Comparison of different diagnostic modalities for isolation of Mycobacterium Tuberculosis among suspected tuberculous lymphadenitis patients

Tuberculosis is a communicable disease with high morbidity and mortality rates in developing countries. The study's primary objective is to compare conventional methods such as acid-fast bacillus (AFB) culture and microscopy with rapid diagnostic methods. The secondary objective is to compare histopathological and microbiological findings in suspected patients with tubercular lymphadenitis. A total of 111 samples (August 2018 to September 2019) of lymph nodes were processed for AFB microscopy, AFB cultures, drug-susceptibility testing (DST), histopathology, and Xpert Mycobacterium Tuberculosis (MTB)/resistance to Rifampin (RIF) assays. Out of 111 lymph node samples, 6 (5.4%) were positive for AFB smear microscopy, 84 (75.6%) were positive for AFB culture, 80 (70.7%) were positive on Gene Xpert, and 102 (91.8%) were indicative of tuberculosis for histopathology studies. Mycobacteria growth indicator tube (MGIT) culture positivity was 84 (75.6%) higher than solid Lowenstein-Jensen (LJ) culture 74 (66.6%). Positive cultures underwent phenotypic DST. Two cases were Multidrug-resistant (MDR) on DST, while three cases were Rifampicin resistant on Gene Xpert. The sensitivity of Genexpert was (62%) against the conventional AFB culture method. The poor performance of conventional lymphadenitis diagnostic methods requires early and accurate diagnostic methodology. Xpert MTB/RIF test can help in the treatment of multidrug-resistant TB cases. Nonetheless, rapid and conventional methods should be used for complete isolation of Mycobacterium tuberculosis.

Tween 80 Improves the Acid-Fast Bacilli Quantification in the Magnetic Nanoparticle-Based Colorimetric Biosensing Assay (NCBA)

Despite its reduced sensitivity, sputum smear microscopy (SSM) remains the main diagnostic test for detecting tuberculosis in many parts of the world. A new diagnostic technique, the magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was optimized by evaluating different concentrations of glycan-functionalized magnetic nanoparticles (GMNP) and Tween 80 to improve the acid-fast bacilli (AFB) count. Comparative analysis was performed on 225 sputum smears: 30 with SSM, 107 with NCBA at different GMNP concentrations, and 88 with NCBA-Tween 80 at various concentrations and incubation times. AFB quantification was performed by adding the total number of AFB in all fields per smear and classified according to standard guidelines (scanty, 1+, 2+ and 3+). Smears by NCBA with low GMNP concentrations (≤1.5 mg/mL) showed higher AFB quantification compared to SSM. Cell enrichment of sputum samples by combining NCBA-GMNP, incubated with Tween 80 (5%) for three minutes, improved capture efficiency and increased AFB detection up to 445% over SSM. NCBA with Tween 80 offers the opportunity to improve TB diagnostics, mainly in paucibacillary cases. As this method provides biosafety with a simple and inexpensive methodology that obtains results in a short time, it might be considered as a point-of-care TB diagnostic method in regions where resources are limited.

TB prevalence in Zimbabwe: a national cross-sectional survey, 2014

BACKGROUND: We conducted the first national TB prevalence survey to provide accurate estimates of bacteriologically confirmed pulmonary TB disease among adults aged ≥15 years in 2014.METHODS: A TB symptoms screen and chest X-ray (CXR) were used to identify presumptive TB cases who submitted two sputum samples for smear microscopy, liquid and solid culture. Bacteriological confirmation included acid-fast bacilli smear positivity confirmed using Xpert® MTB/RIF and/or culture. Prevalence estimates were calculated using random effects logistic regression with multiple imputations and inverse probability weighting.RESULTS: Of 43,478 eligible participants, 33,736 (78%) were screened; of these 5,820 (17%) presumptive cases were identified. There were 107 (1.9%) bacteriologically confirmed TB cases, of which 23 (21%) were smear-positive. The adjusted prevalences of smear-positive and bacteriologically confirmed TB disease were respectively 82/100,000 population (95% CI 47–118/100,000) and 344/100,000 (95% CI 268–420/100,000), with an overall all-ages, all-forms TB prevalence of 275/100,000 population (95% CI 217–334/100,000). TB prevalence was higher in males, and age groups 35–44 and ≥65 years. CXR identified 93/107 (87%) cases vs. 39/107 (36%) using the symptom screen.CONCLUSION: Zimbabwe TB disease prevalence has decreased relative to prior estimates, possibly due to increased antiretroviral therapy coverage and successful national TB control strategies. Continued investments in TB diagnostics for improved case detection are required.

