The epidemiology of listeriosis in the United States--1986. Listeriosis Study Group.

To determine the morbidity and mortality due to listeriosis in the United States, the authors undertook an active surveillance project in 1986 to identify all cases in which Listeria monocytogenes was isolated from cultures of ordinarily sterile sites in a population of 34 million persons. The authors estimated that at least 1,700 cases of listeriosis and 450 deaths occurred in the United States in 1986; 27% of these cases occurred in pregnant women, with 22% of perinatal cases resulting in stillbirths or neonatal deaths. The risk of listeriosis in adults (0.5 per 100,000 population) was similar in all regions studied; the incidence of perinatal listeriosis was three times higher in Los Angeles County, California, than in the other areas (24.3/100,000 live births vs. 7.8/100,000 live births). Geographic variation may have resulted from underdiagnosis of perinatal listeriosis in five of the study areas. Multilocus electrophoretic enzyme typing was useful for elucidating the molecular epidemiology of L. monocytogenes; perinatal listeriosis was significantly associated with one group of related strains. Multilocus electrophoretic enzyme typing also identified three clusters representing possible common-source outbreaks. These findings document the substantial morbidity due to listeriosis in the United States; to the extent that sporadic listeriosis is foodborne, this morbidity could be reduced by appropriate preventive measures, particularly in persons known to be at increased risk of infection.

Bacterial meningitis in the United States, 1986: report of a multistate surveillance study. The Bacterial Meningitis Study Group.

A prospective, laboratory-based surveillance project obtained accurate data on meningitis in a population of 34 million people during 1986. Haemophilus influenzae was the most common cause of bacterial meningitis (45%), followed by Streptococcus pneumoniae (18%), and Neisseria meningitidis (14%). Rates of H. influenzae meningitis varied significantly by region, from 1.9/100,000 in New Jersey to 4.0/100,000 in Washington state. The overall case fatality rates for meningitis were lower than those reported in several studies from the early 1970s, suggesting that improvements in early detection and antibiotic treatment may have occurred since that time. Concurrent surveillance was also performed for all invasive disease due to the five most common causes of bacterial meningitis. Serotypes of group B streptococcus other than type III caused more than half of neonatal group B streptococcal disease and mortality, suggesting that an optimal vaccine preparation must be multivalent. Of the organisms evaluated, group B streptococcus was the second most common cause of invasive disease in persons greater than 5 years old.

Active surveillance for toxic shock syndrome in the United States, 1986.

Active surveillance for toxic shock syndrome (TSS) was established in 1986 in Los Angeles County and in the states of Missouri, New Jersey, Oklahoma, Tennessee, and Washington. Case reports were solicited through biweekly contact with all acute-care hospitals. One hundred sixteen definite and 63 probable cases were reported; 85% of the cases occurred in female patients and 15% in male patients. Among cases in females, 83 (55%) were menstrual; the mean age of the patients with menstrual cases was 23 years (range, 12-46 years). The overall incidence of TSS was 0.53/100,000. The cumulative incidence varied significantly by region, ranging from 1.23/100,000 in Oklahoma to 0.22/100,000 in New Jersey (P = .0001); the incidence in all other areas ranged from 0.39/100,000 to 0.70/100,000. The incidence of menstrual TSS was 1.05/100,000 women 15-44 years of age and peaked in women between the ages of 15 and 19 years at 1.52/100,000. The incidence was higher in whites than in nonwhites for both menstrual TSS (1.21/100,000 vs. 0.34/100,000, P = .002) and nonmenstrual TSS (0.30/100,000 vs. 0.14/100,000, P = .031). Our data indicate that TSS continues to be a cause of morbidity. Although there is underreporting in national passive surveillance, the proportion of menstrual cases reported through active surveillance was similar to that reported to the passive system in 1986.

Risk factors for menstrual toxic shock syndrome: results of a multistate case-control study.

For assessment of current risk factors for developing toxic shock syndrome (TSS) during menstruation, a case-control study was performed. Cases with onset between 1 January 1986 and 30 June 1987 were ascertained in six study areas with active surveillance for TSS. Age-matched controls were selected from among each patient's friends and women with the same telephone exchange. Of 118 eligible patients, 108 were enrolled, as were 185 "friend controls" and 187 telephone exchange-matched controls. Tampon use was a risk factor for developing TSS during menstruation (odds ratio = 29; 95% confidence interval = 7-120), and risk increased with increasing tampon absorbency (odds ratio = 1.34 per gram increase in absorbency; 95% confidence interval = 1.2-1.6). The role of tampon chemical composition could not be assessed because the number of cases was inadequate. Neither use of birth control pills for contraception nor use of medications for premenstrual or menstrual symptoms protected against or was a risk factor for the development of menstrual TSS.

Nonmenstrual toxic shock syndrome associated with barrier contraceptives: report of a case-control study.

