Chikungunya Fever

Chikungunya fever is an acute arboviral illness transmitted by Aedes mosquitoes, characterized by sudden-onset high fever (>39°C) and debilitating symmetric polyarthralgia, with no specific antiviral treatment available. [1-3] The following figure illustrates the clinical timeline of infection, symptoms, and biomarkers:

• Onset and timing: Abrupt onset of high fever after an incubation period of 3–7 days (range 1–12 days); fever typically lasts ≤1 week and can be biphasic [2-3]
• Travel history: Essential — ask about travel to endemic areas (Southeast Asia, Indian subcontinent, sub-Saharan Africa, Caribbean, Latin America, Pacific Islands) within the prior 2 weeks [2]
• Arthralgia characterization: Severe, symmetric, bilateral polyarthralgia involving both large and small joints (hands, feet, wrists, ankles); pain so intense patients may be unable to move from the position they were in at onset [3]
• Associated symptoms: Maculopapular rash (trunk, extremities, palms/soles), myalgia, headache, conjunctivitis, nausea/vomiting, fatigue, anorexia [2-3]
• Important negatives: Absence of significant hemorrhagic manifestations, absence of thrombocytopenia, and absence of respiratory/GI symptoms help distinguish from dengue [4]

• Hemodynamic instability — hypotension, tachycardia, signs of shock [5]
• Neurological involvement — altered mental status, seizures, focal deficits (meningoencephalitis, Guillain-Barré syndrome, myelitis, cranial nerve palsies) [1-2]
• Cardiovascular decompensation — myocarditis, arrhythmias [1][5]
• Hemorrhagic signs — though rare in chikungunya, must exclude dengue coinfection [5]
• Respiratory failure, acute hepatitis, or acute renal failure [5]
• Severe bullous skin lesions (especially in children) [2]
• Neonates exposed intrapartum — risk of hemorrhagic symptoms, myocardial disease, neurologic disease [2]
• High-risk groups: Neonates, adults >65 years, patients with comorbidities (diabetes, heart disease, hypertension) — mortality risk increases 79-fold in those ≥60 years compared to 20–29-year-olds [2][6]

• First-line analgesia/antipyretic: Acetaminophen (paracetamol) — preferred until dengue is ruled out to avoid hemorrhagic risk; max 4 g/24 h, avoid in liver disease [2][5]
• NSAIDs: Can be used once dengue is excluded; effective for fever and joint pain. However, guidelines are contradictory — some advise caution due to risk of acute kidney injury and potential association with severe disease [5]
• Avoid aspirin/salicylates in the acute phase due to hemorrhage risk [5]
• Escalation for refractory pain: Tramadol, codeine, or opiates alone or in combination with paracetamol [5]
• Antihistamines: For pruritic rash (recommended by 39% of global guidelines) [5]
• Corticosteroids: Controversial in acute phase — some evidence of pain reduction when added to NSAIDs, but risk of rebound symptoms and immunosuppression; more accepted in subacute/chronic arthralgia [2][5]
• Chronic arthralgia: NSAIDs, corticosteroids, hydroxychloroquine, methotrexate, and physical therapy for persistent symptoms [2-3][7]
• No approved antivirals — ribavirin, favipiravir, and interferon-α have in vitro activity but no clinical evidence of efficacy [3][8-9]

• Hydration is critical — oral rehydration for mild cases; IV fluids for those unable to tolerate PO or with hemodynamic compromise [2][5]
• Rest — recommended during the acute febrile phase [2][5]
• Cold compresses to affected joints may provide symptomatic relief [5]
• No specific dietary triggers or restrictions; standard supportive nutrition during acute illness

• MSK: Joint pain/swelling (symmetric, bilateral), joint stiffness, periarticular edema, back pain
• Dermatologic: Maculopapular rash, pruritus, bullous lesions (children)
• Ophthalmologic: Conjunctivitis, eye pain (uveitis, retinitis in severe cases)
• Neurologic: Headache, altered sensorium, weakness, paresthesias
• Cardiovascular: Chest pain, palpitations, dyspnea
• GI: Nausea, vomiting, abdominal pain (less common than in dengue)
• Renal: Decreased urine output
• Constitutional: Intense fatigue, asthenia, anorexia

