2. HISTORIA DE LA TUBERCULOSIS (TB)
La TB es una
enfermedad antigua
identificada (por PCR)
como TB espinal en
momias egipcias.
La historia data de los
años 1550 – 1080 A.C.
7. Panorama Mundial de Resistencia
9.27 millones de casos de TBC en el mundo en
el año 2007.
510.545 (5%) casos de MDR-TB.
25 países (17 de los cuales están en el Este de
Europa) reportan el 85% de todos los casos.
Solo el 6% de los casos de MDR-TB fueron
notificados por test de sensibilidad.
40.000 casos anuales de XDR-TB.
Global tuberculosis control - epidemiology, strategy, financing; WHO Report 2009.
8. MDR-TB en casos nuevos, 1994 - 2009
World Health Organization. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010
Global Report on Surveillance and Response (WHO/HTM/TB/2010.3). 2010.
9. MDR-TB en casos que han sido tratados
previamente, 1994 -2009
World Health Organization. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010
Global Report on Surveillance and Response (WHO/HTM/TB/2010.3). 2010.
10. Global tuberculosis control - epidemiology, strategy, financing; WHO Report 2009.
Test de susceptibilidad para casos nuevos y retratamiento.
(número de países que reportaron datos, porcentaje del total
de casos estimados de MDR-TB notificados por los países)
11. Resistencia en Colombia.
925 pacientes no tratados presentaron una prevalencia de
resistencia global de 11,78% (IC 95%: 9,86-14,02) y una MDR-
TB de 2,38% (IC 95%: 1,58-3,57).
Los 264 pacientes previamente tratados presentaron una
resistencia global de 44,32% (IC 95%: 38,45-50,35) y MDR-TB
de 31,44% (IC 95%: 26,14-37,27).
MDR-TB en el grupo de pacientes previamente tratados:
50,6% en los fracasos, 25,3% en los abandonos y 19,3% en
las recaídas.
Biomédica 2008;28:319-26
12. Países que han reportado al menos un
caso de XDR-TB, Junio 2010
World Health Organization. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010
Global Report on Surveillance and Response (WHO/HTM/TB/2010.3). 2010.
13. Factores de Riesgo
Asociación entre MDR-TB en recaídas vs. Casos nuevos
en países con vigilancia continua de TB resistente .
Recaídas.
Sexo?
~ Co-infección
con VIH.
World Health Organization. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010
Global Report on Surveillance and Response (WHO/HTM/TB/2010.3). 2010.
14. ¿Por qué es importante?
Mayor período de tratamiento (24 meses vs. 6-8
meses).
Menores tasas de curación.
Mayor mortalidad.
Mayor uso de fármacos de 2da línea:
• Mayor toxicidad.
• Mayores costos.
Wells CD et al: HIV infection and multidrug-resistant tuberculosis: the perfect storm. J Infect
Dis 196 Suppl 1:S86, 2007
15. M.
tuberculosis
silvestre
Cepa
resistente a
algún fármaco
Resistencia
Adquirida
Resistencia
Primaria
Mutación espontánea
Terapia inadecuada, pobre adherencia
o suministro de medicamentos.
Transmisión: Retraso en el diagnóstico,
hacinamiento, control inadecuado, VIH.
NATURALEZA
HUMANO
Lambregts-van Weezenbeek, CSB, Veen J.
Control of drug-resistant tuberculosis.
Tubercle Lung Dis 1995;76:455-459
Int J tuberc Lung Dis
13(11):1320-1330; 2009 The
Union
22. Totally drug-resistant strains (TDR)
or super XDR-TB isolates.
“MDR-TB strains that are resistant to all second-line drug
classes that our laboratory tested (ie, aminoglycosides,
cyclic polypeptides, fluoroquinolones, thioamides, serine
analogues, and salicylic acid derivatives).”
Chest 2009;136;420-425; Prepublished online April 6, 2009.
9.27 millones de casos de TB en el 2007 en el mundo
De esos, 1.37 millones (14.8%) eran VIH positivo
Solo el 6% de los casos de MDR-TB fueron notificados por DST.
Los países que reportaron datos de DST, solo alcanzaron el 47% del número total de casos nuevos de MDR.TB y el 60% para los casos previamente tratados.
Años 2004 - 2005
Colombia reportó su primer caso de XDR TB en el 2007
Given the large proportion of missing data, it has
not been possible to conclude whether an overall association
between MDR-TB and HIV epidemics exists.
However, based on the current data, HIV-positive
TB patients in three Eastern European countries (Estonia,
Latvia and the Republic of Moldova) appear to
be more at risk of harbouring MDR-TB strains. This
finding concurs with the results of the earlier reported
survey conducted in Ukraine (6). Furthermore, in
Lithuania – where drug resistance data could not be
disaggregated by HIV-negative and unknown HIV status
– HIV-positive TB patients had a 8.4 (95% CI: 2.7–
28.2) times higher odds of harbouring MDR-TB strains
than TB patients for whom HIV status was unknown,
indicating a possible association of the two epidemics.
In addition, preliminary results of a survey conducted
in Mozambique in 2007 have also found a significant
association.
Lack of an association between HIV status and
MDR-TB in some settings can be due to low numbers of
HIV-positive TB patients or patients with MDR-TB and
consequent insufficient power in analysis. This may be
a result of lack of testing of patients or of incomplete
reporting of results.
There are several reasons why drug-resistant TB may
be associated with HIV. Firstly, people living with HIV
in Eastern Europe – particularly those infected earlier
in the epidemic and whose weakened immune systems
have since left them vulnerable to TB – frequently come
from socially vulnerable populations, including injecting
drug users. Socio-behavioural problems and/or lack
of access to proper care may make these populations, as
TB patients, vulnerable to developing drug resistance as
a result of poor adherence to treatment or suboptimal
treatment. Furthermore, people living with HIV may
also be more likely to be exposed to MDR-TB patients,
due either to increased hospitalizations in settings
with poor infection control or association with peers
who may have MDR-TB, including in penitentiary settings.
In addition, acquisition of rifampicin resistance
among people living with HIV under treatment for TB
may also be the result of anti-TB drug malabsorption,
which has been documented in patient cohorts in settings
of high HIV prevalence.
The epidemiological impact of HIV infection on the
transmission of MDR-TB is still unclear and may depend
on several factors. HIV-positive TB cases are more
likely to be sputum smear negative, and therefore less
likely to transmit TB. In addition, delayed diagnosis of
drug resistance and unavailability of treatment (particularly
in previous years) have led to high death rates in
people living with HIV, which may also result in a lower
rate of TB transmission. On the other hand, people living
with HIV progress more rapidly to TB disease, and
in settings where MDR-TB is prevalent (either among
the general population or in a specific population such
as a hospital or a district), this may lead to rapid development
of a pool of drug-resistant TB patients.
Although there appears to be an association between
drug-resistant TB and HIV infection in some Eastern
European countries, the data are still limited to be able
to determine whether there is an overlap between the
MDR-TB and HIV epidemics worldwide. Unfortunately,
the continuous surveillance data in this report come
only from two regions, the European Region and the
Region of the Americas, and no data are reported from
countries with the highest prevalence of HIV infection.
It is critical to include HIV testing in drug resistance
surveys and in routine surveillance efforts in order to
better understand the relationship between the two
epidemics, which is key for optimal care of patients
