Division of Disease Control and Health Protection

The Epidemiology Grand Rounds, a monthly, one-hour audio-conference to be conducted by the Bureau of Epidemiology, will focus on issues of epidemiologic interest to Florida public health providers, including; county health department directors and administrators, nursing directors and nurse epidemiologists, laboratorians, and others who may be interested. Each session will feature a formal Powerpoint presentation (materials will be distributed before the call), followed by an opportunity for audience interaction. Presenters will include representatives of the State Department of Health, county health departments, schools of public health and other experts in epidemiology and associated specialties.

The inaugural session will be March 30^th, at which time Dr. Ursula Bauer, Chronic Disease Epidemiologist for the Bureau of Epidemiology will present "Results of the 1999 Florida Youth Tobacco Survey." Further details regarding the audioconference call and Powerpoint files are posted at DOH intranet website http:dohiws.doh.state.fl.us. Upcoming topics and presenters will also be posted at this site in the future. Powerpoint files will also be attachments included with future Epi Updates.

Time: 11:00 AM - 12:00 PM. The same number is established for all calls.

1999 Audioconference Dates:

April 27

May 25

June 29

July 27

August 31

September 28

October 26

November 30

December 28

The first report from the 1999 Florida Youth Tobacco Survey was released by Secretary Robert Brooks at a press conference at the Capitol on Tuesday, March 23. The report is available on the world wide web at www.state.fl.us/tobacco. Click on "research" and select "1999 FYTS Report #1"

The report summarizes results from the 1998 and 1999 surveys, which show that the percent of Florida public middle and high school students who used cigarettes during the 30 days preceding the survey decreased significantly from 1998 to 1999. Use of cigars and smokeless tobacco products also declined substantially among middle school students.

Prevalence of cigarette use among middle school students declined from 18.5% in 1998 to 15.0% in 1999 (p<0.0001) (table 1-see report). Among high school students, current cigarette use declined from 27.4% in 1998 to 25.2% in 1999 (p<0.02) (Table 2-see report). Among middle school students, declines in current cigarette use were substantial and significant for both males and females; however, among high school students, the decline was statistically significant only among females. Among both middle and high school students, the declines were most pronounced among non-Hispanic white students. Current cigarette use among non-Hispanic white middle school students declined from 22.0% in 1998 to 16.1% in 1999 (p<0.0001), and from 34.8% in 1998 to 31.1% in 1999 among non-Hispanic white high school students (p<0.02). There was no statistically significant change in prevalence of current cigarette use among non-Hispanic black or Hispanic students at the middle or high school level. Prevalence of cigarette use in these groups was lower than among non-Hispanic whites in both 1998 and 1999.

Current cigar use declined significantly only among middle school students. Among this group, current cigar use declined from 14.1% in 1998 to 11.9% in 1999 (p<0.0002). This overall decline was almost entirely accounted for by the decline among males, from 17.6% in 1998 to 14.2% in 1999. Among race/ethnic groups at the middle school level, the decline in current use of cigars was statistically significant only among non-Hispanic white students.

Current smokeless tobacco use declined among middle school students, among whom 6.9% were current users in 1998 and 4.9% were current users in 1999. The decline was evident in both male and female middle school students, and among non-Hispanic white and Hispanic middle school students. Students at every grade in middle school were significantly less likely to use smokeless tobacco products in 1999 compared to 1998. Current use of smokeless tobacco products remained unchanged among high school students from 1998 to 1999.

The results are encouraging for the Department’s Office of Tobacco Control, which implemented a multi-faceted, youth-oriented tobacco use prevention program in April 1998. No other state that has mounted comprehensive tobacco use prevention and education efforts has observed one-year declines in cigarette use of the magnitude seen in Florida between 1998 and 1999. Whether the declines can be sustained remains to be seen. As other states release the results of their youth tobacco surveys, and as other components of the Florida program’s on-going evaluation are reported, the impact of this program can be assessed.

A conference was held in a Volusia County hotel from January 18 through January 22, 1999. Conference attendees were individuals from throughout the state of Florida.

