Friday, June 4, 2004

         This Week in the News
 

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

►Health Secretary Speech Sets Tone for Epidemiology Seminar
Attendees at the Ninth Statewide Epidemiology Seminar in Lake Mary heard praise from Secretary of Health John O. Agwunobi, MD, MBA, MPH and were encouraged not to settle for good when better is on the horizon.
 

►Report Measures Factors in Smallpox Attack Plan
Ideas concerning how to handle an attack via a mass smallpox outbreak were considered recently in a case study by scientists at the Los Alamos National Laboratory in New Mexico.
 

A R T I C L E S

In an uplifting keynote speech that conveyed his confidence in the capabilities of his audience, Secretary of Health John O. Agwunobi challenged Florida's epidemiologists to rise above the challenges presented by changes in world affairs, and instead strive to be the role model that other states emulate. He exhorted them to be first in the country in surveillance, first in response, and first in preparedness.

The opening day's speech provided a positive starting point for the 217 attendees gathered in Lake Mary, Florida for the 9th statewide epidemiology seminar, entitled "Emerging Issues in Epidemiology."

Dr. Agwunobi's survey of the past year's achievements stretched from involvement in the SARS crisis, to Monkeypox and the Malaria and West Nile virus outbreaks. Throughout many of these events, the incident command team structure was in place, and he emphasized the need to adhere to this proven method for successful control of a crisis situation. He used the reference to crisis management as a springboard for discussion of principled leadership and its relevence to any successful endeavor. Citing the need for exemplary leadership and vision to make an organization not just a good but a great one, he encouraged individuals to strive for personal excellence.

The secretary also reminded the assembled public health professionals, which included  epidemiologists, nurses, clinicians, and physicians, that they should serve with pride, "because it's a privilege to serve others, and it's needed, and because we're good at it."
 

Announcements. Don Ward introduced Christie Luce, the new marketing specialist and trainer for EpiCom, who will be working as a liaison with hospitals, CHDs and our EpiCom staff in the effort to familiarize hospitals with EpiCom and assist them in daily usage. Christie is also experienced in Web design.

Carmella Mancini has been hired in a leadership role in the Surveillance and Reporting section. Two of her important projects will be to move Merlin to a new level of support for CHDs and to develop a statewide plan for antibiotic resistance, including MRSA.

A new chief planner for the bureau will be hired around June 1st. The individual will be responsible for developing and managing a project planning system, and formalizing a response to activities such as legislative budget requests.

Don also reiterated that bioterrorism funds may not be used to purchase equipment. In addition, OPS employees cannot be paid from those funds. 

Epi-X Proficiency Test / EpiCom Changes. Pete Garner stated the recent test of the emergency system went very well. The bureau has also added an emergency room census to the system, which provides useful data to hospitals. 

Postal Surveillance System. Don described the new autonomous detection system which will be implemented in over 300 post offices around the country. Bio detection systems in post office buildings are standalone units situated by machinery which can identify bacillus anthracis.  If there is a positive alert, samples are sent to an approved  laboratory. In that event, five criteria will have to be met to deploy an evacuation. An upcoming issue of MMWR will carry the complete list of criteria. One of the criteria, which affects DOH staff, is that local and state health departments must be notified, and the process set in motion for crisis management.

The conference calls are scheduled for alternate Fridays at 10:00 a.m. EST. For more information, including how to be added to the agenda, contact Professional Training Coordinator Melanie Black, MSW, at melanie_black@doh.state.fl.us or phone her at 850.245.4444, ext. 2448.
 

According to Dr. Stephen Eubank, one of the scientists at the Los Alamos National Laboratory responsible for the report entitled, Modeling disease outbreaks in realistic urban social networks, the two most important factors in response to a smallpox attack are the amount of time it takes a population to withdraw from public spaces, and rapid detection of the virus.

