diagnosis: legionella pneumonia(军团菌肺炎)
radiologic findings
plain chest radiograph taken at admission shows diffuse ground glass
opacities and reticular opacities in the bilateral lungs, which were not
present on chest film 5 months ago. chest ct shows ground glass
opacities in the bilateral lungs, particularly in the bll. the lesions mainly
occur in the posterior portion of the lung. he underwent urine legionella
antigen test, which revealed that the disease is legionella pneumonia.
after receiving antibacterial medication with levofloxacin, the symptom
improved and returned back to home.
brief review
the most common legionella species causing human disease is l. pneumophila.
this organism can cause both community-acquired pneumonia and nosocomial
pneumonia.
the prevalence of legionella pneumonia is 12.5%, the second most frequent
cause of pneumonia. besides, legionella pneumonia occurs more frequently in the
immunocompromised patients suffering from various diseases such as aids, kidney
transplant, and steroid therapy, dm, age older than 50 and so on.
although legionella pneumonia does not have specific radiologic features, the
most common findings are peripheral patchy consolidations, which usually spreads
rapidly. it usually involves more than one lobe and often the bilateral lungs as the
disease progresses.
on ct, according to kim et al’s study, legionella pneumonia can be manifested as
multiple pulmonary infiltrates such as lobar consolidation, lobular consolidation mixed
with ggos, and purely ggos involving the bilateral lungs. lobar consolidations were
fairly common in immunocompromised hosts. furthermore, cavities commonly occur
in patients with high-dose steroid therapy. whereas, multiple ggos without
consolidations are usually seen in immunocompetent patients.
to diagnose l. pneumophila infection, specific laboratory tests are needed; culture
with special selective media, direct florescent antibody test (dfa), serologic tests,
dna probe, and urinary antigen test. the drug of choice for this disease is
erythromycin. with appropriate therapy, complete recovery occurs in approximately
80% to 90% of cases, particularly if there is no underlying illness.
胸部平片显示双肺弥漫性分布的磨玻璃影和网状阴影。5个月前胸片没有如此表现。胸部ct表现双肺磨玻璃影,左下肺改变更显著。病变主要出现在肺后部。通过尿军团菌抗原检测,提示此疾病是军团菌肺炎。经过左旋氧氟沙星抗菌治疗,症状好转康复出院。
导致人类疾病最常见的军团菌的是嗜肺军团病菌,菌体能够导致群体和院内感染。军团菌肺炎占流行病的12.5%,位居第二位。除此之外,军团菌肺炎更经常发生在免疫力低下的各种疾病如艾滋病、肾移植、激素治疗、dm(糖尿病)、50岁以上老年人等。尽管军团菌肺炎没有特征性的放射学表现,最常见的表现为外带的斑片样实变,其蔓延迅速。病变进展往往累及多叶及双肺。
kim等人通过对ct研究,军团菌肺炎表现形式多样的肺部侵润,如肺叶实变、肺小叶实变合并磨玻璃影,双肺的单纯性磨玻璃影。大叶性实变通常见于免疫力低下的患者。此外,空洞一般发生在大剂量类固醇治疗的病人。对于嗜肺军团病菌感染,有效的实验室检查是必须的,如直接免疫荧光法,血清学检测,dna检查,尿抗原测试,首选药物是红霉素。通过恰当的治疗,如果患者没有潜在疾病,完全康复的几率占80%至90%。
[本贴已被 pp 于 2006-12-13 19:10:20 修改过] |