Toxoplasmosis-Associated Secondary Hemophagocytic Syndrome: A Case Report and Literature Review

Background: Toxoplasmosis is an extremely rare disease that occurs in the hosts contact with cat and dog frequently. Most human acute infections go unnoticed in immunocompetent individuals, and gradually transformed into chronic infection. However, while host immunity significantly waned, the risk of reactivation of chronic toxoplasma infection is greatly increased. Reactivation of latent toxoplasmic infection often presents with fever, leukopenia, thrombocytopenia, neurological signs and pneumonia. However, for the non-specific clinical and biological signs and its fetal outcome, toxoplasmosis is often misdiagnosed and only revealed at autopsy. Case Presenation: We report a case hospitalized for a week history of cough, anorexia and fatigue with nasal bleeding for a day. After hospitalization, broad-spectrum antibiotherapy was started without a clear diagnosis of infection. Then the patient did a lot of investigations to search the cause of infection, but there were no positive findings. However, an unexpected discovery was detected from peripheral blood smears, shows 1 - 3 μm in diameter, scattered, short and bow like microorganisms on Day 39 of hospitalization. Combined with the medical history and clinical manifestation, toxoplasmosis was diagnosed finally. Unfortunately, secondary hemophagocytic syndrome (HPS) was diagnosed only two days after targeted anti-infection therapy, and the patient died on Day 45 of hospitalization. Conclusions: Patient with unexplained long-term fever and neurological symptoms, interstitial pneumonitis or myocarditis, toxoplasmosis should be positively considered. Only early diagnosis and treatment can increase the possibility of a successful cure and avoid other secondary diseases.