Several days after the conference ended, the Volusia County Health Department began to receive reports of respiratory tract infections in conference attendees. An initial estimate of the number who had become ill was 100. An environmental inspection of the hotel indicated that it was most likely not the source of infection. The illness appeared to be influenza. The Bureau of Epidemiology was notified on January 28, 1999. An investigation was conducted to determine the extent and cause of the outbreak.

A retrospective cohort study was conducted to determine the overall attack rate of influenza-like illness (ILI) in conference attendees, and also the relative risk of ILI for individuals vaccinated with the 1998-99 influenza vaccine compared to non-vaccinees. Two ILI case definitions were used during this investigation: 1) fever (unrecorded) and cough or sore throat, and 2) fever (³ 100 degrees) and cough or sore throat. The second case definition is the one that is being used by physicians participating in the U.S. Influenza Sentinel Physician Surveillance Network.

A total of 263 individuals registered for the conference. The inclusion criteria were: 1) the registered individual must have attended at least one day of the conference, and 2) the individual must have been free of fever, cough, and a sore throat at the time of arrival at the conference. Forty-six eligible individuals were interviewed.

A single individual (Z.D.M.) interviewed all of the study participants. Exposure status (vaccination status) and the outcome (onset of ILI during the conference or within three days of leaving the conference) were obtained via phone interviews using a questionnaire. Age and smoking status were also recorded because they were potential confounders of the association between vaccination status and risk of ILI. Smoking status was a binary variable (Yes or No) and was defined as having smoked a cigarette, pipe, or cigar at least once during the four weeks preceding the conference or during the conference. The Epi Info software package (Version 6.04b) was used for data entry and univariate analyses.

An overall attack rate was calculated from the sample and the 90% confidence interval was calculated using the normal approximation to the binomial. Attack rates of ILI by vaccination status and the crude relative risk of ILI were calculated. PROC LOGISTIC in the SAS system [1] was used to perform simple and multiple logistic regression. Odds ratios and 90% confidence intervals were calculated in the traditional manner. The presence of confounding was assessed by the change-in-estimate method described by Greenland [2]. Age and smoking status were removed from the full model (vaccination status, age, and smoking) and the change in the odds ratio associated with the vaccination parameter was examined. If there was a ³ 10% change between the odds ratios from the full and reduced models, then joint confounding was present and an adjusted odds ratio was reported. Vaccine efficacy was calculated as 100(1 - 1/adjusted odds ratio for ILI).

Paired sera (acute and convalescent) were obtained from two ill attendees who were not interviewed. These sera were collected approximately 10 and 24 days after onset of symptoms and sent to the State Public Health Laboratory in Jacksonville for analysis. A respiratory panel for antibodies to influenza A and B virus, parainfluenza 3 virus, adenovirus, cytomegalovirus, and Mycoplasma pneumoniae was performed using the complement fixation test.

Eighteen of the 46 study participants reported having a fever during the conference or within three days of leaving the conference. However, only eight of the 18 individuals had measured their temperature; therefore, only the first case definition was used during data analysis.

Seventeen cases were identified in the study sample. The overall attack rate of ILI was 37% (90% confidence interval: 25% - 49%). The epidemic curve below indicates that this was a common source outbreak with an incubation period of three days.

Table 1 displays selected characteristics of the 46 conference attendees by vaccination status. Non-vaccinees were more likely than vaccinees to be younger, female, and smokers.

The attack rate in non-vaccinees was 44.1% and 16.7% in vaccinees (chi-square p-value=0.09). The crude relative risk of ILI (non-vaccinees versus vaccinees) was 2.65.

Odds ratios for ILI (non-vaccinees compared to vaccinees) calculated from logistic regression models are shown in Table 2. The crude odds ratio for ILI was 3.95. This result approached statistical significance at the alpha=0.10 level. After adjusting for age and smoking status, the odds ratio was 4.37. This result was statistically significant at the 0.10 level. Vaccine efficacy was 77.1%.

