Incidence Of Smear-positive Tuberculosis Research Articles

Local spatial variations analysis of smear-positive tuberculosis in Xinjiang using Geographically Weighted Regression model

BackgroundThe spatial interplay between socioeconomic factors and tuberculosis (TB) cases contributes to the understanding of regional tuberculosis burdens. Historically, local Poisson Geographically Weighted Regression (GWR) has allowed for the identification of the geographic disparities of TB cases and their relevant socioeconomic determinants, thereby forecasting local regression coefficients for the relations between the incidence of TB and its socioeconomic determinants. Therefore, the aims of this study were to: (1) identify the socioeconomic determinants of geographic disparities of smear positive TB in Xinjiang, China (2) confirm if the incidence of smear positive TB and its associated socioeconomic determinants demonstrate spatial variability (3) compare the performance of two main models: one is Ordinary Least Square Regression (OLS), and the other local GWR model.MethodsReported smear-positive TB cases in Xinjiang were extracted from the TB surveillance system database during 2004–2010. The average number of smear-positive TB cases notified in Xinjiang was collected from 98 districts/counties. The population density (POPden), proportion of minorities (PROmin), number of infectious disease network reporting agencies (NUMagen), proportion of agricultural population (PROagr), and per capita annual gross domestic product (per capita GDP) were gathered from the Xinjiang Statistical Yearbook covering a period from 2004 to 2010. The OLS model and GWR model were then utilized to investigate socioeconomic determinants of smear-positive TB cases. Geoda 1.6.7, and GWR 4.0 software were used for data analysis.ResultsOur findings indicate that the relations between the average number of smear-positive TB cases notified in Xinjiang and their socioeconomic determinants (POPden, PROmin, NUMagen, PROagr, and per capita GDP) were significantly spatially non-stationary. This means that in some areas more smear-positive TB cases could be related to higher socioeconomic determinant regression coefficients, but in some areas more smear-positive TB cases were found to do with lower socioeconomic determinant regression coefficients. We also found out that the GWR model could be better exploited to geographically differentiate the relationships between the average number of smear-positive TB cases and their socioeconomic determinants, which could interpret the dataset better (adjusted R 2 = 0.912, AICc = 1107.22) than the OLS model (adjusted R 2 = 0.768, AICc = 1196.74).ConclusionsPOPden, PROmin, NUMagen, PROagr, and per capita GDP are socioeconomic determinants of smear-positive TB cases. Comprehending the spatial heterogeneity of POPden, PROmin, NUMagen, PROagr, per capita GDP, and smear-positive TB cases could provide valuable information for TB precaution and control strategies.

Trend in the incidence of smear-positive tuberculosis in a district in South India after DOTS implementation.

One baseline and three repeat surveys of the prevalence of tuberculosis (TB) disease were conducted in 1999-2008 in rural South India, where the DOTS strategy was implemented in 1999. The impact of DOTS on prevalence was documented, but not its impact on incidence. To ascertain epidemiological trends in the incidence of smear-positive TB. All persons aged ⩾15 years (range 83 000-92 000) were examined using chest radiography (CXR); chest symptoms and history of anti-tuberculosis chemotherapy were noted in all four surveys. Sputum was collected from eligible participants and tested using direct smear and culture, and for drug susceptibility. As follow-up surveys were not frequent, survey cases and cases directly notified under DOTS were combined to estimate the incidence of smear-positive TB. Coverage was consistently high in all the repeat surveys, at ⩾80% for CXR and symptom recording, and at ⩾95% for sputum examination. The annual incidence of smear-positive TB was respectively 112, 80 and 76 per 100 000 population in 2001-2003, 2004-2006 and 2006-2008. The overall decline observed was 7.5% per annum. A well-implemented DOTS strategy can lead to a reduction in the TB burden in the community.

Trend in the incidence of smear-positive tuberculosis in a district in South India after DOTS implementation

Trend in the incidence of smear-positive tuberculosis in a district in South India after DOTS implementation

STUDY OF THE STATUS OF TUBERCULOSIS CONTROL PROGRAM BASED ON THE IMPLEMENTATION OF THE DIRECTLY OBSERVED TREATMENT SHORT-COURSE STRATEGY (DOTS).

Introduction:Ascendant trend of tuberculosis in the world introduces this disease to be one of the most important infectious diseases in the world. So that every year, 9 million people are afflicted to active TB and about 5.1 million people die of the disease. As the HIV contaminated cases are increased, emergence and spread field of Multidrug-resistant tuberculosis (MDR-TB) bacilli has been provided.Objective:This study aimed to assess the Tuberculosis Control Program from 2005 to 2012 to determine the overall situation of disease epidemiology and prioritized strategies in disease control program within the south of Tehran.Materials and Methods:This cross-sectional study was extracted and analyzed retrospectively on the basis of records of all TB patients in TB health center and TB software in south Tehran in 2005-2012 years.Results:From the total population under protection of health center of south Tehran, 99% are urban and 1% are rural. During 2005-2012, 1242 TB cases have been registered and they were treated by DOTS method. There were 553 cases of new smear-positive pulmonary TB (44%), 222 cases of smear-negative pulmonary TB (18%) and 336 cases of extra-pulmonary tuberculosis (27%), 26 cases of recurrence (2%) and 11 cases of MDR (0.9%). Smear-positive pulmonary tuberculosis has included 67.4% of all tuberculosis patients.Conclusions:The results showed that, in accordance with TB worldwide statistics, at the health center of south Tehran, pulmonary TB is the most common form of the disease (67.4%). The incidence of smear-positive tuberculosis and all forms of TB cases has been an ascending trend over the period between 2005 and 2012.

