Update: Influenza Activity in the United States During the 2018-19 Season and Composition of the 2019-20 Influenza Vaccine.

Influenza activity* in the United States during the 2018-19 season (September 30, 2018-May 18, 2019) was of moderate severity (1). Nationally, influenza-like illness (ILI)† activity began increasing in November, peaked during mid-February, and returned to below baseline in mid-April; the season lasted 21 weeks,§ making it the longest season in 10 years. Illness attributed to influenza A viruses predominated, with very little influenza B activity. Two waves of influenza A were notable during this extended season: influenza A(H1N1)pdm09 viruses from October 2018 to mid-February 2019 and influenza A(H3N2) viruses from February through May 2019. Compared with the 2017-18 influenza season, rates of hospitalization this season were lower for adults, but were similar for children. Although influenza activity is currently below surveillance baselines, testing for seasonal influenza viruses and monitoring for novel influenza A virus infections should continue year-round. Receiving a seasonal influenza vaccine each year remains the best way to protect against seasonal influenza and its potentially severe consequences.

Readiness for Responding to a Severe Pandemic 100 Years After 1918.

The 1918 H1N1 pandemic caused an unprecedented number of deaths worldwide. The tools to deal with the global emergency were limited; there were insufficient surveillance systems and a dearth of diagnostic, treatment, and prevention options. With continuing focus on pandemic planning, technologic advances in surveillance, vaccine capabilities, and 21st century medical care and countermeasures, we are more prepared for a severe pandemic than people were 100 years ago; however, notable gaps remain.

Annual estimates of the burden of seasonal influenza in the United States: A tool for strengthening influenza surveillance and preparedness.

BACKGROUND: Estimates of influenza disease burden are broadly useful for public health, helping national and local authorities monitor epidemiologic trends, plan and allocate resources, and promote influenza vaccination. Historically, estimates of the burden of seasonal influenza in the United States, focused mainly on influenza-related mortality and hospitalization, were generated every few years. Since the 2010-2011 influenza season, annual US influenza burden estimates have been generated and expanded to include estimates of influenza-related outpatient medical visits and symptomatic illness in the community. METHODS: We used routinely collected surveillance data, outbreak field investigations, and proportions of people seeking health care from survey results to estimate the number of illnesses, medical visits, hospitalizations, and deaths due to influenza during six influenza seasons (2010-2011 through 2015-2016). RESULTS: We estimate that the number of influenza-related illnesses that have occurred during influenza season has ranged from 9.2 million to 35.6 million, including 140 000 to 710 000 influenza-related hospitalizations. DISCUSSION: These annual efforts have strengthened public health communications products and supported timely assessment of the impact of vaccination through estimates of illness and hospitalizations averted. Additionally, annual estimates of influenza burden have highlighted areas where disease surveillance needs improvement to better support public health decision making for seasonal influenza epidemics as well as future pandemics.

Systematic Assessment of Multiple Routine and Near Real-Time Indicators to Classify the Severity of Influenza Seasons and Pandemics in the United States, 2003-2004 Through 2015-2016.

Assessments of influenza season severity can guide public health action. We used the moving epidemic method to develop intensity thresholds (ITs) for 3 US surveillance indicators from the 2003-2004 through 2014-2015 influenza seasons (excluding the 2009 pandemic). The indicators were: 1) outpatient visits for influenza-like illness; 2) influenza-related hospitalizations; and 3) influenza- and pneumonia-related deaths. ITs were developed for the population overall and separately for children, adults, and older adults, and they were set at the upper limit of the 50% (IT50), 90% (IT90), and 98% (IT98) 1-sided confidence intervals of the geometric mean of each season's 3 highest values. Severity was classified as low if ≥2 systems peaked below IT50, moderate if ≥2 peaked between IT50 and IT90, high if ≥2 peaked between IT90 and IT98, and very high if ≥2 peaked above IT98. We pilot-tested this method with the 2015-2016 season and the 2009 pandemic. Overall, 4 seasons were classified as low severity, 7 as moderate, 2 as high, and none as very high. Among the age groups, older adults had the most seasons (n = 3) classified as high, and children were the only group to have seasons (n = 2) classified as very high. We will apply this method to classify the severity of future seasons and inform pandemic response.

