Risk of acute respiratory disease among pregnant women during influenza A epidemics.

The medical literature contains little information on the occurrence of excess morbidity among pregnant women during recent influenza epidemics. Rates of medical visits for acute respiratory disease (ARD) among pregnant and nonpregnant members of a large prepaid practice population were examined. Use of medical services for ARD was ascertained for approximately 1,000 pregnant women and 3,000 nonpregnant women during each of four epidemic periods (1975, 1976, 1978, 1979) and a nonepidemic period (1977). Comparing the combined epidemic periods with the nonepidemic period, there were significant excesses of 23.7 (standard error (SE) = 8.1) ARD contacts per 1,000 attributable to epidemic influenza for pregnant women and 10.2 (SE = 3.4) for nonpregnant women. ARD hospitalization rates among pregnant women were low (2 per 1,000), and there were no maternal deaths. The significant ARD excess among pregnant women was concentrated in the 1978 period with reappearance of the A/Russia H1N1 subtype in the community and was confined to those under age 25 who would not have ben previously exposed to this subtype (94.4 (SE = 28.5]. These findings indicate that recent influenza epidemics caused only modest excess ARD morbidity among pregnant women, and significant excess occurred only in association with antigenic shift. These findings support current national policy recommendations with respect to influenza vaccination of pregnant women.

Hysterectomy performed within 1 year after tubal sterilization.

In the United States, approximately 650,000 women of reproductive age undergo tubal sterilization each year and some of these women later have hysterectomies. Little is known about risk factors for having hysterectomy after tubal sterilization. For examination of this issue, we analyzed data from the Collaborative Review of Sterilization, an ongoing multicenter prospective study designed to assess the safety and efficacy of female sterilization operations. In 1979 and 1980, 4002 women 15 to 44 years of age had interval tubal sterilization; of these women, 64 had hysterectomies within 15 months, which yielded a cumulative incidence of 1.6%. Women with a history of menstrual complaints, leiomyomata, ovarian cysts, or endometriosis before their tubal sterilization had an increased risk of hysterectomy, compared with women without such a history. However, 98% of women with a history of these conditions did not have a hysterectomy within 15 months after tubal sterilization. Further follow-up of these women should help to better delineate their long-term risks.

Cumulative prevalence rates and corrected incidence rates of surgical sterilization among women in the United States, 1971--1978.

The authors used data from the 1970 National Fertility Survey and Centers for Disease Control surveillance of surgical sterilizations to estimate the cumulative prevalences of hysterectomy and tubal sterilization among women of reproductive age in the United States between 1971 and 1978. In 1978, the cumulative prevalence rate of tubal sterilization was more than twice as high for women aged 15--44 years as it was in 1971 and at least three times as high for women under 30. Although the increase in the cumulative prevalence rate of hysterectomy was not as marked, by 1978, 19% of women aged 40--44 had undergone hysterectomy. The authors used the cumulative prevalence rate to estimate the population at risk for surgical sterilization, and calculated the corrected incidence rates for these procedures. While corrected incidence rates of tubal sterilization among women aged 15--44 doubled between 1971 and 1978, corrected hysterectomy rates remained stable. The largest age-specific increase in incidence rates of tubal sterilization was among women 40--44, with rates six times higher in 1978 than in 1971. These findings can be used to recompute incidence rates of endometrial and cervical cancers, abortions, and ectopic pregnancies, allowing more precise analysis of related trends.

Hospitalizations for measles, 1970-78.

The National Hospital Discharge Survey of the National Center for Health Statistics was analyzed for measles hospitalizations. From 1970-1978 there were an estimated 52,301 hospitalizations for measles, or approximately 5,800 per year. The median patient age was three years, and the median length of stay was four days. Forty-one per cent of the discharges listed respiratory complications, 10 per cent listed otitis media, and 3 per cent listed neurologic complications. Based on this analysis, hospitalizations for measles accounted for 314,063 hospital days during the period 1970-1978.

Mortality data analysis using a multiple-cause approach.

Death certificates are the primary source for information used to define general mortality patterns in the United States. Analyses of mortality data generally are restricted to one of the conditions listed on the certificate--the underlying cause of dealth. We review principles related to the use of mortality data and describe a study using mortality tapes ("multiple-cause tapes") that list all conditions recorded on dealth certificates. Using multiple-cause tapes, we found that the number of deaths associated with seven infectious diseases in 1968, 1969, and 1970 was from 24% (diphtheria) to 81% (rubella) greater than that officially reported. Multiple-cause tapes also permitted a review of the association of deaths attributed to measles and varicella and known complications of these diseases. these observations confirm the usefulness of multiple-cause tapes in analyzing mortality data and emphasize the importance of examining all conditions listed on the death certificate.

Abscesses complicating DTP vaccination.

Reports of abscesses after the use of diphtheria and tetanus toxoids and pertussis vaccine (DTP vaccine) from two different lots (No. 1 and 2) of a single manufacturer (manufacturer A) prompted an investigation into the rates of abscess formation following the use of DTP vaccine from several different manufacturers. A total of 74 abscesses for lot 1, 16 for lot 2, and three for other DTP products was uncovered. The overall rate after lots 1 and 2 was 1.1 per 1,000 doses administered compared with 0.01 per 1,000 doses for DTP vaccine from other manufacturers (P less than .0001). Faulty technique, site and route of inoculation, microbiologic contamination, and hypersensitivity were ruled out as likely explanations for the increase in abscesses among recipients of DTP vaccine from manufacturer A. Use of a single needle to withdraw vaccine from the vial and to inoculate the vaccinees, combined with high aluminum adjuvant content in the implicated vaccine, may have led to an increased rate of abscess formation.

Influenza and influenza vaccination.

The hemagglutinin and neuraminidase surface antigens of the influenza virus periodically undergo major or minor structural changes. These influence epidemiologic patterns and the composition of vaccine. Annual vaccination is recommended for individuals at increased risk of complications from lower respiratory tract infections. Vaccine for 1979-80 contains antigens representative of three viruses and is closely related to the vaccine of 1978-79. Amantadine is approved for prophylaxis and treatment.