Sara Robinson

Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus Infections, United States, 2010–11

During October 2010–July 2011, 1.0% of pandemic (H1N1) 2009 viruses in the United States were oseltamivir resistant, compared with 0.5% during the 2009–10 influenza season. Of resistant viruses from 2010–11 and 2009–10, 26% and 89%, respectively, were from persons exposed to oseltamivir before specimen collection. Findings suggest limited community transmission of oseltamivir-resistant virus.

Eastern Equine Encephalitis: An Emerging Arboviral Disease Threat, Maine, 2009

BACKGROUND Eastern equine encephalitis (EEE) is one of the most severe arboviral encephalitides in North America. Before 2009, limited nonhuman EEE virus activity had been reported in Maine, all from the southernmost area of the state. No human case has been reported in a Maine resident. METHODS We review all EEE virus activity reported to Maine Centers for Disease Control in 2009 and describe current testing practices for possible human EEE cases. RESULTS In 2009, fatal cases of EEE were identified in 15 horses, 1 llama, and 3 flocks of pheasants in Maine, with activity extending into the central part of the state. Although no human EEE cases were identified, diagnostic testing practices of most meningitis and encephalitis cases were inadequate to exclude EEE. CONCLUSIONS Work to better define the expanding range of EEE virus in Maine is warranted, along with education of healthcare providers regarding appropriate testing for this serious disease.

An epizootic of eastern equine encephalitis virus, Maine, USA in 2009: outbreak description and entomological studies.

From July to September, 2009, an outbreak of eastern equine encephalitis virus (EEEv) occurred in five counties in Maine. The virus was isolated from 15 horses, 1 llama, and pheasants in three separate captive flocks. One wild turkey, screened before translocation, also showed exposure to the virus in January 2010. Two pools of Culiseta melanura (Coquillett) tested positive for EEEv during routine seasonal surveillance in York County in September, but none of the mosquitoes collected during rapid response surveys tested positive. There were more Cs. melanura in July, August, and September 2009 than in preceding (2006-08) and subsequent (2010-11) years. August and September Cs. melanura abundances were correlated with July rainfall, and abundance of all species combined was correlated with total rainfall for the meteorological summer. This outbreak represents a substantial expansion of the range of EEEv activity in northern New England.

Effects of immunizing school children with 2009 influenza A (H1N1) monovalent vaccine on absenteeism among students and teachers in Maine

The overall and indirect effects of immunizing school children with influenza A (H1N1) 2009 pandemic virus vaccine prior to and during the peak of virus circulation were evaluated on student and teacher school absenteeism. We used records collected from late 2009 through early 2010 from schools in four Maine counties. Mixed logistic regression models were used to estimate the daily association between school-level immunization coverage and absenteeism by level of influenza activity, after adjusting for the proportion of students receiving reduced-cost lunches, student minority status, absences adjacent to weekends and Thanksgiving, rural school location, and the circulation of other respiratory viruses. Increasing student immunization coverage was associated with reduced absenteeism during periods of high influenza activity. For example, as immunization coverage during the peak week of pandemic virus circulation increased from 38% to 69% (the 10th and 90th percentiles of observed coverage, respectively), relative reductions in daily absenteeism among all students, unimmunized students, and teachers were 8.2% (95% confidence interval [CI]: 6.5, 9.9), 5.7% (95% CI: 4.2, 7.3), and 8.7% (95% CI: 1.3, 16), respectively. Increased vaccination coverage among school-aged Maine children had modest overall and indirect effects on student and teacher absenteeism, despite vaccination occurring just prior and during peak pandemic virus circulation.

Using Wild White-Tailed Deer to Detect Eastern Equine Encephalitis Virus Activity in Maine

Serum from 226 free-ranging white-tailed deer (Odocoileus virginianus) was screened for Eastern Equine Encephalitis Virus (EEEV) antibodies using plaque reduction neutralization tests. EEEV antibodies were detected in 7.1% of samples. This is the first time EEEV antibodies have been detected in O. virginianus populations in the state of Maine (ME). The highest percentage of EEEV positive sera was in Somerset County (19%) in central ME, and this is the first time that EEEV activity has been detected in that County. EEEV RNA was not detected in any of the 150 harvested deer brain samples submitted to the ME Department of Inland Fisheries and Wildlife as a part of screening for Chronic Wasting Disease. This suggests that screening deer brains is not an efficient method to detect EEEV activity. For each serum sample tested, the geographic location in which the deer was harvested was recorded. Significant spatial clustering of antibody-positive sera samples was not detected. Relative to seronegative deer, seropositive deer were slightly more likely to be harvested in nonforested areas compared with forested areas. Results indicate that screening of free-ranging deer sera can be a useful tool for detecting EEEV activity in ME and other parts of North America.

