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.