Prevalence of malaria, dengue, and typhoid fever among children presenting with acute undifferentiated febrile illness (AUFI) landing at the emergency department of the National Institute of Child Health, Karachi

Objective: To determine the prevalence of malaria, dengue and typhoid fever among children presenting with acute undifferentiated febrile illness. Method: The descriptive, cross-sectional study was conducted from September 2022 to February 2023 at the emergency department of the National Institute of Child Health, Karachi, and comprised children aged <14 years with fever of unknown cause over the preceding 3-15 days. Whole blood samples were used for malaria slides and malarial parasite immunochromatographic tests. The serum was subjected to dengue non-structural antigen 1, immunoglobulin M and immunoglobulin G rapid diagnostic tests. Typhoid was diagnosed via blood culture. Antimicrobial susceptibility testing was also performed. Data was analysed using SPSS 22. Results: There were 290 patients with mean age 6.08±3.32 years. Out of 290,156(54%) were male while 134(46%) were female. Typhoid fever was identified in 25(8.8%) cases, followed by malaria 11(3.8%) and dengue 4(1.2%). The majority of patients 260(86.2%) had no confirmed diagnosis for these infections. No co-infections were identified. 19 out of 25 (75%) Salmonella typhi isolates demonstrated resistance to quinolones and while 18 out of 25 (73%) were resistant to third-generation cephalosporins, while all the isolates 25(100%) were sensitive to macrolides and carbapenems. No statistically significant associations were observed between demographic variables and infection status (p>0.05). Conclusion: Typhoid fever was the most frequently identified infection among the three causes of acute undifferentiated febrile illness. However, most cases remained undiagnosed, indicating the need for broader diagnostic evaluation. Key Words: Acute undifferentiated febrile illness, Children, Dengue, Malaria, Typhoid, Antimicrobial resistance.