รศ.พญ.ศิริลักษณ อนันตณัฐศิริสาขาวิชาโรคติดเชื้อและเวชศาสตรเขตรอน

ภาควิชาอายุรศาสตร คณะแพทยศาสตรมหาวิทยาลยัขอนแกน

ChikungunyaChikungunya virus

Arthropod-borne virus (arbovirus)Single-stranded, enveloped RNA virus genus Alphavirusfamily Togaviridae

VectorAedes spp. mosquitoes

Enzootic and Zoonotic disease

Lancet Infect Dis 2007; 7:319-27.J Gen Virol 2007; 88: 2363-2377.

Chikungunya Virus Genome

Non-structural proteins required for viral replication

Structural proteins • Cytoplasmic nucleocapsid protein• 2 major envelope surface glycoprotein (E1 & E2)• 2 small peptides (E3 & 6K)

J Gen Virol 2007; 88: 2363-2377.

J Gen Virol 2007; 88: 2363-2377.

Phylogenetic Analysis of ChikungunyaOutbreaks

J Gen Virol 2007; 88: 2363-2377.

Chikungunya transmission cycles

(A. taylori, A. africanus, A. furcifer )

(A. aegypti , A. albopictus )

African Chikungunya = rural, sylvatic cycle

Asian Chikungunya = urban, domestic cycle

J Gen Virol 2007; 88: 2363-2377

Clinical Presentations of ChikungunyaInfection

Incubation period2-10 days (usually 2-3 days)

Acute stage1-10 daysClinical triad: Fever, Rash, Rheumatic manifestations

Chronic stage5-10% of patientsSeveral weeks yearsRheumatic manifestations

Clinical Presentations of Acute Chikungunya Infection

Sign or symptoms No. of patients %Fever 296 100Joint pain 296 100Joint swelling 118 40Rash 83 28Back pain 123 42Headache 93 31Shoulder pain 57 19Retro-orbital pain 23 8Difficulty walking 17 6Polyarthritis 35 12Vomiting 12 4

Clin Infect Dis 2008; 46:1436-42.

Rash in Chikungunya Fever

Emerg Infect Dis 2006; 12:1565-7; Med Clin North Am 2008; 92: 1323-43; J Travel Med 2007; 14: 320-5.

Rheumatological Manifestations in Acute Stage of Chikungunya Fever

Weekly Epidemiol Surv Rep 2008; 39: 717-22.

Atypical Clinical Presentations of ChikungunyaFever

MyocarditisHemorrhagic manifestationsFulminant hepatitisNeurologic manifestations

MeningoencephalitisGuillain-Barré syndrome

Chronic Stage of Chikungunya Infection

Polyarthritis and tenosynovitis of wrists and

fingers

Hypertrophictenosynovitis

J Gen Virol 2007; 88: 2363-2377.

Chronic Stage of Chikungunya Infection

Bursitis

Med Clin North Am 2008; 92: 1323-43.

Chronic Stage of Chikungunya Infection

Raynaud’s phenomenonChronic swelling and stiffness of

the fingers with loss of grip strength

Med Clin North Am 2008; 92: 1323-43.

Differential Diagnosis of ChikungunyaFever

Dengue feverLeptospirosisRickettsiosesMalariaRubellaRheumatic fever

Alphaviruses causing Fever, Rash and Polyarthritis

O’Nyong Nyong virus Africa

Sindbis virus tropical Africa

Ross River virus Australia

Barmah Forest virus South Pacific

Mayaro virus South America

Clinical differences between Chikungunya and Dengue infection

Chikungunya Dengue FeverFever, asthenia Common CommonRash Days 1–4, important skin

edemaDays 3-7

Retro-orbital pain

Rare CommonMyalgia Possible Very commonPolyarthritis Very common, edematous NoneTenosynovitis Yes NoneHypotension Possible Common, days 5-

7Minor bleeding Possible CommonSecond stage •Chronic polyarthritis up to 1

year•Tenosynovitis at M2–M3•Raynaud’s syndrome at M2–M3

Fatigue up to 3 months

Med Clin North Am 2008; 92: 1323-43.

Laboratory differences between Chikungunya and Dengue infection

N (%)Laboratory finding Chikungunya

(22 cases)Dengue

(16 cases)

P

Leucopenia 8 (40) 12 (75) 0.033Neutropenia 2 (10) 13 (81) <0.001Lymphopenia 18 (90) 9 (56) 0.049Lymphocytosis 6 (30) 5 (31) NSAnemia 3 (15) 0 NSThrombocytopenia

7 (35) 14 (88) 0.002Increased ALT 13 (65) 14 (88) NSIncreased CRP 9 (64) 10 (77) NS

Am J Trop Med Hyg 2008; 78: 710-713.

Laboratory Diagnosis of Chikungunya Infection

Virus isolation RT-PCR techniqueSerologyELISA, neutralization test, hemagglutination inhibition

assay

Lancet Infect Dis 2007; 7:319-27.

RT-PCR Techniques for Diagnosis of Chikungunya Fever

Clin Infect Dis 2008; 46:1436-42.

Management of Chikungunya Infection

A non-fatal, self-limiting illness

No specific antiviral drug against chikungunya virus

Supportive careParacetamol is drug of choice for fever/pain.

Use of other analgesics/anti-inflammatory drugs if paracetamol does not provide relief; avoid aspirin, steroid

Rest during acute joint symptoms; cold compression

Mild exercise/physiotherapy are recommended in recovering persons.

Use hydroxychloroquine 200 mg or chloroquin phosphate 300 mg PO per day for 4 weeks in cases with refractory arthralgia to other drugs

Prevention and Control of Chikungunya Infection

No available vaccine for chikungunya

Patient/Community education

Minimize the vectorMinimize the vector--patient contact patient contact

Have the patient/other family members rest under bed-nets and wear full sleeves to cover extremities, preferably bright coloured clothes

Insecticide sprays

Wire-mesh/ nets on doors and windows

Prevention and Control of Chikungunya Infection

Patient/Community education

Minimizing vector populationMinimizing vector population

Remove stagnant water from all junk items lying around in the household and in the peri-domestic areas

Stagnating water in flower pots or similar containers should be changed daily or at least twice weekly.

Introduce larvivorous fish in aquaria, garden pools, etc.

Prevention and Control of Chikungunya Infection

Patient/Community educationMinimizing vector populationMinimizing vector population

Weeds and tall grasses should be cut short to minimize shady spaces where the adult insects hide and rest during hot daylight hoursDrain all water stagnating after rainsFogging and street sanitation with proper waste management in epidemic situation

แนวทางการเฝาระวังโรคไขปวดขอยุงลาย (Chikungunya)

แนวทางการเฝาระวังโรคไขปวดขอยุงลาย (Chikungunya)

แนวทางการเฝาระวังโรคไขปวดขอยุงลาย (Chikungunya)

แนวทางการเฝาระวังโรคไขปวดขอยุงลาย (Chikungunya)