Nirsevimab Effectiveness Against Medically Attended Respiratory Syncytial Virus Illness and Hospitalization Among Alaska Native Children - Yukon-Kuskokwim Delta Region, Alaska, October 2023-June 2024.

Respiratory syncytial virus (RSV) is a leading cause of hospitalization among young children. Historically, American Indian and Alaska Native (AI/AN) children have experienced high rates of RSV-associated hospitalization. In August 2023, a preventive monoclonal antibody (nirsevimab) was recommended for all infants aged <8 months (born during or entering their first RSV season) and for children aged 8-19 months (entering their second RSV season) who have increased risk for severe RSV illness, including all AI/AN children.

Factors Associated With Hepatitis A Seropositivity at 23 Years After Childhood Vaccination.

We evaluated factors associated with the presence of hepatitis A virus antibodies 23 years after initiating vaccination at ages 6-15 months. Among 67 participants, 86% (42/49) of those vaccinated at ages 12-15 months and 61% (11/18) of those vaccinated at 6 months remained seropositive at 23 years. Lack of maternal antibodies at enrollment and higher initial vaccine response were independently associated with higher antibody concentrations at 23 years.

Immunogenicity of quadrivalent human papillomavirus vaccine among Alaska Native children aged 9-14 years at 5 years after vaccination.

Background: Persistent human papillomavirus (HPV) infection can cause anogenital and oropharyngeal cancers. Many HPV infections and HPV-associated cancers are vaccine-preventable. Studies suggest long-term persistence of vaccine-induced antibodies.

Trends in Otitis Media Ambulatory Visits in American Indian and Alaska Native Children During the Pneumococcal Conjugate Vaccine Period and the COVID-19 Pandemic.

Otitis media-associated outpatient visits among American Indians/Alaska Natives children <5 years old decreased by 52% (100 to 48 per 100 children per year) from 2003 to 2019. Otitis media visits decreased by another 50% from 2019 to 2020, but rebounded between 2020 and 2021 back to a rate similar to 2019.

Rate and durability of the clearance of HBsAg in Alaska Native persons with long-term HBV infection: 1982-2019.

Background And Aims: A functional cure and therapeutic end point of chronic HBV infection is defined as the clearance of HBsAg from serum. Little is known about the long-term durability of HBsAg loss in the Alaskan Native population.

Approach And Results: We performed a retrospective cohort study of Alaska Native patients with chronic HBV-monoinfection from January 1982 through December 2019.

Invasive Pneumococcal Disease and Potential Impact of Pneumococcal Conjugate Vaccines Among Adults, Including Persons Experiencing Homelessness-Alaska, 2011-2020.

Background: Adults aged ≥65 years, adults with certain underlying medical conditions, and persons experiencing homelessness are at increased risk for invasive pneumococcal disease (IPD). Two new pneumococcal conjugate vaccines, 15-valent pneumococcal conjugate vaccine (PCV15) and 20-valent pneumococcal conjugate vaccine (PCV20), were recently approved for use in US adults. We describe the epidemiology of IPD among Alaska adults and estimate the proportion of IPD cases potentially preventable by new vaccines.

Risk factors for Ebola virus disease among household care providers, Sierra Leone, 2015.

Background: Household contacts who provide care to an Ebola virus disease (EVD) case have a 3-fold higher risk of EVD compared with contacts who do not provide care.

Methods: We enrolled persons with confirmed EVD from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index cases and contacts were interviewed, and contacts were followed for 21 days to identify secondary cases.

Protection and antibody levels 35 years after primary series with hepatitis B vaccine and response to a booster dose.

Background And Aims: The duration of protection from hepatitis B vaccination in children and adults is not known. In 1981, we used three doses of plasma-derived hepatitis B vaccine to immunize a cohort of 1578 Alaska Native adults and children from 15 Alaska communities who were ≥6 months old.

Approach And Results: We tested persons for antibody to hepatitis B surface antigen (anti-HBs) levels 35 years after receiving the primary series.

Antigen Test Positivity After COVID-19 Isolation - Yukon-Kuskokwim Delta Region, Alaska, January-February 2022.

Isolation is recommended during acute infection with SARS-CoV-2, the virus that causes COVID-19, but the duration of infectiousness varies among individual persons. Rapid antigen test results have been correlated with detection of viable virus (1-3) and might inform isolation guidance, but data are limited for the recently emerged SARS-CoV-2 B.1.

Mortality among Alaska Native Adults with Confirmed Hepatitis C Virus Infection Compared with the General Population in Alaska, 1995-2016.

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.

The Alaska Native/American Indian experience of hepatitis C treatment with sofosbuvir-based direct-acting antivirals.

