Description

• Chikungunya virus (CHIKV) is an arthropod-borne virus (arbovirus) that causes a febrile illness (chikungunya fever) characterized by rash and arthralgia and arthritis of one or more joints.
• Arthralgia from CHIKV infection can last months to years and can be debilitating.

Epidemiology

• In the past decade, there have been explosive outbreaks of CHIKV infection occurring in Sub-Saharan Africa and Asia, followed by epidemics in South and Central America.
• During outbreaks, attack rates are high (80–90%).

Risk Factors

• Travel to or residing in an area with an active CHIKV outbreak
• Exposure to Aedes spp. mosquitoes
• Elderly (>65 years) individuals with underlying conditions have higher risks for more severe disease.
• Neonates born to CHIKV viremic women have high risk of infection and neuroinvasive disease.

General Prevention

• Mosquito avoidance
  • Wear clothing that maximizes skin coverage.
  • Use insect repellants such as N,N-Diethyl-meta-toluamide (DEET).
  • Cover crib, stroller, and baby carrier with mosquito netting.
• Empty open containers of standing water.
  • Stagnant water is a breeding ground for mosquitoes.
  • The Centers for Disease Control and Prevention (CDC) recommend emptying and scrubbing, turning over, covering or throwing out items that hold stagnant water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpots, or trash containers on a weekly basis.
• As of publication of this book in 2018, no vaccine exists to prevent CHIKV infection or disease.

Pathophysiology

Pathogenic mechanisms contributing to persistent arthritis/arthralgia remain poorly understood.

Etiology

• CHIKV is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Aedes mosquitoes are:
  • Endemic in many tropical and subtropical areas of the world
  • Highly adapted to thrive in peri-urban settings, often entering homes and laying eggs in man-made containers
  • Able to lay eggs in as little as a tablespoon of water
  • Expanding their habitat range due to global warming
• CHIKV is a member of the Alphaviridae family of arthritogenic viruses, including O’nyong nyong, Ross River, and Mayaro viruses.
  • Single-stranded RNA virus
  • First reported in 1952 to 1953 during an epidemic of fever, rash, and arthralgia in a region in present day Tanzania

Commonly Associated Conditions

Unknown