Human Cases of H7N7 Infection in The Netherlands: As of April 25, 2003, the National Influenza Center in The Netherlands reported that 83 confirmed cases of human H7N7 influenza virus infections had occurred among poultry workers and their families since the H7N7 outbreak began in chickens at the end of February 2003. The vast majority (79) of these people had conjunctivitis, and 6 of those with conjunctivitis also reported influenza-like illness (ILI) symptoms (e.g., fever, cough, muscle aches). One person had ILI only (no conjunctivitis) and 2 persons had mild illness that could not be classified as ILI or conjunctivitis. In addition, one individual, a 57-year-old veterinarian who visited one of the affected farms in early April, died on April 17 of acute respiratory distress syndrome (ARDS) and related complications from H7N7 infection. Dutch authorities have reported evidence of possible transmission of H7N7 influenza from 2 poultry workers to 3 family members. All 3 family members had conjunctivitis and one also had ILI.

Public Health Monitoring: CDC is in communication with public health officials in The Netherlands and the World Health Organization (WHO) regarding the recent human cases of influenza A (H7N7) illness in The Netherlands and will continue to monitor the situation. CDC has begun production of a reagent kit that would allow laboratories to identify influenza A (H7N7) viruses. To enhance timely detection of any additional human influenza cases due to these viruses, WHO recommends that affected countries conduct enhanced surveillance for influenza among humans and animals and conduct studies to better understand possible transmission patterns. CDC and WHO have issued no restrictions on travel to The Netherlands. Additional information from WHO can be found at http://www.who.int/csr/don/2003_04_24/en/.

Influenza in the United States: Influenza activity in the United States is at low levels. Influenza A (H1N1), A (H1N2), A (H3N2), and influenza B viruses have been identified in the United States during the 2002-03 season and have been well matched by the current influenza vaccine. The current vaccine does not protect against infection with the influenza A (H7N7) virus. U.S. residents who are traveling outside the United States should consult their physician for advice about whether they should be vaccinated against influenza and about the use of influenza antiviral medications.

Introduction:  On February 10, 2003 the Pasco County Health Department was notified by the infection control nurse at a local nursing home that several residents and staff at the facility were exhibiting gastrointestinal symptoms of nausea, vomiting and diarrhea, with onset times averaging one to two days. Twenty-six residents and 17 staff members were affected. Of the ill staff members, 10 CNAs, four nurses, and three non-medical employees were affected.

Methods:  Strict hand washing procedures, restriction of ill residents to their rooms and in-service training for staff were implemented immediately. All sick employees were restricted to the west wing. There were no reports of illness affecting residents in the east wing. The door separating the two wings was locked. A notice was posted informing all visitors of the requirement to check in at the nurses station, where they were notified of the outbreak and of the need to wash hands before and after visiting with residents.

An investigation of the facility was performed on February 12 by members of the Pasco County Health Department and the Bureau of Environmental Epidemiology. A line listing of all ill residents and staff was obtained. Information on patient food history and names of residents on tube feeding was provided. Eleven vomitus and stool samples from residents and staff were submitted for viral testing to the Tampa Branch of the Bureau of Laboratories. The investigators toured the west wing of the facility.

Results:  Of the 11 specimens examined, only one tested positive for norovirus serogroup G2. The remaining 10 specimens were negative, with no additional testing performed. A review of the line listing showed staff and residents exhibited like symptoms of nausea, vomiting, diarrhea and abdominal pain. Duration of the illness was also similar, lasting from 24-28 hours. Before onset, staff movement between east and west wings of the facility was uninhibited. There was no illness among residents in the east wing. A tour of the west wing showed all rooms were well maintained and proper medical procedures observed.

The food services investigation showed the kitchen area to be well maintained and organized. The last quarterly inspection was November 2002 with no major violations noted. The facility receives its water from a public source. Of the ill staff members, only one was a food service worker, with the individual often interacting among residents during mealtime.

