Asymptomatic Tuberculosis Research Articles

Maligniteyi taklit eden asemptomatik bir tüberküloz olgusu

Tuberculosis is one of the most important public health problems. It is most commonly seen in the lungs. It is easy to diagnose pulmonary tuberculosis with typical clinical and radiological findings. In addition to the appearance of pneumonia and atelectasis, it may mimic bronchial asthma and malignancy more rarely. We present a case of asymptomatic tuberculosis mimicking malignancy radiologically.

Screening for Tuberculosis Infection among Asymptomatic Students of a Nigerian Tertiary Institution: Comparing Three Different Methods

Background: Tuberculosis (TB) screening is not common among asymptomatic individuals despite its global health threat. Exposure of undergraduate medical and allied students to infections, for example TB, during clinical postings and their living conditions underscores the reason for investigating these asymptomatic students living in the hostel of a tertiary institution in a resource poor setting. Further, Interferon Gamma Release Assay (IGRA) is adjudged the best method for screening Latent Tuberculosis Infection (LTBI) but due to its cost, the use of Enzyme Linked Immunosorbent Assay (ELISA) was explored in this study. Objective: To explore and compare the use of tuberculin skin test (TST), chromatographic rapid blood test and TB ELISA screening technique for detection of TB infection among asymptomatic students in a medical hostel. Method: One hundred and twenty apparently healthy medical and allied students of the College of Medicine of the University of Lagos, Lagos, Nigeria, were enrolled in this study. Questionnaires were administered to consented participants and TB detection was performed using TST, ELISA and chromatographic rapid blood test methods. Results: The prevalence of asymptomatic TB using ELISA was 36.7% and 29.2% for TST. These results showed agreement when tested statistically (X 2 = 1.646; P = 0.199; concordance agreement of 65.8%; 95% CI) while no TB was detected using the chromatographic rapid blood test kit. The positive and negative predictive values of ELISA were 66.7% and 100% respectively. When tested statistically, there was correlation between TB detection and contact with persons having active TB. Conclusion: It could be suggested that ELISA and TST method can be used for TB detection among asymptomatic individuals in a resource poor setting where IGRA may be expensive and uncommon.

Diagnostic Value of Symptom Screening for Pulmonary Tuberculosis in China

ObjectiveTo evaluate the diagnostic value of symptom screening for tuberculosis (TB) case finding defined in National Tuberculosis Control Program in China (China NTP) among elderly people(≥65 years) and younger people(<65 years).MethodsWe made a secondary analysis in a population-based TB prevalence survey in China in 2010. Questionnaire including information for cough and haemoptysis was completed by face to face interview, and then chest radiography was conducted in all eligible participants. Sputum smear and culture were followed for all TB suspects. We calculated the odds ratios (OR), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the area under the receiver operating characteristic curve (AUC) of using different symptoms for screening to detect bacteriologically positive TB in subpopulations stratified by age 65, to evaluate the performance of symptom screening for TB.FindingsOf 315 newly diagnosed bacteriologically positive TB, 131 patients (41.59%) were elderly, and 48.57% of TB patients were asymptomatic. Nearly 50% patients did not present cough of any duration, and less than half present cough more than 2 weeks, a defined suspected symptom in China NTP. Cough of any duration was reported more in patients aged under 65 than those in elderly, especially for the acute cough (9.78% vs 6.87%). Those symptoms defined by China NTP were reported by less than half participants in two subpopulations. Acute cough (<2 weeks) was an independent predictor of TB in people aged under 65 (adjusted OR: 3.3, 95% CI: 2.0-5.5), but not in those aged 65 and above (adjusted OR: 1.4, 95% CI: 0.7-2.9). The specificity for each symptom was significantly higher in participants aged under 65 (P<0.01), and sensitivities of most symptoms were significantly higher among elderly (P<0.05 or P<0.01). When compared with cough for 2 weeks and more, using cough of any duration for symptom screening increased the sensitivity from 42.9% to 51. % for all participants, and the AUC increased from 0.70 to 0.74 for participants aged under 65 without significant difference.ConclusionsThere is a high percent of asymptomatic TB patients, and those symptoms adopted in China NTP for screening is poorly predictive for TB. The presence of TB symptoms, the sensitivities and specificities of symptoms for TB were distinct between two subpopulations cut by age 65, implying different case finding strategies should be established for them. The current case finding strategy should be improved, and further studies should be done to evaluate the performance and cost-effectiveness of different symptom screening strategy.

