Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-30 (of 45 Records) |
Query Trace: Nolen L[original query] |
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Previous infection and effectiveness of COVID-19 vaccination in middle- and high-school students
Almendares OM , Ruffin JD , Collingwood AH , Nolen LD , Lanier WA , Dash SR , Ciesla AA , Wiegand R , Tate JE , Kirking HL . Pediatrics 2023 152 (6) BACKGROUND AND OBJECTIVES: Understanding the real-world impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mitigation measures, particularly vaccination, in children and adolescents in congregate settings remains important. We evaluated protection against SARS-CoV-2 infection using school-based testing data. METHODS: Using data from Utah middle- and high-school students participating in school-wide antigen testing in January 2022 during omicron (BA.1) variant predominance, log binomial models were fit to estimate the protection of previous SARS-CoV-2 infection and coronavirus disease 2019 vaccination against SARS-CoV-2 infection. RESULTS: Among 17 910 students, median age was 16 years (range: 12-19), 16.7% had documented previous SARS-CoV-2 infection; 55.6% received 2 vaccine doses with 211 median days since the second dose; and 8.6% of students aged 16 to 19 years received 3 vaccine doses with 21 median days since the third dose. Protection from previous infection alone was 35.9% (95% confidence interval [CI]: 12.9%-52.8%) and 23.8% (95% CI: 2.1%-40.7%) for students aged 12 to 15 and 16 to 19 years, respectively. Protection from 2-dose hybrid immunity (previous SARS-CoV-2 infection and vaccination) with <180 days since the second dose was 58.7% (95% CI: 33.2%-74.4%) for students aged 12 to 15 and 54.7% (95% CI: 31.0%-70.3%) for students aged 16 to 19 years. Protection was highest (70.0%, 95% CI: 42.3%-84.5%) among students with 3-dose hybrid immunity, although confidence intervals overlap with 2-dose vaccination. CONCLUSIONS: The estimated protection against infection was strongest for those with hybrid immunity from previous infection and recent vaccination with a third dose. |
Estimating the number of symptomatic SARS-CoV-2 infections among vaccinated individuals in the United States—January–April, 2021 (preprint)
Kugeler KJ , Williamson J , Curns AT , Healy JM , Nolen LD , Clark TA , Martin SW , Fischer M . medRxiv 2021 2021.08.03.21261442 As of March 2021, three COVID-19 vaccines have been authorized by the U.S. Food and Drug Administration (FDA) for use in the United States. Each has substantial efficacy in preventing COVID-19. However, as efficacy from trials was <100% for all three vaccines, disease in vaccinated people is expected to occur. We created a spreadsheet-based tool to estimate the number of symptomatic vaccine breakthrough infections based on published vaccine efficacy (VE) data, percent of the population that has been fully vaccinated, and average number of COVID-19 cases reported per day. We estimate that approximately 51,000 symptomatic vaccine breakthrough infections (95% CI: ∼48,000–55,000 cases) occurred in the United States during January–April 2021 among >77 million fully vaccinated people, reflecting <0.5% of COVID-19 cases that occurred during that time. With ongoing SARS-CoV-2 transmission and increasing numbers of people vaccinated in the United States, vaccine breakthrough infections will continue to accumulate before population immunity is sufficient to interrupt transmission. Understanding expectations regarding number of vaccine breakthrough infections enables accurate public health messaging to help ensure that the occurrence of such cases does not negatively affect vaccine perceptions, confidence, and uptake.Competing Interest StatementThe authors have declared no competing interest.Funding StatementNo external funding was received.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This activity was conducted consistent with applicable federal policy.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll input data are publicly available |
Investigation of SARS-CoV-2 Transmission in The Tabernacle Choir at Temple Square in the Context of Prevention Protocols, Utah, September-November 2021.
Lanier WA , Palmer DK , Willmore DK , Oakeson KF , Young EL , Nolen LD . Public Health Rep 2023 333549231152198 Group singing and playing of wind instruments increase COVID-19 transmission risk. After a pause during the initial period of the COVID-19 pandemic, The Tabernacle Choir at Temple Square organization (hereinafter, Choir) resumed musical events in September 2021 with prevention protocols, including required vaccination and pre-event rapid antigen testing. We investigated potential SARS-CoV-2 transmission at Choir events during September 21-November 7, 2021. We interviewed COVID-19-positive members (hereinafter, case-members) and identified members exposed when a case-member attended a Choir event during his or her infectious period. We compared whole genome sequencing results to assess the genetic relatedness of available SARS-CoV-2 specimens obtained from case-members. We identified 30 case-members through pre-event testing (n = 10), self-reported positive test results (n = 18), and a review of Utah's disease surveillance system (n = 2). All 30 case-members reported symptoms; 21 (70%) were women and 23 (77%) received a positive test result by nucleic acid amplification test. No hospitalizations or deaths were reported. We identified 176 test-eligible exposed members from 14 instances of case-members attending events during their infectious periods. All were tested at least once 2 to 14 days after exposure: 74 (42%) by rapid antigen test only (all negative) and 102 (58%) by nucleic acid amplification test (4 positive, 97 negative, and 1 equivocal). Among viral sequences available from 15 case-members, the smallest single-nucleotide polymorphism distance between 2 sequences was 2, and the next-smallest distance was 10. The lack of disease detected in most exposed members suggests that minimal, if any, transmission occurred at Choir events. When community COVID-19 incidence is high, prevention protocols might help limit SARS-CoV-2 transmission during group musical activities. |
Evaluating risk factors associated with COVID-19 infections among vaccinated people early in the U.S. vaccination campaign: an observational study of five states, January-March 2021.
