Chikungunya Virus Infections

Jeffrey M. Bender, MD Pediatric Infectious Diseases No disclosures

2 Objectives

1. Understand the basic epidemiology and virology of Chikungunya. 2. Be able to identify Chikungunya virus infections clinically and know which labs to send to confirm the diagnosis. 3. Discuss current treatment and prevention measures.

3 Objectives

4 Chikungunya Virus

(pronunciation: \chik-en-gun-ye)

• RNA virus • + sense • Single strand • Enveloped • Member: • Family Togaviridae • Genus Alphavirus

5 Transmission

Bite of infected mosquito • Females • Aedes spp.

Very Rarely • Transfusion • In utero

6 7 • Mate Aedes Life Cycle • Blood meal Egg to mature pupae= • Rest and digest 2-3 5-14 days days • Lay 50-100 eggs • Repeat

Adult Lifespan • Males 5-7 days • Females 1 month

CDC.gov 8 Anopheles Aedes Aedes aegypti gambiae albopictus

• Dawn and dusk • Day time feeders feeders • Responsible for Yellow Fever, Dengue, • Responsible for Chikungunya, Eastern Equine Malaria • More resistant to desiccation • Poor fliers • More aggressive

9 Aedes aegypti 2014

• Red = regions of widespread Dengue transmission • Blue= regions with A. aegypti and potential transmission

CDC.gov 10 Distribution of Aedes aegypti in US Approximate distribution of Aedes aegypti in the Untied States*

Historic data (Morlan and Tinker 1965) Recent information (Eisen and Moore 2013)

*This map was developed using currently available information. Aedes aegypti mosquito populations (a known vector of chikungunya) may be detected in areas not shaded on this map, and may not be CDC.govconsisten tly found in all shaded areas. The shaded areas are NOT loactions of chikungunya transmission. 11 Aedes albopictus

www.Cell.com 12 Aedes albopictus

13 autochthonous

CDC.gov 14 allochthonous

CDC.gov 15 Discovery

• 1952 - Outbreak of Chikungunya detected in Makonde Plateau, Tanzania • 1955 - Marion Robinson and W.H.R. Lumsden identified and described Chikungunya

16 Spread to India

• 1963/64 - Chikungunya detected in Calcutta, Maharashtra, and Vellore, India – 200 deaths with outbreak in Calcutta • 1969 - Chikungunya detected in Sri Lanka

17 Further Spread

• 1975 - Chikungunya detected in Vietnam and Myanmar. • 1982 - Chikungunya detected in Indonesia. • 1990’s – Chikungunya spread through equatorial Africa and into South Africa.

18 • 2005/2006 - Chikungunya was reported in Madagascar – 100 people died due to the disease on Reunion Island • 2008 - Infection was reported in Italy, Signapore, and Australia.

19 20 Western Hemisphere

• December 2013- World Health Organization reported the first local transmission of chikungunya virus in the Western Hemisphere, with autochthonous (locally acquired) cases identified in Saint Martin

MMWR, June 6, 2014 / 63(22). 21 • 2014 – Significant spread throughout Caribbean, Central America, and South America • 1,135,892 reported cases as of 1/23/2015 (176 deaths) • 11 cases of autochthonous spread in Florida

22 Worldwide distribution of Chikungunya cases as of January 13, 2015.

CDC.gov 23 2012 2014

CDC.gov 24 Arbonet

Average cases pre-2014 = 28 (range 5-65)

Number of cases in 2014 = • 2333 imported (77 in CA) • 11 locallly- acquired (all in FL)

CDC.gov 25 26 Objectives

27 Clinical manifestations • Most people infected with Chikungunya virus will develop some symptoms • Symptoms usually begin 3–7 days after being bitten by an infected mosquito • The most common symptoms are fever and polyarthralgia • Minor Symptoms include: – Headache – Muscle pain – Joint swelling – Rash – Nausea – Conjunctivitis

Clinical manifestations

• High risk – Newborns infected around the time of birth – Pregnant mothers – Older adults (≥65 years) – People with medical conditions such as high blood pressure, diabetes, or heart disease • Most patients feel better within a week – Joint pain may persist for months • Low mortality

29 PAHO.org 30 PAHO.org 31 PAHO.org 32 PAHO.org 33 PAHO.org 34 PAHO.org 35 Key Differences

Chikungunya Dengue • Aedes spp. • Aedes spp. • 3-7 day incubation • 3-14 day incubation • Fever, rash and • Fever, rash and polyarthralgia polyarthralgia • No critical phase • Critical phase – Capillary leak – Thrombocytopenia • No hemorrhagic fever • Hemorrhagic fever • Mandatory reporting • Mandatory reporting

36 CDC.gov 37 CDC.gov 38 PAHO.org 39 Diagnostic Testing • Serology – IGM positive within 6-7 days – Acute and convalescent serum for IgG • Molecular assays - PCR

• Samples collected in serum separator tubes or red tops and spun – Not green or purple tops

• Available through some commercial laboratories, CDPH, and CDC • Report to LACDPH (888) 397-3778 (mandatory as of 1/1/2015)

40 Objectives

41 Treatment

1. Rest 2. Fluids 3. NSAIDs

Lifelong immunity

42 Infection Prevention

43 CDC.gov 44 Prevention

• Mosquito avoidance – DEET – Netting – Clothing • Mosquito control – Water sources – Pesticides

• In development – Vaccines – Genetic vector manipulation

45 CDC.gov 46 Question 1

• Chikungunya virus is a member of which family of viruses?

A. Filoviridae B. Flaviviridae C. Feverviridae D. Togaviridae

47 Question 2

• A patient presents to your clinic with a high fever, rash, and significant joint pain. If this is Chikungunya virus infection, when was your patient most likely bitten by a mosquito?

A. 1-2 days ago B. 3-7 days ago C. 8-14 days ago D. Up to 21 days ago

48 Question 3

• Your patient who just returned home from a vacation in Saint Martin, is admitted with severe joint pain and high fevers. You suspect Chikungunya virus infection. Which of the following antivirals is a recommended therapy for Chikungunya virus?

A. Acyclovir B. Cidofivir C. Foscarnet D. None of the above

49 Objectives

50 THANK YOU