• Household contacts with similar symptoms (cluster outbreaks suggest local transmission)
• Co-travelers with febrile illness
• Mosquito exposure history — outdoor activities, lack of repellent/bed nets, standing water near residence
• Prior arboviral infections — previous dengue or Zika (affects serologic interpretation due to cross-reactivity)
• Pregnancy status — intrapartum transmission risk to neonate [2]
• Family history is generally not contributory, though comorbidities (diabetes, hypertension, cardiac disease) in the patient increase risk of severe disease [2][6]

• Travel to or residence in endemic areas (tropical/subtropical regions with Aedes mosquito populations) [1][5]
• Age extremes: Neonates and adults >65 years at highest risk for severe/atypical disease and death [2][6]
• Comorbidities: Diabetes, hypertension, cardiovascular disease, chronic kidney disease [2][6]
• Lack of prior immunity — naïve populations experience high attack rates; >85% of infected individuals are symptomatic [3]
• Rainy season/post-monsoon — peak mosquito breeding periods
• Urban settings with poor vector control [5]

The CDC recommends considering the following in the differential: [2]

• Dengue fever — more headache, retro-orbital pain, thrombocytopenia, leukopenia, hemorrhagic manifestations; less prominent arthralgia [4][10-11]
• Zika virus — lower-grade or absent fever, prominent pruritic rash, conjunctivitis; less arthralgia [11]
• Malaria — cyclical fevers, rigors, hepatosplenomegaly; thick/thin smear diagnostic
• Leptospirosis — conjunctival suffusion, jaundice, renal failure, exposure history
• Other alphaviruses — Mayaro, O'nyong-nyong, Ross River, Sindbis (similar arthritogenic presentation) [2][12]
• Measles/Rubella — rash characteristics, vaccination history, Koplik spots
• Parvovirus B19 — symmetric polyarthralgia, "slapped cheek" rash
• Reactive/postinfectious arthritis — temporal relationship to preceding infection
• Acute rheumatoid arthritis — chronic chikungunya can mimic RA [3]
• Group A Streptococcus, typhus, enteroviral disease [2]

Key distinguishing features of chikungunya: Debilitating polyarthralgia (PPV >80% for CHIKV viremia in endemic areas), absence of thrombocytopenia, joint swelling/edema, and rash — in contrast to dengue which features thrombocytopenia, leukopenia, and warning signs of plasma leak [3-4]

• Chronic conditions — diabetes, hypertension, heart disease, CKD increase risk of severe/atypical disease and death [2][6]
• Prior arboviral infections — affects serologic interpretation; prior CHIKV infection likely confers lifelong immunity
• Immunosuppression — may alter disease course
• Liver disease — relevant for acetaminophen dosing [5]
• Renal disease — caution with NSAIDs [5]
• Pregnancy — risk of intrapartum transmission; spontaneous abortion reported after first-trimester infection [2]

• Vitals: High fever (typically >39°C/102°F), tachycardia; hypotension is a red flag [2-3]
• MSK: Symmetric polyarthritis/polyarthralgia, periarticular edema (especially interphalangeal joints, wrists, ankles), tenderness along ligament insertions [3]
• Skin: Maculopapular rash on trunk and extremities (may involve palms, soles, face); can be bullous in children; pruritic [2-3]
• Eyes: Bilateral non-purulent conjunctivitis [1]
• Lymph nodes: Mild lymphadenopathy may be present
• Neuro: Assess for meningismus, focal deficits, altered consciousness (suggests atypical/severe disease)
• Cardiovascular: Assess for signs of myocarditis (new murmur, gallop, JVD)
• Tourniquet test: May help differentiate from dengue (more often positive in dengue)

• CBC: Lymphopenia is common; thrombocytopenia is typically mild or absent (in contrast to dengue where it is prominent) [2][4][13]
• CMP: Elevated creatinine and liver function tests (AST/ALT) may be seen [2]
• CRP/ESR: Elevated in acute phase
• Confirmatory testing:
  • RT-PCR (viral nucleic acid detection) — most useful in the first week of illness during viremia [2][7]
  • IgM serology — develops toward end of first week; can persist months to years; may cross-react with other alphaviruses [2]
  • IgG serology — appears 4–10 days after onset; persists for years [3]
  • Plaque reduction neutralization test (PRNT) — confirmatory, discriminates cross-reacting antibodies [2]
• Rule-out labs: Dengue NS1 antigen, dengue IgM/IgG, malaria smear, blood cultures if bacterial infection suspected

