Rev Saúde Pública 2007;41(Supl. 1)
Ana Luiza BierrenbachI
Adriana Bacelar Ferreira
GomesI
Tuberculosis incidence and cure
rates, Brazil, 2000-2004
Elza Ferreira NoronhaII
Maria de Fátima Marinho de
SouzaI
ABSTRACT
OBJECTIVE: To describe the geographical distribution of tuberculosis
incidence rates based on a set of epidemiological and operational indicators
from information system database.
METHODS: Data from the Sistema de Informação de Agravos de Notificação
(Brazilian Information System for Tuberculosis Notification) were collected
after removal of improper repeat records and record linkage. Tuberculosis
incidence rates were estimated according to geographical unit, age group, sex,
clinical manifestation and treatment schedule and standardized for population
age group distribution based on 2000 Population Census.
RESULTS: In 2004, in Brazil, tuberculosis incidence rate was 41 per 100,000
inhabitants and 74,540 new cases were notified. Of these, 52.8% were pulmonary
tuberculosis with positive bacilloscopy, 24.1% were under supervised treatment,
63.5% were from state capitals or metropolitan areas, and 54.9% were cured
cases (complete treatment). After records with missing outcome data were
excluded, cure rates were 72.4% for new cases, 47% for new HIV-positive
cases, 64.9% for relapses, 64.5% for transfers in/out, and 40% for returns
after default. Cure rate for new cases under supervised treatment was 77.1%.
A higher proportion of records with missing outcome information was seen
in recent years.
CONCLUSIONS: Different incidence rates and treatment outcomes were
found in different Brazilian states. To reach the 85% cure goal for new cases
and to increase cure in HIV-positive and defaults cases additional efforts are
needed by the Brazilian National Tuberculosis Program, including scaling up
the Directly Observed Therapy Strategy.
KEY WORDS: Tuberculosis, epidemiology. Incidence. Diseases
registries. Epidemiology, descriptive. Brazil.
INTRODUCTION
I
Secretaria de Vigilância em Saúde.
Ministério da Saúde. Brasília, DF, Brasil
II
Faculdade de Medicina. Universidade de
Brasília. Brasília, DF, Brasil
Correspondence:
Ana L Bierrenbach
Esplanada dos Ministérios, Bloco G
Edifício Sede, 1º andar, sala 150
70058-900 Brasília, DF, Brasil
E-mail:
[email protected]
Received: 1/30/2007
Approved: 3/27/2007
Tuberculosis (TB) has historically been a public health concern worldwide.
As part of the global strategy for TB morbidity and mortality reduction, the
World Health Organization (WHO) established a goal of 70% detection of all
new bacillary (BK) TB cases and 85% treatment success.7 According to current
WHO estimates, in Brazil, 110,000 new TB cases are reported every year, i.e.,
an incidence rate of 62 per 100,000 inhabitants, and Brazil ranks 15th of the
22 most affected countries.7
In order to achieve internationally established TB control goals it is central for
the Brazilian Ministry of Health National Program for Tuberculosis Control
(PNCT) to have available instruments for analysis of data collected in the epidemiological surveillance system to support evidence-based actions.
2
METHODS
For data analysis of TB incidence between 2000 and
2004 data from the Sistema de Informação de Agravos
de Notificação (Sinan – Brazilian Information System
for Tuberculosis Notification), obtained in February
2006, was used after removal of improper repeat records
and record linkage.
New TB cases were defined according to Sinan guidelines.* Notification rates were estimated for TB
incident cases and referred as incidence rates. Rates
were estimated by geographical unit, age group,
sex, TB clinical form and treatment schedule. Two
different age classification were used, the first was
divided into four age groups (children [0–19 years],
young adults [20–39 years], adults [40–59 years]; and
elderly [over 60 years]) and the second into 11 age
groups (0 to 4 years; 5 to 9 years; 10 to 14 years; 15
to 19 years; 20 to 29 years; 30 to 39 years; 40 to 49
years; 50 to 59 years; 60 to 69 years; 70 to 79 years;
and 80 years or more). The following geographical
units were included in the study: regions, states, 36
metropolitan areas, state capitals and 315 priority
municipalities defined in PNCT working program for
2004–2007. TB incidence rates were standardized for
age distribution in Brazilian states according to the 2000
Population Census.
