Pedro Fernando C....

Pedro Fernando C. VasconcelosInstituto Evandro Chagas, SVS/MS

Centro Colaborador OPAS/OMS em Arbovírus

INCT para Febres Hemorrágicas Virais

Laboratório de Referênciia Nacional de Arbovírus

Ananindeua, Pará State, Brazil

[email protected]

Laboratory diagnosis to Chikungunya virus infections

Chikungunya Virus

• Family Togaviridae, genus Alphavirus• Enveloped, single stranded RNA virus

• Plus-sense, unsegmented genome of 11.5-11.8 kilobases

• First isolated from human

serum during outbreak in

Tanganyika - 1953

• Distinct biological and

transmission patterns between

African and Asian strains

Classical clinical presentationFever

Severe joint pain

Rash (maculopapular)

Phylogenetic Tree of Alphaviruses

Période d’incubation 2

( 5 à 7 jours)

Cycle extrinsèque

chez le moustique

(10 jours)

Virémie= Période à risque de

contamination d'un moustique

5-7 joursPériode d’incubation 1

(5 à 7jours)

Arrivée d’une personne

infectée, en début

d’incubation

Survenue d’un cas

secondaire

Début des signes cliniquesContamination secondaire d’une

personne résidant en Martinique

Risk of introduction and dissemination of

Chikungunya virus

Chikungunya no continente americano:

Até 15/08/2014: 585.798 casos, 37 fatais

ChikungunyaFever in Brazil

More than 600 suspect cases

~60 importaed cases

The majority of notified cases were people coming from Haiti and

diagnosed in São Paulo State;

Cases were also reported in AM, PA, RR, CE, PE, MG, GO, DF, PR

and RS;

41 autocthonous cases

15 cases from Oiapoque (Amapá State)

26 cases from Feira de Santana (Bahia State)

23 under investigation (16 BA; 4 RR; 3 PA)

Transmission by the Aedes aegypti mosquitoes;

All cases were classic Chikungunya fever;

The nucleotide sequencing followed by phylogeny of two imported cases and

another of local transmission showed the Asian genotype was responsible for

transmission in Brazil; the same genotype occurring in the Caribbean region.

Chikungunya Virus

Diagnostic Assays

DAYS POST ONSET

1 2 3 4 5 6 7 8 9 10-14 to -2 0

IgM

IgG

ELISA

P/N#pfu/ml106

Simplified Depiction of CHIK Human Viremia & Immune Response

2

20

Neutralizing Ab

CHIKviremia

Current Laboratory Testing Strategy

for CHIKV and other Arboviruses• Human Infection

– Acute antibody (IgM) in serum and/or csf.

• IgM ELISA or Microsphere Immunoassay

• Confirmation by PRNT

– Seroconversion in paired specimens by

• IgG ELISA, HI and/or 4-fold rise in neutralizing antibody by PRNT

– Detection of virus and/or viral RNA in serum and/or csf.

• Real time RT-PCR, Consensus RT-PCR, or virus isolation

• Environmental Surveillance

– Detection of virus and/or viral RNA in mosquito vectors or amplifying hosts.

• Real time RT-PCR, Consensus RT-PCR, or virus isolation

IgM Cross-Reactivity of Human CHIK

Cases With Other Alphaviruses

CHIK IgM Capture ELISA (P/N)

CHIK RR ONN VEE MAY EEE

12.3 1.5 15.3 0.89 1.9 1.2

10.6 1.2 13.9 1.1 1.9 1.3

14.5 1.7 17.3 1.1 3.1 0.89

20.4 0.92 20.7 1.5 7.1 1.8

26.6 4.9 27.4 2.2 1.7 1.5

21.2 1.5 24.7 2.2 1.2 1.6

15.3 1.5 8 1.6 1.9 2.2

31.3 1.5 24.6 1.7 2.9 1.8

22 1.6 15.9 1.8 1.4 1.4

18.8 0.59 13.1 1.2 1.5 1.1

34.3 3.7 22.6 1.6 2.8 9.1

CDC CHIK Real-Time RT-PCR Assay

• Developed 4 primer/probe sets

• Detects all CHIK genotypes (WA, SCEA, & Asia)

• Analytical sensitivity; 25 copies/reaction

Genetic Lineages of Chikungunya Virus

• Chikungunya virus is within the Semliki Forest Virus complex.