The research team created a mathematical case study of the city of Portland, Oregon using EpiSims and Transportation Analysis and Simulation System tools, which produce highly resolved estimates and probability ratios that measure social interaction and infrastructure, to test strategies for restricting the spread of a virus.

Because disease transmission often ensues as people gather in public places and  spreads as they navigate to adjacent areas, the alternative project scenario involved positioning sensors in targeted locations around the city for early identification of infected persons. Using an overlap ratio which presumes that the total number of people visiting any location is the number of different people visiting a larger location, the team deduced that not many people visit more than one high-degree location, making early identification feasible.

They then considered active responses to casualties based on mitigation efforts, delay in carrying out the efforts, and whether persons continue daily activities while they're infected.  A passive baseline response was simulated and measured against three active responses; mass vaccination of 100 percent of the city, targeted vaccinations, and quarantine with indefinite use of resources.

Responses to simulated attacks were grouped according to baseline isolation factors, i.e., the time of withdrawal to home and whether it was early (before becoming infectious), late (about 24 hours after becoming infectious) and never (in which persons carried out normal activities unless death occurred).

The pro-active approach supported by the CDC and currently engaged in by the state of Florida, is a mass vaccination effort which would mitigate any crises in advance. The group of scientists at Los Alamos, however, have concluded that the amount of time it took to withdraw to home, combined with early identification, was the most important factor in responding to an attack.

For a complete reading of the report, log on to http://www.nature.com/nature/.
 

One of the many highlights of the seminar was Tuesday's keynote speech delivered by the  Secretary of Health. New this year was the opportunity for county health departments to display educational items, and the presence of epidemic intelligence service fellows who met and greeted conference-goers and acquainted them with the EIS program.

Winners of this year's poster session were announced at Wednesday's luncheon and presented certificates by Deputy State Health Officer Bonnie Sorensen. (Ed note: Details on the winning posters will be revealed in an article in next week's issue of the Epi Update.)                   

Data generated from the speaker and seminar evaluation forms is still being processed but a preliminary reading suggests attendees were well pleased with their accommodations, the quality of presenters, the variety of activities and the overall length and breadth of the event. This year's seminar may be hard to beat but, as Dr. Agwunobi said, "Never be satisfied being good, strive to be better!"  We'll all look forward to an even better conference next year.
 

Reprinted from MMWR May 21, 2004 54(19);412-413

► Multifocal Autochthonous Transmission of Malaria - Florida, 2003

On Friday, May 21, 2004, a report summarizing an investigation of suspected mosquito-borne malaria transmission in Okeechobee county, during the summer of 2003, was published in Morbidity and Mortality Weekly Report (MMWR) by the Center for Disease Control and Prevention (CDC). The report describes the investigation of a case of malaria initially believed to be related to a concurrent outbreak of local mosquito-borne transmission in a near-by county (Pam Beach County), but instead was confirmed as a case of imported malaria. Additionally, the report provides a discussion (in Editorial Comments) putting local mosquito-borne transmission in Florida in historical context, and emphasizing the importance of recognizing and responding to cases of malaria thought due to local transmission. The report is replicated below: (CDC. Multifocal autochthonous transmission of malaria-Florida, 2003. MMWR 2004;53:412-3).

The majority of malaria cases diagnosed in the United States are imported, usually by persons traveling from areas where malaria is endemic (1). However, small outbreaks of locally acquired mosquito-borne malaria continue to occur (2–4). During July–September 2003, an outbreak of locally acquired mosquito-borne malaria (eight cases of Plasmodium vivax malaria) occurred in Palm Beach county, Florida (5). During the same period, two symptomatic patients were evaluated for malaria in neighboring Okeechobee county, approximately 75 miles from the Palm Beach county transmission area. One patient was thought to have acquired infection with the same species (P. vivax), and concerns were raised about a possible link. To determine whether infection was acquired in Okeechobee county and to investigate a possible link to the Palm Beach county outbreak, the Florida Department of Health (FDOH) initiated an investigation. This report describes the case investigation, which determined that although initial laboratory results suggested local transmission, subsequent investigation and testing confirmed the case as imported malaria. This investigation underscores the importance of a rapid and thorough assessment for any malaria case suspected to be acquired through local mosquito-borne transmission.