The number of cases by geographical unit was estimated based on local case notification except for
estimates of incidence rate, which were based on case
municipality of residence.
Bierrenbach AL et al.
Age groups (years)
Incidente rate per 100,000
0 20 40 60 80 100
The objective of the present study was to describe the
geographical distribution of TB incidence using a set
of epidemiological and operational indicators from
information system database.
Tuberculosis and cure rates
2000
2001
Male 60+
Fem 60+
Male 40-59
Fem 40-59
Male 20-39
Fem 20-39
Male 0-19
Fem 0-19
2002
Year
2003
2004
Figure. Tuberculosis incidence rates (all clinical forms) by
gender and age group. Brazil. 2000–2004.
exclusively in state capitals. These proportions were
distinct in the Brazilian regions (Table 2).
The proportion of Brazilian municipalities where not
even a single TB case was notified over the study period
was variable. It more remarkably decreased between
2000 and 2002 and then remained at 25%. Overall,
municipalities where no TB case was notified had small
populations. In 2004, 26% of them did not notify any
TB case. However, only 1% had a population of 20,000
inhabitants or more. Ponta Grossa (state of Paraná), a
PNCT priority municipality, was the single city with
more than 100,000 people where no TB cases were
notified in 2004.
Table 3 shows new cases, relapses, returns after default,
transfers in/out and changes in diagnosis by year of
notification. Cases in each category did not vary significantly by year of notification. More than 84% of
notifications in all years were new cases, and a portion
of these diagnoses were changed and no longer were
TB cases throughout follow-up.
After progressively adding up the number of new TB
cases and incidence rate in Brazil for 2000–2003, in
2004, it was found slight case reduction with a total of
74,540 new cases and incidence rate of 41 per 100,000
inhabitants. The observed rates are below WHO estimated rates for Brazil, i.e., 110,000 new cases per year
and incidence rate of 62 per 100,000 inhabitants. New
pulmonary cases and BK pulmonary cases remained
relatively steady around 85.6% and 53.1%, respectively, over the study period (Table 1).
The Figure shows the annual TB incidence rate (all
clinical forms) by sex and age groups. A reduction
in incidence rates was seen in younger age groups in
contrast to increased rates in older age groups. Although
there was only slight time variation in each category, a
difference could be seen. In men, incidence increased
with age while in women it increased in children and
young adults but remained constant in those aged 20 to
39 years or more. In 2004, incidence rates were similar
in both male and female children (risk ratio=RR=1.1),
increased in young adult (RR=1.7) and adult males
(RR=2.4), and decreased in elderly males (RR=2.2).
In 2004, 75.2% of new cases were notified in 315
priority municipalities, 63.5% in capitals and other
municipalities forming metropolitan areas and 43.4%
With respect to clinical manifestations, in 2004, pulmonary TB was the most prevalent form in all age
groups. There was 3% of mixed (pulmonary and extra-
RESULTS
* Ministério da Saúde. Secretaria de Vigilância em Saúde. Sistema de Informação de Agravos de Notificação. Normas e rotinas. Brasília; 2004.
(Série A: Normas e Manuais Técnicos).
3
Rev Saúde Pública 2007;41(Supl. 1)
pulmonary) TB form; ganglionar TB among total new
cases was higher up to 14 years of age; and pleural
TB increased during childhood and then remained
relatively steady. Bone and miliary forms were also
more prevalent in children and then declined during
adolescence. The proportions were similar in the remaining years studied.
When only TB cases with HIV co-infection were
analyzed, more than 50% of cases had pulmonary TB
in all age groups. However, when compared to total
cases, HIV-infected TB cases comprised a higher proportion of extra-pulmonary cases, i.e., more than 20%
in all age groups.
Table 4 shows outcome of new cases by year of notification. Cure rate was 68.8% in 2000 and 54.9% in 2004
without removing cases with missing outcome information from the analysis. New cases with missing outcome
information increasingly grew over the period studied,
which indicates a delay in case follow-up notification. It
can also be noted that, while lower than in more recent
years, in the year 2000, there were still notified new
cases with missing outcome information. Therefore,
after removing from the analysis notifications with
missing outcome information, cure rates were 73.3%
and 72.4% in 2000 and 2004, respectively.
