Background
Variant influenza virus infections are rare but may have pandemic potential if person-to-person transmission is efficient. We describe the epidemiology of a multistate outbreak of an influenza A(H3N2) variant virus (H3N2v) first identified in 2011.
Methods
We identified laboratory-confirmed cases of H3N2v and used a standard case report form to characterize illness and exposures. We considered illness to result from person-to-person H3N2v transmission if swine contact was not identified within 4 days prior to illness onset.
Results
From 9 July to 7 September 2012, we identified 306 cases of H3N2v in 10 states. The median age of all patients was 7 years. Commonly reported signs and symptoms included fever (98%), cough (85%), and fatigue (83%). Sixteen patients (5.2%) were hospitalized, and 1 fatal case was identified. The majority of those infected reported agricultural fair attendance (93%) and/or contact with swine (95%) prior to illness. We identified 15 cases of possible person-to-person transmission of H3N2v. Viruses recovered from patients were 93%–100% identical and similar to viruses recovered from previous cases of H3N2v. All H3N2v viruses examined were susceptible to oseltamivir and zanamivir and resistant to adamantane antiviral medications.
Conclusions
In a large outbreak of variant influenza, the majority of infected persons reported exposures, suggesting that swine contact at an agricultural fair was a risk for H3N2v infection. We identified limited person-to-person H3N2v virus transmission, but found no evidence of efficient or sustained person-to-person transmission. Fair managers and attendees should be aware of the risk of swine-to-human transmission of influenza viruses in these settings.
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.).
We report the first documented mixed outbreak of B. pertussis and B. holmesii infections. Bordetella holmesii particularly affected adolescents. Although laboratory capacity limitations might inhibit routine use of multitarget PCR for clinical diagnosis, focused testing and enhanced surveillance might improve understanding the burden of B. holmesii infection.
SCHERICHIA COLI O157, SUCH AS E coli O157:H7, causes approximately 70000 illnesses and 60 deaths annually in the United States. 1 Illness is often characterized by severe bloody diarrhea; renal failure from hemolytic-uremic syndrome (HUS) may occur in 3% to 7% of cases. 2 Healthy cattle are believed to be the most important reservoir of E coli O157. 2 Humans usually become infected from contaminated food or water or from contact with infected animals, infected humans, or either's excreta. 3,4 Because E coli O157 has a low infectious dose and can survive in the environment, environmental contamination with E coli O157 may be an important public health problem. 5,6 Outbreaks have been linked to contamination of surfaces regularly touched by animals, such as the soil of pastures or railings in petting zoos. 7-9 County fairs are popular throughout the United States. 10 Because fairs bring animals and humans into close contact, they are increasingly recognized as a setting for E coli O157 outbreaks. 11 Such outbreaks often affect multiple communities because fairs attract large numbers of individuals, particularly children, and person-toperson transmission may occur after a fair has ended. We describe an investigation of a fair-associated E coli O157 outbreak in which epidemiological and microbiological studies document that infections can be Author Affiliations are listed at the end of this article.
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