Burden of tuberculosis at post mortem in inpatients at a tertiary referral centre in sub-Saharan Africa: a prospective descriptive autopsy study

Patients with subclinical tuberculosis, smear-negative tuberculosis, extrapulmonary tuberculosis, multidrug-resistant tuberculosis, and asymptomatic tuberculosis are difficult to diagnose and may be missed at all points of health care. We did an autopsy study to ascertain the burden of tuberculosis at post mortem in medical inpatients at a tertiary care hospital in Lusaka, Zambia. Between April 5, 2012, and May 22, 2013, we did whole-body autopsies on inpatients aged at least 16 years who died in the adult inpatient wards at University Teaching Hospital, Lusaka, Zambia. We did gross pathological and histopathological analysis and processed lung tissues from patients with tuberculosis through the GeneXpert MTB/RIF assay to identify patients with multidrug-resistant tuberculosis. The primary outcome measure was specific disease or diseases stratified by HIV status. Secondary outcomes were missed tuberculosis, multidrug-resistant tuberculosis, and comorbidities with tuberculosis. Data were analysed using Pearson χ(2), the Mann-Whitney U test, and binary logistic regression. The median age of the 125 included patients was 35 years (IQR 29-43), 80 (64%) were men, and 101 (81%) were HIV positive. 78 (62%) patients had tuberculosis, of whom 66 (85%) were infected with HIV. 35 (45%) of these 78 patients had extrapulmonary tuberculosis. The risk of extrapulmonary tuberculosis was higher among HIV-infected patients than among uninfected patients (adjusted odds ratio 5·14, 95% CI 1·04-24·5; p=0·045). 20 (26%) of 78 patients with tuberculosis were not diagnosed during their life and 13 (17%) had undiagnosed multidrug-resistant tuberculosis. Common comorbidities with tuberculosis were pyogenic pneumonia in 26 patients (33%) and anaemia in 15 (19%). Increased clinical awareness and more proactive screening for tuberculosis and multidrug-resistant tuberculosis in inpatient settings is needed. Further autopsy studies are needed to ascertain the generalisability of the findings. UBS Optimus Foundation, EuropeAID, and European Developing Countries Clinical Trials Partnership (EDCTP).

Asymptomatic Colonic Tuberculosis in an Immunocompetent Patient

We present a case of a woman found to have features concerning for tuberculosis on a screening colonoscopy. Colonic tuberculosis presents with diverse clinical manifestations and resembles other clinical disorders, making its diagnosis challenging. It is imperative to know the classic risk factors and features that define this disease, as empiric treatment is often needed.

Asymptomatic Colonic Tuberculosis

Asymptomatic Colonic Tuberculosis

Mycobacterium tuberculosis Infection Interferes with HIV Vaccination in Mice

Tuberculosis (TB) has emerged as the most prominent bacterial disease found in human immunodeficiency virus (HIV)-positive individuals worldwide. Due to high prevalence of asymptomatic Mycobacterium tuberculosis (Mtb) infections, the future HIV vaccine in areas highly endemic for TB will often be administrated to individuals with an ongoing Mtb infection. The impact of concurrent Mtb infection on the immunogenicity of a HIV vaccine candidate, MultiHIV DNA/protein, was investigated in mice. We found that, depending on the vaccination route, mice infected with Mtb before the administration of the HIV vaccine showed impairment in both the magnitude and the quality of antibody and T cell responses to the vaccine components p24Gag and gp160Env. Mice infected with Mtb prior to intranasal HIV vaccination exhibited reduced p24Gag-specific serum IgG and IgA, and suppressed gp160Env-specific serum IgG as compared to respective titers in uninfected HIV-vaccinated controls. Importantly, in Mtb-infected mice that were HIV-vaccinated by the intramuscular route the virus neutralizing activity in serum was significantly decreased, relative to uninfected counterparts. In addition mice concurrently infected with Mtb had fewer p24Gag-specific IFN-γ-expressing T cells and multifunctional T cells in their spleens. These results suggest that Mtb infection might interfere with the outcome of prospective HIV vaccination in humans.

