A 7-year-old male child, with a known case of nephrotic syndrome under treatment, presented to paediatrics emergency in September 2019 with features of shock with abdominal swelling. The child also had a history of fever, multiple episodes of loose watery stools and vomiting (three-four episodes per day), along with dull abdominal pain prior to shock. He was admitted in paediatric intensive care unit and managed with antibiotics and inotropes.
Spontaneous bacterial peritonitis with sepsis was the diagnosis, although the aerobic culture of peritoneal fluid was negative. Blood and urine cultures were also sterile.
The child had nephrotic syndrome since the age of 1.5 years and was on prednisolone and steroid-resistant since December 2015. A renal biopsy was performed in January 2016 and reported minimal change disease.
The patient was then started on tacrolimus 1 mg twice daily orally. The first relapse after taking tacrolimus was reported in April 2017 followed by two more relapses in 2017. The dose of tacrolimus was increased to 1.2 mg in July 2017. After that, multiple episodes of relapse were seen. Up to January 2019 the patient was on 10 mg prednisolone once daily orally along with tacrolimus. In February 2019, the dose of tacrolimus was increased to 2 mg twice daily along with prednisolone 30 mg per day (1.5 mg kg-1).
During the course of treatment the child had developed steroid-induced posterior subcapsular cataract and grade II hypertension. For hypertension he was on antihypertensive medication. He also suffered from pulmonary tuberculosis in 2018, for which he completed treatment. Further, there was a history of failure to gain weight and height proportionate to age. On general examination, oedema was observed with rashes on the face and left knee.
A stool sample was received in the microbiology laboratory and direct microscopy using 0.9 % saline and 1 % Lugol's iodine wet mount preparations revealed trophozoites and cysts of Giardia intestinalis, shown in Fig. 1. Modified Ziehl-Neelsen staining was performed for the identification of coccidian parasites and microsporidia and was negative. Chromotrope staining was also performed to see microsporidia and was also negative. However, on chromotrope staining, lightly stained cysts and trophozoites of G. intestinalis were seen, as shown in Fig. 2. Stool culture was negative for enteric pathogen.
Metronidazole 100 mg three times daily orally was prescribed for 10 days. After completion of the therapy with metronidazole for 10 days, cysts and trophozoites of G. intestinalis were still detected in stool samples on multiple occasions (four occasions up to the first week of February 2020), along with persistence of clinical symptoms intermittently. The child was on and off metronidazole therapy for 4 months at the same dose. In the first week of February nitazoxanide 200 mg (twice daily orally) was added to the therapy for 7 days. The last stool sample received on last week of February 2020 was negative for Giardia cysts and trophozoite. The child also had a past history of passing loose stool on and off with increased frequency and bloating since for the previous 1.5 years, but no significant findings had been reported in stool samples previously.