Dengue and chikungunya 2016

how to diagnose and manage dengue and chikungunya

1. Dengue & Chikungunya Viral infections Arbo Viral Infections RNA viruses Prof. Ashok Rattan, MD, MAMS, INSA DFG, WHO Lab Director Academics, Industry: Research, Diagnosis, Public Health, Academics

2. Dengue Of great antiquity, clinically known in China Swahili “ ka dinga pepo ” Along with slaves ; Africa  Caribbean In Cuba (Spanish) Dinga is Dengue (fastidious) 4 closely related RNA viruses DEN 1, DEN 2, DEN 3, DEN 4 Share same geographical & ecological niche Ss RNA, flavi virus

3. Dengue Virus

4. Mosquito Transmission: Aedes aegypti and Aedes albopictus

5. Transmission: Aedes mosquito Aedes aegypti Urban mosquito Needs standing water for larvae Prefers cool, dark areas for resting Feeds through the day, most active at dawn/dusk Eggs do not survive winter in temperate climates Aedes albopictus : Asian Tiger Mosquito Urban, periurban , rural habitats Feeds through the day, most active dawn/afternoon Eggs survive winter in temperate climates Invasive- spreading in Europe and Americas www.cdc.gov

6. Course of Dengue illness

7. Lumsden WH. Trans Roy Soc Trop Med Hyg 1955;49:33-57

8. Chikungunya Virus (CHIKV): Alphavirus “ That which bends up ” in Swahili Togaviridae family Single strand RNA virus, mosquito-transmitted www.cdc.gov/ncidod/dvbid/arbor/alphavir.htm

9. 20 What is Chikungunya? Chikungunya is a virus that is transmitted from human to human mainly by infected Aedes albopictus and Aedes aegypti mosquitoes acting as the disease-carrying vector Chikungunya causes sudden onset of high fever, severe joint pain, muscle pain and headache 3 main presentations Acute: sudden onset, Severe, incapacitating polyarthralgia Maculopapular rash on trunk & extremities Subacute : Relapse of symptoms 2 to 3 months following initial infection Exacerbated pain in previously affected joints Chronic: Persistence of arthralgia & fatigue for > 3 months Prevalence in 12 to 50%

10. 21 Symptoms Symptoms include: Sudden onset of high fever Headache Back pain Myalgia Arthralgia The symptoms will appear on average 4 to 7 days (but can range from 1 to 12 days) after being bitten by an infected Aedes mosquito

11. Mosquito Transmission: Aedes aegypti and Aedes albopictus

12. Transmission: Aedes mosquito Aedes aegypti Urban mosquito Needs standing water for larvae Prefers cool, dark areas for resting Feeds through the day, most active at dawn/dusk Eggs do not survive winter in temperate climates Aedes albopictus : Asian Tiger Mosquito Urban, periurban , rural habitats Feeds through the day, most active dawn/afternoon Eggs survive winter in temperate climates Invasive- spreading in Europe and Americas www.cdc.gov

13. 24 Epidemiology Chikungunya risk zones Outbreaks of Chikungunya virus are usually found in: Africa Southeast Asia Indian subcontinent and islands in the Indian Ocean

14. CHIKV: re-emerging disease Initial descriptions in 1950s 2000 Epidemic in Kinshasa, DRC, 1 st in 39 years 2001-2003 epidemic in Indonesia, 1 st in 20 years 2004 Coastal Kenya E226V mutation more efficiently transmitted by Aedes albopictus 2005 Spread to Comoros Islands 2005-2007 Epidemic in Réunion: 35% attack rate 266,000 cases 0.1% mortality 2006 Maldives & India 2008 Singapore 2012 Rural Cambodia 44.7% prevalence 5.3% asymptomatic 2012 Bhutan 1 st cases reported Index case recent travel from India East/Central/South African genotype 2012 Papua New Guinea 1 st cases reported MMWR 2012; 61: 737-40 www.cdc.gov/eid 2013 vol 19

15. Treatment and Prevention Acute Illness Supportive care NSAIDS Case reports of short steroid courses for severe early disease Persistent arthralgias : no good data for treatment Chloroquine , hydroxychloroquine No sig difference in efficacy for acute arthralgias between chloroquine and meloxicam in 509 indiv in India Sulfasalazine, methotrexate, ribavirin, interferon-alpha Mosquito avoidance Vaccines in research, not licensed Monoclonal antibodies as prophylaxis effective in mouse models

16. Incubation Period

17. 42 What should I do if I suspect my patient has Chikungunya ? Chikungunya is a reportable disease. ECDC proposes the following reporting levels: Case categories Possible case : a patient meeting clinical criteria Probable case : a patient meeting both the clinical and epidemiological criteria Confirmed case : a patient meeting the laboratory criteria, irrespective of the clinical presentation

18. 43 Algorithm for ascertainment of suspected Chikungunya case Source : ECDC Mission Report: Chikungunya in Italy, Joint ECDC/WHO visit for a European risk assessment 17 – 21 September 2007

19. Protection Personal protection: DEET, Picaridin Household prevention: Screen, Bed nets Neighbourhood & community prevention Vector Control Same as for Dengue vector control