Published Date: 2005-02-07 23:50:00
Subject: PRO/EDR> Tuberculosis, supermarket exposure - Netherlands (Zeist)
Archive Number: 20050207.0411
TUBERCULOSIS, SUPERMARKET EXPOSURE - NETHERLANDS (ZEIST)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Mon 31 Jan 2005
From: Mick Mulders <email@example.com>
Source: Expatica.com [edited]
TB case prompts biggest Dutch health investigation
The largest tuberculosis (TB) investigation in Dutch history begins in
Zeist on Mon 31 Jan 2005. 5 percent of the 15 000 people undergoing tests
are expected to have been infected with the bacteria.
An employee of a C1000 supermarket in the central Dutch city was diagnosed
with a very infectious form of TB in November 2004. Initial tests confirmed
that the 25-year-old man's entire family and 40 of his 79 colleagues have
also been infected. Zeist City Council and the health authority GGD
Midden-Nederland decided to examine every customer who shopped at the
supermarket between 18 Nov 2004 and 1 Jan 2005 based on a telephone survey.
The GGD expects to test 15 000 people from the municipality this week [1st
week of February 2005].
75 percent of the C1000 customers urged to report for an examination will
undergo Mantoux tests. The procedure involves testing exposure to TB by
injecting diluted tuberculin under the skin. For people older than 60, lung
x- rays will be taken in a mobile health clinic.
TB doctor and the coordinator of the KNCV Tuberculosis Fund, Vincent
Kuyvenhoven, told newspaper De Volkskrant that it is reasonable to expect 5
percent of the people examined will be infected with TB. "But it could also
be 10 percent," he said.
Kuyvenhoven -- who said the investigation was the largest of its kind in
the Netherlands -- explained that the infection rate is dependent on many
factors. This includes how closely the infected supermarket employee came
into contact with customers.
Mick N. Mulders
[It is not stated in the posting whether the index case had laryngeal
tuberculosis or not. It has been generally accepted that laryngeal TB is
the most highly infectious form, but since most cases are associated with
far advanced open cavitary pulmonary disease, the infectivity of laryngeal
TB alone has not been clearly proven. In 2 patients with laryngeal TB
without pulmonary disease, no evidence of intrafamilial spread was found,
suggesting the laryngeal disease in itself may not be so infectious (1).
This moderator has been involved with a similar case in which isolated
laryngeal TB was diagnosed, and despite a delay in making the diagnosis, no
family and hospital spread was found.
Having a positive Mantoux skin test for TB, assuming that the test was
performed and read appropriately, reflects previous exposure to TB, not
necessarily active infection at that time. Individuals with a positive skin
test (2) have an approximately 10 percent chance of developing active
tuberculosis in their lifetimes, 5 percent in the 1st 2 years and 5 percent
afterwards. The risk of reactivation can be as high as 10 percent per year
in AIDS patients.
It is not clear how an estimate of 5-10 percent skin test reactivity after
this exposure for those shopping in the store is suggested, as infectivity
correlates with degree of exposure. Family and close friends having a high
degree of skin test reactivity (it is likely the case that none of them
have been found to have overt infection) does not necessarily suggest a
high degree of transmission to much more casual contacts in less confined
It was Robert Koch in 1891, following his identification of the human
tubercle bacillus, who felt that he could develop a cure for TB using a
filtrate of killed organisms (3). This was not to be the case, but testing
was found to be used as a diagnostic test, first observed by European
1. Horowitz G, Kaslow R, Friedland G: Infectiousness of laryngeal
tuberculosis. Am Rev Respir Dis 1976; 114:241-44.
2. Lutwick LI: Tuberculin skin testing. In, Tuberculosis, A Clinical
Handbook. Lutwick LI (ed), Chapam & Hall, London, UK, 1995.
3. Koch R. Weitere mitteilungen uber ein Heilmittel gegen Tuberculose.
Dtsch Med Wschr 1891; 17:101-102.
4. Snider DE: The tuberculin skin test. Am Rev Respir Dis 1982; 125
(Suppl): 108-18. - Mod.LL]