Introduction

Chikungunya ( CHIKV) is a mosquito-borne viral disease, spread by the bite of a CHIKV virus-infected mosquito, affecting people of all ages and genders. The symptoms of the virus show up after 2-3 days of the mosquito bite.

Currently, there is no targeted cure for treating chikungunya. Most commonly used medicines are used to treat the symptoms, and some antiviral medications are also used after proper diagnosis. And currently, vaccines are underdeveloped. Therefore, management and prevention of this viral disease is important.

Transmission and epidemiology 

Chikungunya virus is mostly found in tropical regions, affecting major countries of continents like Africa, Asia, Central & South America, and Europe. 

The virus is transmitted through a CHIKV-infected mosquito, known as a vector or carrier bite to a human. Mosquitoes belonging to the species Aedes aegypti and Albopichtus are known vectors causing the viral infection. Chikungunya is a non-communicable disease that doesn't spread by being in contact with an infected person, but in rare cases, infection through blood transmission is possible.¹

In 2018, WHO included CHIKV in the list of priority R&D and it is also one of the pathogens that needs immediate vaccine development.²

Symptoms of chikungunya infection

The most common symptoms of CHIKV are fever and joint pains, which can be seen after 2 days of mosquito bite or after 10 days. The symptoms generally last for a week and can be treated using painkillers. Other symptoms include headache, muscle pain, swelling in joints, fatigue, rash, and nausea.¹ Half of the patients infected get better in months after suffering acute symptoms.²

Complications due to chikungunya are rare and non-fatal, although some people can develop chronic joint pain that can last up to years. Newborns, older people, and adults with chronic medical conditions like diabetes and hypertension are at risk.¹

Current treatment options

Symptomatic treatments 

Pain relief medications (e.g., NSAIDs, acetaminophen)

Since there is no particular medicine for chikunya treatment, the most common way to treat the disease is by controlling the symptoms. Generally, a person is advised to use paracetamol and acetaminophen, which are painkillers. 

Other medicines called nonsteroidal anti-inflammatory drugs ( NSAIDs) are used, but need to be consulted by a certified doctor before use. They are also used in combination with primary medicines to prevent resistance and ineffectiveness of NSAIDs.

During the early stage of the disease, it is recommended to drink plenty of fluids and take proper rest to prevent fatigue and dehydration.¹

Antiviral medications

Unfortunately, there are no approved anti-viral medicines, treatments used are based on prevention, symptom management, and the use of anti-viral compounds that have shown effectiveness against virus disease.³

Some of the anti-viral compounds that have properties against CHIKV are favipiravir, ribavirin, and glycyrrhizin. Harringtonine, which is also an anti-viral compound reduces the viral protein in the in-vitro study and needs further testing.

There are some anti-viral drugs under the clinical phase and development process, which can soon become treatment strategies.

Experimental treatments

Immunotherapies

Immunotherapy involves antibodies fighting against viruses and infections. For the treatment of CHIKV, human polyclonal antibodies (CHIKV Ig) are extracted and purified from the plasma of donors that already suffered the infection and developed antibodies. The Ig was then inserted in an infected mouse that showed positive results in prevention and therapeutic effects against CHIKV. When a person is infected with the CHIKV virus, the body’s immune system develops antibodies against the virus, so the chances of a second infection are rare, and if the person gets infected, it will be treated in a few days.

Immunotherapy is useful in preventing the transmission between the birth parent and newborn and an outbreak.⁴

Vaccines in development

Several preventive vaccines will soon be available for public use and some are currently going through clinical trials.³

In 2023, the FDA approved the use of vaccine IXCHIQ in the U.S for people above age 18 and are traveling to countries of the chikungunya outbreak.¹ Another vaccine BBV87 based on the Indian CHIKV variant is set to undergo a phase 2 trial, this vaccine if successful will be a promising therapy.²

There is need for a vaccine that can be used against all viral variants and it needs further research and data on all variant species present in the world.

