The key difference between yellow fever and jaundice is that although yellow fever is a disease, jaundice is a disease symptom which can be due to many other pathological conditions.
Yellow fever is a fatal infectious disease that is common in the African and South American continents. The causative agent of this disease is a virus belonging to the flavivirus group. Jaundice, on the other hand, is the yellowish discoloration of the mucosal layers of the body.
What is Yellow Fever?
Yellow fever, caused by a flavivirus, is a disease of widely varying severity. However, this disease is only prevalent in the African and South American continents. Aedes africanus in Africa and haemogonus species in South America transmit this disease.
Yellow fever has an incubation period of 3-6 days. Typically, there are three stages of disease progression. Clinical manifestations begin with a high fever, which resolves within 4-5days. There can also be associated retrobulbar pain, myalgia, flushed face, arthralgia and epigastric discomfort. Then, from the second day onwards, there is relative bradycardia. There is an intervening phase known as the phase of calm where the patient feels well and makes an apparent recovery. After this phase, the patient develops a high fever, hepatomegaly, jaundice, and bleeding from the gums. Ultimately, the patient usually goes into a coma few hours before death.
- Yellow fever is diagnosed clinically by the history of vaccination status of the patient and recent traveling to endemic regions.
- The virus can also be isolated from blood within 3 days from the onset of symptoms to confirm the diagnosis.
- There is no definitive treatment. Furthermore, supportive treatment includes maintenance of the fluid and electrolyte balance with bed rest.
What is Jaundice?
Jaundice is the yellowish discoloration of the mucosal layers of the body. This discoloration is due to the accumulation of bilirubin. During the hemolysis of red blood cells, haemoglobin brakes down into haem and globin components. The haem then converts into biliverdin by the action of haem oxygenase, which again converts into unconjugated bilirubin. Due to the low water solubility of unconjugated bilirubin, it is transported into the liver via blood by binding to albumin. After entering the liver, unconjugated bilirubin converts into conjugated bilirubin by attaching a water-soluble molecule to it. After that, bilirubin is released into the gut where the normal flora acts on it to produce stercobilinogen, which later becomes stercobilin. Also, some part of it excrets via the kidney as urobilin.
In a healthy neonate, jaundice can appear because of increased hemolysis and the immaturity of the liver to rapidly metabolize the bilirubin produced during the process. It is the physiological jaundice. Physiological jaundice usually appears 2-3 days after birth and gradually reaches the peak by one week. It can prevail for about 14 days before spontaneously disappearing. There is no need of doing further investigations. However, occasional phototherapy helps to accelerate the breakdown of bilirubin
Pathological jaundice can occur in any person and is a result of an ongoing pathological process that interrupts the normal bilirubin metabolism. Depending on the underlying cause, the pathological jaundice is further categorized into three groups as prehepatic, hepatic and post-hepatic jaundice.
- Hemolytic anemias and other red cell diseases
- Obstruction of the hepatobiliary system
- Damages to the hepatic parenchyma as in cirrhosis
- Infections such as hepatitis B
- Adverse effects of drugs
Biochemical studies to measure the levels of total bilirubin, indirect and direct bilirubin help to diagnose jaundice. Clinicians may go for other appropriate investigations depending on the suspected underlying cause
Management varies according to the underlying pathology that gives rise to jaundice. Jaundice will disappear spontaneously once you treat the cause aptly and eliminate it.
What is the Difference Between Yellow Fever and Jaundice?
Yellow fever is an infectious disease caused by flavivirus whereas jaundice is a disease symptom characterized by the yellowish discoloration of the skin and mucous membranes due to an abnormality in the bilirubin excretion. Most importantly, Yellow fever is an infectious disease whereas jaundice is a disease symptom. This is the key difference between yellow fever and jaundice.
Moreover, Flavivirus is the causative agent of yellow fever. In contrast, the cause of jaundice depends on its type; for example, hemolytic anemias and other red cell diseases and hemoglobinopathies cause prehepatic jaundice while obstruction of the hepatobiliary system and damages to the hepatic parenchyma cause posthepatic jaundice. Furthermore, the cause of hepatic jaundice is infections such as hepatitis B and adverse effects of drugs.
There is no definitive treatment for yellow fever. Moreover, supportive treatment includes maintenance of the fluid and electrolyte balance with bed rest. However, management of jaundice varies according to the underlying pathology that gives rise to jaundice. Once the cause has been aptly treated and eliminated jaundice will disappear spontaneously.
The major difference between yellow fever and jaundice is that yellow fever is an illness but jaundice is a symptom of different disease conditions including yellow fever.
1. Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009.
1. “This diagram illustrates the methods by which the arbovirus, yellow fever is transmitted to humans and non-human primate hosts by Aedes spp.” by CDC: Public Health Image Library (Public Domain) via Public Domain Files
2.”Cholangitis Jaundice” By Bobjgalindo – Own work (CC BY-SA 4.0) via Commons Wikimedia