Impact of Public Health Responses During a Measles Outbreak in an Amish Community in Ohio: Modeling the Dynamics of Transmission.

We quantified measles transmissibility during a measles outbreak in Ohio in 2014 to evaluate the impact of public health responses. Case incidence and the serial interval (time between symptom onset in primary cases and secondary cases) were used to assess trends in the effective reproduction number R (the average number of secondary cases generated per case). A mathematical model was parameterized using early R values to determine the size and duration of the outbreak that would have occurred if containment measures had not been initiated, as well as the impact of vaccination. As containment started, we found a 4-fold decline in R (from approximately 4 to 1) over the course of 2 weeks and maintenance of R < 1 as control measures continued. Under a conservative scenario, the model estimated 8,472 cases (90% confidence interval (CI): 8,447, 8,489) over 195 days (90% CI: 179, 223) without control efforts and 715 cases (90% CI: 103, 1,338) over 128 days (90% CI: 117, 139) when vaccination was included; 7,757 fewer cases (90% CI: 7,130, 8,365) and 67 fewer outbreak days (90% CI: 48, 98) were attributed to vaccination. Vaccination may not account entirely for transmission reductions, suggesting that changes in community behavior (social distancing) and other control efforts (isolation, quarantining) are important. Our findings highlight the benefits of measles outbreak response and of understanding behavior change dynamics.

Influenza Vaccination Modifies Disease Severity Among Community-dwelling Adults Hospitalized With Influenza.

Background: We investigated the effect of influenza vaccination on disease severity in adults hospitalized with laboratory-confirmed influenza during 2013-14, a season in which vaccine viruses were antigenically similar to those circulating. Methods: We analyzed data from the 2013-14 influenza season and used propensity score matching to account for the probability of vaccination within age strata (18-49, 50-64, and ≥65 years). Death, intensive care unit (ICU) admission, and hospital and ICU lengths of stay (LOS) were outcome measures for severity. Multivariable logistic regression and competing risk models were used to compare disease severity between vaccinated and unvaccinated patients, adjusting for timing of antiviral treatment and time from illness onset to hospitalization. Results: Influenza vaccination was associated with a reduction in the odds of in-hospital death among patients aged 18-49 years (adjusted odds ratios [aOR] = 0.21; 95% confidence interval [CI], 0.05 to 0.97), 50-64 years (aOR = 0.48; 95% CI, 0.24 to 0.97), and ≥65 years (aOR = 0.39; 95% CI, 0.17 to 0.66). Vaccination also reduced ICU admission among patients aged 18-49 years (aOR = 0.63; 95% CI, 0.42 to 0.93) and ≥65 years (aOR = 0.63; 95% CI, 0.48 to 0.81), and shortened ICU LOS among those 50-64 years (adjusted relative hazards [aRH] = 1.36; 95% CI, 1.06 to 1.74) and ≥65 years (aRH = 1.34; 95% CI, 1.06 to 1.73), and hospital LOS among 50-64 years (aRH = 1.13; 95% CI, 1.02 to 1.26) and ≥65 years (aRH = 1.24; 95% CI, 1.13 to 1.37). Conclusions: Influenza vaccination during 2013-14 influenza season attenuated adverse outcome among adults that were hospitalized with laboratory-confirmed influenza.

Outbreak of Influenza A(H3N2) Variant Virus Infections Among Persons Attending Agricultural Fairs Housing Infected Swine - Michigan and Ohio, July-August 2016.

On August 3, 2016, the Ohio Department of Health Laboratory reported to CDC that a respiratory specimen collected on July 28 from a male aged 13 years who attended an agricultural fair in Ohio during July 22-29, 2016, and subsequently developed a respiratory illness, tested positive by real-time reverse transcription-polymerase chain reaction (rRT-PCR) for influenza A(H3N2) variant* (H3N2v). The respiratory specimen was collected as part of routine influenza surveillance activities. The next day, CDC was notified of a child aged 9 years who was a swine exhibitor at an agricultural fair in Michigan who became ill on July 29, 2016, and tested positive for H3N2v virus at the Michigan Department of Health and Human Services Laboratory. Investigations by Michigan and Ohio health authorities identified 18 human infections linked to swine exhibits at agricultural fairs. To minimize transmission of influenza viruses from infected swine to visitors, agricultural fair organizers should consider prevention measures such as shortening the time swine are on the fairgrounds, isolating ill swine, maintaining a veterinarian on call, providing handwashing stations, and prohibiting food and beverages in animal barns. Persons at high risk for influenza-associated complications should be discouraged from entering swine barns.

A Measles Outbreak in an Underimmunized Amish Community in Ohio.

