March 11, 2005

Epi Update Managing Staff:

John A. Agwunobi, MD, MBA, MPH, Secretary, Florida Department of Health
Landis Crockett, MD, MPH, Director, Division of Disease Control
Dian K. Sharma, MS, PhD, Bureau Chief, Bureau of Epidemiology, Editor-in-Chief
Jaime Forth, Managing Editor

"The reason for collecting, analyzing and disseminating information on a disease is to control that disease. Collection and analysis should not be allowed to consume resources if action does not follow."

                                        Foege WH., International Journal of Epidemiology 1976; 5:29-37



Outbreak of Norovirus Gastroenteritis,
St. Augustine, Florida - January 2005
 by Aimee Pragle, MSEH, et. al.
                           

Introduction:
On Tuesday, January 25, 2005, the St. Johns County Health Department (SJCHD) received a complaint of gastrointestinal illnesses among members of a professional association attending their annual conference held the week of January 18 - 21, 2005 at a local resort. Approximately 150 members and 60 persons representing vendors and exhibitors participated in the conference. Multiple meals were provided at the resort during the conference. Other meals were consumed at various local restaurants by attendees. One vendor hosted a group of 40 Association members to a luncheon at a local restaurant on Thursday January 20. 

Methods:
The Environmental Health Program Supervisor, (SJCHD Environmental Health Division), Epidemiology Program nurse (SJCHD Epidemiology Division), Regional environmental epidemiologist (Bureau of Community Environmental Health, Florida Department of Health), and Northeast Florida Epidemic Intelligence Service fellow (Bureau of Epidemiology, Florida Department of Health) began an epidemiological investigation on Wednesday, January 25.  

A list of the email addresses for the 150 members and 60 persons representing vendors were provided to the SJCHD by the association. Case finding was initiated on January 25 with an email sent to each addressee requesting they contact the St. Johns County Health Department. A second email was sent to non-respondents. Questionnaires were administered by telephone to the seventy-three attendees who responded to the email.  

A case was defined as any attendee of the conference experiencing three or more episodes of vomiting and/or diarrhea and/or any three of the following symptoms: nausea, low-grade fever, cramps, headache, chills or fatigue between January 20 and January 27, 2005. Fifteen respondents met the case definition. 

The Florida Department of Business and Professional Regulation (DBPR) conducted an inspection of the resort food service facilities as well as the local restaurant where a luncheon was held on January 25 and conducted sanitation and employee hygiene training on January 27. A joint meeting with SJCHD staff, the regional environmental epidemiologist, DBPR and resort management staff was also held on January 27 to discuss the investigation and provide appropriate information for management of ill employees and /or guests.  Statistical analysis of the data obtained from the interviews was conducted using EpiInfo 2000. 

Results:
Of the seventy-three attendees interviewed, fifteen reported having gastroenteritis (21%). The onset date of illness for conference attendees was January 21 (Figure 1). The most commonly reported symptoms were diarrhea (100%), abdominal cramps (93%), fatigue (93%) and nausea (86%: Table 1). The average duration of illness was three to four days. 

Statistical analysis of data showed a risk association of illness with consumption of the Thursday, January 20 luncheon at the local restaurant (OR = 9.41, p-value = 0.0003; Table 2). Meals consumed at the resort or other restaurants showed no significant risk for illness.  

Three stool samples were collected and analyzed for bacterial and viral pathogens. Results of the laboratory analysis of the stool samples showed that two of the three were positive for G2 Norovirus and negative for bacterial pathogens.  

There were also several reports of secondary cases of gastroenteritis among family members of ill persons as well as illness among some of their coworkers who did not attend the conference.  

Conclusions:
This investigation has determined that the illnesses occurring among the association conference attendees was a point source outbreak of Norovirus gastroenteritis associated with attending a vendor hosted luncheon and consumption of ready-to-eat foods at the local restaurant on Thursday, January 20. Statistical analysis results indicate those attending the luncheon were 9 times as likely to become ill compared to those who did not attend.  Consumption of ready–to-eat foods had a significantly higher risk of illness with an odds ratio of 48.00 (p-value 0.0001; Table 3). The symptomology, incubation and duration times of the illnesses as well as secondary cases among family members and co-workers are consistent with Norovirus infection. Two stool samples were confirmed positive for G2 Norovirus. 

Point source outbreaks of Norovirus are typically associated with contaminated foods, particularly ready-to-eat items. Such contamination is the result of poor hygiene and inadequate hand washing by infected food workers.

Management staff of the implicated restaurant reported no employees having or complaining of gastrointestinal illness during that time, although there was discussion about a worker with an ill child. The source of the contamination is unknown. 

