HomeMy WebLinkAbouttuberculosis-in-alameda-county-2018-archivePATIENT DEMOGRAPHICS
Similar to previous years, a majority of TB cases were
male (61.0%). During 2018, the largest proportion of
TB cases occurred among adults 45 to 64 years old
(35.1%), and the lowest proportions occurred among
children 5 to 14 years old (1.3%) (Table 1).
OVERVIEW
During 2018, 154 tuberculosis (TB) cases were reported
to Alameda County (excluding the City of Berkeley).
The 2018 TB case rate in Alameda County was 10.0 cas-
es per 100,000 residents, a 24.2% increase from the
2017 rate. The 2018 rate ranks third among all jurisdic-
tions in California and is 1.9-fold higher than the Cali-
fornia state rate of 5.3 cases per 100,000 residents. Com-
pared to other Bay Area jurisdictions, the Alameda
County rate ranks lower than San Francisco (13.2 per
100,000), and higher than Santa Clara (8.6 per 100,000),
San Mateo (7.9 per 100,000), Solano (6.6 per 100,000),
and Contra Costa (5.2 per 100,000) counties.
Figure 2: Incident TB Cases (2018)
by Place of Birth, Alameda County
Figure 1. Tuberculosis Cases and Rate per 100,000
in Alameda County, 2009-2018
The majority of 2018 TB cases (95.3%) occurred among non-White residents (Table 1). From 2016 to 2018, Asian/
Pacific Islander (API) residents in Alameda County had an average annual case rate of 22.9 cases per 100,000 residents,
followed by Hispanic residents at 4.5 cases per 100,000 residents.
During 2018, 90.3% of TB cases were born outside of the U.S. (Table 1). The most frequent birthplaces outside of the
U.S. remain the Philippines, India, China, Vietnam, and Mexico (Figure 2). The 2016-2018 average annual case rate for
cases born outside of the U.S. was 24.5 per 100,000, 16 times the rate for cases born in the U.S. (1.5 per 100,000). For
2018 cases born outside of the U.S., 61.2% had resided in the U.S for 10 years or more before being diagnosed with
TB.
The largest proportion of 2018 TB cases occurred among residents of Oakland (36.4%), Fremont (18.2%) and San
Leandro (11.0%). Five-year average rates were highest in Downtown and East Oakland, and South Fremont (over twice
the five-year county average of 8.8 per 100,000) (Figure 3).
Table 1. Number of Incident TB Cases and Annual Average
Case Rates per 100,000, Alameda County
Tuberculosis Fact Sheet
Alameda County 2018
China, 12.3%
India, 16.2%
Philippines,
19.5%Vietnam,
9.1%
Mexico,
6.5%
Other,
26.6%
United
States, 9.1%
Unknown,
0.6%
156 177 132 136 114 108 139 135 124 154
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# Cases Alameda County California U.S.
Number of
2018 Cases
(N=154)Percent
Average Case
Rate per 100,000
(2016-2018)
Sex Males 94 61.0%11.0
Females 60 39.0%7.0
Age Group 0-4 yrs 3 1.9%*
5-14 yrs 2 1.3%*
15-24 yrs 13 8.4%6.6
25-44 yrs 39 25.3%7.5
45-64 yrs 54 35.1%10.9
65+ yrs 43 27.9%21.0
Black / African American 11 7.1%*
Asian / Pacific Islander 116 75.3%22.9
Amer Ind / Native AK 3 1.9%*
Hispanic / Latino 17 11.0%4.5
White 5 3.2%*
Birthplace United States 14 9.1%1.5
Outside of United States 139 90.3%24.5
* Categories with <10 average annual cases are unstable and not presented
Race /
Ethnicity
CLINICAL CHARACTERISTICS
Of all 2018 TB cases, 77.2% had any pulmonary in-
volvement and 22.7% were extrapulmonary only
(Table 2). Of all pulmonary cases, a majority (58.0%)
were acid-fast bacilli (AFB) smear-negative and
68.9% did not have evidence of cavitary disease on
chest radiography. Only 1.3% of 2018 TB cases were
co-infected with HIV. The most common comorbidi-
ty was diabetes (26.6%).