Prevention of community-associated methicillin-resistant Staphylococcus aureus infection among Asian/Pacific Islanders: a qualitative assessment.

BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasingly reported over the past decade, including in Asian/Pacific Islanders (A/PIs). METHODS: We conducted ethnographic interviews in O'ahu and Kaua'i, Hawai'i, with 10 Asian/Pacific Islanders identified as having a history of CA-MRSA infections. RESULTS: Most (7/10) thought skin infections were not a new problem in Hawai'i. Most (8/9) attempted to self-treat the infection prior to seeking medical care with a range of home remedies and store- bought solutions. Most respondents did not initially comprehend the severity of their infection and only sought medical treatment after concern from family, unbearable pain, and/or other symptoms of illness. CONCLUSION: Clinicians should be aware of the reportedly frequent use of home remedies by this population, as it may potentially contribute to interactions when treatments are combined. If clinicians and public health professionals do not address perceptions and misperceptions of how MRSA is acquired, it will be very difficult to prevent infection, and may also delay individuals from seeking treatment.

Chronic disease and disasters medication demands of Hurricane Katrina evacuees.

BACKGROUND: Preparing for natural disasters has historically focused on treatment for acute injuries, environmental exposures, and infectious diseases. Many disaster survivors also have existing chronic illness, which may be worsened by post-disaster conditions. The relationship between actual medication demands and medical relief pharmaceutical supplies was assessed in a population of 18,000 evacuees relocated to San Antonio TX after Hurricane Katrina struck the Gulf Coast in August 2005. METHODS: Healthcare encounters from day 4 to day 31 after landfall were monitored using a syndromic surveillance system based on patient chief complaint. Medication-dispensing records were collected from federal disaster relief teams and local retail pharmacies serving evacuees. Medications dispensed to evacuees during this period were quantified into defined daily doses and classified as acute or chronic, based on their primary indications. RESULTS: Of 4,229 categorized healthcare encounters, 634 (15%) were for care of chronic medical conditions. Sixty-eight percent of all medications dispensed to evacuees were for treatment of chronic diseases. Cardiovascular medications (39%) were most commonly dispensed to evacuees. Thirty-eight percent of medication doses dispensed by federal relief teams were for chronic care, compared to 73% of doses dispensed by retail pharmacies. Federal disaster relief teams supplied 9% of all chronic care medicines dispensed. CONCLUSIONS: A substantial demand for drugs used to treat chronic medical conditions was identified among San Antonio evacuees, as was a reliance on retail pharmacy supplies to meet this demand. Medical relief pharmacy supplies did not consistently reflect the actual demands of evacuees.

Role of infectious diseases consultants in management of antimicrobial use in hospitals.

The Infectious Diseases Society of America Emerging Infections Network (EIN) surveyed its members to characterize antimicrobial restriction policies in their hospitals and the involvement of infectious diseases consultants in this process. Of the 502 respondents (73%), 250 (50%) indicated that their hospital pharmacies would not dispense certain antimicrobials without approval of infectious diseases consultants. Moreover, 89% agreed that infectious diseases consultants need to be directly involved in the approval process. At hospitals with control policies, commonly restricted agents included lipid formulations of amphotericin B, carbapenems, fluoroquinolones, piperacillin-tazobactam, and vancomycin. Only 46 EIN members (18%) reported remuneration of infectious diseases consultants for participation in the approval process. Pediatric infectious diseases consultants were more likely to practice in hospitals with restriction policies than were adult infectious diseases consultants (64% vs. 45%; P<.001). Similarly, teaching hospitals were more likely to have antimicrobial-control policies than were nonteaching facilities (60% vs. 17%; P<.001).