Sadigh KS , Kugeler KJ , Bressler S , Massay SC , Schmoll E , Milroy L , Cavanaugh AM , Sierocki A , Fischer M , Nolen LD . BMC Infect Dis 2022 22 (1) 718 BACKGROUND: COVID-19 vaccines are an effective tool to prevent illness due to SARS-CoV-2 infection. However, infection after vaccination still occurs. We evaluated all infections identified among recipients of either the Pfizer-BioNTech or Moderna COVID-19 vaccine in five U.S. states during January-March 2021. METHODS: Using observational data reported to CDC, we compared the incidence of SARS-CoV-2 infection among vaccinated and unvaccinated persons, and the sex, age, and vaccine product received for individuals with vaccine breakthrough infections to those of the vaccinated population using Poisson regression models. We also compared the proportion of vaccine breakthrough cases due to a SARS-CoV-2 variant of concern to data reported to CDC's national genomic surveillance program. RESULTS: The age-adjusted incidence of reported SARS-CoV-2 infection was 97% lower among vaccinated as compared to unvaccinated persons aged ≥ 16 years (68 vs 2252 cases per 100,000 people). Vaccinated adults aged ≥ 85 years were 1.6 times (95% CI 1.3-1.9) as likely to become infected with SARS-CoV-2 than vaccinated adults aged < 65 years. Pfizer-BioNTech COVID-19 vaccine recipients were 1.4 times (95% CI 1.3-1.6) as likely to experience infection compared to Moderna COVID-19 recipients. The proportion of infections among vaccinated persons caused by SARS-CoV-2 variants of concern was similar to the proportion of circulating viruses identified as variants of concern in the five states during the same time. CONCLUSIONS: Vaccinated persons had a substantially lower incidence of SARS-CoV-2 infection compared to unvaccinated persons. Adults aged ≥ 85 years and Pfizer-BioNTech vaccine recipients had a higher risk of infection following vaccination. We provide an analytic framework for ongoing evaluation of patterns associated with SARS-CoV-2 infection among vaccinated persons using observational surveillance and immunization data. Our findings reinforce the effectiveness of COVID-19 vaccines in preventing infection in real-world settings. |
High-contact object and surface contamination in a household of persons with Monkeypox Virus Infection - Utah, June 2022
Pfeiffer JA , Collingwood A , Rider LE , Minhaj FS , Matheny AM , Kling C , McCollum AM , Nolen LD , Morgan CN . MMWR Morb Mortal Wkly Rep 2022 71 (34) 1092-1094 In May 2022, the Salt Lake County Health Department reported two real-time polymerase chain reaction (PCR)-confirmed travel-associated cases of monkeypox to the Utah Department of Health and Human Services (UDHHS). The two persons with monkeypox (patients A and B) lived together without other housemates. Both persons experienced prodromal symptoms (e.g., fatigue and body aches). Eight days after symptom onset, patient A experienced penile lesions; lesions spread to the lips, hands, legs, chest, and scalp by day 10. Patient B experienced prodromal symptoms 8 days after illness onset of patient A; patient B experienced a lesion on the foot which spread to the leg and finger by day 11. Although both patients had lesions in multiple anatomic areas, the overall number of lesions was small, and lesions varied in presentation from "pimple-like" or ulcerated, to characteristically well-circumscribed and centrally umbilicated. Both patients had mild illness. The time from symptom onset to resolution was approximately 30 days for patient A and approximately 22 days for patient B. |
Metamodeling for policy simulations with multivariate outcomes
Zhong H , Brandeau ML , Yazdi GE , Wang J , Nolen S , Hagan L , Thompson WW , Assoumou SA , Linas BP , Salomon JA . Med Decis Making 2022 42 (7) 272989x221105079 PURPOSE: Metamodels are simplified approximations of more complex models that can be used as surrogates for the original models. Challenges in using metamodels for policy analysis arise when there are multiple correlated outputs of interest. We develop a framework for metamodeling with policy simulations to accommodate multivariate outcomes. METHODS: We combine 2 algorithm adaptation methods-multitarget stacking and regression chain with maximum correlation-with different base learners including linear regression (LR), elastic net (EE) with second-order terms, Gaussian process regression (GPR), random forests (RFs), and neural networks. We optimize integrated models using variable selection and hyperparameter tuning. We compare the accuracy, efficiency, and interpretability of different approaches. As an example application, we develop metamodels to emulate a microsimulation model of testing and treatment strategies for hepatitis C in correctional settings. RESULTS: Output variables from the simulation model were correlated (average ρ = 0.58). Without multioutput algorithm adaptation methods, in-sample fit (measured by R(2)) ranged from 0.881 for LR to 0.987 for GPR. The multioutput algorithm adaptation method increased R(2) by an average 0.002 across base learners. Variable selection and hyperparameter tuning increased R(2) by 0.009. Simpler models such as LR, EE, and RF required minimal training and prediction time. LR and EE had advantages in model interpretability, and we considered methods for improving the interpretability of other models. CONCLUSIONS: In our example application, the choice of base learner had the largest impact on R(2); multioutput algorithm adaptation and variable selection and hyperparameter tuning had a modest impact. Although advantages and disadvantages of specific learning algorithms may vary across different modeling applications, our framework for metamodeling in policy analyses with multivariate outcomes has broad applicability to decision analysis in health and medicine. |
Estimating the number of symptomatic SARS-CoV-2 infections among vaccinated individuals in the United States-January-July, 2021.
Kugeler KJ , Williamson J , Curns AT , Healy JM , Nolen LD , Clark TA , Martin SW , Fischer M . PLoS One 2022 17 (3) e0264179 As of March 2021, three COVID-19 vaccines had been authorized by the U.S. Food and Drug Administration (FDA) for use in the United States. Each has substantial efficacy in preventing COVID-19. However, as efficacy from trials was <100% for all three vaccines, disease in vaccinated people is expected to occur. We created a spreadsheet-based tool to estimate the number of symptomatic COVID-19 cases among vaccinated people (vaccine breakthrough infections) based on published vaccine efficacy (VE) data, percent of the population that has been fully vaccinated, and average number of COVID-19 cases reported per day. We estimate that approximately 199,000 symptomatic vaccine breakthrough infections (95% CI: ~183,000-214,000 cases) occurred in the United States during January-July 2021 among >156 million fully vaccinated people. With high SARS-CoV-2 transmission and increasing numbers of people vaccinated in the United States, vaccine breakthrough infections will continue to accumulate. Understanding expectations regarding number of vaccine breakthrough infections enables accurate public health messaging to help ensure that the occurrence of such cases does not negatively affect vaccine perceptions, confidence, and uptake. |
Mortality among Alaska Native adults with confirmed hepatitis C virus infection compared with the general population in Alaska, 1995-2016
Bressler SS , Bruden D , Nolen LD , Bruce MG , Towshend-Bulson L , Spradling P , McMahon BJ . Can J Gastroenterol Hepatol 2022 2022 2573545 BACKGROUND: Hepatitis C virus (HCV) infection incidence rates in the United States have increased since 2010 as a byproduct of the opioid crisis despite the introduction of direct-acting antiviral agents in 2013. HCV infection is associated with higher rates of liver-related and nonhepatic causes of death. METHODS: This study compared demographic characteristics and age-adjusted death rates from 1995 to 2016 among Alaska Native (AN) adults infected with HCV (AK-HepC) to rates among the AN and non-AN adult populations living in Alaska. Liver-related disease (LRD) and other disease-specific age-adjusted death rates were compared between the populations. RESULTS: The all-cause death rate among the AK-HepC cohort was 2.2- and 3.4-fold higher than AN and non-AN adults, respectively, and remained stable over time in all populations. The LRD death rate among the AK-HepC cohort was 18- and 11-fold higher than the non-AN and AN, respectively. The liver cancer rate among the AK-HepC cohort was 26-fold higher compared to the Alaska statewide population. The AK-HepC cohort had elevated rates of death associated with nonhepatic diseases with circulatory disease having the highest rate in all populations. Among liver cancer deaths in the AK-HepC cohort, 32% had HCV listed as a contributing cause of death on the death certificate. CONCLUSIONS: Death rates in the AK-HepC cohort remained stable since 1995 and higher compared to the general population. People with HCV infection had an elevated risk for all-cause, liver-related, and nonhepatic causes of death. Hepatitis C infection may be underrepresented as a cause of mortality in the United States. |
Characteristics of Reported Deaths Among Fully Vaccinated Persons With Coronavirus Disease 2019-United States, January-April 2021.
