Emily Mosites

Outbreak of Invasive Infections From Subtype emm26.3 Group A Streptococcus Among Homeless Adults—Anchorage, Alaska, 2016–2017

BackgroundnIn 2016, we detected an outbreak of group A Streptococcus (GAS) invasive infections among the estimated 1000 persons experiencing homelessness (PEH) in Anchorage, Alaska. We characterized the outbreak and implemented a mass antibiotic intervention at homeless service facilities.nnnMethodsnWe identified cases through the Alaska GAS laboratory-based surveillance system. We conducted emm typing, antimicrobial susceptibility testing, and whole-genome sequencing on all invasive isolates and compared medical record data of patients infected with emm26.3 and other emm types. In February 2017, we offered PEH at 6 facilities in Anchorage a single dose of 1 g of azithromycin. We collected oropharyngeal and nonintact skin swabs on a subset of participants concurrent with the intervention and 4 weeks afterward.nnnResultsnFrom July 2016 through April 2017, we detected 42 invasive emm26.3 cases in Anchorage, 35 of which were in PEH. The emm26.3 isolates differed on average by only 2 single-nucleotide polymorphisms. Compared to other emm types, infection with emm26.3 was associated with cellulitis (odds ratio [OR], 2.5; P = .04) and necrotizing fasciitis (OR, 4.4; P = .02). We dispensed antibiotics to 391 PEH. Colonization with emm26.3 decreased from 4% of 277 at baseline to 1% of 287 at follow-up (P = .05). Invasive GAS incidence decreased from 1.5 cases per 1000 PEH/week in the 6 weeks prior to the intervention to 0.2 cases per 1000 PEH/week in the 6 weeks after (P = .01).nnnConclusionsnIn an invasive GAS outbreak in PEH in Anchorage, mass antibiotic administration was temporally associated with reduced invasive disease cases and colonization prevalence.

Environmental observation, social media, and One Health action: A description of the Local Environmental Observer (LEO) Network

As a result of the close relationships between Arctic residents and the environment, climate change has a disproportionate impact on Arctic communities. Despite the need for One Health responses to climate change, environmental monitoring is difficult to conduct in Arctic regions. The Local Environmental Observer (LEO) Network is a global social media network that recruits citizen scientists to collect environmental observations on social media. We examined the processes of the LEO Network, numbers of members and observations, and three case studies that depict One Health action enabled by the system. From February 2012 to July 2017, the LEO Network gained 1870 members in 35 countries. In this time period, 670 environmental observations were posted. Examples that resulted in One Health action include those involving food sources, wild fire smoke, and thawing permafrost. The LEO network is an example of a One Health resource that stimulates action to protect the health of communities around the world.

Antimicrobial resistance among Helicobacter pylori isolates in Alaska, 2000-2016

OBJECTIVESnAlaska Natives experience a high burden of Helicobacter pylori infection and concomitant high rates of gastric cancer. Additionally, the prevalence of antimicrobial-resistant H. pylori has been shown to be high in Alaska. In this study, antimicrobial resistance over time among sentinel surveillance isolates was evaluated and risk factors for carrying antimicrobial-resistant H. pylori were assessed.nnnMETHODSnThrough Alaskas H. pylori sentinel surveillance system, antral and fundal biopsies from Alaska Native patients undergoing esophagogastroduodenoscopy for clinical indications during 2000-2016 were collected and cultured. For positive cultures, minimum inhibitory concentrations (MICs) of metronidazole, amoxicillin, clarithromycin, tetracycline and levofloxacin were determined.nnnRESULTSnA total of 800 H. pylori isolates obtained from 763 patients were tested. Resistance to metronidazole was most common (342/800; 42.8%), followed clarithromycin (238/800; 29.8%), both clarithromycin and metronidazole (128/800; 16.0%) and levofloxacin (113/800; 14.1%). Low proportions of isolates were resistant to amoxicillin and tetracycline. Levofloxacin resistance increased between 2000 and 2016 (P<0.001), but resistance to other antimicrobials did not change over time. Metronidazole and clarithromycin resistance were more common among women (P<0.001 for both), whilst levofloxacin resistance was more common among those with an urban residence (P=0.003). Metronidazole and levofloxacin resistance were more common among older patients (P<0.05).nnnCONCLUSIONnBetween 2000 and 2016, a large percentage of H. pylori isolates received by the Alaska Sentinel Surveillance System demonstrated resistance to common antimicrobials. The surveillance system provides valuable information for clinicians to make informed treatment choices for patient with H. pylori.

Hepatitis A vaccine immune response 22 years after vaccination

In the United States, the incidence of hepatitis A virus (HAV) infection has been reduced through universal childhood vaccination. However, the duration of immunogenicity for the hepatitis A vaccine is not known. We report on the 22 year follow‐up time point of a cohort of Alaska children who were randomized to three different vaccine schedules: A) 0, 1, and 2 months; B) 0, 1, and 6 months; and C) 0, 1, and 12 months. Among 46 participant available for follow‐up, 40 (87%) maintained protective levels of anti‐hepatitis A antibody. These results indicate that a supplemental booster dose is not yet necessary at or before the 22‐year time point.

