Mumps vaccine effectiveness of a 3rd dose of measles, mumps, rubella vaccine in school settings during a mumps outbreak -- Arkansas, 2016-2017.

Objectives: The largest mumps outbreak in the United States since 2006 occurred in Arkansas during the 2016-17 school year. An additional dose (third dose) of measles-mumps-rubella vaccine (MMR3) was offered to school children. We evaluated the vaccine effectiveness (VE) of MMR3 compared with two doses of MMR for preventing mumps among school-aged children during the outbreak. Study design: A generalized linear mixed effects model was used to estimate the incremental vaccine effectiveness (VE) of a third dose of MMR compared with two doses of MMR for preventing mumps. Methods: We obtained school enrollment, immunization status and mumps case status from school registries, Arkansas's immunization registry, and Arkansas's mumps surveillance system, respectively. We included students who previously received 2 doses of MMR in schools with ≥1 mumps case after the MMR3 clinic. We used a generalized linear mixed model to estimate VE of MMR3 compared with two doses of MMR. Results: Sixteen schools with 9272 students were included in the analysis. Incremental VE of MMR3 versus a two-dose MMR regimen was 52.7% (95% confidence interval [CI]: -3.6%‒78.4%) overall and in 8 schools with high mumps transmission it was 64.0% (95% CI: 1.2%‒86.9%). MMR3 VE was higher among middle compared with elementary school students (68.5% [95% CI: -30.2%‒92.4%] vs 37.6% [95% CI: -62.5%‒76.1%]); these differences were not statistically significant. Conclusion: Our findings suggest MMR3 provided additional protection from mumps compared with two MMR doses in elementary and middle school settings during a mumps outbreak.

Potential Association of Legionnaires' Disease with Hot Spring Water, Hot Springs National Park and Hot Springs, Arkansas, USA, 2018-2019.

Legionella pneumophila is the cause of Legionnaires' disease, a life-threatening pneumonia that occurs after inhalation of aerosolized water containing the bacteria. Legionella growth occurs in stagnant, warm-to-hot water (77°F-113°F) that is inadequately disinfected. Piped hot spring water in Hot Springs National Park, Arkansas, USA, has naturally high temperatures (>135°F) that prevent Legionella growth, and Legionnaires' disease has not previously been associated with the park or other hot springs in the United States. During 2018-2019, Legionnaires' disease occurred in 5 persons after they visited the park; 3 of these persons were potentially exposed in spa facilities that used untreated hot spring water. Environmental testing revealed Legionella bacteria in piped spring water, including 134°F stagnant pipe water. These findings underscore the importance of water management programs to reduce Legionella growth in plumbing through control activities such as maintaining hot water temperatures, reducing stored water age, and ensuring adequate water flow.

Mumps in a highly vaccinated Marshallese community in Arkansas, USA: an outbreak report.

BACKGROUND: During 2000-15, Arkansas Department of Health, Little Rock, AR, USA, investigated between one and six cases of mumps each year. From Aug 5, 2016, to Aug 5, 2017, the department received notification of more than 4000 suspected mumps cases in the second largest outbreak in the USA in the past 30 years. METHODS: Arkansas Department of Health investigated all reported cases of mumps to ascertain exposure, travel, and vaccination histories and identify close contacts. Cases were classified as confirmed if the patient had laboratory confirmation of mumps virus or probable if they had clinical symptoms and either a positive serological test or a known epidemiological link to a confirmed case. FINDINGS: 2954 cases of mumps related to the outbreak were identified during the outbreak period: 1665 (56%) were laboratory confirmed, 1676 (57%) were in children aged 5-17 years, and 1692 (57%) were in Marshallese people. Among the 1676 school-aged cases, 1536 (92%) had previously received at least two doses of a vaccine containing the mumps virus. Although 19 cases of orchitis were reported, severe complications were not identified. Unusual occurrences, such as recurrent parotitis and prolonged viral shedding, were observed mostly in Marshallese individuals. Viral samples were characterised as genotype G. INTERPRETATION: This large-scale outbreak, primarily affecting a marginalised community with intense household crowding, highlights the need for coordinated, interdisciplinary, and non-traditional outbreak responses. This outbreak raises questions about mumps vaccine effectiveness and potential waning immunity. FUNDING: Council of State and Territorial Epidemiologists and US Centers for Disease Control and Prevention.

Burkholderia thailandensis Isolated from Infected Wound, Arkansas, USA.

The bacterium Burkholderia thailandensis, a member of the Burkholderia pseudomallei complex, is generally considered nonpathogenic; however, on rare occasions, B. thailandensis infections have been reported. We describe a clinical isolate of B. thailandensis, BtAR2017, recovered from a patient with an infected wound in Arkansas, USA, in 2017.

