| Friday, December 19, 2003
"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 et al.
International Journal of Epidemiology
Epi Update Managing Staff:
John Agwunobi, MD, MBA, Secretary, Department of Health
Landis Crockett, MD, MPH, Director, Division of Disease Control
Acting Bureau Chief,
Epi Update Managing Editor
Jaime Forth, Copy Editor/ Writer
| This Week in the News|
►Influenza Investigation at Sarasota Facility Finds Vaccination Rate an Issue
Next week will be a time of celebration for people all over the world. Like many of our readers, staff members at the Bureau of Epidemiology will take time away from work to enjoy the company of friends and families, honor timeless traditions and just relax. We'll return after the New Year with a brand new issue but in the meanwhile, we extend our warmest wishes to all for a happy and memorable holiday. The Editors
|A R T I C L E S|
Matthew R. Laidler, MA, MPH, Florida EIS Fellow, Sarasota County Health Department
Roger Sanderson, MA, RN, Regional Epidemiologist, Bureau of Epidemiology
Jaime Forth, Copy Editor/Writer, Bureau of Epidemiology
Angela Fix, MPH, Respiratory Disease Surveillance Epidemiologist, Melissa Covey, Influenza Surveillance Coordinator
Pete Garner, Surveillance Systems Manager, Bureau of Epidemiology
Caroline Collins, Arbovirus Surveillance Coordinator and Carina Blackmore, DVM, Ph.D., Acting State Public Health Veterinarian, Bureau of Community Environmental Health
The Sarasota County Health Department was informed December 9th of an influenza-like illness (ILI) in a long-term care facility (LTCF) in the county. Ongoing investigation has identified 51 cases of an ILI that have occurred between December 4th and December 16th. Eight of 9 resident cases were laboratory confirmed (PCR) from nasal swabs as infected with influenza A virus, H3N2.
Cases were defined as any LTCF resident or staff that presented with respiratory symptoms in association with fever on or after December 4th, 2003. A total of 51 probable and laboratory confirmed cases occurred between December 4th and 16th. Fourteen of these cases were residents, while thirty-seven were staff.
Laboratory specimens were collected for 9 of the resident cases, 8 of which were positive for influenza A, H3N2. Three of the resident cases were hospitalized as a result of complications from the illness. Two of the laboratory confirmed cases died within one week of illness onset. One of the probable cases also died within days of illness onset, although initial lab results from an area health care provider for this case were negative for influenza A or B. Co-morbidity was likely a contributing factor in mortality for all three cases. Two of the deaths occurred in residents that had not been previously vaccinated for influenza.
Fifty-seven percent (N=45) of residents and twenty-two percent (N=20) of staff were administered the influenza vaccine greater than 30 days prior to the increase in ILI illnesses in the LTCF. Thirty-five percent of residents (N=5) that became ill had previously received the influenza vaccine. Eleven percent of staff that became ill (N= 4) had been previously vaccinated. The relative risk associated with illness in non-vaccinated residents was 2.46 (95% CI= 0.82, 7.92). The relative risk of illness associated with non-vaccination in staff was 2.29 (95% CI= 0.96, 7.24; Fisher?s exact p= 0.031). Figure 1 shows the distribution of cases by illness onset date in the entire LTCF population (residents and staff combined). Figure 2 shows the separate distributions of illnesses by onset date for staff and residents.
Infection control recommendations were made to control the transmission of the virus. Recommendations included isolation of ill residents, restriction of visitation and visitor contact, droplet precautions for attending staff, and vigilance in hand washing and other measures associated with personal hygiene. Prophylaxis was recommended for staff and residents. A small number of remaining influenza vaccine doses were re-offered and administered to consenting residents and staff. A number of infection control practices were in place prior to recommendations.