Watkins LKF , Mitruka K , Dorough L , Bressler SS , Kugeler KJ , Sadigh KS , Birhane MG , Nolen LD , Fischer M . Clin Infect Dis 2022 75 (1) e645-e652 BACKGROUND: COVID-19 vaccines are highly efficacious, but SARS-CoV-2 infections post-vaccination occur. We characterized COVID-19 cases among fully vaccinated persons with an outcome of death. METHODS: We analyzed COVID-19 cases voluntarily reported to CDC by US health departments during January 1, 2021-April 30, 2021. We included cases among U.S. residents with a positive SARS-CoV-2 test 14 days after completion of an authorized primary vaccine series and who had a known outcome (alive or death) as of May 31, 2021. When available, specimens were sequenced for viral lineage and death certificates were reviewed for cause(s) of death. RESULTS: Of 8,084 reported COVID-19 cases among fully vaccinated persons during the surveillance period, 245 (3.0%) died. Compared with patients who remained alive, those who died were older (median age 82 years vs. 57 years, P <0.01), more likely to reside in a long-term care facility (51% vs. 18%, P <0.01), and more likely to have at least one underlying health condition associated with risk for severe disease (64% vs. 24%, P <0.01). Among 245 deaths, 191 (78%) were classified as COVID-19-related. Of 106 deaths with available death certificates, COVID-19 was listed on 81 (77%). There were no differences in the type of vaccine administered or the most common viral lineage (B.1.1.7). CONCLUSIONS: COVID-19 deaths are rare in fully vaccinated persons, occurring most commonly in those with risk factors for severe disease, including older age and underlying health conditions. All eligible persons should be fully vaccinated against COVID-19 and follow other prevention measures to mitigate exposure risk. |
Evaluating a Cluster and the Overall Trend of Invasive Haemophilus influenzae Serotype b in Alaska 2005-2019.
Nolen LD , Topaz N , Miernyk K , Bressler S , Massay SC , Geist M , Zulz T , Singleton R . Pediatr Infect Dis J 2022 41 (4) e120-e125 BACKGROUND: In 2019, 5 cases of invasive Haemophilus influenzae serotype b (Hib) occurred in the Anchorage region of Alaska over a period of 16 days. No cases had occurred in Alaska in the preceding 26 months. METHODS: Alaska Hib isolates from 2005 through 2019 were analyzed using whole-genome sequencing (WGS). Rates were compared to the CDC's Active Bacterial Core surveillance (ABCs) data. RESULTS: A total of 33 cases of invasive Hib occurred in Alaska from 2005 through 2019. Of the 5 cases associated with the cluster, 2 (40%) occurred in adults and all occurred in the Anchorage region. In contrast, only 14% (4/28) of the noncluster cases occurred in this region (P < 0.01). Two cluster cases were linked epidemiologically and the bacteria were nearly identical. The other 3 cluster cases were caused by 3 genetically distinct bacteria. When the full period was evaluated, the unadjusted rate of invasive Hib disease in Alaska was 15.5 times higher in Alaska Native (AN) people than non-AN people [1.3/100,000 vs. 0.07/100,000, 95% confidence intervals (CI): 10.2-22.5). The age-adjusted rate of invasive Hib disease in Alaska was 9.4 times higher than the ABCs rate (95% CI: 6.3-14.1). CONCLUSIONS: While clustered in time and space, the 5 cases in 2019 were not due to a single bacterial strain. AN people continue to have elevated rates of invasive Hib infection compared to both non-AN people in Alaska and the ABCs population. |
Performance characteristics of the Abbott BinaxNOW SARS-CoV-2 antigen test in comparison to real-time RT-PCR and viral culture in community testing sites during November 2020.