Latent and subclinical tuberculosis in HIV infected patients: a cross-sectional study

BackgroundHIV and tuberculosis (TB) are commonly associated. Identifying latent and asymptomatic tuberculosis infection in HIV-positive patients is important in preventing death and morbidity associated with active TB.MethodsCross-sectional study of one time use of an interferon-gamma release assay (T-SPOT.TB - immunospot) to detect tuberculosis infection in patients in a UK inner city HIV clinic with a large sub-Saharan population.Results542 patient samples from 520 patients who disclosed their symptoms of TB were tested. Median follow-up was 35 months (range 27-69). More than half (55%) originated from countries with medium or high tuberculosis burden and 57% were women. Antiretroviral therapy was used by 67%; median CD4 count at test was 458 cells/μl. A negative test was found in 452 samples and an indeterminate results in 40 (7.4%) but neither were associated with a low CD4 count. A positive test was found in 10% (50/502) individuals. All patients with positive tests were referred to the TB specialist, 47 (94%) had a chest radiograph and 46 (92%) attended the TB clinic. Two had culture-positive TB and a third individual with features of active TB was treated. 40 started and 38 completed preventive treatment. One patient who completed preventive treatment with isoniazid monotherapy subsequently developed isoniazid-resistant pulmonary tuberculosis. No patient with a negative test has developed TB.ConclusionsWe found an overall prevalence of latent TB infection of 10% through screening for TB in those with HIV infection and without symptoms, and a further 1% with active disease, a yield greater than typically found in contact tracing. Acceptability of preventive treatment was high with 85% of those with latent TB infection eventually completing their TB chemotherapy regimens. IGRA-based TB screening among HIV-infected individuals was feasible in the clinical setting and assisted with appropriate management (including preventive treatment and therapy for active disease). Follow-up of TB incidence in this group is needed to assess the long-term effects of preventive treatment.

Reactivation of latent tuberculosis in rhesus macaques by coinfection with simian immunodeficiency virus

Tuberculosis (TB) and AIDS together present a devastating public health challenge. Over 3 million deaths every year are attributed to these twin epidemics. Annually, ∼11 million people are coinfected with HIV and Mycobacterium tuberculosis (Mtb). AIDS is thought to alter the spontaneous rate of latent TB reactivation. Macaques are excellent models of both TB and AIDS. Therefore, it is conceivable that they can also be used to model coinfection. Using clinical, pathological, and microbiological data, we addressed whether latent TB infection in rhesus macaques can be reactivated by infection with simian immunodeficiency virus (SIV). A low-dose aerosol infection of rhesus macaques with Mtb caused latent, asymptomatic TB infection. Infection of macaques exhibiting latent TB with a rhesus-specific strain of SIV significantly reactivated TB. Rhesus macaques are excellent model of TB/AIDS coinfection and can be used to study the phenomena of TB latency and reactivation.

High prevalence of subclinical tuberculosis in HIV-1-infected persons without advanced immunodeficiency: implications for TB screening

BackgroundThe prevalence of asymptomatic tuberculosis (TB) in recently diagnosed HIV-1-infected persons attending pre-antiretroviral therapy (ART) clinics is not well described. In addition, it is unclear if the detection of Mycobacterium...

A Tapping the usefulness of Whole Blood Interferon-γ Assay for Diagnosing Tuberculosis Infection in Children

Background: QuantiFERON(R)-TB Gold In Tube (QFT-G IT) has been used for diagnosing Latent tuberculosis infection and active tuberculosis (TB) since 2007. However, there has not been enough data on QFT-G IT for universal use in children. In this study, we evaluated the clinical usefulness of the QFT-G IT in pediatric practice. Methods: We retrospectively reviewed the clinical records of 70 patients younger than 18 years of age who had taken QFT-G IT and had a tuberculin skin test (TST) between July 2007 and July 2009 at Wonju Christian Hospital. The subjects were divided into two groups, asymptomatic TB exposure group and disease group. Four patients who were taking immunosuppressants during the study period were excluded. Results: A total of 66 immunocompetent children were included in this study. Among 27 asymptomatic children who had contact histories of TB, 6 (22.2%) were found to be positive by QFT-G IT. Eleven (40.7%) and 5 (18.5%) children were found to be positive by TST with cutoff values of ≥5 mm and ≥10 mm, respectively. Agreement was fair to good between QFT-G IT and TST (κ=0.59: cutoff value ≥5 mm, κ=0.7: cutoff value ≥10 mm). In disease group, 14 patients (35.9%) were diagnosed with active tuberculosis, 8/14 (57.1%) were positive on TST and 9/14 (64.3%) on QFT-G IT. The positive rate of acid-fast bacilli smear, TB-polymerase chain reaction, and culture for tuberculosis was 11% (1/9), 27.3% (3/11) and 33.3% (3/9), respectively. Conclusion: Our data support that the QFT-G IT can be used as an additional diagnostic tool for Latent and active tuberculosis infection in children.