Variation in Tularemia Clinical Manifestations-Arkansas, 2009-2013.

BACKGROUND: Francisella tularensis, although naturally occurring in Arkansas, is also a Tier 1 select agent and potential bioterrorism threat. As such, tularemia is nationally notifiable and mandatorily reported to the Arkansas Department of Health. We examined demographic and clinical characteristics among reported cases and outcomes to improve understanding of the epidemiology of tularemia in Arkansas. METHODS: Surveillance records on all tularemia cases investigated during 2009-2013 were reviewed. RESULTS: The analytic dataset was assembled from 284 tularemia reports, yielding 138 probable and confirmed tularemia cases during 2009-2013. Arthropod bite was identified in 77% of cases. Of 7 recognized tularemia manifestations, the typhoidal form was reported in 47% of cases, approximately double the proportion of the more classic manifestation, lymphadenopathy. Overall, 41% of patients were hospitalized; 3% died. The typhoidal form appeared to be more severe, accounting for the majority of sepsis and meningitis cases, hospitalizations, and deaths. Among patients with available antibiotic data, 88% received doxycycline and 12% received gentamicin. CONCLUSIONS: Contrary to expectation, lymphadenopathy was not the most common manifestation observed in our registry. Instead, our patients were more likely to report only generalized typhoidal symptoms. Using lymphadenopathy as a primary symptom to initiate tularemia testing may be an insensitive diagnostic strategy and result in unrecognized cases. In endemic areas such as Arkansas, suspicion of tularemia should be high, especially during tick season. Outreach to clinicians describing the full range of presenting symptoms may help address misperceptions about tularemia.

Possible Transfusion-Transmitted Babesia divergens-like/MO-1 Infection in an Arkansas Patient.

A patient with asplenia and multiple red blood cell transfusions acquired babesiosis infection with Babesia divergens-like/MO-1 organisms and not Babesia microti, the common United States species. He had no known tick exposure. This is believed to be the first transfusion-transmitted case and the fifth documented case of B. divergens-like/MO-1 infection.

Notes from the Field: Cluster of Tuberculosis Cases Among Marshallese Persons Residing in Arkansas - 2014-2015.

During early September 2014, the Arkansas Department of Health identified an increased number of tuberculosis (TB) cases among a unique population in a well-circumscribed geographical area in northwest Arkansas. The Compact of Free Association Act of 1985 (Public Law 99-239, amended in 2003 by Public Law 108-188) established the Republic of the Marshall Islands (RMI) as an independent nation, and persons from the RMI can travel freely (with valid RMI passport) to and from the United States as nonimmigrants without visas (1). Marshallese started settling in northwest Arkansas during the early 1990s because of employment and educational opportunities (2). According to the 2010 Census, an estimated 4,300 Marshallese resided in Arkansas (2), mostly within one county which ranked 6th in the United States for counties with the highest percentage of Native Hawaiians and Other Pacific Islanders (3). It is estimated that this number has been growing steadily each year since the 2010 Census; however, obtaining an accurate count is difficult. The RMI is a TB high-incidence country, with a case-rate of 212.7 per 100,000 persons for 2014, whereas the case-rate was 3.1 per 100,000 persons in Arkansas and 2.9 per 100,000 persons in the United States (4,5). Screening for either active TB or latent TB infection (LTBI) is not required for Marshallese entry to the United States (1).

Association of School-Based Influenza Vaccination Clinics and School Absenteeism--Arkansas, 2012-2013.

BACKGROUND: Influenza is a major cause of seasonal viral respiratory illness among school-aged children. Accordingly, the Arkansas Department of Health (ADH) coordinates >800 school-based influenza immunization clinics before each influenza season. We quantified the relationship between student influenza vaccination in Arkansas public schools and school absenteeism during the 2012-2013 influenza season. METHODS: The relationship between the percent of students vaccinated in Arkansas public schools during ADH-facilitated clinics and the average daily percent of students absent from school during the 2012-2013 influenza season was quantified using linear regression modeling. The effect of increasing vaccination coverage among students on absentee days in the Arkansas public school system was estimated. RESULTS: For every 1% higher vaccination coverage, 0.027% fewer absenteeism days were predicted. Larger school size was associated with higher absenteeism and predicted decreases in absenteeism were larger in magnitude for larger schools compared with smaller schools. Extrapolation of the model showed that a 10% higher vaccination level was associated with a reduction of 16-163 student absentee days per school over a 12-week influenza season. CONCLUSIONS: Influenza vaccination is an effective tool to reduce school absenteeism. School-based clinics are a feasible way to target influenza vaccinations to school-aged children.