Almendares O , Prince-Guerra JL , Nolen LD , Gunn JKL , Dale AP , Buono SA , Deutsch-Feldman M , Suppiah S , Hao L , Zeng Y , Stevens VA , Knipe K , Pompey J , Atherstone C , Bui DP , Powell T , Tamin A , Harcourt JL , Petway M , Bohannon C , Folster JM , MacNeil A , Salerno R , Kuhnert-Tallman W , Tate JE , Thornburg N , Kirking HL , Villanueva JM , Rose DA , Neatherlin JC , Anderson M , Rota PA , Honein MA , Bower WA . J Clin Microbiol 2021 60 (1) Jcm0174221 Point-of-care antigen tests are an important tool for SARS-CoV-2 detection. Antigen tests are less sensitive than real-time reverse-transcriptase PCR (rRT-PCR). Data on the performance of the BinaxNOW antigen test compared to rRT-PCR and viral culture by symptom and known exposure status, timing during disease or exposure period and demographic variables are limited. During November 3(rd)-17(th), 2020, we collected paired upper respiratory swab specimens to test for SARS-CoV-2 by rRT-PCR and Abbott BinaxNOW (BinaxNOW) antigen test at two community testing sites in Pima County, Arizona. We administered a questionnaire to capture symptoms, known exposure status and previous SARS-CoV-2 test results. Specimens positive by either test were analyzed by viral culture. Previously we showed overall BinaxNOW sensitivity was 52.5%. Here we showed BinaxNOW sensitivity increased to 65.7% among currently symptomatic individuals reporting a known exposure. BinaxNOW sensitivity was lower among participants with a known exposure and previously symptomatic (32.4%) or never symptomatic (47.1%) within 14 days of testing. Sensitivity was 71.1% in participants within a week of symptom onset. In participants with a known exposure, sensitivity was highest 8-10 days post-exposure (75%). The positive predictive value for recovery of virus in cell culture was 56.7% for BinaxNOW-positive and 35.4% for rRT-PCR-positive specimens. Result reporting time was 2.5 hours for BinaxNOW and 26 hours for rRT-PCR. Point-of-care antigen tests have a shorter turn-around time compared to laboratory-based nucleic acid amplification tests, which allows for more rapid identification of infected individuals. Antigen test sensitivity limitations are important to consider when developing a testing program. |
Hepatitis B virus elimination status and strategies in circumpolar countries, 2020
Haering C , McMahon B , Harris A , Weis N , Lundberg Ederth J , Axelsson M , Olafsson S , Osiowy C , Tomas K , Bollerup S , Liitsola K , Archibald C , Blystad H , Bruce M , Nolen L . Int J Circumpolar Health 2021 80 (1) 1986975 Hepatitis B virus (HBV) infection remains a global health threat. The World Health Organization (WHO) established a goal to eliminate HBV infection as a public health threat by 2030, and defined targets for key interventions to achieve that goal. We evaluated HBV burden and relevant national recommendations for progress towards WHO targets in circumpolar countries. Viral hepatitis experts of circumpolar countries were surveyed regarding their country's burden of HBV, achievement of WHO targets and national public health authority recommendations for HBV prevention and control. Eight of nine circumpolar countries responded. All countries continue to see new HBV infections. Data about HBV prevalence and progress in reaching WHO 2030 elimination targets are lacking. No country was able to report data for all seven WHO target measures. All countries have recommendations targeting the prevention of mother-to-child transmission. Only the USA and Greenland recommend universal birth dose vaccination. Four countries have recommendations to screen persons at high risk for HBV. Existing recommendations largely address prevention; however, recommendations for universal birth dose vaccination have not been widely introduced. Opportunities remain for the development of trackable targets and national elimination planning to screen and treat for HBV to reduce incidence and mortality. |
Hepatitis A vaccine immunogenicity 25 years after vaccination in Alaska
Ramaswamy M , Bruden D , Nolen LD , Mosites E , Snowball M , Nelson NP , Bruce M , McMahon BJ . J Med Virol 2021 93 (6) 3991-3994 The hepatitis A vaccine is recommended for all children greater than or equal to 1 year of age, however, the duration of vaccine protection is unknown and protection through adulthood is crucial to prevent symptomatic hepatitis later in life. We report on 25 years of follow-up of a cohort of Alaska Native individuals who were vaccinated in early childhood. We assessed the duration of vaccine protection by calculating the geometric mean concentration and proportion of participants with protective levels of IgG antibody to hepatitis A virus (anti-HAV) (≥20 mIU/mL) every 2 to 3 years. We estimated the amount of time until the anti-HAV dropped below protective levels using survival analyses. At 25 years, 43 of the original 144 participants were available, mean anti-HAV levels were 91.5 mIU/mL, and 35 (81.4%) had protective levels of anti-HAV. Using data from all persons and all time points, a survival analysis estimated 78.7% of participants had protective levels of anti-HAV at 25 years. The high level of protective antibodies in this cohort indicate that supplemental doses of hepatitis A vaccine are not needed 25 years after completion of the vaccine series. |
Monitoring Incidence of COVID-19 Cases, Hospitalizations, and Deaths, by Vaccination Status - 13 U.S. Jurisdictions, April 4-July 17, 2021.
Scobie HM , Johnson AG , Suthar AB , Severson R , Alden NB , Balter S , Bertolino D , Blythe D , Brady S , Cadwell B , Cheng I , Davidson S , Delgadillo J , Devinney K , Duchin J , Duwell M , Fisher R , Fleischauer A , Grant A , Griffin J , Haddix M , Hand J , Hanson M , Hawkins E , Herlihy RK , Hicks L , Holtzman C , Hoskins M , Hyun J , Kaur R , Kay M , Kidrowski H , Kim C , Komatsu K , Kugeler K , Lewis M , Lyons BC , Lyons S , Lynfield R , McCaffrey K , McMullen C , Milroy L , Meyer S , Nolen L , Patel MR , Pogosjans S , Reese HE , Saupe A , Sell J , Sokol T , Sosin D , Stanislawski E , Stevens K , Vest H , White K , Wilson E , MacNeil A , Ritchey MD , Silk BJ . MMWR Morb Mortal Wkly Rep 2021 70 (37) 1284-1290 COVID-19 vaccine breakthrough infection surveillance helps monitor trends in disease incidence and severe outcomes in fully vaccinated persons, including the impact of the highly transmissible B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19. Reported COVID-19 cases, hospitalizations, and deaths occurring among persons aged ≥18 years during April 4-July 17, 2021, were analyzed by vaccination status across 13 U.S. jurisdictions that routinely linked case surveillance and immunization registry data. Averaged weekly, age-standardized incidence rate ratios (IRRs) for cases among persons who were not fully vaccinated compared with those among fully vaccinated persons decreased from 11.1 (95% confidence interval [CI] = 7.8-15.8) to 4.6 (95% CI = 2.5-8.5) between two periods when prevalence of the Delta variant was lower (<50% of sequenced isolates; April 4-June 19) and higher (≥50%; June 20-July 17), and IRRs for hospitalizations and deaths decreased between the same two periods, from 13.3 (95% CI = 11.3-15.6) to 10.4 (95% CI = 8.1-13.3) and from 16.6 (95% CI = 13.5-20.4) to 11.3 (95% CI = 9.1-13.9). Findings were consistent with a potential decline in vaccine protection against confirmed SARS-CoV-2 infection and continued strong protection against COVID-19-associated hospitalization and death. Getting vaccinated protects against severe illness from COVID-19, including the Delta variant, and monitoring COVID-19 incidence by vaccination status might provide early signals of changes in vaccine-related protection that can be confirmed through well-controlled vaccine effectiveness (VE) studies. |
Genomic Diversity of Haemophilus influenzae Serotype a in an Outbreak Community, Alaska 2018.