Initial results of QuantiFERON-TB Gold testing in patients with uveitis

To describe the use of the second-generation QuantiFERON-TB Gold (QFT-G) test in a series of patients in an ophthalmic practice. The charts of all patients who had QFT-G tests ordered by Mayo Clinic ophthalmologists in the past 3 years were reviewed. A total of 27 QFT-G tests were ordered. Thirteen (48%) tests were negative, six (22%) were indeterminate, two (7%) tests were re-ordered after a lab accident or an improper cancellation, four (15%) were positive and represented infection, and two (7%) were positive but negative when re-tested. Of the four truly positive cases, three were treated for tuberculosis (TB): one had tuberculous iritis, one had retinal vasculitis and haemorrhage, and one had asymptomatic TB but was on immunosuppressive therapy. The fourth patient had previously been treated for latent infection. In a series of selected patients with uveitis, the QFT-G test was able to detect TB infection in 15% of the patients, though it does not differentiate between active and latent TB infection. QFT-G should be considered in place of purified protein derivative testing in those with uveitis that have had prior BCG vaccination and in immunocompromised patients. Patients with a positive QFT-G, but who have little risk for TB infection and a negative systemic work-up, should be re-tested.

Chronic eosinophilic pneumonia in a 13-year-old child

We report a case of a 13-year-old girl with an asymptomatic isoniazid-resistant tuberculosis contact. Six months after the contact had been made, chest radiography showed left upper lobe infiltrates without hilar lymphadenopathy, which led to the start of an antituberculous treatment. Tuberculin skin test remained negative and blood tests showed hypereosinophilia. One month after the onset of the treatment, she presented with asthenia, weight loss, and cough. She was admitted to our unit with a diagnosis of drug-resistant tuberculosis. Blood tests showed the persistence of hypereosinophilia. Chest radiograph and high-resolution lung computed tomography (CT) scan showed alveolar peripheral condensations on both upper lobes without significant hilar lymphadenopathy. Bronchoalveolar lavage (BAL) showed a normal total cell count with 44% of eosinophils. Microbiological analyses were all negative. Chronic eosinophilic pneumonia (CEP) was confirmed after the elimination of other different eosinophilic lung diseases. The patient was highly responsive to high doses of oral corticosteroids. Dyspnoea and cough disappeared within one week and chest CT scan showed regression of the lung infiltrates within one month. No relapse occurred during the following nine months.

Tuberculosis in Healthcare Workers at a General Hospital in Mexico

To determine the incidence rate of tuberculosis (TB) disease among healthcare workers (HCWs) at a general hospital. Retrospective analysis of TB cases among HCWs over the course of 5 years. A 140-bed general hospital in Tijuana, Mexico. All hospital employees who developed TB during the 5-year period. From 1 January 1999 through 31 December 2003, 18 TB cases were diagnosed among the hospital personnel. During that period, the mean (+/- standard deviation) annual work force of the hospital was 819+/-21.7 employees. The TB incidence rate was 439.56 cases per 100,000 employees; this rate was 10.98 times higher than the rate for the general population of the city. The TB incidence rate for physicians was 860.21 cases per 100,000 employees, that for nurses was 365.85 cases per 100,000 employees, and that for physicians in training was 1,846.15 cases per 100,000 employees. Physicians in training had a higher risk of acquiring TB than did either physicians (relative risk, 2.14 [95% confidence interval, 1.34-35.66) or nurses (relative risk, 5.04 [95% confidence interval, 3.16-83.33). Three of the HCWs with TB disease were infected with a drug-resistant strain of Mycobacterium tuberculosis, and one of the infecting strains was multidrug resistant. Asymptomatic TB infection among HCWs was not addressed during this study. The TB incidence rate among the HCWs at the hospital is extremely high, compared with that in the general population. The implementation of infection control measures is an urgent priority, to reduce this occupational hazard.

