-2 (the virus that causes COVID-19), associated severe illness, and death (1,2); among those who survive, previous SARS-CoV-2 infection also confers protection against severe outcomes in the event of reinfection (3,4). The relative magnitude and duration of infection- and vaccine-derived protection, alone and together, can guide public health planning and epidemic forecasting. To examine the impact of primary COVID-19 vaccination and previous SARS-CoV-2 infection on COVID-19 incidence and hospitalization rates, statewide testing, surveillance, and COVID-19 immunization data from California and New York (which account for 18% of the U.S. population) were analyzed. Four cohorts of adults aged ≥18 years were considered: persons who were 1) unvaccinated with no previous laboratory-confirmed COVID-19 diagnosis, 2) vaccinated (14 days after completion of a primary COVID-19 vaccination series) with no previous COVID-19 diagnosis, 3) unvaccinated with a previous COVID-19 diagnosis, and 4) vaccinated with a previous COVID-19 diagnosis. Age-adjusted hazard rates of incident laboratory-confirmed COVID-19 cases in both states were compared among cohorts, and in California, hospitalizations during May 30-November 20, 2021, were also compared. During the study period, COVID-19 incidence in both states was highest among unvaccinated persons without a previous COVID-19 diagnosis compared with that among the other three groups. During the week beginning May 30, 2021, compared with COVID-19 case rates among unvaccinated persons without a previous COVID-19 diagnosis, COVID-19 case rates were 19.9-fold (California) and 18.4-fold (New York) lower among vaccinated persons without a previous diagnosis; 7.2-fold (California) and 9.9-fold lower (New York) among unvaccinated persons with a previous COVID-19 diagnosis; and 9.6-fold (California) and 8.5-fold lower (New York) among vaccinated persons with a previous COVID-19 diagnosis. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These relationships changed after the SARS-CoV-2 Delta variant became predominant (i.e., accounted for50% of sequenced isolates) in late June and July. By the week beginning October 3, compared with COVID-19 cases rates among unvaccinated persons without a previous COVID-19 diagnosis, case rates among vaccinated persons without a previous COVID-19 diagnosis were 6.2-fold (California) and 4.5-fold (New York) lower; rates were substantially lower among both groups with previous COVID-19 diagnoses, including 29.0-fold (California) and 14.7-fold lower (New York) among unvaccinated persons with a previous diagnosis, and 32.5-fold (California) and 19.8-fold lower (New York) among vaccinated persons with a previous diagnosis of COVID-19. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These results demonstrate that vaccination protects against COVID-19 and related hospitalization, and that surviving a previous infection protects against a reinfection and related hospitalization. Importantly, infection-derived protection was higher after the Delta variant became predominant, a time when vaccine-induced immunity for many persons declined because of immune evasion and immunologic waning (2,5,6). Similar cohort data accounting for booster doses needs to be assessed, as new variants, including Omicron, circulate. Although the epidemiology of COVID-19 might change with the emergence of new variants, vaccination remains the safest strategy to prevent SARS-CoV-2 infections and associated complications; all eligible persons should be up to date with COVID-19 vaccination. Additional recommendations for vaccine doses might be warranted in the future as the virus and immunity levels change.

Face masks have been recommended to reduce SARS-CoV-2 transmission. However, evidence of the individual benefit of face masks remains limited, including by vaccination status.As part of the COVID-19 Community Research Partnership cohort study, we performed a nested case-control analysis to assess the association between self-reported consistent mask use during contact with others outside the household and subsequent odds of symptomatic SARS-CoV-2 infection (COVID-19) during November 2020-October 2021. Using conditional logistic regression, we compared 359 case-participants to 3544 control-participants who were matched by date, adjusting for enrollment site, age group, sex, race/ethnicity, urban/rural county classification, and healthcare worker occupation.COVID-19 was associated with not consistently wearing a mask (adjusted odds ratio [aOR] 1.49; 95% confidence interval [CI] [1.14, 1.95]). Compared with persons ≥14 days after mRNA vaccination who also reported always wearing a mask, COVID-19 was associated with being unvaccinated (aOR 5.94; 95% CI [3.04, 11.62]), not wearing a mask (aOR 1.62; 95% CI [1.07, 2.47]), or both unvaccinated and not wearing a mask (aOR 9.07; 95% CI [4.81, 17.09]).Our findings indicate that consistent mask wearing can complement vaccination to reduce the risk of COVID-19.