Conclusions:  Upon review of the data, it was concluded that the most likely method of transmission was person-to-person. Cases reported varying onset times spaced over a five-day period. Only one specimen tested positive for norovirus but based on symptoms, incubation periods and duration, there is a high probability that the other cases were also caused by the same pathogen. The fact that the virus was contained to the west wing could be attributed to good hygiene control by facility staff.

Vancomycin resistant S. aureus is rare and its emergence underscores the need for a collaborative effort between the county health departments and the state health office to prevent the spread of this and other antimicrobial-resistant microorganisms and control the use of anti-microbial drugs in health-care settings.

In 1997, the Healthcare Infection Control Practices Advisory Committee published guidelines for the prevention and control of staphylococcal infection associated with reduced susceptibility to vancomycin (2); plans to contain vancomycin resistant S. aureus on the basis of CDC recommendations have been established in Florida. In the health-care setting, a patient with colonized with potentially resistant strains of S. aureus should be placed in a private room and have dedicated patient-care items. Health-care workers providing care to such patients should follow contact precautions (i.e., wearing gowns, masks, and gloves and using antibacterial soap for hand washing).

Any suspected resistant S. aureus organism should be tested for resistance to vancomycin using a MIC method and confirmed by one of the Florida State Branch Laboratories. Efforts should be made to encourage all clinical microbiology laboratories outside the state branch lab system to retain and report specimens with reduced susceptibility to vancomycin.

S. aureus with evidence of either intermediate or complete resistance to vancomycin (not MRSA) is reportable in Florida. The isolation of S. aureus with confirmed or presumptive vancomycin resistance should be followed up and the Bureau of Epidemiology should be notified by the local county health department immediately. All suspect cases should be followed up with the reporting provider or laboratory to confirm and possibly repeat susceptibility testing on the patient’s isolate.

1. Hiramatsu K, Hanaki H, Ino T, Yabuta K, Oguri T, Tenover FC. Methicillin-resistant Staphylococcus aureus clinical strain with reduced vancomycin susceptibility. J Antimicrob Chemother 1997;40:135--6.

National report:* During week 16, twelve isolates (7 influenza A and 5 influenza B viruses) were made from 600 specimens tested by the World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories this week. The proportion of deaths attributed to pneumonia and influenza as reported by the vital statistics offices of 122 U.S. cities was 7.6% during week 16. This percentage is below the epidemic threshold of 7.9% for this time. The proportion of patient visits to sentinel physicians for influenza-like illness (ILI) was 1% nationwide. The State and Territorial Epidemiologists in Alaska reported widespread influenza activity. Four states (Idaho, Montana, North Dakota, and Ohio) reported regional activity, and 32 states and New York City reported sporadic influenza activity. Nine states reported no influenza activity. During the past 3 weeks (weeks 14-16), 22.7% of the specimens tested for influenza in the New England region were positive, between 6.2% and 10.3% of the specimens tested for influenza in the Pacific, Mountain, West North Central, and East North Central regions were positive, and less than 3.0% of the specimens tested for influenza in the East South Central, West South Central, Mid-Atlantic, and South Atlantic regions were positive. However, during the past 3 weeks (weeks 14-16), influenza A viruses were reported more frequently than influenza B viruses in all nine surveillance regions.

The Netherlands reported in April the first fatal human case of influenza A (H7N7).

An outbreak of highly pathogenic avian influenza A (H7N7 HPAI) in chickens began during February 2003 in The Netherlands and, despite control measures (restricting transport and culling), has spread to Belgium and Germany, to swine herds in The Netherlands, and humans. Of the 83 confirmed cases of human H7N7 in the Netherlands, 79 exhibited conjunctivitis and 13 had mild ILI. Possible human-to-human transmission was suggested when three family members of two poultry workers fell ill with a minor respiratory disease. The WHO Influenza Collaborating Centers are to begin production of a reagent kit to identify H7N7 viruses. More information about this outbreak of H7N7 HPAI can be found at: http://www.who.int/csr/don/2003_04_24/en/

Asia. An avian flu virus strain, influenza A (H5N1), was recovered from two influenza cases in Hong Kong earlier this year. CDC has issued recommendations on increased influenza surveillance in the United States. Of particular importance is consideration of influenza cultures on patients with recent travel histories to Asia who are hospitalized with unexplained pneumonia, acute respiratory distress syndrome or severe respiratory illness.

