CHIKUNGUNYA VIRUS INFECTION Cesar Ponce S. Medical Microbiologist and Parasitologist. Epidemiologist ADC Medical Microbiology Department Director Curacao, Aug. 2014
TOPICS: Definition History Epidemiology Clinical symptoms Differential diagnosis Laboratory diagnosis Treatment Prevention CHIKV INFECTION Aug. 2014
I. Definition Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common. http://www.who.int/mediacentre/factsheets/ fs327/en/
Positive-strand RNA virus Alphavirus genus Togaviridae family CHIKV is an arthropodborne (ARBO)- virus Chikungunya virus (CHIKV) Genetic analysis on E1 envelope: 3 subtypes West 3 African cluster East-South-Central Africa (ESCA) cluster Asian cluster Robinson MC. Trans R Soc Trop Med Hyg. 1955;49:28-32
II. History: 1952 first detection, Africa Makonde Plateau outbreak Virus isolation in serum Chikungunya = the illness of the bended walker Makonde root verb kungunyala Sylvatic cicle / urban centers Africa, Asia, Europe and America 2008 listed as category C priority pathogen (NIAID) http://www.chikungunyavirusnet.com/histor y-of-chikungunya.html
III. Epidemiology: life cycle CHIKV INFECTION Aug. 2014
III. Epidemiology: Risk area
III. Epidemiology: outbreaks 1999-2000 Democratic Republic of the Congo. 2005, a major outbreak in islands of the Indian Ocean. 2006 Indian Ocean. 2006 and 2007 India. Since 2005, India, Indonesia, Thailand, Maldives and Myanmar have reported over 1.9 million cases. In 2007 first time in Europe, Italy. There were 197 cases recorded, Ae. Albopictus are plausible in Europe. December 2013, autochthonous cases in St Martin. Transmission has been confirmed in Anguilla, British Virgin Islands, Dominica, French Guiana, Guadeloupe, Martinique and St Barthelemy. Aruba only reported imported cases. As of 6 March 2014, there have been over 8000 suspected cases in the region. http://www.who.int/mediacentre/factsheets/fs327 /en/
III. Epidemiology: ChikV in America http://www.cdc.gov/chikungunya/geo/
III. Epidemiology: ChikV in the Caribbean http://www.cdc.gov/chikungunya/geo/caribb ean.html
IV. Clinical symptoms: Febrile illness Replicates skin Liver and joints High level viremia Incubation: 3-7 days Asymptomatic: 5-15% Fatality ratio: 1:1000 Neonates Underlaying conditions Older people Polyarthralgia Bilateral 96% Lower 98% Small joints 75% Maculopapular rash 48% Asthenia 89% Headache 70% Digestive trouble 63% Myalgia 59% Conjuntival hyperhemia 23% Adenopathy 9% CHIKV INFECTION Aug. 2014
Acute stage, multifocal pain 14-1-2015 12 Queyriaux et al. Lancet Infect Dis. 2008;8:2-3
Unusual clinical presentation Hepatitis Guillain-Barré Cardiologic manifestations Encephalitis Myelopathy Myopathy Mother to child transmission Deaths CHIKV INFECTION
Acute stage, joint manifestations Periarticular swelling and joint effusion 14-1-2015 RIVM, Netherlands Simon et al. Medicine, 86 (3), May 2007
Joint findings (MRI) Effusion Erosion Synovial thickening Tendinitis Tenosynovitis Chronic inflammatory erosive arthritis Chikungunya infection Aug. 2014
V. Differential diagnosis Dengue fever Leptospirosis Malaria Meningitis Post Infection arthritis Other viruses Mayaro, Rubella, Measles, Parvovirus, Enteroviruses Chikungunya infection PAHO/WHO
VI. Laboratory diagnosis General Leukopenia Thrombocytopenia Aminotransferases Hypocalcemia Lymphopenia <1000/mL Specific Antibodies detection Anti-ChikV IgM Anti-ChikV IgG Viral detection PCR Chikungunya infection Aug. 2014
Viremia and immune response Chikungunya virus infection 10 6 pfu/ml ELISA P/N CHIK viremia IgM 20 IgG Neutralizing Ab 2-14 to -2 0 1 2 3 4 5 DAYS POST ONSET 6 7 8 9 10 14-1-2015 RIVM, Netherlands
ELISA Enzyme Linked Immuno Sorbent Assay
Interpretation OD=Optical Density PC= Positive control Cut Off = Limit P/N NC= Negative control Index= OD sample OD Cut Off 1,32/0,35=3,77=P 0,15/0,35=0,42=N Index= 0,8 1,1= I
Case 1
Case 1
Case 2
Case 2
VII. Treatment No specific 14-1-2015 RIVM, Netherlands
VIII. Prevention CHIKV INFECTION Aug. 2014
Avoid mosquito bites! CHIKV INFECTION Aug. 2014
Prevention Vector control Adult Breeding Protection Nets Repelent Appropriate clothing 14-1-2015 RIVM, Netherlands
References PAHO WHO CDC, USA RIVM, Netherlands Medscape.com www.chikungunyavirusnet.com/hi story-of-chikungunya.html 14-1-2015 RIVM, Netherlands