Dengue Fever
History, Biology, Pathology, Clinical Management, and
Prevention.
San Estanislao, Paraguay
February, 2008
Blair Thedinger
Dengue Fever Hits Paraguay
By REUTERS
Published: March 4, 2007
ASUNCIÓN, Paraguay, March 2 — A Supreme Court
justice, soccer players and a senator have come down
with dengue in Paraguay, as the worst outbreak in the
country’s history hit the well off as well as its usual
victims among the poor.
On Friday, a nurse who worked with the public health
service died after being hospitalized for dengue…
Dengue History
Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932
Geographic distribution of Aedes aegypti in the
Americas,
Dengue Worldwide Today
Epidemia No caracterizada año 1988/1989 (40,000)
IgM +
● Año 2000
DEN-1
24,282
(estimaciones 300,000)
● Año 2001
DEN-2
38
● Año 2002
DEN-1,2,3
130
● Año 2003
DEN-1,3
137
● Año 2004
DEN-3
12
● Año 2005
DEN-2
36
● Año 2006
DEN-3
1.889
● Año 2007
DEN 3
6.313
Curva Epidémica de Dengue según Inicio de Síntomas
Paraguay - 2007*
700
Total de Casos Notificados* = 28.182
Pico Máximo de Noticación
20 de febrero - Sem Epid : 8
519
600
592 casos
Casos Confirmados
500
400
300
200
100
0
5-8
-7
29
-7
22
-7
15
8-7
1-7
-6
24
-6
17
-6
10
5/27
3-6
-5
27
-5
20
-5
13
6-5
-4
29
-4
22
-4
15
8-4
1-4
-3
25
-3
18
-3
11
2/20
4-3
-2
25
-2
18
-2
11
4-2
-1
28
-1
21
-1
14
7-1
-12
31
12/31
Fecha Inicio Síntomas
* Datos parciales hasta el 26 de Octubre - Sem .Epid. 43
Fuente: DIVET
Monath T. N Engl J Med 2007;357:2222-2225
Dengue Microbiology
Cycle in Nature
Rural – Urban
Cycle
Urban / semi-urban
Epidemic cycle
AedesBiology
Vector
Species
Aedes
aegypti
Aedes
Species
Aedes
aegypti
Symptoms
Fever
Headache
Retro Orbital Pain
Myalgias/Arthralgias
Nausea and Vomiting
Weakness
Rash
Dengue Rash with Sparing of Islands of Skin
Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932
Diagnosis
Positive Result on a Tourniquet Test
Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932
Laboratory Tests
.gif
Viremia
IgM
IgG(1)
IgG(2)
Figure 2 Representation of the temporal appearance of virus ,IgM,and IgG
antibodies in persons infected with dengue virus.
Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932
Figure 1
Suspected Cases of Dengue
Clinical and Epidemiologic Criteria
Outpatient
Bleeding*
Dehydration
Little or no oral intake
Clinical Edema
Comorbidities**
Absent
Alarming Signs ***
Shock
Group A
Ambulatory care from home
Patient or caretaker instructed regarding
warning signs and directed to urgently consult
medical attention with one or more warning
signs.
Follow up within 24 hours
Inpatient
Group B
Suspected cases of
complicated Dengue or
Mild DHF
(Hematocrit and Platlets)
Hospitalize for observation
Oral re-hydration or IV if the
can not tolerate fluids PO
One of more
Alarming signs
* Spontaneous or provoked bleeding
** Comorbidities incluye: Cardiovascular disease, Diabetes,
Immunosuppresed, Kidney disease, Malnutrition, Anemia, Asthmatics,etc.
*** Clinical signs: Moderate to intense abdominal pain, persistent vomiting,
sharp drop in temperature, changesin the level of consciousness, Postural
Hypotention, pulse pressure <20 mmHg
Labratory signs: Progressive rise in hematrocrit, progressive fall
in platelets.
Group C
Suspected cases of moderate DHF/DSS
(reversible shock)
Hospitalize in specialized units
Grupo D
Suspected cases of Severe
DHF/DSS (Refractory
shock or recurrent
treatment with cristaloids
or prolonged shock)
Hospitalizein the ICU
Kaplan-Meier Curves for Time from Study Entry to Initial (Panel A) and Sustained (Panel B)
Cardiovascular Stability among Children in Group 1, According to the Resuscitation Fluid Received
Wills B et al. N Engl J Med 2005;353:877-889
Prevention and Vector Control
• Vaccine
• Vector Control
• Challenges to
Prevention
Monath T. N Engl J Med 2007;357:2222-2225
Challenges
Challenges
Challenges
Looking Ahead