Investigations of 2 cases of diphtheria-like illness due to toxigenic Corynebacterium ulcerans.

BACKGROUND: We present 2 case reports in the United States and investigations of diphtheria-like illness caused by toxigenic Corynebacterium ulcerans. A fatal case occurred in a 75-year-old male Washington resident who was treated with clindamycin but did not receive equine diphtheria antitoxin. A second, nonfatal case occurred in a 66-year-old female Tennessee resident who received erythromycin and diphtheria antitoxin. METHODS: Both case patients and close human and animal contacts were investigated by their respective state health departments. RESULTS: C. ulcerans isolated from the patient who died was resistant to erythromycin and clindamycin. For both isolates, conventional polymerase chain reaction results were positive for A and B subunits of diphtheria toxin gene tox, and modified Elek tests confirmed toxin production. The source of infection remained undetermined for both cases. Neither patient was up-to-date with diphtheria toxoid vaccination. CONCLUSION: These case reports highlight the importance of early treatment with diphtheria antitoxin, the selection of effective antimicrobial agents, and prevention through up-to-date vaccination.

Influenza 2004--2005: the best of times, the worst of times.

Last year's flu vaccine shortage caught public health officials around the country off guard. Minnesota's efforts to locate vaccine within the state and distribute extra doses to areas with the greatest need paid off, as the state was able to make vaccinations available to people who were at greatest risk--and eventually to everyone else--long before the rest of the country. This article looks at how officials in Minnesota handled the situation and how better communication and development of a Web-based data collection tool to assess and project the supply of vaccine could better prepare the state for another shortage.

Infant pertussis: who was the source?

BACKGROUND: In the United States in the 1990s, the incidence of reported pertussis in adults, adolescents and infants increased; infants younger than 1 year of age had the highest reported incidence. METHODS: In 4 states with Enhanced Pertussis Surveillance, we examined the epidemiology of reported pertussis cases to determine the source of pertussis among infants. A source was defined as a person with an acute cough illness who had contact with the case-infant 7-20 days before the infant's onset of cough. RESULTS: The average annual pertussis incidence per 100,000 infants younger than 1 year of age varied by state: 22.9 in Georgia; 42.1 in Illinois; 93.0 in Minnesota; and 35.8 in Massachusetts. Family members of 616 (80%) of 774 reported case-infants were interviewed; a source was identified for 264 (43%) of the 616 case-infants. Among the 264 case-infants, mothers were the source for 84 (32%) and another family member was the source for 113 (43%). Of the 219 source-persons with known age, 38 (17%) were age 0-4 years, 16 (7%) were age 5-9 years, 43 (20%) were age 10-19 years, 45 (21%) were age 20-29 years and 77 (35%) were age > or =30 years. CONCLUSIONS: The variation in reported pertussis incidence in the 4 states might have resulted from differences in awareness of pertussis among health care providers, diagnostic capacity and case classification. Among case-infants with an identifiable source, family members (at any age) were the main source of pertussis. Understanding the source of pertussis transmission to infants may provide new approaches to prevent pertussis in the most vulnerable infants.

Pertussis vaccine effectiveness among children 6 to 59 months of age in the United States, 1998-2001.