In August 2003, after 4 days of subjective fever, chills, myalgia, fatigue, nausea, and headache, two men were evaluated for malaria at a local clinic in Okeechobee county. The first patient was a native of Uganda (patient 1) who had arrived in the United States 2 months before onset of symptoms; the second patient was a U.S.-born Florida resident (patient 2) with no recent foreign travel to areas where malaria is endemic or other risk factors for malaria. Both patients were treated presumptively for their symptoms with doxycycline and diclofenac, and thick and thin blood smears were obtained for testing. A private laboratory identified P. vivax on the smear from patient 1; no malaria parasites were identified on the smear from patient 2. Because of increased malaria awareness from the Palm Beach county outbreak, smears for both patients were forwarded to the Florida State Laboratory (FSL) and CDC for confirmation.

After microscopic examination of both smears, FSL and CDC observed that the smears were prepared poorly. However, malaria parasites were confirmed on the smear labeled as collected from patient 2 rather than patient 1, and P. vivax was identified as the most likely species. Because neither patient reported travel to the Palm Beach county transmission area, investigators considered the possibility of local mosquito-borne transmission in Okeechobee county. Discrepancies in the smear results reported by the private laboratory, FSL, and CDC prompted investigators to suspect the smears were switched en route to FSL. An audit was conducted to trace the positive smear to the correct patient. In addition, blood smear microscopy, serology, and polymerase chain reaction (PCR) were conducted on specimens drawn from both patients after treatment was started. The audit revealed that the positive smear originated from patient 1. No evidence of previous or current infection was confirmed in specimens for patient 2. For patient 1, serology confirmed either previous or recent infection with malaria, and PCR revealed current infection with P. ovale, not P. vivax. These conflicting results prompted a review of the original microscopic diagnosis of P. vivax. Because whole blood specimens from the original positive smear were not available, PCR analysis of material scraped from the original positive blood smear confirmed P. ovale as the diagnosis for patient 1.

In September, additional case finding was initiated to determine whether local mosquito-borne transmission occurred in Okeechobee county. Medical charts were reviewed for 232 patients with unexplained febrile illness during the 2 weeks before symptom onsets for patients 1 and 2; no other cases of malaria were found. After P. ovale was identified in patient 1, who recently arrive from malaria endemic Uganda, investigators concluded this was a case of imported malaria, and measures to control local transmission of malaria were scaled back. Patient 1 received additional treatment with primaquine to prevent relapse of P. ovale. Education materials regarding how to recognize symptoms of malaria and how to prevent mosquito-borne diseases were distributed to neighbors of patient 1. Patient 2 recovered from his symptoms without further treatment and was diagnosed with a nonspecific viral syndrome.

During September–October, Okeechobee county physicians continued to evaluate patients with febrile illness for malaria; no additional cases were found. Mosquito trapping and testing in the county confirmed the presence of competent vectors (Anopheles sp.), but no mosquitoes tested positive for malaria.

Reported by: C Selover, C Thacker, M Hill, MPH, Okeechobee County Health Dept, Okeechobee; F Lugo, MPH, Palm Beach County Health Dept, West Palm Beach; M Lo, MPH, M Pawlowicz, PhD, J Schulte, DO, C Blackmore, DVM, D Ward, L Crocket, MD, Florida Dept of Health. LM Causer, MBBS, M Parise, MD, J Barnwell, PhD, A DaSilva, PhD, Div of Parasitic Diseases, National Centers for Infectious Diseases; DF Argüello, MD, S Filler, MD, EIS officers, CDC.