Long-term sequelae after symptomatic SARS-CoV-2 infection may impact well-being, yet existing data primarily focus on discrete symptoms and/or health care use.To compare patient-reported outcomes of physical, mental, and social well-being among adults with symptomatic illness who received a positive vs negative test result for SARS-CoV-2 infection.This cohort study was a planned interim analysis of an ongoing multicenter prospective longitudinal registry study (the Innovative Support for Patients With SARS-CoV-2 Infections Registry [INSPIRE]). Participants were enrolled from December 11, 2020, to September 10, 2021, and comprised adults (aged ≥18 years) with acute symptoms suggestive of SARS-CoV-2 infection at the time of receipt of a SARS-CoV-2 test approved by the US Food and Drug Administration. The analysis included the first 1000 participants who completed baseline and 3-month follow-up surveys consisting of questions from the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29; 7 subscales, including physical function, anxiety, depression, fatigue, social participation, sleep disturbance, and pain interference) and the PROMIS Short Form-Cognitive Function 8a scale, for which population-normed T scores were reported.SARS-CoV-2 status (positive or negative test result) at enrollment.Mean PROMIS scores for participants with positive COVID-19 tests vs negative COVID-19 tests were compared descriptively and using multivariable regression analysis.Among 1000 participants, 722 (72.2%) received a positive COVID-19 result and 278 (27.8%) received a negative result; 406 of 998 participants (40.7%) were aged 18 to 34 years, 644 of 972 (66.3%) were female, 833 of 984 (84.7%) were non-Hispanic, and 685 of 974 (70.3%) were White. A total of 282 of 712 participants (39.6%) in the COVID-19-positive group and 147 of 275 participants (53.5%) in the COVID-19-negative group reported persistently poor physical, mental, or social well-being at 3-month follow-up. After adjustment, improvements in well-being were statistically and clinically greater for participants in the COVID-19-positive group vs the COVID-19-negative group only for social participation (β = 3.32; 95% CI, 1.84-4.80; P .001); changes in other well-being domains were not clinically different between groups. Improvements in well-being in the COVID-19-positive group were concentrated among participants aged 18 to 34 years (eg, social participation: β = 3.90; 95% CI, 1.75-6.05; P .001) and those who presented for COVID-19 testing in an ambulatory setting (eg, social participation: β = 4.16; 95% CI, 2.12-6.20; P .001).In this study, participants in both the COVID-19-positive and COVID-19-negative groups reported persistently poor physical, mental, or social well-being at 3-month follow-up. Although some individuals had clinically meaningful improvements over time, many reported moderate to severe impairments in well-being 3 months later. These results highlight the importance of including a control group of participants with negative COVID-19 results for comparison when examining the sequelae of COVID-19.

Summary Background The Gambia introduced seven-valent pneumococcal conjugate vaccine (PCV7) in August 2009, followed by PCV13 in May, 2011, using a schedule of three primary doses without a booster dose or catch-up immunisation. We aimed to assess the long-term impact of PCV on disease incidence. Methods We did 10 years of population-based surveillance for invasive pneumococcal disease (IPD) and WHO defined radiological pneumonia with consolidation in rural Gambia. The surveillance population included all Basse Health and Demographic Surveillance System residents aged 2 months or older. Nurses screened all outpatients and inpatients at all health facilities using standardised criteria for referral. Clinicians then applied criteria for patient investigation. We defined IPD as a compatible illness with isolation of Streptococcus pneumoniae from a normally sterile site (cerebrospinal fluid, blood, or pleural fluid). We compared disease incidence between baseline (May 12, 2008–May 11, 2010) and post-vaccine years (2016–2017), in children aged 2 months to 14 years, adjusting for changes in case ascertainment over time. Findings We identified 22 728 patients for investigation and detected 342 cases of IPD and 2623 cases of radiological pneumonia. Among children aged 2–59 months, IPD incidence declined from 184 cases per 100 000 person-years to 38 cases per 100 000 person-years, an 80% reduction (95% CI 69–87). Non-pneumococcal bacteraemia incidence did not change significantly over time (incidence rate ratio 0·88; 95% CI, 0·64–1·21). We detected zero cases of vaccine-type IPD in the 2–11 month age group in 2016–17. Incidence of radiological pneumonia decreased by 33% (95% CI 24–40), from 10·5 to 7·0 per 1000 person-years in the 2–59 month age group, while pneumonia hospitalisations declined by 27% (95% CI 22–31). In the 5–14 year age group, IPD incidence declined by 69% (95% CI −28 to 91) and radiological pneumonia by 27% (95% CI −5 to 49). Interpretation Routine introduction of PCV13 substantially reduced the incidence of childhood IPD and pneumonia in rural Gambia, including elimination of vaccine-type IPD in infants. Other low-income countries can expect substantial impact from the introduction of PCV13 using a schedule of three primary doses. Funding Gavi, The Vaccine Alliance; Bill & Melinda Gates Foundation; UK Medical Research Council; Pfizer Ltd.

Background During 2009‐2010, pandemic influenza A (H1N1) pdm09 virus (pH1N1) infections in England occurred in two epidemic waves. Reasons for a reported increase in case‐severity during the second wave are unclear. Methods We analysed hospital‐based surveillance for patients with pH1N1 infections in England during 2009‐2010 and linked national data sets to estimate ethnicity, socio‐economic status and death within 28 days of admission. We used multivariable logistic regression to assess whether changes in demographic, clinical and management characteristics of patients could explain an increase in ICU admission or death, and accounted for missing values using multiple imputation. Results During the first wave, 54/960 (6%) hospitalised patients required intensive care and 21/960 (2%) died; during the second wave 143/1420 (10%) required intensive care and 55/1420 (4%) died. In a multivariable model, during the second wave patients were less likely to be from an ethnic minority (OR 0.33, 95% CI 0.26‐0.42), have an elevated deprivation score (OR 0.75, 95% CI 0.68‐0.83), have known comorbidity (OR 0.78, 95% CI 0.63‐0.97) or receive antiviral therapy ≤2 days before onset (OR 0.72, 95% CI 0.56‐0.92). Increased case‐severity during the second wave was not explained by changes in demographic, clinical or management characteristics. Conclusions Monitoring changes in patient characteristics could help target interventions during multiple waves of COVID‐19 or a future influenza pandemic. To understand and respond to changes in case‐severity, surveillance is needed that includes additional factors such as admission thresholds and seasonal coinfections.

