Letters to the Editor.

Abstract

Visceral leishmaniasis (VL) is a chronic parasitic infection caused by sandflies.1, 2 It is estimated that about 90 000 new cases of VL occur world-wide every year.1 The incidence of VL in Oman was 5–25 cases/year in the early 1990s but has dropped significantly with the spraying operations and other infection prevention and control measures to 0–1 cases between 2010 and 2015.3 There is limited data on VL in Omani children especially those who developed haemophagocytic lymphohistiocytosis (HLH).1 Elnour et al. reported 33 Omani children managed for VL between 1993 and 1999 who all had fever, iron deficiency anaemia and splenomegaly at the time of diagnosis. The majority were from Al-Sharqiyah region in east Oman. All these children were managed with sodium stibogluconate and all of them responded very well except two children who died from associated complications. None of these children had VL-associated-HLH.2 VL-associated HLH in children is extremely rare with less than a hundred cases reported in the literature and there is little reported from our area.1 After reporting the 3-year-old boy with VL-associated haemophagocytic lymphohistiocytosis (HLH) in the Journal of Paediatrics and Child Health,4 we looked retrospectively for the VL-associated HLH cases managed in Oman in the two main admitting centres in Muscat. These two centres manage all cases of HLH in the country. We identified two children managed for VL-associated HLH since 2007. In addition, we identified another two Omani children reported in the literature in the early 2000s.5, 6 Table 1 summarises all cases of VL-associated HLH in Oman in the last 20 years. All of these children were <4 years of age, with a median age of 12 months at the time of presentation. Four (4/5; 80%) were males and all were from the Al-Sharqiyah region. All were healthy children but one was diagnosed later with a degranulation defect (Munc 13-4) who was managed later at 5 years of age for Epstein–Barr virus-associated HLH. All reported children presented with fever and had hepatosplenomegaly on examination. Pancytopenia and hyperferritinaemia were the most common laboratory abnormalities. Only one patient had Leishmania donovani bodies (LD bodies) from the first bone marrow aspirate. Another three had repeat BMA testing as they did not improve with HLH chemotherapy, and VL was diagnosed on the second or third attempts. All received courses of HLH protocol initially, which ceased after confirming the diagnosis of VL. They were managed with amphotericin B with different dosing and durations and recovered well. No reported mortality. In conclusion, VL-associated HLH is uncommon in Oman and it was mainly observed from Al-Sharqiyah region. Bone marrow had low diagnostic sensitivity in our patients. Omani children presenting with HLH should be investigated for VL especially if they live in Al-Sharqiyah region.