Factors affecting sputum smear conversion time in newly diagnosed pulmonary tuberculosis patients

Background: Patients having tuberculosis are registered in the TB DOTS program for their treatment. During the treatment sputum samples are sent periodically to the laboratory to check treatment efficacy. Usually after two months of treatment sputum smear becomes negative but presence of multiple cavities in the lung, bacillary load, diabetes mellitus and tobacco smoking, slows the sputum smear conversion time

Objectives: To determine the factors affecting sputum smear conversion time in newly diagnosed pulmonary tuberculosis patients

Study design, settings and duration: This cross sectional, analytical study was done by Pakistan Medical Research Council, TB Research Centre in collaboration with Institute of TB and Chest Medicine King Edward Medical University/Mayo Hospital, Lahore from April 2013 to March, 2014

Patients and Methods: All newly diagnosed pulmonary tuberculosis patients who were registered and given treatment by the DOTS program were included in the study. All patients underwent sputum smear microscopy along with Complete Blood Count and ESR at the time of enrollment. The patients were followed for next 6 months while on treatment. Sputum samples were tested at 2[nd] and 6[th] month to check the sputum conversion rate and indirectly to see the efficacy/compliance to treatment

Results: A total of 400 patients were enrolled with slightly more males [52%] as compared to females [48%]. Smear became negative within two months of starting treatment in 85.7% patients while in 14.2% it remained positive at 2[nd] and 6[th] months of therapy. There were more females [10.7%] whose sputum smear did not became negative as compared to males [3.5%]. Predominant factors affecting sputum smear conversion were low resistance, raised initial bacillary load, decreased hemoglobin level, and long duration of symptoms at the time of diagnosis

Conclusion: Factors like low resistance, high initial bacillary load and decreased hemoglobin levels affect the sputum smear conversion and should be addressed while assessing efficacy of anti-tuberculosis treatment

Active case detection among household contacts of multi drug resistant tuberculosis patients in a tertiary care setting

Close contacts of multi drug resistant tuberculosis patients are expected to be at increased risk of developing the disease and therefore need screening on priority basis to have an effective TB control program. Active household contact screening is an effective and cheaper way to detect and treat MDR-TB at its early stages. To determine active TB cases among household contacts of MDR-TB patients in a tertiary care setting. Descriptive study, conducted at PMRC TB Research Centre in collaboration with Institute of Chest Medicine, King Edward Medical University/Mayo Hospital, Lahore from November 2012 to December 2013. Patients suffering from MDR-TB and seeking treatment from Institute of Chest Medicine were selected as index patients. Their contacts [spouses, children, parents, siblings and other relatives] underwent sputum smear microscopy. Those found positive for AFB were subjected for MTB RIF assay by GeneXpert to determine rifampicin resistance. Data was analysed using IBM Statistics SPSS version 20.0. A total of 692 contacts of 112 MDR-TB patients were studied. Among them, 374[54%] were males and 318[46%] female. Seventeen contacts were found smear positive and of these 15[88%] were also confirmed as MTB by GeneXpert. Four [23%] contacts were rifampicin resistant. Of the affected contacts, majority were sisters [23.5%]. Active TB was detected in contacts of patients having MDR-TB with few also showing rifampicin resistance. TB screening should be done in all contacts of TB patients, especially those having drug resistance

Incremental yield of submitting three sputum specimens for the diagnosis of pulmonary tuberculosis

To assess the efficacy and diagnostic yield of third sputum smear among pulmonary TB patients. This retrospective data analysis was done at PMRC TB Research Centre in collaboration with Institute of Chest Medicine, King Edward Medical University/Mayo Hospital Lahore, from January 2010 to December 2011. Patients presenting with respiratory symptoms, having abnormal chest X-rays and having a clinical suspicion of tuberculosis were asked to submit three sputum samples on two consecutive days [1[st]spot, 2[nd]early morning, 3[rd]spot] for acid-fast bacilli smear microscopy. Smears were prepared and stained by Ziehl-Neelsen method. A total of 7785 TB suspects submitted three sputum samples making a total of 23,355 slides for checking acid-fast bacilli using smear microcopy examinations. The smear positivity rate was 11.8%. About 12% suspects fulfilled the case definition of having one positive smear confirmed by a second smear, while, only 2.5% suspects fulfilled the case definition based on third smear in combination with first or second. A total 1164[15%] suspects had at least one positive smear; of these 896[77%] were positive in first smear, 190[16%] were negative in first smear but positive in second and 78[6.7%] were positive in third smear after two negative smears. Recently changed WHO criteria for examination of two sputum smears is based on evidences collected from the globe however, for Pakistan the value of third smear which picked almost 7% cases is quite significant and should still be practiced. Checking AFB using 3 sputum smears should still be practiced in Pakistan especially, for those who are initially negative on 2 smears