Although most adults infected with SARS-CoV-2 fully recover, a proportion have ongoing symptoms, or post-COVID conditions (PCC), after infection. The objective of this analysis was to estimate the number of US adults with activity-limiting PCC on November 1, 2021.We modeled the prevalence of PCC using reported infections occurring from February 1, 2020 - September 30, 2021, and population-based, household survey data on new activity-limiting symptoms ≥1 month following SARS-CoV-2 infection. From these data sources, we estimated the number and proportion of US adults with activity-limiting PCC on November 1, 2021, as 95% uncertainty intervals, stratified by sex and age. Sensitivity analyses adjusted for under-ascertainment of infections and uncertainty about symptom duration.On November 1, 2021, at least 3.0-5.0 million US adults were estimated to have activity-limiting PCC of ≥1 month duration, or 1.2%-1.9% of US adults. Population prevalence was higher in females (1.4%-2.2%) than males. The estimated prevalence after adjusting for under-ascertainment of infections was 1.7%-3.8%.Millions of US adults were estimated to have activity-limiting PCC. These estimates can support future efforts to address the impact of PCC on the U.S. population.

ObjectivesAlthough COVID-19 vaccines offer protection against infection and severe disease, there is limited information on the effect of vaccination on prolonged symptoms following COVID-19. Our objective was to determine differences in prevalence of prolonged symptoms 6 weeks after onset of COVID-19 among healthcare personnel (HCP) by vaccination status, and to assess differences in timing of return to work.DesignCohort analysis of HCP with COVID-19 enrolled in a multicentre vaccine effectiveness study. HCP with COVID-19 between December 2020 and August 2021 were followed up 6 weeks after illness onset.SettingHealth systems in 12 US states.ParticipantsHCP participating in a vaccine effectiveness study were eligible for inclusion if they had laboratory-confirmed symptomatic SARS-CoV-2 with mRNA vaccination (symptom onset ≥14 days after two doses) or no prior vaccination. Among 681 eligible participants, 419 (61%) completed a follow-up survey to assess symptoms reported 6 weeks after illness onset.ExposuresTwo doses of a COVID-19 mRNA vaccine compared with no COVID-19 vaccine.Main outcome measuresPrevalence of symptoms 6 weeks after onset of COVID-19 illness and days to return to work.ResultsAmong 419 HCP with COVID-19, 298 (71%) reported one or more COVID-like symptoms 6 weeks after illness onset, with a lower prevalence among vaccinated participants compared with unvaccinated participants (60.6% vs 79.1%; adjusted risk ratio 0.70, 95% CI 0.58 to 0.84). Following their illness, vaccinated HCP returned to work a median 2.0 days (95% CI 1.0 to 3.0) sooner than unvaccinated HCP (adjusted HR 1.37, 95% CI 1.04 to 1.79).ConclusionsReceipt of two doses of a COVID-19 mRNA vaccine among HCP with COVID-19 illness was associated with decreased prevalence of COVID-like symptoms at 6 weeks and earlier return to work.

In Alaska, while introduction of 13-valent pneumococcal conjugate vaccine led to declines in invasive pneumococcal disease, carriage prevalence remained stable because of replacement with non-vaccine serotypes. We assessed antibiotic non-susceptibility of carried pneumococci during serotype redistribution, determined the contributions of within-serotype shifts, and assessed factors that could explain changes in non-susceptibility.Each year from 2008 to 2015, at multiple sites in Alaska, we collected nasopharyngeal swabs and completed surveys for a convenience sample of participants. Pneumococcal serotyping and antimicrobial susceptibility testing for penicillin and erythromycin were performed. We described changes in non-susceptibility of isolates from 2008-2011 to 2012-2015, and assessed the contributions of serotype redistribution and within-serotype changes in non-susceptibility by comparing observed data to modeled data removing either factor. We used weighted logistic regression to assess whether reported risk factors could explain changes over time in non-susceptibility within serotypes.From 2008-2011 to 2012-2015, the overall proportion of isolates non-susceptible to penicillin or erythromycin increased by 3%, from 23% (n = 1,183) to 26% (n = 1,589; P 0.05). However, a decrease of 3% would be expected if serotype redistribution occurred without within-serotype changes in non-susceptibility. Standardization by either factor produced hypothetical data significantly different to observed data. Within serotypes, the average annual increase in odds of non-susceptibility to penicillin or erythromycin was 1.08 (95% CI 1.05-1.11). Recent antibiotic exposure, urban residence and increased household size of participants predicted isolate non-susceptibility but did not explain the increase over time.An overall increase in non-susceptibility of carried pneumococcal isolates to penicillin or erythromycin resulted from increases in non-susceptibility within serotypes, which outweighed a protective effect of serotype redistribution. Characterization of emerging resistant clones within carried non-vaccine serotypes, including risk factors for colonization and disease, would support disease prevention efforts and inform vaccine strategies.

Wearing a facemask can help to decrease the transmission of COVID-19. We investigated self-reported mask use among subjects aged 18 years and older participating in the COVID-19 Community Research Partnership (CRP), a prospective longitudinal COVID-19 surveillance study in the mid-Atlantic and southeastern United States. We included those participants who completed ≥5 daily surveys each month from December 1, 2020 through August 31, 2021. Mask use was defined as self-reported use of a face mask or face covering on every interaction with others outside the household within a distance of less than 6 feet. Participants were considered vaccinated if they reported receiving ≥1 COVID-19 vaccine dose. Participants (n = 17,522) were 91% non-Hispanic White, 68% female, median age 57 years, 26% healthcare workers, with 95% self-reported receiving ≥1 COVID-19 vaccine dose through August 2021; mean daily survey response was 85%. Mask use was higher among vaccinated than unvaccinated participants across the study period, regardless of the month of the first dose. Mask use remained relatively stable from December 2020 through April (range 71-80% unvaccinated; 86-93% vaccinated) and declined in both groups beginning in mid-May 2021 to 34% and 42% respectively in June 2021; mask use increased again since July 2021. Mask use by all was lower during weekends and on Christmas and Easter, regardless of vaccination status. Independent predictors of higher mask use were vaccination, age ≥65 years, female sex, racial or ethnic minority group, and healthcare worker occupation, whereas a history of self-reported prior COVID-19 illness was associated with lower use.