Evidence for a rhesus monkey model of asymptomatic tuberculosis

Rhesus monkeys (RM) were inoculated intrabronchially with graded doses of Mycobacterium tuberculosis (MTB) strains Erdman and H37Rv in an effort to produce a model of asymptomatic tuberculosis infection. Erdman strain produced active disease within 7-11 weeks regardless of dose. Low doses of H37Rv resulted in asymptomatic infections; high doses produced active disease within 11 weeks. Over a 4-month period of post-inoculation study, MTB culture-filtrate protein (CFP)-stimulated bronchoalveolar lavage cells (BALC) and blood mononuclear cells (PBMC) from monkeys with active disease (30 cfu Erdman-inoculated) or asymptomatic infection (200 cfu H37Rv-inoculated) produced similar significant quantities of mRNA encoding for IFN-gamma or TNF-alpha, but insignificant quantities of IL-4 mRNA. Differences were observed in antigen-induced in vitro blastogenic responses and serum anti-lipoarabinomannan (LAM) antibody responses in animals with active compared with asymptomatic MTB infections. The results indicate that RM are a good model for the study of asymptomatic tuberculosis infections using low doses of H37Rv.

Is there a role for chest radiography in identification of asymptomatic tuberculosis in HIV-infected people?

Is there a role for chest radiography in identification of asymptomatic tuberculosis in HIV-infected people?

Chest radiographs of asymptomatic tuberculosis skin test positive patients

Chest radiographs of asymptomatic tuberculosis skin test positive patients

TB in Migrant Farmworkers

To the Editor. —The Office of Migrant Health, Department of Health and Human Services, estimates there to be more than 4 million migrant and seasonal farmworkers in the United States. Among other health problems, these workers suffer a significantly higher rate of tuberculosis (TB) infection compared with the general population. This also includes a high rate of asymptomatic TB, found to be 33% in Hispanic migrant workers in one typical study. 1 With a lifetime risk of 10% for developing active TB, it is understandable that this high-risk population constitutes one of the top priorities of the Advisory Council for Elimination of Tuberculosis, Department of Health and Human Services. In attempting to comply with Centers for Disease Control and Prevention recommendations for TB screening, 2 our mobile migrant worker clinic in north central Ohio offered Mantoux tuberculin skin testing to farmworkers and their families from June through September 1993. Approximately

Effective Dose Equivalent and Associated Risks from Mass Chest Radiography in Kuwait

The number of x-ray examinations performed on persons undergoing mass chest radiography in Kuwait reached a maximum of 1.858 X 10(5) in 1982 with miniature radiography (70 mm) claiming more than 90% of the total number and the rest done with the large film technique. The annual prevalence of asymptomatic tuberculosis patients diagnosed by x rays, as reported by the project statistics, does not, in our opinion, justify exposing such a large population. In this paper, the effective dose equivalent is calculated from both miniature and large film mass chest radiography as applied in Kuwait. The values obtained are 283 mu Sv and 35.5 mu Sv, respectively. These figures yield calculated risks of fatal malignancies per examination of 3.37 X 10(-6) and 0.422 X 10(-6), respectively. The annual collective effective dose equivalent to the population undergoing mass chest radiography in Kuwait during the 7 y 1977-1983 is found to vary between 38-48 man-Sv. These figures are used to calculate an average of 0.5 additional cases of fatal malignancies per year, or about 12 excess fatalities in the forthcoming 25-y period if the number of mass chest x-ray examinations stays at its existing level. A total of 98% of these calculated excess fatalities result from the predominant technique, miniature radiography.

Diagnosis and neurosurgical treatment of tuberculous disease of the CNS.

The tuberculoma is a space-occupying lesion encountered frequently by all Indian Neurosurgeons. Some features indicate the possibility of such a lesion. These are: tuberculous disease in the past or contact with a tuberculous patient, a positive Mantoux test, pyrexial onset of the disease and frequent history of seizures. The radiological features are not diagnostic, but the presence of multiple, enhancing lesions on the CT scan in a young patient, strongly suggest tuberculomas. Surgical excision of the lesion is recommended, partial near vital areas, and sometimes, with tuberculomas in areas like the thalamus and brain stem only medical therapy is advisable. Long-term medical treatment is necessary. Towards eradication of the disease all those close to the patient need to be examined for early detection of asymptomatic tuberculosis.