CHIKUNGUNYA

CHIKUNGUNYA

SYNONIM
• Fever CHIKV
• Buggy Creek virus infection
• Knuckle fever
• Me Tri virus infection
• Semliki Forest virus infection

HISTORY AND EPIDEMIOLOGY

• Infection Chikungunya Virus (CHIKV) was first reported → Africa → 1952-53 East
• M. Robinson and WHR Lumsden in 1955 → Dengue-like fever
• "Chikungunya" →  Makonde language "that roomates bends up" → posture is formed due to the symptoms of the disease arthritis
• • Most cases of Africa and India →

• AFRICA
Benin, Burundi, Cameroon, Central African
Republic, Kenya, Uganda, Malawi, Senegal,
Congo, Nigeria, Sudan, Guinea, South Africa,
Tanzania, Zimbabwe, Namibia, Comoros,
Mayotte, Ghana, Burkina Faso, Mozambique, and
Gabon

• ASIA
India, Sri Lanka, Myanmar, Thailand,
Vietnam, Taiwan, Singapore, Cambodia,
Pakistan, Laos, Philippines, Malaysia,
Indonesia, and East Timor

STRUCTURE. GENOME CHIKV

1. Arthropod-borne viruses (arboviruses)
2. alphavirus genus: 50-70 nm icosahedral shape that is surrounded by contain virus envelope glycoprotein
3. Nukleocapsid contains complex single strain RNA genome of 11.8 kb
4. Virion envelope consists of a lipid bilayer derived from the host cell that contains two major glycoproteins E1 and E2 viral coding
5. E1 and E2 has a molecular mass of 50 kDa and stick pd membrane at the C-terminal region

TRANSMISSION
• Reservoir - Non-human Primates in Africa
• Maintained in nature by man - mosquito - man cycle
• Vector - Aedes aegypti, Ae. albapticus mosquito
• Same as the vector for Dengue and Yellow fevers
• No known mode - other than mosquito bite
• Incubation Period - 2 days to 12 days

THE VECTOR

CYCLE TRANSMISSION CHIKV

Clinical manifestations

• Sudden high fever, rash, joint pain
• Typical symptoms are joint pain got 100% in all patients
• Pain improved in a week, but some reported cases months or even years in the form of frequent relapses
• pathogenesis is still not entirely clear
• A variety of cells can be infected (epithelial, endothelial, fibroblasts, macrophages)
• Instead lymphocytes B, T and monocyte-derived dendritic cells (DC) are not involved in viral replication
• Imunohistologi of muscle biopsy px CHIKV infected with myositis syndrome showed the presence of viral antigen in muscle progenitor cells (cells satellite) and not in the muscle fibers
• Because these cells are the main cells in the growth and recurrent myalgia muscle healing →
• The severity of the infection depends on the age of the patient and the function of INF type I signal system
• Ng et al → predominansi circulation of type 2 cytokines, especially IL-5, IL-6 and IL-10 in acute CHIKV infection, and the slow response anti inflammatory during infection (when the virus is eliminated from the blood)

Symptoms
Sudden onset of fever, chills
Headache, nausea, vomiting, abdominal pain
Fever (92%) usually associated with
• arthralgia (87%),
• Backache (67%) and
• Headache (62%).
Very similar to those of Dengue Hemorrhagic but Unlike in, no
hemorrhagic or shock syndrome

OTHER CLINICAL SYMPTOMS

JOINT INVOLMENT

CHIK VS DENGUE

   











DIAGNOSIS

1. Isolation of virus from cell culture
2. Detection of viral RNA by RT-PCR from serum
3. Evaluate response thd CHIKV specific antibodies (Ig M and Ig G)

• Ig M was detected in 2-6 days from symptom onset (ELISA and IIF) and last up to several weeks to three months)
• Ig G was detected in serum at the convalescent stage and lasted until the several years → high sensitivity but lack specificity due to cross-reactive antigen with other Arbovirus

Need confirmation by plaque neutralization test test (Prnt)

DIFFERENTIAL DIAGNOSIS

• Leptospirosis
• Dengue fever, DHF, DSS
• Malaria.
• Rheumatic fever

CHIK VS DENGUE INFECTION

MANAGEMENT
• There is no specific therapy
• Treatment is intended to address complaints: analgesic agent,
antipyretic and anti-inflammatory agent is a major
• Chronic arthritis who do not respond to NSAID → chloroquine
phosphate
• RNAi → new strategy to fight viral infections

VACCINATION

• There is currently no commercial vaccine for CHIKV yet some vaccines are being developed
• Harrison et al → vaccine of inactivated cell culture
• Edelman et al → attenuated vaccine by serial passages of CHIKV in an MRC-5 cell line → highly immunogenic and well tolerated → phase II trial: satisfactory seroconversion rates (98% on day 28) with a neutralization titer antibodies and persist in 85% of cases were evaluated at 1 year then

CHIKV INFECTION IN ITALY: THE SPREAD OF NEW REGIONAL

• Indian Ocean Islands Outbreak → number of infected traveler → back to their respective countries in the deployment of new areas
• Italy → national infectious diseases surveillance system (2007) → 22 traveler who returned with symptomatic and → epidemic CHIKV positive serum outbreak
• New cases can → vector control (synergised pyrethrumcompounds insectiside, insect growth regulators and Bacillus thuringiensis var. israeliensis, and eliminate where growth vector)

CONCLUTION AND FUTURE DIRECTION

• Difficulty controlling and preventing the spread of vector traveling to and from endemic areas → Plan for Chikungunya and dengue:

         - Early detection of suspected cases of infected
         - Environmental control (surveillance to count larvae, larvicidal
           Periodically, adulticide of mature mosquitoes)