STUDY On the Production Dynamics of Infectant Aerosols in Patients With Pulmonary Tuberculosis and Factor Analysis associated with His Production
Name: TALINE CANTO TRISTÃO
Publication date: 12/09/2018
Advisor:
Name |
Role |
|---|---|
| MOISES PALACI | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| FABÍOLA KARLA CORRÊA RIBEIRO | External Examiner * |
| LILIANA CRUZ SPANO | Internal Examiner * |
| MOISES PALACI | Advisor * |
Summary: Believed to be a producer of cough aerosols capable of being more effective in
assessing infectivity than sputum smear examination and culture of sputum
mycobacteria, since it is a more important reflex process of the respiratory tract.
Fennelly et. al., (2004) carried out a first study with the fact that the aerosols generated
by patients from patients with active and untreated pulmonary tuberculosis (TB) are
considered and can be useful, quantified and measured through the projection of A
Cough Aerosol Sampling System (CASS). The results reported show isolation of
aerosol bacilli, the four gases of the 16 enrolled, containing infectors of diameter
between 0.65 and 4.7 μm. In their third study, Fennelly (JONES-LÓPEZ et. al., 2013)
classified, through CASS, the following index cases: low aerosol (55%), low infectious
aerosol (1-9 CFU) (19%) and a high infectious aerosol producer (≥ 10 CFU) (26%),
which provided 8% (20/254), 8% (7/90) and 18% (18/98) of conversion in their
contacts, respectively. Patients classified as negative aerosol, obtained a conversion
index of their respective groups along the IC under aerosol, were able to manifest
intermittently with respect to the environment. It is speculated that the infective
particles of these volunteers were not detected by the fact that in both studies,
volunteers were submitted to only one CASS harvest. In this context, the objective was
to study the dynamics of the production of infective aerosols in patients with pulmonary
TB and to analyze factors associated with their production. Bacteriological analysis of
spontaneous sputum of volunteers with pulmonary TB was performed through Acidfast bacilli smear, semiquantitative culture, quantitative culture, and evaluation of
pulmonary function by spirometry methods and maximal forced expiratory flow
measurement. The classification and quantification of the aerosols generated by the
cough were given through 4 CASS harvests, with 2 coughing periods of 5 minutes.
Mycobacterium tuberculosis was isolated from the cough-generated aerosols of 12 of
the 16 patients enrolled, accounting for 75% of the total, which we call "CASS positive
patients" and 4 patients (25%) who did not isolate Mtb, CASS patient not detectable ".
There was no association between the extent of disease and the ability to generate
infectious aerosols; the variables, coughing effort, cough frequency and FEFmax are
not relevant in relation to the ability to generate infectious aerosols; no association was
identified between positive through Acid-fast bacilli smear, culture and Xpert MTB /
RIF® results and the ability to produce infective aerosols; due to the different Mtb
isolation standards in the 4 CASS harvests, we adopted the following classification:
constant positive CASS patient; intermittent positive CASS (PI) patient and constant
non-detectable CASS patient (NDC). Thus, according to the classification adopted,
most of the volunteers were classified as CASS PI, equivalent to 10 of the 16
volunteers enrolled in the study, 2 were classified as CASS PC and 4 were classified
as CASS NDC; for the classification and quantification of the infectious particles
generated by the cough of patients with pulmonary TB, only 3 CASS crops are
required.
