Chikungunya FeverRAFAEL BELLO CORASSA
LUIZ ALBERTO LOPEZ QUINTAS FILHO
RODRIGO FREIRE BORGES
IntroductionViral disease;
Mosquito-borne:◦ Aedes aegypti and Aedes albopictus;
Incubation period of 4-7 days;
Rarely fatal;
Arthralgia may persist for months, or even years;
Can become cause ou Chronic pain and disability.
Symptoms:◦ High fever – 40⁰ C;
◦ Joint pain and swelling;
◦ Rash;
◦ Headache;
◦ Muscle pain;
◦ Nausea;
◦ Fatigue.
WHO, 2014; PAHO, 2014
TransmissionInfected mosquito bites;
◦ Become infected when feed on na infectedperson, or other hosts (mokeys, rodents, birds);
Thiberville et al., 2013; CDC, 2014; PAHO, 2014
Figure 1: Mosquitoes of the Aedes gender.Source: Centers for Disease Control and Prevention, 2014Available at: http://www.cdc.gov/chikungunya/pdfs/CHIKV_FACTSHEET_CDC_Generalpublic(09-17-2014).pdf
Figure 2: Life-cycle of Chikungunya virus in Africa.Source: Thiboutot et al., 2010.
Aedes mosquitos have shown a large geographical expansion
◦ Risk for the establishment of the disease
A. aegypti was considered the primary vector until 2006;
A. albopictus: Ranked as the most invasivespecies of mosquito in the world;
◦ Capable of adapting to the peridomesticenvironment.
It is found in places where the A. aegypti israre and where it is prevalent;
According to Medlock et al. (2012), A. albopictus presents a major threat to publichealth in Europe.
Medlock et al., 2012; Tomasello and Schlagenhauf, 2013; Thiberville et al., 2013
EpidemiologyOriginal endemic areas: Africa, Asia and Indiansubcontinent;
Outbreaks showed to be unpredictable:◦ Intervals of 7-20 years between individual
epidemics
◦ Intervals of 4-5 decades between major epidemics
2004: Virus caused massive outbreaks in Asiaand Africa:
◦ More than 2 million infections;
◦ Attack rates reaching 68% in some areas.
Thiberville et al., 2013; CDC, 2014; PAHO, 2014
Epidemiology2004: Epidemics started in Kenya:
◦ Spead to islands of the Indian Ocean and India;
Early 2005: Comoros islands:◦ Approximately 2/3 of the population were
infected;
Mid 2005: Island of La Réunion◦ Attack rate: 34%; Mortality rate: 0.1%
◦ Virus spread to the Seychelles, Mauritius, Maldives and other Indian Ocean islands;
2007: First reports of the disease in Europe:◦ Index Case: Man returning from India;
◦ Outbreak in North-eastern Italy;
◦ Attack rate: 5.4%; Mortality rate: 0.5%;
◦ Molecular analysis:◦ E1-226V mutation;
◦ Presence of Aedes albopictus.
Tomasello and Schlagenhauf, 2013; PAHO, 2014
2010: Cases of Chikungunya in France:◦ Index Case: Girl coming from India;
◦ Three weeks later: Two other girls got sick.
2013: First cases of authoctonous transmissionin the Americas:
◦ Caribbean.
PAHO Epidemiological Alert (August, 2014)◦ 33 countries and territories in the Americas
◦ 659,367 suspected cases and 37 deaths◦ Mortality rate: 0.05 per thousand infected people
Update from CDC (November, 2014)◦ 39 countries
◦ 874,103 suspected cases and 16,669 laboratory confirmed cases
Tomasello and Schlagenhauf, 2013
Figure 3: Countries and territories with reported cases of Chikungunya, 2014
CDC, 2014
Arunachalam et al., 2009
Figure 4: Diagram for the determinants of Chikungunya disease.
Vector EcologyClimate:
◦ Abundant rain;
◦ High temperatures;
Availability of breeding sites:◦ Deposits of stagnant water;
Feeding opportunities;
Vector capacity.
Virus strain;◦ 3 diferent strains;
E1-226V mutation;◦ Facilitate the transmission through A. albopictus.
Source: http://www.thehindu.com/news/cities/chennai/181-cases-of-dengue-reported-this-year/article3559831.ece
Arunachalam et al., 2009; Tomasello and Schlagenhauf, 2013
Virus biology
Social and ecological contextPopulation/Societal
◦ Population density: Agglomerations facilitate the spread of the disease;
◦ Urbanization: Urbanized areas may offer less breeding sites for the vectors;
◦ Sanitation;
◦ Education;
◦ Migration: Introduction of infected hosts in non-endemic areas;
Individual/Family Household:◦ Housing condition;
◦ Water storage;
Community:◦ Type and abundance of public spaces/Land use:
Empty lots may offer breeding sites for the vectors
Arunachalam et al., 2009, FIOCRUZ, 2012
Vector controlLegislation:
◦ Water distribution and storage;
◦ Vector control policies;
◦ Waste disposal;
Control services:◦ Surveillance programs;
◦ Type, coverage and quality of control services;
◦ Human resources/efficiency/sustainability;
◦ Costs;
Stakeholders:
Arunachalam et al., 2009
ConclusionChikungunya disease is expanding thrououtthe world;
The spread of the disease depends on the distribution of its vectors;
The vectors are expanding geographicaly
The disease is related to lower socioeconomic status (disadvantadged populations), poor sanitation and agglomerations;
The disease is rarely fatal, but can impose a heavy burden on the health systems.
Setbon and Raude, 2008; FIOCRUZ, 2012
ReferencesPAHO, 2014 -http://www.paho.org/hq/index.php?option=com_content&view=article&id=8303&Itemid=40023&lang=en
CDC, 2014 (Map) -http://www.cdc.gov/chikungunya/pdfs/ChikungunyaWorld%20Map_11-04-2014.pdf
WHO, 2014 (Fact sheet) -http://www.cdc.gov/chikungunya/pdfs/ChikungunyaWorld%20Map_11-04-2014.pdf
Medlock et al., 2012 - A Review of the Invasive Mosquitoes in Europe: Ecology, Public Health Risks, and Control Options
Thiboutot et al., 2010. Chikungunya: A potentially emergingepidemic?
WHO, 2014. Epidemiological alert – Chikungunya and Dengue fever in the Americas
Tomasello D., Schlagenhauf P. Chikungunya and Dengue autocthonous cases in Europe, 2007-2012. Travel Medicine andInfectious Diseases, v. 11, pp. 274-284, 2013.
FIOCRUZ, 2012 -http://www.fiocruz.br/rededengue/cgi/cgilua.exe/sys/start.htm?infoid=134&sid=3
Arunachlam et al., 2009 - Eco-bio-social determinants of dengue vector breeding: a multicountry study in urban and periurbanAsia http://www.who.int/bulletin/volumes/88/3/09-067892/en/
Setbon M., Raude J. Chikungunya on Reunion Island: Social, Environmental and Behaviourial factors in na epidemic contexto. 2008
DeterminantsPoor sanitation;
Housing conditions;
Education;
Facilitate to proliferation of vectors.
Setbon and Raude (2008), analysing theChikungunya epidemic in La Réunion:
◦ Disadvataged categories are more affected;
Costa and Natal, 1998; FIOCRUZ, 2012.