Both patients had antibody titers to Influenza A. However, neither of the patients had a fourfold difference in titers between the acute and convalescent sera. The titers from patient A were high (1:128/ 1:256) indicating a recent influenza A infection. Patient B had lower titers (1:32/ 1:32), lower than the titer normally seen in patients infected by the influenza A virus. Subsequently, we were not able to confirm the diagnosis of ILI for our second patient (patient B). Antibody titers to adenovirus, cytomegalovirus, parainfluenza 3 and Mycoplasma pneumoniae were negative.

We report an outbreak of influenza-like illness in a cohort of conference attendees. The results of this study indicate that non-vaccinees were more likely to develop ILI than vaccinees during and immediately following this conference. The source of the outbreak is unknown but may have been one or more attendees who arrived at the conference with subclinical disease.

Limitations include a small sample size and, as in many outbreak investigations, the study sample was not a random sample and therefore may not be representative of the population of conference attendees. The acute laboratory samples were also obtained late, more than a week after onset of symptoms. Acute sera or swabs for virus isolation should, if possible, be obtained within three days after onset.

In conclusion, individuals who are experiencing ILI should refrain from activity that brings them into contact with the public. The Advisory Committee on Immunization Practices issued recommendations for the prevention and control of influenza in 1998. These can be found in the May 1, 1998, Volume 47, No. RR-6, issue of the CDC’s Morbidity and Mortality Weekly Report. This report is on the Internet at http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/00052500.htm

1. SAS Institute Inc. The LOGISTIC Procedure. SAS/STAT User’s Guide, version 6. Fourth edition. V. 2. Cary, NC: SAS Institute Inc., 1989: 1071-1126.
2. Greenland S. Modeling and variable selection in epidemiologic analysis. American Journal of Public Health, 1989; 79:340-349.

Rotavirus has emerged as the most important cause of severe diarrhea in children worldwide. It is a problem not only in developing countries, where it is responsible for an estimated 870,000 deaths in children each year, but also in the US, where it remains the most important single cause of hospitalization or clinic visits for childhood diarrhea. Virtually all children become infected in the first 3-5 years of life, but severe diarrhea and dehydration occur primarily in children aged 3-35 months.

Rotaviruses are shed in high concentrations in the stools of infected children and are transmitted by the fecal-oral route, both through close personal contact and through fomites. In the US this virus causes seasonal peaks of gastroenteritis from November to May each year, with activity highest during the winter months. Anecdotal evidence indicates that the seasonal peak for rotavirus gastroenteritis in Florida is perhaps a month (March) later this year and possibly more severe than in the previous two years.

Although rotavirus gastroenteritis results in relatively few deaths (approximately 20 per year among children< 5years of age) in the US, it accounts for more than 500,000 physician visits and 50,000 hospitalizations each year among children aged less than 5 years. Among children aged less than 5 years, 72% of rotavirus hospitalizations occur during the first 2 years of life, and 90% occur by age 3 years.

The Advisory Committee on Immunization Practices (ACIP) sees several reasons for adopting immunization of infants as the primary public health intervention to prevent rotavirus disease in the US: 1) the large burden of disease, both in direct medical costs and societal costs; 2) clean water supplies and good hygiene have not decreased the incidence of rotavirus diarrhea in developed countries; and 3) a high level of rotavirus morbidity continues to occur despite currently available therapies.

There have been several vaccines developed, and one was found to be safe and efficacious in clinical trails among children in North and South America and in Europe. Based on these studies it is now licensed for use among infants in the US. The vaccine is an oral, live preparation that should be administered between the ages of 6 weeks and 1 year in a three-dose series – doses administered at 2, 4, and 6 months. The vaccine contains the four virus strains known to commonly circulate in the US. Although there have been additional human strains plus some animal strains found, these rarely appear to cause infection in humans.