Background Inadequate prevention and treatment of malaria can lead to reinfections and recurrent episodes, and for vivax malaria, further recurrences from the dormant liver stage. This study quantified the impact of recurrent malaria episodes on morbidity and mortality. Methods Routinely collected data were available from 68,381 malaria patients presenting to the primary referral hospital in Papua, Indonesia. A multi-state modelling framework, with Cox regression for transition rates, was employed to determine the risks of re-presentation to hospital, receiving in-patient treatment, and early (≤14 days post treatment)/late death following multiple malaria episodes. Results The risk of re-presentation to hospital increased from 34.7% (95%CI: 34.4%–35.1%) at first episode to 58.6% (57.5%–59.6%) following the third episode. Infection with vivax malaria increased the rate of re-presentation to hospital by 1.48-fold (Hazard Ratio 1.48; 95%CI 1.44–1.51) and late hospital in-patient admission by 1.17-fold (1.11–1.22), compared to falciparum. Falciparum malaria caused a higher overall rate of early death (1.54 (1.25–1.92)), however, after multiple episodes, there was a trend towards a greater rate of early death for vivax infection (1.91 (0.73–4.97)). Conclusions Recurrent episodes of malaria can cause substantial morbidity and mortality, highlighting the importance of prevention and effective treatments for both falciparum and vivax malaria. Key messages To achieve elimination of malaria in South-East Asia, where prevalence of vivax malaria is high, we must prioritise the radical cure of vivax to eliminate the liver-stage of this species that causes relapses of infection.

Following increases in reported cases of hepatitis A, we assessed the impact of hepatitis A vaccine in Alaska Native persons. During 1996–2018, only 6 cases of hepatitis A were identified, all in unvaccinated adults. Populations can be protected against hepatitis A by achieving sufficient vaccination coverage over time.

In September 2018, CDC identified Salmonella enterica serotype Newport (Newport) infections that were multidrug resistant (MDR), with decreased susceptibility to azithromycin, a recommended oral treatment agent. Until 2017, decreased susceptibility to azithromycin had occurred in fewer than 0.5% of Salmonella isolates from U.S. residents. This report summarizes the investigation of a multistate MDR Salmonella outbreak conducted by CDC, state and local health departments, and the U.S. Department of Agriculture's Food Safety and Inspection Service. During June 2018-March 2019, 255 cases of infection with the outbreak strain were identified in 32 states; 43% of patients (89 of 206 with information on travel) reported recent travel to Mexico. Infections were linked to consumption of soft cheese obtained in Mexico and beef obtained in the United States. Consumers should avoid eating soft cheese that could be made from unpasteurized milk, regardless of the source of the cheese. When preparing beef, a food thermometer should be used to ensure that appropriate cooking temperatures are reached. When antibiotic treatment is needed for a patient, clinicians should choose antibiotics based on susceptibility testing wherever possible.

Background Haemophilus influenzae serotype a (Hia) can cause invasive disease similar to serotype b; no Hia vaccine is available. We describe the epidemiology of invasive Hia disease in the United States overall and specifically in Alaska during 2008–2017. Methods Active population- and laboratory-based surveillance for invasive Hia disease was conducted through Active Bacterial Core surveillance sites and from Alaska statewide invasive bacterial disease surveillance. Sterile-site isolates were serotyped via slide agglutination or real-time polymerase chain reaction. Incidences in cases per 100 000 were calculated. Results From 2008 to 2017, an estimated average of 306 invasive Hia disease cases occurred annually in the United States (estimated annual incidence: 0.10); incidence increased by an average of 11.1% annually. Overall, 42.7% of cases were in children aged Conclusions Incidence of invasive Hia disease has increased since 2008, with the highest burden among AI/AN children. These data can inform prevention strategies, including Hia vaccine development.

Background Antibiotic resistance in nontyphoidal Salmonella can limit treatment options for patients requiring antibiotic therapy. We assessed the contribution of international travel to resistance among nontyphoidal Salmonella infections. Methods We describe characteristics of nontyphoidal Salmonella infections in the Foodborne Diseases Active Surveillance Network during 2018 that were also reported to PulseNet and the National Antimicrobial Resistance Monitoring System. We defined genetic resistance to first-line antibiotics as the presence of genes or mutations known to confer decreased susceptibility or resistance to ciprofloxacin, azithromycin, or ceftriaxone. We used multivariable logistic regression to assess the association between resistance to first-line antibiotics and international travel in the 7 days before symptom onset overall and by United Nations statistical region, and we estimated the contribution of travel to resistance using population attributable fractions. Results Among 3,238 nontyphoidal Salmonella infections, 356 (11%) were in patients who traveled internationally in the 7 days before symptom onset. Of these, 109/356 (31%) had isolates with genetic resistance to first-line antibiotics, compared with 308/2882 (11%) non-travelers. Resistance was more likely following travel, after adjusting for age and sex (OR 3.7, 95% CI 2.9–4.8). Nine genes or mutations conferred resistance to first-line antibiotics among travel-associated isolates. The risk of resistance varied by region and was highest after travel to Asia (OR 7.5, 95% CI 4.7–12.0). Overall, 17.1% (95% CI 12.2%–21.7%) of genetic resistance to first-line antibiotics was attributable to international travel. Conclusion For patients with nontyphoidal Salmonella infections, international travel is associated with approximately three-fold increased risk that first-line agents could be ineffective. The estimated 17% of resistance to first-line antibiotics attributable to travel is encoded by relatively few genes and mutations. Investigation of the major sources of resistant strains could help target prevention efforts. Travel region should be considered when treating empirically; treatment should be adjusted based on results from antibiotic susceptibility testing. Disclosures All Authors: No reported disclosures

