Characterizing the etiology of recurrent tuberculosis using whole genome sequencing-Alaska, USA, 2008-2020.

BACKGROUND: Understanding the etiology of recurrent tuberculosis (rTB) is important for effective TB control. Prior to the advent of whole genome sequencing (WGS), attributing rTB to relapse or reinfection using genetic information was complicated by the limited resolution of conventional genotyping methods. METHODS: We applied a systematic method of evaluating whole genome single nucleotide polymorphism (wgSNP) distances and results of phylogenetic analyses to characterize the etiology of rTB in American Indian and Alaska Native (AIAN) persons in Alaska during 2008-2020. We contextualized our findings through descriptive analyses of surveillance data and results of a literature search for investigations that characterized rTB etiology using WGS. RESULTS: The percentage of TB cases in AIAN persons in Alaska classified as recurrent episodes (11.8%) was three times the national percentage (3.9%). Of 38 recurrent episodes included in genetic analyses, we attributed 25 (65.8%) to reinfection based on wgSNP distances and phylogenetic analyses; this proportion was the highest among 16 published point estimates identified through the literature search. By comparison, we attributed 11 of 38 (28.9%) and 6 of 38 (15.8%) recurrent episodes to reinfection based on wgSNP distances alone and on conventional genotyping methods, respectively. CONCLUSIONS: WGS and attribution criteria involving genetic distances and patterns of relatedness can provide an effective means of elucidating rTB etiology. Our findings indicate that rTB occurs at high proportions among AIAN persons in Alaska and is frequently attributable to reinfection, reinforcing the importance of active surveillance and control measures to limit the spread of TB disease in Alaskan AIAN communities.

Work-related injuries in the Alaska logging industry, 1991-2014.

BACKGROUND: Although loggers in Alaska are at high risk for occupational injury, no comprehensive review of such injuries has been performed since the mid-1990s. We investigated work-related injuries in the Alaska logging industry during 1991-2014. METHODS: Using data from the Alaska Trauma Registry and the Alaska Occupational Injury Surveillance System, we described fatal and nonfatal injuries by factors including worker sex and age, timing and geographic location of injuries, and four injury characteristics. Annual injury rates and associated 5-year simple moving averages were calculated. RESULTS: We identified an increase in the 5-year simple moving averages of fatal injury rates beginning around 2005. While injury characteristics were largely consistent between the first 14 and most recent 10 years of the investigation, the size of logging companies declined significantly between these periods. CONCLUSIONS: Factors associated with declines in the size of Alaska logging companies might have contributed to the observed increase in fatal injury rates.

Novel Orthopoxvirus Infection in an Alaska Resident.

BACKGROUND.: Human infection by orthopoxviruses is being reported with increasing frequency, attributed in part to the cessation of smallpox vaccination and concomitant waning of population-level immunity. In July 2015, a female resident of interior Alaska presented to an urgent care clinic with a dermal lesion consistent with poxvirus infection. Laboratory testing of a virus isolated from the lesion confirmed infection by an Orthopoxvirus. METHODS.: The virus isolate was characterized by using electron microscopy and nucleic acid sequencing. An epidemiologic investigation that included patient interviews, contact tracing, and serum testing, as well as environmental and small-mammal sampling, was conducted to identify the infection source and possible additional cases. RESULTS.: Neither signs of active infection nor evidence of recent prior infection were observed in any of the 4 patient contacts identified. The patient's infection source was not definitively identified. Potential routes of exposure included imported fomites from Azerbaijan via the patient's cohabiting partner or wild small mammals in or around the patient's residence. Phylogenetic analyses demonstrated that the virus represents a distinct and previously undescribed genetic lineage of Orthopoxvirus, which is most closely related to the Old World orthopoxviruses. CONCLUSIONS.: Investigation findings point to infection of the patient after exposure in or near Fairbanks. This conclusion raises questions about the geographic origins (Old World vs North American) of the genus Orthopoxvirus. Clinicians should remain vigilant for signs of poxvirus infection and alert public health officials when cases are suspected.