A national rotavirus immunization program has been estimated to result in 227,000 fewer physician visits, 95,000 fewer emergency room visits, 34,000 fewer hospitalizations, and 13 fewer deaths per year. A more complete discussion of the ACIP recommendations can be found at: http://www.cdc.gov/epo/mm

National: Influenza activity levels remained high during week 10 but are declining. Thirty-four states reported regional or widespread activity compared to 44 states during week 5, as reported by state and territorial epidemiologists appears to have peaked.. The WHO laboratories reported that 14% (8,798 of 60, 981) of the specimens tested since October 4 have been positive for influenza. Seventy eight percent (6,833) of these were influenza A. Among the type A viruses, 26% have been subtyped. Subtype A(H3N2) has predominated (99% of 1,795)). Thirteen isolates have been subtyped as A(H1N1) So far this season, influenza A has been the most common subtype in the U.S. overall and in all of the nine regions; however the percentage of influenza type A viruses have varied by region, ranging from 58% in the East North Central region to 92% in the Mid-Atlantic region. Influenza B has predominated in some regions during specific time periods. Of the total patient visits to sentinel physicians, 3% were due to ILI (influenza-like-illness) in the U.S. overall. The percentage of patient visits was within baseline values of 0%-3% in six of the nine regions. It the South Atlantic and East South Central and West South Central region the percentages were 4%, 7% and 8% respectively. The percentage of pneumonia and influenza deaths reported from the 122 cities during Week 10 was 8.7 %, above the epidemic threshold of 7.5%. This is the fifth consecutive week in which the percentage of pneumonia and influenza deaths has exceeded the epidemic threshold.

Florida During week 10 (7-13 March 1999) there were 7 laboratory-confirmed isolates of influenza reported: Influenza A were reported from Broward (AH1N1, AH3N2), Hillsborough, Orange, Osceola (AH3N2) and Palm Beach counties. Since September 23 and to date, there have been 199 isolates reported; 64 (32%) of these were type B, 57 (29%) were type A(H3N2), 5 (3%) was type A(H1N1). Isolates have been reported from: Alachua (1), Brevard (5), Broward (25), Dade (5), Desoto (1), Duval (14), Hillsborough (46), Indian River (5), Leon (18), Martin (1) Okaloosa (2), Orange (20), Palm Beach (16), Pinellas (12), Polk (4), Sarasota (19), Seminole (2), St. John’s (1) and Volusia (2) counties.

Of the total patient visits to sentinel physicians during Week 10, 2% were due to ILI. This is within the baseline levels of 0-3%. Since October 4 the percentage has ranged between 1 and 4%. Influenza-like illness has been reported from health care providers in 20 of the 21 Florida counties in the sentinel physician surveillance network.

The rabies guidebook, Rabies Control and Prevention in Florida, 1999 is being distributed to county health departments for further circulation. It is also available on the Department of Health Website http://www.doh.state.fl.us/disease_ctrl/epi/Rabies%20Guidebook/rabies99.pdf

Additionally, the national Advisory Committee on Immunization Practises recommendations regarding rabies prevention in humans is available on the CDC MMWR website: http://www.cdc.gov/epo/mmwr/preview/mmwrhtml/00056176.htm

The Department of Health’s Internet (www.doh.state.fl.us) site provides information about the "Florida Symposium: The Health and Medical Response to Biological Terrorism and Weapons of Mass Destruction." This meeting will be held May 6-7, 1999 at the Hyatt Regency Tampa Hotel. Registration forms and additional information are provided on the DOH websites.

A Lee County resident died on Monday after a febrile illness with encephalitis. Initial laboratory work suggested St. Louis encephalitis (SLE) as the cause of his illness. However, when sera were retested at the DOH Jacksonville Laboratory, no evidence of acute SLE virus infection was found. Had the results been positive, this would have been an unusual event as the disease is extremely rare in the cooler months and the Lee County Mosquito Control sentinel surveillance program has not detected unusual SLE activity this winter.

