The international epidemiology of disseminated Mycobacterium avium complex infection in AIDS. International MAC Study Group.
OBJECTIVE
To determine rates of disseminated Mycobacterium avium complex (MAC) infection among AIDS patients in developed and developing countries, and to determine whether different rates reflect differences in exposure or immunity, or both.


METHODS
Prospective cohort study.


METHODS
University hospitals and outpatient AIDS programs.


METHODS
HIV-infected subjects with CD4 counts < 200 x 10(6)/l were interviewed and had CD4 lymphocyte counts, blood cultures for mycobacteria (baseline and at 6 months), and skin tests with purified protein derivative (PPD) and M. avium sensitin.


RESULTS
Among 566 study patients rates of disseminated MAC were 10.5-21.6% in New Hampshire, Boston and Finland compared to 2.4-2.6% in Trinidad and Kenya (P < 0.001). PPD skin test reactions > or = 5 mm were present in 20% of patients from Kenya compared to 1% at other sites (P < 0.001). Among patients from the United States and Finland, multiple logistic regression indicated that occupational exposure to soil and water was associated with a decreased risk of disseminated MAC, whereas the following were associated with an increased risk of disseminated MAC: low CD4 count, swimming in an indoor pool, history of bronchoscopy, regular consumption of raw or partially cooked fish/shellfish and treatment with granulocyte colony-stimulating factor.


CONCLUSIONS
Rates of disseminated MAC in AIDS are higher in developed than developing countries and are due to both differences in exposure and differences in immunity. These data provide a rationale for prevention of MAC through both active immunization and reduction in exposure to the organism.
Fordham von Reyn
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C
Infectious Disease Section, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03756, USA.
Arbeit
R D
RD
Tosteson
A N
AN
Ristola
M A
MA
Barber
T W
TW
Waddell
R
R
Sox
C H
CH
Brindle
R J
RJ
Gilks
C F
CF
Ranki
A
A
Bartholomew
C
C
Edwards
J
J
Falkinham
J O
JO
O'Connor
G T
GT
D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology*; D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008875:Middle Aged; D015999:Multivariate Analysis; D009162:Mycobacterium avium / Q000302:isolation & purification*; D011446:Prospective Studies; D012307:Risk Factors; D014300:Trinidad and Tobago / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000209:etiology