Case Presentation: A 21-year-old male with no past medical history presented to the hospital in October 2020 with over a week of abdominal pain, fever, cough, and congestion. The patient noted that these symptoms had persisted despite taking Augmentin for presumed sinusitis. He had a negative COVID-19 test 4 days prior to admission and no vaccine was yet available. He denied drug use, recent travel, or any sick contacts. On presentation, he was tachycardic to 115 beats/min with mild right upper quadrant abdominal tenderness. His labs were notable for a hemoglobin of 11.6 g/dL, platelet count of 101 THO/uL, AST of 183 U/L, ALT of 224 U/L, alkaline phosphatase of 305 U/L, with no leukocytosis or lymphopenia. ESR and high sensitivity-CRP were both elevated. A chest x-ray demonstrated bibasilar opacities and a small, left-sided pleural effusion. CT abdomen and pelvis was pertinent for hepatosplenomegaly, diffuse intra-abdominal lymphadenopathy, and small volume ascites. Blood cultures, viral studies including EBV, CMV, HIV, and SARS-CoV-2, and a tick-borne pathogen panel were obtained. Patient was started on ceftriaxone and azithromycin. However, he remained febrile to 102°F for the first three nights of hospitalization.A repeat SARS-CoV-2 test on hospital day 2 returned negative. Blood cultures grew Salmonella on the fourth day of admission. During additional discussion with the patient, he reported several days of vomiting and diarrhea that started after eating from a food truck three weeks prior. The blood cultures eventually speciated to Salmonella Typhi with intermediate susceptibility to levofloxacin; the patient was started on cefpodoxime, and his symptoms improved.
Discussion: At first glance, it may seem simple to differentiate COVID-19 and typhoid fever based on the clinical presentations; however, this case highlighted the key similarities that complicate this task, as well as the important distinguishing factors of the two entities. Firstly, the patient with typhoid fever presented with fever, cough, and congestion, a constellation of symptoms that is also consistent with COVID-19. The lab results are also alike in the two diseases, as both can present with thrombocytopenia and elevated liver enzymes. Furthermore, this patient with typhoid fever demonstrated bilateral consolidations in a lower-lung distribution, a pattern that is often seen in COVID-19.On the other hand, the patient also exhibited findings that are not unique to typhoid fever but more atypical of COVID-19. Specifically, the hepatosplenomegaly and intra-abdominal lymphadenopathy seen on the abdominal CT in the case are less consistent with a diagnosis of COVID-19. In addition, while COVID-19 may present with diarrhea, the temporal delay that the patient experienced between his initial gastroenteritis and the cough and fever that led him to present to the hospital is characteristic of typhoid fever, in which the febrile illness occurs between 3 and 21 days after the initial exposure due to the pathogen’s incubation time.
Conclusions: Typhoid fever presents with an illness script that has significant overlap with that of COVID-19. Only 50-70% of Salmonella cases result in positive cultures which may lead to diagnostic error. Important differentiating factors that point towards typhoid fever as demonstrated by this case are the abdominal imaging results and the temporal dissociation between gastroenteritis and the febrile illness with pulmonary manifestations.