P1.008: Severe Clinical Manifestations of Chikungunya and Dengue-Chikungunya Coinfection in Pediatric Patients Hospitalized in the Intensive Care Unit in Cali, Colombia

Introduction: Chikungunya virus (CHIKV) and Dengue virus (DENV) are major public health concerns in endemic regions like Colombia. While these infections often present with classical symptoms such as fever, rash, and arthralgia, severe and atypical manifestations can arise, particularly in coinfections. This report describes five pediatric cases with severe DENV-CHIKV coinfection requiring intensive care.

Case Description: Case 1: A 1-year-old male presented with fever, vomiting, and diarrhea. Within 24 hours, he developed hemodynamic instability requiring PICU admission. Neurological symptoms progressed to irritability, altered consciousness, and focal seizures. CSF analysis revealed viral meningitis. NS1 antigen and IgM for DENV were positive, while RT-PCR in serum and CSF confirmed CHIKV. The patient recovered after 15 days in PICU.

Case 2: A 9-year-old female developed systemic inflammatory response syndrome with hepatosplenomegaly, pleural effusion, and peritoneal ascites. Hemophagocytic lymphohistiocytosis was confirmed. Despite corticosteroids, cyclosporine, and IVIG, the patient died. RT-PCR confirmed CHIKV infection.

Case 3: A 15-year-old male presented with fever, myalgias, rash, and hepatosplenomegaly. Echocardiography revealed dilated cardiomyopathy and myocarditis, diagnosed as incomplete Kawasaki syndrome. The patient required IVIG treatment. NS1 antigen, IgM for DENV, and RT-PCR in serum confirmed DENV-CHIKV coinfection. He recovered fully.

Case 4: A 14-year-old male presented with fever, headache, arthralgia, and conjunctival hemorrhage. The patient experienced generalized seizures, and CSF analysis confirmed viral meningitis. NS1 antigen, IgM for DENV, and RT-PCR in serum and CSF confirmed DENV-CHIKV coinfection. The patient recovered without sequelae.

Case 5: A 6-year-old female presented with fever, headache, and abdominal pain. She developed shock, respiratory distress, and pleural effusion requiring non-invasive ventilation. CSF analysis suggested viral meningitis. NS1 antigen, IgM for DENV, and RT-PCR in serum and CSF confirmed DENV-CHIKV coinfection. The patient improved after 6 days in PICU without sequelae.

Discussion: These cases highlight the broad spectrum of severe manifestations in pediatric DENV-CHIKV coinfection, including neurological, cardiovascular, and hematological complications. Early diagnosis using RT-PCR and serology, coupled with intensive supportive care, is essential to improve outcomes.

Conclusion: Pediatric patients with CHIKV or DENV-CHIKV coinfection can present with severe and atypical clinical manifestations, including encephalitis, myocarditis, and hemophagocytic lymphohistiocytosis. Early diagnosis using molecular and serological tests, combined with intensive supportive care, is essential for improving outcomes. These cases highlight the need for heightened clinical suspicion in endemic regions.