A R T I C L E S

Meghan M. Weems, MPH, Epidemiology Intelligence Service, Palm Beach County and Savita Kumar, MD, MSPH, Epidemiologist, Palm Beach County Health Department

Robyn Kay, MPH, Epidemiology Intelligence Service, Duval County, Bureau of Epidemiology

Dr. Fermin Leguen, Senior Physician, Miami-Dade County Health Department, Mary Jo Trepka, MD, MSPH, Zhang Gouyan, MD, MPH, Marie Etienne, RN, Office of Epidemiology & Disease Control

Kathryn S. Teates, MPH, Communicable Disease Surveillance & Reporting Manager, Bureau of Epidemiology

Pete Garner, Surveillance Systems Section Administrator, Bureau of Epidemiology

Caroline Collins, Arbovirus Surveillance Coordinator and Carina Blackmore, DMV, Ph.D., Acting State Public Health Veterinarian, Bureau of Community Environmental Health

Please note that numbers are subject to change with confirmatory information

►Locally Acquired Malaria "Probable" in Palm Beach County 

Background

Malaria is a disease caused by one of four species of protozoan parasites (Plasmodium) spread by the Anopheles mosquito. Symptoms include headache, aching in the bones, anorexia, fever and chills in a repeating cycle. The incubation period can be as short as seven days or as long as several months. Although malaria disappeared as a significant problem in the U.S. by the mid-1950’s, it is still one of the most important communicable diseases in the world. Palm Beach County sees an average of 12 malaria cases per year, but most have a history of international travel to a malarious area. The Palm Beach County Health Department (PBCHD) was alerted on 7/25/03 of two cases of malaria in a local hospital in Palm Beach County.

Case investigation

Case 1. On July 24^th a 46-year-old man residing in central Palm Beach County was admitted to a local hospital with a history of fever, chills, anorexia, headache and vomiting. His admitting diagnosis was pneumonia. On 7/25/03, a thick blood smear slide showed Plasmodium vivax parasites. Those findings were confirmed at the state laboratory in Miami and at CDC. The patient had no recent history of travel, blood transfusion, organ transplant, or IV drug use. He did, however, indicate that he spends time outdoors on a regular basis, especially at dusk. He was treated with antibiotics, quinine and primaquin and discharged from the hospital on 7/27/03.

Case 2. On July 24^th a 36-year-old man residing in central Palm Beach County was admitted to the same local hospital complaining of fever, headache, and vomiting. His admitting diagnosis was non-erosive gastritis. His thick blood smear slide showed malaria parasites on 7/25/02. His species was also identified as P. vivax. This patient had returned from the Bahamas on July 2 but it was decided that this travel was not his likely exposure due to the fact that the Bahamas is not known as a malarious area. He had no history of blood transfusion, organ transplant or IV drug use. He was treated with antibiotics, quinine and primaquin and discharged on 7/27/03.

The two case patients live four houses apart on the same street in a neighborhood in central Palm Beach County. They do not report spending much time together, but both attended a block party on their street over the July 4^th weekend. The party lasted late into the evening. Both their careers led them to spend a majority of time outdoors as construction worker and plumber. 

Active Case Detection

An investigative team from PBCHD went on a neighborhood outreach on 7/27/03, the Sunday after the case patients were announced to the public. They operated in a four-block radius going door-to-door, handing out fact sheets and administering surveys. The survey’s aim was to identify active cases by asking about current mosquito exposure, symptoms, and travel history. The team visited over 50 houses. If the homeowner was not home, information was left on the premises. The team identified three people who had either matching risk factors or symptoms. None of these suspect cases turned out to be cases of malaria. Active case detection was hampered by the presence of TV cameras and reporters who may have intimidated neighborhood residents, preventing them from being interviewed by the investigators.

All local hospitals were notified of the two cases. They were asked to test suspect cases for malaria and report results to the PBCHD.  

A press conference was held on 7/27/03 to inform residents of the situation and how to seek medical attention if needed. Ways to avoid mosquito bites were also discussed during the press conference. A separate press conference was held for Spanish-speaking media.