Nolen LD , DeByle C , Topaz N , Simons BC , Tiffany A , Reasonover A , Castrodale L , McLaughlin J , Klejka J , Wang X , Bruce M . J Infect Dis 2021 225 (3) 520-524 BACKGROUND: Haemophilus influenzae serotype a (Hia) can cause severe invasive disease, especially in young children. In 2018, four invasive Hia cases occurred in an Alaska community. We used whole-genome sequencing (WGS) to evaluate the relationship of the bacteria from this community and other Alaska patients with invasive Hia. METHODS: All carriage (15) and invasive (4) Hia isolates from the outbreak community, together with 15 non-outbreak Alaska invasive Hia surveillance isolates from 2018, were tested for antimicrobial susceptibility and characterized using WGS. RESULTS: Phylogenetic analysis of both invasive and carriage Hia isolates revealed two major clades that differed by an average of 300 core single nucleotide polymorphisms (SNPs). All isolates from the outbreak community were clustered in one subclade, within a larger clade containing 3 non-outbreak invasive Hia isolates. Comparative genomics did not reveal any genetic mutations that distinguished carriage from invasive isolates. Three (20%) community isolates were rifampin-resistant and had a previously unreported mutation in the rpoB gene. CONCLUSIONS: In the outbreak community, Hia isolates from carriers were indistinguishable from the invasive Hia isolates. Overall, invasive Hia isolates from Alaska in 2018 were genetically similar. The rifampin resistance mutation is concerning as rifampin is the first-line medication for Hia prophylaxis. |
Hepatitis B Virus (HBV) Genotype: A Significant Risk Factor in Determining which Patients with Chronic HBV Infection should Undergo Surveillance for Hepatocellular Carcinoma: The Hepatitis B Alaska (HEP-B-AK) Study.
McMahon BJ , Nolen S , Snowball M , Homan C , Negus S , Roik E , Spradling PR , Bruden D . Hepatology 2021 74 (6) 2965-2973 BACKGROUND AND AIMS: Information is limited regarding hepatitis B virus (HBV) genotype and the outcome of chronic HBV (CHB) infection. We examined HBV genotype on hepatocellular carcinoma (HCC) occurrence in Alaska Native (AN) persons with CHB where five HBV genotypes are found, A2, B6, C2, D and F1. APPROACH AND RESULTS: We calculated HCC incidence per 1000 person-years of follow-up to determine which groups by age, sex, and genotype met current American Association for the Study of Liver Diseases HCC surveillance criteria. We used Poisson regression to compare HCC risk by genotype, age, sex, and Alaska region. Incidence of HCC was calculated using the sex specific AASLD cutoff recommended for the Asian population of 50 years for women and 40 years for men. HCC screening was conducted semiannually using alpha-fetoprotein levels and abdominal ultrasound. Among 1185 AN persons, median follow up was 35.1 years; 667 (63%) were male. The HBV genotype distribution was: 49% D, 18% F, 13% A, 6% C, 3% B, 0.1% H, and 12% undetermined. Sixty-three cases of HCC occurred. HCC incidence for genotype F was 5.73 per 1000 person-years of follow-up, followed by 4.77 for C, 1.28 for A, 0.47 for D and 0.00 for B. The HCC risk was higher for genotypes F (Relative rate [RR] : 12.7, 95% confidence interval [CI]: 6.1-26.4) , C (RR: 10.6, 95% CI: 4.3-26.0) and A (RR: 2.9, 95% CI: 1.0-8.0) compared to genotypes B or D. Among males < 40 years of age and females < 50 years of age, genotype F had the highest incidence (4.79/1000 person-years). CONCLUSIONS: HBV genotype was strongly associated with HCC HBV genotype should be considered in risk factor stratification. |
Gastric Cancer in Alaska Native and American Indian People Living in Alaska, 1990-2017
Nolen LD , Bressler S , Vindigni SM , Miller K , Nash S . Clin Transl Gastroenterol 2021 12 (7) e00374 INTRODUCTION: Alaska Native (AN) people experience a high burden of gastric cancer compared with other US Native and non-Native populations. Previous reports have suggested that gastric cancer in AN people occurs at a younger age and is a more aggressive pathologic type. We evaluated all cases of gastric cancer in AN people from 1990 to 2017 and compared the epidemiologic and pathologic characteristics with the gastric cancers that occurred in the same time in the US white (USW) population. METHODS: Cancer data were collected by the Alaska Native Tumor Registry and National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Comparisons were performed looking at the age and sex distribution of the affected AN and USW people, as well as the cancer characteristics, including the location, stage, and pathology. RESULTS: The age distribution was significantly different between AN and USW patients (P < 0.001), with a greater proportion of AN people diagnosed younger than 40 years (11% vs 3%, P < 0.0001) and 40-59 years (37% vs 20%, P < 0.0001). In addition, a greater proportion of AN people were diagnosed with distant stage cancer (AN: 48% and USW: 35%, P < 0.0001). The age-adjusted rate of gastric cancer in the AN population was significantly higher than the USW population (20.8 vs 6.7 per 100,000 persons, P < 0.0001). Although there has been a significant decrease in the gastric cancer incidence rate in the USW population, no significant change in incidence was seen in the AN population. DISCUSSION: This study highlights the disproportionate burden of gastric cancer in the AN population. Further work is needed to address and understand this disparity. |
COVID-19 Vaccine Breakthrough Infections Reported to CDC - United States, January 1-April 30, 2021.