• Not routinely indicated in uncomplicated chikungunya
• Joint imaging (X-ray, ultrasound): Consider if chronic arthritis develops — may show periarticular soft tissue swelling; erosive changes can occur in chronic disease mimicking RA [3]
• Chest X-ray: If respiratory symptoms or suspected myocarditis/pulmonary edema
• CT/MRI brain: If neurological involvement suspected (encephalitis, myelitis)
• Echocardiography: If myocarditis suspected

• Clinical prediction rule for chikungunya (validated in dengue-endemic areas): Fever (1 pt) + exanthema (1 pt) + myalgia (2 pts) + arthralgia/arthritis (2 pts) + joint edema (2 pts); score ≥4 has 74% sensitivity and 52% specificity [14]
• Point-of-care rapid diagnostic tests: Chikungunya IgM rapid tests available in some settings
• Viral culture: Gold standard but impractical for clinical use; reserved for reference laboratories [7]
• Tourniquet test: Helps differentiate from dengue (more often positive in dengue)

• Indicated if: Chest pain, dyspnea, palpitations, or clinical suspicion of myocarditis
• Findings in myocarditis: ST-segment changes, T-wave inversions, conduction abnormalities, arrhythmias
• Routine ECG not required in uncomplicated cases
• Consider troponin and echocardiography if ECG abnormalities detected

Typical presentation: Abrupt-onset high fever with severe symmetric polyarthralgia, maculopapular rash, myalgia, and conjunctivitis in a patient with recent travel to an endemic area. Acute symptoms resolve in 7–10 days. [2]

Severity stratification

• Non-severe (majority): Self-limited febrile illness with polyarthralgia; manageable as outpatient
• Severe/atypical (rare): Organ involvement — myocarditis, encephalitis, hepatitis, renal failure, hemorrhage; requires hospitalization [5]

Chronic phase: 30–50% of patients develop persistent or relapsing polyarthralgia lasting months to years, which can mimic rheumatoid arthritis and cause significant disability [3][5]

Complications: Myocarditis, meningoencephalitis, Guillain-Barré syndrome, myelitis, uveitis/retinitis, acute hepatitis, renal failure, severe bullous lesions, neonatal disease from intrapartum transmission [1-2]

Initial stabilization (ED)

• ABCs; IV access if hemodynamically unstable or unable to tolerate PO
• IV fluid resuscitation for dehydration or shock [5]

Acute management

• Acetaminophen 500–1000 mg PO q6h (max 4 g/day) as first-line for fever and pain — preferred until dengue excluded [2][5]
• NSAIDs (ibuprofen, naproxen) once dengue ruled out — effective for arthralgia and inflammation [2][5]
• Tramadol or codeine for pain refractory to acetaminophen/NSAIDs [5]
• Antihistamines (cetirizine, diphenhydramine) for pruritic rash [5]
• Oral rehydration — encourage adequate fluid intake [2]
• Rest and cold compresses to affected joints [5]

Subacute/chronic arthralgia (>2 weeks)

• NSAIDs as mainstay
• Short-course corticosteroids (e.g., prednisone) with caution — risk of rebound [2][5]
• Physical therapy for persistent joint symptoms [2]
• Hydroxychloroquine or methotrexate for chronic inflammatory arthritis refractory to NSAIDs — used off-label with variable success [3][7]

Severe/atypical disease

• ICU admission for organ failure, hemodynamic instability
• IV fluids, vasopressors as needed
• Blood products for hemorrhage [5]
• Organ-specific supportive care (ventilatory support, renal replacement therapy)

Discharge criteria (majority of cases)

• Hemodynamically stable, tolerating PO fluids
• Pain controlled with oral analgesics
• No signs of severe/atypical disease
• Reliable follow-up and return precautions understood

Admission criteria: [5]

• Hemodynamic instability or signs of shock
• Atypical manifestations (neurologic, cardiac, hepatic, renal involvement)
• Severe pain unresponsive to oral analgesia
• Signs of hemorrhage
• Decompensation of underlying comorbidities
• Neonates with perinatal exposure
• Inability to tolerate oral intake / severe dehydration

