we used statewide reported ntm isolate data from all laboratories in oregon collected during 20072012 . from these data ,
we defined disseminated ntm as a reported ntm isolate from blood , cerebrospinal fluid , bone marrow , lymph node , or other sterile site in an oregon resident > 18 years of age . in a sensitivity analysis
, we expanded this definition to include isolates from nonsterile sites , specifically skin and urine , that could still represent disseminated disease . to identify cases of
hiv - associated disseminated ntm , we linked patients with ntm isolates to the statewide hiv surveillance registry by name , date of birth , and sex using registry plus link plus ( 10 ) .
we reviewed all possible matches manually . to calculate incidence , exposure time began with the date of hiv diagnosis .
we censored cases at death , ntm diagnosis , or 1 year after the last reported cd4 or viral load result when the gap was > 2 years between laboratory tests . since 2006
, oregon law has required that laboratories report all cd4 counts and viral loads to the oregon health authority .
we calculated exposure time within cd4 ranges for each interval between reported cd4 counts until patients were censored .
we calculated disseminated ntm incidence by cd4 count ( closest to ntm diagnosis within preceding 3 months ) and year with 95% cis under the poisson distribution in sas version 9.4 ( 11 ) .
we identified 37 disseminated ntm cases among a population of 7,349 hiv - infected patients with 33,072 person - years of exposure ; most were male ( 28 , 75.7% ) , non - hispanic ( 29 , 78.4% ) , and white ( 26 , 70.3% ) , with a median age of 40.0 years ( range 22.759.4 years ) ( table 1 ) .
median time from hiv diagnosis to disseminated ntm was 2.1 years ( range 020.7 years ) .
most cases were caused by mac ( 35 , 94.6% ) ; 19 patients ( 52.8% , 1
outcome missing ) died , with median survival of 0.3 years ( range 05.8 years ) after ntm diagnosis .
median cd4 count and viral load collected closest to ntm diagnosis were 10 cells / mm and 131,446 copies / ml , respectively . at the time of ntm isolation , 23 ( 74.2% )
patients had cd4 counts < 50 cells / mm , 5 ( 16.1% ) had cd4 counts 5099 cells / mm , 1 ( 3.2% ) had a cd4 count 100199 cells / mm , and 2 ( 6.5% ) had cd4 counts > 200 cells / mm .
of the 2 patients with cd4 counts > 200 cells / mm , both had previous cd4 counts > 200 cells / mm ; 1 had an undetectable viral load , and the other had persistent viremia > 200,000 copies / ml . the patient with a cd4 count of 100199 cells / mm at the time of disseminated ntm diagnosis had a cd4 count of 32 cells / mm 9 months before diagnosis .   cd4 testing frequency varied substantially in the 6,171 patients with reported cd4 counts during 20072012 .
median time between cd4 count tests for those with testing intervals < 2 years was 76 days ( range 0664 days ) .
six patients with disseminated ntm did not have cd4 counts during the 3-month period before diagnosis and were excluded from cd4-specific incidence .
the highest incidence of disseminated ntm ( 5,300/100,000 person - years ) occurred in patients with cd4 counts < 50 cells / mm ( table 2 ) .
annual incidence ranged from 50/100,000 to 200/100,000 person - years ( median 110/100,000 ) , with no statistically significant difference over the 6 years . *
an additional 10 cases of possible disseminated ntm infections were identified ( 4 skin , 1 wound , 1 urine , 2 abscess , 2 unknown site ) .
species included mac ( 7 ) , mycobacterium xenopi ( 1 ) , and unspeciated ( 2 ) .
all 10 cases occurred in white men of median age 45.2 years ( range 32.062.8 years ) .
the 9 cases with cd4 test results ( 1 did not have a cd4 test within 3 months of the study ) were distributed evenly among the other 3 cd4 count groups ( median 135 cells / mm , range 92352 cells / mm ) .
limited studies have evaluated the incidence of disseminated ntm disease in persons with hiv in the haart era ( 7,9 ) .
we evaluated the complete population of oregon residents with hiv and ntm during 20072012 by merging 2 comprehensive statewide databases .
estimated annual incidence ( 0.11/100 person - years ) was lower than estimates previously described in the haart era ( 0.252/100 person - years ) ( 9,12 ) . during our study period ,
32% ( n = 1,996 ) of oregon s hiv - infected population had > 1 cd4 count < 200 cells / mm and 10.9% ( n = 677 ) had > 1 cd4 count < 50 cells / mm , indicating a relatively small population at theoretic risk for disseminated ntm .
of the 677 patients at highest risk , with > 1 cd4 count < 50 cells / mm , disseminated ntm developed in only 3.4% .
mortality rates from disseminated ntm remain high , with median survival and mortality rates similar to those shown in data reported previously ( 4,6,7,12 ) .
most studies evaluating disseminated ntm are limited to patients with cd4 counts < 99 cells / mm ; however , nightingale et al .
found that 7% of patients with a previous aids - defining illness and disseminated ntm disease had cd4 counts > 99 cells / mm ( maximum 441 cells / mm ) ( 4 ) .
our findings are consistent with this and suggest that disseminated ntm should be considered in this population .
oregon is a state with a relatively low hiv prevalence ( 143.1 cases/100,000 persons during 20072012 ) , with a range of 7179 hiv deaths annually and an average of 256 new cases yearly ( 13 ) .
our data might have limited generalizability beyond oregon , given that most patients living with hiv in oregon have access to care ; 87% of all patients in care have a suppressed viral load , and only 16% of aids drug assistance program clients lack reported recent cd4 or viral load test results ( 13 ) .
analysis of incidence by cd4 count was also limited by variability in frequency of laboratory testing , which was determined by the treating clinicians .
six ( 16% ) patients with disseminated ntm did not have cd4 counts taken 3 months before or 1 month after diagnosis . in addition , laboratory results could have been missing in oregon residents who receive hiv care outside the state .
our clinical data were limited to laboratory results ; therefore , we were unable to analyze the impact of antiretroviral therapy , antimicrobial prophylaxis or treatment , and access to care . given the rarity of this infection in our cohort , we suspect that prophylaxis is routinely being used in those with cd4 count < 50 cells / mm ; however , mortality rates continue to be high in those in whom disseminated ntm infections develop .
 we determined disseminated nontuberculous mycobacteria incidence in the hiv - infected population of oregon , usa , during 20072012 by using statewide laboratory surveillance . 
 we identified 37 disseminated nontuberculous mycobacteria cases among 7,349 patients with median annual incidence of 110/100,000 hiv person - years and the highest incidence in those with cd4 counts < 50 cells / mm3 ( 5,300/100,000 person - years ) . 
The Study
Conclusions