Table 4

Assessment of medication toxicity, response to therapy and disease progression in infants treated for congenital toxoplasmosis

Toxicity
  • Full blood count to be done at baseline then during treatment to look for drug-induced neutropenia, aplastic anaemia and haemolysis (if co-existing G6PD deficiency).

    • Suggested timing is once weekly when on daily pyrimethamine then monthly if stable.

    • Withhold treatment if absolute neutrophil count <0.5 x109/L, but continue folinic acid (±consider increasing dose up to 20 mg).

  • Liver function tests and renal profile to be done at baseline then monthly if stable.

Response to therapy
  • Interval serology testing: T. gondii-specific IgG and IgM every 3 months until therapy is completed then at the end of treatment and at 1, 3 and 6 months off treatment.

  • Rebound rise in T. gondii-specific IgM±IgG levels may be seen following treatment; this does not necessarily indicate relapse but more likely reflects a delayed serological response to infection.

Disease progression and recurrence
  • Follow-up with paediatric infectious disease specialist team.

  • Measurement of head circumference at each outpatient visit.

  • Regular ophthalmology and vision assessments throughout treatment and at 3, 6 and 12 months following completion, then at least annually for life (to identify potential late-onset complications).

  • Consider neurodevelopmental, neurological and auditory review.

  • Inform parents about the risks of development of seizures and/or raised intracranial pressure: ensure they have an emergency action plan.

  • Urgently repeat brain imaging if there are any signs/symptoms of raised intracranial pressure.

  • Suggested time points only.

  • Ig, immunoglobulin; T.gondii, Toxoplasma gondii.