Pyogenic liver abscess / Recurrent liver abscess; Flu-like symptoms; This literature case was received on 22-May-2023, reported by other healthcare professional and concerned a 73-year-old, male patient.   This case report described a case of spontaneous liver abscess in a non-toxic patient that recurred ten years after a previous abscess. Liver abscesses are caused by direct spread from peritonitis, biliary tract infection or via hematogenous seeding from a distant source. Most are polymicrobial, however Escherichia coli and Klebsiella pneumoniae are the most common offending pathogens. Patients usually present with pain, fever, and clinical signs of infection.   The patient's concurrent condition included type 2 diabetes mellitus, hypertension, coronary artery disease (CAD) and abdominal aortic aneurysm. The patient's medical history included history of coronary artery bypass (CABG), percutaneous coronary intervention (PCI) three years ago, endovascular aneurysm repair and liver abscess growing Escherichia coli before ten years. The patient's concomitant medications were not reported.   On an unspecified date, the patient was vaccinated with influenza vaccine (brand not specified; dose, route of administration, anatomical location and indication: not reported). The batch number was not reported.  On an unspecified date, the patient was vaccinated with non-company, co-suspect COVID-19 booster vaccine (brand not specified; dose, route of administration, anatomical location and indication: not reported). The batch number was not reported.  On an unspecified date, an unknown amount of time after receiving influenza vaccine and COVID-19 vaccine, the patient had two weeks of dark urine. The patient developed flu-like symptoms with a self-resolving fever of 101.8°F. The patient had dark amber urine without dysuria or haematuria. Later, the patient experienced generalized weakness and decreased oral intake. Outpatient labs showed elevated liver function tests, and the patient was told to present to the emergency department (ED). On arrival, the patient was afebrile with stable vitals. Physical exam was unremarkable. Laboratory evaluation showed a haemoglobin of 11.7 g/dL, sodium of 133 mEq/L, creatinine of 1.4 mg/dL, aspartate aminotransferase of 117 U/L, alanine aminotransferase of 212 U/L, alkaline phosphatase of 825 U/L, total bilirubin of 4.1 mg/dL, and direct bilirubin of 2.1 mg/dL. Triple-phase computerised tomogram (CT) showed a 2.8 cm mass in the right liver lobe with linear enhancement. Ultrasound showed mixed echogenicity measuring 3.6x3x2.9x3 3.3 cm in segment 8 of the liver. On further evaluation, the patient had an Escherichia coli abscess diagnosed ten years prior, managed with antibiotics and drainage. At that time, the abscess was within the right inferior liver lobe, similar to his current abscess. Liver function tests (LFTs) down trended. Abscess was aspirated, with culture growing oxidase negative, gram-negative rods, likely Escherichia coli. The patient started on Ceftriaxone (ceftriaxone sodium) and metronidazole, to undergo colonoscopy as an outpatient and rule out colonic bacterial translocation.  The outcome of all events was not reported.  The reporter did not provide causality assessment.  In conclusion, pyogenic liver abscess can result in significant morbidity and mortality because of worsening infection and sepsis. Abscesses occur because of spread from adjacent infection or after recent surgeries.  The event of 'pyogenic liver abscess' was considered to be medically significant by a Physician within Seqirus's Pharmacovigilance and Risk Management Department.    Company comment: A 73-year-old patient developed two weeks of dark urine an unknown amount of time after receiving the suspect product influenza vaccine and COVID-19 vaccine. The patient developed flu-like symptoms with a self-resolving fever of 101.8°F. The patient had dark amber urine without dysuria or haematuria. Later, the patient experienced generalized weakness and decreased oral intake. Outpatient labs showed elevated liver function tests, and the patient was told to present to the emergency department. On arrival, the patient was afebrile with stable vitals. Physical exam was unremarkable. Laboratory evaluation showed a haemoglobin of 11.7 g/dL, sodium of 133 mEq/L, creatinine of 1.4 mg/dL, aspartate aminotransferase of 117 U/L, alanine aminotransferase of 212 U/L, alkaline phosphatase of 825 U/L, total bilirubin of 4.1 mg/dL, and direct bilirubin of 2.1 mg/dL. Triple-phase computerised tomogram showed a 2.8 cm mass in the right liver lobe with linear enhancement. Ultrasound showed mixed echogenicity measuring 3.6x3x2.9x3 3.3 cm in segment 8 of the liver. On further evaluation, the patient had an Escherichia coli abscess diagnosed ten years prior, managed with antibiotics and drainage. At that time, the abscess was within the right inferior liver lobe, similar to his current abscess. Liver function tests down trended. Abscess was aspirated, with culture growing oxidase negative, gram-negative rods, likely Escherichia coli. The patient underwent colonoscopy as an outpatient and rule out colonic bacterial translocation. Due to lack of information and unclear temporal relationship, causality for the event influenza like illness is unassessable. Based on biological implausibility, causal role of the suspect vaccine for the event liver abscess is assessed as not related.; Sender's Comments: A 73-year-old patient developed two weeks of dark urine an unknown amount of time after receiving the suspect product influenza vaccine and COVID-19 vaccine. The patient developed flu-like symptoms with a self-resolving fever of 101.8°F. The patient had dark amber urine without dysuria or haematuria. Later, the patient experienced generalized weakness and decreased oral intake. Outpatient labs showed elevated liver function tests, and the patient was told to present to the emergency department. On arrival, the patient was afebrile with stable vitals. Physical exam was unremarkable. Laboratory evaluation showed a haemoglobin of 11.7 g/dL, sodium of 133 mEq/L, creatinine of 1.4 mg/dL, aspartate aminotransferase of 117 U/L, alanine aminotransferase of 212 U/L, alkaline phosphatase of 825 U/L, total bilirubin of 4.1 mg/dL, and direct bilirubin of 2.1 mg/dL. Triple-phase computerised tomogram showed a 2.8 cm mass in the right liver lobe with linear enhancement. Ultrasound showed mixed echogenicity measuring 3.6x3x2.9x3 3.3 cm in segment 8 of the liver. On further evaluation, the patient had an Escherichia coli abscess diagnosed ten years prior, managed with antibiotics and drainage. At that time, the abscess was within the right inferior liver lobe, similar to his current abscess. Liver function tests down trended. Abscess was aspirated, with culture growing oxidase negative, gram-negative rods, likely Escherichia coli. The patient underwent colonoscopy as an outpatient and rule out colonic bacterial translocation. Due to lack of information and unclear temporal relationship, causality for the event influenza like illness is unassessable. Based on biological implausibility, causal role of the suspect vaccine for the event liver abscess is assessed as not related.