BACKGROUND: To better establish the value of vaccination against influenza viruses, we estimated vaccine-averted influenza illnesses among young children and older adults in Chile, Guyana, and Paraguay. METHODS: We gathered country- and target population-specific data on monthly influenza hospitalizations, vaccine coverage, and vaccine effectiveness from surveillance records and immunization registries during 2013-2018. We applied a static compartmental model to estimate differences in the number influenza-associated respiratory disease events (symptomatic nonhospitalized illnesses, medically attended illnesses, hospitalizations) in the presence and absence of influenza vaccination programs. RESULTS: Between 2013 and 2018, vaccinating 68% of children aged 6-23 months in Chile averted an annual mean of 14 617 nonhospitalized, 9426 medically attended, and 328 hospitalized influenza illnesses; vaccinating 28% of children aged 6-23 months in Paraguay averted 1115 nonhospitalized, 719 medically attended, and 25 hospitalized influenza illnesses. Vaccinating 59% of older adults in Chile averted an annual mean of 83 429 nonhospitalized, 37 079 medically attended, and 1390 hospitalized influenza illnesses; vaccinating 36% of older adults in Paraguay averted an annual mean of 3932 nonhospitalized, 1748 medically attended, and 66 hospitalized influenza illnesses. In Guyana, a hypothetical campaign vaccinating 30% of children aged <5 years could have prevented an annual 1496 nonhospitalized, 971 medically attended, and 10 hospitalized influenza illnesses. Vaccinating 30% of adults aged ≥65 years could have prevented 568 nonhospitalized, 257 medically attended, and 10 hospitalized influenza illnesses. CONCLUSIONS: Influenza vaccination averted tens of thousands of illnesses and thousands of hospitalizations in Chile and Paraguay; influenza vaccination could have had a proportional benefit in Guyana.

Background: Annual estimates of seasonal influenza vaccine effectiveness can guide global risk communication and vaccination strategies to mitigate influenza-associated illness. We aimed to evaluate vaccine effectiveness in countries using the 2023 southern hemisphere influenza vaccine formulation.

Background: Vaccination is one of the most effective measures to prevent influenza illness and its complications. Since the 1980s, countries and territories in the Americas have progressively implemented influenza vaccination operations in high-risk priority groups—such as older adults, pregnant persons, persons with comorbidities and health workers. Methods: In this review, we present the history and progress of the seasonal influenza program in the Americas, how the program contributed to the efficient and timely roll-out of the COVID-19 vaccines during the pandemic, and how the program can be used to promote immunization operations across the life span for existing and future vaccines. Results: The influenza A(H1N1)pdm09 pandemic in 2009 and the COVID-19 pandemic in 2020–2023 underscored the importance of having a robust seasonal influenza vaccination program for pandemic preparedness and response. Overall, countries with existing seasonal influenza vaccination programs were better prepared and rolled out the delivery of COVID-19 vaccines more quickly and effectively compared to other countries where the influenza vaccination platform was weak or non-existent. Conclusions: Traditionally, national immunization programs of developing countries have been predominately focused on newborns, children younger than five years and school-aged children while often limiting their investment in effective adult vaccination programs; these programs are typically isolated to high-income countries. Countries in Latin America have been the exception, with strong influenza vaccination programs for adults regardless of national income level. The presence of functional and effective adult influenza vaccination programs can also facilitate the acceptance and uptake of other adult vaccines targeting priority groups at higher risk for severe illness or complications. © 2024 by the authors.

BACKGROUND: The 2023-2024 influenza season had predominant influenza A(H1N1)pdm09 virus activity, but A(H3N2) and B viruses co-circulated. Seasonal influenza vaccine strains were well-matched to these viruses. METHODS: Using health care encounters data from health systems in 8 states, we evaluated influenza vaccine effectiveness (VE) against influenza-associated medical encounters from October 2023-April 2024. Using a test-negative design, we compared the odds of vaccination between patients with an acute respiratory illness (ARI) who tested positive (cases) versus negative (controls) for influenza by molecular assay, adjusting for confounders. VE was stratified by age group, influenza type (overall, influenza A, influenza B), and care setting (hospitalization, emergency department or urgent care [ED/UC] encounter). RESULTS: Overall, 74,000 encounters in children and adolescents aged 6 months - 17 years (3,479 hospitalizations, 70,521 ED/UC encounters) and 267,606 in adults aged ≥18 years (66,828 hospitalizations, 200,778 ED/UC encounters) were included. Across care settings, among children and adolescents 15% (2,758/17,833) of cases versus 32% (18,240/56,167) of controls had received vaccination. Among adults, 25% (11,632/46,614) of cases versus 44% (97,811/220,992) of controls across care settings had received vaccination. VE was 58% (95% confidence interval [95% CI]: 44-69%) against hospitalization and 58% (95% CI: 56-60%) against ED/UC encounters for children and adolescents, and 39% (95% CI: 35-43) against hospitalization and 47% (95% CI: 46-49%) against ED/UC encounters for adults. Across age groups, VE was higher against influenza B than influenza A. CONCLUSIONS: Influenza vaccines provided protection against influenza-associated illness across health care settings and age groups during the 2023-2024 influenza season.

