대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Leptospirosis

Radiologic Findings

Clinical findings:
This patient had residency in rural area and worked in the rice field during the harvest period following water flooding. He complained of fever, cough, and myalgia.
Hemoptysis was occurred in a couple of days after acute onset of a febrile illness.

Laboratory findings included leukocytosis and showed mild thrombocytopenia.
Blood chemistry revealed decreased protein and albumin and increased aminotransferase (AST and ALT) indicating hepatic dysfunction in all four patients.
He showed a mild increase of BUN and creatinine, suggesting renal dysfunction.
Initial arterial blood gas study revealed hypoxemia and compensatory hyperventilation.

One or two days after admission he demonstrated respiratory distress with decreased oxygenation (PaO2/FiO2) less than 200, and rapidly progressing bilateral infiltrates on chest radiography.
All of these findings are compatible with acute respiratory distress syndrome.

Early antibiotic treatment with doxycyclin was given and this patient survived with fully supportive care and appropriate treatment. Follow-up chest radiograph 5 days later after treatment shows marked improvement of lung opacities.

Brief Review

Leptospirosis is a zoonotic diseases caused by Leptospira interrogans in rodent and wild animals.
Human disease is acquired by contact with urine or tissues of an infected animal or through contaminated water or soil. Systemic infection of leptospirosis shows variable clinical symptoms and signs from indolent and fatal manifestation with multi-organ failure.

Leptospirosis can be complicated by ARDS, which needs the treatment of underlying disease and adequate supportive care with artificial mechanical ventilation.
The main causes of the disease, we believe, are heavy rain and water flooding during the summer, which leads to wide propagation of Leptospira.
Leptospirosis can occur as two clinical manifestations:
a self-limiting anicteric systemic illness, which occurs in 85-90 % of the disease,
and a septicemic leptospirosis, 10-15 % of patients.

Systemic leptospirosis is characterized by abrupt onset of chills, fever, headache, and myalgia.
Anorexia, nausea, vomiting, and abdominal pain can occur occasionally.
Weil's disease, icteric leptospirosis, is the severest form of the disease and characterized by the presence of impaired renal and hepatic function, multi-organ internal hemorrhage, vascular collapse, and severe alteration in consciousness.

The radiologic findings of the lung are reported as three forms:
(1) multiple nodular opacities (air-space nodules) ranging from 1 to 7 mm in diameter with or without associated focal areas of consolidation (57%);
(2) large confluent areas of consolidation (16%); and
(3) diffuse, ill-defined areas of ground-glass opacity (27%).

In all patients, the abnormalities were bilateral and nonlobar in distribution; in approximately 50%, they involved mainly the peripheral lung regions. Other findings included small pleural effusions (19%) and cardiomegaly (27%).

References

1. Fraser and Pare's Diagnosis of diseases of the chest. 4th ed. 776-777.

2. Im JG, Yeon KM, Han MC, et al. Leptospirosis of the lung: radiographic findings in 58 patients. AJR 1989 152;955.

Keywords

Lung, Infection, Bacterial infection,