MMWR 02/16/96
ghmcleaf{CONTRACTOR/ASPEN/...@ace.aspensys.com
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Centers for Disease Control and Prevention
February 16, 1996
Vol. 45, No. 6
Articles included:
* Update: Mortality Attributable to HIV Infection Among Persons
Aged 25--44 Years --- United States, 1994
* Update: Influenza Activity --- United States, 1995--96 Season
Update: Mortality Attributable to HIV Infection Among Persons Aged
25-44 Years -- United States, 1994
During the 1980s, human immunodeficiency virus (HIV)
infection, the cause of acquired immunodeficiency syndrome (AIDS),
emerged as a leading cause of death in the United States (1). In
1993, HIV infection became the most common cause of death among
persons aged 25-44 years. This report updates national trends in
deaths caused by HIV infection in 1994, which continue to
increase.*
Provisional estimates of deaths in 1993 and 1994 were based on
a 10% sample of death certificates of U.S. residents filed in all
50 states and the District of Columbia (2,3). Demographic data were
reported by funeral directors, and causes of death were reported by
physicians, medical examiners, or coroners and encoded according to
the International Classification of Diseases, Ninth Revision.
Underlying causes of death were classified into the categories in
CDC's "List of 72 Selected Causes of Death" for ranking (2). Rates
were calculated using midyear U.S. population estimates based on
decennial census data compiled by the U.S. Bureau of the Census.
Information on Hispanic ethnicity and races other than white and
black was unavailable in the provisional mortality data; each race
includes Hispanics.
In 1994, an estimated 41,930 U.S. residents died from HIV
infection, a 9% increase over the estimated 38,500 in 1993; of
these, 3% were aged less than 25 years; 72%, 25-44 years; and 25%,
greater than or equal to 45 years. HIV infection was the eighth
leading cause of death overall, accounting for 2% of all deaths.
Among persons aged 25-44 years, HIV infection was the leading cause
of death and accounted for 19% of deaths in this age group. In
1994, HIV infection became the fourth leading cause of years of
potential life lost before age 65 (YPLL-65) (compared with fifth in
1993), accounting for 9% of YPLL-65 from all causes.
Among men aged 25-44 years, HIV infection was the leading
cause of death for all men (23% of deaths) (Figure 1) and for white
and black men (20% and 32% of deaths, respectively). HIV infection
was the third leading cause of death for all women in this age
group (11% of deaths) (Figure 2), the fifth leading cause for white
women (6% of deaths), and the leading cause for black women (22% of
deaths).
In 1994, the death rate from HIV infection per 100,000
population among persons aged 25-44 years was almost four times as
high for black men (177.9) as for white men (47.2) and nine times
as high for black women (51.2) as for white women (5.7). Compared
with 1993, the rate for white men in 1994 was similar (47.5 and
47.2, respectively), and rates for the three other sex-racial
groups continued to increase: the percentage increase was 13% for
black men, 28% for black women, and 30% for white women (Figure 3).
Reported by: Surveillance Br, Div of HIV/AIDS Prevention, National
Center for Prevention Svcs; Mortality Statistics Br, Div of Vital
Statistics, National Center for Health Statistics, CDC.
Editorial Note: This analysis of provisional mortality data for
1993 and 1994 indicates a continuing increase in HIV infection as
a leading cause of death in the United States, particularly among
persons aged 25-44 years. Among persons in this age group, HIV
infection became the most common cause of death for black men in
1991, for all men (all racial/ethnic groups combined) in 1992, and
for white men in 1994. HIV became the third leading cause of death
among women in this age group in 1994. In addition, as reflected by
YPLL-65, HIV infection has become a leading cause of premature
mortality.
Because this analysis was based on the underlying cause of
death recorded on death certificates, the findings in this report
probably underestimate the impact of HIV infection on mortality in
the United States. Previous studies have indicated that, among
persons aged 25-44 years, deaths for which HIV infection was
designated the underlying cause represent approximately two thirds
to three fourths of all deaths attributable to HIV infection (4,5).
The estimated number of death certificates with any mention of HIV
infection (i.e., underlying or nonunderlying cause) in 1994 was
48,000 (CDC, unpublished data, 1995), compared with the
approximately 42,000 on which HIV was listed as an underlying
cause. Based on survival analysis of cases reported to CDC through
the AIDS surveillance system--which includes other sources in
addition to data from death certificates--and the completeness of
reporting of AIDS cases and of deaths, an estimated 55,000 to
60,000 persons with AIDS died in 1994 (CDC, unpublished data,
1995).
