Unusually high frequency of dengue cases with warning signs in patients with no history of previous dengue infection at the Santa Rosa Hospital in Lima city

Introduction: In 2024, a dengue epidemic affected the city of Lima, a city of more than 10 million inhabitants, for the first time. The Santa Rosa hospital treated more than 5000 febrile patients between January and July 2024, identifying 1788 patients with dengue, 18.6% of them with warning signs or serious, despite being the first infection for them. In order to know the factors related to this unusually high frequency of cases with warning signs and severity in a group of patients who were infected for the first time, this study was developed. Methodology: The epidemiological records were reviewed and contrasted with the information from the hospital's emergency care records. The laboratory results were obtained from the laboratories of the hospital and reference in Lima. Results: Between January and July 2024, 5,862 febrile patients presented to the hospital emergency room, 1788 were considered cases of dengue. Nine cases (0.5%) were classified as severe dengue and 324 (18.1%) as dengue with warning signs. 4 died. 9.3% of patients over 65 years of age presented some warning or severity sign, while 6.4% of patients under 65 years of age presented warning signs (P 0.05). Only 2.5% (45/1788) responded that they had previously had dengue, but there was no difference between those who presented warning signs or severity. Conclusions: In conclusion, the dengue epidemic in Lima reached a greater severity than expected despite being the first infection for the affected population, a new massive outbreak and the entry of a new serotype could further increase the severity of the cases.