This investigation represents the first greater than expected increase in ILIs and the first cluster of laboratory confirmed illnesses associated with the influenza virus in Sarasota County in 2003. Mortality associated with the increase in influenza-associated illness is expected in any given year, especially in the elderly and at-risk population; however, it is yet unclear what this cluster of influenza-associated deaths implies for the current influenza season. In the absence of strain typing (laboratory results pending as of December 16th, 2003), the efficacy of the current vaccine and vaccination in this population is unclear. In general, efficacy in the population greater than 65 years of age may be lower than 58%.1
Analysis of data collected in the investigation suggests that vaccination remains the primary factor in preventing greater than expected increases in influenza illnesses in LTCFs. The greater than expected increase in cases in this particular facility began with two previously unvaccinated staff members. From there, virus transmission appears to have continued until 18% (N=14) of the residents and 40% (N=37) of the staff were affected (as of December 15th, 2003). The risk associated with non-vaccination in the staff and resident population suggests that a greater vaccination rate might have been effective in limiting infection and illness. The investigation of these illnesses continues.
►Professional Infection Control Association Annual Meeting to be Held in January 2004
Clifford McDonald, M.D. of the Centers for Disease Control and Prevention will present on Clostridium difficile; William Rutala, PhD, MPH, University of North Carolina will speak about CDC guidelines on disinfection and sterilization in healthcare facilities; Andrew Streifel, MPH, University of Minnesota, will give a presentation on infection control and construction; pertussis outbreak will be addressed by Donna Haiduven, PhD, RN, CIC, of the University of Florida; Dennis Maki, M.D., University of Wisconsin, will discuss intravascular device-related infections; and Sandra Burke, RN, MPH, a health care consultant will speak on JCAHO infection control standards.
A total of 7.8 nursing CEUs will be provided. Laboratory CEUs have been applied for and are pending. For registration and accommodations information, or to find out about vendor arrangements, log on to the local APIC website at www.bapic55.org. Early registration is recommended for this popular event as space is limited.
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Public health practitioners have been aware of this problem for years, but the general public has remained unaware of the dangers of exposure to salmonellosis from reptiles and amphibians. The increase in popularity of these animals as household pets as risen in direct proportion to the number of reptile-related Salmonella cases detected in humans. Although all reptiles and amphibians are potential carriers, frogs and toads specifically are hosts of the disease and have been epidemiologically linked to outbreaks.
To minimize risk of infection, wash hands immediately after contact and thoroughly wash with soap and water objects which have come into contact with reptiles. Households with children under the age of five should not have reptiles inside the home, but if so, they should not be allowed to move freely throughout the living area. Dishes, cages or aquariums should not be washed in bathrooms or in areas where food is prepared.
The MMWR report references a case investigated in Osceola County, Florida in January 2000 in which a child developed fever and diarrhea after exposure to a bearded dragon. The case study was eventually published in the March 8, 2000 edition of Epi Update. To read the article, go to http://www.doh.state.fl.us/disease_ctrl/epi/Epi_Updates/2000.htm.
To read this week's report published by the CDC, go to http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5249a3.htm
Florida influenza-like illness (ILI) activity continues to increase statewide. Fourteen counties are reported as having high ILI% activity for the week ending December 6 (Week 49). Significance testing is not done for these percentages. Of the 18,596 patients seen by the sentinel providers during the week ending December 6, 517 were seen for influenza-like illnesses (overall state ILI activity of 2.78%). The number of specimen submissions and positive laboratory results increased during the week ending December 6. The Influenza A strain H3N2 continues to be the predominant strain circulating throughout Florida. Of the thirty-five specimens received by the state laboratories for influenza isolate testing during Week 49, fourteen were positive for Influenza A (H3N2). The Bureau of Epidemiology continues to encourage the county influenza coordinators to contact their sentinel providers to promote submission of laboratory specimens for subtyping. The best way to prevent the flu is to get vaccinated. However, in the absence of vaccine there are other ways to protect yourself and your family from the flu. Good heath habits such as avoiding close contact with those who are ill, staying home whenever possible if you are sick, covering your mouth and nose with a tissue when you sneeze or cough, washing your hands regularly, and avoiding touching your mouth, eyes and nose after touching items that may be contaminated with germs can help prevent the spread of influenza to you and those around you.