Improved Diagnosis of Pulmonary Tuberculosis using Bleach (Sodium hypochlorite) Concentration Technique at Tertiary Care Hospital

Introduction: In the Revised National Tuberculosis Control Program (RNTCP), microscopic examination of sputum for acid-fast bacilli (AFB) is currently the backbone for the diagnosis of pulmonary tuberculosis. Studies have shown liquefaction and concentration of sputum by 5% sodium hypochlorite is useful in providing increased sensitivity and safety for the handling of specimens. Objective: To assess the utility of the 5% Sodium hypochlorite concentration method in increasing the sensitivity of smear microscopy for detection of AFB for diagnosis of pulmonary tuberculosis. Methods: The study included a total of 1000 sputum samples from 500 patients with suspected pulmonary tuberculosis. Direct smears were prepared from the sputum samples as per RNTCP guidelines. The remaining sputum was used for bleach concentration and smears prepared from the concentrated material. Both smears were stained by Ziehl-Neelsen staining and screened for acid-fast bacilli and graded according to the RNTCP guidelines. Results: A total of 158 samples (15.8%) from 89 patients were positive by a routine direct method whereas by concentration method 236 samples (23.6%) from 143 patients were found positive diagnosing additional 54 patients. The gain in sputum smear positivity of 7.8% over the routine method is highly significant (p=0.0000, χ2= 270) with a 10.8% increase in case detection. Conclusions: Improvement in the sensitivity of smears microscopy will be useful in case detection of tuberculosis especially in resource-poor countries. The increased positivity of microscopy by bleach method indicates that would prove useful if included in the RNTCP to improve case detection. Keywords: Concentration; smear positivity; sodium hypochlorite; tuberculosis.

Diagnostic Features and Mortality of Tuberculosis by TNF-alpha Inhibitor Use in the United States, 2010–2017

Background An elevated risk of tuberculosis disease (TB) in persons who have received tumor necrosis factor-alpha inhibitor medications (TNF-α inhibitors) has been reported for nearly two decades, but clinical diagnostic features and outcomes of TB in this population remain poorly described. Methods We analyzed national surveillance data for TB cases among persons aged 15 years and older reported in the United States during 2010–2017 and associated mortality data reported through 2019 to describe the clinical characteristics of those receiving TNF-α inhibitors. Results Of 70,129 TB cases analyzed, 504 (0.7%) of the patients had TNF-α inhibitor use reported at TB diagnosis. Patients with TNF-α inhibitor use at TB diagnosis were more likely than TB patients not receiving TNF-α inhibitors to have TB diagnosed in extrapulmonary sites in conjunction with pulmonary sites (28.8% vs 10.0%, P<0.001). Patients receiving TNF-α inhibitors were less likely to have acid-fast bacilli (AFB) noted on sputum smear microscopy (25.6% vs 39.1%, P=0.04), and more likely to have drug-resistant disease (13.5% vs 10.0%, P<0.001). TB-attributed deaths did not significantly differ between patients receiving and not receiving TNF-α inhibitors (adjusted odds ratio 1.46, 95% confidence interval 0.95-2.26). Conclusions Clinicians evaluating TNF-α inhibitor-treated patients should have a high index of suspicion for TB and be aware that extrapulmonary or sputum smear negative TB disease is more common in these patients. No significantly diminished survival of TB patients treated with TNF-α inhibitor therapy before TB diagnosis was noted.

Human Papillomavirus Prevalence and Genotype Distribution Landscapes in Shannan City, Tibet Tibetan Autonomous Region, China

Background: Data regarding human papillomavirus (HPV) prevalence and genotype distribution are limited in Shannan City, Tibet Tibetan Autonomous Region, China. The purpose of this study is to provide reliable data for guiding women in Shannan City in cervical cancer screening and HPV vaccine innoculation. Methods: HPV testing was performed on women aged 16 to 109 years (mean age 44.03 ± 9.25 years) from Shannan City in 2019 and 2020, which was implemented technically by gynecological examination, vaginal discharge smear microscopy, cytology, and HPV detection. The overall prevalence, age-specific prevalence, and genotype distribution were analyzed. Results: A total of 48,126 women received HPV testing, of which 3,929 were detected human papillomavirus. The HPV-positive rate was 8.16% (3,929/48,126), and the highest prevalence was in the ≤ 25-year-old age group (12.68%). After the age of 25, the prevalence rate decreased rapidly, and then slowly increased from 7.49% in the 46-55 age group to 9.82% in the ≥ 66 age group, showing a “U-shaped” pattern. The positive prevalence of HPV 16 or 18-only was 1.43%, that of other HPV genotypes except HPV 16 or 18 was 6.39%, and mixed HPV infections including HPV 16 or 18 was 0.34%. Conclusions: The HPV infection rate in Shannan city is rather low, and the age-specific prevalence of HPV infection presents a “U” curve, suggesting the importance of screening among younger women and the necessity of detection among older women.

