Flight Surgeon RSV Day

I n t e g r i t y - S e r v i c e - E x c e l l e n c e

ANGRCJoint Base Andrews

UNCLASSIFIED

UNCLASSIFIED

Tropical Medicine : Dengue Fever

Bryan S. Delage MD COL MC FS SASJFHQ North Dakota National Guard

26 July 2014

2

Dengue Fever

• I have no pharmaceutical bias or relationship to report

3

Patient

• Jim was a 61 y.o. male, who had returned from the Dominican Republic on vacation and presented to his primary care physician after a week of fever, and chills and not feeling well, with some fatigue myalgias and headache.

• His primary care physician sent blood work to rule out malaria, and then after the patient had left came to my office to ask the question – What do you think is going on with this guy ?

• Blood work returned normal, and the patient had defervesced, and had no further sequelae

4

What’s your Diagnosis

• So what would your answer be ?

• Obviously a definitive diagnosis cannot be had with limited laboratory testing,

• But ……. A case can be made for Dengue Fever!

5

6

Tropical Medicine- Dengue Fever

• Dengue Fever –• 1. Overview• 2. Signs and Symptoms• 3. Clinical Course• 4. Diagnosis• 5. Treatment and Management

Dengue Fever

• Overview:• Dengue virus is one of

the leading causes of illness and death in tropical and subtropical areas

• 400 million people are infected with the 4 strains of Dengue virus yearly

• It is caused by 4 distinct serotypes of the dengue virus (DENV, called DENV1, ..2, ..3, ..4)

• Single stranded RNA virus• A Flavivirus in the family

Flaviviridae • Other viruses in this group

that are important (Yellow Fever Virus, West Nile Virus, Japanese and St. Louis Encephalitis viruses)

7

Dengue Fever

• Overview (cont.) :• It is an arbovirus, which

means it is arthropod-borne, and is transmitted primarily through an infected Aedes species of mosquito; but can be transmitted by blood transfusion, organ transplant, or by needle stick (all of these from an infected individual)

8

Dengue Fever

Signs and Symptoms:• Infection with Dengue

virus can manifest in a spectrum of Dengue that ranges from an acute mild febrile illness to classic dengue fever, to the severe forms of the disease DHF ( Dengue Hemorrhagic Fever) and DSS ( Dengue Shock Syndrome)

9

• About 75% of Dengue infections are asymptomatic, and 25% symptomatic , most symptomatic infections present as a mild to moderate acute febrile illness; up to 5% can develop severe life threatening disease.

Dengue Fever- Clinical Course

• The illness begins abruptly after an incubation of 4 – 7 days (range 3-14 days).

• It typically goes through 3 phases- febrile, critical and convalescent

• The Fever lasts 2 to 7 days,

• Signs and Symptoms include: severe headache, retro-orbital pain, muscle and joint, as well as bone pain. A macular or maculo-papular rash, and can include petechiae, ecchymosis, purpura, epistaxis, bleeding gums, hematuria

10

Dengue Fever – Clinical Course

• The severe forms of DHF and DSS tend to occur at the time of defervescence and on or about day 7, a high index of suspicion and early supportive care with fluid resuscitation and colloid replacement for the critical 24 to 48 hours can improve outcome.

11

Dengue Fever- Clinical Course

• Markers for more serious disease include severe abdominal pain, persistent nausea, and vomiting, bleeding mucosa, difficulty breathing (pulmonary edema), hypovolemic shock, abrupt thrombocytopenia, and increased hematocrit due to hemo-concentration.

• Patients will typically improve during this 24-48 hour critical phase, but patients with severe plasma leakage may have a marked drop in BP, and irreversible shock and death may occur. Also hemorrhagic complications including hematemesis, melena and hematochezia, or menorrhagia

12

Dengue Fever – Clinical Course

• If patients can be supported through this critical phase with fluids, colloid and transfusions, as the plasma leakage starts to subside, and fluid is re-absorbed their hemodynamics will stabilize, and a natural diuresis will typically start to reverse the fluid retention, and edema as well as ascites.

• Hematocrit may drop due to dilution effects as fluid is reabsorbed, and white count starts to rise, and then a slow recovery of platelets. During the convalescent phase the rash may desquamate and become pruritic.

13

Dengue Fever – Lab Findings

• There can be leukopenia, as well as thrombocytopenia, hyponatremia, AST, and ALT elevation, and sed rates typically remain stable.

