Yellow fever

About

Yellow fever is an acute viral hemorrhagic disease caused by the yellow fever virus. It is spread by mosquitoes and can be found mainly in sub-Saharan Africa and tropical South America. Early symptoms of the disease include fever, chills, nausea, headaches, body aches and fatigue. If the infection progresses, it can cause serious complications such as jaundice, bleeding, multiple organ failure and in some cases, death. Vaccination is the primary prevention method for yellow fever, so it is important to get vaccinated before travelling to an area where the virus is present.

Symptoms

The symptoms of yellow fever include fever, chills, headache, muscle pain, back pain, and loss of appetite. Other symptoms may include nausea, vomiting, and yellowing of the skin and whites of the eyes (jaundice). Severe cases may also cause more serious symptoms such as bleeding, abdominal pain, liver failure, and kidney failure. In some cases, yellow fever can be fatal.

Causes

Yellow fever is an acute viral illness spread through the bite of an infected mosquito. The most common known causes of yellow fever are the presence of the yellow fever virus in wild primates, humans, and other animals, as well as contact with humans or animals who have been infected by the virus. Additionally, the Aedes aegypti mosquito is the primary vector for transmitting the virus from infected primates to humans. Finally, the virus can also be acquired through the consumption of contaminated food or water.

Risk factors

The primary risk factor for contracting yellow fever is physical contact with an infected mosquito. Mosquitoes can become infected when biting an individual already infected with the virus. Mosquitoes carrying the virus can also transmit it to other individuals that they bite.

Additional risk factors for yellow fever include living or traveling to an area where the virus is common, being in close proximity to an infected individual, or engaging in activities that involve contact with an infected individual or the environment (such as camping, hiking, or fishing). It is also possible to contract the virus through organ donation or blood transfusions.

Diagnosis

Yellow fever is typically diagnosed by a combination of the patient’s reported symptoms, physical exam results, and laboratory tests. A doctor may request a blood test to confirm the diagnosis, which looks for antibodies to the yellow fever virus. Additionally, a doctor may request a throat swab, sputum sample, or urine sample to check for the virus. Tests that measure the amount of virus in the blood or check for antigens released by the virus can also be used to diagnose yellow fever.

Sub-types

The World Health Organization (WHO) recognizes three distinct subtypes of yellow fever: jungle/sylvatic yellow fever, urban yellow fever, and intermediate yellow fever. Jungle/sylvatic yellow fever is spread in rural areas by mosquitoes and primarily affects non-human primates such as monkeys. Although humans can become infected, the disease is more often contracted from contact with an infected primate. Urban yellow fever is spread by an infected mosquito in more densely populated areas and primarily affects humans. This strain is more severe and can cause an epidemic in densely populated cities. Intermediate yellow fever is a hybrid of the other two subtypes and is caused by both mosquito contact and contact with an infected primate.

Treatments

The best way to prevent yellow fever is to be vaccinated. In areas where the disease is a risk, people should get vaccinated before traveling. In some cases, it is also recommended to get a booster dose of the vaccine every 10 years.

If someone is already infected with the yellow fever virus, there is no specific treatment. However, supportive care, such as fluids, can help relieve the symptoms and complications. In severe cases, hospitalization and intensive care may be necessary.

Prevention

The best way to reduce the risk of Yellow fever is to get vaccinated. A yellow fever vaccine is available through a health care provider and is recommended for travelers going to or living in parts of Africa and South America where yellow fever is found. Additionally, travelers to these areas should take steps to protect themselves from mosquito bites by wearing long-sleeved shirts, long pants, and using insect repellent. Staying in places with air conditioning and window and door screens can also help.

Gender differences?

Yes, there may be gender-specific differences in the presentation and management of Yellow fever. Women may experience more gastrointestinal symptoms such as nausea, vomiting, and diarrhea than men. In addition, women may experience more severe jaundice and myocarditis (inflammation of the heart muscle) than men.

Women may also have worse overall prognosis than men, with higher mortality rates and longer recovery times. Women may also be more likely to experience complications such as meningoencephalitis (inflammation of the brain and spinal cord). Lastly, women may require more frequent and aggressive treatment for Yellow fever than men.

Nutrition

Nutrition plays an important role in the management of Yellow fever. Ensuring that the patient has adequate nutrition helps boost the body’s immune system, which helps it fight off infection and helps to reduce the severity of disease symptoms. It is especially important for patients with a weakened immune system, such as those infected with Yellow fever, to receive adequate nutrition to help protect and improve their health. A diet with adequate proteins, vitamins, minerals and fluids is recommended to help support the body’s defenses and aid in the recovery process. In severe cases, patients may require parenteral nutrition (intravenous nutrition) to help support the recovery process.

Physical Activity

Physical activity is not a direct cause of yellow fever. However, physical activity can have a significant impact on the risk of becoming infected with yellow fever. People who are physically active are more likely to be exposed to mosquitoes, which are the primary transmitters of the yellow fever virus. Insect repellent and other preventive measures should be used when engaging in any physical activity outdoors in an area where yellow fever is endemic or epidemic.