Influenza poses a continuing public health threat in epidemic and pandemic seasons. The 1951 influenza epidemic (A/H1N1) caused an unusually high death toll in England; in particular, weekly deaths in Liverpool even surpassed those of the 1918 pandemic. We further quantified the death rate of the 1951 epidemic in 3 countries. In England and Canada, we found that excess death rates from pneumonia and influenza and all causes were substantially higher for the 1951 epidemic than for the 1957 and 1968 pandemics (by > or =50%). The age-specific pattern of deaths in 1951 was consistent with that of other interpandemic seasons; no age shift to younger age groups, reminiscent of pandemics, occurred in the death rate. In contrast to England and Canada, the 1951 epidemic was not particularly severe in the United States. Why this epidemic was so severe in some areas but not others remains unknown and highlights major gaps in our understanding of interpandemic influenza.
Swine flu (H1N1) reached pandemic proportions in 2009, yet ambivalence was met concerning intentions to be vaccinated. The present investigation determined predictors of perceived H1N1 contraction risk and vaccination intentions among Canadian adults (N = 1,027) responding to an online questionnaire. The relatively low rate of vaccination intent (30.12%, and 34.99% being unsure of their intent) was related to a sense of invulnerability regarding illness contraction and symptom severity. Most individuals were skeptical that H1N1 would be widespread, believing that less than 10% of the population would contract H1N1. Yet, they also indicated that their attitudes would change once a single person they knew contracted the illness. Also, worry regarding H1N1 was related to self-contraction risk and odds of individuals seeking vaccination. Moreover, vaccination intent was related to the perception that the threat was not particularly great, mistrust of the media to provide accurate information regarding H1N1, and whether individuals endorsed problem-focused versus avoidant coping strategies. Given the role media plays in public perceptions related to a health crisis, trust in this outlet and credibility regarding the threat are necessary for adherence to recommended measures to minimize health risk.
To retrospectively examine the barriers faced and opportunities for improvement during the 2009 H1N1 pandemic response experienced by participants responsible for the delivery of health care services in 3 remote and isolated Subarctic First Nation communities of northern Ontario, Canada.
A qualitative community-based participatory approach.
Semi-directed interviews were conducted with adult key informants (n=13) using purposive sampling of participants representing the 3 main sectors responsible for health care services (i.e., federal health centres, provincial hospitals and Band Councils). Data were manually transcribed and coded using deductive and inductive thematic analysis.
Primary barriers reported were issues with overcrowding in houses, insufficient human resources and inadequate community awareness. Main areas for improvement included increasing human resources (i.e., nurses and trained health care professionals), funding for supplies and general community awareness regarding disease processes and prevention.
Government bodies should consider focusing efforts to provide more support in terms of human resources, monies and education. In addition, various government organizations should collaborate to improve housing conditions and timely access to resources. These recommendations should be addressed in future pandemic plans, so that remote western James Bay First Nation communities of Subarctic Ontario and other similar communities can be better prepared for the next public health emergency.
Alaska Native people have suffered disproportionately from previous influenza pandemics. We evaluated 3 separate syndromic data sources to determine temporal and geographic patterns of spread of 2009 pandemic influenza A H1N1 (pH1N1) in Alaska, and reviewed records from persons hospitalized with pH1N1 disease in 3 areas in Alaska to characterize clinical and epidemiologic features of disease in Alaskans. A wave of pH1N1 disease swept through Alaska beginning in most areas in August or early September. In rural regions, where Alaska Native people comprise a substantial proportion of the population, disease occurred earlier than in other regions. Alaska Native people and Asian/Pacific Islanders (A/PI) were 2-4 times more likely to be hospitalized than whites. Alaska Native people and other minorities remain at high risk for early and substantial morbidity from pandemic influenza episodes. These findings should be integrated into plans for distribution and use of vaccine and antiviral agents.
In a pandemic situation, resources in intensive care units may be stretched to the breaking point, and critical care triage may become necessary. In such a situation, I argue that a patient's combined vulnerability to illness and social disadvantage should be a justification for giving that patient some priority for critical care. In this article I present an example of a critical care triage protocol that recognizes the moral relevance of vulnerability to illness and social disadvantage, from the Canadian province of Newfoundland and Labrador.
Timely diagnosis of influenza can help clinical management.
To examine the accuracy of rapid influenza diagnostic tests (RIDTs) in adults and children with influenza-like illness and evaluate factors associated with higher accuracy.
PubMed and EMBASE through December 2011; BIOSIS and Web of Science through March 2010; and citations of articles, guidelines, reviews, and manufacturers.
Studies that compared RIDTs with a reference standard of either reverse transcriptase polymerase chain reaction (first choice) or viral culture.