DRUG RESISTANCE
More drug-resistant isolates were identified among
culture-positive cases during 2018 compared to 2015-
2017 (20.0% vs. 4.8%-11.5%). During 2018, 25 TB
cases were resistant any TB treatment drug, and 24 to
at least one first-line treatment drug (isoniazid, rifam-
pin, ethambutol or pyrazinamide). Sixteen (64.0%)
were resistant to isoniazid only. Alameda County had
three multidrug-resistant TB cases (resistant to both
isoniazid and rifampin) in 2018, compared to one in
2017.
DIAGNOSTIC TESTING
Among 2018 TB cases with any pulmonary disease,
73.9% received a nucleic acid amplification (NAA)
test at diagnosis, a higher proportion than among
2017 cases (61.5%). Similar to 2017, more 2018 cases
with positive sputum AFB smears received NAA
tests compared to patients with negative sputum AFB
smears (89.4% and 62.3%, respectively); a larger pro-
portion of 2018 cases with negative sputum AFB
smears received a NAAT test compared to 2017
(62.3% and 38.2%, respectively).
SUMMARY
TB remains an important public health problem in
Alameda County, where the case rate ranks third
among all jurisdictions in California. Preliminary anal-
yses suggest that the higher case rate in 2018 was not
P a ge 2 T u b e r c u l o s i s F a c t S h e e t
1000 San Leandro Blvd, First Floor, San Leandro, CA 94577
Phone: (510) 667-3096 | Fax: (510) 273-3916
http://www.acphd.org/tb.aspx
Last updated March 20, 2019
For questions or additional information, contact:
Alameda County Public Health Department
Tuberculosis Control Section
due to increases among clinical cases or as a result of
recent transmission. A large proportion of Alameda County TB cases continue to occur among older adults, those born
outside of the U.S., and non-U.S.-born cases who have been in the U.S. for 10 years or more before TB diagnosis; all
are known risk factors for latent TB infection (LTBI). Reports have also indicated that 80%-85% of all TB cases are
due to LTBI reactivation. Therefore, identifying and treating LTBI is a key TB control strategy. TB Control also contin-
ues to encourage early diagnosis through the use of NAA tests, as this practice may facilitate earlier TB treatment initia-
tion and reduce disease transmission.
Figure 3: Average Annual TB Rates per 100,000 by Zip Code
(2014-2018), Alameda County
Number Percent
Pulmonary only 88 57.1%
Extrapulmonary only 35 22.7%
Both 31 20.1%
Sputum smear Positive 47 39.5%
Negative 69 58.0%
Not done 3 2.5%
Cavitary disease Present 37 31.1%
Absent 82 68.9%
Comorbidities HIV/AIDS 2 1.3%
Diabetes 41 26.6%
End-stage renal disease 8 5.2%
Other immunosuppression*7 4.5%
25 20.0%
Resistance to INH only 16 12.8%
Resistance to PZA only 3 2.4%
1 0.8%
2 1.6%
Multidrug resistance 3 2.4%
Sputum smear positive (N=47)NAAT performed 42 89.4%
NAAT positive 41 97.6%
Sputum smear negative (N=69)NAAT performed 43 62.3%
NAAT positive 21 48.8%
* Due to a medical condition, such as hematologic or reticuloendothelial malignancies or
immunosuppressive therapy, such as prolonged use of high-dose adrenocorticosteroids.
Table 2: Clinical & Laboratory Characteristics of TB Cases (2018)
Alameda County
Among cases with any pulmonary disease (N=119)
Site of disease
Among cases with any pulmonary disease and sputum smear performed
(N=88)
Nucleic Acid
Amplification
Testing (NAAT)
practice at
diagnosis
Drug resistance
among culture-
positive cases
Resistance to any TB medications
Resistance to INH and any other non-first-line
medication
Resistance to Streptomycin only