Background: Direct-acting antiviral (DAA) drugs have been effective in the treatment of chronic hepatitis C virus (HCV) infection. Limited data are available on safety, tolerability, and efficacy in American Indian or Alaska Native people. We aim to evaluate the treatment outcomes of sofosbuvir- based regimens for treatment of HCV in a real life setting in Alaska Native/American Indian (AN/AI) people.

Use of Rapid Antigen Testing for SARS-CoV-2 in Remote Communities - Yukon-Kuskokwim Delta Region, Alaska, September 15, 2020-March 1, 2021.

Controlling the spread of SARS-CoV-2, the virus that causes COVID-19, in Alaska is challenging. Alaska includes many remote and isolated villages with small populations (ranging from 15 to >1,000 persons) that are accessible only by air from larger communities. Until rapid point-of-care testing became widely available, a primary challenge in the diagnosis of COVID-19 in rural Alaska was slow turnaround times for SARS-CoV-2 test results, attributable to the need to transport specimens to testing facilities.

HBV Genotype: A Significant Risk Factor in Determining Which Patients With Chronic HBV Infection Should Undergo Surveillance for HCC: The Hepatitis B Alaska Study.

Background And Aims: Information is limited regarding HBV genotype and the outcome of chronic HBV (CHB) infection. We examined the effect of HBV genotype on 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 1,000 person-years of follow-up to determine which groups by age, sex, and genotype met current American Association for the Study of Liver Diseases (AASLD) HCC surveillance criteria.

Using electronic dental records to establish a surveillance system for dental decay in rural Western Alaska.

Objectives: Previous surveys have demonstrated high rates of early childhood caries (ECC) in the Alaska Native (AN) population of western Alaska. There are many challenges to providing dental care in this road-less Yukon-Kuskokwim Delta region. The regional Tribal Health Organization implemented an electronic dental record (EDR) system in the late 1990s.

Impact of Social Distancing and Travel Restrictions on Non-Coronavirus Disease 2019 (Non-COVID-19) Respiratory Hospital Admissions in Young Children in Rural Alaska.

Hospitalizations due to non-coronavirus disease 2019 (non-COVID-19) respiratory illnesses decreased dramatically after social distancing was implemented in a high-risk population in rural Alaska; an unprecedented decline compared to the past 10 respiratory seasons. This demonstrates the potential secondary benefits of implementing social distancing and travel restrictions on respiratory illnesses.

Presence of Antibodies Against Haemophilus influenzae Serotype a in Alaska Before and After the Emergence of Invasive Infections.

Background: Haemophilus influenzae bacteria can cause asymptomatic carriage and invasive disease. Haemophilus 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.

Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: A systematic review of prevalence and individual participant data meta-analysis of risk factors.

Background: Colonisation with Streptococcus pneumoniae can lead to invasive pneumococcal disease and pneumonia. Pneumococcal acquisition and prevalence of colonisation are high in children. In older adults, a population susceptible to pneumococcal disease, colonisation prevalence is reported to be lower, but studies are heterogeneous.

Haemophilus influenzae Serotype a (Hia) Carriage in a Small Alaska Community After a Cluster of Invasive Hia Disease, 2018.

Background: Between May and July 2018, 4 Haemophilus influenzae serotype a (Hia) infections occurred in a remote Alaska community. We performed a public health response to prevent further illness and understand Hia carriage.

Methods: We collected oropharyngeal samples community-wide to evaluate baseline carriage.

Increasing non-susceptibility to antibiotics within carried pneumococcal serotypes - Alaska, 2008-2015.

Background: In Alaska, while introduction of 13-valent pneumococcal conjugate vaccine led to declines in invasive pneumococcal disease, carriage prevalence remained stable because of replacement with non-vaccine serotypes. We assessed antibiotic non-susceptibility of carried pneumococci during serotype redistribution, determined the contributions of within-serotype shifts, and assessed factors that could explain changes in non-susceptibility.

Methods: Each year from 2008 to 2015, at multiple sites in Alaska, we collected nasopharyngeal swabs and completed surveys for a convenience sample of participants.

Respiratory syncytial virus and influenza hospitalizations in Alaska native adults.

Background: Alaska Native (AN) infants from Yukon Kuskokwim Delta (YKD) have the highest U.S. infant hospitalization rate for respiratory syncytial virus (RSV).

Presence of genes and characterization of s, i and m regions in isolated from Alaskans and their association with clinical pathologies.

Gastric cancer is a health disparity in the Alaska Native people. The incidence of infection, a risk factor for non-cardia gastric adenocarcinoma, is also high. Gastric cancer is partially associated with the virulence of the infecting strain.