Florida Influenza-Like Illness (ILI) Summary
Seventy sentinels from 64 public clinics and private offices submitted reports for 27 counties during the week ending December 6, 2003 (Week 49). Counties with the highest percentage of patients with ILI were Leon (2.50%, 2 of 2 sentinel locations reporting); Okaloosa (2.51%, 2 of 5); Duval (2.56%, 5 of 9); Alachua (2.89%, 1 of 2); Seminole (2.91%, 2 of 5); Orange (4.19%, 6 of 9); Indian River (4.46%, 2 of 3); Lake (4.71%, 1 of 2); Pinellas (5.65%, 5 of 8); Broward (6.68%, 6 of 7); Polk (7.62%, 4 of 4); Osceola (7.99%, 2 of 2); Palm Beach (9.02%, 5 of 5); and Pasco (9.09%, 1 of 1). Nine counties reported a low percentage of patients with ILI, and 4 counties reported no cases of ILI. A breakdown of ILI% reported for weeks ending December 6, 2003 by county is listed in Table 1.
Laboratory Specimen Testing in Florida
Fourteen of the 35 specimens received by the Jacksonville Central and Tampa Branch laboratories for influenza isolate testing during the week ending December 6, 2003 (Week 49) were found positive for influenza A (H3N2). These viruses came from Broward (1), Duval (4), Hillsborough (3), Indian River (2), Leon (1), Miami-Dade (1), Okaloosa (1), and St. Johns (1) counties.
From September 28, 2003 to December 6, 2003, the Florida laboratories tested a total of 137 specimens and found 35 positive for influenza A (H3N2). The remaining specimens were negative for influenza. Table 2 details isolates found since September 28, 2003 by county.
Rapid Testing Performed by Private Laboratories in Florida
Reports received from one clinic, three hospitals and one private laboratory since September 28, 2003 are summarized in Table 3.
National Influenza Surveillance
This section summarizes the weekly influenza report from the Centers for Disease Control and Prevention. More detailed information can be found at their website: http://www.cdc.gov/ncidod/diseases/flu/weekly.htm and at http://www.cdc.gov/ncidod/diseases/flu/vacfacts.htm#01
Influenza-Like Illness Report for the Week ending December 6, 2003
The proportion of patient visits to sentinel physicians for influenza-like illness (ILI) was 5.1% nationwide. This is above the national baseline of 2.5%. The percentage of patient visits for ILI increased in all regions except the West South Central region, where it has decreased (7.0% for week 49 compared with 11.5% for week 48). On a regional level, the percentage of visits for ILI was highest in the Pacific and Mountain regions (7.76%), followed by the West South Central (7.0%), East South Central (5.3%), West North Central (4.9%), and South Atlantic (4.4%) regions. All other regions were below 4%. Due to wide variability in regional level data, it is not appropriate to apply the national baseline to regional level data. National percentage and regional percentages of patient visits for ILI are weighted on the basis of state population.
Antigenic Characterization: CDC has antigenically characterized 212 influenza A (H3N2) viruses submitted by U.S. laboratories since October 1. Of the 212 A (H3N2) viruses tested, 54 (25%) were similar antigenically to the vaccine strain A/Panama/2007/99 (H3N2), and 158 (75%) were similar to the drift variant, A/Fujian/411/2002 (H3N2). Of the seven influenza A (H3N2) viruses submitted to the CDC from Florida since mid-October, 3 were A/Fujian/411/2002 (H3N2)-like and the remaining were A/Panama/2007/99-like (H3N2)-like. The CDC has also antigenically characterized one influenza A(H1N1) virus that was similar to the vaccine strain A/New Caledonia/20/99.
Influenza drift variant, A/Fujian/411/2002 (H3N2), found in the United States and Europe
The influenza A drift variant, A/Fujian/411/2002 (H3N2) predominated the Australian and New Zealand outbreaks that peaked in mid-to-late August 2003, and has been detected in many countries in the Northern Hemisphere, including the United States. The CDC expects the current U.S. vaccine will offer some protective immunity against the A/Fujian/411/2002-like viruses because these viruses are related to the vaccine strain, A/Panama/2007/99. Antibodies produced against the vaccine virus cross-react with A/Fujian/411/2002-like viruses, but at a lower level.
