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Published Date: 2005-03-18 23:50:00
Subject: PRO/EDR> Mycobacterium bovis, cheese - USA (NY)(02)
Archive Number: 20050318.0785

MYCOBACTERIUM BOVIS, CHEESE - USA (NEW YORK)(02)
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International Society for Infectious Diseases
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[1]
Date: Tue, 15 Mar 2005
From: ProMED-mail <promed@promedmail.org>
Source: NYC Department of Health and Mental Hygiene [edited]
<http://www.nyc.gov/health>
[Replicated here with permission of Dr. Marci Layton]

2005 Health Alert 8: _Mycobacterium bovis_ in USA-born children
--------------------------------------------------
Since 2001, when universal genotyping of all culture positive tuberculosis
(TB) cases began, 35 cases of _M. bovis_ have been identified in NYC,
involving 22 (63 percent) adults and 13 (37 percent) children. 7 of these
cases (21 percent) due to _M. bovis_ have occurred in USA-born children <6
years old of Mexican-born parents; all had extra-pulmonary disease (lymph
node (5) or peritoneal (2)). One 15-month-old with _M. bovis_ peritonitis
died in Mar 2004 from complications of his disease. _M. bovis_ is most
commonly acquired through consumption of unpasteurized dairy products, and
is therefore unexpected in USA-born children who should not have access to
unpasteurized dairy products. In New York State, dairy products sold in
retail stores are pasteurized, and cattle are not infected with _M.
bovis_. Due to the unexpected presence of disease due to _M. bovis_ among
USA-born children, the New York City Department of Health and Mental
Hygiene (DOHMH) initiated an investigation of _M. bovis_ in NYC.
Among the 35 cases, countries of birth include Mexico (57 percent), US (31
percent), Dominican Republic (6 percent), Guatemala (3 percent) and Guyana
(3 percent). All adult cases are non-USA born, while 85 percent (11/13) of
pediatric cases are USA-born. However, 100 percent (11/11) of the USA-born
pediatric cases have Mexican-born parents, and 7/13 pediatric cases were <6
years old. Of the 35 cases, 21 percent were HIV positive (all adults) and
60 percent had extra-pulmonary disease only compared to 21 percent of
non-_M. bovis_ TB cases. Cases have occurred in all 5 boroughs of
NYC. All except 1 isolate have resistance to pyrazinamide; in addition, 43
percent have streptomycin resistance and 6 percent have other drug resistance.
As per the USA Census, from 1990-2000, the Mexican population in NYC
tripled (61 722 to 186 872); the number of cases of TB among Mexican-born
persons residing in NYC declined (52 in 1995 to 46 in 2004). Since 2001,
10 percent (20/196) of Mexican-born TB cases in NYC were due to _M. bovis_,
compared to <1 percent (15/4159) of TB cases in non-Mexicans. Among
children <6 years old, there were 105 TB cases in NYC from 2001-2004. 90
(86 percent) were among US-born children, and 31 (34 percent) of these were
culture-positive. In USA-born children <6 years old with culture-positive
TB, 7 of 31 cases (23 percent) were due to _M. bovis_. 15 (14 percent) of
105 TB cases among children <6 years old were in non-USA born children; 2
(13 percent) were culture-positive (neither [of these 2 cases was] _M.
bovis_) and 13 (87 percent) were culture-negative.
_M. bovis_ is part of _M. tuberculosis complex_, which also includes _M.
tuberculosis_, _M. bovis BCG, _M. africanum_, _M. microti_, _M. canetti_,
and _M. caprae_. It is distinguished from _M. tuberculosis_ by a number of
microbiological characteristics including pyrazinamide resistance;
genotyping techniques provide definitive identification. _M. bovis_ is
primarily a disease of cattle, but may affect other animals including deer,
goats, sheep, pigs as well as humans. (In humans, _M. bovis_ is a disease
very similar to tuberculosis, although site of disease is more often
extra-pulmonary.) The primary mode of transmission of _M. bovis_ is
through ingestion of unpasteurized dairy products produced with milk of
infected cattle. _M. bovis_ may also be transmitted by individuals with
pulmonary _M. bovis_ through aerosolization, as with _M. tuberculosis_,
although this occurs much less commonly than food-borne
transmission. Rarely, _M. bovis_ is transmitted through direct inoculation
as may occur when an open wound or laceration comes into contact with
infected animal products.
