Transcript Dengue in Florida

Re-emergence of locally
acquired Dengue Fever in
Palm Beach County,
Florida
Robert Parkes, MD; Sandra Warren, MPH,
JoEllen Alvarez, RN, MPH,
Barbara Johnson, RN, BSN, Epidemiology Unit, Palm Beach
County Health Department; John Pellosie, JR.,D.O., MPH.,
FAOCOPM, Chair, Department of Preventive Medicine, Nova
Southeastern University
Alina Alonso, MD, Director, Palm Beach County Health
Department
Dengue Virus
• Single-stranded RNA flavivirus
• Arbovirus (Arthropod-Born) Vector =
mosquitoes
• Same virus family that causes West Nile
fever, St. Louis encephalitis, yellow fever
• Causes dengue and dengue hemorrhagic
fever
Dengue Virus
• Four virus serotypes (DENV-1, 2, 3, 4)
• Provides specific life-time immunity for
that serotype only
• Presence of a serotype may cause
infection with a different serotype to be
worse
Common Dengue Vectors
Aedes aegypti
and
Aedes albopictus
Incubation / Viremic Periods
Source: CDC
Dengue Fever
• Often mild, non-specific
• Sudden onset of high fever
• Severe headache
• Pain behind the eyes
• Body aches and joint pains
• Nausea or vomiting
• Rash
Dengue Hemorrhagic Fever
• Severe abdominal pain
• Bleeding from the nose, mouth, and gums
• Frequent vomiting with or without blood
• Black stools
• Excessive thirst
• Pale, cold skin
• Restlessness or sleepiness
Dengue Epidemiology
• Re-emerging infectious diseases in the world
• 50 to 100 million cases annually
• 500,000 hospitalizations
• 22,000 deaths (mostly children)
• Occurs in explosive epidemics
Dengue World Distribution in 2008
Dengue in the Americas
1980 – 2009
Dengue in USA
• During 1946--1980, no cases of dengue acquired
in the continental United States were reported.
• Since 1980, a few locally acquired U.S. cases
have been confirmed along the Texas-Mexico
border
• Temporally associated with large outbreaks in
neighboring Mexican cities
Dengue in Florida
• Dengue previously endemic
• Increase in imported cases
• Warm climate, regular rainfall
• Abundant vectors
Imported Dengue in Florida
IMPORTED DENGUE FEVER
160
140
120
100
80
60
40
20
0
1997 - 2011
1986 – 2008:
Puerto Rico (41); Dominican Republic (21); Haiti (13)
2011:
Bahamas (9); Puerto Rico (7); Haiti (3), Colombia (3), Trinidad
(3)
Vector Presence in Florida
Dengue Fever in Key West, 2009
• September 1 - Monroe County Health
Department notified of a New York resident
diagnosed with dengue after travel to Key West
• Issued a press release to the public and notified
area physicians of potential for local
transmission of dengue
• Florida Keys Mosquito Control District
implemented enhanced trapping and spraying of
Aedes aegypti
Number of locally acquired dengue cases (N = 28),
by week of illness onset and method of
identification --- Key West, Florida, 2009--2010
Locally acquired Dengue in Florida
Cumulative 2011 Data as of 3 am, Dec 14, 2011
Palm Beach County Dengue Cases 2005-2011
Acquired in
FL
Acquired in
US, not FL
Acquired
outside of US
2005
0
0
3
2006
0
0
3
2007
0
0
5
2008
0
0
4
2009
0
0
1
2010
0
0
7
2011
2
0
9
Purpose
• To present two cases of locally acquired
dengue fever in Palm Beach County,
Florida in 2011
• To highlight the need for continued
surveillance
Methods
• Case interviews and medical records
review
• Confirmatory testing using enzyme-linked
immunosorbent (ELISA) and real time
polymerase chain reaction (PCR)/reverse
transcriptase PCR (RT-PCR)
Methods
• Transmission from recent imported cases
and travel companions was assessed.
• Environmental evaluation
• Classified using the Dengue Fever case
definitions for reportable diseases in
Florida (1)
Case Classification
Confirmed: a clinically compatible case that is
laboratory confirmed
Test
Days post onset
Explanation
Interpretation
Real time PCR
≤ 5days
Patient viremic while febrile
Confirmatory
≤ 5days for acute
>5 days for convalescent
Negative IgM in acute followed
by a positive IgM in
convalescent specimen
Confirmatory
≤ 5days for acute
>5 days for convalescent
Must be a 4 fold increase in
titer between acute and
convalescent
Confirmatory
IgM antibodies demonstrated in
cerebrospinal fluid
Confirmatory
IgM (paired
specimens,
acute and
convalescent)
IgG (paired
specimens,acute
and
convalescent)
IgM antibody in
CSF
Case Classification
Probable: a clinically compatible case with
supportive serologic findings
• A positive IgM antibody test on a single acute
(late)- or convalescent-phase serum specimen to
one or more dengue virus
Case Classification
Suspect: a clinically compatible case with both
epidemiologic linkage criteria
• Travel to a dengue endemic country, OR
• Presence at a location with an ongoing outbreak within
previous two weeks of dengue-like illness, OR
• Association in time and place with a confirmed or
probable dengue case
Results
• CASE 1:
• On 9/30/2011, PBCHD received a positive lab for
Dengue IgG
• 49 yr female, fever, sweating, fatigue
• DENV-1 positive by PCR/RT-PCR in acute serum
• IgG antibodies positive in acute and
convalescent serum
Results
• CASE 2:
• On 10/3/2011, PBCHD received a positive lab for Dengue
IgG
• 23 yr male, fever, chills, headache, fatigue and
meningeal signs
• IgM and IgG antibodies positive in acute and
convalescent serum
• Serological findings consistent with previous infection of
dengue fever (3)
Results
• Case 1 traveled to Haiti one month before onset
of illness, outside incubation period (2)
• None of case 1 travel companions were sick
• Case 2 had no travel history outside Florida or
the U.S.
• Secondary transmission ruled out from recently
imported cases
Results
• Environmental investigation – Aedes
albopictus for both cases.
Conclusion
• Case 1- confirmed dengue fever
• Case 2- probable dengue fever
• Both acquired locally in Palm Beach
County, Florida
• Both cases recovered
Control efforts implemented
• County-wide mosquito advisory/alert were
enacted
• Information and updates were provided
• Enhanced surveillance continued
• No new cases have occurred
Conclusion
• It is essential to continue surveillance for
Dengue Fever in Florida.
References
• 1. Florida Department of Health Bureau of Epidemiology. Surveillance case
definitions for Select reportable diseases in Florida. Retrieved February 15,
2012, from
http://www.doh.state.fl.us/disease_ctrl/epi/surv/CaseDefJan2010.pdf
• 2. Heymann,D.L., (Ed.). (2008). Control of communicable diseases manual.
Washington: American Public Health Association.
• 3. Centers for Disease Control and Prevention. Dengue laboratory guidance
and diagnostic testing. Retrieved February 15, 2012, from
http://www.cdc.gov/dengue/clinicalLab/laboratory.html