- If at day 29 assessment, tissue aspirate is positive but the patient is well, he/she will receive another complete course of treatment (but classified as treatment failure). The patient will be evaluated again on day 58. Those who still have a parasite positive tissue aspirate will be offered a rescue treatment. Those who are negative will be offered secondary prophylaxis if eligible (Pentamidine 4mg/kg IM once a month up to a maximum of 18 months).