An alert for malaria was announced for the two-mile radius surrounding the affected neighborhood. The Emergency Operations Center of PBC instituted “reverse 911,” and over 35,000 area households were called. Residents within a nine-square-mile radius heard a recorded message informing them of the malaria cases and how to avoid mosquito bites.  

A fax was sent to all area physicians within six zip code areas and infection control practitioners at the 14 hospitals in Palm Beach County, asking them to perform a "lookback" for cases of malaria or similar constellation of symptoms as malaria since June 1, 2003. The same fax was sent to all infectious disease specialists in the county.

Environmental and Entomologic Investigation

Palm Beach County Mosquito Control performed mosquito trapping on two occasions at two sites in the affected neighborhood. The first trapping yielded a small population (4/10 trapped) of Anopheles quadrimaculatus mosquitoes. The second trapping yielded none. Those mosquitoes are being sent to CDC for further testing. No standing water or larvae were found at either case’s home. Mosquito spraying was performed three times in a nine-square mile area around the neighborhood.  

Conclusion

The PBCHD is still searching for cases and trying to identify a person or persons with malaria that might have been the source of the mosquito infection. Gametocytemic persons (those with active malaria parasites in their blood) are present in the United States and can serve as reservoirs of infection. Palm Beach County is a haven for visitors who come from all over the world including malarious areas. It is possible that a person could have come from abroad with malaria and has treated symptoms with home remedies or inadequate treatment. The individual may not be fully treated and is still circulating parasites, allowing mosquitoes to become infected when they feed, thus spreading malaria into the community. Relapse of P. vivax can occur up to four years after primary infection. This is not likely a case of airport/baggage malaria since the airport is much farther from the neighborhood than the two miles that most mosquitoes can travel.

To protect oneself from mosquito borne illnesses, it is important to remember the D’s:

• D- Dusk-Dawn - Avoid being outdoors when mosquitoes are most active.

• D- Dress - Cover skin with protective clothing.

• D- DEET - Protect bare skin with mosquito repellent containing DEET.

• D- Drain - Empty containers holding stagnant water in which mosquitoes breed.

International travelers to malarious areas should begin anti-malarial prophylaxis at least one week before travel and two weeks after their return to the United States.

Acknowledgements

Many thanks to the staff of the Bureau of Epidemiology and Environmental Health, Miami State Laboratory, and Palm Beach County Health Department Epidemiology and Environmental Health for their help in this investigation.

References

CDC. Probable locally acquired mosquito-transmitted Plasmodium vivax infection---Suffolk County, New York, 1999.MMWR 2000; 49 (22); 495-8

CDC. Probably locally acquired mosquito-transmitted Plasmodium vivax infection---Georgia, 1996. MMWR 1997; 46: 264-7

CDC. Local transmission of Plasmodium vivax malaria--- Virginia, 2002. MMWR 2002; 51 (41); 921-923 

►Vibrio Outbreak Discovered in Duval County 

Introduction

On June 23, 2003, the Duval County Health Department (DCHD) Epidemiology Division received a referral from the State of Florida Regional Epidemiologist for Food and Waterborne Diseases regarding three people who had purchased garlic crabs, two of whom became ill after eating the garlic crabs on June 21. On June 24 an additional person contacted the DCHD to report becoming ill after consuming garlic crabs on June 21 from the same seafood market.  

Methods

Three of the four individuals reported illness after consuming garlic crabs from the seafood market. A case was defined as any person consuming garlic crabs at this seafood market between June 21 and June 22, and exhibiting symptoms of diarrhea, vomiting, and cramps. A DCHD epidemiology nurse conducted a case history for each person. Common symptoms included: diarrhea, nausea, vomiting, fever/chills, and cramps. None of the individuals sought medical attention from a health care provider or were hospitalized. The onset of symptoms ranged from 2 to 12 hours after eating the garlic crabs, with the duration of illness ranging from one to seven days. All of the case patients purchased the garlic crabs as takeout, and ate them within an hour of purchase.

No other common exposures existed between the three cases. No additional complaints by other persons were made to DCHD or DBPR (Department of Business and Professional Regulation).