Recommendations:
Norovirus is an enteric virus of human origin only. It is shed in human feces during infection in high numbers and can continue to be shed for up to 22 days after symptoms have ceased. It is highly infective even at doses as low as 10 viral particles. Fecal contamination of hands after toilet use and subsequent lack of hand washing or inadequate hand washing can spread viral particles to foods, surfaces and to other persons. Norovirus is also effectively spread to persons or surfaces by aerosolization during vomiting. This often accounts for the secondary transmission of Norovirus to persons that care for or clean up after ill family members. 

Norovirus particles are very hardy, resistant to chlorine and can remain viable outside of the human host for weeks. Proper hand washing after toilet use is the best method for preventing food borne Norovirus infection. Hand washing is especially critical prior to preparation of foods.  

Food service workers who are ill with gastrointestinal symptoms must be restricted from duties during illness. Norovirus can continue to be shed fecally for up to 22 days after infection; therefore, ill workers must be restricted from food preparation and serving duties for at least 72-96 hours after cessation of symptoms.

              10th Bureau of Epidemiology Seminar
                               Set for May 17-18
                                                           by Melanie Black, MSW

              
The 10th Epidemiology Statewide Seminar, "Emerging Issues in Epidemiology," will be held at the Orlando Marriott Hotel in Lake Mary, Florida, 15 miles NE of downtown Orlando on May 17-18, 2005. Syndromic surveillance, antibiotic resistance, lab development of diseases associated with bioterrorism, hurricane related BRFSS data, asset typing, Avian flu, competencies and applied epidemiology, maternal child health obesity and diabetes contributions to maternal morbidity, and carbon monoxide poisoning are among just some of the issues that will be discussed.

The evening of May 16th there will be a cook-out and the opportunity to pre-register for the first day. The poster session and reception will be held the evening of May 17th. The poster event will be judged again this year, with awards given for the best communicable disease poster, as well as for the best presentation by a Florida EIS fellow, the best chronic disease poster and the best county health department display. Two additional categories have been added, one for environmental health and the other for spatial analysis/visualization. The winners will be announced at the following day’s luncheon.

The “County Showcase” and “Golden Partnership” awards will be featured again this year as well. The County Showcase provides county health departments the opportunity to bring educational resources they have developed for healthcare professionals, and share them with others. These items will be on display throughout the seminar. If you would like to participate in this event, please contact Melanie Black. The Golden Partnership awards will be presented during the opening ceremonies to partners who have made significant contributions in support of disease surveillance and epidemiology.

To take advantage of the special group rate of $71.00 for hotel accommodations, be sure to make your reservations early. Call the Marriott directly at 407.995.1100 or through their toll-free reservation line at 800.380.7724 and refer the booking agent to the Florida Department of Health, Bureau of Epidemiology Seminar, code FDO to receive the group rate. You can also reserve accommodations through the hotel website at marriott.com/MCOML. . On the right side of the screen under “check rates and availability”, enter the dates you plan to arrive and depart. In the box labeled “Group Code” enter FDOFDOA and then click on the red button “Find”. Verify the information and complete the reservation by clicking on the red button “Reserve a Room”. A confirmation number should appear at the end of the process.

Further information can be found on the Bureau of Epidemiology Internet website
http://www.doh.state.fl.us/disease_ctrl/epi/conf/training/index.htm, or contact Melanie Black at the Bureau of Epidemiology in Tallahassee at 850.245.4444, ext. 2448.
                 
Melanie Black is the professional training coordinator at the Bureau of Epidemiology in Tallahassee and plans the annual statewide seminar each year. Contact her via email at melanie_black@doh.state.fl.us
 

         
On-call Procedures for Possible Avian Flu Available on
Bureau Website
by Jaime Forth

A policy advising health care givers of the need to contact the state Division of Disease Control prior to conducting tests for avian flu has been released this week. The document, promulgated by Dr. Joann Schulte, medical epidemiologist at the Bureau of Epidemiology and others on her investigative team, also provides guidance on preparation of specimens for virus isolation and other key elements of an investigation into an avian respiratory illness.

The document, posted at http://www.doh.state.fl.us/disease_ctrl/epi/htopics/BirdFlu.htm, presents a series of questions which should be asked of potential patients cases. In addition to verifying the patient's place of domicile, whether they have been hospitalized and the name of the admitting physician, clinicians are directed to learn the patient's recent travel history or whether he has been exposed to someone recently returned from SE Asia; whether there was contact with farm animals in that country; and whether there was an outbreak of influenza-like illness at any place the patient has recently visited. A complete list of questions is posted at the website.