Trends in HIV-related mortality reflect changes in the
demographic patterns of the HIV epidemic. For example, from 1993 to
1994, the death rate for HIV infection for white men aged 25-44
years did not change, and rates for women and black men increased;
in 1994, the rate for black women aged 25-44 years surpassed that
for white men in that age group. The increasing death rate for
women affects the care of their children: the estimated 80,000
HIV-infected women of childbearing age who were alive in 1992 will
leave approximately 125,000 to 150,000 children when they die
during the 1990s (6). Racial differences in death rates for HIV
infection probably reflect social, economic, behavioral, and other
factors associated with HIV transmission risks. Such factors are
being addressed through prevention efforts designed to meet the
needs of specific communities (7).
Because of the prolonged period from initial HIV infection to
onset of severe HIV disease (AIDS) (8), recent trends in
HIV-related mortality reflect trends in HIV transmission several
years earlier. Similarly, trends in HIV-related mortality in
several years will indicate, in part, the effectiveness of current
efforts to prevent HIV infection. Despite recent increases in
HIV-related mortality, decreases in the percentages of HIV-related
deaths resulting from particular opportunistic infections
(pneumocystosis, cryptococcosis, and candidiasis) (9) suggest some
success in the treatment and prevention of opportunistic infections
resulting from HIV infection and underscore the importance of
following recently published guidelines for preventing HIV-related
opportunistic infections (10).
References
1. CDC. Update: mortality attributable to HIV infection among
persons aged 25-44 years--United States, 1991 and 1992. MMWR
1993;42:869-72.
2. Singh GK, Mathews TJ, Kochanek K, et al. Annual summary of
births, marriages, divorces, and deaths: United States, 1994.
Hyattsville, Maryland: US Department of Health and Human Services,
Public Health Service, CDC, 1995:18-32. (Monthly vital statistics
report; vol 43, no. 13).
3. NCHS. Annual summary of births, marriages, divorces, and deaths:
United States, 1993. Hyattsville, Maryland: US Department of Health
and Human Services, Public Health Service, CDC, 1994:18-28.
(Monthly vital statistics report; vol 42, no. 13).
4. Buehler JW, Devine OJ, Berkelman RL, Chevarley FM. Impact of the
human immunodeficiency virus epidemic on mortality trends in young
men, United States. Am J Public Health 1990;80:1080-6.
5. Buehler JW, Hanson DL, Chu SY. Reporting of HIV/AIDS deaths in
women. Am J Public Health 1992;82:1500-5.
6. Caldwell MB, Fleming PL, Oxtoby MJ. Estimated number of AIDS
orphans in the United States [Letter]. Pediatrics 1992;90:482.
7. Valdiserri RO, Aultman TV, Curran JW. Community planning: a
national strategy to improve HIV prevention programs. J Community
Health 1995;20:87-100.
8. Alcabes P, Munoz A, Vlahov D, Friedland G. Maturity of human
immunodeficiency virus infection and incubation period of acquired
immunodeficiency syndrome in injecting drug users. Ann Epidemiol
1994;4:17-26.
9. Selik RM, Chu SY, Ward JW. Trends in infectious diseases and
cancers among persons dying from human immunodeficiency virus
infection, United States, 1987-1992. Ann Intern Med 1995;123:933-6.
10. CDC. USPHS/IDSA guidelines for the prevention of opportunistic
infections in persons infected with human immunodeficiency virus:
a summary. MMWR 1995;44(no. RR-8).
*Single copies of this report will be available until February 16,
1997, from the CDC National AIDS Clearinghouse, P.O. Box 6003,
Rockville, MD 20849-6003; telephone (800) 458-5231 or (301)
217-0023.
Update: Influenza Activity -- United States, 1995-96 Season
Influenza activity in the United States increased from late
October through mid- to late December 1995. Although activity began
to decline during January 1996, for the week ending February 3, a
total of 19 states reported continuing regional or widespread
activity*. Influenza type A(H1N1) predominated in all regions
except the Mountain, Pacific, and New England regions, where type
A(H3N2) predominated. Influenza type B accounted for only 1% of all
isolates nationwide.
