{Reference Type}: Case Reports {Title}: Metagenomic Next-generation Sequencing May be a Tool for Timely Diagnosis of Seronegative and Primary Toxoplasma Infection After Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report and Literature Review. {Author}: Lv Q;Cao Y;Wang J;Meng L;Wang G; {Journal}: Pediatr Infect Dis J {Volume}: 43 {Issue}: 2 {Year}: 2024 Feb 1 {Factor}: 3.806 {DOI}: 10.1097/INF.0000000000004170 {Abstract}: We report a case of Toxoplasma gondii ( T. gondii ) antibody seronegativity in a 14-year-old boy with a primary infection of T. gondii after allogeneic hematopoietic stem cell transplantation for acute T-cell lymphoblastic leukemia who was rapidly diagnosed through metagenomic next-generation sequencing of peripheral blood as well as clinical manifestations. He was successfully cured with timely administration of trimethoprim-sulfamethoxazole due to early diagnosis.