_M. bovis_ is unlikely to be present in dairy products produced in New York
State (NYS) or surrounding states. The bovine eradication program in the
USA began in 1917 and has greatly decreased the prevalence of _M. bovis_ in
cattle. Cattle in NYS are certified by the USDA as [_Mycobacterium_]
bovis-free, as are cattle in surrounding states of Connecticut and New
Jersey. In addition, dairy products in NYS are pasteurized with few
exceptions; a small numbers of dairies in NYS have special permits to sell
unpasteurized milk on-site to individuals for individual consumption (not
for resale), and these dairies must have increased surveillance for
diseases associated with unpasteurized dairy products, including _M. bovis_.
In NYC, courier services provide transport of food and other items to and
from NYC to Mexico. Most patients interviewed reported receiving foods
through these agencies, brought in luggage by family or friends from
Mexico, obtained products in Mexican grocery stores in NYC, some of which
sell unlabeled cheeses, or from door-to door vendors who may also sell
unlabeled dairy products. This cheese may be contaminated and
unpasteurized, as official Mexican government reports estimate that 16
percent of cattle in Mexico are infected with _M. bovis_, and approximately
30 percent of milk in Mexico is not pasteurized. The health department is
investigating whether these unlabeled products have been pasteurized and
from where they originate.
The NYC DOHMH is collaborating with the CDC, the USDA, the FDA, and the New
York State Department of Agriculture and Markets on this ongoing
investigation. We would also like to request that providers assist us.
Providers should report all suspected and confirmed cases of tuberculosis,
including disease caused by _M. bovis_, to the TB Hotline, (212) 788-4162
within 24 hours. A Universal Reporting Form (URF) must follow within 48
hours. A specimen for DNA analysis can be sent to the Public Health
Laboratory Services at 455 First Avenue, Room 136, New York, NY 10016. The
URF form can be faxed to the Bureau of Tuberculosis Control at (212) 788-4179.
All suspected cases of TB should be treated with a standard regimen of
isoniazid, rifampin, pyrazinamide, and ethambutol while awaiting culture
and susceptibility results. If susceptibility results reveal pyrazinamide
resistance and _M. bovis_ is confirmed, treatment with isoniazid and
rifampin should be continued for 9 months, unless other drug resistance is
identified. If culture negative TB is suspected in Mexican-born children
or US-born children of Mexican parents, _M. bovis_ should be included in
the differential diagnosis and consideration should be given to prolonging
therapy for 9 months for presumed disease caused by _M. bovis_ with
pyrazinamide resistance.
In addition to _M. bovis_, other food-borne pathogens may be associated
with unpasteurized dairy products, including _Listeria monocytogenes_,
_Brucella_, _Clostridium botulinum_, _Salmonella_, _Staphylococcus aureus_,
and _Escherichia coli_. Primary care providers should inform patients from
areas where dairy products may be contaminated with _M. bovis_ about the
health risk of consuming unpasteurized dairy products. Infants, children,
pregnant women, the elderly and those with weakened immune systems are at
especially high risk for foodborne illness, particularly listeriosis, and
should avoid eating foods that contain raw, unpasteurized milk such as
Mexican-style soft cheese.
