Risk factors of tuberculosis pdf

For persons whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for persons with normal immune systems.

Babies and young children often have weak immune systems. Other people can have weak immune systems, too, especially people with any of these conditions:.

Skip directly to site content Skip directly to page options Skip directly to A-Z link. Tuberculosis TB. Section Navigation. Smoking results in histological changes in the lower respiratory tract, including peri-bronchial inflammation, fibrosis, vascular intimal thickening, and destruction of alveoli. This leads to alterations in the epithelial function, such as reduced ciliary activity, decreased clearance of inhaled substances, and abnormal vascular and epithelial permeability, and in effect increasing the risk of developing pulmonary diseases such as TB.

However the prevalence of smoking in this study is so low to explain any possible association. This has be documented in other studies, where absence of BCG vaccination, as significant risk factors for LTBI [ 46 ] and that could facilitate disease transmission [ 47 ].

We acknowledge possibilities for residual confounders in this study. Those with high household income are likely to live in houses with multiple windows, better awareness about prevention and control, better access to health service, BCG vaccination, etc.

A big scale researches with adequate sample size and sufficient representation of the diverse variables can help to filter out the relative effect of each factor. This case control study explored different socio-demographic factors and demonstrated some of the factors contributing to occurrence of TB disease.

It showed that TB is more common among the most agile and economically active age group, males, low income segment of the society, overcrowded and poor standard of living.

Several other factors were also studied including risk associated with having a household members who had TB, smoking cigarettes, history of visiting a health facility, etc. In the final analysis the study identified seven key factors as standout risk factors for tuberculosis in this setting which are illiteracy, low household income, living in house without or single window, household member with TB and previous history of hospital admission.

BCG scar was found to be protective factor. Therefore it is imperative that the TB control effort need a strategy to address broader socio economic issues such as poverty, overcrowding, smoking as elements of the national response to control TB.

Infection control at health care facilities level is an important intervention to prevent transmission of TB within the facilities in order to protect visitors, patients as well as health care providers, and need to be implemented across the health system from health posts to hospitals.

The authors wish to thank the research participants for their cooperation and willingness to participate in the study. We thank the research team members for their hard work and amazing support throughout the process. We appreciate staff and management of the twenty study health centers and AHRI for their support in data collection and data management. The valuable contributions of professors at school of public health and experts at AHRI in overall assistance and technical support are highly acknowledged.

We thank Addis Ababa health bureau and regional laboratory and research unit for their cooperation. Browse Subject Areas?

Click through the PLOS taxonomy to find articles in your field. Abstract Background Tuberculosis remains a major public-health problem in the world, despite several efforts to improve case identification and treatment compliance.

Objectives and methods A case control study was carried out to assess the risk factors of TB, where cases were newly registered bacteriologically confirmed pulmonary TB patients with age greater than 15 years who present at twenty health centres in Addis Ababa. Results A total of cases and controls were enrolled in the study and Conclusion This study showed that TB is more common among the most agile and economically active age group, and number of windows, history of hospital admission, a household member who had TB, illiteracy, low household income and smoking and lack of BCG scar were identified as independent risk factors.

Introduction Tuberculosis TB remains a major public-health problem in the world, despite several efforts to improve case identification and treatment compliance. Materials and methods Study population A case control study was carried out to assess the risk factors of TB and cases were newly registered bacteriologically confirmed pulmonary TB patients with age greater than 15 years who present at twenty health centres in Addis Ababa that are selected for the study in consultation with Addis Ababa Health Bureau, while controls were age and sex matched attendees who presented in the same health centers for non-TB health problems.

Sample size The sample size determined for the study was calculated using the formula when the interest is to test a hypothesis comparing some exposure of two groups, seen in Box 1. Box 1. Sample size calculation for the study.

The data collection has taken place by including all newly registered TB patients until the required sample size was reached. Selection of health facility control ; OPD attendee in the same facility with age within 5 year age bands and sex-matched with a respective case were selected as control. Attendees fitting the age and sex criteria were approached on a clinic day. The controls were seen by the study doctor to manage their medical complaint and to have a clinical screening to exclude pulmonary TB.