Information on SLE and other arbo viruses is available in the "Surveillance and Control of Selected Arthropod-borne Diseases in Florida, 1999" on the Burea of Epidemiology website: http://www.doh.state.fl.us/disease_ctrl/epi/arbo99.pdf

Whereas, Hurricane Andrew's powerful destructive force caught Floridians

unprepared, causing hundreds of millions of dollars in damages to property

and an untold amount of animal and human suffering; and

Whereas. The animal / human bond has been well documented showing the

reluctance of animal owners to separate from their animals during disasters;

and

Whereas Research shows that over fifty-percent of Florida's population owns

one or more family pets; and

Whereas Florida's agricultural animal population is estimated at more than

2.4 million head of livestock (beef and dairy cattle, horse, and swine), and

144 million poultry, with cash receipts of over $1.2 billion in 1997; and

Whereas Proper planning and practice will reduce the lose of human and

animal life, and property; and

Whereas When persons develop animal disaster plans for their animals they

also develop family disaster plans.

NOW, THEREFORE, BE IT RESOLVED that the Governor and the Cabinet of the

State of Florida do hereby commend the Florida Department Of Agriculture and

Consumer Services, The Humane Society of the United States, local Disaster

Animal Response Teams volunteers and others for their efforts to protect the

animal population of Florida from natural and man-made disasters.

BE IT FURTHER RESOLVED that the Governor and the Cabinet declare the last

week of March as Animal Disaster Preparedness Week in Florida and encourage

every animal owner in Florida to develop disaster plans for their animals

and families.

"This has been a large part of unfinished business of the Bureau for many years and no amount of coaxing, pleading, wheedling, etc. has been sufficient to educate the "Educational" authorities to the necessity of safe water supplies and sanitary toilets for schools.

During 1933, in cooperation with the State Department of Public Instruction, plans were made available to all county school superintendents for sanitary toilets. If one was built there is no record of it. During the CWA (Civilian Work Authority) an effort was made to have schools take advantage of that opportunity to improve their sanitary facilities. Less than 20 percent of the counties replied to the letter……..and many of these replies came too late to permit a survey of requirements, leaving no time to do the work.

In June 1934, a complete pamphlet, covering water supplies, their protection and distribution, and sanitary toilets and their construction, was prepared and distributed to every county superintendent. This followed a letter from the State Health Officer, approved by the President of the State Board of Health, to the State Superintendent of Public Instruction, a copy of which was sent to each county superintendent, advising that schools not properly equipped with water supply and sanitary toilets would not be permitted to continue during the 1934-35 session.

Some cooperation has been received under this program. To obtain a picture of the needs of the schools a brief survey….was (conducted)……….

More than one half of all (2179) schools (inspected) get their water from unprotected springs and dug wells, are equipped with common pitcher pumps, or have no water supply at all. The drinking water distribution to pupils was satisfactory in only about 11 per cent of the schools. More than 50 percent of all were equipped with upright bubblers, inverted faucet, or the pupils drank directly from the pump spout. This was approximately 70% of all schools having water supplies. In an analysis of sewerage facilities it is seen that 840 (38%) have adequate flush toilet systems, 73 (3%) only partially adequate flush toilet systems and two (1%) with incinerator toilets, leaving 1264 (58%) with privies, or no toilet facilities at all.

Recommendations were prepared for every school requiring improvements, setting forth what was needed. A copy of this was also furnished the State Planning Board. Since then, every assistance possible had been extended to the counties in securing aid from the FERA (Federal Emergency Relief Administration) for labor involved. A second survey of the accomplishments has been started, but the data is still incomplete. It definitely indicates a considerable number of swivel chair officials unwilling to exert themselves, who prefer to respond by pleading a lack of finances. This problem is being met in many counties by a little ingenuity and effort.

Though the State Health Officer has approved summarily closing those schools not complying with sanitary provisions, this step as a general thing does not seen advisable just now….In view of the known shortage of finances some leniency is being granted to permit the installation of facilities with the least possible embarrassment to school authorities.

The State Board of Health should maintain a full time supervisor of sanitation for schools, who is fully informed on water supply installations, plumbing and general construction methods, to advise local school authorities on details of construction which would conform to public health principles and at the same time conserve the funds of the school board as much as possible…."