Factors responsible for failure to initiate tuberculosis treatment among smear positive tuberculosis patients

Tuberculosis is a major health problem in many parts of the world. Delay in initiation of the treatment may result in prolonged infectious state, drug resistance, relapse and death. To determine the factors responsible for not starting tuberculosis treatment among smear positive tuberculosis patients. Study type, settings and duration: This cross sectional study was done at Pakistan Medical Research Council TB Research Center, King Edward Medical University, Lahore, from 5th March 2010 to 5th December 2010. Patients and Methods: Fifty sputum smear positive patients of tuberculosis who did not register themselves in treatment register and presumably did not initiate anti tuberculosis treatment were contacted using telephone or traced by their home addresses. Once contact was established, they were inquired about the reasons for not starting tuberculosis treatment. Of 50 patients 38[76%] belonged to the lower socio economic class and 12[24%] to the lower middle class. Fourteen patients [28%] were illiterate and 23[46%] had only 8 years of education. Of the 50 cases 41[82%] were taking treatment from traditional healers and 4% did not go back to the DOTS program. Physical condition of the patient, social, domestic and religious issues also played some role in default. Lack of health education and poverty were the main factors responsible for non compliance from treatment. Policy message: Sputum testing sites should have a paramedic who should educate the patients about the benefits of treatment and the dangers of default or partial treatment

Diagnosis of tuberculosis: molecular versus conventional method

Tuberculosis is as old as mankind. One third of the world's population carries the bacillus. Tuberculosis remains the single greatest contributor to the world's morbidity and mortality. Zheil Neelsen stained smears for acid-fast bacilli and culture on Lowenstein Jensen media are the methods being used for the diagnosis of Mycobacterium tuberculosis in most developing countries. Zheil Neelsen smear is rapid but less sensitive and culture is more sensitive and specific but results in delay in definitive diagnosis. Polymerase chain reaction test for the diagnosis of tuberculosis is not well evaluated in developing countries. To compare the ability of polymerase chain reaction to diagnose Mycobacterium tuberculosis rapidly in pulmonary and extra-pulmonary clinical specimens, and compare it with the yield of smear positivity and culture. This was a comparative study which was carried out at PMRC TB Research Center, King Edward Medical University, Mayo Hospital Lahore in collaboration with Shaukat Khanum Memorial Cancer Hospital from November 2008 to October 2009. Clinically suspected cases of pulmonary and extra-pulmonary patients with symptoms of fever, fatigue, anorexia and weight loss were asked to submit their sputum or respective samples for the diagnosis of tuberculosis. Direct and concentrated smears were prepared and stained by Zheil Neelsen method and were subjected to culture on Lowenstein Jensen media. Decontaminated specimens were checked for mycobacteria using polymerase chain reaction where amplicons were used for detection to membrane bound probes on the strips. A total of 98 specimens were processed for acid-fast bacilli smear, culture and polymerase chain reaction. These included 67 specimens from cases having strong clinical suspicion of tuberculosis while, 31 sputum specimens from non-tuberculosis subjects served as negative controls. Over all polymerase chain reaction positivity was 62.2%, culture positivity was 52% and smear positivity was 35.7%. Polymerase chain reaction testing was the most specific, rapid and sensitive method for the diagnosis of tuberculosis while culture is specific but it takes 4 to 6 weeks to provide results and smear testing is the cheapest but least sensitive test. Early diagnosis of TB is cornerstone for proper treatment and control of this deadly disease. PCR testing is specific, rapid and sensitive method for diagnosis of TB especially in complicated cases