*Mortality data in this table are voluntarily reported from 121 cities in the United states, most of which have populations of 100,000 or more. A death is reported by the place of its occurrence and by the week that the death certificate was filed. Fetal deaths are not included.

**Pneumonia and influenza.

†Because of changes in reporting methods in these 3 Pennsylvania cities, these numbers are partial counts for the current week. Complete counts will be available in 4 to 6 weeks.

††Total includes unknown ages.

§Data not available. Figures are estimates based on average of past 4 weeks.

TABLE V. Estimated years of potential life lost (YPLL) before age 65* and causespecific mortality, by cause of death United States, 1986

*For details of calculation, see MMWR Supplement, Premature Mortality in the United States, December 19, 1986, Vol. 35, No. 2S. Cause-specific mortality rates for 1986 were obtained from the National Center for Health Statistics, Monthly Vital Statistics Report (MVSR), Vol. 35, No. 13, August 24, 1987. Cause-specific deaths for 1985 were obtained from the MVSR, Vol. 36, No. 5, Supplement, August 28, 1987. Age-specific population estimates for 1985 and 1986 were obtained from the Bureau of the Census, Estimates of the Population of the United States by Age, Sex, and Race: 1980 to 1986, Series P-25, No. 1000.

*Cause-specific mortality rates as reported in the National Center for Health Statistics' Monthly Vital Statistics Report are compiled from a 10% sample of all deaths.

Equivalent to accidents and adverse effects.

"Category derived from disorders relating to short gestation and respiratory distress syndrome. **Reflects CDC surveillance data.

occasion resulted in diminished vaccine efficacy, such as the failure of A/Port Chalmers/1/73 to protect against AVictoria/3/75 (2). However, reduced vaccine efficacy has not always occurred in such situations. In 1972, vaccine containing A/Aichi/2/68 reduced cases of influenza by 60% in an outbreak caused by the antigenic drift variant A/England/42/72 (3), and, in 1977, A/Victoria/3/75 vaccine protected adults from A/Texas/1/77 infection with 80% efficacy (4). The mechanism of such cross (heterovariant) protection is not precisely known. Although antigenic variants differ in some epitopes on the hemagglutinin, they also share other common hemagglutinin epitopes. Because type A(H3N2) viruses have circulated since 1968, most of the population has been primed by previously circulating strains and is, therefore, more responsive to heterovariant immunization. In addition, the antigenic changes described occurred in the hemagglutinin surface glycoprotein. Significant protection from illness may also be induced by the neuraminidase surface glycoprotein (5,6), which has shown less evidence of antigenic drift. Still other factors, such as the capacity of a strain to spread in the population, can emerge independently from changes in the antigenic properties of the hemagglutinin. Therefore, vaccine efficacy cannot be determined until placebo-controlled double-blind trials have been completed.

Nevertheless, laboratory studies, as well as preliminary observations during outbreaks of influenza A(H3N2) among high-risk residents of nursing homes, suggest that the A/Leningrad/360/86 component of the current vaccine may not provide optimal protection against presently circulating strains. These findings emphasize the need for health-care providers to be aware of the recommendations for use of the antiviral drug amantadine for controlling outbreaks and for prophylaxis or treatment of unprotected patients (7). Because amantadine, which is a prescription drug, must be given before exposure to prevent infection or within the first 1 or 2 days after onset of illness for treatment, contingency plans for its rapid use are needed. These plans include obtaining a physician's order to give the drug to high-risk patients at the first signs of influenza illness, knowing the precautions concerning dosage of the drug (particularly for persons with known renal insufficiency or with presumed reduced renal function, such as those over 64 years of age), and arranging for an adequate supply of the drug.

A fact sheet on amantadine, directed particularly at use in institutions caring for high-risk persons, is available through the Office of Public Inquiries, Centers for Disease Control, 1600 Clifton Road, NE, Atlanta, Georgia 30333.

References

1. Centers for Disease Control. Update: influenza activity - United States. MMWR 1988; 37:49-50.

2. Barker WH, Mullooly JP. Effectiveness of inactivated influenza vaccine among noninstitutionalized elderly persons. In: Kendal AP, Patriarca PA, eds. Options for the control of influenza: proceedings of a Viratek-UCLA symposium held in Keystone, Colorado, April 20-25, 1985. New York: Alan R Liss, Inc, 1985:169-82.

3. Stiver HG, Graves P, Eickhoff TC, Meiklejohn G. Efficacy of "Hong Kong" vaccine in preventing "England" variant influenza A in 1972. New Engl J Med 1973; 289:1267-71.

4. Meiklejohn G, Eickhoff TC, Graves P, I J [sic]. Antigenic drift and efficacy of influenza virus vaccines, 1976-1977. J Infect Dis 1978;138:618-24.

5. Monto AS, Kendal AP. Effect of neuraminidase antibody on Hong Kong influenza. Lancet 1973;1:623-5.

6. Couch RB, Kasel JA, Gerin JL, Schulman JL, Kilbourne ED. Induction of partial immunity to influenza by a neuraminidase-specific vaccine. J Infect Dis 1974;129:411-20.

7. Immunization Practices Advisory Committee. Prevention and control of influenza. MMWR 1987;36:373-80,385-7.

Current Trends

Changes in Premature Mortality

United States, 1979-1986

Premature mortality in the United States, as measured in total years of potential life lost (YPLL) before age 65 (1), has been analyzed for data collected annually since 1979.* The overall trend from 1979 to 1986 was toward lower YPLL and YPLL rates, even though the number and rate of YPLL increased from 1984 to 1986 (Table V, page 45).

The total number of YPLL decreased by 6.0%, and the rate of YPLL per 1,000 persons fell by 13.3% during the period 1979-1986 (Table 1). The greatest absolute rate decline from 1979 to 1986 was in YPLL due to unintentional injuries (Figure 1). The ranking of the leading causes of YPLL changed only slightly from 1979 to 1986, with the exception of the addition of the acquired immunodeficiency syndrome (AIDS) (Table 1). Fewer than five AIDS deaths were recorded in 1979; however, by 1986, AIDS had become the eighth leading cause of YPLL and accounted for 2.0% of total YPLL.

*The period for which U.S. mortality data coded according to the International Classification of Diseases, Ninth Revision, (ICD-9) are available.

TABLE 1. Ranking of leading causes of years of potential life lost (YPLL) before age 65 and percentage of change in rates United States, 1979 and 1986

Cause of Mortality

Premature Mortality - Continued

From 1979 to 1986, the rate of YPLL decreased for ten of the leading causes of death and increased for three. Unintentional injuries accounted for the largest portion of the decrease (30.0%) among the causes of death with rate decreases. Most of the decline in injuries occurred between 1980 and 1982 and is attributable to a decrease in motor vehicle-related deaths in the 15- to 24-year age group. Prematurity (respiratory distress syndrome and disorders relating to short gestation and unspecified low birthweight) had the largest relative decline in rate of YPLL per 1,000 persons. In large part, this decline was due to a greater than one-third reduction in the rate of infant deaths due to respiratory distress syndrome. Prematurity (-17.4%) and diseases of the heart (-14.0%) followed injuries in contributing to the overall decline in YPLL rates from 1979 to 1986.

Reported by: Epidemiologic Studies Br, Div of Surveillance and Epidemiologic Studies, Epidemiology Program Office, CDC.

Reference

1. Centers for Disease Control. Premature mortality in the United States: public health issues in the use of years of potential life lost. MMWR 1986;35(suppl 2S).

FIGURE 1. Rates of years of potenital life lost (YPLL) for causes with rate changes >0.5, by year United States, 1979-1986