CDC COVID-19 Vaccine Breakthrough Case Investigations Team , Birhane Meseret , Bressler Sara , Chang Gregory , Clark Thomas , Dorough Layne , Fischer Marc , Watkins Louise Francois , Goldstein Jason M , Kugeler Kiersten , Langley Gayle , Lecy Kristin , Martin Stacey , Medalla Felicita , Mitruka Kiren , Nolen Leisha , Sadigh Katrin , Spratling Robin , Thompson Gail , Trujillo Alma . MMWR Morb Mortal Wkly Rep 2021 70 (21) 792-793 COVID-19 vaccines are a critical tool for controlling the ongoing global pandemic. The Food and Drug Administration (FDA) has issued Emergency Use Authorizations for three COVID-19 vaccines for use in the United States.* In large, randomized-controlled trials, each vaccine was found to be safe and efficacious in preventing symptomatic, laboratory-confirmed COVID-19 (1-3). Despite the high level of vaccine efficacy, a small percentage of fully vaccinated persons (i.e. received all recommended doses of an FDA-authorized COVID-19 vaccine) will develop symptomatic or asymptomatic infections with SARS-CoV-2, the virus that causes COVID-19 (2-8). |
Evaluation of Abbott BinaxNOW Rapid Antigen Test for SARS-CoV-2 Infection at Two Community-Based Testing Sites - Pima County, Arizona, November 3-17, 2020.
Prince-Guerra JL , Almendares O , Nolen LD , Gunn JKL , Dale AP , Buono SA , Deutsch-Feldman M , Suppiah S , Hao L , Zeng Y , Stevens VA , Knipe K , Pompey J , Atherstone C , Bui DP , Powell T , Tamin A , Harcourt JL , Shewmaker PL , Medrzycki M , Wong P , Jain S , Tejada-Strop A , Rogers S , Emery B , Wang H , Petway M , Bohannon C , Folster JM , MacNeil A , Salerno R , Kuhnert-Tallman W , Tate JE , Thornburg NJ , Kirking HL , Sheiban K , Kudrna J , Cullen T , Komatsu KK , Villanueva JM , Rose DA , Neatherlin JC , Anderson M , Rota PA , Honein MA , Bower WA . MMWR Morb Mortal Wkly Rep 2021 70 (3) 100-105 Rapid antigen tests, such as the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW), offer results more rapidly (approximately 15-30 minutes) and at a lower cost than do highly sensitive nucleic acid amplification tests (NAATs) (1). Rapid antigen tests have received Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in symptomatic persons (2), but data are lacking on test performance in asymptomatic persons to inform expanded screening testing to rapidly identify and isolate infected persons (3). To evaluate the performance of the BinaxNOW rapid antigen test, it was used along with real-time reverse transcription-polymerase chain reaction (RT-PCR) testing to analyze 3,419 paired specimens collected from persons aged ≥10 years at two community testing sites in Pima County, Arizona, during November 3-17, 2020. Viral culture was performed on 274 of 303 residual real-time RT-PCR specimens with positive results by either test (29 were not available for culture). Compared with real-time RT-PCR testing, the BinaxNOW antigen test had a sensitivity of 64.2% for specimens from symptomatic persons and 35.8% for specimens from asymptomatic persons, with near 100% specificity in specimens from both groups. Virus was cultured from 96 of 274 (35.0%) specimens, including 85 (57.8%) of 147 with concordant antigen and real-time RT-PCR positive results, 11 (8.9%) of 124 with false-negative antigen test results, and none of three with false-positive antigen test results. Among specimens positive for viral culture, sensitivity was 92.6% for symptomatic and 78.6% for asymptomatic individuals. When the pretest probability for receiving positive test results for SARS-CoV-2 is elevated (e.g., in symptomatic persons or in persons with a known COVID-19 exposure), a negative antigen test result should be confirmed by NAAT (1). Despite a lower sensitivity to detect infection, rapid antigen tests can be an important tool for screening because of their quick turnaround time, lower costs and resource needs, high specificity, and high positive predictive value (PPV) in settings of high pretest probability. The faster turnaround time of the antigen test can help limit transmission by more rapidly identifying infectious persons for isolation, particularly when used as a component of serial testing strategies. |
A high-risk subpopulation in the U.S. disproportionately affected by high rates of gastric cancer: The Alaska Native people
Vindigni SM , Nolen LD , Bruce MG . Clin Gastroenterol Hepatol 2020 19 (3) 620-621 With great interest, we read the article by Thrift and El-Serag1 providing an overview of the epidemiology, risk factors, prevention, and surveillance approaches to gastric cancer. The article highlights one of the most prevalent and under-recognized malignances throughout the world, and we appreciate the authors’ discussion of this topic. Although they nicely describe varying incidence rates by geography and race/ethnicity in the United States, they failed to describe the population with the highest incidence rate in the United States, Alaska Native (AN) people. |
Vaccination status of Alaska Native persons with hepatitis a virus infection - Alaska, 1996-2018
Plumb ID , Gounder PP , Nolen LD , Massay SC , Castrodale L , McLaughlin J , Snowball M , Homan C , Nelson NP , Singleton R , Bruce MG , McMahon BJ . Clin Infect Dis 2020 72 (12) 2212-2214 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. |
Impact of Social Distancing and Travel Restrictions on non-COVID-19 Respiratory Hospital Admissions in Young Children in Rural Alaska.