Outcomes were different depending on case status. New
BK cases with or without HIV co-infection had higher
cure rates than total new cases. Cure rates of new cases
with HIV co-infection, relapses and returns were lower
than those found for total new cases and cure rate of
returns was lower than relapses and even lower than
that found in HIV-infected TB cases. Death among new
HIV-infected TB cases was about three times higher
than that seen in total new cases. Relapses and returns
had greater missing outcome data. Defaults were about
three times higher for cases previously returning after
default compared to total new cases (Table 5).
Information on treatment schedule (supervised or selfadministered) is still scarce nationwide. This data was
missing in 30.9% of new cases, 37.9% of relapses and
36.4% of returns. Table 6 shows higher cure rates and
lower default and transfer rates for new cases receiving
supervised treatment. A larger number of cases with
missing outcome information was seen in records
where data on treatment schedule was unknown or
missing; and a larger number of deaths was found in
supervised compared to self-administered treatment
cases. Table 6 also shows outcomes of returns after
default by treatment schedule. Similarly to new cases,
returns under supervised treatment showed higher cure
and death rates as well as lower defaults compared to
Table 1. TB incidence and incidence rate per 100,000 inhabitants (all forms, pulmonary and BK pulmonary) per year of
notification. Brazil, 2000–2004.
Incidence
Year
Total new
cases
Rates*
New pulmonary cases
N (%)
BK+ N (%)
New cases
New pulmonary cases
BK+
2000
70,086
60,407 (86.2)
37,560 (53.6)
41.3
35.6
22.1
2001
70,384
60,312 (85.7)
37,260 (52.9)
40.8
35.0
21.6
2002
72,516
61,925 (85.4)
38,402 (53.0)
41.1
35.1
21.8
2003
75,416
64,412 (85.4)
40,269 (53.4)
42.1
36.0
22.5
2004
74,540
63,632 (85.4)
39,373 (52.8)
41.0
35.0
21.7
Source: Sinan
* Excluded records with missing sex, age or code of residence municipality.
BK: bacillary.
Table 2. Number and proportion of new TB cases (all forms) notified in capitals, capitals or other municipalities of metropolitan
areas and priority PNCT municipalities. Brazil, 2004.
Region
North
Northeast
Total
Priority municipality
N (%)
Metropolitan area
N (%)
Capital
N (%)
6,949
5,123 (73.7)
4,224 (60.8)
3,901 (56.1)
21,582
14,739 (68.3)
11,808 (54.7)
9,840 (45.6)
Midwest
3,162
2,047 (64.7)
1,604 (50.7)
1,517 (48.0)
Southeast
34,179
28,578 (83.6)
24,321 (71.2)
14,606 (42.7)
South
8,668
5,587 (64.5)
5,406 (62.4)
2,508 (28.9)
Brazil
74,540
56,074 (75.2)
47,363 (63.5)
32,372 (43.4)
Source: Sinan
4
Tuberculosis and cure rates
returns under self-administered treatment. However,
regardless of treatment schedule, cure was seen in about
half of return cases and default was three times as high
when compared to new cases.
States and regions share to the total number of cases
was quite similar except in the states of Minas Gerais
and Amapá, where incidence rates significantly increased over the study period. In 2004, 45.9% of new
cases were notified in the Southeastern region, 29% in
Northeastern, 11.6% in Southern, 9.3% in Northern and
4.2% in Midwestern region. Table 7 shows crude and
standardized rates (estimated based on municipality of
residence) for each state and region. In most Brazilian
states there was a difference between the number of
cases notified and the number of residents; for instance
in the Federal District where there were 36.4% more
notified cases than residents. In 2004, those states with
more new cases were São Paulo, Rio de Janeiro and
Bahia whereas those with higher standardized rates
were Amazonas, Rio de Janeiro, and Roraima.
