Morbidity and Mortality Characteristics of Asian Strain Influenza

Chin, Tom D. Y.; Foley, John F.; Doto, Irene L.; Gravelle, Clifton R.; Weston, Jean K.

doi:10.2307/4590751

Cited by 49 publications

(33 citation statements)

References 8 publications

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“…Our estimates of transmissibility in households, which are lower than estimates from previous pandemics 12-14 and show a strong association with age, are consistent with and complement findings from analyses of transmissibility in the early phase of the epidemic in Mexico, which were based on aggregate population data. 20 …”

Section: Discussionsupporting

confidence: 85%

“…Previous studies showed that infectivity was greater among children than among adults during seasonal influenza outbreaks 8-11 and during the 1957 pandemic, 12-14 but the difference was not as pronounced during the 1968 pandemic. 13 However, our analysis did not provide evidence that infectivity was associated with the age of the patient, although the index patients in our analysis may not represent an unbiased sample of all community patients.…”

Section: Discussionmentioning

confidence: 86%

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Household Transmission of 2009 Pandemic Influenza A (H1N1) Virus in the United States

Cauchemez

Donnelly

Reed³

et al. 2009

N Engl J Med

436

428

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BACKGROUND As of June 11, 2009, a total of 17,855 probable or confirmed cases of 2009 pandemic influenza A (H1N1) had been reported in the United States. Risk factors for transmission remain largely uncharacterized. We characterize the risk factors and describe the transmission of the virus within households. METHODS Probable and confirmed cases of infection with the 2009 H1N1 virus in the United States were reported to the Centers for Disease Control and Prevention with the use of a standardized case form. We investigated transmission of infection in 216 households — including 216 index patients and their 600 household contacts — in which the index patient was the first case patient and complete information on symptoms and age was available for all household members. RESULTS An acute respiratory illness developed in 78 of 600 household contacts (13%). In 156 households (72% of the 216 households), an acute respiratory illness developed in none of the household contacts; in 46 households (21%), illness developed in one contact; and in 14 households (6%), illness developed in more than one contact. The proportion of household contacts in whom acute respiratory illness developed decreased with the size of the household, from 28% in two-member households to 9% in six-member households. Household contacts 18 years of age or younger were twice as susceptible as those 19 to 50 years of age (relative susceptibility, 1.96; Bayesian 95% credible interval, 1.05 to 3.78; P = 0.005), and household contacts older than 50 years of age were less susceptible than those who were 19 to 50 years of age (relative susceptibility, 0.17; 95% credible interval, 0.02 to 0.92; P = 0.03). Infectivity did not vary with age. The mean time between the onset of symptoms in a case patient and the onset of symptoms in the household contacts infected by that patient was 2.6 days (95% credible interval, 2.2 to 3.5). CONCLUSIONS The transmissibility of the 2009 H1N1 influenza virus in households is lower than that seen in past pandemics. Most transmissions occur soon before or after the onset of symptoms in a case patient.

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Section: Discussionsupporting

confidence: 85%

Section: Discussionmentioning

confidence: 86%

Household Transmission of 2009 Pandemic Influenza A (H1N1) Virus in the United States

Cauchemez

Donnelly

Reed³

et al. 2009

N Engl J Med

436

428

View full text Add to dashboard Cite

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“…and CAR within the range 30-60% (18)(19)(20)(21)(22)(23)(24)(25). The only striking difference concerned mortality: 1889 was comparable to 1957, 1968, and to the "pseudo-pandemics" of 1947 and 1977-1978 (26), thereby making the 1918 pandemic even more exceptional.…”

Section: Discussionmentioning

confidence: 99%

Transmissibility and geographic spread of the 1889 influenza pandemic

Valleron

Cori

Valtat

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

118

104

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Until now, mortality and spreading mechanisms of influenza pandemics have been studied only for the 1918, 1957, and 1968 pandemics; none have concerned the 19th century. Herein, we examined the 1889 "Russian" pandemic. Clinical attack rates were retrieved for 408 geographic entities in 14 European countries and in the United States. Case fatality ratios were estimated from datasets in the French, British and German armies, and morbidity and mortality records of Swiss cities. Weekly all-cause mortality was analyzed in 96 European and American cities. The pandemic spread rapidly, taking only 4 months to circumnavigate the planet, peaking in the United States 70 days after the original peak in St. Petersburg. The median and interquartile range of clinical attack rates was 60% (45-70%). The case fatality ratios ranged from 0.1% to 0.28%, which is comparable to those of 1957 and 1968, and 10-fold lower than in 1918. The median basic reproduction number (R 0 ) was 2.1, which is comparable to the values found for the other pandemics, despite the different viruses and contact networks. R 0 values varied widely from one city to another, and only a small minority of those values was within the range in which modelers' mitigation scenarios predicted effectiveness. The 1889 and 1918 R 0 correlated for the subset of cities for which both values were available. Social and geographic factors probably shape the local R 0 , and they could be identified to design optimal mitigation scenarios tailored to each city.epidemics | history | reproduction number | attack rate | epidemiology

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“…In general most studies have revealed highest attack rates in the population [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] years old, with lower rates among preschoolers and progressively lower rates beyond age 20 (7-9, 11, 13). This distribution is seen in illness surveys as well as in serologic studies.…”

Section: Discussionmentioning

confidence: 99%