Nolen LD , Seeman S , Bruden D , Klejka J , Desnoyers C , Tiesinga J , Singleton R . Clin Infect Dis 2020 72 (12) 2196-2198 Hospitalizations due to non-COVID-19 respiratory illnesses decreased dramatically after social distancing was implemented in a high-risk population in rural Alaska. Our data from the past ten respiratory seasons show that this decline is unprecedented. This demonstrates the potential secondary benefits of implementing social distancing and travel restrictions on respiratory illnesses. |
Hepatitis C management at federally qualified health centers during the opioid epidemic: A cost-effectiveness study
Assoumou SA , Nolen S , Hagan L , Wang J , Eftekhari Yazdi G , Thompson WW , Mayer KH , Puro J , Zhu L , Salomon JA , Linas BP . Am J Med 2020 133 (11) e641-e658 BACKGROUND: The opioid epidemic has been associated with an increase in hepatitis C virus (HCV) infections. Federally qualified health centers (FQHCs) have a high burden of hepatitis C disease and could serve as venues to enhance testing and treatment. METHODS: We estimated clinical outcomes and the cost-effectiveness of hepatitis C testing and treatment at US FQHCs using individual-based simulation modeling. We used individual-level data from 57 FQHCs to model 9 strategies including permutations of HCV antibody testing modality, person initiating testing and testing approach. Outcomes included life expectancy, quality adjusted life years (QALY), hepatitis C cases identified, treated and cured, and incremental cost-effectiveness ratios (ICERs). RESULTS: Compared to current practice (risk-based with laboratory-based testing), routine rapid point-of-care testing initiated and performed by a counselor identified 68% more cases after (non-reflex) RNA testing in the first month of the intervention, led to a 17% reduction in cirrhosis cases, and a 22% reduction in liver deaths among those with cirrhosis over a lifetime. Routine rapid testing initiated by a counselor or a clinician provided better outcomes at either lower total cost or at lower cost per QALY gained, when compared to all other strategies. Findings were most influenced by the proportion of patients informed of their anti-HCV test results. CONCLUSIONS: Routine anti-HCV testing followed by prompt RNA testing for positives is recommended at FQHCs to identify infections. If using dedicated staff or point-of-care testing is not feasible, then measures to improve immediate patient knowledge of antibody status should be considered. |
Presence of antibodies against Haemophilus influenzae serotype a in Alaska prior to and after the emergence of invasive infections
McClure M , Miernyk K , Bruden D , Rudolph K , Hennessy TW , Bruce MG , Nolen LD . J Infect Dis 2020 223 (2) 326-332 BACKGROUND: Haemophilus influenzae bacteria can cause asymptomatic carriage and invasive disease. H. influenzae serotype a (Hia) is an emerging cause of invasive disease in Alaska, with greatest burden occurring among rural Alaska Native (AN) children. The first case of invasive Hia (iHia) in Alaska was reported in 2002; however, it is unclear how long the pathogen has been in Alaska. METHODS: We quantified IgG antibodies against Hia (anti-Hia) in 839 banked serum samples from Alaska residents, comparing antibody concentrations in samples drawn in the decades prior to (1980s and 1990s) and after (2000s) the emergence of iHia. We also assessed serum antibody concentration by age group, region of residence, and race. RESULTS: Anti-Hia was >0.1 microg/mL in 88.1% (348/395) and 91.0% (404/444) of samples from the decades prior and after the emergence of Hia, respectively (p=0.17). No significant differences in antibody levels were detected between people from rural and urban regions (1.55 microg/mL vs. 2.08 microg/mL, p=0.91 for age >/=5) or between AN and non-AN people (2.50 microg/mL vs 2.60 microg/mL, p=0.26). CONCLUSIONS: Our results are consistent with widespread Hia exposure in Alaska predating the first iHia case. No difference in Hia antibody prevalence was detected between populations with differing levels of invasive disease. |
Haemophilus influenzae serotype a (Hia) carriage in a small Alaska community after a cluster of invasive Hia disease, 2018
Nolen LD , Tiffany A , DeByle C , Bruden D , Thompson G , Reasonover A , Hurlburt D , Mosites E , Simons BC , Klejka J , Castrodale L , McLaughlin J , Bruce MG . Clin Infect Dis 2020 73 (2) e280-e286 BACKGROUND: Between May and July 2018, four invasive Haemophilus influenzae serotype a (iHia) infections occurred in a remote Alaska community. We performed a public health response to prevent further illness and understand Hia carriage in the community. METHODS: We collected oropharyngeal (OP) samples community-wide from untreated individuals to evaluate baseline carriage. Risk factor data was collected by interview. To prevent additional illness, we offered prophylactic rifampin to individuals in contact with iHia patients (contacts) and to all children aged <10 years. OP samples were collected again eight weeks post-rifampin distribution. Samples were tested using real-time PCR and culture. RESULTS: At baseline, Hia was carried by 4/27 (14.8%) contacts and 7/364 (1.9%) non-contacts (p<0.01). Contacts aged <10 years were more likely to carry Hia at any timepoint (11/18, 61%) than contacts aged >/=10 years (3/34, 8.8%) or non-contacts aged <10 years (2/139, 1.4%) and >/=10 years (6/276, 2.2%)(p<0.001 for all). Hia carriers were clustered in nine households (7% of total households). At the household level, carriage was associated with households with >/=1 contact (PR=5.6, CI:1.3-21.6), crowding (PR=7.7, CI:1.1-199.5) and >/=3 tobacco users (PR=5.0, CI:1.2-19.6). Sixty-six percent (40/61) of contacts and 90% (111/124) of non-contacts aged <10 years received rifampin. Elevated carriage prevalence persisted in contacts when retested eight weeks after rifampin distribution (contacts 6/25 (24%), non-contacts 2/114 (1.8%), p<0.001). CONCLUSIONS: Hia carriage prevalence was significantly higher among people who had contact with iHia patients than the general community. Rifampin prophylaxis did not result in a reduction of Hia carriage prevalence in this community. |
Respiratory syncytial virus and influenza hospitalizations in Alaska native adults
Nolen LD , Seeman S , Desnoyers C , DeByle C , Klejka J , Bruden D , Rudolph K , Gerber SI , Kim L , Langley G , Patel M , Englund J , Chu HY , Tiesinga J , Singleton R . J Clin Virol 2020 127 104347 BACKGROUND: Alaska Native (AN) infants from Yukon Kuskokwim Delta (YKD) have the highest U.S. infant hospitalization rate for respiratory syncytial virus (RSV). RSV can cause significant morbidity and mortality in adult populations, although the RSV burden in AN adults is unknown. Here we investigate RSV, influenza, and human metapneumovirus (hMPV) in hospitalized rural AN adults. METHODS: YKD AN adults, hospitalized with acute respiratory illness between November 2016 and October 2018 were enrolled prospectively. Nasopharyngeal (NP) swabs were tested for RSV, influenza and hMPV using polymerase chain reaction. Hospitalization rates were calculated. RESULTS: Of 251 patients who had an NP swab, RSV was detected in 8 (3.2 %), influenza in 31 (12.4 %), and hMPV in no patients. Weighted annual rates of lower respiratory tract infection (LRTI), RSV and influenza hospitalization were 192.0 (95 % CI: 176.5-208.4), 9.1 (6.0-13.3), and 42.2 (35.1-50.2) per 10,000. The most common discharge diagnosis was pneumonia (57.0 %), followed by chronic obstructive pulmonary disease (51.4 %). Ninety-eight percent (246/251) had a medical co-morbidity and 49.8 % (125/251) lived in a house with a smoker. Overall, 6.4 % (16/251) required mechanical ventilation, and 3.6 % (9/251) died during hospitalization. Only 35.7 % (66/185) of patients admitted during influenza season had received the annual influenza vaccine. DISCUSSION: We examined adult LRTI, influenza, and RSV hospitalization rates in an AN population with high infant RSV hospitalization rates. While we confirmed a high rate of hospitalization from LRTIs and influenza, we did not find a high rate due to RSV or hMPV. Improving influenza vaccination rates, and addressing co-morbidities could reduce respiratory hospitalizations. |
