Mosquito-borne Disease on Statia:Dengue, Chikungunya and Beyond

Joe Wagman, Ph.D.Belize Vector and Ecology Center

Science Café at theCaribbean Netherlands Science Institute

April 2015

Tonight’s Outline

• Dengue and Chikungunya Viruses: The basics– Disease Symptoms and Natural History– Burden of Disease/Epidemiology– Disease Transmission

• Other viruses vectored by Aedes• Current work on Statia• Vector Surveillance and Control• Future Research Possibilities• Summary• Questions and Discussion

Mosquito-Borne Disease: A global threat

DENV and CHIKV: The Basics

Both are mosquito-borne viruses, spread by the same species of mosquitoes (primarily Aedes aegypti and Aedes albopictus).

US CDC Public image Library US CDC Public image Library

Aedes aegypti Aedes albopictus

DENV and CHIKV: The Basics

• Flavivirus (Yellow Fever)

• Hosts include only humans and other non-human primates

• 4 serotypes

Zhang et al., 2013. Nat. Struct. Mol. Biol.20(1):105-10

• Alphavirus (VEE)

• Can also infect birds, cattle, and rodents

• 1 serotype

Sun, et al., 2013. Elife 2:00435

DENV CHIKV

Symptoms

Dengue Fever•May be asymptomatic or uncomplicated fever

•Sudden High Fever (Cyclical)

•Headache (behind the eyes)

•Muscle and joint pains (“breakbone fever”)

•Rash

•Nausea and Vomiting

•Severe Dengue (rare, <5%) = all of the above with:

•Hemorrhage and Bleeding

•Fluid Imbalances

•Shock

Chikungunya Fever•May be asymptomatic or uncomplicated fever

•Sudden High Fever (Cyclical)

•Muscle and joint pains (“that which bends you up”)

•Headache

•Rash

•Nausea and Vomiting

•No hemorrhagic complications like dengue

•Symptoms can last months to years in some patients

Disease Burden

Dengue Fever

•4 Serotypes

•Every Year:

•400 Million infections

• 500,000 hospitalizations

•25,000 deaths

•Large outbreaks can cost as much as $100million USD in lost productivity

http://www.who.int/en

http://www.cdc.govStahl HC, Butenschoen VM, Tran HT, Gozzer E, Skewes R, et al. 2013. BMC Public Health 13:1048

Disease Burden

Disease Burden

Chikungunya fever

•New to the Americas

•St. Martin, DEC 2013

•1.25 million cases reported by PAHO in March, 2015

http://www.who.int/en

http://www.cdc.gov

Chikungunya on Statia, 2015:At least 300 cases

300/3,000 = 10% of population (probably a large underestimate)

Disease Burden

Disease Transmission

Disease Transmission

• No Vaccines

• No specific drugs or therapy

– Acetaminophen (Tylenol) for pain and fever

– Hydration

– Rest

– Avoid Mosquitoes!

• VECTOR CONTROL

– “Know the vector, know the threat”

Disease Transmission

The mosquito Aedes aegypti is the most important DENV vector

Vector Distribution on Statia: Everyone at Risk

Couch, WJ. 2013. Surveillance and Spatial Characterization of Ae. aegypti in St. Eustatius

Vector Surveillance and Control

• Mosquito Life Cycle

Vector Surveillance and Control

• Which mosquitoes bite human?

– (A) Males

– (B) Females

– (C) Both

• What attracts mosquitoes to people?

– (A) Colors

– (B) Smells

– (C) Body Heat

– (D) All of the above

Vector Surveillance and Control

Vector Surveillance and Control

Vector Surveillance and Control

Vector Surveillance and Control

Typical Dengue control activities include:• Source Reduction/Larvaciding (Temephos/Bti)• Truck mounted ULV spraying• Handheld thermal fogging• Public Outreach and Personal Protection

Vector Surveillance and ControlSource Reduction

Vector Surveillance and ControlTruck Spraying

House Spraying

Vector Surveillance and ControlPublic Outreach

On the Horizon: Other Viruses Vectored by Aedes mosquitoes

Current Work in Statia

• Oviposition Trap Surveillance

• Determine presence and distribution of Aedes albopictus

• Describe Insecticide Susceptibility Patterns on the Island

Summary/Future Work• Dengue, Chikungunya and other Aedes aegypti

spread viruses are a constant threat on Statiaand throughout the Caribbean

• Vector Control is currently the only preventative measure available: How can we improve?

• BVEC, The University of Notre Dame, CNSI, ECPHF, and the Statia Department of Public Health– Local Capacity Building and Collaboration

– Basic Research (ND Students)

Thank You!

John GriecoNicole AcheeSusana Castillo

Teresa Leslie

Carol John

Gerwyn Schobe

Rodney Vlitjeg

Javier GomezJohan Stapel

Pepita Cannegieter