Use of barrier contraceptives has been hypothesized to be a risk factor for nonmenstrual toxic shock syndrome (TSS). This association was evaluated in a case-control study of nonmenstrual TSS; cases were identified through an active surveillance system for TSS during 1986 and 1987. Potential risk factors for nonmenstrual TSS were compared for 28 patients and 100 age-matched controls. Use of barrier contraceptives was associated with a significantly increased risk of nonmenstrual TSS, with matched odds ratios of 10.5 and 11.7 for contraceptive sponge and diaphragm use, respectively. Use of nonbarrier contraceptive methods was unrelated to nonmenstrual TSS. Despite the elevated odds ratio, the incidence of nonmenstrual TSS in barrier contraceptives users and the risk of nonmenstrual TSS attributable to barrier contraceptive use are low. Clinicians and women who use barrier contraceptives should be aware of this rare but potentially fatal complication; however, other considerations, such as efficacy and complications associated with other types of contraception, may be more important in the choice of a contraceptive method.

Association of sporadic listeriosis with consumption of uncooked hot dogs and undercooked chicken.

In 1986-87 the Centers for Disease Control conducted an active population-based survey of Listeria monocytogenes infections in six regions of the United States. Listeriosis was reported in 154 patients: one-third of cases were perinatal and the remaining two-thirds occurred in the elderly and immunosuppressed. 28% of cases were fatal. 82 cases and 239 controls matched for age and underlying disease were enrolled in a study of risk factors for listeriosis. Cases were significantly more likely than controls to have eaten uncooked hot dogs or undercooked chicken, with 20% of the overall risk of listeriosis attributable to consumption of these foods. No other risk factors were identified.

A day care-based study of the efficacy of Haemophilus b polysaccharide vaccine.

To assess the efficacy of the Haemophilus b polysaccharide vaccine following licensure and to evaluate the risk of Haemophilus influenzae type b (Hib) disease in the week following vaccination, we conducted a day care-based case-control efficacy study using cases of invasive Hib disease ascertained through active surveillance in areas with a total population of 34 million. For each patient 18 to 59 months old, up to three 18- to 59-month-old controls were chosen from the same day care classroom. Using conditional logistic regression, the vaccine efficacy was estimated to be 45% (95% confidence interval = -1% to 70%) and did not change significantly after accounting for potential biases. In addition, three (3%) of 104 patients vs five (2%) of 207 controls were vaccinated within seven days before the patients' dates of admission (odds ratio = 1.8, 95% confidence interval = 0.3 to 10.2), which does not suggest an increased risk of Hib disease in the week following immunization. This study suggests that the efficacy of the currently used HBPV is less than expected from previous studies and points out the usefulness of case-control studies for monitoring vaccine efficacy following licensure.

Chronic gonadotropin-releasing hormone agonist treatment suppresses ovulation and sexual behavior in group-living female rhesus monkeys.

The sexual behavior of six adult rhesus females was observed with each of four males prior to, during, and following a 90 day treatment with 20 micrograms/day of a gonadotropin releasing-hormone (GnRH) agonist (WY-40972). All females ovulated, approached males and copulated during an untreated cycle. No ovulations occurred during agonist treatment and all females showed reduced sexual interest during the last 25 treatment days. Three females showed elevated estradiol and copulated during the first 10 days of agonist treatment, but never showed similar levels of estradiol or copulation during the rest of treatment. Within 34 days after agonist treatment, all females initiated proximity to males, copulated, and ovulated. All females became pregnant on their second ovulation after agonist treatment. This demonstration that inhibition of ovulation with a GnRH agonist decreased rhesus female sexual initiation, demonstrates the importance of ovarian hormones to female sexual motivation and suggests that the changes in human female sexual interest should be evaluated during the development of agonist-based contraceptives.

Periovulatory changes in female sexual behavior and patterns of ovarian steroid secretion in group-living rhesus monkeys.

The behavior of nine intact group-living adult female rhesus was observed for 30 min daily with each of four adult male rhesus across a verified ovulatory menstrual cycle. Blood samples collected from females daily or on alternate days were analyzed for estradiol, testosterone, and progesterone. Female patterns of approach, follow, and initiate proximity increased several days prior to the estradiol peak, peaked on the day of the estradiol peak, then declined completely or to very low frequencies. Mounts, intromissions, and ejaculations increased significantly on the day of the estradiol peak, remained elevated for 2 more days, then declined completely by the fifth day after peak estradiol. Ejaculations never occurred outside of a 10-day period starting 4 days before the estradiol peak and ending 5 days after the estradiol peak. During this period females initiated over 90% of all approaches. Female hand slap, threaten away, and stand up increased significantly on the first day of increased copulation, remained elevated while copulation was significantly elevated, then decreased along with the decline in copulation. Ten of eleven patterns of female behavior correlated significantly with estradiol level prior to the estradiol peak. All were significantly inversely correlated with progesterone level after the estradiol peak. No pattern of female behavior correlated significantly with testosterone either before or after the estradiol peak. Similarly, male patterns of behavior correlated with female levels of estradiol and progesterone, but not testosterone. These results demonstrate a relationship between increased serum estradiol and increased female initiation of sexual behavior. The finding that some patterns of female behavior increase several days prior to copulation, whereas other behaviors increase coincident with increased copulation suggests that the behavior of group-living rhesus females serves two functions. The first is to communicate sexual interest and the second is to maintain the consort pair and increase the probability that ejaculation will occur. In addition, the strong correlation between preovulatory female behavior and estradiol level suggests that the female's behavior provides precise information about her reproductive state and could thus coordinate copulation with maximal fertility.