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M.L. Antunes, A. Fonseca-Antunes
Directorate-General of Health, Lisboa, Portugal.
Historical background
Portugal built its first tuberculosis (TB) hospital in Funchal, Madeira,
in 1862. In 1899, Queen Amelia proposed and sponsored a private foundation,
with clinics, hospitals, sanatoriums and preventoria, where relatives
and other contacts of TB patients were admitted for monitoring and treatment
if required. The foundation became a public institution in 1946. The fight
against TB has always enjoyed political, social, and public acceptance
and generous funding, with all services, including the newest drugs, being
provided free of charge: streptomycin was introduced in 1949, rifampicin
in 1966, and short course chemotherapy in 1979.
Epidemiological surveillance began in 1951. The system evolved from
a manual process to a punch card system and then to a rudimentary computer
program using a mainframe computer. Standardised reporting included patient
identification with place of residence, site of disease, radiological
appearance in the pulmonary cases, bacteriological status, classification
by previous treatment, results of BCG vaccination and Mantoux testing,
and outcome of disease. As TB cases were treated in the national health
system, and rarely in the private sector, the figures were valid and representative
of the epidemiological situation. It was believed that over 95% of the
patients diagnosed and treated were reported.
The TB prevention programme was formally integrated into the
primary health care system in 1984, but this has not been entirely successful.
The statutory notification system was retained and still represents comprehensive
data on all diagnosed patients. Annual reports have been published since
1988 (1).
In 1991 a computer program was developed to improve the existing system
(2), using World Health Organisation (WHO) definitions. This program allowed
more detailed information about the cases, quicker and easier exchange
of information, and the possibility of correcting the TB programme.
National guidance for the treatment of TB specifies a national drug
regimen with three to four drugs, isoniazid, rifampicin, pyrazinamide/ethambutol
or streptomycin (HRZ /E or S) given daily under supervision, where possible,
in the first two months, followed by four months of isoniazid and rifampicin
(HR) given daily or intermittently. Some variations of the basic
regimen are considered. Diagnoses are made by bacteriological examination
of smears and cultures; detailed identification is performed for
every case but the sensitivity of the organism is tested only for patients
who require repeat treatment and those for whom treatment fails, defined
as a positive smear after five months of treatment. There is a national
reference laboratory, which is mainly responsible for quality control,
but also tests some samples. Histological examination of biopsies
is considered in extrapulmonary cases. Prevention of TB in Portugal consists
of BCG vaccination, according to the WHO Expanded Programme on Immunisation,
at birth, on school entry at 5 to 6 years, and 11 to 13 years of age for
those whose Mantoux tests are negative. The TB prevention programme also
includes the screening of contacts and risk groups, and chemoprophylaxis
for children under 5 years of age. Screening of contacts has always been
incomplete and chemoprophylaxis is rarely used. Evaluation of the
TB prevention programme is in progress, but has been slow to implement.
TB remains a public health problem in some parts of Portugal despite
the many assets the fight against it has enjoyed. A mean annual decline
of 9% was observed in the late 1960s and early 1970s (1). The revolution,
social upheaval, and the massive influx of about 500 000 citizens from
the former colonies of Africa in poor health and socioeconomic conditions,
coming from regions with a high prevalence of TB, increased the number
of cases in 1975 and subsequently (figure 1), although proper treatment
regimens, adequate drug supply, and specific guidelines remained as permanent
features of the national programme.
TB in Portugal in 1994
In 1994, TB in five coastal provinces - Aveiro, Braga, Lisboa, Porto,
and Setúbal - accounted for 75% of the 5619 cases in Portugal overall,
cases in Lisboa and Porto made up 25% of the national total (figure
2). TB was less common in the inner provinces, where there were very few
cases in children.
Sixty-five per cent of TB cases in 1994 were males. The age specific
incidence was highest in young adults, as in the developing world, but
the incidence was also high in older people, as is found in developed
countries. The age distribution has been similar for the past five years
(figure 3).
National BCG coverage of newborn babies rose to 91% in 1994 alongside
improvements in other childhood indicators. The incidence of TB in children
aged 14 years or under, was 21/100 000 population compared with an overall
national rate of 51/100 000.
Sixty-three per cent of cases overall and 74% of pulmonary cases were
bacteriologically confirmed. The incidence of smear positive cases was
23/100 000 nationwide, with a rate of 24/100 000 in Lisboa and 37 in Porto.
Porto represented the worst epidemiological situation in the country,
with very high rates in some city boroughs and in some poor fishing and
declining industrial communities. Epidemiological analysis indicated the
existence of undisclosed sources of infection in these communities, responsible
for continuing transmission despite a cure rate of 83% in the district.
Relapses accounted for about 10% of all cases, as in previous years.
In children under 5 years one case of miliary TB and seven cases of TB
meningitis were diagnosed in 1994. One case was fatal. Overall, 15 cases
of TB meningitis occurred in children under 15 years, compared with five
cases in both 1992 and 1993. Cases of TB meningitis increased by a factor
of 1.6 in all age groups and miliary TB doubled overall with the increase
noted specially in males aged 25 to 44 years, who accounted for 50% of
the cases. These cases were mainly AIDS related, since TB and HIV are
closely linked in Portugal. TB occurred in 54% of the 567 AIDS cases diagnosed
in 1994, 15% of the 1256 TB cases in Lisboa, the district most affected
by the AIDS epidemic, were HIV positive. Most cases of dual infection
were males (82%) aged 25 to 44 years, 52% of whom were drug users, 24%
heterosexuals, and 21% homo/bisexuals, whereas the proportions of these
respective groups in AIDS cases unrelated to TB were 40%, 33%, and 21%.
Active TB accounted for 242 deaths, a case fatality rate of 2.5/100
000, most of whom were adults over 55 years of age.
Cohort analysis showed a cure rate of 71% nationwide, 3.8% were lost
to follow up, and 1.3% became chronic cases.
A prospective study of drug resistance began in 1995, proposed and sponsored
by WHO. Preliminary results of 634 patients evaluated, showed that 3.5%
of Mycobacterium tuberculosis shows multidrug resistance (at least
to isoniazid and rifampicin).
Conclusions
Misplanned, incomplete integration of the TB prevention programme into
the primary health care system, under the 1975 and 1984 health reforms,
may account for the delay in overcoming the problem of TB, which is also
related to slow economic recovery from the African war effort and to migration
into overcrowded slums of the large coastal cities. As TB remains an important
health problem in Portugal, it calls for a strong public health intervention
at local and district levels in the most affected areas, particularly
in the districts of Porto and Lisboa.
References
1. Direcção-Geral da Saúde. Tuberculose em Portugal,
1993. Lisboa, 1994.
2. Serra T, Lopes H, Salema A, Antunes ML. Tuberculosis surveillance
and evaluation system in Portugal. Tuber Lung Dis 1992; 73:
345-8.
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