To reduce influenza-associated morbidity and mortality, countries in South America recommend annual influenza vaccination for persons at high risk for severe influenza illness, including young children, persons with preexisting health conditions, and older adults. Interim estimates of influenza vaccine effectiveness (VE) from Southern Hemisphere countries can provide early information about the protective effects of vaccination and help guide Northern Hemisphere countries in advance of their season. Using data from a multicountry network, investigators estimated interim VE against influenza-associated severe acute respiratory illness (SARI) hospitalization using a test-negative case-control design. During March 13-July 19, 2024, Argentina, Brazil, Chile, Paraguay, and Uruguay identified 11,751 influenza-associated SARI cases; on average, 21.3% of patients were vaccinated against influenza, and the adjusted VE against hospitalization was 34.5%. The adjusted VE against the predominating subtype A(H3N2) was 36.5% and against A(H1N1)pdm09 was 37.1%. These interim VE estimates suggest that although the proportion of hospitalized patients who were vaccinated was modest, vaccination with the Southern Hemisphere influenza vaccine significantly lowered the risk for hospitalization. Northern Hemisphere countries should, therefore, anticipate the need for robust influenza vaccination campaigns and early antiviral treatment to achieve optimal protection against influenza-associated complications.

In 2022, an estimated 5 million persons in the World Health Organization Region of the Americas (AMR) were living with chronic hepatitis B virus (HBV) infection, the leading cause of hepatocellular carcinoma and cirrhosis worldwide. Most chronic infections are acquired through mother-to-child transmission (MTCT) or horizontal transmission during childhood and are preventable with hepatitis B vaccination, including a birth dose (HepB-BD), followed by 2-3 additional doses (HepB3) in infancy. The Pan American Health Organization (PAHO) Elimination of MTCT of HBV infection strategy is intended to reduce chronic HBV infection (measured by hepatitis B surface antigen [HBsAg] seroprevalence) to ≤0.1% among children by achieving 1) ≥95% coverage with HepB-BD and HepB3; and 2) ≥80% of pregnant women received testing for HBsAg, and provision of hepatitis B immunoglobulin to HBV-exposed neonates. By 2012, all 51 AMR countries and territories (countries) provided HepB3 nationwide, and by 2021, 34 (67%) provided HepB-BD nationwide. Mathematical models estimate that HBsAg seroprevalence in children is ≤0.1% in 14 (28%) of 51 countries and at the regional level. Three (6%) of 51 countries met the 95% coverage targets for both HepB3 and HepB-BD during both 2021 and 2022. Of these, two have likely met criteria for the elimination of MTCT of HBV infection. However, in 2022, HepB3 coverage had declined by ≥10 percentage points in 15 (37%) of 41 countries with 2012 coverage data for comparison. These declines in HepB3 coverage, as well as the absence of HepB-BD in the routine immunization schedules in 17 countries, threaten PAHO's progress toward the elimination of MTCT of HBV infection. Efforts to introduce HepB-BD and maintain high HepB3 and HepB-BD coverage are needed.

HIV transmitted through cosmetic injection services via contaminated blood has not been previously documented. During summer 2018, the New Mexico Department of Health (NMDOH) was notified of a diagnosis of HIV infection in a woman with no known HIV risk factors who reported exposure to needles from cosmetic platelet-rich plasma microneedling facials (vampire facials) received at a spa in spring 2018. An investigation of the spa's services began in summer 2018, and NMDOH and CDC identified four former spa clients, and one sexual partner of a spa client, all of whom received HIV infection diagnoses during 2018-2023, despite low reported behavioral risks associated with HIV acquisition. Nucleotide sequence analysis revealed highly similar HIV strains among all cases. Although transmission of HIV via unsterile injection practices is a known risk, determining novel routes of HIV transmission among persons with no known HIV risk factors is important. This investigation identified an HIV cluster associated with receipt of cosmetic injection services at an unlicensed facility that did not follow recommended infection control procedures or maintain client records. Requiring adequate infection control practices and maintenance of client records at spa facilities offering cosmetic injection services can help prevent the transmission of HIV and other bloodborne pathogens and ensure adequate traceback and notification in the event of adverse clinical outcomes, respectively.

We conducted a large surveillance study among members of an integrated healthcare delivery system in Pacific Northwest of the United States to estimate medical costs attributable to medically attended acute gastroenteritis (MAAGE) on the day care was sought and during 30-day follow-up. We used multivariable regression to compare costs of MAAGE and non-MAAGE cases matched on age, gender, and index time. Differences accounted for confounders, including race, ethnicity, and history of chronic underlying conditions. Analyses included 73,140 MAAGE episodes from adults and 18,617 from children who were Kaiser Permanente Northwest members during 2014-2016. Total costs were higher for MAAGE cases relative to non-MAAGE comparators as were costs on the day care was sought and costs during follow-up. Costs of MAAGE are substantial relative to the cost of usual-care medical services, and much of the burden accrues during short-term follow-up.