Lyme Disease in Maine: a Comparison of NEDSS Surveillance Data and Maine Health Data Organization Hospital Discharge data.

Background Lyme disease is the most commonly reported vector borne disease in the United States and is a major public health concern in Maine. Maine Center for Disease Control and Prevention (Maine CDC) monitors Lyme disease through a passive surveillance system. In order to validate the Lyme disease surveillance system, Maine CDC was interested in comparing trends with a secondary data source. Specifically, Maine CDC was interested in comparing trends by age group, gender, geography, and timelines. Also, because hospitalization due to Lyme disease is rare, this analysis provided an opportunity to look at the diagnosis codes used for Lyme disease visits. The purpose of this paper is to compare the data acquired through surveillance to a secondary data source in order to evaluate the completeness of the data and verify trends. Methods Surveillance data was extracted from Maine’s NEDSS Base System for the years 2008 – 2011. Only confirmed and probable cases were included in data analysis. The Maine Health Data Organization (MHDO) collects information on all hospital inpatient and outpatient data visits and was used for this comparison. MHDO inpatient and outpatient hospital encounters with a diagnosis of 08881 in any diagnosis field were extracted from the full dataset from 2008 – 2011. Results Surveillance data showed the 5-14 year old age group had the highest rates of Lyme disease while outpatient data showed adults over the age of 45 to have the highest rates. Outpatient data showed a higher percentage of females with Lyme disease visits. Geographic trends did not match well between surveillance data and MHDO data which may be due to the hospital being used as proxy for the patient address. Timeliness trends were consistent between all sources, with the majority of Lyme disease occurring in the summer months of June, July and August. The majority of outpatient visits had Lyme disease listed as their primary diagnosis while the majority of inpatient visits had Lyme disease as a secondary or lower diagnosis. Conclusions There were several limitations to this study including incomplete data, and the inability to differentiate between new and old Lyme diagnoses. There is reasonably good similarity in the trends of these two systems helping validate the usefulness of Maine’s Lyme disease surveillance system. Many of the discrepancies warrant further investigation, and may lead to future opportunities for education or improvement in Lyme disease surveillance.

Varicella Outbreak Surveillance in Schools in Sentinel Jurisdictions, 2012–2015

BACKGROUND In 2007, a routine second dose of varicella vaccine was recommended in the United States for children aged 4 to 6 years to better control varicella-zoster virus circulation and outbreaks. Sentinel varicella outbreak surveillance was established to assess feasibility of surveillance and describe outbreaks that are occurring. METHODS Through the Centers for Disease Control and Prevention Epidemiology Laboratory Capacity funding, health departments conducted active surveillance for varicella outbreaks in schools from 2012 to 2015. Outbreaks of varicella were defined as ≥5 cases in a school within at least 1 incubation period (21 days). School nurses, healthcare providers, or laboratories reported cases and outbreaks of varicella to health departments; demographic, vaccination, and clinical data were collected. RESULTS Georgia, Houston, Maine, Minnesota, New York City, and Philadelphia participated in all 3 years; Puerto Rico and West Virginia participated in 2012 to 2013; and Kansas and Arkansas participated in 2014 to 2015. Twenty-nine outbreaks including 262 cases were reported. The median size of the outbreaks was 7 cases (range, 5-31 cases), and the median duration was 31 days (range, 4-100 days). Of the case-patients associated with larger outbreaks (≥8 cases), 55.4% were unvaccinated, and 15.7% and 18.1% had received 1 or 2 doses of vaccine, respectively. In small outbreaks (5-7 cases), 33.3% of case-patients were unvaccinated, and 16.7% and 38.5% had received 1 or 2 doses of vaccine, respectively. CONCLUSIONS The majority of cases associated with outbreaks occurred in undervaccinated children (unvaccinated and 1-dose vaccine recipients). Outbreaks with a greater proportion of 2-dose vaccine recipients were smaller. Varicella outbreak surveillance is feasible, and continued monitoring of outbreaks remains important for describing the epidemiology of varicella during the 2-dose varicella vaccination program.

