How does yellow fever typically present after infection?

Yellow fever typically presents with an initial phase characterized by flu-like symptoms, including fever, chills, loss of appetite, and muscle pain. Following this initial phase, which lasts for about three to four days, some patients may improve, while others progress to a more severe phase. This severe phase often includes jaundice, which occurs due to liver damage from the virus, as well as abdominal pain, liver failure, and additional symptoms such as bleeding from the nose or gums.

The reason this presentation is particularly significant is due to the virus's ability to cause a marked deterioration in a subset of patients after they seem to recover from their initial symptoms. The appearance of jaundice signifies significant hepatic involvement and indicates a transition to a potentially life-threatening phase of the disease.

In contrast, the other options do not accurately capture the typical clinical progression associated with yellow fever. The description of being asymptomatic for the first two weeks, having a subtle onset, or experiencing immediate severe symptoms are not consistent with the common course and manifestation of the disease. Understanding this progression helps in recognizing and treating yellow fever effectively.