Nationwide, 25% of new cases did not undergo sputum
bacilloscopy for diagnosis in 2004. This proportion was
27.1% in the Southeastern region, 24.9% in Southern
and Northeastern regions, 22.1% in Midwestern, and
Bierrenbach AL et al.
16% in Northern region. It is possible that the ratio of
BK cases compared to total new cases may have been
affected by the percentage of tests not performed:
53.1% nationwide, ranging from 60.7% in the Northern
region to 50.1% in the Southeastern region.
The distribution of new cases according to HIV testing
was different in Brazilian regions in 2004; more than
75% of cases in Northern and Northeastern region
were not tested for HIV. The proportion of cases
with ongoing HIV testing was high, above 10%, in
all regions and as high as 26.8% in the Southeastern
region. Southern and Southeastern regions shower
higher percentage of cases with HIV (either positive
or negative) results available, 50.5% and 40.6% respectively. While the Northern region had the lowest
percentage of cases with results available (9%), it
showed the highest rate of positive cases (35%). Of all
cases with HIV results available, 24.2% were positive
nationwide.
The distribution of new cases by treatment schedule
was significantly different in all regions in 2004. Southeastern region had the lowest proportion of cases
under supervised treatment (14.6%) and the highest
with unknown treatment schedule (51.9%). The Mi-
Table 3. Category of TB cases notified by year of notification. Brazil, 2000–2004.
Category
2000
N (%)
2001
N (%)
2002
N (%)
2003
N (%)
2004
N (%)
New case
70,086 (84.6)
70,384 (86.8)
72,516 (87.6)
75,416 (89.3)
74,540 (89.9)
Relapse after cure
5,983 (7.3)
5,330 (6.6)
4,842 (5.8)
3,947 (4.7)
3,274 (4.0)
Return after default
4,679 (5.6)
2,896 (3.6)
2,303 (2.8)
1,810 (2.1)
1,525 (1.8)
838 (1.0)
698 (0.8)
1,663 (2.0)
1,667 (2.0)
2,047 (2.5)
1,212 (1.4)
1,287 (1.6)
1,377 (1.7)
1,565 (1.8)
1,423 (1.7)
54 (0.1)
534 (0.6)
107 (0.1)
38 (0.1)
45 (0.1)
81,129
82,808
Transfer in/out
Change in diagnosis*
Missing data
Total
82,852
84,443
82,854
Source: Sinan
* Change in diagnosis is one category of case outcome variable. The values were subtracted from the categories of the
respective variable in database.
Table 4. Outcome of new TB cases. Brazil, 2000–2004.
Outcome status
Cure
2000
N (%)
2001
N (%)
2002
N (%)
2003
N (%)
2004
N (%)
47,676 (68.0)
47,133 (67.0)
47,782 (65.9)
49,286 (65.4)
40,887 (54.9)
Default
8,674 (12.4)
8,146 (11.6)
7,291 (10.1)
7,033 (9.3)
5,563 (7.4)
Death
4,562 (6.5)
4,254 (6.0)
4,437 (6.1)
4,651 (6.1)
4,277 (5.7)
Transfer in/out
4,158 (6.0)
4,090 (5.8)
4,601 (6.3)
5,502 (7.3)
5,640 (7.6)
MRTB*
Missing data
Total
17 (0.0)
19 (0.0)
4,999 (7.1)
6,742 (9.6)
70,086
70,384
Source: Sinan
* MRTB: Multiresistant tuberculosis
51 (0.1)
8,354 (11.5)
72,516
51 (0.1)
8,893 (11.8)
75,416
60 (0.1)
18,113 (24.3)
74,540
5
Rev Saúde Pública 2007;41(Supl. 1)
Table 5. TB case distribution by outcome and categories. Brazil, 2004.