Background Shigella infection typically manifests as a self-limited gastrointestinal illness (shigellosis) and affects some populations disproportionately, including children, travelers, people experiencing homelessness, and men who have sex with men (MSM). Healthcare professionals (HCPs) are positioned to play an active role in the prevention and control of shigellosis but may not be aware of the multiple routes of Shigella transmission, risk factors, and prevention strategies. Methods Porter Novelli Public Services’ Fall DocStyles 2020 web-based survey was administered to HCPs in the United States to assess their clinical practice and knowledge about many health-related issues. Questions about acute diarrhea and shigellosis were completed by pediatricians, primary care physicians, nurse practitioners, and physician assistants. We analyzed responses to four questions related to Shigella transmission, risk factors, prevention, and barriers to patient education. Results Of the 2196 panelists contacted, 1503 were included (68% response rate). Most identified contaminated food and water as potential routes of Shigella transmission (84.9% and 78.8%, respectively), but substantially fewer recognized person-to-person contact (39.5%), fomite transmission (32.5%), or sexual activity (17.6%) as ways adults can become infected. Similarly, MSM were infrequently identified as being at risk for shigellosis (34.5%). Many HCPs reported counseling patients to wash hands and avoid food preparation when ill with Shigella (85.9% and 77.2%), but only 29.4% reported recommending avoiding sex. Only 7.1% of respondents correctly identified all routes of transmission, 21% identified all risk factors, and 22% identified all prevention strategies. Delay in diagnosis was the most frequently reported barrier to educating patients about shigellosis. Conclusion HCP knowledge of shigellosis is incomplete. Identified gaps in knowledge were related to MSM as an at-risk population and transmission of Shigella through fomites and person-to-person contact (including sexual contact). Informing HCPs about transmission, risk factors, and opportunities for prevention could improve recognition and stop the spread of shigellosis in vulnerable communities. Disclosures All Authors: No reported disclosures

Background Salmonella enterica I 4,[5],12:i:- is the 5th most common serotype causing clinical Salmonella infections in the United States. A strain with resistance to ampicillin, streptomycin, sulfamethoxazole, and tetracycline (ASSuT) has been linked to swine production in Europe and the United States. We reviewed U.S. surveillance data to describe clinical infections with antibiotic-resistant I 4,[5],12:i:-. Methods We reviewed data from CDC’s National Antimicrobial Resistance Monitoring System (NARMS) from 2009–2018 to describe trends. We analyzed whole-genome sequence data in PulseNet, the molecular surveillance network for foodborne illness in the United States, from 2015–2018 to distinguish between strains of I 4,[5],12:i:- using core-genome multilocus sequence typing, and identified antibiotic resistance determinants (ARDs). We reviewed data from the Foodborne Disease Outbreak Surveillance System to identify foods associated with outbreaks during 2009–2018. Results From 2009–2013 to 2014–2018, I 4,[5],12:i:- increased as a proportion of nontyphoidal Salmonella isolates in NARMS from 4.3% to 5.0% (P=0.006), while I 4,[5],12:i:- resistant to ASSuT increased from 1.1% to 2.6% (P< 0.001). Of the 3,056 sequenced I 4,[5],12:i:- isolates in PulseNet, 2,105 (69%) were in a clade within 0–108 alleles of each other (ASSuT clade). Within this clade, 77% of isolates had ARDs conferring resistance to ASSuT, compared with 3% outside the clade. Isolates in the clade were also more likely than those outside the clade to have ARDs conferring decreased susceptibility to ciprofloxacin (13.1% vs. 5.2%, P< 0.001) and resistance to ceftriaxone (5.4% vs. 2.3%, P< 0.001). Among I 4,[5],12:i:- outbreaks with a single food source, those related to the ASSuT clade were more often linked to pork (10/15 [67%] vs. 1/5 [20%], P=0.07). Conclusion The increase in I 4,[5],12:i:- infections during 2009–2018 was likely driven by a clade of which most members had resistance to ASSuT, and many had decreased susceptibility to antibiotics used for empiric treatment. The association of this strain with outbreaks linked to pork suggests that measures to decrease carriage of Salmonella and selection for this strain in swine could prevent clinical infections with multidrug resistant Salmonella I 4,[5],12:i-. Disclosures All Authors: No reported disclosures

Background An acute episode of malaria can be followed by multiple recurrent episodes either due to re-infection, recrudescence of a partially treated parasite or, in the case of Plasmodium vivax or P. ovale, relapse from the dormant liver stage of the parasite. The aim of this study was to quantify the impact of recurrent malaria episodes on morbidity and mortality in Papua, Indonesia. Methods We undertook a retrospective analysis of routinely collected data from malaria patients attending the primary referral hospital in Papua, Indonesia, between April 2004 and December 2013. Multi-state modelling was used to estimate the effect of recurring malaria episodes on re-presentation and admission to hospital and death. The risks of early (≤ 14 days) and late (15 to 365 days) hospital admission and death were estimated separately in our study to distinguish between the direct and indirect effects of malaria recurrence on adverse outcomes. Results A total of 68,361 patients were included in the analysis, of whom 37,168 (54.4%) presented initially with P. falciparum, 22,209 (32.5%) with P. vivax, and 8984 (13.1%) with other species. During 12 months of follow-up after each of the first four malaria episodes, 10,868 (15.9%) patients were admitted to hospital and 897 (1.3%) died. The risk of re-presenting to the hospital with malaria increased from 34.7% (95% CI 34.4%, 35.1%) at first episode to 58.6% (57.5%, 59.6%) following the third episode of malaria. After adjusting for co-factors, infection with P. vivax was a significant risk factor for re-presentation (hazard ratio (HR) = 1.48 (95% CI 1.44, 1.51)) and late admission to hospital (HR = 1.17 (1.11, 1.22)). Patients infected with P. falciparum had a greater overall rate of mortality within 14 days (HR = 1.54 (1.25, 1.92)), but after multiple episodes of malaria, there was a trend towards a higher rate of early death in patients infected with P. vivax compared to P. falciparum (HR = 1.91 (0.73, 4.97)). Conclusions Compared to patients initially infected with P. falciparum, those infected with P. vivax had significantly more re-presentations to hospital with malaria, and this contributed to a high risk of inpatient admission and death. These findings highlight the importance of radical cure of P. vivax to eliminate the dormant liver stages that trigger relapses.