Specialist consultation triggers

• Rheumatology — chronic/refractory arthralgia
• Infectious disease — diagnostic uncertainty, severe/atypical disease
• Neurology — encephalitis, GBS, myelitis
• Cardiology — suspected myocarditis
• Ophthalmology — uveitis, retinitis

Follow-up timing

• Primary care follow-up within 1–2 weeks for symptom reassessment
• Earlier if symptoms worsen or new symptoms develop
• Rheumatology referral if joint symptoms persist beyond 4–6 weeks

Return precautions — instruct patients to return immediately for:

• Worsening fever or new fever after initial resolution
• Bleeding (gums, nose, GI, vaginal)
• Severe abdominal pain, persistent vomiting
• Altered mental status, seizures, weakness
• Chest pain, shortness of breath
• Decreased urine output
• Inability to tolerate fluids

Patient counseling

• Acute symptoms typically resolve in 7–10 days [2]
• Joint pain may persist for weeks to months in up to 30–50% of patients — this is expected and does not indicate a new infection [5]
• Mosquito bite prevention during the first week of illness to prevent onward transmission (bed nets, repellent, long sleeves) [2]
• Report to local health department — chikungunya is a nationally notifiable disease [2]

1. Chikungunya: Epidemiology, Pathogenesis, Clinical Features, Management, and Prevention. — Vairo F, Haider N, Kock R, et al. Infectious Disease Clinics of North America. 2019.

2. Chikungunya. — J. Erin Staples, Susan L. Hills, and Ann M. Powers CDC Yellow Book. 2026.

3. Chikungunya Virus and the Global Spread of a Mosquito-Borne Disease. — Weaver SC, Lecuit M. The New England Journal of Medicine. 2015.

4. Distinguishing Patients With Laboratory-Confirmed Chikungunya From Dengue and Other Acute Febrile Illnesses, Puerto Rico, 2012-2015. — Alvarado LI, Lorenzi OD, Torres-Velásquez BC, et al. PLoS Neglected Tropical Diseases. 2019.

5. An Evaluation of Global Chikungunya Clinical Management Guidelines: A Systematic Review. — Webb E, Michelen M, Rigby I, et al. EClinicalMedicine. 2022.

6. Chikungunya Virus Virus-Like Particle Vaccine Safety and Immunogenicity in Adults Older Than 65 Years: A Phase 3, Randomised, Double-Blind, Placebo-Controlled Trial. — Tindale LC, Richardson JS, Anderson DM, et al. Lancet. 2025.

7. Chikungunya Infection: A Global Public Health Menace. — Mathew AJ, Ganapati A, Kabeerdoss J, et al. Current Allergy and Asthma Reports. 2017.

8. Chikungunya: A Re-Emerging Virus. — Burt FJ, Rolph MS, Rulli NE, Mahalingam S, Heise MT. Lancet. 2012.

9. Chikungunya Virus: An Update on the Biology and Pathogenesis of This Emerging Pathogen. — Burt FJ, Chen W, Miner JJ, et al. The Lancet. Infectious Diseases. 2017.

10. Symptom Overlap in Chikungunya and Dengue: A Diagnostic Challenge During Outbreaks. — Brancini ML, Sene FCT, Pereira Dos Santos TF, et al. Acta Tropica. 2026.

11. Comparison of Dengue, Chikungunya, and Zika Among Children in Nicaragua Across 18 Years: A Single-Centre, Prospective Cohort Study. — Carrillo FAB, Ojeda S, Sanchez N, et al. The Lancet. Child & Adolescent Health. 2025.

12. Arthritogenic Alphaviruses: Epidemiological and Clinical Perspective on Emerging Arboviruses. — Zaid A, Burt FJ, Liu X, et al. The Lancet. Infectious Diseases. 2021.

13. Comparison of Clinical Presentation and Out-Comes of Chikungunya and Dengue Virus Infections in Patients With Acute Undifferentiated Febrile Illness From the Sindh Region of Pakistan. — Shahid U, Farooqi JQ, Barr KL, et al. PLoS Neglected Tropical Diseases. 2020.

14. Development and Validation of a Clinical Rule for the Diagnosis of Chikungunya Fever in a Dengue-Endemic Area. — Batista RP, Hökerberg YHM, de Oliveira RVC, Lambert Passos SR. PloS One. 2023.