A leftover food sample of the garlic crab was provided by one of the ill persons and was submitted to the state lab on June 24 by the Regional Foodborne and Waterborne Disease Epidemiologist. Stool specimens from two of the ill persons were submitted on June 24 and June 26 for bacteria, enterovirus, norovirus, ova, and parasite analysis.

On June 24, 2003, the DPBR inspected the facility providing the garlic crab meals and reviewed food handing practices. In addition, the Regional Epidemiologist for Foodborne and Waterborne Diseases and the Florida Epidemic Intelligence Service officer from DCHD conducted an environmental epidemiological investigation to determine the source of the pathogens, mode of transmission, proliferation, and exposure. The seafood market sells packaged meals of crabs, shrimp, corn, and potatoes.

Multiple cross contamination violations were observed in the facility including raw and cooked food products placed next to and on top of each other in the display case. Cooked food products were exposed to raw food products through contaminated food preparation and handling surfaces, improper hand glove use, and unsuitable storage of cooked food products in perforated metal containers on the floor.  

Temperature abuse was another problem. The walk-in storage cooler in the back room was set at 50° F. Cooked crabs were inadequately cooled to 41° F prior to packaging in styrofoam boxes. Cooked crabs were stored in a display case that was unable to maintain a temperature of 41° F.     

Results

Stool specimens were obtained from two of the ill individuals. Stool samples tested negative for parasites and bacteria. The food sample yielded the following results: Standard plate count/gm: 2,200,000/gm, Fecal Coliform MPN/gm: 40/gm, Vibrio parahaemolyticus, and Vibrio alginolyticus.

The DPBR issued two warnings and re-inspected the facility on July 10, 2003. In addition, the Regional Epidemiologist for Foodborne and Waterborne diseases, the Reportable Disease Program Manager from DCHD, the Florida Epidemic Intelligence Service Officer from DCHD, and the sanitarian from DPBR revisited the facility on July 15, 2003 to discuss food handling and sanitation practices of the seafood market. The owner was educated on food handling, temperature controls, and ways to minimize cross contamination in order to ensure a safe food product is sold to patrons.

Discussion

Vibrio parahaemolyticus is a naturally occurring bacterial organism that inhabits coastal and estuarine waters. Vibrio parahaemolyticus is commonly associated with the consumption of raw or undercooked shellfish, resulting in gastrointestinal illness between 2 and 48 hours after ingestion. There are two ways to prevent Vibrio parahaemolyticus infection:

• Use proper food preparation and handling practices to prevent cross contamination between raw and cooked food products

• Maintain proper refrigeration of shellfish to inhibit further bacterial growth.

Conclusion/Recommendations

This was an outbreak of Vibrio parahaemolyticus by consumption of garlic crabs. Multiple cross contamination violations and temperature abuse by the seafood market led to this outbreak. 

Educating food handlers on the proper ways to store, prepare, cook, and distribute food is key in preventing foodborne outbreaks. It is therefore extremely important to continue to educate and monitor those in the restaurant business on proper food safety practices.

The following recommendations were made to the seafood market owner by the epidemiologists:

• Raw and cooked foods need to be stored and prepared separately

• Educate food handlers on proper cross contamination prevention

• Replace deep storage trays with shallow pans to allow crabs to cool quickly prior to packaging

• Maintain proper refrigeration 

• Ensure proper temperature controls through frequent monitoring and recording.    

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► Miami-Dade Survey Shows WNV Awareness Lacking - Current Knowledge, Practices and Attitudes of Miami-Dade Residents about West Nile Virus Disease and its Prevention      

West Nile virus (WNV) is an arbovirus that affects many animal species, including humans.  In most areas, WNV has a mosquito-bird cycle. Migrating birds are believed to play an important role in transferring the virus over long distances. WNV activity has been identified in 42 states and the District of Columbia, with more than 3000 human cases reported during 2002. Miami-Dade County has a diverse population characterized by a high influx of immigrants from Latin America and the Caribbean, as well as other areas of the world who may not share the same level of knowledge, attitudes, and practices related to the prevention of WNV and other arboviral infections. There are no previous studies describing the level of knowledge, attitudes, and practices related to the prevention of WNV and other arboviral infections among Miami-Dade residents.

