Can a positive 20-day laboratory test for Mycoplasma pneumoniae antibody in children turn negative?

There are generally two types of mycoplasma antibodies, one is IgM and the other is IgG. I don't know which one you're talking about. IgM is an antibody that begins to be produced 2-3 days after infection, begins to decline in 2 weeks, and disappears in 4-6 weeks, is not a protective antibody, and is used as an indicator of infection in diagnosis;

IgG generally begins to appear a week after infection with mycoplasma, and the two reach a peak, which can last for a long time, are protective antibodies, can neutralize pathogens, have the effect of clearing infection, and are beneficial and harmless to the human body.

So you don't need to think about this, if you don't have symptoms, a negative culture of secretions is cured.IgG is also harmless to the body if it persists. There are generally two types of mycoplasma antibodies, one is IgM and the other is IgG.

I don't know which one you're talking about. IgM is an antibody that begins to be produced 2-3 days after infection, begins to decline in 2 weeks, and disappears in 4-6 weeks, is not a protective antibody, and is used as an indicator of infection in diagnosis;

IgG generally begins to appear a week after infection with mycoplasma, and the two reach a peak, which can last for a long time, are protective antibodies, can neutralize pathogens, have the effect of clearing infection, and are beneficial and harmless to the human body.

So you don't need to think about this, if you don't have symptoms, a negative culture of secretions is cured. IgG is also harmless to the body if it persists.