BACKGROUND: Although measles was eliminated in the United States in 2000, importations of the virus continue to cause outbreaks. We describe the epidemiologic features of an outbreak of measles that originated from two unvaccinated Amish men in whom measles was incubating at the time of their return to the United States from the Philippines and explore the effect of public health responses on limiting the spread of measles. METHODS: We performed descriptive analyses of data on demographic characteristics, clinical and laboratory evaluations, and vaccination coverage. RESULTS: From March 24, 2014, through July 23, 2014, a total of 383 outbreak-related cases of measles were reported in nine counties in Ohio. The median age of case patients was 15 years (range, <1 to 53); a total of 178 of the case patients (46%) were female, and 340 (89%) were unvaccinated. Transmission took place primarily within households (68% of cases). The virus strain was genotype D9, which was circulating in the Philippines at the time of the reporting period. Measles-mumps-rubella (MMR) vaccination coverage with at least a single dose was estimated to be 14% in affected Amish households and more than 88% in the general (non-Amish) Ohio community. Containment efforts included isolation of case patients, quarantine of susceptible persons, and administration of the MMR vaccine to more than 10,000 persons. The spread of measles was limited almost exclusively to the Amish community (accounting for 99% of case patients) and affected only approximately 1% of the estimated 32,630 Amish persons in the settlement. CONCLUSIONS: The key epidemiologic features of a measles outbreak in the Amish community in Ohio were transmission primarily within households, the small proportion of Amish people affected, and the large number of people in the Amish community who sought vaccination. As a result of targeted containment efforts, and high baseline coverage in the general community, there was limited spread beyond the Amish community. (Funded by the Ohio Department of Health and the Centers for Disease Control and Prevention.).

Spontaneous abortion among pregnancies conceived using assisted reproductive technology in the United States.

OBJECTIVE: To examine rates and risk factors for spontaneous abortion among pregnancies conceived using assisted reproductive technology (ART). METHODS: Subjects were 62,228 clinical pregnancies resulting from ART procedures initiated in 1996-1998 in US clinics. Spontaneous abortion was based on ART clinic report and was defined as loss of the entire pregnancy. Spontaneous abortion rates for ART pregnancies were compared with spontaneous abortion rates from the National Survey of Family Growth, a population-based survey of US women 15-44 years. RESULTS: The spontaneous abortion rate among ART pregnancies was 14.7%. This was similar to rates among pregnancies reported in the National Survey of Family Growth. Among pregnancies conceived with the patient's oocytes and freshly fertilized embryos, the spontaneous abortion risk ranged from 10.1% among women 20-29 years to 39.3% among women older than 43. Spontaneous abortion risk among pregnancies conceived with donor eggs was 13.1% with little variation by patient age. Spontaneous abortion risk was increased for pregnancies conceived with frozen and thawed embryos and decreased among multiple-gestation pregnancies. Spontaneous abortion risk was increased among women reporting previous spontaneous abortions and ART attempts, and among women who used clomiphene or zygote intrafallopian transfer. Pregnancies conceived by young women, but gestated by a surrogate, were at increased risk for spontaneous abortion in comparison with young women who gestated their own pregnancies. CONCLUSION: These findings suggest that ART does not pose a risk for spontaneous abortion. Factors related to oocyte or embryo quality are of primary importance in assessing spontaneous abortion risk.

Population exposures to I-131 releases from Hanford Nuclear Reservation and preterm birth, infant mortality, and fetal deaths.

Communities surrounding the Hanford Nuclear Reservation in southeastern Washington were exposed to radionuclides, particularly iodine-131, released during the period 1945 to 1951. This study evaluated whether estimated iodine-131 exposures were risk factors for infant mortality, fetal death, and preterm birth in the years of highest releases, 1945 and 1946. Data on births, fetal deaths, and infant deaths, during the period 1940 to 1950, were abstracted from vital records for an eight county area surrounding the Hanford facility. The analysis included 56,320 births, 1,656 infant deaths, and 806 fetal deaths. The Hanford Environmental Dose Reconstruction project provided iodine-131 dose estimates for the 1,102 grid areas in the study area. The grid areas were collapsed into 4 exposure groups using estimated exposure to iodine-131 during 1945. Each birth and death record was assigned to one of the four grid groups based on mother's residence at the time of birth. Comparisons of preterm birth, infant death, and fetal death rates were made among the grid groupings for the primary exposure period (1945 to 1946) and for other years of the study period (i.e., 1940 to 1944 and 1947 to 1950). In the grid group with the highest estimated iodine-131 exposures, the mother's residence during the latter part of pregnancy was associated with preterm birth (OR = 1.74, 95% CI = 1.09-2.72). An association with infant mortality (OR = 1.26, 95% CI = 0.79-1.97) was suggested. No association was found for fetal deaths. This study found that iodine-131 exposure was associated with increased risk of preterm birth. This finding is biologically plausible because other studies have found that: (1) iodine-131 exposure can cause hypothyroidism, and (2) overt or subclinical hypothyroidism during pregnancy can increase a mother's risk of a preterm delivery.