BACKGROUND: Vaccine effectiveness (VE) is essential to monitor the performance of vaccines and generate strategic information to guide decision making. We pooled data from six Latin American countries to estimate the effectiveness of COVID-19 vaccines in preventing laboratory-confirmed SARS-CoV-2 hospitalisation during three different pandemic waves from February 2021 to September 2022. METHODS: We used a test-negative case-control design in hospitalised adults in Chile, Costa Rica, Ecuador, Guatemala, Paraguay, and Uruguay. We estimated adjusted VE by age group (18-64 and ≥65 years), vaccine type and product for primary series vaccination and booster vaccination and by time since last dose during the Omicron variant dominant period. We used mixed effects logistic regression models adjusting for sex, age, week of onset of symptom onset and pre-existing conditions with country fit as a random effect term. FINDINGS: We included 15,241 severe acute respiratory infection (SARI) patients in the analysis. Among adults 18-64 years, VE estimates for primary series vaccination during pre-Delta and Delta periods ranged by product from 66.5% to 95.1% and from 33.5% to 88.2% for older adults. During the Omicron period, VE estimates for primary series were lower and decreased by time since last vaccination, but VE increased to between 26.4% and 57.4% when a booster was administered. INTERPRETATION: mRNA and viral vector vaccines presented higher VE for both primary series and booster. While VE decreased over time, protection against severe COVID-19-associated hospitalisation increased when booster doses were administered. Vaccination with additional doses should be recommended, particularly for persons at increased risk of developing severe COVID-19. FUNDING: This work was supported by a grant from the U.S. Centers for Disease Control and Prevention (CDC) through cooperative agreements with the Pan American Health Organization/World Health Organization.

BACKGROUND: In the United States, public health surveillance systems often underestimate the burden of acute gastroenteritis (AGE) because they only identify disease among those who interact with the healthcare system. OBJECTIVE: To identify factors associated with healthcare-seeking behavior among individuals experiencing community-acquired AGE. METHODS: From October 2016 -September 2017, we conducted a weekly, age-stratified, random sample of Kaiser Permanente Northwest members located in northwest Oregon and southwest Washington, United States. Individuals who completed the online survey and experienced AGE were included in the analysis. Univariate and multivariable logistic regressions were performed to identify predictors of healthcare-seeking behavior. RESULTS: Of the 3,894 survey respondents, 395 experienced an AGE episode and were eligible for analysis, of whom, 82 (21%) sought care for their AGE episode. In the final multivariable model, individuals with a concurrent fever (odds ratio [OR]: 4.76, 95% confidence interval [95% CI]: 2.48-9.13), increased diarrhea duration (≥6 days vs 1-4 days, OR: 4.22, 95% CI: 1.78-10.03), or increased vomiting duration (≥3 days vs 1 days, OR: 2.97, 95% CI: 1.22-7.26), were significantly more likely to seek healthcare. In the adjusted model, no sociodemographic or chronic disease variables were associated with healthcare-seeking behavior. CONCLUSION: These findings suggest that individuals with a short duration of AGE and those without concurrent fever are underrepresented in healthcare facility-based surveillance systems.

What is already known about this topic? | | Effectiveness of seasonal influenza vaccine varies by season and circulating virus type. | | What is added by this report? | | The 2023 Southern Hemisphere seasonal influenza vaccine reduced the risk for influenza-associated hospitalizations by 52%. Circulating influenza viruses were genetically similar to those targeted by the 2023–24 Northern Hemisphere influenza vaccine formulation. This vaccine might offer similar protection if these viruses predominate during the coming Northern Hemisphere influenza season. | | What are the implications for public health practice? | | Vaccination remains one of the most effective ways to protect against influenza-associated complications. In anticipation of Northern Hemisphere influenza virus circulation, CDC recommends that health authorities encourage U.S. health care providers to administer seasonal influenza vaccine to all eligible persons aged ≥6 months.

In May 2021, an agricultural worker originally from Trementinal, Argentina, sought treatment for febrile illness in Tarija, Bolivia, where he resided at the time of illness onset. The patient tested negative for hantavirus RNA, but next-generation sequencing of a serum sample yielded a complete genome for Rio Negro virus.

Nipah virus (NiV), an emerging zoonotic pathogen in Southeast Asia, is transmitted from Pteropus species of fruit bats to a wide range of species, including humans, pigs, horses, dogs, and cats. NiV has killed millions of animals and caused highly fatal human outbreaks since no vaccine is commercially available. This study characterized the immunogenicity and safety of poxvirus-based Nipah vaccines that can be used in humans and species responsible for NiV transmission. Mice were vaccinated with modified vaccinia Ankara (MVA) and raccoon pox (RCN) viral vectors expressing the NiV fusion (F) and glycoprotein (G) proteins subcutaneously (SC) and intranasally (IN). Importantly, both vaccines did not induce significant weight loss or clinical signs of disease while generating high circulating neutralizing antibodies and lung-specific IgG and IgA responses. The MVA vaccine saw high phenotypic expression of effector and tissue resident memory CD8ɑ(+) T cells in lungs and splenocytes along with the expression of central memory CD8ɑ(+) T cells in lungs. The RCN vaccine generated effector memory (SC) and tissue resident (IN) CD8ɑ(+) T cells in splenocytes and tissue resident (IN) CD8ɑ(+) T cells in lung cells. These findings support MVA-FG and RCN-FG viral vectors as promising vaccine candidates to protect humans, domestic animals, and wildlife from fatal disease outcomes and to reduce the global threat of NiV.