Reviewers abstracted study data by using a standardized form and assessed quality by using Quality Assessment of Diagnostic Accuracy Studies criteria.
159 studies evaluated 26 RIDTs, and 35% were conducted during the H1N1 pandemic. Failure to report whether results were assessed in a blinded manner and the basis for patient recruitment were important quality concerns. The pooled sensitivity and specificity were 62.3% (95% CI, 57.9% to 66.6%) and 98.2% (CI, 97.5% to 98.7%), respectively. The positive and negative likelihood ratios were 34.5 (CI, 23.8 to 45.2) and 0.38 (CI, 0.34 to 0.43), respectively. Sensitivity estimates were highly heterogeneous, which was partially explained by lower sensitivity in adults (53.9% [CI, 47.9% to 59.8%]) than in children (66.6% [CI, 61.6% to 71.7%]) and a higher sensitivity for influenza A (64.6% [CI, 59.0% to 70.1%) than for influenza B (52.2% [CI, 45.0% to 59.3%).
Incomplete reporting limited the ability to assess the effect of important factors, such as specimen type and duration of influenza symptoms, on diagnostic accuracy.
Influenza can be ruled in but not ruled out through the use of RIDTs. Sensitivity varies across populations, but it is higher in children than in adults and for influenza A than for influenza B.
Canada's pandemic H1N1 influenza A (pH1N1) outbreak led to a high burden of critical illness. Our objective was to describe the incidence of AKI (acute kidney injury) in these patients and risk factors for AKI, renal replacement therapy (RRT), and mortality.
From a prospective cohort of critically ill adults with confirmed or probable pH1N1 (16 April 2009-12 April 2010), we abstracted data on demographics, co-morbidities, acute physiology, AKI (defined by RIFLE criteria for Injury or Failure), treatments in the intensive care unit, and clinical outcomes. Univariable and multivariable logistic regression analyses were used to evaluate the associations between clinical characteristics and the outcomes of AKI, RRT, and hospital mortality.
We included 562 patients with pH1N1-related critical illness (479 [85.2%] confirmed, 83 [14.8%] probable]: mean age 48.0 years, 53.4% female, and 13.3% aboriginal. Common co-morbidities included obesity, diabetes, and chronic obstructive pulmonary disease. AKI occurred in 60.9%, with RIFLE categories of Injury (23.0%) and Failure (37.9%). Independent predictors of AKI included obesity (OR 2.94; 95%CI, 1.75-4.91), chronic kidney disease (OR 4.50; 95%CI, 1.46-13.82), APACHE II score (OR per 1-unit increase 1.06; 95%CI, 1.03-1.09), and P(a)O2/F(i)O2 ratio (OR per 10-unit increase 0.98; 95%CI, 0.95-1.00). Of patients with AKI, 24.9% (85/342) received RRT and 25.8% (85/329) died. Independent predictors of RRT were obesity (OR 2.25; 95% CI, 1.14-4.44), day 1 mechanical ventilation (OR 4.09; 95% CI, 1.21-13.84), APACHE II score (OR per 1-unit increase 1.07; 95% CI, 1.03-1.12), and day 1 creatinine (OR per 10 µmol/L increase, 1.06; 95%CI, 1.03-1.10). Development of AKI was not independently associated with hospital mortality.
The incidence of AKI and RRT utilization were high among Canadian patients with critical illness due to pH1N1.
Cites: Crit Care. 2004 Aug;8(4):R204-1215312219
Cites: Crit Care Med. 1985 Oct;13(10):818-293928249
2009 pandemic influenza A(H1N1) has led to a global increase in severe respiratory illness. Little is known about kidney outcomes and dialytic requirements in critically ill patients infected with pandemic H1N1.
Prospective observational study.
50 patients with pandemic H1N1 admitted to any of 7 intensive care units in Manitoba, Canada, were prospectively followed.
Outcomes were kidney injury and kidney failure defined using RIFLE (risk, injury, failure, loss, end-stage disease) criteria or need for dialysis therapy.
The pandemic H1N1 group was composed of 50 critically ill patients with pandemic H1N1 with severe respiratory syndrome (47 confirmed cases, 3 probable). Kidney injury, kidney failure, and need for dialysis occurred in 66.7%, 66%, and 11% of patients, respectively. Mortality was 16%. Kidney failure was associated with increased death (OR, 11.29; 95% CI, 1.29-98.9), whereas the need for dialysis was associated with an increase in length of stay (RR, 2.38; 95% CI, 2.13-25.75).
Small population studied from single Canadian province; thus, limited generalizability.
In critically ill patients with pandemic H1N1, kidney injury, kidney failure, and the need for dialysis are common and associated with an increase in mortality and length of intensive care unit stay.