US alarmed over rise in tuberculosis among immigrants

EDITOR- It was interesting to see the recent News extra article in
BMJ regarding tuberculosis (TB) among foreign-born people in the United
States. Charatan's article in News extra did bring to light the continuing
public health concern of TB among the foreign-born population of the
United States.1 However, some clarification of the facts given and the
terms used, and which might have led to incorrect conclusions, is needed.

The term immigrant is not accurately used in Charatan's article. It
has a strict definition for many countries, including the United States.
An immigrant is a person who is admitted into the United States as a
lawful permanent resident or who adjust his or her immigration status to
permanent resident. However, the U.S. Immigration and Naturalization
Service (INS) estimated that 5.0 million (range 4.6 to 5.4 million)
foreign-born people were residing in the United States unlawfully as of
October 1996.2 This was an increase of 1.1 million from the October 1992
estimate. California with 2.0 million, is the leading state of residence
for these undocumented people, followed by Texas (700,000), New York
(540,000), and Florida (350,000). Mexico is the leading country of origin
for these undocumented people, providing an estimated 2.7 million (54%)
people residing unlawfully in the United States.2 With this large influx
of undocumented entrants, the INS is responding with increased screening
of those who are apprehended and detained. Approximately 155,000 people
were placed in INS detention from October 1998 through September 1999
(fiscal year 1999 [FY99]). The Division of Immigration Health Services
(DIHS) of the U.S. Public Health Service (PHS) provides health care
support to the INS by screening detainees for TB at service processing
centers in the United States and its territories. Last fiscal year DIHS
screened more than 52,000 detainees who were held for at least 48 hours or
who manifested symptoms of TB (G Migliaccio, personal communication,
12/9/99). (Other INS detainees might have received TB screening while
housed in correctional systems not covered by DIHS.)

As stated previously, immigrants are those people arriving in the
United States for lawful permanent residence and those already in the
United States who adjust their immigration status to permanent residence.
These two groups have averaged totals of 400,000 each for the last few
years, with 380,700 new arrivals and 417,700 adjustments for FY97. In
addition, 69,300 refugees entered the United States during that same time
period.2 All immigrants and refugees by law must undergo a medical
examination before becoming permanent residents. The Division of
Quarantine (DQ) of the Centers for Disease Control and Prevention (CDC) of
PHS is responsible for writing the guidelines for that examination,
monitoring the physicians contracted to perform the examination overseas,
and notifying the receiving health departments of immigrants and refugees
found with possible TB conditions. A major component of the medical
examination is the identification of infectious TB (sputum smears showing
the presence of acid-fast bacilli [AFB]) and of possible TB disease (chest
radiograph having findings suggestive of active or inactive TB) that is
not infectious. Potential immigrants and refugees who are located overseas
and who have infectious TB must be treated until they are not infectious
(three sputum smears negative for AFB). Once treatment renders them
noncontagious for travel, they are allowed into the United States with
mandatory followup by the applicable health department after arrival.
Immigrants and refugees with possible noninfectious TB (chest radiograph
suggests active or inactive disease) are referred to local health
departments. DQ notifies local health departments in those areas where the
immigrants or refugees are resettling that they have arrived and have a
possible TB condition. From FY95 through FY97, DQ identified an average
of 14,000 immigrants and refugees annually entering the United States with
possible TB conditions and referred this information to local health
departments (DQ, CDC, unpublished data). Evaluations of immigrants and
refugees in the United States with possible active or inactive TB
identified on entry into the United States reflect follow-up rates of 88%
to 99% for active TB and 83% to 97% for inactive TB.3

More efforts are needed to reduce the rate of TB occurrence, but the
trends are in the right direction. In 1998, 7,591 (41%) of the 18,361 TB
cases in the United States were among foreign-born people. However, since
1995 the total number of foreign-born cases has decreased each year, from
7,930 to the current number of cases for 1998. From 1995 through 1998,
the rates of TB cases per 100,000 population for U.S.-born and foreign-
born people have decreased to the current rates of 4.4 per 100,000 and 28
per 100,000, respectively. In 1998, California reported the most TB cases
(5,382), followed by New York (4,574), Texas (2,510), and Florida (1,707).
Of the foreign-born cases, the majority come from Mexico (23%) which also
contributes the majority of immigrants (14%).4, 2

At DQ, we agree that we must continue our vigil to identify TB in all
sectors of society. CDC has established a priority for state and local
health departments to follow up and provide treatment, if appropriate, for
those immigrants and refugees identified during the overseas health
assessment as having possible active or inactive TB and for DQ to continue
forwarding their medical documentation to applicable health departments.5
The recent decline of TB among foreign-born people likely reflects
successes in TB screening and followup among the 900,000 immigrants and
refugees entering the United States annually. More effort is needed to
address the problem of TB among the 5.0 million undocumented people living
in the United States to ensure that all segments of our population receive
adequate screening, treatment, and prevention if we wish to control TB.

Susan T. Cookson
medical epidemiologist

Chief, Migration Health Assessment Section

Division of Quarantine, National Center for Infectious Diseases Centers
for Disease Control and Prevention

References:

1. Charatan F. US alarmed over rise in tuberculosis among immigrants.
BMJ 2000;320:140

2. U.S. Immigration and Naturalization Service. Statistical yearbook
of the Immigration and Naturalization Service, 1997. U.S. Washington, DC:
Government Printing Office; 1999.

3. Binkin NJ, Zuber PLF, Wells CD, Tipple MA, Castro KG. Overseas
screening for tuberculosis in immigrants and refugees to the United
States: current status. Clinical Infect Dis 1996;23:1226-32.

4. Centers for Disease Control and Prevention. Reported tuberculosis
in the United States, 1998. Atlanta: U.S. Department Health and Human
Services; August 1999.

5. Centers for Disease Control and Prevention. Recommendations for
prevention and control of tuberculosis among foreign-born persons report
of the working group on tuberculosis among foreign-born persons. MMWR
1998;47:1-26.