If the client had any sign suggestive of TB, the necessary laboratory tests for TB were ordered according to the national diagnostic algorithm. Since AFB microscopy tests is provided free of charge, there was no cost incurred.

However if there is a need for other investigations like X-ray, the cost was covered by the study. Box 2. Inclusion and exclusion criteria for the study. Inclusion criteria Cases; Bacteriologically confirmed pulmonary TB patients enrolled for treatment in selected health centres in Addis Ababa.

Age more than 15 years Controls; Attendees of health facility for non-TB health problems Age more than 15 years Sex and age matched with case within 5 year age bands. Exclusion criteria Smear negatives TB, relapse, Treatment failure, Treatment after lost to follow up. All health facility controls with clinical sign or symptom suggestive of TB. Data analysis The data captured in the questionnaires was grouped and examined for errors, then cleaned, and entered into RedCap version 8.

Ethical considerations The research proposal was subjected to screening for scientific and ethical integrity by Ethical review committee at School of Public Health, and institutional review board of the College of Health Sciences, Addis Ababa University.

Time frame The study commenced in January and the data was collected in the period till 30 December Results Socio- demographic characteristics of the participants A total of cases and controls participated in the study.

Download: PPT. Table 1. Living conditions The median family size was 3 for cases and 4 for controls, and more than half Table 2. Life style As seen in Table 3 , some Table 3. Previous medical history Table 4 shows that about a quarter of the cases Table 4.

Knowledge about tuberculosis As seen in Table 5 , majority of cases Table 5. Comparative analysis The bivariate analysis revealed a crude association with developing TB, for illiterate, household size of less than 4 people, household income less than birrs, those living in single room house, with no or one window, smoking, BCG scar and history of hospital admission.

Table 6. The overall predictors of developing TB All variables which had shown statistically significant association during the bivariate analysis, were collectively entered in the multivariable analysis, and according to the multivariable logistic regression analysis, seven variables were found to be independent predictors for the occurrence of TB after controlling possible confounders. Table 7. Discussion A total of patients participated in this case control study which was carried out in Addis Ababa, Ethiopia, which include bacteriologically confirmed pulmonary TB patients and clinic attendees.

Conclusion This case control study explored different socio-demographic factors and demonstrated some of the factors contributing to occurrence of TB disease.

Supporting information. S1 File. S2 File. References 1. Osterberg L. Adherence to Medication: A Review. New England Journal of Medicine , — The Global plan to stop TB — Investigation of the risk factors for tuberculosis: a case—control study in three countries in West Africa. Int J Epidemiol. Risk factors for tuberculosis infection in Sub-Saharan Africa. The bacteria can remain suspended in the air for hours, potentially infecting anyone who breathes them in.

When a patient who has never been exposed to TB inhales the bacteria, it results in an initial TB infection, or primary infection. At this stage, some people have no symptoms, while others may experience fever or pulmonary symptoms.

Or the bacteria may then remain in a latent, or dormant, state — it's in your system, but not making you sick. But in some cases, the bacteria eventually reactivate and multiply, leading to the active form of TB — when it makes the person symptomatic and contagious.

Jani, MD , a hospital epidemiologist based in Orlando, Florida. Risk factors for tuberculosis include anything that weakens a person's immune system or puts someone in frequent, close contact with a person who has active TB. Certain populations are at a higher risk because their immune systems are weaker. Areas of the world with higher rates of tuberculosis include: 1, 7.

Some of the main risk factors for tuberculosis include: 1,4,5,6, 8. In general, the best way to prevent tuberculosis is to keep your immune system healthy and avoid getting exposed to someone with active TB.

Throughout history, general improvements in health and hygiene have shown drastic reductions in TB cases, says Hayan Yacoub, MD , internal medicine practitioner at Austin Regional Clinic in Texas. Yacoub has treated people with latent TB at his practice. As a safeguard against TB, he recommends eating healthy and exercising to keep your immune system strong. Another big part of preventing new tuberculosis cases is identifying and treating people with latent TB before the disease can become active, especially in high-risk populations.

If latent TB is treated properly, the bacteria can be killed before it multiplies, making the person sick and infectious.

Some residential institutions, such as nursing homes, also screen all new residents for tuberculosis. Screening for active TB is best accomplished by a chest X-ray.