Hepatitis C in Arkansas: updates on epidemiology, testing and treatment.

Hepatitis C infection is the most common blood-borne infection in the United States with an estimated 2.7 million individuals suffering from chronic infection. Of those who are infected with Hepatitis C virus, 75-85% develop chronic infection. Without treatment for chronic infection, individuals can develop liver diseases, such as cirrhosis and hepatocellular carcinoma, during many years of asymptomatic infection. To examine the burden of Hepatitis C virus infection in the state, the Arkansas Department of Health created an epidemiologic profile based on data collected in 2013 from several data sources, including the department's Hepatitis C surveillance program. In order to make more Arkansans aware of their infection, the local health units in all 75 counties of the state recently began screening individuals at risk for the disease, including persons born during the years 1945-1965. Despite recent advances in treatment efficacy, identifying infected individuals and connecting patients to affordable HCV treatment and care remain priorities.

Histoplasmosis associated with a bamboo bonfire--Arkansas, October 2011.

On October 27, 2011, the Arkansas Department of Health (ADH) was notified by a northeast Arkansas primary care provider of a cluster of three histoplasmosis cases. On November 4, ADH was notified by a pediatric infectious diseases specialist regarding seven potential cases of pulmonary histoplasmosis associated with a family gathering that included a bonfire that burned bamboo from a grove that had been a red-winged blackbird roost. These reports prompted an outbreak investigation to ensure that the persons involved received appropriate medical care, to identify whether any novel exposures were associated with illness, and to determine whether any factors were associated with hospitalization. The investigation found that, among the 19 attendees at the family gathering, seven were confirmed with histoplasmosis, 11 were probable, and one did not have histoplasmosis.

Multiple-serotype salmonella outbreaks in two state prisons--Arkansas, August 2012.

In August 2012, the Arkansas Department of Health (ADH) was notified of gastrointestinal illness outbreaks in two Arkansas state prisons. ADH investigated the outbreaks and conducted case-control studies to identify the source of the illnesses. This report describes the results of these investigations, which identified 528 persons with onset of diarrhea during August 2-18, 2012. Results from the prison A investigation identified chicken salad as the most likely vehicle. At prison B, person-to-person transmission and contamination of multiple foods likely contributed to illness. Analysis of stool specimens from inmates identified eight serotypes and 15 pulsed-field gel electrophoresis (PFGE) patterns of Salmonella. Isolates of Salmonella from eggs produced at prison B matched two outbreak patterns. An additional 69 inmates were positive by culture but were not interviewed or did not report diarrhea, making the total case count 597. Sanitarians identified problems with food preparation, hand washing, and food safety training. ADH tested inmate kitchen workers, excluded infected inmates from work, and provided food safety training. Prison kitchen staff should follow guidelines consistent with state regulations for safe food preparation and pass sanitarian inspection.

Influenza a outbreak in an ambulatory stem cell transplant center.

BACKGROUND: In the era of cost-consciousness regarding healthcare , provision of medical services in an outpatient setting has become increasingly attractive. We report an influenza outbreak in an ambulatory stem cell transplant center in 2013 that highlights unique identification and infection control challenges in this setting. METHODS: Nasopharyngeal swabs were performed on patients with suspected influenza-like illnesses (ILI), defined by subjective fever or measured temperature of ≥37.7°C (≥100°F) with cough or sore throat during July 25, 2013 through August 7, 2013. In addition, testing was triggered by an elevated C-reactive protein (CRP). Specimens were analyzed by using eSensor Respiratory Viral Panel. Clinical and epidemiologic information was collected in real time, and frequencies were calculated on demographics, baseline clinical parameters, treatment methods, comorbidities, and symptoms of affected persons. RESULTS: Thirty-one patients had influenza A (H3N2) infection during July 25, 2013 through August 7, 2013. Only 7 patients (23%) met the Centers for Disease Control and Prevention and Council of State and Territorial Epidemiologists ILI case definition. Twenty-five patients (81%) had received ≥1 transplant, with 13 (42%) having occurred within 1 year before the outbreak. Twenty-five patients (81%) had received B-cell active chemotherapy <60 days before influenza diagnosis, 6 (19%) were neutropenic, and 25 (81%) lymphopenic. Among clinical and laboratory markers analyzed, abnormal CRP was the most sensitive screening tool for influenza. Twelve (39%) patients were hospitalized (median stay, 10 days; range, 2-20). No deaths occurred. CONCLUSIONS: Immunocompromised hosts with influenza have atypical presentations. Existing surveillance case definitions might be insufficient to reliably identify influenza outbreaks in such patients.

One dose of varicella vaccine does not prevent school outbreaks: is it time for a second dose?

