This is a double-blind randomized controlled trial assessing the efficacy of adjuvant corticosteroids in clinically diagnosed Pneumocystis jiroveci pneumonia in infants.

The study aims to determine whether the early administration of adjuvant corticosteroids in addition to high dose oral Co-trimoxazole reduces mortality amongst infants aged 2-6 months with vertically acquired HIV and clinically diagnosed Pneumocystis jiroveci pneumonia. Infants will be randomized to receive either a steroid regime of oral prednisolone at 2 mg/kg for 7 days, then 1 mg/kg for 7 days, then 0.5mg/kg for 7 days for a total of 21 days or placebo.

Inclusion Criteria:

• Consecutive infants with HIV and clinical features of Pneumocystis jiroveci pneumonia who require oxygen (oxygen saturations in air < 90%).
• Clinical diagnosis of Pneumocystis jiroveci pneumonia will be made by one of the study investigators. All infants must be HIV ELISA positive or exposed, have an oxygen requirement (saturations on air < 90%) and have severe respiratory distress and cough. They may also have a low grade fever, clear chest or diffuse signs on auscultation and features suggestive of Pneumocystis jiroveci infection on chest radiography.

Exclusion Criteria:

• Previous known allergy or hypersensitivity or other contraindication to corticosteroids or co-trimoxazole.
• Previous treatment for suspected Pneumocystis jiroveci pneumonia or a delay starting steroids for greater than 24 hours after starting high dose co-trimoxazole.
• Patients who are not exposed to HIV.
• Infants with known preexisting active pulmonary or cardiac disease.
• Patients who do not live within the Blantyre district and who are unable to attend follow up at QECH.
• Infants whose parents or guardians refuse consent.