U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) Laboratories Report
Since September 28, 2003, 6,751 (27.1%) of the 24,906 specimens tested for influenza viruses were positive. One thousand two hundred fifty-four influenza A (H3N2) viruses, one influenza (H1) virus and 135 influenza B viruses have been identified. Of the specimens submitted to date, 2,419 (35.8%) were reported from the West South Central region and 2,278 (33.7%) were from the Mountain region.
Weekly ratios rather than proportions are presented in the 2003-2004 Summary By Region because specimens reported positive for influenza virus each week may include specimens submitted for testing during an earlier week.
122 US Cities Vital Statistics Mortality Report
The percentage of all deaths due to pneumonia and influenza was 7.0%. This percentage is below the epidemic threshold of 7.6% for the week ending December 6, 2003.
International Influenza Activity -
World Health Organization Communicable Disease Surveillance and Response.
WHO issued Update 3 on December 10, 2003 in which significant increased in influenza activity associated with influenza A (H3N2) in some countries in the northern hemisphere is reported. Countries in Asia most frequently report influenza B viruses; sporadic cases of influenza B have been found in Europe and North America. An influenza A (H1) outbreak that had begun in Iceland during early October had ended by mid-November. For more information about the WHO Communicable Disease Surveillance and Response Updates, please visit their website at http://www.who.int/csr/en/ .
FluWatch Report from the Canadian Centre for Infectious Disease Prevention and Control
For the week ending November 15, 2003, widespread influenza activity was reported in all regions in Saskatchewan and 1 region in Ontario, localized influenza activity was reported in all regions of the North West Territories, 2 regions of Nunavut, 1 region of Alberta, Manitoba and Nova Scotia, and sporadic influenza activity was reported Alberta, Manitoba, Nova Scotia, Nunavut, Quebec and the Yukon.
Four Influenza outbreaks were reporting in schools in Nova Scotia (3) and Alberta (1); long-term care facilities in Alberta (2), British Columbia (1), Manitoba (1), Ontario (2), and Saskatchewan (2); and a hospital in British Columbia. Influenza related deaths were reported in Ontario (2 seniors, and a 10-year-old child with co-morbidities).
For more information about the FluWatch report, please visit their website at http://www.hc-sc.gc.ca/pphb-dgspsp/fluwatch/index.html
Report from the European Influenza Surveillance Scheme (EISS)
Of the 22 European countries that are members of the EISS, widespread influenza activity was reported in Belgium, England, France, Norway, Portugal, Scotland and Spain; Switzerland reported regional activity; and Denmark, Ireland, Luxembourg, the Netherlands, Northern Ireland, Romania and Sweden reported local outbreaks for the week ending December 6, 2003 (Week 49). All other countries in Europe reported sporadic or no activity.
Strain characterization: Based on data available for the 145 viruses isolated up to week 49, 88.3% (128) were A/Fujian/411/2002 (H3N2)-like, 6.2% were A/Moscow/10/99 (H3N2)-like, 3.5% (5) were A/New Caledonia/20/99 (H1N1)-like, 1.4% were B/Hong Kong/330/2001-like. A B/Sichuan/379/99-like virus was isolated in Germany is reported to be a sporadic case that represents less than 0.7% of all strain characterizations, and the EISS will carefully monitor B/Sichuan-like isolates in Europe.
Season Summary: Early influenza activity in Spain, Portugal, the United Kingdom and Ireland has slowed down or declined, and has increased in most other countries in Europe. Seasonal influenza activity has begun to gradually move across Europe but has not reached a number of countries, most of which are in the eastern part of Europe. For more information about the EISS report, please visit their website at http://dev.eiss.org/cgi-files/bulletin_v2.cgi.
WHO Collaborating Centre for Reference and Research on Influenza, Melbourne Australia
Australia?s winter months are from May to October. One of Australia?s biggest influenza seasons since 1998 peaked from mid to late August 2003, and by October cases of influenza had generally subsided. Influenza A (H3) viruses were cited as the primary cause of outbreaks, with little A (H1) or B viruses isolated during the season. For more information about Australian influenza, please visit the Melbourne, Australia Branch website at http://www.influenzacentre.org/ (specific article can be found at http://www.influenzacentre.org/flunews.htm#subsiding).
2002-2003 Influenza Surveillance Summaries