Hepatitis A vaccine immune response 22 years after vaccination: Long term hepatitis A vaccine response

In the United States, the incidence of hepatitis A virus (HAV) infection has been reduced through universal childhood vaccination. However, the duration of immunogenicity for the hepatitis A vaccine is not known. We report on the 22 year follow-up time point of a cohort of Alaska children who were randomized to three different vaccine schedules: A) 0,1,2 months; B) 0,1,6 months; and C) 0,1,12 months. Among 46 participant available for follow-up, 40 (87%) maintained protective levels of anti-hepatitis A antibody. These results indicate that a supplemental booster dose is not yet necessary at or before the 22-year time point. This article is protected by copyright. All rights reserved.

Risk Factors for Group A Streptococcus Colonization During an Outbreak Among People Experiencing Homelessness in Anchorage, Alaska, 2017

We identified risk factors for any emm type group A streptococcal (GAS) colonization while investigating an invasive emm26.3 GAS outbreak among people experiencing homelessness in Alaska. Risk factors included upper extremity skin breakdown, sleeping outdoors, sharing blankets, and infrequent tooth brushing. Our results may help guide control efforts in future outbreaks.

Observed Pneumococcal Carriage Among Alaska Native Children Who Received Reduced-Dose Schedules of 13-Valent Pneumococcal Conjugate Vaccine Between 2010 and 2012

To the Editor—In 2010, the World Health Organization (WHO) and the US Advisory Committee on Immunization Practices (ACIP) recommended the use of the 13-valent pneumococcal conjugate vaccine (PCV13) for children aged 6 weeks to 71 months in schedules of 3 primary infant doses (3 + 0), 3 doses with a booster after 1 year of age (3 + 1), or 2 primary infant doses with booster (2 + 1) [1, 2]. In countries where PCV13 use has eliminated vaccine-type disease, experts question whether a 1or 2-dose PCV13 schedule is sufficient to maintain indirect protection [3]. In immunogenicity studies, 81%–100% of children demonstrated sufficient antipolysaccharide immunoglobulin after 1 infant dose [4]. However, studies of clinical outcomes have been inconclusive. In a case-control study in the United States, low numbers of cases prevented investigators from calculating relative odds of invasive disease between partial dose groups [5]. Carriage studies can provide another marker of vaccine effectiveness, although comparisons of full and reduced PCV13 schedules and carriage have not been reported. From 2008 through 2013, we conducted annual cross-sectional pneumococcal carriage surveys among Alaskan children aged <5 years [6]. In 2010, PCV13 replaced 7-valent pneumococcal conjugate vaccine (PCV7) in Alaska’s childhood immunization schedule. During this time, children who started the vaccination schedule with PCV7 completed it with PCV13. For example, infants who received 2 doses of PCV7 could receive a final primary and booster dose of PCV13, yielding a PCV13 schedule of 1 + 1. Children enrolled during this period provided the opportunity to compare carriage of the 6 additional PCV13 serotypes (ie, 1, 3, 5, 6A, 7F, or 19A) across partial PCV13 dose groups. For each study participant, we obtained a nasopharyngeal swab specimen for pneumococcal identification and serotype determination [7]. Children were included if they received their first dose of PCV before 6 months of age. Primary doses were any dose before 12 months of age; booster doses were any dose after 12 months. Children receiving only PCV7 were included in the category of “no PCV13 doses.” We compared the prevalence of carriage of the 6 additional PCV13 serotypes between dose groups using generalized estimating equations. Models were adjusted for the year of study enrollment. From 2010 to 2012, 2762 children were enrolled; 51% were colonized with pneumococcus. Receipt of any PCV13 vaccine increased from 8% to 94%, while carriage of the additional 6 PCV13 serotypes declined from 9% to 3% (Table 1). We did not detect any statistical differences in carriage of the additional PCV13 vaccine types comparing reducedor fulldose groups to children who received no PCV13. The statistical power for these comparisons ranged from 4% to 25%. Our results indicate that we had insufficient power to detect a difference between dose groups, despite a large sample size. To evaluate the effect C O R R E S P O N D E N C E

Letter: hepatocellular carcinoma risk after hepatitis B surface antigen seroclearance - authors' reply.

ance was significantly associated with a reduced risk for HCC development compared with those without HBsAg seroclearance (P < 0.001). In summary, existing lines of evidence indicate that spontaneous or post-treatment seroclearance of HBsAg, albeit rare, does occur in CHB patients. Moreover, such situation may not indicate viral clearance. HBV persisted at low replicative and transcriptional levels after HBsAg seroclearance. In order to provoke more and earlier HBsAg seroclearance in CHB patients, we need a better understanding of the mechanisms involved in HBsAg seroclearance.