What Is Yellow Fever?
Yellow fever refers to jaundice that presents in a patient infected with the virus by getting a bite from a mosquito carrying the virus. The virus is arbovirus of the flavivirus genus. And the species of the mosquito is Aedes and Hemogogus.
The disease endemic in tropical areas of Africa, Central, and South America especially Brazil. Circulate in the highest concentrated population with a high density of mosquito. An area that yellow fever vaccination not previously recommended.
*According to WHO, between 1 July 2017 and 28 February 2018, 723 confirmed human cases of yellow fever had reported in Brazil, including 237 deaths. This number increase since 2015/2016.
What Are The Symptoms Of Yellow Fever?
Symptoms include fever, headache, jaundice, muscle pain with prominent back pain, loss of appetite, nausea, vomiting, and fatigue. Most cases are asymptomatic for few days after bitten by a mosquito. Some symptoms disappear after 3 to 4 days.
Severe symptoms or toxic phase just within 24 hours after initial symptoms disappear may occur. By high fever and affected several systems such as liver and kidney. The patient will develop jaundice, dark urine and abdominal pain with vomiting. Bleeding can occur from patient’s mouth, nose, ear or stomach. Within 7 – 10 days, half of the patient may die.
Misleadingly yellow fever symptoms can be confused with severe malaria, leptospirosis, viral hepatitis, other hemorrhagic diseases, and poisoning. But testing Polymerase chain reaction (PCR) in blood and urine can help detect the disease in early stage.
Do I Have Possibility Getting Yellow Fever?
High-risk people are people who live in an endemic area in Africa and Central South America. Travelers who visit the yellow fever area may spread the disease in another country. Old people over 60 years old or patients with severe immunodeficiency can easily get infected.
How Can Yellow Fever Transmit?
Three ways can transmit the disease. First, a worker who’s working in the jungle or brave traveler roaming in the forest is bitten by a mosquito. The mosquito transfer the virus in monkeys which is a reservoir host for the virus by biting them.
The second way is the mosquito infected both monkey and human. The mosquito roaming in the jungle and household. Increase contact from both of species will lead to outbreaks even in neighborhood village at the same time. In Africa, the second way is the most common way to cause an outbreak of yellow fever disease.
The third way is when infected people bring the disease in an area with high density of mosquito and lack of vaccination. Plus this people usually have low immunity and easily to be infected. In this case, the disease transmitted from people to people.
Do We Have Treatment For Yellow Fever?
Treatment is supportive treatment from the hospital. The specific drug for yellow fever is still under development. Treating the symptoms present such as liver or kidney failure and fever may improve the outcomes.
We can prevent it!
By highly effective vaccine which is safe and affordable. A single dose is sufficient to prevent the disease and prolong the lifespan. Plus a booster dose is not needed. Within 30 days the vaccine provided effective immunity for the person vaccinated.
Prevention by vaccination is the most important step in battling against this disease. At least 80% of the population in an endemic area should be vaccinated to prevent the outbreak. Don’t forget the traveler who is going to visit the endemic area need to confirm whether they are vaccinated or not. Many countries require the traveler to prove that they have been vaccinated for yellow fever before issue visa, especially in endemic countries.
Some people excluded from vaccination. Please pay attention to this to avoid other problems.
- Infants aged less than nine months. But if the infants live in the endemic area, they are required to be vaccinated.
- Pregnant woman except during outbreak of disease.
- People with severe allergies to egg protein.
- People with low immunity due to HIV/AIDs and thymus disorder
Other prevention is mosquito control. Eliminate potential breeding sites by applying larvicides to prevent breeding of mosquito larva. We can put the larvicides in water container or places where water is collected.
Doing surveillance on Aedes or Hemogogus species by knowing which area have a high density of them can prevent further outbreak. We can apply vector control as early as possible. We also can prevent it by minimizing exposure of ourselves to avoid mosquito bite.
The Eliminate Yellow fever Epidemics (EYE) Strategy launched in 2017. An initiative to prevent, detect and respond to suspected case and outbreaks. With an objective to protect, prevent and contain outbreak as soon as possible. Many strategies have implied such as promoting vaccination, increase surveillance on mosquito and expanding partnership with different countries. Hopefully by 2026 more than 1 billion people will be protected against the disease.