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

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Fecha Inicio Síntomas

Cas

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mad

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Curva Epidémica de Dengue según Inicio de Síntomas Paraguay - 2007*

Total de Casos Notificados* = 28.182

592 casos

Pico Máximo de Noticación 20 de febrero - Sem Epid : 8

* Datos parciales hasta el 26 de Octubre - Sem .Epid. 43Fuente: DIVET

519

12/31 2/20 5/27

Monath T. N Engl J Med 2007;357:2222-2225

Dengue Microbiology

Vector Biology

Aedes Species

Aedes Species

Cycle in Nature Urban / semi-urban Epidemic cycle

Rural – Urban Cycle

Aedes aegypti

Aedes aegypti

Symptoms

Fever

Headache

Retro Orbital Pain

Myalgias/Arthralgias

Nausea and Vomiting

Weakness

Rash

Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932

Dengue Rash with Sparing of Islands of Skin

Diagnosis

Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932

Positive Result on a Tourniquet Test

Laboratory Tests

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Figure 2 Representation of the temporal appearance of virus ,IgM,and IgG antibodies in persons infected with dengue virus.

Viremia

IgM

IgG(1)

IgG(2)

Wilder-Smith A and Schwartz E. N Engl J Med 2005;353:924-932

Suspected Cases of Dengue Clinical and Epidemiologic Criteria

Group A Ambulatory care from homePatient or caretaker instructed regarding warning signs and directed to urgently consult medical attention with one or more warning signs.Follow up within 24 hours

Alarming Signs ***Shock

Bleeding*DehydrationLittle or no oral intakeClinical EdemaComorbidities**

Absent

Group CSuspected cases of moderate DHF/DSS (reversible shock)Hospitalize in specialized units

Grupo DSuspected cases of Severe DHF/DSS (Refractory shock or recurrent treatment with cristaloids or prolonged shock)Hospitalizein the ICU

Group BSuspected cases of complicated Dengue orMild DHF(Hematocrit and Platlets)Hospitalize for observationOral re-hydration or IV if the can not tolerate fluids PO

* 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.

One of more Alarming signs

Outpatient

Inpatient

Figure 1

Wills B et al. N Engl J Med 2005;353:877-889

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

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