Increase in Adverse Reactions Associated with Use of Synthetic Cannabinoids - Anchorage, Alaska, 2015-2016.

In July 2015, personnel in the Alaska Division of Public Health's Section of Epidemiology became aware of an increase in the number of patients being treated in Anchorage hospital emergency departments for adverse reactions associated with use of synthetic cannabinoids (SCs). SCs are a chemically diverse class of designer drugs that bind to the same cannabinoid receptors as tetrahydrocannabinol, the main psychoactive component of cannabis. A public health investigation was initiated to describe clinical outcomes, characterize the outbreak, and identify SC chemicals circulating in Anchorage. During July 15, 2015-March 15, 2016, a total of 1,351 ambulance transports to Anchorage emergency departments for adverse SC reactions were identified. A review of charts obtained from two Anchorage hospitals determined that among 167 emergency department visits for adverse SC reactions during July 15-September 30, 2015, 11 (6.6%) involved a patient who required endotracheal intubation, 17 (10.2%) involved a patient who was admitted to the intensive care unit, and 66 (39.5%) involved a patient classified as being homeless. Testing of 25 product and paraphernalia samples collected from patients at one hospital identified 11 different SC chemicals. Educational outreach campaigns focused on the considerable health risks of using SCs need to complement judicial and law enforcement actions to reduce SC use.

Using Geographic Disaggregation to Compare Tuberculosis Epidemiology Among American Indian and Alaska Native Persons-USA, 2010-2020.

BACKGROUND: American Indian and Alaska Native (AIAN) populations are frequently associated with the highest rates of tuberculosis (TB) disease of any racial/ethnic group in the USA. We systematically investigated variation in patterns and potential drivers of TB epidemiology among geographically distinct AIAN subgroups. METHODS: Using data reported to the National Tuberculosis Surveillance System during 2010-2020, we applied a geographic method of data disaggregation to compare annual TB incidence and the frequency of TB patient characteristics among AIAN persons in Alaska with AIAN persons in other states. We used US Census data to compare the prevalence of substandard housing conditions in AIAN communities in these two geographic areas. RESULTS: The average annual age-adjusted TB incidence among AIAN persons in Alaska was 21 times higher than among AIAN persons in other states. Compared to AIAN TB patients in other states, AIAN TB patients in Alaska were associated with significantly higher frequencies of multiple epidemiologic TB risk factors (e.g., attribution of TB disease to recent transmission, previous diagnosis of TB disease) and significantly lower frequencies of multiple clinical risk factors for TB disease (e.g., diagnosis with diabetes mellitus, end-stage renal disease). Occupied housing units in AIAN communities in Alaska were associated with significantly higher frequencies of multiple measures of substandard housing conditions compared to AIAN communities in other states. CONCLUSIONS: Observed differences in patient characteristics and substandard housing conditions are consistent with contrasting syndromes of TB epidemiology in geographically distinct AIAN subgroups and suggest ways that associated public health interventions could be tailored to improve efficacy.

Impact of a Prenatal Vitamin D Supplementation Program on Vitamin D Deficiency, Rickets and Early Childhood Caries in an Alaska Native Population.

Background: Early childhood rickets increased in Alaska Native children after decreases in vitamin D-rich subsistence diet in childbearing-aged women. We evaluated the impact of routine prenatal vitamin D supplementation initiated in Alaska's Yukon Kuskokwim Delta in Fall 2016. Methods: We queried electronic health records of prenatal women with 25(OH) vitamin D testing during the period 2015−2019. We evaluated 25(OH)D concentrations, vitamin D3 supplement refills, and decayed, missing, and filled teeth (dmft) scores and rickets in offspring. Results: Mean 25(OH)D concentrations increased 36.5% from pre- to post-supplementation; the percentage with deficient 25(OH)D decreased by 66.4%. Women with ≥ 60 vitamin D3 refill days had higher late pregnancy 25(OH)D concentrations than those with no refill days (p < 0.0001). Women with late pregnancy insufficient 25(OH)D concentrations had offspring with higher dmft scores than those with sufficient 25(OH)D (RR 1.3, p < 0.0001). Three children were diagnosed with nutritional rickets during the period 2001−2021, and none after 2017. Conclusions: These findings suggest that prenatal vitamin D supplementation can improve childhood outcomes in high-risk populations with high rates of rickets.

