Papers by Kristen Ehresmann
Journal of community health, Jan 7, 2018
Seroepidemiologic studies, which measure serum antibody levels produced in response to infection ... more Seroepidemiologic studies, which measure serum antibody levels produced in response to infection and/or vaccination, can be valuable tools for gaining insight into population level dynamics of infectious diseases. However, because seroepidemiologic studies are expensive and logistically challenging, they are not routinely conducted for surveillance purposes. We have identified a novel venue, state fairgrounds, in which annual sera samples from a population may be rapidly collected with minimal recruitment expenses. We conducted a pilot pertussis seroepidemiologic study over the course of 3 days at the 2016 Minnesota State Fair to determine if this setting, which hosts nearly 2 million visitors over 12 days each year, is viable for facilitating larger seroepidemiologic studies. A total of 104 adults and children were enrolled to provide a finger stick blood sample for serologic testing and to take a written survey regarding recent cough illness and pertussis vaccination. The survey w...
American journal of public health, 2015
We examined the impact of undetected infections, adult immunity, and waning vaccine-acquired immu... more We examined the impact of undetected infections, adult immunity, and waning vaccine-acquired immunity on recent age-related trends in pertussis incidence. We developed an agent-based model of pertussis transmission in Dakota County, Minnesota using case data from the Minnesota Department of Health. For outbreaks in 2004, 2008, and 2012, we fit our model to incidence in 3 children's age groups relative to adult incidence. We estimated parameters through model calibration. The duration of vaccine-acquired immunity after completion of the 5-dose vaccination series decreased from 6.6 years in the 2004 model to approximately 3.0 years in the 2008 and 2012 models. Tdap waned after 2.1 years in the 2012 model. A greater percentage of adults were immune in the 2008 model than in the 2004 and 2012 models. On average, only 1 in 10 adult infections was detected, whereas 8 in 10 child infections were detected. The observed trends in relative pertussis incidence in Dakota County can be attri...
Minnesota medicine
This study evaluated indicators of poverty in Minnesota ZIP code areas with low childhood immuniz... more This study evaluated indicators of poverty in Minnesota ZIP code areas with low childhood immunization rates. During 1996-1997, a retrospective survey of 68,639 Minnesota kindergarten children was conducted; 68% received four doses of diphtheria, tetanus, and pertussis vaccine, three doses of polio vaccine, and one dose of measles, mumps, and rubella vaccine (4:3:1) by 24 months of age. Of 447 ZIP codes further evaluated, 24 (5%; 13 urban and 11 rural) had 4:3:1 immunization rates at 24 months of < or = 50%. None of 159 ZIP codes in which < 5% of residents were below the poverty line had immunization rates < or = 50%, compared with 9 (32%) of 28 ZIP codes with > or = 15% of residents below the poverty line (p < 0.001). Immunization rates were lowest in ZIP codes with a lower median family income and greater proportion of residents below the poverty line. Surveys such as this can help immunization programs target and monitor prevention activities for these pockets of need.
JAMA The Journal of the American Medical Association
Background: During 2008, five children ages 5 months to 3 years were reported to the Minnesota He... more Background: During 2008, five children ages 5 months to 3 years were reported to the Minnesota Health Department (MDH) with invasive Hib disease; one died. Only one of these children had completed their primary Hib series. In December 2007, Merck & Co., Inc. recalled certain lots of their two Hib vaccines and ceased production of both vaccines. As a result, only one hib vaccine manufacturer remained to maintain vaccine supply. It was hypothesized that a shortage of vaccine resulted in lowered Hib vaccination rates leading to an increase in disease. Objectives: To provide a more accurate evaluation of Hib vaccine UTD status from immunization information system (IIS) data Methods: Hib UTD status was evaluated at 9 months of age in two birth cohorts: 11/1/2006 – 3/31/2007 (pre-shortage) and 11/01/2007 – 3/31/2008 (post -shortage). Children having two Merck vaccines at 2 and 4 months were considered up-to-date whereas children having other brands of Hib vaccine needed 3 doses to be cons...