BACKGROUND: Vaccination is one of the most effective measures to prevent influenza illness and its complications; influenza vaccination remained important during the COVID-19 pandemic to prevent additional burden on health systems strained by COVID-19 demand. OBJECTIVES: We describe policies, coverage, and progress of seasonal influenza vaccination programs in the Americas during 2019-2021 and discuss challenges in monitoring and maintaining influenza vaccination coverage among target groups during the COVID-19 pandemic. METHODS: We used data on influenza vaccination policies and vaccination coverage reported by countries/territories via the electronic Joint Reporting Form on Immunization (eJRF) for 2019-2021. We also summarized country vaccination strategies shared with PAHO. RESULTS: As of 2021, 39 (89 %) out of 44 reporting countries/territories in the Americas had policies for seasonal influenza vaccination. Countries/territories adapted health services and immunization delivery strategies using innovative approaches, such as new vaccination sites and expanded schedules, to ensure continuation of influenza vaccination during the COVID-19 pandemic. However, among countries/territories that reported data to eJRF in both 2019 and 2021, median coverage decreased; the percentage point decrease was 21 % (IQR = 0-38 %; n = 13) for healthcare workers, 10 % (IQR = -1.5-38 %; n = 12) for older adults, 21 % (IQR = 5-31 %; n = 13) for pregnant women, 13 % (IQR = 4.8-20.8 %; n = 8) for persons with chronic diseases, and 9 % (IQR = 3-27 %; n = 15) for children. CONCLUSIONS: Countries/territories in the Americas successfully adapted influenza vaccination delivery to continue vaccination services during the COVID-19 pandemic; however, reported influenza vaccination coverage decreased from 2019 to 2021. Reversing declines in vaccination will necessitate strategic approaches that prioritize sustainable vaccination programs across the life course. Efforts should be made to improve the completeness and quality of administrative coverage data. Lessons learned from COVID-19 vaccination, such as the rapid development of electronic vaccination registries and digital certificates, might facilitate advances in coverage estimation.

OBJECTIVE: To estimate the 2022 end-of-season influenza vaccine effectiveness (VE) against severe acute respiratory illness (SARI) hospitalization in Chile, Paraguay, and Uruguay. METHODS: We pooled surveillance data from SARI cases in 18 sentinel surveillance hospitals in Chile (n=9), Paraguay (n=2), and Uruguay (n=7) during March 16-November 30, 2022. VE was estimated using a test-negative design and logistic regression models adjusted for country, age, sex, presence of ≥1 comorbidity, and week of illness onset. VE estimates were stratified by influenza virus type and subtype (when available) and influenza vaccine target population, categorized as children, individuals with comorbidities, and older adults, defined per countries' national immunization policies. RESULTS: Among the 3,147 SARI cases, there were 382 (12.1%) influenza test-positive case-patients; 328 (85.9%) influenza case-patients were in Chile, 33 (8.6%) were in Paraguay, and 21 (5.5%) were in Uruguay. In all countries, the predominant subtype was influenza A(H3N2) (92.6% of influenza cases). Adjusted VE against any influenza-associated SARI hospitalization was 33.8% (95% CI: 15.3%, 48.2%); VE against influenza A(H3N2)-associated SARI hospitalization was 30.4% (95% CI: 10.1%, 46.0%). VE estimates were similar across target populations. CONCLUSION: During the 2022 influenza season, influenza vaccination reduced the odds of hospitalization among those vaccinated by one-third. Health officials should encourage influenza vaccination in accordance with national recommendations.

Introduction This paper describes the epidemiology and clinical presentation of complex regional pain syndrome (CRPS) in a large, integrated health care delivery system; and CRPS incidence rates (IRs) over a time period spanning human papillomavirus (HPV) vaccine licensure and published case reports of CRPS following HPV vaccination. Methods The authors examined CRPS diagnoses in patients aged 9-30 years between January 2002 and December 2017 using electronic medical records, excluding patients with lower limb diagnoses only. Medical record abstraction and adjudication were conducted to verify diagnoses and describe clinical characteristics. CRPS IRs were calculated for 3 periods: Period 1 (2002-2006: before HPV vaccine licensure), Period 2 (2007-2012: after licensure but before published case reports), and Period 3 (2013-2017: after published case reports). Results A total of 231 individuals received an upper limb or unspecified CRPS diagnosis code during the study period; 113 cases were verified through abstraction and adjudication. Most verified cases (73%) were associated with a clear precipitating event (eg, non-vaccine-related injury, surgical procedure). The authors identified only 1 case in which a practitioner attributed CRPS onset to HPV vaccination. Twenty-five incident cases occurred in Period 1 (IR = 4.35/100,000 person-years (PY), 95% confidence interval (CI) = 2.94-6.44), 42 in Period 2 (IR = 5.94/100,000 PY, 95% CI = 4.39-8.04), and 29 in Period 3 (IR = 4.53/100,000 PY, 95% CI = 3.15-6.52); differences between periods were not statistically significant. Conclusion These data provide a comprehensive assessment of the epidemiology and characteristics of CRPS in children and young adults and provide further reassurance about the safety of HPV vaccination.