Effectiveness of treatment options

For the treatment of pain resulting from acute symptoms, medications like paracetamol and codeine are recommended. Inflammatory medicines including NSAIDs like ibuprofen, naproxen, and aceclofenac are used under doctor’s prescriptions.

Chronic pain is treated using corticosteroids along with paracetamol and codeine.²

The success of antiviral medications 

Since there are no official anti-viral drugs for chikungunya, various anti-viral compounds are being studied and undergoing clinical trials.

The pros and cons of the compounds are mentioned below:

• Chloroquine – these are anti-malarial compounds, also used as treatment drugs for viral disease. This compound had a successful in-vitro trial but needs an in-vivo trial
• Ribavirin– they have the property of healing joint tissues but need to be tested on a large scale of patients
• 6-aziridine – its in-vitro study showed inhibition of CHIKV but it requires a human trial⁴
• Harringtonine – it has inhibiting properties against viral RNA but requires in-vivo trial data

Preventive measures

Prevention is always better than cure. Similarly, in chikungunya disease, there are some preventive measures advised to everyone, especially during an outbreak or rainy season. These are:

• Use of insect repellent: before use, check the instructions and caution
• Wear full clothes to prevent mosquito bites
• Use of repellent sprays that can be used on clothes and the body
• Remove still water around your home that is collected during rain because mosquitoes lay eggs near still waters
• Insert mosquito screens on doors and windows
• Avoid traveling to places with an outbreak 

People who are already infected with the chikungunya virus need to be prevented from another mosquito bite, because they can infect the uninfected, thus leading to a chance of spreading.¹

FAQs

How is chikungunya virus diagnosed?

Diagnosis is done by three methods - virus isolation, serological test, and antibody test.

A serological test involves RT-PCR and ELISA based on the onset of disease. During the early phase, RT-PCR is done by testing the serum of infected individuals. 

In the antibody test, the body generates IgM antibodies against the virus that is isolated and tested. 

What are some foods to consume and avoid during the infection?

Foods to consume should generally be rich in minerals and blood-forming compounds. A diet consisting of green leafy vegetables, seasonal fruits, herbs, vegetable soup, and foods rich in omega-3 is recommended.

Foods to avoid are processed, unhealthy, and greasy foods. Avoid alcohol and smoking, non-vegetarian food, and limit the amount of caffeine intake.

What is the origin of the name “chikungunya”?

Chikungunya was first reported in Tanzania and in the language kimakonde used in the country, the word chikungunya means “to bend” or “to stoop”. Since the symptom of this viral disease is joint pains, the body bends in an abnormal position, therefore suggesting the name.

Summary

Chikungunya is an alphavirus vector-borne disease, present in tropical and subtropical climatic regions, that primarily causes fever above 39 °C and joint pains that can rarely develop in long-term chronic arthritis. The virus is found in all continents, mostly in forests but in the past few decades, urban transmission has significantly increased, making chikungunya a global threat. The infection spreads when a chikungunya-infected female mosquito bites a healthy person releasing the virus into the human's bloodstream. People above 65 and people with health conditions are at more risk of chronic symptoms. Unfortunately, there are no approved anti-viral medications and vaccines yet, therefore, treatment is mostly symptomatic control. 

An early phase of chikungunya can be treated at home for 15-20 days by using painkillers, consuming fluids, and resting. The acute chikungunya symptoms get better in a month. If by any chance, the joint pain persists, the person must undergo further treatment that includes anti-viral compounds, immunotherapy, and vaccines under trial. There is a list of anti-viral medications that have shown effectiveness in the control of a disease that can be a future drug for CHIKV. Many vaccines under trial have promising results against the alphavirus. Soon, there should be a chance of anti-viral and vaccine development for market use. Management of the chikungunya virus is important and many national and international authorities provide guidelines to prevent vector exposure.