Outcome
status
New case
Cure
New HIV
case
N (%)
New BK
pulmonary
case**
N (%)
N (%)
New
HIV BK
pulmonary
N (%)
Relapse
Return
Transfer
in/out
N (%)
N (%)
N (%)
40,887 (54.9)
35,205 (55.3)
1,849 (34.8)
637 (37.0)
2,649 (46.0)
1,750 (28.0)
1,156 (53.7)
Default
5,563 (7.4)
4,934 (7.8)
537 (10.1)
186 (10.8)
554 (9.6)
1,499 (24.0)
176 (8.2)
Death
4,277 (5.7)
3,561 (5.6)
954 (18.0)
294 (17.1)
390 (6.8)
403 (6.4)
85 (4.0)
Transfer in/out
5,640 (7.6)
4,704 (7.4)
591 (11.0)
197 (11.4)
469 (8.2)
699 (11.2)
369 (17.2)
MRTB*
Missing data
60 (0.1)
55 (0.1)
3 (0.1)
1 (0.1)
23 (0.4)
21 (0.3)
18,113 (24.3)
15,173 (23.8)
1,379 (26.0)
408 (23.6)
1,670 (29.0)
1,888 (30.1)
74,540
63,632
5,313
1,723
5,755
6,260
Total
6 (0.3)
360 (16.6)
2,152
Source: Sinan
*MRTB: Multiresistant tuberculosis
** BK: bacillary
Table 6. Outcome by treatment schedule for new TB cases and returns after default. Brazil, 2004.
Desfecho
Cure
New cases N (%)
Returns after default N (%)
Yes
No
Unknown
Total
Yes
No
Unknown
Total
11,108 (61.9)
19,740 (58.9)
10,039 (43.5)
40,887 (54.9)
459 (31.8)
781 (30.8)
510 (22.4)
1,750 (28.0)
Default
1,227 (6.8)
2,772 (8.3)
1,564 (6.8)
5,563 (7.5)
318 (22.0)
688 (27.1)
493 (21.7)
1,499 (23.9)
Death
1,029 (5.7)
1,572 (4.7)
1,676 (7.3)
4,277 (5.7)
94 (6.5)
127 (5.0)
182 (8.0)
403 (6.4)
Transfer
in/out
1,024 (5.7)
2,770 (8.3)
1,846 (8.0)
5,64 (7.6)
173 (12.0)
262 (10.3)
264 (11.6)
699 (11.2)
19 (0.1)
38 (0.1)
3 (0.0)
60 (0.1)
4 (0.3)
16 (0.6)
1 (0.0)
21 (0.3)
MRTB*
Missing
data
Total
3,553 (19.8)
17,960 (24.1)
6,629 (19.8)
33,521 (45)
7,931(34.4)
18,113 (24.3)
396 (27.4)
655 (26.2)
827 (36.3)
1,888 (30.2)
23,059 (30.9)
74,540 (100)
1,444 (23.1)
2,539 (40.5)
2,277 (36.4)
6,260 (100)
Source: Sinan
dwestern region had the highest proportion of cases
under supervised treatment (40.2%).
Regions differed regarding outcome of new cases. The
85% cure of new cases was not seen in any clinical
form. The Southeastern region had the lowest cure rate
(39.3%) possibly due to the large number of new cases
with missing outcome information.
The states of Rio de Janeiro, São Paulo and Rio Grande
do Norte had higher unknown or missing outcome data
and thus had the lowest cure rates. The states of Acre,
Roraima, Sergipe and Espírito Santo had 80% or more
of cure of new cases. Roraima was the single state
to reach cure rates above 85% for new cases despite
the small proportion of cases with missing outcome
information.
Outcomes of cases diagnosed in 2004 in metropolitan
areas showed also a heterogeneous pattern for both
total new cases and new BK cases. Comparison was
hindered between metropolitan areas due to different
proportion of cases with missing outcome information.
Of all new cases, including those with missing outcome
information, the metropolitan areas of Natal (RN), Vale
do Aço (MG), Baixada Santista (SP) and Rio de Janeiro
(RJ) had cure rates lower than 31%. In the regions of
Núcleo and Expansão do Vale do Itajaí (SC), northern
and northeastern Santa Catarina (SC), Vitória (ES) and
Expansão de Tubarão (SC) 80% or more cure rate was
found. Considering only new BK cases, including those
with missing outcome information, besides the aforementioned regions, the metropolitan areas of Núcleo
de Tubarão (SC) and Petrolina/Juazeiro (PE) had also
cure rates of 80% or more.