BACKGROUND: There is limited information about how on-line screening tools developed by integrated systems facilitated management of COVID-like illness patients. METHODS: Using the Kaiser Permanente Northwest (KPNW) Electronic Health Record, we identified adult plan members who accessed online COVID-19 screening e-visits and enumerated their subsequent medical encounters, tests for SARS-CoV-2, and test outcomes. RESULTS: Between May 2020 and December 2021, members completed 55,139 e-visits, with disproportionate representation among females (65% vs. 53% in the overall membership) and members aged <45 years (61% vs. 39%). Thirty percent of patients (16,953) were managed entirely through e-visits and 70% received subsequent in-person care. The percent of SARS-CoV-2 positive individuals was highest among the 1055 individuals triaged to inpatient care (17.9%), compared to 9.5% among those escalated to additional ambulatory care. CONCLUSIONS: The e-visit on-line screening tool helped KPNW assist thousands of patients with COVID-19 symptoms, avoid unnecessary in-person patient encounters, and preserved KPNW infection control and pandemic surge capacity.

BACKGROUND: With the potential impact of the COVID-19 pandemic on HIV preexposure prophylaxis (PrEP) care management, we assessed the number of PrEP users and sexually transmitted infection (STI) testing-eligible PrEP users, STI testing rates, and prevalence between prepandemic (January 1, 2018-March 31, 2020) and early-pandemic (April 1, 2020-September 30, 2020) periods. METHODS: In this retrospective cohort study, a PrEP user for a given quarter is defined as either a previous PrEP user or a PrEP initiator who has at least 1-day coverage of tenofovir/emtricitabine in the given quarter. The STI testing-eligible PrEP users for a given quarter were defined as those persons whose runout date (previous dispense date + days of tenofovir/emtricitabine supply) was in the given quarter. RESULTS: The quarterly number of PrEP users increased from the first quarter of 2018 to the first quarter of 2020 and then decreased in the second and third quarter of 2020. Among STI testing-eligible PrEP users who had ≤14 days between runout and next refill date, gonorrhea and chlamydia screening testing rates were 95.1% for prepandemic and 93.4% for early pandemic ( P = 0.1011). Among all STI testing-eligible PrEP users who were tested for gonorrhea and chlamydia, gonorrhea prevalence was 6.7% for prepandemic and 5.7% for early pandemic ( P = 0.3096), and chlamydia prevalence was 7.0% for prepandemic and 5.8% for early pandemic ( P = 0.2158). CONCLUSIONS: Although the early COVID-19 pandemic resulted in lower numbers of PrEP users and PrEP initiators, individuals who remained continuous users of PrEP maintained extremely high rates of bacterial STI screening. With high STI prevalence among PrEP users, assessments of PrEP care management are continuously needed.

Knowledge of the epidemiology of sporadic acute gastroenteritis (AGE) in the United States is limited. During September 2016-September 2017, we surveyed Kaiser Permanente Northwest members in Oregon and Washington, USA, to collect data on the 30-day prevalence of dually defined AGE and diarrhea disease and related health-seeking behavior; from a subset of participants, we obtained a stool specimen. Using the iterative proportional fitting algorithm with raked weights, we generated AGE prevalence and annualized rate estimates. We detected norovirus, rotavirus, astrovirus, and sapovirus from submitted stool specimens through real-time quantitative reverse transcription PCR (qRT-PCR). We estimated a 30-day prevalence of 10.4% for AGE and 7.6% for diarrhea only; annual rates were 1.27 cases/person/year for AGE and 0.92 cases/person/year for diarrhea only. Of those with AGE, 19% sought medical care. Almost one quarter (22.4%) of stool specimens from those reporting AGE tested positive for ≥1 viral pathogen, compared with 8.2% from those without AGE.

We assessed rotavirus vaccine impact using data on acute gastroenteritis (AGE) encounters within an integrated healthcare delivery system during 2000 - 2018. Following rotavirus vaccine introduction, all-cause AGE rates among children <5 years declined by 36% (95% CI: 32-40%) for outpatient and 54% (95% CI: 46-60%) for inpatient encounters.