Methods

In the month of March 2003, Miami-Dade County Health Department conducted a survey among 451 Miami-Dade County residents aged 18 years and older. 

The survey was conducted by computer-assisted telephone interviewing using Computers for Marketing Corporation’s computer-assisted telephone interviewing software package.

Households were selected randomly from all telephone-equipped dwelling units in Miami-Dade County.

One eligible respondent was selected at random from each household included in the survey.

A survey instrument with versions in both English and Spanish was used to collect data for this project.

The survey collected data on knowledge, attitudes and practices related to West Nile virus and other arboviruses.

Results

Seventy-seven percent of respondents reported having heard about WNV in the past, 40% identified fever as a symptom related to WNV, 21% reported not knowing what the symptoms of WNV are. Mosquitoes were identified as a WNV vector by 77% of respondents; 20% also associated mosquitoes with HIV transmission.

Fifty-three percent of respondents keep mosquito repellents at home. Fifty-seven percent of those respondents with history of recent travel reported using mosquito repellents during the trip.

Fifty-one percent of respondents identified the television as their source of WNV and mosquito-related information. Only 2.7% mentioned health department’s documents as their source of information.

Compliance with personal protection against mosquito bites was as follows: 47% of respondents reported use of repellents while outdoors, 8% reported use of screens in doors and windows, 14% use of long-sleeves shirts and long pants while outdoors, and 18% avoidance of outdoor activities after dusk or before dawn. Twenty-two percent of respondents did not think that there was a serious risk of WNV infection in the community, but 37% thought it was as extremely serious. Infants (37%) and persons 50 years of age and older (41%) were identified as those with the highest risk of developing a severe illness due to WNV. 

Conclusion 

Miami-Dade County Health Department should implement an educational intervention among its residents to encourage the use of personal protective measures against mosquito bites.  

The development of partnerships with local media, especially Miami area TV stations will be of paramount importance to the dissemination of educational information about WNV and other arboviral diseases among Miami-Dade residents.

Miami-Dade County Health Department should identify specific educational needs related to arboviral diseases among communities with a higher risk of exposure to mosquito bites due to travel or cultural issues.

               Figure 1.  Identification of symptoms associated with WNV.                                       Miami-Dade County residents, 2003        

Acknowledgments

We would like to extend our appreciation to all staff members of the Office of Epidemiology and Disease Control, Miami-Dade County Health Department for their outstanding support and participation on multiples activities related to the implementation of this project and the surveillance and control of arboviral diseases in Miami-Dade County.   

The full text of this article, including complete charts and graphs, can be accessed by clicking the link below:

Miami Dade WNV Survey

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► Merlin Development Assessment Scheduled

The Merlin Development Team will be conducting a series of meetings to discuss changes to the system by assessing different areas of the application. All Merlin users will be included in this assessment and will be encouraged to give feedback by email, survey or by participating in a conference call. Existing change controls will automatically be included in the assessment. To keep the assessment process more organized, the system has been divided into the following sections: 

August 15^th                   Personal Profile, Basic Case Information, Unattached and  Case Related Laboratory Results

August 27^th                   Task List and Electronic Laboratory Results and Processing

September 4^th                Help Section, Home Page and Resources

September 12^th                   Reports 

Although not covered by the four areas above, comments for the lead poisoning prevention module, perinatal hepatitis B prevention module, rabies module, extended data and any other section are needed as well. 

There will be two conference calls held for input on Thursday, August 21^st at 2:00 p.m. EST and Wednesday, September 10^th at 10:00 a.m. EST. Each call will cover different sections of the system and will be announced in the Epi Update, by email and on the bi-weekly CHD conference call. Those not able to attend the conference call should email comments to the Merlin Helpdesk indicating the assessment in the subject line of the email.

The completed assessment and recommended changes will be published in summary form in the Epi Update.