Outbreak of campylobacteriosis associated with consumption of raw peas.

BACKGROUND: Campylobacter jejuni is a leading cause of acute gastroenteritis worldwide, and most cases are identified as sporadic events rather than as parts of recognized outbreaks. We report findings from a substantial 2008 campylobacteriosis outbreak with general implications for fresh produce safety. METHODS: We conducted a matched case-control study to determine the source of the outbreak and enhanced surveillance to identify additional cases. Clinical and environmental specimens were tested for Campylobacter, and isolates were subtyped by pulsed-field gel electrophoresis (PFGE). RESULTS: By routine surveillance, we identified 63 cases of laboratory-confirmed infection. Only raw peas, consumed by 30 (67%) of 45 case-patients and by 15 (17%) of 90 control participants, were associated with illness (adjusted odds ratio: 8.2; P<.001). An additional 69 patients (26 laboratory-confirmed) who reported eating raw peas within 10 days of illness onset were identified through enhanced surveillance. In all, 5 cases were hospitalized, and Guillain-Barré syndrome developed in 1 case; none died. The implicated pea farm was located near a Sandhill crane (Grus canadensis) stopover and breeding site. Of 36 environmental samples collected, 16 were positive for C. jejuni-14 crane-feces samples and 2 pea samples. We identified 25 unique combined SmaI-KpnI PFGE patterns among clinical isolates; 4 of these combined PFGE patterns identified in 15 of 55 human isolates were indistinguishable from PFGE patterns identified in environmental samples. CONCLUSIONS: This investigation established a rare laboratory-confirmed link between a campylobacterosis outbreak and an environmental source and identified wild birds as an underrecognized source of produce contamination.

Endemic foodborne botulism among Alaska Native persons--Alaska, 1947-2007.

BACKGROUND: Foodborne botulism resulting from consumption of uncooked aquatic game foods has been an endemic hazard among Alaska Native populations for centuries. Our review was conducted to help target botulism prevention and response activities. METHODS: Records of Alaska botulism investigations for the period 1947-2007 were reviewed. We used the Centers for Disease Control and Prevention case definitions for foodborne botulism and linear regression to evaluate incidence trends and χ(2) or Fisher's Exact tests to evaluate categorical data. RESULTS: A total of 317 patients (61% of whom were female) and 159 outbreaks were reported. Overall mean annual incidence was 6.9 cases per 100,000 Alaska Native persons; mean incidence was lower in 2000 (5.7 cases per 100,000 Alaska Native persons) than in any period since 1965-1969 (0.8 cases per 100,000 Alaska Native persons). Age-specific incidence was highest (26.6 cases per 100,000 Alaska Native persons) among persons aged ≥60 years. The overall case-fatality rate was 8.2%, and the case-fatality rate was ≤4.0% since 1980. Misdiagnosis was associated with a higher case-fatality rate and delayed antitoxin administration. CONCLUSIONS: Foodborne botulism remains a public health problem in Alaska. Incidence might be decreasing, but it remains >800 times the overall US rate (0.0068 cases per 100,000 persons). Prevention messages should highlight the additional risk to female individuals and older persons. Early diagnosis is critical for timely access to antitoxin and supportive care.

Outbreak of pneumonia associated with emergent human adenovirus serotype 14--Southeast Alaska, 2008.

