Cytomegalovirus-Associated Thrombocytopenia in an Immunocompetent Infant: A Case Report

Cytomegalovirus (CMV) is a β-herpesvirus. In immunocompromised individuals, CMV infection can cause life-threatening complications such as encephalitis, pneumonia, hepatitis and organ rejection. In contrast, immunocompetent children often present with mild infection, with thrombocytopenia being a common hematological complication.

A 2-month-18-day-old female infant was transferred to a tertiary hospital due to a 2-day fever and 1-day generalized petechiae. Physical examination revealed scattered skin petechiae without lymphadenopathy, hepatosplenomegaly or other systemic symptoms. Laboratory tests showed moderate thrombocytopenia with a platelet count of 35 × 10⁹/L, and platelet transfusion was not required, elevated liver transaminases, positive CMV IgM and IgG, and detectable peripheral CMV-DNA load, confirming acute CMV infection. The infant received only hepatoprotective treatment during an 8-day hospitalization, without intravenous immunoglobulin or antiviral agents.

The platelet count and liver function improved gradually during hospitalization. At two-week follow-up after discharge, blood cell parameters and liver enzymes returned to normal, and peripheral CMV-DNA declined to undetectable levels. Platelet counts remained stable in the subsequent 2-month follow-up.

CMV-associated thrombocytopenia in immunocompetent infants is usually self-limiting. Close dynamic monitoring of hematological and hepatic indicators is essential. Antiviral therapy should be prescribed cautiously, and individualized management is recommended for mild CMV infection in young infants.