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► This Week on EpiCom

To stay up-to-date on disease outbreaks around the state and, more importantly, in your own area, you need EpiCom, an easy forum for communication among county health departments, hospitals and the Florida Department of Health. Remember to log on regularly. If you haven't viewed the site this week, these are just a few of the items you've missed learning about firsthand: 

• Two cases of probable locally-acquired malaria in Palm Beach County

• A confirmed case of Campylobacter jejuni in Collier County

• Further developments regarding ILI outbreaks at two correctional institutions

• A training review held for CHD personnel in Martin County

For further information concerning this program, send an email to EpiCom_Administrator@doh.state.fl.us. To view EpiCom, log on to https://www.epicomfl.net/.

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► Pediatric Preparedness for Disasters

The American Academy of Pediatrics has recommended that first responders to emergency and disaster scenes should:

1. Be trained to use pediatric-specific triage systems such as JumpSTART Pediatric Multiple Casualty Incident Systems. 

2. Be equipped with pediatric specific equipment and medications.

3. Incorporate the Pediatric Family Readiness Kit in the current Family Readiness Kit (available through http://www.aap.org/family/frk/frkit.htm).

Furthermore, it recommends:

1. That shelters should be capable of providing child-appropriate nutrition, sleeping arrangements and recreation activities.

2. That disaster drills should be held in every school, every year.

3. That the mental health infrastructure be required to meet the needs of vulnerable children.

Particularly in the case of bioterrorism, it is important to remember that children are more vulnerable to aerosolized agents than adults because they take more breaths per minute than adults; and since some agents, such as chlorine, are heavier than air, they accumulate closer to the ground, endangering more children than adults. In addition, because their skin is thinner, they may be more susceptible to skin-penetrating agents or toxic agents that cause vomiting and diarrhea. Last, toddlers are not able to flee an attack site as quickly as adults, placing them at higher risk of exposure. These facts and other relevant information can accessed at the AAP web site at http://www/aap.org/terrorism.index.html

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► CDC Broadcasts Immunization Update 2003

The Centers for Disease Control and Prevention will air a live broadcast to present information on immunization issues on August 21 from 9:00 until 11: 30 a.m. EDT.  The broadcast will highlight recommendations for use of the new live attenuated intranasal vaccine, pneumococcal conjugate vaccine, hepatitis B vaccine, influenza vaccine, and recommendations for use of new pediatric combination vaccines. Other topics will include recommendations on use of the smallpox vaccine for prevention of monkeypox, and an update on global polio eradication. 

The live satellite broadcast and webcast will be rebroadcast from noon until 2:30 p.m. the same day. If you have questions or need further information, contact the CDC at http://www.phppo.cdc.gov/PHTN/imm-up2003/default.asp

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► Arboviral Disease Report  

No new human cases were reported this week. We have two cases of EEE, three cases of West Nile virus encephalitis and one case of WN fever reported so far this year. Seven counties are under medical alert including Bay, Brevard, Collier, Gilchrist, Lee, Okaloosa and Orange counties. 

EEE virus activity in animals: Eight horses were confirmed with EEE virus infections, bringing the YTD total for horses infected with EEE virus to 183 in 47 counties. This year so far, there are seven times the number of horses than were reported with EEE in all of last year. Twenty-one seroconversions to EEE virus from 11 counties were confirmed in sentinel chickens. Of Florida’s 67 counties, 50 have reported EEE activity, compared to 20 last year by this time. EEE activity appears to be spreading out from the central region.

WN virus activity: One WN virus infection in a horse from Marion County was reported this week, for a YTD total of two statewide. Twenty seroconversions to WN virus were confirmed in sentinel chickens, for a YTD total of 104 WN seroconversions in 24 counties. Twenty-nine dead birds were reported positive for WN virus, for a YTD total of 72. Forty-one counties have reported WN virus activity this year, with sporadic distribution around the state, compared to 27 last year by this time.

The complete report can be viewed at: http://www.doh.state.fl.us/Environment/hsee/arbo/weekly_summary2003.htm

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► Weekly Disease Table 

Click on the link below to access the latest data regarding this week's disease figures provided by the Florida Department of Health, Bureau of Epidemiology.

Current week's disease table

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