Background: During 2004–2010, pertussis incidence increased 30% among Minnesota preadolescents, w... more Background: During 2004–2010, pertussis incidence increased 30% among Minnesota preadolescents, with an increasing number of outbreaks in schools. We conducted an investigation to gain a greater understanding of pertussis risk factors. Methods: We conducted a case-control study among children aged 7–12 years. Case-patients identified from statewide surveillance were recruited if they met the CSTE definition for probable or confirmed pertussis, with exposure periods during spring and fall school terms of 2010. Control subjects, frequency matched by age, were identified through birth records autopopulated in the Minnesota vaccine registry. Parents were interviewed by telephone. Pertussis vaccination histories were verified with providers. Residence was classified as urban, suburban, or rural by using Census tract-based classification. Exposure odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using logistic regression. Results: We enrolled 1,015 subjects who atten...
The Pediatric Infectious Disease Journal, 2015
Predictors of PCR positivity for pertussis were assessed using Minnesota active surveillance data... more Predictors of PCR positivity for pertussis were assessed using Minnesota active surveillance data. Report of an exposure to pertussis and testing within the optimal time frame of ≤2 weeks were significantly associated with testing PCR positive, emphasizing the importance of asking about epidemiological factors when assessing patients for pertussis, and timely PCR testing.
As part of a 3-year demonstration project to improve pneumococcal polysaccharide vaccine (PPV) co... more As part of a 3-year demonstration project to improve pneumococcal polysaccharide vaccine (PPV) coverage among older adults, the Minnesota Department of Health conducted a baseline evaluation of knowledge, attitudes, and beliefs among the general public regarding PPV. A random-digit dialing telephone survey was conducted among community-dwelling adults age 65 years or older in three metropolitan counties in Minnesota during April through June 1998. Three hundred fifty-three interviews were completed; self-reported PPV coverage was 59% (95% CI 54%, 64%). Nearly all (94%) respondents reported at least one medical visit in the past year. Unvaccinated respondents expressed willingness to be vaccinated if they knew about PPV's safety, dosage, and preventive role. In a final multivariate regression model, factors associated with PPV vaccination included awareness of PPV (OR 7.8; CI 2.1, 29.2; P = 0.002), opinion that receiving PPV is "very important" (OR 8.3; CI 3.2, 21.6; P < 0.001), awareness that Medicare covers PPV (OR 5.1; CI 1.9, 13.8; P = 0.001), physician ever offering PPV (OR 21.7; CI 6.2, 76.6; P < 0.001), and physician regularly offering PPV (OR 3.9; CI 1.1, 13.7; P = 0.03). Respondents were significantly influenced by their physician offering PPV. Therefore, providers' practices are a critical target for improving PPV coverage. Educational efforts to inform patients about PPV and to address misconceptions (e.g., safety, efficacy, Medicare coverage) also may improve vaccination levels.
The Journal of laboratory and clinical medicine, 2003
There is great concern that smallpox could be used for bioterrorism. The disease has a high morta... more There is great concern that smallpox could be used for bioterrorism. The disease has a high mortality rate and can be spread by aerosols, and immunity in the population is low. Although an initial release of smallpox could infect a large number of people, secondary spread would likely be slow because of the long incubation period and the close contact required for transmission. Hospital personnel and household contacts are at the greatest risk of becoming infected. An outbreak of smallpox will be controlled through surveillance, containment, vaccination, and isolation of cases-the strategy used to eradicate the disease globally in 1978. Pre-exposure vaccination is recommended for hospital personnel likely to be exposed to smallpox while caring for patients during an outbreak.
Minnesota medicine, 2013
According to Minnesota Immunization Information Connection (MIIC) data, 23% of Minnesotans were v... more According to Minnesota Immunization Information Connection (MIIC) data, 23% of Minnesotans were vaccinated against 2009 pandemic H1N1 influenza. We analyzed 2009 H1N1 vaccination data at the ZIP code level to learn more about who received the vaccine between 2009 and 2010. We found significant differences in H1N1 vaccination rates by percentage of residents living below the family poverty line, percentage of non-Caucasian residents in a ZIP code and median family income. When stratified by urban or rural location, median family income was significantly associated with vaccination rate only in urban settings; the percentage of non-Caucasians living in an area was significant only in rural settings. In both urban and rural settings, most H1N1 vaccinations were given in a private facility, although the proportion was much higher in urban ZIP codes (81.5%) than rural ZIP codes (53.2%, P < 0.0001). Further research is needed to find out why vaccination rates were associated with incre...
