**Core Concept**
Hepatitis A virus (HAV) shedding in faeces is a critical aspect of its transmission dynamics. HAV is a highly infectious virus that can be spread through the fecal-oral route, where the virus is ingested through contaminated food, water, or direct contact with an infected person.

**Why the Correct Answer is Right**
HAV shedding typically begins 2-3 weeks before the onset of symptoms, with the highest viral loads in the feces during the incubation period. This period of shedding continues for approximately 1-2 weeks after the onset of symptoms, making it a significant risk factor for transmission. The virus is most contagious during this time, as the infected person may not even be aware they are shedding the virus. The high viral loads during this period make it challenging to control the spread of the virus.

**Why Each Wrong Option is Incorrect**
**Option A:** One week before the symptoms appear is incorrect because HAV shedding typically begins 2-3 weeks before the onset of symptoms, not just 1 week.

**Option B:** Two weeks after the symptoms appear is incorrect because while HAV shedding can occur after the onset of symptoms, the highest viral loads and contagiousness are typically observed during the incubation period, not after symptoms have appeared.

**Option C:** One week before the symptoms and one week thereafter is incorrect because it underestimates the duration of HAV shedding, which can occur for approximately 2 weeks before and after the onset of symptoms.

**Clinical Pearl / High-Yield Fact**
It's essential to note that HAV infection is self-limiting, and most individuals recover without treatment. However, it's crucial to take preventive measures, such as proper hand hygiene, to prevent the spread of the virus, especially among high-risk groups like healthcare workers and individuals with weakened immune systems.

**✓ Correct Answer: D. Two weeks before the symptoms and two week thereafter**