Summary Background Little information is available about the effect of pneumococcal conjugate vaccines (PCVs) in low-income countries. We measured the effect of these vaccines on invasive pneumococcal disease in The Gambia where the 7-valent vaccine (PCV7) was introduced in August, 2009, followed by the 13-valent vaccine (PCV13) in May, 2011. Methods We conducted population-based surveillance for invasive pneumococcal disease in individuals aged 2 months and older who were residents of the Basse Health and Demographic Surveillance System (BHDSS) in the Upper River Region, The Gambia, using standardised criteria to identify and investigate patients. Surveillance was done between May, 2008, and December, 2014. We compared the incidence of invasive pneumococcal disease between baseline (May 12, 2008–May 11, 2010) and after the introduction of PCV13 (Jan 1, 2013–Dec 31, 2014), adjusting for changes in case ascertainment over time. Findings We investigated 14 650 patients, in whom we identified 320 cases of invasive pneumococcal disease. Compared with baseline, after the introduction of the PCV programme, the incidence of invasive pneumococcal disease decreased by 55% (95% CI 30–71) in the 2–23 months age group, from 253 to 113 per 100 000 population. This decrease was due to an 82% (95% CI 64–91) reduction in serotypes covered by the PCV13 vaccine. In the 2–4 years age group, the incidence of invasive pneumococcal disease decreased by 56% (95% CI 25–75), from 113 to 49 cases per 100 000, with a 68% (95% CI 39–83) reduction in PCV13 serotypes. The incidence of non-PCV13 serotypes in children aged 2–59 months increased by 47% (−21 to 275) from 28 to 41 per 100 000, with a broad range of serotypes. The incidence of non-pneumococcal bacteraemia varied little over time. Interpretation The Gambian PCV programme reduced the incidence of invasive pneumococcal disease in children aged 2–59 months by around 55%. Further surveillance is needed to ascertain the maximum effect of the vaccine in the 2–4 years and older age groups, and to monitor serotype replacement. Low-income and middle-income countries that introduce PCV13 can expect substantial reductions in invasive pneumococcal disease. Funding GAVI's Pneumococcal vaccines Accelerated Development and Introduction Plan (PneumoADIP), Bill & Melinda Gates Foundation, and the UK Medical Research Council.

We aimed to model the incidence of infection with Mycobacterium tuberculosis among adults using data on infection incidence in children, disease prevalence in adults, and social contact patterns. We conducted a cross-sectional face-to-face survey of adults in 2011, enumerating “close” (shared conversation) and “casual” (shared indoor space) social contacts in 16 Zambian communities and 8 South African communities. We modeled the incidence of M. tuberculosis infection in all age groups using these contact patterns, as well as the observed incidence of M. tuberculosis infection in children and the prevalence of tuberculosis disease in adults. A total of 3,528 adults participated in the study. The reported rates of close and casual contact were 4.9 per adult per day (95% confidence interval: 4.6, 5.2) and 10.4 per adult per day (95% confidence interval: 9.3, 11.6), respectively. Rates of close contact were higher for adults in larger households and rural areas. There was preferential mixing of close contacts within age groups and within sexes. The estimated incidence of M. tuberculosis infection in adults was 1.5–6 times higher (2.5%–10% per year) than that in children. More than 50% of infections in men, women, and children were estimated to be due to contact with adult men. We conclude that estimates of infection incidence based on surveys in children might underestimate incidence in adults. Most infections may be due to contact with adult men. Treatment and control of tuberculosis in men is critical to protecting men, women, and children from tuberculosis.

Background Multidrug-resistant (MDR) Shigella sonnei infections are a serious public health threat, and outbreaks are common among men who have sex with men (MSM). In February 2020, Australia’s Department of Health notified CDC of extensively drug-resistant (XDR) S. sonnei in 2 Australian residents linked to a cruise that departed from Florida. We describe an international outbreak of XDR S. sonnei and report on trends in MDR among S. sonnei in the United States. Methods Health departments (HDs) submit every 20th Shigella isolate to CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory for susceptibility testing. We defined MDR as decreased susceptibility to azithromycin (MIC ≥32 µg/mL) with resistance to ampicillin, ciprofloxacin, and cotrimoxazole, and XDR as MDR with additional resistance to ceftriaxone. We used PulseNet, the national subtyping network for enteric disease surveillance, to identify US isolates related to the Australian XDR isolates by short-read whole genome sequencing. We screened these isolates for resistance determinants (ResFinder v3.0) and plasmid replicons (PlasmidFinder) and obtained patient histories from HDs. We used long-read sequencing to generate closed plasmid sequences for 2 XDR isolates. Results NARMS tested 2,781 S. sonnei surveillance isolates during 2011–2018; 80 (2.9%) were MDR, including 1 (0.04%) that was XDR. MDR isolates were from men (87%), women (9%), and children (4%). MDR increased from 0% in 2011 to 15.3% in 2018 (Figure). In 2020, we identified XDR isolates from 3 US residents on the same cruise as the Australians. The US residents were 41–42 year-old men; 2 with available information were MSM. The US and Australian isolates were highly related (0–1 alleles). Short-read sequence data from all 3 US isolates mapped to the blaCTX-M-27 harboring IncFII plasmids from the 2 Australian isolates with >99% nucleotide identity. blaCTX-M-27 genes confer ceftriaxone resistance. Increase in Percentage of Shigella sonnei Isolates with Multidrug Resistance* in the United States, 2011–2018† Conclusion MDR S. sonnei is increasing and is most often identified among men. XDR S. sonnei infections are emerging and are resistant to all recommended antibiotics, making them difficult to treat without IV antibiotics. This outbreak illustrates the alarming capacity for XDR S. sonnei to disseminate globally among at-risk populations, such as MSM. Disclosures All Authors: No reported disclosures