As of February 3, 1996, of the 19,520 specimens submitted to
World Health Organization collaborating laboratories in the United
States for respiratory virus testing, 2965 (15%) have been positive
for influenza virus: 2925 (99%) were influenza type A, and 40 (1%)
were influenza type B. Of the 1803 type A isolates that have been
subtyped, 1188 (66%) were type A(H1N1) and 615 (34%) were type
A(H3N2). In six of the nine regions in the United States, influenza
type A(H1N1) has accounted for from 64% to 89% of subtyped
influenza type A strains. In the Mountain, Pacific, and New England
regions, influenza type A(H1N1) has circulated at lower levels,
accounting for 41%, 46%, and 48% of subtyped influenza A strains,
respectively.
Regional influenza activity was first reported the week ending
October 28, 1995. The number of states reporting regional or
widespread activity increased each week from November 5 through
December 23, 1995, peaking at 35 states the first week of January
1996. Most outbreaks reported by states to CDC were among
school-aged children. Some outbreaks among elderly persons in
nursing homes also were reported.
The proportion of patients with influenza-like illness (ILI)
who visited 150 U.S. sentinel physicians began to increase the week
ending December 16; this increase continued through December, with
a peak of 7% of total office visits during the week ending December
30. During January, the proportion of patients with ILI began to
decline, reaching 3% by the week ending January 20.
The proportion of deaths attributed to pneumonia and influenza
(P&I) reported from 121 U.S. cities exceeded the epidemic
threshold** by a small margin during three of the eight weeks from
October 29 through December 23, 1995. The proportion of P&I deaths
increased from the week ending December 30 through the week ending
January 20 and began to decline the week ending January 27, but
remained above the epidemic threshold (Figure 1).
Reported by: Participating state and territorial epidemiologists
and state public health laboratory directors. World Health
Organization collaborating laboratories. Sentinel Physicians
Influenza Surveillance System of the American Academy of Family
Physicians. Influenza Br and WHO Collaborating Center for
Surveillance, Epidemiology, and Control of Influenza, Div of Viral
and Rickettsial Diseases, National Center for Infectious Diseases,
CDC.
Editorial Note: Although influenza activity in the United States
peaked during late December 1995, influenza viruses have continued
to circulate through early February 1996. The occurrence of a high
proportion of reported outbreaks among school-aged children is
consistent with patterns during previous influenza seasons when
type A(H1N1) viruses have predominated. Influenza A(H1N1) outbreaks
among children and younger adults can be associated with high
absenteeism in schools and workplaces, and severe secondary medical
complications in a small proportion of infected persons.
Surveillance findings this season suggest that the incidence of
influenza among younger children is substantially higher than
usual. Influenza type A(H1N1) has not predominated in the United
States since the 1986-87 season, and has circulated at low levels
since 1989. As a consequence, a high proportion of children born in
the United States since the late 1980s would not be expected to
have been exposed to type A(H1N1) viruses before this influenza
season.
Despite the ability of type A(H1N1) to cause widespread
outbreaks, since 1977--when type A(H1N1) viruses reemerged after an
absence of 20 years--this strain has not been associated with
substantial morbidity among older adults nor with excess mortality.
In comparison, type A(H3N2) viruses, which emerged in 1968, more
commonly have been associated with excess mortality, greater than
90% of which has occurred among persons aged greater than or equal
to 65 years. Epidemics of influenza type B also have been
associated with excess mortality (1,2). Although the contribution
of type A(H1N1) and type A(H3N2) viruses to the excess P&I
mortality this influenza season cannot be assessed precisely,
observations during previous influenza seasons strongly suggest
that most of these deaths were caused by type A(H3N2) viruses.
References
1. Lui KL, Kendal AP. Impact of influenza epidemics on mortality in
the United States from October 1972 to May 1985. Am J Public Health
1987;77:712-6.
2. Noble GR. Epidemiological and clinical aspects of influenza. In:
Beare AS, ed. Basic and applied research. Boca Raton, Florida: CRC
Press, 1982:11-50.
*Levels of activity are 1) sporadic~sporadically occurring
influenza-like illness (ILI) or culture-confirmed influenza with no
outbreaks detected; 2) regional~outbreaks of ILI or
culture-confirmed influenza in counties with a combined population
of less than 50% of the state's total population; and 3)
widespread~outbreaks of ILI or culture-confirmed influenza in
counties having a combined population of greater than or equal to50%
of the state's total population.
**The epidemic threshold is 1.645 standard deviations above the
seasonal baseline calculated using a periodic regression model
applied to observed percentages since 1983. The baseline was
calculated using a robust regression procedure.