Hand, foot, and mouth disease (HFMD) is most contagious during the first week of illness. However, the virus can still be spread to others for days or even weeks after symptoms have resolved. People can also be contagious before symptoms appear and even if they never show symptoms at all. Key points on contagiousness duration:
- Most contagious: First 7 days after symptoms start
- Virus shedding can continue from the respiratory tract for 1 to 3 weeks and in stool for several weeks to months after infection begins
- Maximum viral excretion can last up to 3 to 4 weeks from the respiratory tract and 6 to 12 weeks from feces
- Isolation or staying home is generally recommended for 7 to 10 days or until fever-free for at least 24 hours and vesicles have dried up to reduce spread
In summary, HFMD is highly contagious mainly during the first week of illness but can remain contagious for several weeks afterward due to prolonged viral shedding, especially in stool. Careful hygiene and isolation during this period help prevent transmission to others