Table 8 shows that all regions had higher proportion of
outcome fields left blank in new cases under supervised
than self-administered treatment. Of total new cases
notified, cure rate of cases under supervised treatment
were higher than those found for self-administered
treatment cases in the Northern and Northeastern regions but were similar in Southeastern, Southern, and
Midwestern regions.
6
Tuberculosis and cure rates
DISCUSSION
The study of TB morbidity and mortality in Brazil is
based on data from information health systems managed by the Brazilian Ministry of Health and, in recent
years, it has undertaken efforts to improve these information systems. TB morbidity data confirm adequate
coverage and quality of data from Sinan-TB allowing
in-depth epidemiological analyses by geographical
region comparisons. This information also supports
Bierrenbach AL et al.
decision making in PNCT management at country,
state and local level. As a result, regional and state
discrepancies and their effect in the analysis of case
outcomes became evident especially in the reporting
of follow-up variables.
The present study used a database from Sinan-TB after
removal of improper repeat records and record linkage. It provided lower number of new and retreatment
cases and higher cure rates compared to data based
Table 7. Number of new cases and crude and standardized TB incidence rates (all forms) in each region and state by year of
notification. Brazil, 2000–2004.
Region/State
North
2000
2004
Crude rate
Standardized rate*
Crude rate
Standardized rate*
57.5
47.1
53.8
49.7
Rondônia (RO)
37.5
41.2
35.4
40.6
Acre (AC)
57.8
70.9
44.8
53.5
Amazonas (AM)
72.8
86.4
69
83
Roraima (RR)
55.8
67.8
51.9
63.5
Pará (PA)
44.5
50.2
51.2
58.8
11
37.1
46.2
18.2
20.8
18
20
43.7
46.3
43.4
46
Amapá (AP)
Tocantins (TO)
Northeast
9
Maranhão (MA)
47.2
53.5
43.2
49.4
Piauí (PI)
35.8
38.8
35.5
38.3
Ceará (CE)
43.8
46.4
45.5
48.3
Rio Grande do Norte (RN)
39.4
40.6
37.4
38.8
Paraíba (PB)
34
35.1
31.1
32.2
Pernambuco (PE)
43.3
44.6
51
52.3
Alagoas (AL)
38.2
41.9
39
42.7
Sergipe (SE)
26.5
29
25.7
27.7
Bahia (BA)
51.2
54
47.2
49.8
43.3
41.3
43.6
41.5
0.3
0.2
27.2
26.6
Southeast
Minas Gerais (MG)
Espírito Santo (ES)
40.8
40.3
37.8
37.4
Rio de Janeiro (RJ)
90.7
85.6
79.7
74.8
São Paulo (SP)
45.8
43.4
38.2
36.1
31.8
30.4
32.8
31.6
Paraná (PR)
24.4
24
24.6
24.1
Santa Catarina (SC)
23.2
22.4
26.2
25.3
Rio Grande do Sul (RS)
43.2
40.9
44.1
41.7
28.6
29.3
24.3
25.2
39.9
40.6
39.1
40
South
Midwest
Mato Grosso do Sul (MS)
Mato Grosso (MT)
45
48.5
35.3
38.1
Goiás (GO)
20.5
21
16.7
17
Federal District (DF)
Brazil
17.1
17.4
14.8
16
41.3
41.2
41.6
41.5
* Direct standardization by age in Brazil according to 2000 Population Census.
7
Rev Saúde Pública 2007;41(Supl. 1)
Table 8. Outcome of new TB cases by treatment schedule and regions. Brazil, 2004.