BACKGROUND: Invasive infections from Haemophilus influenzae serotype a (Hia) have been reported with increasing frequency, especially among indigenous populations. However there are limited population-based-studies of clinical severity. We studied invasive Hia infections in Alaska to determine clinical characteristics, mortality, and sequelae. METHODS: We defined an invasive Hia infection as the first detection of Hia from a usually sterile site in a child

Background Azithromycin is a recommended oral agent for treating nontyphoidal Salmonella (NTS), when antibiotics are indicated. Azithromycin nonsusceptibility among NTS is Methods We classified isolates as the outbreak strain if they were within 11 alleles by core genome multilocus sequence typing. We defined a case as infection with the outbreak strain during June 2018–February 2019. After stratifying by gender and ethnicity, we compared food exposures ≤7 days before illness onset with those reported by healthy persons in the Foodborne Diseases Active Surveillance Network population survey (2006–2007). We used broth microdilution to determine antimicrobial susceptibility. Results We identified 218 case patients from 31 states; 49 of 176 (28%) were hospitalized and 2 died. Overall, 65% (121/187) were Hispanic, and 41% (70/169) visited Mexico in the 7 days before illness onset. Among travelers to Mexico, 71% (23/32) reported eating Mexican-style soft cheese; 16/23 (70%) recalled obtaining the cheese in Mexico. Among nontravelers, the proportion who ate Mexican-style soft cheese (30%, 18/60) was similar to that reported by healthy persons, whereas the proportion who consumed beef (91%, 60/66) was higher than reported by healthy persons (P = 0.04). The outbreak strain was detected in a sample of soft cheese obtained in Mexico, and in a cecal sample from a steer and a beef sample that was collected at FSIS-regulated establishments in the United States. Isolates were resistant to ampicillin and trimethoprim–sulfamethoxazole, nonsusceptible to azithromycin, and showed decreased susceptibility to ciprofloxacin. Conclusion This is the first documented outbreak of azithromycin-nonsusceptible Salmonella infections in the United States. Two food vehicles—soft cheese obtained in Mexico, and beef obtained in the United States—were epidemiologically and genetically associated with this outbreak. Further investigation is warranted to determine the routes of entry, prevalence, and spread of azithromycin-nonsusceptible Salmonella in US and Mexican cattle. Disclosures All Authors: No reported Disclosures.

Background Shigella spp. cause ~500,000 illnesses in the United States annually. Antibiotics are recommended for immunocompromised patients and shorten the duration of illness, thus limiting spread. First-line treatments include ciprofloxacin (CIP) and azithromycin (AZM). CIP resistance is a growing problem in the United States; decreased susceptibility to AZM (DSA) has been reported globally, particularly among men who have sex with men (MSM). We reviewed National Antimicrobial Resistance Monitoring System (NARMS) data to determine DSA trends among Shigella isolates in the United States. Methods Health departments nationwide forward every 20th Shigella isolate to CDC NARMS for antimicrobial susceptibility testing using broth microdilution. We defined CIP resistance using CLSI clinical breakpoints and DSA using epidemiological cutoff values where available. We performed whole genome sequencing on isolates from 2016 and screened the sequences for resistance determinants using ResFinder 3.0. Results To date, we have tested 3,044 Shigella isolates collected during 2011–2017. Overall, 264 isolates (9%) had DSA, increasing from 3% in 2011 to 23% in 2017; 41 (16%) were also CIP resistant. The odds of DSA increased by 1.5 (95% confidence interval [CI] 1.4–1.6) annually. DSA was more common among adult males (OR 21.2, CI 14.9–30.3), in isolates from the West census region (OR 2.4, CI 1.8–3.2), and in S. flexneri (OR 8.2, CI 6.3–10.7). Of 543 sequenced isolates, 52 (10%) had DSA; of these, 31 (60%) contained both mph(A) and erm(B) genes, 17 (33%) contained mph(A) only, and 4 (8%) had no identified macrolide-resistance mechanism. Conclusions In 2017, nearly 1 in 4 Shigella isolates tested had DSA, a 7-fold increase since 2011. This rapid rise in DSA parallels that seen in other countries, where resistance to other clinically relevant drugs is high and macrolides are no longer useful as empiric treatment. The increased risk of DSA in adult males is consistent with previous reports of DSA Shigella in MSM. The resistance genes observed are typically plasmid-mediated and can be transferred to other bacteria. Public health strategies to mitigate the spread of resistant Shigella should include antibiotic stewardship and novel approaches for sexually transmitted infection prevention in MSM. Disclosures All authors: No reported disclosures.

