Yellow Fever – Symptoms, Diagnosis and Treatment
Yellow fever is a mosquito-borne viral illness found in parts of Africa and South America. It is not found in Singapore, but travellers venturing into affected countries risk infection. It could range from a relatively mild illness to a life-threatening condition affecting multiple organs. Understanding the symptoms, diagnosis, and treatment for can help a person with adequate knowledge to identify warning signs, so as to get timely medical assistance when necessary.
What is Yellow Fever?
Yellow fever is caused by the Yellow Fever Virus, which is transmitted to humans by the bite of an infected mosquito. It occurs primarily in tropical and subtropical regions of Africa and South America. While the majority will recover without severe complications, a minority may have liver, kidney, heart or multiple organ involvement and suffer from serious illness.
How Yellow Fever Develops
The Yellow Fever Virus is present in humans following a bite from an infected mosquito. After this, the virus multiplies in the body. Symptoms typically appear 3-6 days after exposure. The virus will spread throughout the body. During the early phase, it triggers an immune response. Following this, some individuals recover after this stage. A few will then progress into the severe phase, which involves organ damage.Research has shown that the disease can progress rapidly in certain patients, making early recognition and medical assessment important (Monath, 2001).
Common Symptoms of Yellow Fever
The early stages of Yellow Fever include non-specific signs like fever, headache, muscle ache, backache, chills, tiredness, nausea, vomiting and loss of appetite. Such signs mimic other common viral illnesses; therefore, they could not be immediately classified as Yellow Fever in many circumstances. A percentage of the people with illness will feel better after a couple of days, but a few will develop a severe course of illness (Chen & Wilson, 2020).
Serious Signs and Complications
There is the risk of people falling ill and having a serious Yellow Fever infection. They may develop symptoms such as jaundice, pain in the stomach, nose, or gum bleed, vomiting blood, kidney failure, trouble breathing or abnormality of the heart beats, shock and multiple organ failure.Such a disease carries a high mortality rate (Barnett, 2007)
How is Yellow Fever Diagnosed
To diagnose Yellow Fever, a doctor will obtain information on the symptoms, history of travel, vaccination and potential exposure to mosquitoes. Blood tests may be carried out to detect the presence of the virus, antibodies, liver function tests, kidney function tests and general health tests may be required. Diagnosis is often difficult as these signs are non-specific and are found in other infectious diseases in these regions, thus epidemiological surveys support testing to identify infected persons and locations of prevalence (Johansson et al., 2014).
How Yellow Fever is Treated
There is no specific medicine to treat Yellow Fever infection; treatment consists of supportive care, where rest is given, patients are encouraged to stay well-hydrated and given appropriate observation during treatment. People with more severe disease may be given oxygen and intensive care, such as hydration with fluids, oxygen supplement, liver and kidney support, and cardiovascular monitoring during treatment. Organ functions are continuously checked to ensure the organs are not being stressed beyond their limits, and further tests, such as blood tests, are carried out routinely (Staples et al., 2010).
Overview of Treatment for Yellow Fever
| Approach | Treatment Aim |
| Rest | Supporting the patient to recover from the infection. |
| Hydration | To ensure that the body maintains an adequate level of fluids. |
| Symptomatic relief | To address fever and other discomforts. |
| Blood test | To check on the progress of the infection. |
| Hospitalisation | For people with severe disease who require constant medical support. |
| Organ monitoring | Assessing the functionality and stress on the liver, kidney and heart. |
Advice for Travellers
Health care providers can provide travellers with information about relevant diseases in destination countries and give necessary recommendations on how to minimise potential illness risk during the journey. For example, the appropriate travel advice may also be concerned with the prevention of mosquito bites. They can recommend relevant preventive measures or prescribe appropriate medication for travelling and ensure all traveller vaccinations are up to date and necessary before the travellers leave. Travel health advice could equip individuals to be prepared for the potential risks during travelling and to remain in good health.
Vaccination for Yellow Fever
This method is currently the most effective way of treating the infection. Everyone travelling to regions with the presence of the Yellow Fever disease should get vaccinated before travellingto ensure their effectiveness. Vaccination may not only prevent the infection from the travelling destination, but it may also help to prevent disease outbreaks at the travellers’ destination and their country of origin. Individuals may require a medical check-up by healthcare providers to determine if vaccination is suitable for them and its timing as part of the pre-travel preparations.
About the Yellow Fever Vaccination Certificate
Travellers returning from certain countries with a risk of Yellow Fever transmission might be required to produce theirYellow Fever Vaccination Certificate for entry in Singapore. The Certificate of Vaccination serves as a medical record to allow travellers in without having to worry about the introduction of disease into Singapore. It is therefore important that all travellers take necessary measures to acquire the certificate before their travel.
Key Points to Remember
* Yellow fever is a viral infection spread by infected mosquitoes.
* Symptoms normally appear three to six days following a bite from the mosquito.
* Main symptoms include fever, headache, aching muscles, general fatigue, nausea, vomiting and lack of appetite.
* Complications of yellow fever can lead to bleeding and multiple organ failure.
* There is no cure for Yellow Fever, and it is treated by supportive therapy alone.
* Vaccination can only protect against Yellow Fever.
* In case of travellers planning an overseas trip and requiring advice, they should consult a travel health provider.
* All travellers to Singapore need to show a valid Yellow Fever Vaccination Certificate if required.
Consult CHI Health for Yellow Fever Vaccination and Travel Health Advice
Yellow fever remains a significant global public health issue, primarily associated with international travel. Early identification of symptoms, accurate diagnosis and proper medical management of Yellow Fever will decrease morbidity and reduce complications. Vaccination and prevention from mosquito bites and general health care before and during travel remain key aspects of disease prevention. If you are travelling abroad, Complete Healthcare International (CHI), the international medical clinic in Orchard, is happy to assist you in getting appropriate care, or if you want to know about the Yellow Fever vaccination, we are happy to help.