OBJECTIVES: The implementation of a routine childhood varicella vaccination program in the United States in 1995 has resulted in a dramatic decline in varicella morbidity and mortality. Although disease incidence has decreased, outbreaks of varicella continue to be reported, increasingly in highly vaccinated populations. In 2000, a varicella vaccination requirement was introduced for kindergarten entry in Arkansas. In October 2003, large numbers of varicella cases were reported in a school with high vaccination coverage. We investigated this outbreak to examine transmission patterns of varicella in this highly vaccinated population, to estimate the effectiveness of 1 dose of varicella vaccine, to identify risk factors for vaccine failure, and to implement outbreak control measures. METHODS: A retrospective cohort study involving students attending an elementary school was conducted. A questionnaire was distributed to parents of all of the students in the school to collect varicella disease and vaccination history; parents of varicella case patients were interviewed by telephone. A case of varicella was defined as an acute, generalized, maculopapulovesicular rash without other apparent cause in a student or staff member in the school from September 1 to November 20, 2003. Varicella among vaccinated persons was defined as varicella-like rash that developed >42 days after vaccination. In vaccinated persons, the rash may be atypical, maculopapular with few or no vesicles. Cases were laboratory confirmed by polymerase chain reaction, and genotyping was performed to identify the strain associated with the outbreak. RESULTS: Of the 545 students who attended the school, 88% returned the questionnaire. Overall varicella vaccination coverage was 96%. Forty-nine varicella cases were identified; 43 were vaccinated. Three of 6 specimens tested were positive by polymerase chain reaction. The median age at vaccination of vaccinated students in the school was 18 months, and the median time since vaccination was 59 months. Forty-four cases occurred in the East Wing, where 275 students in grades kindergarten through 2 were located, and vaccination coverage was 99%. In this wing, varicella attack rates among unvaccinated and vaccinated students were 100% and 18%, respectively. Vaccine effectiveness against varicella of any severity was 82% and 97% for moderate/severe varicella. Vaccinated cases were significantly milder compared with unvaccinated cases. Among the case patients in the East Wing, the median age at vaccination was 18.5 and 14 months among non-case patients. Four cases in the West Wing did not result in further transmission in that wing. The Arkansas strains were the same as the common varicella-zoster virus strain circulating in the United States (European varicella-zoster virus strain). CONCLUSIONS: Although disease was mostly mild, the outbreak lasted for approximately 2 months, suggesting that varicella in vaccinated persons was contagious and that 99% varicella vaccination coverage was not sufficient to prevent the outbreak. This investigation highlights several challenges related to the prevention and control of varicella outbreaks with the 1-dose varicella vaccination program and the need for further prevention of varicella through improved vaccine-induced immunity with a routine 2-dose vaccination program. The challenges include: 1-dose varicella vaccination not providing sufficient herd immunity levels to prevent outbreaks in school settings where exposure can be intense, the effective transmission of varicella among vaccinated children, and the difficulty in the diagnosis of mild cases in vaccinated persons and early recognition of outbreaks for implementing control measures. The efficacy of 2 doses of varicella vaccine compared with 1 dose was assessed in a trial conducted among healthy children who were followed for 10 years. The efficacy for 2 doses was significantly higher than for 1 dose of varicella vaccine. This higher efficacy translated into a 3.3-fold lower risk of developing varicella >42 days after vaccination in 2- vs 1-dose recipients. Of the children receiving 2 doses, 99% achieved a glycoprotein-based enzyme-linked immunosorbent assay level of > or =5 units (considered a correlate of protection) 6 weeks after vaccination compared with 86% of children who received 1 dose. The 6-week glycoprotein-based enzyme-linked immunosorbent assay level of > or =5 units has been shown to be a good surrogate for protection from natural disease. Ten years after the implementation of the varicella vaccination program, disease incidence has declined dramatically, and vaccination coverage has increased greatly. However, varicella outbreaks continue to occur among vaccinated persons. Although varicella disease among vaccinated persons is mild, they are contagious and able to sustain transmission. As a step toward better control of varicella outbreaks and to reduce the impact on schools and public health officials, in June 2005, the Advisory Committee on Immunization Practices recommended the use of a second dose of varicella vaccine in outbreak settings. Early recognition of outbreaks is important to effectively implement a 2-dose vaccination response and to prevent more cases. Although the current recommendation of providing a second dose of varicella vaccine during an outbreak offers a tool for controlling outbreaks, a routine 2-dose recommendation would be more effective at preventing cases. Based on published data on immunogenicity and efficacy of 2 doses of varicella vaccine, routine 2-dose vaccination will provide improved protection against disease and further reduce morbidity and mortality from varicella.