Application of ARIMA model in forecasting monthly incidence of smear-positive tuberculosis

Objective To investigate the variation of the monthly incidence of smear-positive tuberculosis with time in Chongqing,so to provide a scientific evidence for the control and prevention of tuberculosis.Methods Using the SPSS 13.0software,we established an ARIMA model with the monthly incidence data of smear-positive tuberculosis(2005-2009),and the model was used to forecast the monthly incidence of Jan.2010to Dec.2010.The short-term forecasting efficacy was evaluated.Results The established ARIMA(1,1,0)×(0,1,1)12model was suitable for forecasting the monthly incidence of smear-positive tuberculosis in Chongqing.The observed values of 2005-2009were in the 95%confidence interval of the fitted values,and the average relative error of the predictive value was 6.31%for 2010.Conclusion ARIMA(1,1,0)×(0,1,1)12model can satisfactorily forecast the monthly incidence of smear-positive tuberculosis in Chongqing,which provides a reliable evidence for control and prevention of tuberculosis.

Incidence of smear-positive tuberculosis in Dabat, northern Ethiopia

To determine the incidence of smear-positive tuberculosis (TB) in Dabat District, northern Ethiopia. Using a population-based longitudinal design, a TB surveillance system was initiated among 46,165 residents at the Dabat Health and Demographic Surveillance System site. Trained field workers visited each household every third month and interviewed all individuals aged ≥14 years using a uniform questionnaire to detect suspected cases of TB (cough ≥15 days), at which time two sputum (spot-morning) samples were collected for smear microscopy. A total of 281,820 person-months were observed during the 1-year period, which generated 74 smear-positive TB cases. The incidence of smear-positive TB was calculated at 311 per 100,000 person-years (95%CI 240-382). Higher rates were observed among females (incidence rate ratio [IRR] 2.08, 95%CI 1.24-3.52), persons with no schooling (IRR 2.74, 95%CI 1.11-6.78) and urban residents (IRR 2.39, 95%CI 1.39-4.12). The incidence of smear-positive TB is high in Dabat District, suggesting a high risk of transmission in the communities. TB control programmes thus need to improve case-finding mechanisms at the community level in Ethiopia, with greater emphasis on risk groups.

Prevalence of tuberculous infection and incidence of tuberculosis; a re-assessment of the Styblo rule

To evaluate the validity of the fixed mathematical relationship between the annual risk of tuberculous infection (ARTI), the prevalence of smear-positive tuberculosis (TB) and the incidence of smear-positive TB specified as the Styblo rule, which TB control programmes use to estimate the incidence of TB disease at a population level and the case detection rate. Population-based tuberculin surveys and surveys on prevalence of smear-positive TB since 1975 were identified through a literature search. For these surveys, the ratio between the number of tuberculous infections (based on ARTI estimates) and the number of smear-positive TB cases was calculated and compared to the ratio of 8 to 12 tuberculous infections per prevalent smear- positive TB case as part of the Styblo rule. Three countries had national population-based data on both ARTI and prevalence of smear-positive TB for more than one point in time. In China the ratio ranged from 3.4 to 5.8, in the Philippines from 2.6 to 4.4, and in the Republic of Korea, from 3.2 to 4.7. All ratios were markedly lower than the ratio that is part of the Styblo rule. According to recent country data, there are typically fewer than 8 to 12 tuberculous infections per prevalent smear-positive TB case, and it remains unclear whether this ratio varies significantly among countries. The decrease in the ratio compared to the Styblo rule probably relates to improvements in the prompt treatment of TB disease (by national TB programmes). A change in the number of tuberculous infections per prevalent smear-positive TB case in population-based surveys makes the assumed fixed mathematical relationship between ARTI and incidence of smear-positive TB no longer valid.

Estimating the year of eradication of tuberculosis in Japan

The time of eradication of tuberculosis has been discussed for several countries, and based on those results, a new strategic plan and goals have been elaborated. Considering such developments, and in order to make a new tuberculosis control strategy, it is important to determine the point at which eradication of tuberculosis would be achieved in Japan. Styblo proposed the two conventional definitions of eradication of tuberculosis, namely that the incidence of smear-positive tuberculosis has fallen below 1 per million population or that the prevalence of tuberculosis infection in the general population has fallen below 1% and continues to decrease. The bacteriological results of new cases have been reported since 1975 in Japan. However, those results are still of doubtful validity and reliability. Therefore, the author estimated the year of eradication of tuberculosis, according to the criterion that tuberculosis is eradicated when the proportion of the population infected with tubercle bacilli is less than 1%. If the risk of infection is changing at a regular rate, it is possible to estimate the risk of infection at any time in the past and in the future. Once the risk of infection is determined, it is also possible to calculate the age-specific prevalence of infection and the proportion of the population infected with tubercle bacilli at various times in the past and in the future. In Japan, the risk of infection before World War II was assumed to be around 4% and not to vary with calendar year. And based on the data from the prevalence surveys in Okinawa in 1968 and 1973, the risk of infection was estimated 0.3% in 1968 and has declined on average, by 10 to 11% annually. At that time, Okinawa was the only area free from BCG vaccination in Japan. The incidence rate in Japan also has declined, on average, by 10% annually. However, since late 1970s, the annual speed of decline of the incidence rate has been slowed down. Therefore, I assumed that the recent trend of the infection risk is the same as the trend of the recent incidence rate among the 0-29 year age-group. The size of the effect of age on the risk of infection has been discussed. The author also considered age-effects in the model. The weight applied to the risk of infection by age was determined by examining the age-specific positive rate in the 1930s before the era when BCG vaccination was widely used.(ABSTRACT TRUNCATED AT 400 WORDS)