Most cases of toxoplasmosis are mild and don't require treatment. Either no symptoms develop, or a full recovery is made without complications.
You may need treatment if you're diagnosed with toxoplasmosis and:
Babies diagnosed with toxoplasmosis before or after they're born (congenital toxoplasmosis) will also need treatment.
Most people will be treated with a combination of medicines called pyrimethamine, sulfadiazine and folinic acid. These medications usually need to be taken for at least four to six weeks. Sometimes a medication called azithromycin is given alone instead.
Treating pregnant women
If you're pregnant and develop toxoplasmosis for the first time, you may be treated with an antibiotic called spiramycin until you give birth or tests show your baby is also infected.
It's thought spiramycin may reduce the chance of the infection spreading to your baby, although it's not clear exactly how effective it is. In some cases, the infection may spread to your baby despite treatment.
If tests show the infection has already spread to your baby, you'll normally be treated with courses of pyrimethamine plus sulfadiazine, alternating with courses of spiramycin.
Treating toxoplasmosis in babies
If your baby is born with congenital toxoplasmosis, he or she will be examined and have tests to see whether the infection has caused any damage.
Your baby will usually be treated with pyrimethamine and sulfadiazine because this may help reduce the risk of serious or long-term problems. These medications may need to be taken for up to a year.
Unfortunately, these medicines can't undo any damage that has already occurred, so some babies with congenital toxoplasmosis will develop long-term or recurrent problems despite treatment.
Read about the complications of toxoplasmosis for more information about this.
Treating people with a weak immune system
If you have a weak immune system – for example, because you have HIV or you are taking medication to weaken your immune system after an organ transplant – you may be given medications called trimethoprim and sulfamethoxazole to prevent the symptoms of toxoplasmosis developing.
This is because the toxoplasmosis parasite remains inactive in the body even if you were infected a long time ago. If your immune system weakens, the parasite can reactivate and cause serious problems.
It may be possible to stop taking these medicines if your immune system recovers.
If you have an active infection, you'll normally be given pyrimethamine and sulfadiazine treatment. These medicines may need to be taken for a few months or more.