Combating gastric cancer in Alaska Native people: An expert and community symposium: Alaska Native Gastric Cancer Symposium
Nolen LD , Vindigni SM , Parsonnet J , Bruce MG , Martinson HA , Thomas TK , Sacco F , Nash S , Olnes MJ , Miernyk K , Bruden D , Ramaswamy M , McMahon B , Goodman KJ , Bass AJ , Hur C , Inoue M , Camargo MC , Cho SJ , Parnell K , Allen E , Woods T , Melkonian S . Gastroenterology 2019 158 (5) 1197-1201 Alaska Native (AN) people experience higher incidence of, and mortality from, gastric cancer compared to other U.S. populations(1, 2). Compared to the general U.S. population, gastric cancer in AN people occurs at a younger age, is diagnosed at later stages, is more evenly distributed between the sexes, and is more frequently signet-ring or diffuse histology(3). It is known that the prevalence of Helicobacter pylori (Hp) infection, a risk factor for gastric cancer, is high in AN people(4); however, high antimicrobial resistance combined with high reinfection rates in Alaska make treatment at the population level complex(5). In addition, health issues in AN people are uniquely challenging due to the extremely remote locations of many residents. A multiagency workgroup hosted a symposium in Anchorage that brought internationally-recognized experts and local leaders together to evaluate issues around gastric cancer in the AN population. The overall goal of this symposium was to identify the best strategies to combat gastric cancer in the AN population through prevention and early diagnosis. |
Risk for invasive streptococcal infections among adults experiencing homelessness, Anchorage, Alaska, USA, 2002-2015
Mosites E , Zulz T , Bruden D , Nolen L , Frick A , Castrodale L , McLaughlin J , Van Beneden C , Hennessy TW , Bruce MG . Emerg Infect Dis 2019 25 (10) 1911-8 The risk for invasive streptococcal infection has not been clearly quantified among persons experiencing homelessness (PEH). We compared the incidence of detected cases of invasive group A Streptococcus infection, group B Streptococcus infection, and Streptococcus pneumoniae (pneumococcal) infection among PEH with that among the general population in Anchorage, Alaska, USA, during 2002-2015. We used data from the Centers for Disease Control and Prevention's Arctic Investigations Program surveillance system, the US Census, and the Anchorage Point-in-Time count (a yearly census of PEH). We detected a disproportionately high incidence of invasive streptococcal disease in Anchorage among PEH. Compared with the general population, PEH were 53.3 times as likely to have invasive group A Streptococcus infection, 6.9 times as likely to have invasive group B Streptococcus infection, and 36.3 times as likely to have invasive pneumococcal infection. Infection control in shelters, pneumococcal vaccination, and infection monitoring could help protect the health of this vulnerable group. |
Risk-based prenatal hepatitis C testing practices and results, Alaska 2013-2016
Nolen LD , Gustin C , Seeman S , Murphy N , Truitt S , Schillie S , Bruce MG , Bruden D , Tiesinga J , McMahon B . Can J Gastroenterol Hepatol 2019 2019 8654741 Hepatitis C virus (HCV) infection in pregnant women is of concern as it presents a health threat not only to the mother, but also to her infant. A retrospective analysis was performed to evaluate HCV testing and exposure in women who delivered infants between 2013 and 2016 at a referral hospital in Alaska. Multiple risk behaviors were evaluated, including drug dependency or abuse (drug abuse), tobacco use, alcohol dependency or abuse, and late presentation to prenatal care. Of the 2856 women who delivered between 2013 and 2016, 470 (16.5%) were tested for HCV during pregnancy and 1356 (47.5%) were tested at any time prior to delivery (including pregnancy); 62 (2.2%) were positive for HCV antibodies. Of the 162 women with a documented history of drug abuse, 95 (58.6%) were tested for HCV during pregnancy and 143 (88.3%) were tested at any time prior to delivery (including pregnancy); 30 (18.5%) were positive for HCV antibodies. Forty-nine women (34%) with a documented history of drug abuse who were not previously known to be HCV positive were not tested for HCV during their pregnancy. In conclusion, approximately 2% of pregnant women in the study population were known to have been exposed to HCV by the time of their delivery. One-third of women with documented drug abuse did not have an HCV test during pregnancy, revealing gaps in HCV testing of pregnant women. Further studies are needed to understand the full costs and benefits of risk-based screening versus universal screening in this and other populations. |
Differentiating New from Newly Detected: Melioidosis in Yap, Federated States of Micronesia.
Nolen LD , Lirow E , Gee JE , Elrod MG , Kolton CB , Liu L , Bower WA , Person MK , Marfel M , Blaney DD . Am J Trop Med Hyg 2019 101 (2) 323-327 Melioidosis is a bacterial infection caused by exposure to water or soil that contains Burkholderia pseudomallei (Bp). Burkholderia pseudomallei is endemic to many tropical and subtropical areas of the world. In 2013, the first case of melioidosis was recognized in Yap, the Federated States of Micronesia. Six additional cases were identified in the subsequent 3 years. An investigation was initiated to understand the epidemiology of melioidosis in Yap. Serum from family and community members of the identified cases were tested for antibodies to Bp. Archived serum from a 2007 Zika serosurvey were also tested for antibodies to Bp. Sequencing of bacterial isolates was performed to understand bacterial phylogeny. Soil and water were tested for the presence of Bp in the environment by culture and PCR. None of the affected patients had a history of travel to melioidosis-endemic countries. Two of the 34 (5.8%) samples from the field investigation and 67 (11.7%) of the historical samples demonstrated serologic evidence of prior Bp exposure. No Bp were detected from 30 soil or water samples. Genotype analysis showed highly related Bp isolates that were unique to Yap. Melioidosis is likely to be endemic to Yap; however, it has only recently been recognized by the clinical community in country. Further investigation is needed to understand the local sites that harbor Bp and represent the highest risk to the community. |
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