BACKGROUND: Initial and follow-up sexually transmitted infection (STI) and HIV testing is recommended when taking HIV preexposure prophylaxis (PrEP). We assessed STI services before and after PrEP initiation among persons aged ≥18 years. METHODS: We conducted this retrospective cohort study at an US integrated healthcare delivery system. We measured HIV/STI testing rates, STI prevalence and treatment at 3 time points: (1) at PrEP initiation, (2) at 120 days, and (3) at 210 days. RESULTS: Of 685 PrEP initiators, 67.2% continued PrEP use at 120 days and 49.5% at 210 days. Of PrEP users, HIV and STI testing were > 85% and > 80%, respectively, at all 3 time points. Prevalence for any chlamydia, rectal chlamydia, and any gonorrhea, rectal gonorrhea, or pharyngeal gonorrhea was always high at the 120 days and 210 days (e.g, 6.9%, 10.5%, 6.7%, 5.0%, and 5.2%, respectively, at the 120-days for continuous PrEP users). Over 90% of all individuals who tested positive for chlamydia and/or gonorrhea received antibiotic pharmacy fills within seven days at 120 days and 210 days. Monthly PrEP-related pharmacy cost was about $2259-$2659. The proportion of the total medical cost that was PrEP-related pharmacy was about 82% for PrEP continuous users. CONCLUSIONS: Although HIV/STI testing rates were high, they can still be improved during HIV PrEP management. High STI prevalence after PrEP initiation in this study suggests that patients taking PrEP are at risk of acquiring an STI. Interventions to improve STI services during PrEP management are continuously needed.

Population-based rates of infection with SARS-CoV-2 (the virus that causes COVID-19) and related health care utilization help determine estimates of COVID-19 vaccine effectiveness and averted illnesses, especially since the SARS-CoV-2 B.1.617.2 (Delta) variant began circulating in June 2021. Among members aged ≥12 years of a large integrated health care delivery system in Oregon and Washington, incidence of laboratory-confirmed SARS-CoV-2 infection, emergency department (ED) visits, and hospitalizations were calculated by COVID-19 vaccination status, vaccine product, age, race, and ethnicity. Infection after full vaccination was defined as a positive SARS-CoV-2 molecular test result ≥14 days after completion of an authorized COVID-19 vaccination series.* During the July-September 2021 surveillance period, SARS-CoV-2 infection occurred among 4,146 of 137,616 unvaccinated persons (30.1 per 1,000 persons) and 3,009 of 344,848 fully vaccinated persons (8.7 per 1,000). Incidence was higher among unvaccinated persons than among vaccinated persons across all demographic strata. Unvaccinated persons with SARS-CoV-2 infection were more than twice as likely to receive ED care (18.5%) or to be hospitalized (9.0%) than were vaccinated persons with COVID-19 (8.1% and 3.9%, respectively). The crude mortality rate was also higher among unvaccinated patients (0.43 per 1,000) than in fully vaccinated patients (0.06 per 1,000). These data support CDC recommendations for COVID-19 vaccination, including additional and booster doses, to protect individual persons and communities against COVID-19, including illness and hospitalization caused by the Delta variant (1).

The Abbott BinaxNOW rapid antigen test is cheaper and faster than real-time reverse transcription PCR (rRT-PCR) for detecting severe acute respiratory syndrome coronavirus 2. We compared BinaxNOW with rRT-PCR in 769 paired specimens from 342 persons during a coronavirus disease outbreak among horse racetrack workers in California, USA. We found positive percent agreement was 43.3% (95% CI 34.6%-52.4%), negative percent agreement 100% (95% CI 99.4%-100%), positive predictive value 100% (95% CI 93.5%-100%), and negative predictive value 89.9% (95% CI 87.5%-92.0%). Among 127 rRT-PCR-positive specimens, the 55 with paired BinaxNOW-positive results had a lower mean cycle threshold than the 72 with paired BinaxNOW-negative results (17.8 vs. 28.5; p<0.001). Of 100 specimens with cycle threshold <30, a total of 51 resulted in positive virus isolation; 45 (88.2%) of those were BinaxNOW-positive. Our comparison supports immediate isolation for BinaxNOW-positive persons and confirmatory testing for negative persons.

BACKGROUND: Acute gastroenteritis (AGE) causes a substantial burden in the United States, but its etiology frequently remains undetermined. Active surveillance within an integrated healthcare delivery system was used to estimate the prevalence and incidence of medically attended norovirus, rotavirus, sapovirus, and astrovirus. METHODS: Active surveillance was conducted among all enrolled members of Kaiser Permanente Northwest during July 2014 - June 2016. An age-stratified, representative sample of AGE-associated medical encounters were recruited to provide a stool specimen to be tested for norovirus, rotavirus, sapovirus, and astrovirus. Medically attended AGE (MAAGE) encounters for a patient occurring within 30 days were grouped into one episode, and all-cause MAAGE incidence was calculated. Pathogen- and healthcare setting-specific incidence estimates were calculated using age-stratified bootstrapping. RESULTS: The overall incidence of MAAGE was 40.6 episodes per 1000 person-years (PY), with most episodes requiring no more than outpatient care. Norovirus was the most frequently detected pathogen, with an incidence of 5.5 medically attended episodes per 1000 PY. Incidence of norovirus MAAGE was highest among children aged <5 years (20.4 episodes per 1000 PY), followed by adults aged ≥65 years (4.5 episodes per 1000 PY). Other study pathogens showed similar patterns by age, but lower overall incidence (sapovirus: 2.4 per 1000 PY, astrovirus: 1.3 per 1000 PY, rotavirus: 0.5 per 1000 PY). CONCLUSIONS: Viral enteropathogens, particularly norovirus, are an important contributor to MAAGE, especially among children <5 years of age. The present findings underline the importance of judicious antibiotics use for pediatric AGE and suggest that an effective norovirus vaccine could substantially reduce MAAGE.