Editorial Note: Approximately 60 cases of malaria are reported in Florida annually (nearly all imported), with only three outbreaks of local mosquito-borne transmission (one case of P. vivax, Bay county 1990; two and eight cases of P. vivax, Palm Beach county 1996 and 2003, respectively) reported since the 1950s (5–7). Because of its climate, proximity of human and mosquito populations, and the frequent travel of its residents and visitors from malarious areas, Florida often is perceived as vulnerable to the re-establishment of endemic malaria. However, endemic malaria was eradicated from Florida since the early 1950s, and re-establishment of endemic malaria is unlikely as long as present socioeconomic conditions, and current health care, mosquito control, and public health infrastructures remain intact (2,4).  Nevertheless, conditions exist for small outbreaks of locally acquired mosquito-borne transmission to occur sporadically.

This investigation demonstrates the need for proper smear preparation and accurate microscopic evaluation in confirming a case of malaria suspected as acquired through local mosquito-borne transmission. Errors in specimen handling and improper smear preparation made it difficult to identify which patient was infected and to decide whether control efforts were needed to prevent local mosquito-borne transmission. Investigators relied on additional laboratory methods (i.e., PCR and serology) to determine that the Okeechobee county case was not related to local mosquito-borne transmission.

Although additional testing was required to confirm the diagnosis in the Okeechobee case, microscopic examination of thick and thin blood smears remains the standard for malaria diagnosis. Once a case of malaria is confirmed microscopically, a rapid and thorough case investigation must ensue to establish whether acquisition occurred locally or abroad. Control efforts should proceed based on smear results and epidemiologic evidence and should not be delayed waiting for additional tests. Local and state health officials should recognize that a single case of malaria found to have no risk factors for malaria should be considered locally acquired through mosquito-borne transmission until proven otherwise and should be investigated immediately.

References

1. Filler S, Causer LM, Newman RD, et al. Malaria surveillance–United States, 2001. In: CDC Surveillance Summaries (July 18). MMWR 2003;52(No. SS-6).

2. Zucker JR. Changing patterns of autochthonous malaria transmission in the United States: a review of recent outbreaks. Emerg Infect Dis 1996;2:37–43.

3. Pastor A, Neely J, Goodfriend D, et al. Local transmission of Plasmodium vivax malaria—Virginia, 2002. MMWR 2002;61:921–3.

4. Humphreys M. Malaria: Poverty, Race, and Public Health in the United States. Baltimore and London: Johns Hopkins University Press, 2001.

5. Maleki JM, Kumar S, Johnson B, et al. Local transmission of Plasmodium vivax malaria—Palm Beach county, Florida, 2003. MMWR 2003;62:908–11.

6. Ginsberg M, Hunt S, Bartzen M, et al. Mosquito-transmitted malaria—California and Florida, 1990. MMWR 1991;40:106–8.

7. Mungai M, Roberts J, Barber A, et al. Malaria surveillance—United States, 1996. In: CDC Surveillance Summaries (March 30). MMWR 2001;50(No. SS-1).
         

 - The Barcelona Nut Company is conducting a voluntary recall of manof its products due to possible contamination from Salmonella Enteritidis

- A passenger from an Italian cruise liner which docked at Ft Lauderdale tested positive for  Legionellosis after arriving home in Lee County

The Bureau of Epidemiology encourages Epi Update readers to not only register on the EpiCom system at https://www.epicomfl.net but to browse EpiCom frequently and contribute public health observations related to any suspicious or unusual occurrences or circumstances, as appropriate. EpiCom is the primary method of communication between the Bureau of Epidemiology and other state medical agencies during emergency situations.
 

During the period May 23-29, the following arboviral activity (St. Louis encephalitis [SLE] virus, eastern equine encephalomyelitis [EEE] virus, Highlands J [HJ] virus, West Nile [WN] virus and dengue virus) was recorded for Florida: 

 There are no counties currently under medical alert for mosquito-borne disease.

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