Preventive Medicine, 2001
As part of a 3-year demonstration project to improve pneumococcal polysaccharide vaccine (PPV) co... more As part of a 3-year demonstration project to improve pneumococcal polysaccharide vaccine (PPV) coverage among older adults, the Minnesota Department of Health conducted a baseline evaluation of knowledge, attitudes, and beliefs among the general public regarding PPV. A random-digit dialing telephone survey was conducted among community-dwelling adults age 65 years or older in three metropolitan counties in Minnesota during April through June 1998. Three hundred fifty-three interviews were completed; self-reported PPV coverage was 59% (95% CI 54%, 64%). Nearly all (94%) respondents reported at least one medical visit in the past year. Unvaccinated respondents expressed willingness to be vaccinated if they knew about PPV&amp;amp;amp;amp;#39;s safety, dosage, and preventive role. In a final multivariate regression model, factors associated with PPV vaccination included awareness of PPV (OR 7.8; CI 2.1, 29.2; P = 0.002), opinion that receiving PPV is &amp;amp;amp;amp;quot;very important&amp;amp;amp;amp;quot; (OR 8.3; CI 3.2, 21.6; P &amp;amp;amp;amp;lt; 0.001), awareness that Medicare covers PPV (OR 5.1; CI 1.9, 13.8; P = 0.001), physician ever offering PPV (OR 21.7; CI 6.2, 76.6; P &amp;amp;amp;amp;lt; 0.001), and physician regularly offering PPV (OR 3.9; CI 1.1, 13.7; P = 0.03). Respondents were significantly influenced by their physician offering PPV. Therefore, providers&amp;amp;amp;amp;#39; practices are a critical target for improving PPV coverage. Educational efforts to inform patients about PPV and to address misconceptions (e.g., safety, efficacy, Medicare coverage) also may improve vaccination levels.
PEDIATRICS, 2005
Despite the dramatic pertussis decrease since the licensure of whole-cell pertussis (diphtheria-t... more 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; &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;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. To measure the pertussis vaccine effectiveness (VE) among US children 6 to 59 months of age. We conducted a case-control study in the Cincinnati, Ohio, metropolitan area, Colorado, Idaho, and Minnesota. 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. 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =2 nights per week, and cough illness of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =2-week duration among these household members in the month before the case patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s cough onset. Pertussis vaccine doses among case children were counted as valid if they were received &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =14 days before the cough onset date (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;valid period&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;). 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. 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or =13 months), compared with children who received dose 4 at an older age (age of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 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 (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =25 years of age), not living with an…
The Pediatric Infectious Disease Journal, 2004
... Bisgar d, DVM, MPH* F. Brian Pascual, MPH* Kristen R. Ehresmann, RN, MPH,f Claudia A. Miller,... more ... Bisgar d, DVM, MPH* F. Brian Pascual, MPH* Kristen R. Ehresmann, RN, MPH,f Claudia A. Miller, MS, f Christy Cianfrini, MPH, * Charles E. Jennings, BS,} Catherine A. Rebmann, MPH,§ Julie Gabel, DVM, MPH,§ Stephanie L. Schauer ... 4. Guris D, Strebel PM, Bardenheier В, et al ...
The Pediatric Infectious Disease Journal, 1998
A retrospective statewide immunization survey of the 69115 Minnesota children who entered kinderg... more A retrospective statewide immunization survey of the 69115 Minnesota children who entered kindergarten in 1992 was conducted. Information was collected from school immunization records on date of birth, dates of vaccination for each dose of vaccine, address of residence and race/ethnicity (when available). Immunization rates were assessed retrospectively for each month of a child&#39;s life from 2 to 48 months of age. Age-appropriate immunization was defined as receipt of all scheduled vaccines within 30 days of the recommended age. Immunization levels varied by vaccine, age of the child and race/ethnicity. For example at 19 months of age, 73% of students had received measles, mumps, rubella vaccine; however, only 39% had received their fourth dose of diphtheria, tetanus and pertussis vaccine. White, non-Hispanic students consistently had higher vaccination rates than children of other racial/ ethnic groups. For example 45% of white, non-Hispanic students were age-appropriately vaccinated at 16 months of age compared with 25% of Blacks, 30% of American Indians, 30% of white Hispanics and 28% of Asian-Pacific Islanders (Mantel-Haenzel chi square, P &lt; 0.001 for each comparison). Furthermore coverage rates frequently varied significantly by neighborhood, thereby identifying pockets of underimmunization within communities. Our data demonstrate that vaccination rates can vary substantially by age, race/ ethnicity and neighborhood. Detailed immunization assessment is necessary so that effective targeted interventions can be developed.
