- ProMed Mail Source: The Wall Street Journal Health (edited)
- Swine Flu Deaths Higher In Elderly
- By Jennifer Corbett Dooren
- People age 50 and older who were hospitalized with swine
flu [influenza pandemic (H1N1) 2009 virus infection] in California had
the highest fatality rate from the illness, while those younger than 18
had the lowest death rates. Researchers from the California Department
of Public Health looked at 1088 cases of hospitalization and death attributed
to [pandemic] H1N1 from 23 Apr 2009, shortly after the virus was discovered,
to 11 Aug 2009. The findings are published in this week's Journal of the
American Medical Association [JAMA 2009; 30(17): 1896-902, 4 Nov: Factors
associated with death or hospitalization due to pandemic 2009 influenza
A (H1N1) infection in California. JK Louie, M Acosta, K Winter, et al;
http://jama.ama-assn.org/cgi/content/abstract/302/17/1896; for Abstract
see comment below. - Mod.CP]
- While hospitalization rates in California were highest
for infants and young adults ages 18 to 29 and lower for older people,
the findings suggest older people who are hospitalized are more likely
to die. "Despite reports that elderly persons may be "protected"
by pre-existing immunity, clinicians should closely monitor and promptly
treat hospitalized patients with pandemic 2009 influenza A H1N1 infection,"
- Still, similar to statistics collected by the federal
Centers for Disease Control and Prevention (CDC), data in California show
[that pandemic] H1N1 is hitting young people harder than what's typically
seen for seasonal flu. The median age of hospitalized patients in California
was 27. Of the 1088 hospitalization and death reports in California, 118
were deaths, which translates into a fatality rate of 11 per cent, researchers
said. For people age 50 and older, the fatality rate was as high as 20
per cent. 8 of the 118 deaths were reported in children younger than age
18, whereas the remainder were in people age 18 and older. The most common
causes of death were viral pneumonia and acute respiratory distress syndrome,
which are complications of influenza.
- The proportion of deaths seen over the spring and summer
in California differs from a recent analysis conducted by the CDC involving
292 deaths reported by 28 states from 30 Aug 2009 to 10 Oct 2009. The percentage
of deaths in people age 24 and younger was 24 per cent, and in those ages
25 to 64, it was 64 per cent. 12 per cent of the deaths occurred in people
age 65 and older.
- communicated by ProMED-mailrapporteur Mary Marshall
- [The higher death rate in the hospitalised elderly in
the state of California may be a consequence of a higher rate of comorbidities
peculiar to the inhabitants of that state. As elsewhere, the pattern remains
true that that the elderly appear to be less susceptible to infection by
the pandemic (H1N1) 2009 virus than the younger age groups, possibly due
to protection by preexisting immunity.
- The abstract of the JAMA paper referred to above reads
- "Context: Pandemic influenza A (H1N1) emerged rapidly
in California in April 2009. Preliminary comparisons with seasonal influenza
suggest that pandemic 2009 influenza A (H1N1) disproportionately affects
younger ages and causes generally mild disease. "Objective: To describe
the clinical and epidemiologic features of pandemic 2009 influenza A (H1N1)
cases that led to hospitalization or death. "Design, setting, and
participants: Statewide enhanced public health surveillance of California
residents who were hospitalized or died with laboratory evidence of pandemic
2009 influenza A (H1N1) infection reported to the California Department
of Public Health between [23 Apr and 11 Aug 2009].
- "Results: During the study period there were 1088
cases of hospitalization or death due to pandemic 2009 influenza A (H1N1)
infection reported in California. The median age was 27 years (range, younger
than 1-92 years) and 68 per cent (741/1088) had risk factors for seasonal
influenza complications. 66 per cent (547/833) of those with chest radiographs
performed had infiltrates and 31 per cent (340/1088) required intensive
care. Rapid antigen tests were falsely negative in 34 per cent (208/618)
of cases evaluated. Secondary bacterial infection was identified in 4 per
cent (46/1088). 21 per cent (183/884) received no antiviral treatment.
Overall fatality was 11 per cent (118/1088) and was highest (18-20 per
cent) in persons aged 50 years or older. The most common causes of death
were viral pneumonia and acute respiratory distress syndrome.
- "Conclusions: In the 1st 16 weeks of the current
pandemic, the median age of hospitalized infected cases was younger than
is common with seasonal influenza. Infants had the highest hospitalization
rates and persons aged 50 years or older had the highest mortality rates
once hospitalized. Most cases had established risk factors for complications
of seasonal influenza."
- The HealthMap/ProMED-mail interactive map of California
can be accessed at <http://healthmap.org/r/00aj>http://healthmap.org/r/00aj.
- Patricia A. Doyle DVM, PhD Bus Admin, Tropical Agricultural
Economics Univ of West Indies Please visit my "Emerging Diseases"
message board at: http://www.emergingdisease.org/phpbb/index.php Also
my new website: http://drpdoyle.tripod.com/ Zhan le Devlesa tai
sastimasa Go with God and in Good Health