BACKGROUND: Despite the dramatic pertussis decrease since the licensure of whole-cell pertussis (diphtheria-tetanus toxoids-pertussis [DTP]) vaccines in the middle 1940s, pertussis remains endemic in the United States and can cause illness among persons at any age; >11000 pertussis cases were reported in 2003. Since July 1996, in addition to 2 DTP vaccines already in use, 5 acellular pertussis (diphtheria-tetanus toxoids-acellular pertussis [DTaP]) vaccines were licensed for use among infants; 3 DTaP vaccines were distributed widely during the study period. Because of the availability of 3 DTaP and 2 DTP vaccines and the likelihood of the vaccines being used interchangeably to vaccinate children with the recommended 5-dose schedule, measuring the effectiveness of the pertussis vaccines was a high priority. OBJECTIVE: To measure the pertussis vaccine effectiveness (VE) among US children 6 to 59 months of age. DESIGN: We conducted a case-control study in the Cincinnati, Ohio, metropolitan area, Colorado, Idaho, and Minnesota. PARTICIPANTS: Confirmed pertussis cases among children 6 to 59 months of age at the time of disease onset, with onset in 1998-2001, were included. For each case subject, 5 control children were matched from birth certificate records, according to the date of birth and residence. OUTCOME MEASURES: A standardized questionnaire was used to obtain vaccination data from parents and providers. Parents/guardians were asked about demographic characteristics, child care attendance, the number of household members who stayed at the same home as the enrolled child for > or =2 nights per week, and cough illness of > or =2-week duration among these household members in the month before the case patient's cough onset. Pertussis vaccine doses among case children were counted as valid if they were received > or =14 days before the cough onset date ("valid period"). The age of the case patient (in days) at the end of the valid period was determined, and doses of vaccine for the matched control subjects were counted as valid if they were received by that age. Conditional logistic regression models were used to estimate the matched odds ratios (ORs) for pertussis according to the number of pertussis vaccine doses. The VE was calculated with the following formula: (1 - OR) x 100. Because the pertussis antigen components or amounts differed according to vaccine, the VE of 3 or 4 doses of DTP and/or DTaP was estimated according to the recorded vaccine manufacturer and vaccine type. RESULTS: All enrolled children (184 case subjects and 893 control subjects) had their vaccine history verified. The proportions of children who received 0, 1 or 2, 3, and > or =4 pertussis (DTP and/or DTaP) vaccine doses among case subjects were 26%, 14%, 26%, and 34% and among control subjects were 2%, 8%, 33%, and 57%, respectively. Compared with 0 doses, the unadjusted VE estimate for 1 or 2 pertussis doses was 83.6% (95% confidence interval [CI]: 61.1-93.1%), that for 3 doses was 95.6% (95% CI: 89.7-98.0%), and for > or =4 doses was 97.7% (95% CI: 94.7-99.0%). Among children who received 4 pertussis vaccinations, the risk of pertussis was slightly higher among those who received only 1 type of vaccine (either 4 DTP doses or 4 DTaP doses), compared with those who received a combination of DTP for doses 1 to 3 and DTaP for dose 4 (OR: 2.4; 95% CI: 1.1-5.2). Among children who received 3 or 4 DTaP vaccine doses, the risk of pertussis was slightly higher among those who received a DTaP vaccine with 4 pertussis antigen components (a vaccine no longer available), compared with those who received the DTaP vaccine with 2 pertussis antigen components (OR: 2.5; 95% CI: 1.1-5.8). Among children who received 4 doses, the risk of pertussis was 2.7 times higher for children who received dose 4 early (age of < or =13 months), compared with children who received dose 4 at an older age (age of > or =14 months) (95% CI: 1.1-6.8). For children 6 to 23 months of age, features of household structure were significant risk factors for pertussis. In a multivariate model, compared with living with an older parent (> or =25 years of age), not living with an "other" household member (a relative other than a parent or sibling or a nonrelated person), and not living with a sibling 6 to 11 years of age, the risk of pertussis for children 6 to 23 months of age was 6.8 times higher if they lived with a young parent (< or =24 years of age) (95% CI: 3.1-15.0), 2.5 times higher if they lived with an "other" household member (95% CI: 1.2-5.4), and 2.2 times higher if they lived with a sibling 6 to 11 years of age (95% CI: 1.2-4.3). Adjusting for these risk factors did not change the VE. Compared with control children, case children were significantly more likely to live with a household member (representing all age groups and relationships) who reported a recent cough illness with duration of > or =2 weeks (87 [52%] of 168 case subjects, compared with 79 [8%] of 860 control subjects). CONCLUSIONS: Any combination of > or =3 DTP/DTaP vaccine doses for children 6 to 59 months of age was highly protective against pertussis. However, there were differences according to vaccine type (DTaP or DTP) and DTaP manufacturer. Among children who received 4 pertussis vaccine doses, a combination of 3 DTP doses followed by 1 DTaP dose had a slightly higher VE than other combinations; among children who received 3 or 4 DTaP vaccine doses, 1 DTaP vaccine performed less well. The finding that pertussis dose 4 was more effective when given to children at > or =14 months of age might be confounded if health care providers were more likely to vaccinate children at 12 months of age because of a perceived risk of undervaccination and if these same children were also at higher risk for pertussis. Household members of any age group and relationship could have been the source of pertussis, and household structure was associated with risk for pertussis for children 6 to 23 months of age. In contrast to control children in the study, 26% of case children had never been vaccinated against pertussis. Unvaccinated children are at risk for pertussis and, in a community with other unvaccinated children, can lead to community-wide pertussis outbreaks. Parents need to be educated about the morbidity and mortality risks associated with Bordetella pertussis infection, and they need to be encouraged to vaccinate their children against pertussis on time and with the recommended number of vaccine doses for optimal protection.

An elementary school outbreak of varicella attributed to vaccine failure: policy implications.

BACKGROUND: Since licensure in the United States, studies have shown that varicella vaccine's overall effectiveness ranges from 44% to 100%, with substantial protection against moderate and severe varicella; however, breakthrough illness has been documented in up to 56% of vaccinated individuals. METHODS: A varicella outbreak occurred in a Minnesota school with 319 students. Phone surveys were conducted with students' parents. Information was collected on students who had recent varicella infections, including onset date, rash characteristics, duration, and underlying medical conditions. RESULTS: Fifty-four cases occurred after a primary breakthrough case. Twenty-nine (53%) students had been vaccinated. Unvaccinated students had an increased risk of moderate varicella, compared with vaccinated students (relative risk [RR], 4.4 [95% confidence interval [CI], 2.2-9.1]; P<.001). The vaccine was 56% effective at preventing any varicella and 90% effective against moderate illness. Students vaccinated >or=5 years before the outbreak had a greater risk of breakthrough varicella than did those vaccinated within

An outbreak of measles among unvaccinated young adults and measles seroprevalence study: implications for measles outbreak control in adult populations.

Measles incidence has declined significantly in the United States since the 1989-1991 resurgence. Several conditions, including pockets of underimmunization, international importation, and the inability to rapidly detect and contain cases, represent potential threats to this success. During the 1995-1996 winter holiday season, the Minnesota Department of Health investigated an outbreak of measles among unvaccinated young adults affiliated with a religious community. A total of 26 outbreak-associated cases of measles were identified; most case patients (65%) were 20-29 years of age (range, 18 months to 35 years). Although case patients had multiple opportunities to expose the general public, no subsequent transmission was identified despite extensive surveillance efforts. A measles seroprevalence survey of 508 Minnesota blood donors aged 20-39 years was conducted; 91% had serological evidence of immunity to measles. Our findings illustrate that high levels of population immunity can prevent transmission of measles, despite multiple opportunities for exposure.