Outcome
Cure
N (%)
Supervised
treatment
Death
Transfer
in/out
MRTB*
N (%)
N (%)
N (%)
N (%)
North
1,723 (70.2)
215 (8.8)
150 (6.1)
159 (6.5)
2 (0.1)
Northeast
5,030 (70.2)
524 (7.3)
363 (5.1)
400 (5.6)
Southeast
2,025 (40.5)
244 (4.9)
229 (4.5)
225 (4.5)
South
1,437 (69.6)
150 (7.3)
189 (9.1)
893 (70.3)
94 (7.4)
98 (7.7)
Brazil
11,108 (61.9)
1,227 (6.8)
1,029 (5.7)
North
2,477 (65.3)
331 (8.7)
175 (4.6)
682 (18.0)
Northeast
7,103 (66.7)
939 (8.8)
461 (4.3)
Southeast
4,686 (40.9)
817 (7.1)
336 (2.9)
Midwest
Self-administered
treatment
Default
Missing data
Total
N (%)
N
204 (8.3)
2,453
10 (0.1)
841 (11.7)
7,168
1 (0.0)
2,279 (45.6)
5,003
141 (6.8)
0 (0.0)
149 (7.2)
2,066
99 (7.8)
6 (0.5)
80 (6.3)
1,270
1,024 (5.7)
19 (0.1)
3,553 (19.8)
17,960
6 (0.2)
122 (3.2)
3,793
1,123 (10.6)
18 (0.2)
1,003 (9.4)
10,647
486 (4.3)
6 (0.1)
5,120 (44.7)
11,451
South
4,358 (72.1)
528 (8.7)
486 (8.0)
350 (5.9)
8 (0.1)
316 (5.2)
6,046
Midwest
1,116 (70.5)
157 (9.9)
114 (7.2)
129 (8.1)
0 (0.0)
68 (4.3)
1,584
19,740 (58.9)
2,772 (8.3)
1,572 (4.6)
2,770 (8.3)
38 (0.1)
Brazil
6,629 (19.8)
33,521
*MRTB: Multiresistant tuberculosis
on crude information. The analysis report of record
linkage/removal from Sinan-TB database is described
elsewhere.1 Whether or not to approve incidence rates
obtained after record linkage/removal process from
Sinan-TB database is under discussion in the Ministry
of Health. Its approval basically relies on the quality
(no improper repeat records) of database routinely sent
by municipalities to the central level.
Increased number of new cases notified in the period
2000–2003 can be partially explained by increased TB
notifications in Sinan. This is evidenced not only by
increased number of new cases notified in Minas Gerais
but also by a reduction in the ratio and population size
of municipalities where no cases were notified during
the period studied. The fact that a minority of large-size
municipalities did not have any case notification can
be suggestive of large – yet in small number – areas
of underreporting. This hypothesis needs further investigation in field studies, follow-up of new cases
in the next years and result analysis of other database
linkage studies.5 In addition, there is a need for studies
to explore spatial distribution of TB cases notified
in a municipality to locally detect potential areas of
underreporting.6 These studies are needed given the
discrepancy in the rate found in the present study and
WHO estimated rate (41 and 62 per 100,000 inhabitants, respectively).7 Brazilian Ministry of Health is
required to ascertain consistence and quality stability of
data from Sinan-TB regarding coverage, inexistence of
improper repeat records and data consistence in order
to properly request for a review of WHO estimates on
TB incidence rate in Brazil.
The period studied did not allow to evidence a reduction
of TB transmission in Brazil. However, the slightly
increasing number of new TB cases in younger age
groups can be regarded as an indirect evidence of
reduced transmission.2 This reduction is aligned with
the trend seen in aggregate data, which have been collected and analyzed by state health departments since
pre-Sinan implementation. In order to describe the
historical trend of TB morbidity in Brazil it is required
a comparison of recent data with data from 1980s and
1990s published by the Brazilian Ministry of Health
Surveillance Department.3,4
Moreover, it can be noted that 2004 data follows the
same trends seen over the last two decades: clustering
of TB cases in capitals, metropolitan areas and PNCT
priority municipalities, mostly in the states of São
Paulo and Rio de Janeiro; high incidence rates in Rio
de Janeiro and Amazon states; prevalence of pulmonary
forms especially in more advanced age groups; and
high prevalence of TB-AIDS comorbidity especially
in the Southeastern region.3,4,* The study sought to
stress differences in the proportions of each outcome
category when cases with missing outcome information
were included or not. These differences were even
more remarkable when results were broke down by
states. Cases with missing outcome information are
likely to have more defaults and transfers than cures.
Thus, to prevent bias while generalizing cases with
proper outcome record as representative of total cases,
it is key to epidemiologically ascertain there are no
differences between cases with and without missing
information.