Summary Hepatitis A vaccine is recommended for children ≥1 year old to prevent hepatitis A virus (HAV) infection. However, the duration of vaccine-induced immunity is unknown. We evaluated a cohort of Alaska Native persons 20 years after HAV vaccination. Children aged 3-6 years had been previously randomized to receive three doses of HAV vaccine (360 ELISA units/dose) at: (i) 0,1,2 months; (ii) 0,1,6 months; and (iii) 0,1,12 months. We measured anti-HAV antibody concentrations every 2-3 years; described geometric mean concentrations (GMC) and the proportion with protective antibody (≥20 mIU mL-1) over time; and modelled the change in GMC using fractional polynomial regression. Of the 144 participants, after 20 years 52 (36.1%) were available for the follow-up (17, 18, 17 children in Groups A, B and C, respectively). Overall, 46 (88.5%) of 52 available participants had anti-HAV antibody concentrations ≥20 mIU mL-1, and overall GMC was 107 mIU mL-1. Although GMC levels were lower in Group A (60; CI 34-104) than in Group B (110; CI 68-177) or Group C (184; CI 98-345) (B vs C: P=.168; A vs B/C: P=.011), there was no difference between groups after adjusting for peak antibody levels post-vaccination (P=.579). Models predicted geometric mean concentrations of 124 mIU mL-1 after 25 years, and 106 mIU mL-1 after 30 years. HAV vaccine provides protective antibody levels 20 years after childhood vaccination. Lower antibody levels in Group A may be explained by a lower initial peak response. Our results suggest a booster vaccine dose is unnecessary for at least 25-30 years.

Background In high incidence settings, the majority of Mycobacterium tuberculosis (M.tb) transmission occurs outside the household. Little is known about where people’s indoor contacts occur outside the household, and how this differs between different settings. We estimate the number of contact hours that occur between adults and adult/youths and children in different building types in urban areas in Western Cape, South Africa, and Zambia. Methods Data were collected from 3206 adults using a cross-sectional survey, on buildings visited in a 24-h period, including building function, visit duration, and number of adults/youths and children (5–12 years) present. The mean numbers of contact hours per day by building function were calculated. Results Adults in Western Cape were more likely to visit workplaces, and less likely to visit shops and churches than adults in Zambia. Adults in Western Cape spent longer per visit in other homes and workplaces than adults in Zambia. More adults/youths were present at visits to shops and churches in Western Cape than in Zambia, and fewer at homes and hairdressers. More children were present at visits to shops in Western Cape than in Zambia, and fewer at schools and hairdressers. Overall numbers of adult/youth indoor contact hours were the same at both sites (35.4 and 37.6 h in Western Cape and Zambia respectively, p = 0.4). Child contact hours were higher in Zambia (16.0 vs 13.7 h, p = 0.03). Adult/youth and child contact hours were highest in workplaces in Western Cape and churches in Zambia. Compared to Zambia, adult contact hours in Western Cape were higher in workplaces (15.2 vs 8.0 h, p = 0.004), and lower in churches (3.7 vs 8.6 h, p = 0.002). Child contact hours were higher in other peoples’ homes (2.8 vs 1.6 h, p = 0.03) and workplaces (4.9 vs 2.1 h, p = 0.003), and lower in churches (2.5 vs 6.2, p = 0.004) and schools (0.4 vs 1.5, p = 0.01). Conclusions Patterns of indoor contact between adults and adults/youths and children differ between different sites in high M.tb incidence areas. Targeting public buildings with interventions to reduce M.tb transmission (e.g. increasing ventilation or UV irradiation) should be informed by local data. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1406-5) contains supplementary material, which is available to authorized users.

The South African Ministry of Health has proposed screening all clinic attendees for tuberculosis (TB). Amongst other factors, male sex and bar attendance are associated with higher TB risk. We show that 45% of adults surveyed in Western Cape attended a clinic within 6 months, and therefore potentially a relatively high proportion of the population could be reached through clinic-based screening. However, fewer than 20% of all men aged 18-25 years, or men aged 26-45 who attend bars, attended a clinic. The population-level impact of clinic-based screening may be reduced by low coverage among key risk groups.Le Ministère de la Santé d'Afrique du Sud a proposé de dépister la tuberculose (TB) chez tous les patients visitant un centre de santé. Parmi d'autres facteurs, le sexe masculin et la fréquentation des bars sont associés à un risque plus élevé de TB. Nous montrons que 45% des adultes dépistés dans la province du Cap Ouest s'étaient rendus dans un centre de santé au cours des 6 derniers mois et c'est pourquoi une proportion relativement élevée de la population pourrait être atteinte à travers un dépistage en centre de santé. Cependant, moins de 20% de tous les hommes âgés de 18–25 ans, ou des hommes âgés de 26–45 ans qui fréquentent les bars, se rendent dans un centre de santé. L'impact sur la population de ce type de dépistage pourrait donc être réduit par une faible couverture parmi les groupes à risque majeur.El Ministerio de Salud de Suráfrica propuso una detección sistemática de la tuberculosis (TB) a todas las personas que acudían a los consultorios. Entre los factores asociados con un mayor riesgo de padecer TB están el sexo masculino y la frecuentación de bares. El presente artículo pone de manifiesto que 45% de los adultos encuestados en la Ciudad del Cabo había acudido a un establecimiento de salud en los últimos 6 meses, por lo cual se pudo llegar a una proporción relativamente alta de la población mediante esta detección sistemática. Sin embargo, menos del 20% de todos los hombres entre los 18 y los 25 años, o entre los 26 y los 45 años de edad que frecuenta los bares, acudió a los establecimientos de salud. La repercusión a escala de la población de una detección sistemática realizada en los consultorios podría verse atenuada por una baja cobertura de los grupos más vulnerables.