* Reporting is incomplete for this week. Numbers may change as more reports are received.

Human: No cases of arboviral meningo-encephalitis were reported this week.

Gilchrist County is under Medical Alert for EEE virus.

Sentinel Chickens: Two seroconversions to EEE virus were confirmed in Alachua County. This week, 638 samples were tested from 17 counties.

Bird Mortality: No dead birds were reported positive for arbovirus this week.

Equine*: Three EEE virus infections in horses were reported from Alachua, Hernando and Levy counties.

Wild and Captive Birds: See http://www.pherec.org/DECS Arbovirus Ecology to view database.

Mosquito Pools: No mosquito pools were reported positive for WN or EEE virus this week.

1. Report dead birds to www.wildflorida.org/bird/. From that site, you can link to online bird identification sites. There is value in the information submitted even if the bird is not tested, especially for those counties which don't have sentinel chickens or who have sites situated sparsely in the county.

2. The DOH Lab in Tampa will test anything that's shipped in good condition. Instructions for submission of dead birds are found at: http://www9.myflorida.com/disease_ctrl/epi/htopics/arbo/index.htm Select "How do I report?" then choose "Protocol for Collecting and Shipping Bird Carcasses" under "Dead Birds" subtopic.

3. If local agency must cut back on bird submissions, consider only sending crows and jays.

4. If personnel are not able to offer pick-up service, have a drop off station and provide the caller with clear handling instructions. A county may modify their testing approach depending on the availability of other surveillance systems in the county.

1. Human Surveillance: No activity has been reported for WN, SLE, EEE or Dengue.

Positive samples from 31 horses in 17 counties, 2 dead birds in 2 counties, and 10 sentinel chickens in 6 counties were received. To date, 22 of Florida’s 67 counties have reported EEE virus activity. Date of disease onset (horses), date of death (birds) and date of first known positive bleed (sentinels) is shown in parentheses, unless otherwise indicated.
Alachua: 4 horses (3/25, 3/31, 4/13, euthanized 4/15), 2 sentinel chickens (4/14, 4/15)
Baker: 2 horses (3/28, 3/29)
Bradford: 3 horses (3/14, 3/25, unkn)
Clay: 1 horse (4/2)
Flagler: 1 sentinel chicken (4/7)
Gilchrist: 4 horses (3/24, 3/25, 3/27, 4/7)
Hamilton: 1 dead bird (cardinal 4/3)
Hernando: 1 horse (euthanized 4/15)
Hillsborough: 2 sentinel chickens (3/17, 3/31
Jefferson: 1 horse (4/2)
Lafayette: 1 horse (3/12)
Lake: 1 horse (3/12)
Levy: 4 horses (3/15, 3/20, 4/3, euthanized 4/10)
Marion: 3 horses (3/19, 3/31, 4/1)
Orange: 2 sentinel chickens (3/27, 3/27)
Osceola: 1 horse (4/11)
Pinellas: 1 sentinel chicken (3/31)
Polk: 1 horse (3/21)
Putnam: 1 horse (3/22
St. Johns: 1 horse (3/26)
Sumter: 1 horse (3/24)
Suwannee: 1 dead bird (emu 3/24)
Volusia: 1 horse (n/a)
Walton: 2 sentinel chickens (3/24, 3/24
* Equine cases are determined by the Department of Agriculture and Consumer Services.

For more information please see the DOH website at http://www.doh.state.fl.us/disease_ctrl/epi/htopics/arbo/index.htm

Acknowledgements/data sources: county health departments, Department of Health Laboratories, Department of Agriculture and Consumer Services, mosquito control agencies, Florida Fish and Wildlife Conservation Commission, medical providers and veterinarians.

The Disease Outbreak Information Hotline offers updates on medical alert status and surveillance at 888.880.5782. Florida is currently at Level I in the Arbovirus Response Plan. DOH press releases can be viewed at http://apps3.doh.state.fl.us/IRM/PressReleaseSearch/cfm.

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