BACKGROUND: In September 2008, an outbreak of pneumonia associated with an emerging human adenovirus (human adenovirus serotype 14 [HAdV-14]) occurred on a rural Southeast Alaska island. Nine patients required hospitalization, and 1 patient died. METHODS: To investigate the outbreak, pneumonia case patients were matched to control participants on the basis of age, sex, and community of residence. Participants in the investigation and their household contacts were interviewed, and serum samples and respiratory tract specimens were collected. Risk factors were evaluated by means of conditional logistic regression. RESULTS: Among 32 pneumonia case patients, 21 (65%) had confirmed or probable HAdV-14 infection. None of 32 matched control participants had evidence of HAdV-14 infection (P<.001 for the difference). Factors independently associated with pneumonia included contact with a known HAdV-14-infected case patient (odds ratio [OR], 18.3 [95% confidence interval {CI}, >or=2.0]), current smoking (OR, 6.7 [95% CI, >or=0.9]), and having neither traveled off the island nor attended a large public gathering (OR, 14.7 [95% CI, >or=2.0]). Fourteen (67%) of 21 HAdV-14-positive case patients belonged to a single network of people who socialized and often smoked together and infrequently traveled off the island. HAdV-14 infection occurred in 43% of case-patient household contacts, compared with 5% of control-participant household contacts (P = .005). CONCLUSIONS: During a community outbreak in Alaska, HAdV-14 appeared to have spread mostly among close contacts and not widely in the community. Demographic characteristics and illness patterns among the case patients were similar to those observed in other recent outbreaks of HAdV-14 infection in the United States.

Outbreak of Vibrio parahaemolyticus gastroenteritis associated with Alaskan oysters.

BACKGROUND: Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis in the United States, typically is associated with the consumption of raw oysters gathered from warm-water estuaries. We describe a recognized outbreak of V. parahaemolyticus infection associated with the consumption of seafood from Alaska. METHODS: After we received reports of the occurrence of gastroenteritis on a cruise ship, we conducted a retrospective cohort study among passengers, as well as active surveillance throughout Alaska to identify additional cases, and an environmental study to identify sources of V. parahaemolyticus and contributors to the outbreak. RESULTS: Of 189 passengers, 132 (70 percent) were interviewed; 22 of the interviewees (17 percent) met our case definition of gastroenteritis. In our multiple logistic-regression analysis, consumption of raw oysters was the only significant predictor of illness; the attack rate among people who consumed oysters was 29 percent. Active surveillance identified a total of 62 patients with gastroenteritis. V. parahaemolyticus serotype O6:K18 was isolated from the majority of patients tested and from environmental samples of oysters. Patterns on pulsed-field gel electrophoresis were highly related across clinical and oyster isolates. All oysters associated with the outbreak were harvested when mean daily water temperatures exceeded 15.0 degrees C (the theorized threshold for the risk of V. parahaemolyticus illness from the consumption of raw oysters). Since 1997, mean water temperatures in July and August at the implicated oyster farm increased 0.21 degrees C per year (P<0.001 by linear regression); 2004 was the only year during which mean daily temperatures in July and August at the shellfish farm did not drop below 15.0 degrees C. CONCLUSIONS: This investigation extends by 1000 km the northernmost documented source of oysters that caused illness due to V. parahaemolyticus. Rising temperatures of ocean water seem to have contributed to one of the largest known outbreaks of V. parahaemolyticus in the United States.

Outbreak of multidrug-resistant Salmonella typhimurium associated with ground beef served at a school potluck.

An outbreak of gastroenteritis occurred among at least 47 persons attending a school potluck. Illness was associated with consumption of ground beef (estimated odds ratio, 16.3; 95% confidence interval, 2.2 to 338.3). Salmonella Typhimurium isolated from infected individuals and the implicated ground beef revealed identical pulsed-field gel electrophoresis patterns and was multidrug resistant. The implicated ground beef was improperly handled during the cooking process and stored above the U.S. Food and Drug Administration cooling temperature standard for >15 h before being served. This outbreak demonstrates the limitations of food safety regulations in settings where foods are prepared in the home environment for communal potlucks, bake sales, or other such gatherings held at schools, churches, or other institutions. Public health authorities should encourage school and other institutional administrators to develop policies that require dissemination of safe food preparation guidelines to prospective food handlers when such events are scheduled.

Association of regulatory issues with an echovirus 18 meningitis outbreak at a children's summer camp in Alaska.