• Lab confirmation can be made from a single acute phase serum specimen that is drawn early <= to 5 days from onset of fever; with Reverse Transcriptase – PCR for DENV genomic sequences, or immunoassay for DENV nonstructural protein 1 (NS 1)

• Later in the course ( 4 days or more after onset of fever) the PCR or NS1; and IgM anti-DENV may be confirmatory

14

Dengue Fever- Diagnosis

• The diagnosis of Dengue should be considered in a patient presenting with fever who was in an endemic area within 2 weeks of the onset of illness, that persists, and should be reported to the local health department; as it is nationally reportable

• As listed on the last slide confirmation by RT- PCR or Immunoassay for NS1 are confirmatory, and IgM- anti-DENV suggests a likely recent DENV infection

15

Dengue – Endemic Areas

• Dengue is a tropical and sub-tropical disease, and its distribution is throughout central and South America, the Caribbean, Southeast Asia and Africa, who’s range has increased over time.

16

Dengue Fever – Endemic Areas

• Africa

17

Dengue Fever- Endemic Areas

• Pacific and Asia

18

Treatment and Management

• There is no anti-viral medication that is effective for Dengue

• Treatment is aimed at symptoms, and

• Treatment of severe cases such as DHF or DSS, includes fluid replacement, treatment or coagulation disorders, and colloid, crystalloid and isotonic fluids until the symptoms start to abate.

19

Treatment and Management

• Close monitoring for development of more serious dengue,

• Avoidance of ASA, and other NSAID’s with the increased bleeding risk

• Confirmed or suspected cases need to be reported to the State Health Department and CDC.

20

Another Possibility ?

21

Chikungunya Virus

• Arbovirus• Similar symptoms to

Dengue Fever

• http://www.cdc.gov/media/DPK/2014/dpk-chikungunya.html?s_cid=cdc_homepage_whatsnew_001

22

Chickungunya virus

• Transmitted by an Aedes mosquito, predominantly Aedes aegypti, and Aedes albopictus

• Humans are the primary host

• Blood borne transmission is possible, as well as in utero and is found in breast milk

23

Chikungunya

• Now there are cases found in the US

• Incubation is 3-7 days, • Usually marked by the

acute onset of fever and polyarthralgia

• Usually symptoms are bilateral, symmetric, and severe and debilitating

• Other symptoms include headache, myalgia, arthritis, nausea and vomiting, as well as a rash that is maculo-papular

• http://www.cdc.gov/chikungunya/geo/united-states.html

24

Chikungunya

• Preliminary diagnosis is based on clinical feature’s, places and dates of travel; and activities

• Lab diagnosis by testing of serum or plasma for virus, viral nucleic acid or virus specific IgM

• Chikungunya testing is done at the CDC, a few state health departments, and one commercial laboratory

• Viral culture in the first 3 days of illness may be utilized

• Chikungunya virus antibodies normally develop toward the end of the first week of illness

25

Chikungunya

• Instructions for sending samples can be found on the CDC website

• There are no serious forms like in Dengue, no DHF or DSS variants

• There is some increased morbidity and mortality at the extremes of age

• Symptoms can persist, especially the arthralgia for prolonged periods of time

• http://www.cdc.gov/chikungunya/geo/americas.html

26

Summary

• Dengue Fever is an acute febrile illness seen throughout the tropics and subtropics

• Diagnosis can be done by RT-PCR less than 5 days and immunoassay for NS 1, as well as IgM for DENV later

• There are more serious manifestations that can result in increased morbidity and mortality (DHF and DSS) that typically occur about the 7th day at about the time of defervescence, and need aggressive fluid management and possible transfusion of blood products, and management of bleeding

• Service members traveling to these areas especially the carribbean and other tropics need to be informed about the need to use protective measures to avoid infection,

• Also information on chikungunya and need to use measures to avoid infection with clothing and repellant in this case as well

27

Summary

• In both cases, suspected cases need to be reported to the CDC through the State Health Department.

28

Bibliography

• Dengue haemorrhagic fever; Diagnosis, treatment, prevention and control; 2nd edition, World Health Organization , Geneva, 1997

• CDC.gov

• http://www.cdc.gov/media/DPK/2014/dpk-chikungunya.html?s_cid=cdc_homepage_whatsnew_001

29