[Byline: Sonal Munsiff, MD and Ann Winters, MD Bureau of TB Control]
******
[2]
Date: Tue, 15 Mar 2005
From: ProMED-mail <promed@promedmail.org>
Source: FDA.gov [edited]
<http://www.fda.gov/bbs/topics/news/2005/NEW01165.html>

FDA Issues Health Advisory About Certain Soft Cheese Made From Raw Milk
-------------------------------------------------
The Food and Drug Administration (FDA) is advising that some soft cheeses
made with raw milk present a health risk, especially to high risk groups,
such as pregnant women, newborns, older adults, and people with weakened
immune systems. Such raw milk soft cheeses can cause several serious
infectious diseases including listeriosis, brucellosis, salmonellosis and
tuberculosis.
Recently, cases of tuberculosis in New York City have been linked to
consumption of queso fresco style cheeses, either imported from Mexico or
consumed in Mexico, contaminated with _Mycobacterium bovis_, the causative
agent.
The raw milk soft cheeses of most concern can originate from Mexico and
Central American countries. Queso fresco style cheese, which is soft and
white, has been found to be the most popular kind of cheese among the
Hispanic community and can include Queso Panela, Asadero, Blanco and
Ranchero, among other styles and may be imported or produced in the USA.
FDA recommends that consumers do not eat any unripened raw milk soft
cheeses from Mexico, Nicaragua, or Honduras. Data show that they are often
contaminated with pathogens. FDA further recommends that consumers not
purchase or consume raw milk soft cheeses from sources such as flea
markets, sellers operating door-to-door or out of their trucks or shipped
or carried in luggage to them from Mexico, Nicaragua, or Honduras. This
includes cheeses made at home by individuals.
FDA further advises that there is some risk of infection from a number of
pathogenic bacteria for anyone who eats raw milk soft cheese from any source.
--
ProMED-mail
<promed@promedmail.org>
[These reports are the official health alert from NYC and the posting from
the FDA.
One of the hallmarks of _Mycobacterium bovis_ and the BCG vaccine strains
(derived from _M. bovis_) is resistance to pyrazinamide. The pncA
(pyrazinamidase) gene involved in bacterial activation of pyrazinamide
contains in _M. bovis_ a point mutation that renders pyrazinamidase unable
to catalyze drug activation to produce the drug's active metabolite,
pyrazinoic acid. However, rare strains of _M. bovis_ may be sensitive to
the drug, as noted in the following publication and an excerpt from its
abstract:
Niemann S, Richter E, Rusch-Gerdes S: Differentiation among members of the
_Mycobacterium tuberculosis_ complex by molecular and biochemical features:
evidence for two pyrazinamide-susceptible subtypes of _M. bovis_. J Clin
Microbiol 2000;38:152-7.
"The variations in biochemical as well as molecular characteristics among
several members of the _Mycobacterium tuberculosis_ complex that are not
_M. tuberculosis_ have been assessed to facilitate an unambiguous species
identification. Altogether, 96 _M. tuberculosis_ complex strains including
52 _M. bovis_ isolates and 44 _M. africanum_ isolates were analyzed by
spoligotyping.
The strains could be clustered into 5 spoligotype groups. All _M. bovis_
isolates showed the typical absence of the spacers 39 to 43 and typical
biochemical properties. However, within these strains we found a group of
strains that had a spoligotype pattern which is clearly defined by the
additional absence of spacers 3 to 16 and that were uncommonly susceptible
to pyrazinamide (PZA). This spoligotype pattern has previously been
described as being typical for a caprine genotype because of its
predominant isolation from sheep and goats. Due to the clinical importance
of PZA resistance, we propose 2 _M. bovis_ subtypes: _M. bovis_ subtype
bovis, which is resistant to PZA, and _M. bovis_ subtype caprae, which is
susceptible to PZA [Now known as _M. caprae_].
2 additional strains that clustered in group 3 showed biochemical and
genetic properties typical for _M. bovis_ and were also sensitive to PZA;
thus, they may represent a 3rd PZA-susceptible _M. bovis_ subtype." - Mod.LL]

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