老健施設における結核の外来性再感染と思われる集団発生について  [in Japanese] AN OUTBREAK OF PULMONARY TUBERCULOSIS PROBABLY DUE TO EXOGENOUS REINFECTION AT A NURSING HOME FOR THE ELDERLY  [in Japanese]

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Abstract

一度結核に感染あるいは発病した人が, 外来性再感染によって再度感染発病することは稀であると考えられている。私どもは, ある老健施設で感染源も含め27例の結核集団感染を経験した。感染源は, 同施設内の82歳の女性で, 空洞性病変が認められ, 喀痰検査ではGaffky8号, 培養陽性 (++++) であった。<BR>喀痰中の分離菌について, 感染源も含め19例でRFLP分析を行うことができたが, 18例は同一パターンで, 感染源からの集団感染であることが示された。これらの症例の中, 13例が私どもの病院に入院したが, 感染源を除く12例 (男3例, 女9例) は, 平均年齢が80.6歳 (67~89歳) で, 胸部X線では結核性病変を認め, 喀痰の塗抹, PCR, 培養検査などで<I>M.tuberculosis</I>が証明された。<BR>集団感染発生時 (1995年) のわが国における年齢80歳の結核既感染率は約80%と推定されるので, これらの症例の大部分は再感染による発病と考えられた。全例に老人性痴呆やその他の合併症等があり, 寝たきりで, 低栄養状態であった。また, 貧血, 低アルブミン血症, リンパ球の減少なども大部分の症例で認められた。これらの合併症による低栄養状態が, 再感染の一因であると思われた。

In Japan and other countries where tuberculosis is not so common, people who were once infected with tuberculosis are thought to rarely suffer from the disease again due to exogenous reinfection. We experienced a mass outbreak of tuberculosis with 27 patients (including the source of infection) at a nursing home for the elderly. Epidemiological investigation suggested that the source of infection was an 82-year-old woman resident. For about 2 years before this outbreak, she had complained of a productive cough. At the time of the diagnosis of tuberculosis, chest radiography revealed a cavitary lesion and a smear of her sputum revealed organisms rated as Gaffky No.8. Sputum culture was also positive (+ + + +).<BR>Of the 27 patients, 19 (including the source) underwent restriction fragment length polymorphism (RFLP) analysis of isolates from the sputum. Eighteen patients showed an identical RFLP pattern, indicating that the infection had arisen from one source. Out of all patients, the source case of infection, 9 others with the same RFLP pattern, and other 3 who did not undergo RFLP analysis were admitted to our hospital. In 12 patients (3 men and 9 women excluding the source case) aged 80.6 years (range: 67-89 years), chest radiography disclosed tuberculous lesions, and smears, the polymerase chain reaction, and culture of sputum demonstrated <I>Mycobacterium tuberculosis</I>.<BR>As the prevalence of tuberculosis infection in Japanese aged 80 years at the time of the mass outbreak (1995) was presumed to be about 80 %, the disease seemed to be caused by exogenous reinfection in most of these patients. All of the patients had senile dementia and other complications, and they were bedridden and undernourished. Anemia, hypoalbuminemia and lymphocytopenia were also observed in most of the cases. Malnutrition due to these complications appeared to be a possible risk factor of tuberculosis caused by exogenous reinfection.

Journal

  • Kekkaku(Tuberculosis)

    Kekkaku(Tuberculosis) 77(5), 401-408, 2002-05-15

    JAPANESE SOCIETY FOR TUBERCULOSIS

References:  25

Cited by:  10

Codes

  • NII Article ID (NAID)
    10008879548
  • NII NACSIS-CAT ID (NCID)
    AN00073442
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    00229776
  • NDL Article ID
    026779663
  • NDL Call No.
    Z19-133
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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