Yellow fever

Symptoms Of Yellow Fever

The first symptoms of yellow fever usually develop 3 to 6 days after being infected. They include: 

• Muscle pain and backache

• Feeling sick or vomiting

• Fatigue (feeling tired)

• General body aches

• Nausea

• Severe headache

• Eyes being sensitive to light

Most people with the initial symptoms improve within one week. For some people after recovery, weakness and fatigue (feeling tired) might last for several months. Yellow fever can be deadly among those who develop severe disease

Up to 1 in 4 people might develop a more severe form of the disease with symptoms such as:

• Yellowing of the skin and eyes (jaundice)

• Organ failure

• Bleeding from the mouth, nose, eyes, or ears

• High fever

• Shock

Don’t ignore any symptoms. Instead get tested. Lab tests are just a click away. 
Book Now!

Causes Of Yellow Fever

The yellow fever virus is an arbovirus of the flavivirus genus and is transmitted by mosquitoes, belonging to the Aedes and Haemogogus species. Different mosquito species live in different habitat: some lives in the wild, some are domestic and some in both habitat. There are 3 types of transmission cycles:

• Sylvatic (or jungle) yellow fever: In tropical rainforests, monkeys, which are the primary reservoir of yellow fever, are bitten by wild mosquitoes of the Aedes and Haemogogus species, they pass the virus on to other monkeys. The humans traveling in the forest are bitten by infected mosquitoes and later develop yellow fever.

• Intermediate yellow fever: During this type of transmission, semi-domestic mosquitoes (those that breed both in the wild and around households) infect both monkeys and people. Increased contact between people and infected mosquitoes leads to increased transmission. This is the most common type of outbreak in Africa.

• Urban yellow fever: Large epidemics occur when infected people introduce the virus into heavily populated areas with a high density of Aedes aegypti mosquitoes and where most people have little or no immunity, due to lack of vaccination or prior exposure to yellow fever.

Risk Factors For Yellow Fever 

1. Being unvaccinated

Unvaccinated young children are prone to yellow fever and its complications including death. Unvaccinated pregnant women and nonimmune people can become infected. 

2. International traveling 

Traveling to countries where yellow fever is common and less controlled puts you at a higher risk of developing the disease. 

3. Countries experiencing a yellow fever outbreak 

Countries experiencing or recovering from a natural disaster. Damage to health infrastructures interrupts routine immunization and greatly increases the risk of infection. 

Diagnosis Of Yellow Fever 

Yellow fever is difficult to diagnose, especially during its early stages. A more severe case can be confused with severe malaria, leptospirosis, viral hepatitis, other hemorrhagic fevers, and infection with other flaviviruses (such as dengue hemorrhagic fever). 

1. History and physical examination 

The diagnosis requires a thorough travel history and record of immunization. The doctor may evaluate the present symptoms such as headache, malaise, jaundice, and myalgias with severe back pain. The incubation period of the virus is usually 3-7 days, with most individuals having a mild flu-like illness. In severe 15% of cases, symptoms include chills, low back pain, headache, and fever. During the physical examination, the doctor may check the Faget sign or pulse fever dissociation, facial flushing, and conjunctival injection. During the most toxic phase, patients develop jaundice, dark urine, and vomiting. Bleeding may occur from mucous membranes and in the gastrointestinal tract.

2. Lab tests 

Laboratory confirmation is important after the physical evaluation is done by the doctor. 

• Antigen detection: Rapid detection methods include the detection of yellow fever antigen using a monoclonal enzyme immunoassay in serum specimens.It is accomplished by testing serum to detect virus-specific IgM and neutralizing antibodies. 

• Polymerase chain reaction: This improved technique not only ensures the specific detection of a wide range of yellow fever virus genotypes but also may increase the sensitivity of detection. 

• Enzyme-linked immunosorbent assay (ELISA): This is a common test that is able to detect different types of antibodies produced at different stages of the infection. This test  uses the binding of antibodies to antigens to identify and measure certain substances. 

3. Other tests 

• Lumbar puncture: In case of altered mentation, a lumbar puncture is performed. A lumbar puncture is sometimes called a cerebrospinal tap a medical procedure that can involve collecting a sample of cerebrospinal fluid (CSF). 

• Computed tomography (CT) scan: A CT scan uses computers and rotating X-ray machines to create cross-sectional images of the body. In case the brain is involved in yellow fever, a CT scan is performed. 

• Liver function tests (LFT): If the liver is involved, the coagulation profile may be abnormal. 

• Chest X-ray: A chest x-ray is done in patients with respiratory distress because of pulmonary edema.

• Electrocardiograph (ECG): This test is performed in case of prolonged QT and PR intervals. Arrhythmias are common when the myocardium is affected.

• Complete blood count (CBC): The blood test may also show a reduction in the number of infection-fighting white blood cells (leucopenia). This can occur because the yellow fever virus affects bone marrow (the spongy material at the center of some bones that produces blood cells).

