Publications

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are thought to be associated with--and perhaps to mediate--accelerated loss of lung function in COPD. Although the application of culture-independent methods for detection of bacteria have shown COPD to be associated with marked differences in the burden, diversity, and composition of the bronchial bacterial microbiome, few studies have examined the changes associated with community-acquired exacerbations of the disease. In a longitudinal cohort study of COPD, the availability of sputum samples from subjects obtained at the onset of an exacerbation and during periods of clinical stability before and after the event enabled us to recently address this gap in knowledge, using culture-independent, 16S rRNA-based analysis methods combined with in silico inference of metagenomic functions. We observed sputum bacterial composition to be generally stable over the preexacerbation period of clinical stability, but to change at the time of exacerbation, with specific enrichment in not only typical COPD-associated bacterial species (e.g., Haemophilus influenzae) but also other phylogenetically related species with pathogenic potential. Concurrently, we observed depleted abundance of other bacteria whose predicted metagenomes suggest functional capacities to produce a variety of antiinflammatory compounds. Most strikingly, we found that resolution of these exacerbation-related changes in sputum microbiota composition differed significantly, depending on the exacerbation treatments prescribed. Treatment with corticosteroids resulted in microbiome enrichment for a number of bacterial communities, mostly members of the Proteobacteria phylum, whereas prolonged suppression of microbiota was seen in those treated with antibiotics alone. Taken together, our findings suggest that exacerbations of COPD are associated with heterogeneous changes in the bronchial microbiome, with increases in the abundance of species related to typical COPD pathogens and decreases in microbiota members that contribute to compositional and functional homeostasis. The findings further suggest that exacerbation treatments may have very different impacts on the bronchial microbiome's rate of return toward baseline composition.

BACKGROUND

Smoking cessation treatment service is concerned to be a critical element in methadone maintenance treatment (MMT) in order to diminish the effect of smoke on health outcomes. To implement the smoking cessation services in Vietnam, we examined the stages of change to quit and determined associated factors among MMT patients.

METHODS

We conducted a cross-sectional survey with 1016 MMT patients in five clinics in Hanoi and Nam Dinh province, of those, 932 (91.7%) were ever-smokers. Patients were classified into four groups: "pre-contemplation," "contemplation," "preparation," and "action and maintenance" by using the transtheoretical model. Multivariate logistic regression was applied to determine the associated factor for intention and action to quit smoking.

RESULTS

Overall, 96% were not actively trying to quit or maintain abstinence. Age older than 45, HIV-positive status, and residence in Hanoi were negatively associated with intention to quit. Meanwhile, higher levels of nicotine dependence and number of years of smoking negatively associated with quitting and abstinence.

CONCLUSIONS

The study indicated the high rate of MMT smokers being in pre-contemplation stage but low proportion of quitting and maintaining abstinence. It emphasizes the importance of availability and accessibility of information about smoking cessation therapies and services. Integrating cessation programs into health-care services should be considered to provide tailored interventions for different patient groups.