BACKGROUND: Acute gastroenteritis (AGE) causes a substantial burden in the United States, but its etiology frequently remains undetermined. Active surveillance within an integrated healthcare delivery system was used to estimate the prevalence and incidence of medically attended norovirus, rotavirus, sapovirus, and astrovirus. METHODS: Active surveillance was conducted among all enrolled members of Kaiser Permanente Northwest during July 2014 - June 2016. An age-stratified, representative sample of AGE-associated medical encounters were recruited to provide a stool specimen to be tested for norovirus, rotavirus, sapovirus, and astrovirus. Medically attended AGE (MAAGE) encounters for a patient occurring within 30 days were grouped into one episode, and all-cause MAAGE incidence was calculated. Pathogen- and healthcare setting-specific incidence estimates were calculated using age-stratified bootstrapping. RESULTS: The overall incidence of MAAGE was 40.6 episodes per 1000 person-years (PY), with most episodes requiring no more than outpatient care. Norovirus was the most frequently detected pathogen, with an incidence of 5.5 medically attended episodes per 1000 PY. Incidence of norovirus MAAGE was highest among children aged <5 years (20.4 episodes per 1000 PY), followed by adults aged 65 years (4.5 episodes per 1000 PY). Other study pathogens showed similar patterns by age, but lower overall incidence (sapovirus: 2.4 per 1000 PY, astrovirus: 1.3 per 1000 PY, rotavirus: 0.5 per 1000 PY). CONCLUSIONS: Viral enteropathogens, particularly norovirus, are an important contributor to MAAGE, especially among children <5 years of age. The present findings underline the importance of judicious antibiotics use for pediatric AGE and suggest that an effective norovirus vaccine could substantially reduce MAAGE.

The current context of malaria elimination requires urgent development and implementation of highly sensitive and specific methods for prompt detection and treatment of malaria parasites. Such methods should overcome current delays in diagnosis, allow the detection of low-density infections and address the difficulties in accessing remote endemic communities. In this study, we assessed the performance of the RealAmp and malachite-green loop mediated isothermal amplification (MG-LAMP) methodologies, using microscopy and conventional nested-PCR as reference techniques. Both LAMP techniques were performed for Plasmodium genus, P. falciparum, and P. vivax identification using 136 whole blood samples collected from three communities located in the Peruvian Amazon basin. Turnaround time and costs of performing the LAMP assays were estimated and compared to that of microscopy and nested-PCR. Using nested-PCR as reference standard, we calculated the sensitivity, specificity and 95% confidence interval (CI) for all methods. RealAmp had a sensitivity of 92% (95% CI: 85-96.5%) and specificity of 100% (95% CI: 89.1-100%) for species detection; sensitivity and specificity of MG-LAMP were 94% (95% CI: 87.5-97.8%) and 100% (89.1-100%), respectively. Whereas microscopy showed 88.1% sensitivity (95% CI: 80.2-93.7%) and 100% specificity (95%: 89.1-100%). The turnaround time and costs of performing the LAMP assays were lower compared to those associated with nested-PCR but higher than those associated with microscopy. The two LAMP assays were shown to be more sensitive and simple to implement than microscopy. Both LAMP methodologies could be used as large-scale screening tests, but the MG-LAMP assay uses a simple, portable heat-block while the RealAmp requires a RealAmp machine or a real-time PCR machine. This makes the MG-LAMP an appropriate choice for malaria surveillance studies in endemic sites. Use of LAMP tests in active case detection of Plasmodium parasites could help to detect positive malaria cases early.