Non-mumps Viral Parotitis During the 2014–2015 Influenza Season in the United States

Background During the 2014-2015 US influenza season, 320 cases of non-mumps parotitis (NMP) among residents of 21 states were reported to the Centers for Disease Control and Prevention (CDC). We conducted an epidemiologic and laboratory investigation to determine viral etiologies and clinical features of NMP during this unusually large occurrence. Methods NMP was defined as acute parotitis or other salivary gland swelling of >2 days duration in a person with a mumps- negative laboratory result. Using a standardized questionnaire, we collected demographic and clinical information. Buccal samples were tested at the CDC for selected viruses, including mumps, influenza, human parainfluenza viruses (HPIVs) 1-4, adenoviruses, cytomegalovirus, Epstein-Barr virus (EBV), herpes simplex viruses (HSVs) 1 and 2, and human herpes viruses (HHVs) 6A and 6B. Results Among the 320 patients, 65% were male, median age was 14.5 years (range, 0-90), and 67% reported unilateral parotitis. Commonly reported symptoms included sore throat (55%) and fever (48%). Viruses were detected in 210 (71%) of 294 NMP patients with adequate samples for testing, ≥2 viruses were detected in 37 samples, and 248 total virus detections were made among all samples. These included 156 influenza A(H3N2), 42 HHV6B, 32 EBV, 8 HPIV2, 2 HPIV3, 3 adenovirus, 4 HSV-1, and 1 HSV-2. Influenza A(H3N2), HHV6B, and EBV were the most frequently codetected viruses. Conclusions Our findings suggest that, in addition to mumps, clinicians should consider respiratory viral (influenza) and herpes viral etiologies for parotitis, particularly among patients without epidemiologic links to mumps cases or outbreaks.

Influenza-Associated Parotitis During the 2014–2015 Influenza Season in the United States

Background During the 2014-2015 influenza season in the United States, 256 cases of influenza-associated parotitis were reported from 27 states. We conducted a case-control study and laboratory investigation to further describe this rare clinical manifestation of influenza. Methods During February 2015-April 2015, we interviewed 50 cases (with parotitis) and 124 ill controls (without parotitis) with laboratory-confirmed influenza; participants resided in 11 states and were matched by age, state, hospital admission status, and specimen collection date. Influenza viruses were characterized using real-time polymerase chain reaction and next-generation sequencing. We compared cases and controls using conditional logistic regression. Specimens from additional reported cases were also analyzed. Results Cases, 73% of whom were aged <20 years, experienced painful (86%), unilateral (68%) parotitis a median of 4 (range, 0-16) days after onset of systemic or respiratory symptoms. Cases were more likely than controls to be male (76% vs 51%; P = .005). We detected influenza A(H3N2) viruses, genetic group 3C.2a, in 100% (32/32) of case and 92% (105/108) of control specimens sequenced (P = .22). Influenza B and A(H3N2) 3C.3 and 3C.3b genetic group virus infections were detected in specimens from additional cases. Conclusions Influenza-associated parotitis, as reported here and in prior sporadic case reports, seems to occur primarily with influenza A(H3N2) virus infection. Because of the different clinical and infection control considerations for mumps and influenza virus infections, we recommend clinicians consider influenza in the differential diagnoses among patients with acute parotitis during the influenza season.

Update on the Distribution of Aedes japonicus in Maine, 2001–15

Abstract The first confirmed collection of Aedes japonicus in Maine was in Cumberland County in 2001. Since that initial collection, it has been found in 7 of Maines 16 counties between 2001 and 2015. These collections include the northernmost collection of Ae. japonicus in the eastern USA, from Madawaska in Aroostook County. Though mosquito surveillance is limited in the state, it is evident that Ae. japonicus is more widely distributed in Maine than previously believed although its role in arboviral transmission in the region is unknown.