Specialist To Visit

Patients exhibiting the signs and symptoms of yellow fever should visit a general physician. If needed, your doctor may recommend you to go to a specialist such as:

• Infectious disease specialist: A doctor who is trained in internal medicine and specializes in diagnosing, treating, and managing infectious diseases.

• Pediatrician: A pediatrician is a children’s specialist who diagnoses and treats malignancies, infections, and genetic defects.

Consult India’s best doctors online with a single click.
Consult Now!

Prevention Of Yellow Fever 

The most effective way to prevent infection from yellow fever virus is to prevent mosquito bites. Mosquitoes bite during the day and night. 

Vector control

This can be done by using insect repellants, wearing long sleeves shirts and pants, stopping mosquito breeding both indoors and outdoors by avoiding water lodging, and preventing mosquito bites while traveling overseas.

Have you tried these latest range of mosquito repellants like mosquito repellent bands, patches and more? If not, have a look!
Check Out!

Vaccination 

Yellow fever can be prevented by taking vaccination against it. A single injection of yellow fever vaccine given subcutaneously provides immunity to 100% of its recipients. The vaccine provides immunity only after 10 days of vaccination. However, a booster dose is required every ten years by persons residing in nonendemic countries. A further dose of vaccine is recommended for a small number of travelers who are visiting yellow fever risk areas, including those who were previously vaccinated when they were:

• Pregnant

• Under 2 years old

• Living with HIV

• Had a weakened immune system

There are some groups of people who cannot have the yellow fever vaccine when it's recommended include: 

• People whose immune system is weakened by treatment, such as steroids and chemotherapy

• People who had a severe reaction to a previous dose of yellow fever vaccine

• People with a thymus gland disorder or who've had their thymus gland removed

Epidemic preparedness and response

Prompt detection of yellow fever and rapid response through emergency vaccination campaigns are essential for controlling outbreaks. A confirmed case of yellow fever in an unvaccinated population is considered an outbreak. A confirmed case in any context must be fully investigated. 

Treatment Of Yellow Fever 

There is no specific treatment, but severe cases require aggressive supportive care and hydration can be helpful in getting relief:

• Rest, drink fluids, and use pain relievers and medication to reduce fever and relieve aching.

• Avoid certain medications, such as aspirin or other nonsteroidal anti-inflammatory drugs, like ibuprofen or naproxen which may increase the risk of bleeding.

• People with severe symptoms of yellow fever infection should be hospitalized for close observation and supportive care.

• People with yellow fever should be protected from further mosquito exposure (for example, they should stay indoors or under a mosquito net) during the first few days of illness, so they do not contribute to the disease transmission cycle.

• Paracetamol and ibuprofen can be taken for controlling fever and the pain caused by the virus, for children liquid paracetamol can be used. 

• If a person is having a high temperature increase the intake of fluids to eliminate the risk of dehydration. 

Home-care For Yellow Fever 

No specific treatment exists for yellow fever, which is one reason that preventative measures such as vaccination are so important. Supportive treatment is aimed at controlling the symptoms and includes rest, fluids, and the use of medicines to help relieve fever and aching.

There is no specific home care treatment for yellow fever. The patient requires care and time to time medicines and few precautions. Home care is to be taken to make the disease tolerable:

• Get plenty of rest

• A sponge bath can reduce discomfort due to fever

• Drink plenty of water 

• Pain relievers and analgesics such as acetaminophen

• To reduce itching from the rash, one can use witch hazel on the rashes or add oatmeal to a bath

• Talking with a doctor openly in case of any questions related to the disease 

• Taking adequate sleep

Dietary modifications

• Drink a minimum of 8 glasses of water daily.

• Avoid refined foods, such as white bread, pasta, and sugar.

• Use healthy oils in cooking, such as olive oil, coconut oil, or ghee.

• Reduce or eliminate trans fats found in processed and packaged foods like biscuits, namkeens, and cakes.

• Limit caffeine-containing beverages like coffee. Avoid alcohol and tobacco.

Alternative Therapies For Yellow Fever 

Home remedies 

The following home remedies can help in recovery from yellow fever:

• Garlic (Lehsun): It is known for its anti-inflammatory property; and thus, very good medicine for a mosquito bite.

• Tomato (Tamatar): They have a good source of water content and thus provide enough water to the body. It helps in getting relief in nausea or vomiting caused due to yellow fever.

• Coconut water (Nariyal pani): It is the best supplement for yellow fever, as it has the ability to turn yellow eyes to normal.

• Watermelon (Tarbuz): It has cooling properties, a great substitute for water loss in the body due to nausea or vomiting or appetite loss that appears during yellow fever. 

• Bitter gourd (Karela): It is the best method for reducing inflammation. It is advisable to drink at least two tablespoons of bitter gourd juice, twice a day.