BACKGROUND: Rotavirus is a common cause of severe pediatric acute gastroenteritis (AGE). Two vaccines are licensed in the United States and have demonstrated high effectiveness against moderate to severe disease. However, fewer data are available on rotavirus vaccine effectiveness (VE) against milder disease. METHODS: We leveraged active surveillance data from Kaiser Permanente Northwest (KPNW) to calculate rotavirus VE against medically attended rotavirus illness among age-eligible children. We utilized a test-negative case-control design and applied 4 distinct case definitions based on reverse-transcription-quantitative real-time PCR (qRT-PCR) assay and enzyme immunoassay (EIA) test results. VE was calculated as 100*(1 - Odds Ratio), and models were adjusted for age group. RESULTS: The VE analysis population comprised 842 children, 799 (95%) of which had mild disease requiring at most a clinic visit, and 698 (83%) of whom were fully vaccinated against rotavirus. Age-adjusted VE was 70% (95% confidence interval [CI]: 37 - 86%) against disease defined solely by qRT-PCR results, 72% (95% CI: 31 - 89%) against disease as defined by qRT-PCR with a quantification cycle (Cq) value <27, 73% (95% CI: 32 - 90%) against disease that was qRT-PCR positive but EIA negative, and 62% (95% CI: -20 - 88%) against disease defined solely by EIA. Results were similar when restricting to disease resulting in at most an ambulatory clinic or emergency department visit. CONCLUSIONS: These results support the effectiveness of rotavirus vaccination in protecting U.S. children from mild to moderate as well as severe disease. Our findings are also useful to show the effectiveness of rotavirus vaccination against qRT-PCR-defined illness.

Refugees are an often understudied population and vulnerable to poor health outcomes. No large-scale analyses have evaluated the prevalence of overweight and obesity in US-bound refugees. Using data obtained from the Centers for Disease Control (CDC) Electronic Disease Notification system, we quantified the prevalence of overweight and obesity in adult US-bound refugees by nationality from 2009 through 2017. This repeated cross-sectional analysis used CDC data to quantify and examine body mass index (BMI) trends in US-bound adult refugees during 2009-2017. Utilizing data from an overseas medical exam required for all US-bound refugees, we determined BMI for 334,746 refugees >/= 18 years old who arrived in the United States during January 1, 2009-December 31, 2017. We calculated and compared the prevalence of overweight and obesity as well as changes in demographic characteristics (age, sex, and nationality) by year. Adjusted prevalence and prevalence ratios (APR) for yearly trends were assessed using a modified Poisson regression model with robust error variances. After adjusting for age, sex, and nationality, we observed a significant linear trend in the prevalence of overweight/obesity with an average annual relative percent increase of 3% for refugees entering the United States from 2009 through 2017 (APR = 1.031; 95% CI 1.029-1.033). The adjusted prevalence of overweight/obesity increased from 35.7% in 2009 to 44.7% in 2017. The prevalence of overweight and obesity in US-bound refugees increased steadily over the analysis period. Investigation into pre-migration and post-resettlement interventions is warranted.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis worldwide yet there is limited information on homotypic or heterotypic protection following natural infection to guide vaccine development. METHODS: A total of 6,020 stools collected from 299 Peruvian children between 2010 and 2014 were tested by norovirus real-time RT-PCR followed by sequence-based genotyping. Cox proportional hazards models were used to derive adjusted hazard ratios (HR) of infection among children with versus without prior exposure. RESULTS: Norovirus was detected in 1,288 (21.3%) samples. GII.4 (26%), GII.6 (19%), and GI.3 (9%) viruses accounted for 54% of infections. Homotypic protection for GI.3 (HR=0.35; p=0.015), GI.7 (HR=0.19; p=0.022), GII.4 (HR=0.39; p<0.001), and GII.6 (HR=0.52; p=0.006) infections was observed. Hazard analysis showed that children with prior GII.4 infection exhibited heterotypic protection with a 48% reduction of subsequent GI.3 infection (HR=0.52; p=0.005). Prior exposure to GI.3, GII.2, and GII.17 infections enhanced susceptibility to subsequent infections with several other norovirus genotypes. CONCLUSIONS: Children up to 2 years of age infected with GII.4 noroviruses demonstrated both homotypic and heterotypic protection to re-infection with other genotypes. These data support the need for ongoing vaccine development efforts with GII.4 as the main component and caution the inclusion of genotypes that may enhance susceptibility to infections.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis worldwide yet there is limited information on homotypic or heterotypic protection following natural infection to guide vaccine development. METHODS: A total of 6,020 stools collected from 299 Peruvian children between 2010 and 2014 were tested by norovirus real-time RT-PCR followed by sequence-based genotyping. Cox proportional hazards models were used to derive adjusted hazard ratios (HR) of infection among children with versus without prior exposure. RESULTS: Norovirus was detected in 1,288 (21.3%) samples. GII.4 (26%), GII.6 (19%), and GI.3 (9%) viruses accounted for 54% of infections. Homotypic protection for GI.3 (HR=0.35; p=0.015), GI.7 (HR=0.19; p=0.022), GII.4 (HR=0.39; p<0.001), and GII.6 (HR=0.52; p=0.006) infections was observed. Hazard analysis showed that children with prior GII.4 infection exhibited heterotypic protection with a 48% reduction of subsequent GI.3 infection (HR=0.52; p=0.005). Prior exposure to GI.3, GII.2, and GII.17 infections enhanced susceptibility to subsequent infections with several other norovirus genotypes. CONCLUSIONS: Children up to 2 years of age infected with GII.4 noroviruses demonstrated both homotypic and heterotypic protection to re-infection with other genotypes. These data support the need for ongoing vaccine development efforts with GII.4 as the main component and caution the inclusion of genotypes that may enhance susceptibility to infections.