* Ministério da Saúde. Secretaria de Vigilância em Saúde. Saúde Brasil 2005 - Uma análise da situação de saúde. Brasília; 2005.
8
Tuberculosis and cure rates
Bierrenbach AL et al.
Low cure rates of HIV-infected cases and returns after
default indicate the need for public policies specifically
targeting these populations. Directly Observed Treatment Strategy (DOTS) was implemented in Brazil by
the end of 1990s and this strategy has sought to bridge
this gap, yet inconsistently and primarily, in many
Brazilian municipalities.7 Data on DOTS coverage
are inconsistently collected and sometimes are simply
approximate estimates reported by local PNCT teams.
The methodological approach usually applied for estimating DOTS coverage in Brazil reports the number
of health units with at least one case under supervised
treatment.7 Furthermore, the only supervised treatment
variable from Sinan-TB database has almost one-third
of missing information and requires to be validated
for inclusion in epidemiological studies. This variable
reporting has become mandatory only by the end of
2004 in Sinan-TB version 6.0 but there is still the
option “unknown supervised treatment,” which means
non-reporting.
to establish parameters for further comparisons.
There may have been pre-selection of cases referred to
supervised treatment. This is probably due to the fact
that health units in Brazil do not have available providers generally trained for supervised treatment and/or
they are not available in sufficient number to meet the
needs. Outcome must be carefully interpreted for new
cases and returns under supervised or self-administered
treatment and study authors chose to present these data
In conclusion, wide differences were found between
states regarding incidence and outcome. In order to
achieve the cure goal for new BK cases and increase
cure rates of HIV-infected cases and returns additional
efforts are required by PNCT. They include surveillance
of cases aiming at increasing records with outcome
information and timely reporting as well as scaling up
directly supervised therapy strategy.
Missing information hinders description of TB-AIDS
cases as well. The study data reveal heterogeneity of
comorbidity cases in the different regions but the proportion of cases with no or “ongoing” HIV testing in
the Northern, Northeastern, and Midwestern regions
prevents actual comparisons and hinders the analysis
on current status of this comorbidity in Brazil. Linkage
studies of Sinan-TB database could bridge this gap.
Of all Brazilian states, Roraima was the single one to
achieve the goal of 85% cure for new BK cases established by WHO,5 despite missing outcome information in
some cases. Even in a small universe of cases, cure rate
achieved in this state is remarkable within the Brazilian
national system. Other states and some highly populated
metropolitan areas were also able to attain or come close
to this goal, indicating that the small number of cases
is not a determinant for this achievement.
REFERENCES
1. Bierrenbach AL, Stevens AP, Gomes ABF, Noronha
EF, Glatt R, Carvalho CN, et al. Efeito da remoção
de notificações repetidas sobre a incidência
da tuberculose no Brasil. Rev Saude Publica.
2007;41(Supl. 1):????
2. Chaimowicz F. Age transition of tuberculosis
incidence and mortality in Brazil. Rev Saude Publica.
2001;35(1):81-7.
3. Centro de Referência Prof. Hélio Fraga. Secretaria de
Vigilância em Saúde. Ministério da Saúde. Análise da
situação de tuberculose nos anos noventa e início da
década atual. Bol Pneumol Sanit. 2005;13(3):133-87.
4. Coordenação Nacional de Pneumologia Sanitária.
Reunião de avaliação operacional e epidemiológica
Note: See the Letter to the Editor in this Supplement.
do programa nacional de controle da tuberculose na
década de 80. Bol Pneumol Sanit. 1993; Spec No1:190.
5. Façanha MC. Tuberculose: subnotificação de casos
que evoluíram para óbito em Fortaleza-CE. Rev Bras
Epidemiol. 2005;8(1):25-30.
6. Souza WV, Albuquerque MFM, Barcellos CC, Ximenes
RAA, Carvalho MS. Tuberculose no Brasil: construção
de um sistema de vigilância de base territorial. Rev
Saude Publica. 2005;39(1):82-9.
7. World Health Organization. Global tuberculosis
control - surveillance, planning, financing.
WHO report 2005. Geneva; 2005. (WHO/HTM/
TB/2005.349).