Diagnostic challenges in COVID 19 and dengue co-infection: a case series report from tertiary care centers of Saudi Arabia

BACKGROUND: COVID-19 has changed the pattern of clinical diagnosis and laboratory confirmation for many communicable diseases making it essential for treatment procedures overburdening the health care system. Dengue and COVID-19, though caused by distinct viral pathogens, often present with overlapping clinical features, particularly in tropical and endemic regions. This overlap poses significant diagnostic challenges, especially during co-epidemics. OBJECTIVE: To analyze the clinical presentation of patients suspected of dengue and/or COVID-19, and to highlight key similarities and differences that may assist in timely diagnosis and management. METHODS: A retrospective case series of 50 patients admitted to multiple hospitals in a city in Saudi Arabia during a period of concurrent dengue and COVID-19 transmission was conducted. Patients were evaluated based on demographic characteristics, presenting symptoms, laboratory findings, and final diagnoses. RESULTS: The mean age of patients was 39 ± 11.8 years, with 86% male and 14% female participants. Clinical overlap was considerable-fever, headache, myalgia, and rash were commonly reported in both infections. Notably, a cutaneous rash, classically associated with dengue, was observed in 36% of patients, including some confirmed COVID-19 cases. Misdiagnoses occurred due to atypical presentations, including a case initially diagnosed as dengue based on a petechial rash, later confirmed to be COVID-19. Co-infection cases exhibited more severe symptomatology and prolonged recovery. Most patients recovered after supportive management. However, co-infected patients demonstrated extended hospitalization and increased disease severity compared with mono-infected cases. CONCLUSION: This case series underscores the diagnostic complexity posed by the clinical similarity between dengue and COVID-19, particularly in endemic settings. Accurate and early differentiation through combined clinical and laboratory approaches is crucial to avoid misdiagnosis, ensure appropriate treatment, and reduce morbidity.