• Chikungunya virus is genetically classified into 3 clusters;

– Asian, West African, and Central/South/East African.

– 2006 Indian Ocean epidemic caused by CHIK virus from the CSEA cluster.

- 2014 American continent epidemic is caused by CHIKV Asian genotype

Serological Testing Algorithm

for Chikungunya Virus Infection

single acute

patient serum

IgM Capture ELISA

IgG ELISA

RT-PCR (<10day)

IgM POS

PRNT

IgM NEG

(<10day)

No

Interpretation

IgM NEG

(>10day)

NEG

RT-PCR or

Isolation POS

POSPOS

Environmental Testing Algorithm

for Chikungunya Virus Detection

Mosquito

pool

Real-time RT-PCR

Consensus RT-PCR &Nucleic acid sequencing

Virus isolation

CHIK Case Definition

• Laboratory evidence of an acute CHIKV

infection

1. Detection of CHIK viral RNA or virus, or

2. Detection of anti-CHIKV IgM antibodies (Ab), or

3. Four-fold increase in neutralizing Ab titers

between acute and convalescent samples

Distribuição dos Casos Importados de Chikungunya por Estado no Brasil segundo a Procedência

1 12

15

2 2

41

1

1

1

1

1

Amapá

Ceará

Distrito Federal

Góias

Maranhão

Pará

Paraná

São Paulo

Rio de Janeiro

Rio G

rande do Sul

0

2

4

6

8

10

12

14

16

Haiti

Rep. Dominicana

Guiana Francesa

Guadalupe

Comments• Chikungunya virus represents a serious concern to

Brazil and other dengue endemic countries due to:

– Presence of both vectors in high density levels

– Completely naïve population to CHIKV living in country

– Increase in the international travel to/from the CHIKV endemic/epidemic countries

– Disease is completely unknown to Brazilian physicians

– Several diseases, mainly viral, mimic CHIK fever

– Limited laboratory capacity to confirm CHIKV infection

CHIK GUIDELINES LINKS

• Guidelines for Prevention and Control of Chikungunya fever (SEARO/WHO)

http://www.searo.who.int/LinkFiles/Chikungunya_SEA-CD-182.pdf

• Guidelines on Clinical Management of Chikungunya fever (SEARO/WHO)

http://www.searo.who.int/LinkFiles/Publication_guidelines_on_cli_mgmt_chikungunya_fvr-(cd-180).pdf

• Mission Report, Italy CHIK Outbreak. Joint ECDC/WHO visit for a European risk assessment

http://www.afpmb.org/bulletin/vol27/071020_CHK_report.pdf

• Programme de surveillance, d’alerte et de gestion du risque d’émergence du virus Chikungunya dans les départements français d’Amérique

http://www.martinique.sante.gouv.fr/documents/accueil/cire/chikungunya/prog_action_anti_chik.pdf

Acknowledgements

CDC PAHO

Ann Powers Otávio Oliva

Barbara Johnson

Roger Nasci IEC

Rob Lanciotti Sueli G. Rodrigues

Guajará Bay and Ver-o-peso Market, Belém

IV Simpósio Pan Americano de Pesquisa em Dengue, Belém, Pará, Brasil,

19-23/10/2014

INSTITUTO EVANDRO CHAGAS1936-2011

[email protected]

New Campus of Instituto Evandro Chagas in Ananindeua/Pará.

Arbovirology and Hemorrhagic FeversINSTITUTO EVANDRO CHAGAS1936-2011



Arbovirology and Hemorrhagic Fevers













www.iec.pa.gov.br

Obrigado!




[email protected]




Pedro Fernando C....

Documents

Transcript of Pedro Fernando C....