We document an echovirus 18 meningitis outbreak occurring at a remote overnight children's camp in Alaska. The outbreak involved 26% of 113 camp residents, was associated with building overcrowding and occurred in a camp with a contaminated drinking water source. Lack of specific children's camp regulations and failure to implement and enforce existing regulations may have contributed to the outbreak.

Persistence of botulinum toxin in patients' serum: Alaska, 1959-2007.

Persistence of circulating toxin in patients with foodborne botulism is not well characterized. Recommendations for administration of botulinum antitoxin are ambiguous for patients with late-presenting disease, such as a Florida woman with toxin-positive serum 12 days after toxin ingestion. We reviewed Alaska records of foodborne outbreaks of botulism that occurred during 1959-2007 to examine the period after ingestion during which toxin was detected. Of 64 cases with toxin-positive serum, toxin was detected up to 11 days after ingestion. The findings from Alaska and Florida support administration of antitoxin up to 12 days after toxin ingestion but do not indicate when circulating toxin should no longer be present.

Increasing insect reactions in Alaska: is this related to changing climate?

In 2006, Fairbanks, AK, reported its first cases of fatal anaphylaxis as a result of Hymenoptera stings concurrent with an increase in insect reactions observed throughout the state. This study was designed to determine whether Alaska medical visits for insect reactions have increased. We conducted a retrospective review of three independent patient databases in Alaska to identify trends of patients seeking medical care for adverse reactions after insect-related events. For each database, an insect reaction was defined as a claim for the International Classification of Diseases, Ninth Edition (ICD-9), codes E9053, E906.4, and 989.5. Increases in insect reactions in each region were compared with temperature changes in the same region. Each database revealed a statistically significant trend in patients seeking care for insect reactions. Fairbanks Memorial Hospital Emergency Department reported a fourfold increase in patients in 2006 compared with previous years (1992-2005). The Allergy, Asthma, and Immunology Center of Alaska reported a threefold increase in patients from 1999 to 2002 to 2003 to 2007. A retrospective review of the Alaska Medicaid database from 1999 to 2006 showed increases in medical claims for insect reactions among all regions, with the largest percentage of increases occurring in the most northern areas. Increases in insect reactions in Alaska have occurred after increases in annual and winter temperatures, and these findings may be causally related.

Gastroenteritis outbreak among mountaineers climbing the West Buttress route of Denali - Denali National Park, Alaska, June 2002.

OBJECTIVE: To determine the burden of and risk factors for diarrheal illness among mountaineers climbing Denali during the spring of 2002. METHODS: We conducted a retrospective cohort study of all willing and available climbers who returned to base camp from June 11 to 14, 2002. We used a questionnaire that addressed illness status, demographics, and potential risk factors for illness. A case of diarrhea was defined as self-reported diarrhea (loose stool) in a Denali climber who did not have diarrhea before arrival at base camp. RESULTS: Thirty-eight (29%) of the 132 climbers who were interviewed reported experiencing diarrhea at some point on the mountain. Spending 8 or more days at the 17 200-foot high camp; being a member of a climbing party in which at least 1 other person also had diarrhea, especially if tent occupancy was 3 or more; and not receiving education about disease risk-reduction techniques among climbers who were on a guided expedition were associated with increased risk of illness. CONCLUSIONS: To prevent infectious diarrheal outbreaks among mountaineers climbing Denali (and other highly trafficked alpine routes), we recommend that park staff provide climbers with detailed information related to minimizing disease risk and develop more effective strategies for preventing climbers from depositing fecal material directly into snow along the route, such as establishing and enforcing firmer penalties for noncompliance with existing human waste disposal regulations and requiring the use of personal stool-hauling devices.

Botulism type E outbreak associated with eating a beached whale, Alaska.

We report an outbreak of botulism that occurred in July 2002 in a group of 12 Alaskan Yu'pik Eskimos who ate blubber and skin from a beached beluga whale. Botulism death rates among Alaska Natives have declined in the last 20 years, yet incidence has increased.