Journal of Public Health Management and Practice, 2009
The Minnesota Department of Health (MDH) examined hospital practices as recommended by the Adviso... more The Minnesota Department of Health (MDH) examined hospital practices as recommended by the Advisory Committee on Immunization Practice in 2005 that hepatitis B vaccine should be administered universally to newborn infants prior to hospital discharge and within 12 hours of birth if their mothers test positive or are admitted with unknown status for hepatitis B surface antigen. The MDH conducted a survey of perinatal hepatitis B birth dosing policies in Minnesota birthing hospitals, which prompted (1) and investigation of hospital birth dose rates from the Immunization Information System (IIS) and (2) a chart review of three selected hospitals with low rates. The (IIS) records of children born in Minnesota during 2007 and the first 5 months of 2008 showed a hepatitis B birth dose rate that was lower than expected (2007: 37%; 2008: 48%). The chart review of three hospitals with low birth does rates showed rates for the first 6 months of 2008 of 94%, 89%, and 91% compared with IIS rates of 1.4%, 40%, and 39% respectively, during the same time period. These results prompted MDH to increase efforts to provide education to birth registrars on the importance of hepatitis B vaccine data on the birth certificate and to promote regular transmission of hospital vaccination data to the IIS.
Journal of Public Health Management and Practice, 2006
Ehresmann r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r... more Ehresmann r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r W hen Chiron announced its inability to provide influenza vaccine during the 2004-05 season, state and local public health agencies in Minnesota immediately took action to assess and redistribute existing influenza vaccine supplies to those at the highest risk. This experience in 2004, coupled with product delivery delays and shortages in other years, prompted development of a Web-based tool to inventory influenza vaccine orders prior to the start of the 2005-06 influenza season. The resulting data were summarized by region of the state, and the proportion of coverage for the priority risk group population was computed. Based on the importance of having order information available, this vaccine inventory tool will be continually refined and utilized in preparation for each upcoming influenza season.
Journal of Infectious Diseases, 1995
An outbreak of measles occurred in conjunction with the International Special Olympics Games in t... more An outbreak of measles occurred in conjunction with the International Special Olympics Games in the Minneapolis-St. Paul metropolitan area during July 1991. Sixteen outbreak-associated cases of measles were reported among US residents from seven states, with 9 additional cases resulting from subsequent transmission. The primary case was a track and field athlete from Argentina. Transmission occurred in three settings: the opening ceremonies in a domed stadium, track and field events, and first aid stations. Eight secondary cases had their only potential exposure at the opening ceremonies; 2 of these cases were unrelated spectators sitting in the same section of the upper deck &gt; 30.5 m above the athlete&#39;s entrance. These findings demonstrate that the risk of indigenous measles transmission associated with international events in the United States must be considered, even in areas without recent measles activity. Moreover, the dynamic airborne transmission of measles illustrates the potential for transmission in the absence of a recognized exposure.
Journal of Clinical Microbiology, 2003
Erythromycin treatment failures and in vitro resistance of Bordetella pertussis have been reporte... more Erythromycin treatment failures and in vitro resistance of Bordetella pertussis have been reported on several occasions in the past few years, but the mechanism of resistance has not been described. One potential mechanism, genetic modification of the erythromycin-binding site on the 23S rRNA of the 50S ribosomal subunit, has been observed in other bacteria. To explore this possibility, we amplified the portion of the 23S rRNA gene encoding the central loop of domain V. DNA sequencing and restriction fragment length polymorphism of the PCR products showed that each of the four erythromycin-resistant B. pertussis strains tested contained an A-to-G transition mutation at position 2058 (Escherichia coli numbering) of the 23S rRNA gene. The mutation was not found in seven erythromycin-susceptible isolates tested. Two of the resistant isolates were heterozygous, containing at least one mutant copy and one wild-type copy of the 23S rRNA gene. These results indicate that erythromycin resistance in these strains is likely due to a mutation of the erythromycinbinding site in the 23S rRNA gene. Identification of the resistance mechanism will facilitate development of molecular susceptibility testing methods that can be used directly on clinical specimens in the absence of an isolate.
Clinical Infectious Diseases, 2008
We present 2 case reports in the United States and investigations of diphtheria-like illness caus... more 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. Both case patients and close human and animal contacts were investigated by their respective state health departments. 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. 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.
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Papers by Kristen Ehresmann