Yellow fever

Yellow fever

Yellow fever is a disease caused by a virus and is transmitted through mosquitoes. Yellow fever is characterized by high fever, and yellowing of the eyes and skin due to decreased liver function.

Yellow fever or  yellow fever  is a dangerous disease. If not treated properly, this condition is at high risk for serious complications, such as kidney failure and  coma . In some cases, yellow fever can even cause death.

Causes of Yellow Fever

Yellow fever is commonly found in Africa, South America, Central America, and the Caribbean. Yellow fever can also affect people who live in endemic areas, or people who are visiting these areas.

Yellow fever is caused by a virus of the  flavivirus type  which is spread by the mosquitoes Aedes aegypti , Aedes albopictus , Haemagogus sp., and Sabethes sp. This type of mosquito breeds in the environment around humans, including in clean water.

The Aedes aegypti mosquito carries   the virus after biting an infected human or monkey. The virus then enters the mosquito's bloodstream and settles in the mosquito's salivary glands.

When the mosquito bites another human or monkey again, the virus will enter the bloodstream and spread within the human or monkey's body.

The Aedes aegypti mosquito is  most active during the day. Therefore, the spread of the yellow fever virus is most prevalent at that time.

Symptoms of Yellow Fever

Symptoms of yellow fever appear in three phases, namely the incubation, acute, and toxic phases. Here's the explanation:

1. Incubation phase

In this phase, the virus that enters the body has not yet caused signs or symptoms. The incubation phase lasts 3–6 days after infection.

2. Acute phase

This phase occurs on the 3rd or 4th day after infection, and can last for 3–4 days. In this phase, people with yellow fever begin to feel symptoms, such as:

  • Fever
  • Shivering
  • Dizzy
  • Muscle ache
  • Headache
  • Redness in the eyes, face, or tongue
  • Glare against light
  • Loss of appetite
  • Nausea and vomiting
  • Tired easily

After the acute phase ends, these symptoms will disappear. Most people recover from yellow fever after this phase. However, as many as 15-25% of patients will actually enter a more serious phase of yellow fever, namely the toxic phase.

3. Toxic phase

In this phase, the symptoms that appear during the acute phase will be felt again by the sufferer after 24 hours of not appearing. Symptoms in the acute phase are accompanied by more serious complaints, such as:

  • Yellowing of the skin and the whites of the eyes (sclera).
  • Bleeding from nose, mouth and eyes
  • Vomiting sometimes accompanied by blood
  • Heart rhythm disturbances ( arrhythmias )
  • Little urine comes out
  • Stomach ache
  • Kidney failure
  • heart failure
  • Shock
  • Brain disorders, including  delirium , seizures, to coma

When to see a doctor

Check with your doctor before you visit an area that is known to have had or is experiencing an outbreak of yellow fever. This is to determine whether you need to get vaccinated for yellow fever or not.

It is recommended that vaccination be carried out 3-4 weeks before traveling. However, if you don't have enough time, discuss with your doctor whether vaccinations should still be done, and ask for other recommendations so you can travel safely.

Immediately see a doctor when you feel the symptoms of yellow fever as mentioned above, especially if you are on or after visiting endemic countries.

Yellow Fever Diagnosis

The following are attempts by doctors to diagnose yellow fever:

  • Asking questions regarding the patient's history of symptoms, including travel history to other areas and medical history
  • Perform a complete physical examination from head to toe, including checking body temperature and blood pressure
  • Do a blood test to find out whether there is a virus in the blood, or to detect antibodies that appear when the body is infected with a virus

Yellow fever is sometimes difficult to diagnose because the symptoms are quite common and resemble those of other diseases, such as malaria , typhus , and  dengue fever .

Treatment of Yellow Fever

There is no medicine that can cure yellow fever apart from the immune system of each sufferer. Nevertheless, there are several treatment methods that doctors can do to treat symptoms, namely:

  • Provide supplemental oxygen
  • Keep blood pressure stable with fluid infusion
  • Perform blood transfusion procedures, if there is  anemia  due to bleeding
  • Carry out dialysis procedures if you have kidney failure
  • Give fever and pain relievers, such as  paracetamol or ibuprofen
  • Give antibiotics or other treatment if yellow fever is accompanied by a bacterial infection

Yellow Fever Complications

The following are some of the complications that can arise from yellow fever:

  • Delirium
  • myocarditis
  • Jaundice ( jaundice )
  • Pulmonary oedema
  • Hepatorenal syndrome
  • Brain inflammation  (encephalitis)
  • Secondary bacterial infections, such as pneumonia and bloodstream infections
  • Internal bleeding
  • Kidney failure
  • heart failure
  • Coma
  • Dead

Prevention of Yellow Fever

Yellow fever is not an impossible condition to prevent. The following are some ways you can prevent yellow fever:


Vaccination is the most important way to prevent yellow fever. Some countries even require tourists to have an immunization certificate before entering the country.

Therefore, if you have plans to go abroad, consult with your doctor about vaccination at least 3-4 weeks before departure.

One dose of the yellow fever vaccine can provide lifelong protection. However, for someone who frequently travels to endemic areas, it is advisable to repeat the vaccine dose every 10 years.

The side effects of this vaccine are generally mild, namely headaches, low-grade fever, muscle aches, fatigue, and pain at the injection site.

The yellow fever vaccine is safe for anyone from 9 months to 60 years of age. However, there are several groups that need special attention before undergoing vaccination, namely:

  • Pregnant mother
  • Infants less than 9 months old
  • Someone who is over 60 years old
  • People who have previously been infected with yellow fever
  • Someone who is seriously allergic to egg protein
  • People with weak immune systems, such as people with HIV/AIDS

Consult further with your doctor if you belong to one of the groups of individuals above and plan to get yellow fever vaccination.

Protection from mosquito bites

In addition to vaccination, the risk of yellow fever can also be reduced by protecting yourself from mosquito bites through the following efforts:

  • Use long sleeves and long pants, especially if you are outdoors.
  • Install mosquito nets in air holes, such as at doors or windows.
  • Use mosquito nets, if you don't have air conditioning or mosquito net windows at home.
  • Use mosquito repellent lotion according to the instructions and don't overdo it, because mosquito repellent lotions can be toxic.
  • Use products that are meant for babies and children if you want to use  mosquito repellent lotions on babies and children.
  • Use some natural ingredients that are also able to provide protection against mosquito bites, such as eucalyptus oil.
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