A large rubella outbreak with spread from the workplace to the community.

CONTEXT: Childhood vaccination has reduced rubella disease to low levels in the United States, but outbreaks continue to occur. The largest outbreak in the past 5 years occurred in Nebraska in 1999. OBJECTIVES: To examine risk factors for disease, susceptibility of the risk population, role of vaccine failure, and the need for new vaccination strategies in response to the Nebraska rubella outbreak. DESIGN, SETTING, AND PATIENTS: Investigation of 83 confirmed rubella cases occurring in Douglas County, Nebraska, between March 23 and August 24, 1999; serosurvey of 413 pregnant women in the outbreak locale between October 1998 and March 1999 (prior to outbreak) and April and November 1999 (during and after outbreak). MAIN OUTCOME MEASURES: Case characteristics, compared with that of the general county population; area childhood rubella vaccination rates; and susceptibility among pregnant women before vs during and after the outbreak. RESULTS: All 83 rubella cases were unvaccinated or had unknown vaccination status and fell into 3 groups: (1) 52 (63%) were young adults (median age, 26 years), 83% of whom were born in Latin American countries where rubella vaccination was not routine. They were either employed in meatpacking plants or were their household contacts. Attack rates in the plants were high (14.4 per 1000 vs 0. 19 per 1000 for general county population); (2) 16 (19%), including 14 children (9 of whom were aged <12 months) and 2 parents, were US-born and non-Hispanic, who acquired the disease through contacts at 2 day care facilities (attack rate, 88.1 per 1000); and (3) 15 (18%) were young adults (median age, 22 years) whose major disease risk was residence in population-dense census tracts where meatpacking-related cases resided (R(2) = 0.343; P<.001); 87% of these persons were born in Latin America. Among pregnant women, susceptibility rates were 13% before the outbreak and 11% during and after the outbreak. Six (25%) of 24 susceptible women tested were seropositive for rubella IgM. Rubella vaccination rates were 90.2% for preschool children and 99.8% for school-aged children. CONCLUSIONS: A large rubella outbreak occurred among unvaccinated persons in a community with high immunity levels. Crowded working and living conditions facilitated transmission, but vaccine failure did not. Workplace vaccination could be considered to prevent similar outbreaks. JAMA. 2000;284:2733-2739.

Does reminder-recall augment the impact of voucher incentives on immunization rates among inner-city infants enrolled in WIC? Special Supplemental Program for Women, Infants, and Children.

Inner-city infants (n = 565) enrolled in the WIC program were randomly assigned at 6 months of age to either of 2 groups: (1) voucher incentive (frequency of issuance of food vouchers based on immunization status) plus reminder-recall (calls and/or letters to families of under-vaccinated children) or (2) voucher incentive alone. At 12 months, both groups' immunization levels were high and not significantly different: 80% +/- 4% versus 79% +/- 5% (P =.749).

Estimates of morbidity and mortality rates for diarrheal diseases in American children.

Although the importance of diarrhea as a prime cause of morbidity and death in developing countries is well recognized, the disease burden in the United States has never been thoroughly examined. We have prepared national estimates of the annual number of cases of diarrhea in children less than 5 years of age and of the outcome, measured in terms of visits to a physician, hospitalizations, and deaths. The annual number of diarrheal episodes was estimated by reviewing longitudinal studies of childhood diarrhea conducted in the United States and extrapolating these data to the nation. Estimates of physician visits, hospitalizations, and deaths were prepared from a variety of national data sources. We estimate that 16.5 million children less than 5 years of age have between 21 and 37 million episodes of diarrhea annually. Of these, 2.1 to 3.7 million episodes lead to a physician visit, a total of 220,000 patients are hospitalized, and 325 to 425 children die. The major cost of diarrhea lies in the high numbers and cost of hospitalizations, because approximately 10.6% of hospitalizations in this age group are for diarrhea. Diarrheal deaths occur in relatively small numbers, are more common in the South and among black persons, are potentially avoidable, and could represent as much as 10% of the preventable postneonatal infant death in the United States. These estimates underscore the extensive burden of diarrheal illness in children in the United States and suggest that interventions to prevent disease or decrease its severity could be cost-effective.

Annual rotavirus epidemic patterns in North America. Results of a 5-year retrospective survey of 88 centers in Canada, Mexico, and the United States. Rotavirus Study Group.

Rotavirus is the major cause of severe diarrhea in children. A recent study of hospitalizations for diarrhea in the United States suggested that the annual rotavirus epidemic may follow a regional sequence from west to east. As part of a program to establish active surveillance of rotavirus prior to the introduction of vaccines, we obtained 5 years of retrospective data on rotavirus detections from 88 centers throughout North America. Analysis of 34,644 detections indicates that the peak of the annual rotavirus epidemic occurs first in Mexico and the Southwest of the United States in late fall, goes systematically across the continent in the winter, and ends in the Northeast United States and the Maritime Provinces of Canada in the spring. When detections are grouped by region, onset of the epidemic follows the same regional sequence as the peak. To our knowledge, this is the only description of a repetitive geographic sequence for the seasonal epidemic activity of a viral agent. Further studies are indicated to determine whether climate, features of the virus itself, or other factors are responsible for this apparently unique pattern. A system of active surveillance can use this pattern to detect natural alterations in the epidemic behavior of rotavirus and to assess the impact of vaccines.

Variabilidad estacional mundial de las infecciones por rotavirus / Global seasonality of rotavirus infections

Global seasonability of rotavirus infections

Se publica en ingles en: Bull. WHO 68(2), 1990