The patient of a 71-year-old woman was admitted to our hospital because of fever for 10 days and dyspnea for 5 days on November 17, 2020. She presented with fever and chills 10 days before admission, and the maximum body temperature was 40 C, accompanied by fatigue and dry cough without sputum. Chest CT at the local hospital showed pneumonia in the inferior lobe of the left lung and mediastinal lymph node enlargement (Figure 1). Routine blood examination showed that the white blood cell count was 10.2 x 109/L and the CRP level was 139 mg/L. She went to a local clinic and applied cephalosporin antibiotics, but the above symptoms did not improve. Nausea and vomiting occurred 7 days prior, accompanied by diarrhea and watery stools, without abdominal pain. Then, she was hospitalized in the local hospital. Using ceftriaxone and moxifloxacin intravenously for 7 days showed no improvement. Dyspnea occurred 5 days prior and was aggravated after the event. One day before admission, the patient's dyspnea was significantly aggravated, and re-examination of chest CT was significantly worse than before (Figure 1). The patient was treated with tracheal intubation and ventilator-assisted ventilation. She was sent immediately to Shengjing Hospital of China Midical University and was hospitalized in the Department of Pulmonary and Critiacl Care Medicine.
The patient suffered from coronary atherosclerotic cardiopathy for 3 years, and she took aspirin intermittently. She had no hypertension and diabetes. She had no hepatitis and tuberculosis. She resides in Liaoning Province, northern China. She is a retired employee, has no smoking and drinking habits, and has no drug or food allergy.
When the patient was admitted to our hospital (day 1), her vital signs were as follows: body temperature 36.5 C, pulse rate 80 beats/min, respiratory rate 27 beats/min, blood pressure 117/69 mmHg, and pulse oxygen saturation 96% with a fraction of inspired oxygen (FiO2) of 0.80. Conscious, no yellowing of skin and sclera, no paleness of eyelid conjunctiva. Breath sounds in both lungs were rough, and wet rales were heard on auscultation. There was no audible murmur on cardiac auscultation. Tenderness in the abdomen and hepatosplenomegaly were not detected. No edema of both lower limbs.
The laboratory dates after admission to our hospital were as follows: arterial blood gas analysis showed a pH of 7.513, PaO2 of 98.6 mmHg, PaCO2 of 28.2 mmHg, HCO3- of 22.5 mmol/L and oxygenation index of 123.2. The white blood cell count was 18.5 x 109/L, with an elevated neutrophil ratio of 90.3%. The concentration of C-reactive protein (CRP) was 253.7 mg/L. The concentrations of procalcitonin (PCT, normal < 0.05 ng/ml) and interleukin-6 (IL-6, normal <=5.4 pg/ml) were 2.91 ng/ml and 12.64 pg/ml, respectively. The D-dimer (normal 0-252 mug/L) was 2161 mug/L. Albumin level (normal 35-53 g/L) was 23.0 g/L. Alanine aminotransferase (ALT, normal 0-40 U/L) was 68 U/L, and aspartate aminotransferase (AST, normal 5-34 U/L) was 69 U/L. Bilirubin, creatinine, and electrolytes were within normal limits. The creatine kinase (CK, normal 29-200 U/L) was 75 U/L, and the creatine kinase isoenzyme (CK-MB, normal 0-24 U/L) was 17.4 U/L. The concentrations of B-type natriuretic peptide (BNP, normal 0-154.7 pg/mL) and cardiac troponin I (cTnI, normal 0-0.0116 U/L) were 300.8 pg/ml and 0.7743 mug/L, respectively. Mycoplasma pneumoniae IgM was positive, and IgG was negative. Chlamydia pneumoniae IgM was negative, and IgG was positive. The Epstein Barr virus DNA quantification was 8.15E + 03 copies/ml (normal < 1.0E + 03 copies/ml). Tests for cytomegalovirus, influenza A virus, influenza B virus, aenovirus and legionella bacteria were all negative. The beta-D-glucan test and galacto Mannan test were both negative. T-SPOT-T and Tuberculin test were negative. The indicators for autoimmune diseases (anti-extractable nuclear antigen antibody, anti-nuclear antibody and anti-neutrophilic cytoplasmic antibody) were negative. The numbers of CD3 (normal 690-2,540/mul), CD8 (normal 190-1,140/mul) and CD4 (normal 410-1,590/mul) T lymphocytes in blood were 254, 41, and 165/mul, respectively. The concentrations of carcinoembryonic antigen (CEA, normal 0-5 ng/ml), cytokeratin 19 fragment (CYFRA21-1, normal 0.1-3.3 ng/ml) and neuron-specific enolase (NSE, normal 0-16.3 ng/ml) were 2.37, 6.30, and 17.32 ng/ml, respectively.
After admission, the patient continued to be treated with ventilator-assisted ventilation. Empirical anti-infective treatments, including meropenem, levofloxacin, ganciclovir, and arbidol, were used initially. After the initial treatment, the patient's peak temperature decreased, but she still had fever. On the second day of admission (November 18), the patient underwent bronchoscopic alveolar lavage examination, and bronchoalveolar lavage fluid (BALF) was sent to Nanjing Difei Medical Laboratory Co., Ltd. for mNGS examination. The concentration of interleukin-6 (IL-6) in the BALF was 4,519.04 pg/ml (normal range 0-5.4 pg/ml). On the 4th day of admission (November 20), the result of mNGS of the BALF was reported, and 70 sequence reads corresponding to C. psittaci were identified and there was no sequence read corresponding to other pathogens. The patient had no history of direct contact with birds and poultry before the illness, but there were neighbors raising pigeons in the residential area, not except for indirect contact. According to the results of mNGS of BALF suggesting C. psittaci infection (Table 1), antibacterial agents were switched to tigecycline (100 mg intervenous drop infusion on day 4, then 50 mg q12 h intervenous drop infusion on days 4-25) combined with levofloxacin (0.5 g qd intervenous drop infusion, days 2-7), and meropenem was discontinued. The patient's blood sample was sent to Guangzhou Weiyuan Gene Technology Co., Ltd. for mNGS testing again, and the results of the blood samples still identified 38 sequence reads corresponding to C. psittaci (Table 1). She was diagnosed with C. psittaci pneumonia. Her body temperature returned to normal on the 6th day of admission (Figures 1-4), and her dyspnea gradually eased. On the 7th day of admission (November 23), the patient's sputum culture revealed Pseudomonas aeruginosa and Candida albicans. Considering the patient had a secondary infection. According to the results of drug sensitivity, the patient was administered piperacillin tazobactam (4.5 g q8 h intervenous drop infusion, days 8-25) while strengthening oral care. The patient had sinus bradycardia, and the electrocardiogram showed a prolonged QT interval, so levofloxacin was ceased. On the 10th day of admission (November 26), the patient's tracheal intubation was removed. Re-examination of chest CT showed that lung inflammation was significantly absorbed (Figure 1). On the 24th day of admission (December 10), blood mNGS was performed again and was negative for C. psittaci (Table 1). Tigecycline and piperacillin tazobactam were discontinued. Re-examination of the chest CT (December 12) showed that the inflammation was well absorbed, and only a few fiber cord shadows were left. On the 29th day of admission (December 15), the patient was discharged from the hospital, and her status was close to premorbid condition.
Other bacteria, including Propionibacterium acnes, Moraxella osloensis, Staphylococcus hominis, Staphylococcus warneri, and Malassezia globose, were also detected by mNGS in the patient's blood samples (Table 1). These bacteria are all skin microecological flora and not considered as pathogenic bacteria.