Specific instructions for collection and shipping of specimens to state laboratories in Jacksonville and Tampa, and a PowerPoint presentation on the etiology and epidemiology of avian influenza are also posted on the website. In addition, links to the CDC and World Health Organization are provided. For more details or consultation, contact the on-call epidemiologist at 850.245.4444, ext. 4401.

Jaime Forth is managing editor of Epi Update and can be reached at 850.245.4444, ext. 2440.

         Bureau of Epidemiology Announces Poster
                    Competition for 2005 Seminar
                                                           by Melissa Murray, MS

The Bureau of Epidemiology is actively seeking posters for its annual seminar in Lake Mary, Florida, scheduled for May 17-18, 2005.

Poster presentations give conference attendees a great opportunity to share research with colleagues and friends. Examples of poster topics include results of an outbreak investigation, new prevention programs at the local level or new laboratory methods in disease control. The session also presents an opportunity to demonstrate new computer and Web-based systems related to public health.

Format for posters will follow the basic scientific paper outline, where applicable:

Background – the problem under investigation or hypothesis

Methodology – the experimental methods used, including type of study, number of cases, etc.

Results – a summary of essential results

Conclusions/Recommendations – summary of findings, supported by your results (the conclusions should be numbered if multiple points are presented) along with the public health/policy implications of your research

The poster session and reception will occur the evening of May 17th; however, participants will be asked to set up their posters on May 16th so judges will have sufficient time to view all entries. Posters can be displayed in a three-fold form board format or a flat poster board. Electricity and/or Internet connections will not be provided. Be sure to have a primary and secondary point of contact for presenting your poster.

When submitting your abstract you will be asked to select a category which best describes your poster from the following list: Chronic Disease, Florida EIS, Spatial Analysis/Visualization, County Health Department, Environmental Health or Communicable Disease. Please indicate your selected category in the subject line or text of your email when you submit the abstract.

More specific details regarding abstract submission will be included in next week's Epi Update. The abstract submission deadline is April 15th. Please submit your abstract via email to Melissa Murray at melissa_murray@doh.state.fl.us. If you have any questions, contact Melissa by email or call 850.245.4444, ext. 2445.

Melissa Murray is coordinator of research services at the Bureau of Epidemiology. She can be reached at 850.245.4444, ext. 2445.

Bureau of Epidemiology Grand Rounds on Childhood Morbidity Scheduled for March 29
by Matt Laidler, MA, MPH

Abstract:
This presentation describes a spatial analysis of the 5 leading causes of childhood morbidity in Florida as reported to the Bureau of Epidemiology through the Merlin system. The units of analysis were rates of morbidity within zip code areas throughout the state. A spatial scan test was used to identify where local clusters of incidence occur, the rates identified within these clusters, and the amount of aggregate incidence explained by the cases within the detected clusters. Statistically significant incidence clusters were detected for all 5 of the leading causes of morbidity in persons under 18 years of age. Incidence in some of the significant clusters accounts for nearly 50% of the aggregate (state-wide) incidence for particular diseases. It is suggested that addressing prevention/intervention in these areas could reduce a substantial proportion of aggregate incidence, although typical approaches may vary.

• Hepatitis A at a school in Duval County
• Hepatitis B at a physician's office in Miami-Dade County
• N. meningitides in a 12-year old in Lee County is under investigation
• Confirmed case of Neisseria meningitides in 15 year-old male identified in Monroe County

Pete Garner is administrator of the Bureau of Epidemiology Surveillance Systems Section in
Tallahassee.  He can be reached at 850.245.4444, ext. 2481.

Mosquito-borne Disease Update  February 27 - March 5, 2005
Caroline Collins, BS; Kristen Payne; Calvin DeSouza; Carina Blackmore, DVM, PhD

Weekly Update: During the period February 27 - March 5, 2005, the following arboviral activities (St. Louis encephalitis (SLE) virus, eastern equine encephalomyelitis (EEE) virus, Highlands J (HJ) virus, West Nile (WN) virus and dengue virus) were recorded in Florida.

WN virus activity: Three seroconversions to WN were confirmed in sentinel chickens from Pinellas and N. Walton Counties this week.

EEE virus activity: Two seroconversions to EEE were confirmed in sentinel chickens from St. Johns County this week.

SLE virus activity: None yet this year.

HJ virus activity: None this week.
 

There are no counties currently under medical alert for mosquito-borne disease. Cooler weather in many parts of the state is helping to reduce mosquito populations. Where mosquitoes are present, people are urged to take precautions against getting bitten.

Dead birds should be reported to www.wildflorida.org/bird/. See the web page for more information at www.MyFloridaEH.com. The Disease Outbreak Information Hotline offers recorded updates on medical alerts status and surveillance at 888.880.5782.

The arbovirus surveillance program is staffed by the Division of Environmental Health and can be reached at 850.245.4299.

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