Triage of Persons With Tuberculosis Symptoms Using Artificial Intelligence–Based Chest Radiograph Interpretation: A Cost-Effectiveness Analysis

Background In settings without access to rapid expert radiographic interpretation, artificial intelligence (AI)–based chest radiograph (CXR) analysis can triage persons presenting with possible tuberculosis (TB) symptoms, to identify those who require additional microbiological testing. However, there is limited evidence of the cost-effectiveness of this technology as a triage tool. Methods A decision analysis model was developed to evaluate the cost-effectiveness of triage strategies with AI-based CXR analysis for patients presenting with symptoms suggestive of pulmonary TB in Karachi, Pakistan. These strategies were compared to the current standard of care using microbiological testing with smear microscopy or GeneXpert, without prior triage. Positive triage CXRs were considered to improve referral success for microbiologic testing, from 91% to 100% for eligible persons. Software diagnostic accuracy was based on a prospective field study in Karachi. Other inputs were obtained from the Pakistan TB Program. The analysis was conducted from the healthcare provider perspective, and costs were expressed in 2020 US dollars. Results Compared to upfront smear microscopy for all persons with presumptive TB, triage strategies with AI-based CXR analysis were projected to lower costs by 19%, from $23233 per 1000 persons, and avert 3%–4% disability-adjusted life-years (DALYs), from 372 DALYs. Compared to upfront GeneXpert, AI-based triage strategies lowered projected costs by 37%, from $34346 and averted 4% additional DALYs, from 369 DALYs. Reinforced follow-up for persons with positive triage CXRs but negative microbiologic tests was particularly cost-effective. Conclusions In lower-resource settings, the addition of AI-based CXR triage before microbiologic testing for persons with possible TB symptoms can reduce costs, avert additional DALYs, and improve TB detection.

Costs of TB services in India (No 1)

BACKGROUND: There is a dearth of economic analysis required to support increased investment in TB in India. This study estimates the costs of TB services from a health systems´ perspective to facilitate the efficient allocation of resources by India´s National Tuberculosis Elimination Programme.METHODS: Data were collected from a multi-stage, stratified random sample of 20 facilities delivering TB services in two purposively selected states in India as per Global Health Cost Consortium standards and using Value TB Data Collection Tool. Unit costs were estimated using the top-down (TD) and bottom-up (BU) methodology and are reported in 2018 US dollars.RESULTS: Cost of delivering 50 types of TB services and four interventions varied according to costing method. Key services included sputum smear microscopy, Xpert® MTB/RIF and X-ray with an average BU costs of respectively US$2.45, US$17.36 and US$2.85. Average BU cost for bacille Calmette-Guérin vaccination, passive case-finding, TB prevention in children under 5 years using isoniazid and first-line drug treatment in new pulmonary and extrapulmonary TB cases was respectively US$0.76, US$1.62, US$2.41, US$103 and US$98.CONCLUSION: The unit cost of TB services and outputs are now available to support investment decisions, as diagnosis algorithms are reviewed and prevention or treatment for TB are expanded or updated in India.

Ten Years of Universal Testing: How the Rapid Diagnostic Test Became a Game Changer for Malaria Case Management and Improved Disease Reporting

In 2010, the World Health Organization changed its guidance on malaria case management, recommending parasitological confirmation of all suspected cases before treatment with an antimalarial. This recommendation was in large part as a result of the availability of quality assured malaria rapid diagnostic tests (RDTs) that made it possible for malaria diagnosis to be performed by laboratory staff in all health facilities irrespective of the facility’s place in the tiered health system. Community health workers and other non-laboratory health workers who traditionally did not perform malaria testing due to the technical and logistic demands of smear microscopy were now able to test for malaria. The use of RDTs has led to substantial increases in testing rates, improved quality of case management, as well as more accurate reporting of malaria cases. Although current RDTs have limitations, they remain one of the most important tools in contemporary malaria control. Further improvements to existing products, such as increased sensitivity for non-falciparum tests, diversification of Plasmodium falciparum antigen targets, along with strengthened health system support for current RDTs will further enhance their utility in malaria control and prevention.

734. Abnormal Lipid Profiles in Human Babesiosis

Background Babesiosis has gained attention as an emerging protozoal zoonotic disease with an expanding known incidence and geographical range in the US. The infection is caused by Babesia microti in the US and is transmitted by the bite of Ixodes ticks, and occasionally by blood transfusion. The diagnosis is usually established by microscopic examination of a stained blood smear to see intraerythrocytic organisms. The level of parasitemia is only loosely correlated with clinical severity. Anecdotal reports suggest that HDL cholesterol levels decline during acute babesiosis. In this study, we report cholesterol levels in a series of patients with acute babesiosis with the hypothesis that HDL levels may be a potential biomarker for more severe infections. Methods A retrospective chart review was performed at Stony Brook University Hospital and Stony Brook Southampton Hospital between 2013 and 2018. Inclusion criteria was defined as a case of acute Babesia infection proven by peripheral blood smear microscopy and who had a lipid profile drawn during presentation to the emergency department. Cholesterol levels that were measured either before or after the infection (at least 1 month apart) were also recorded to compare to the levels reported during acute infection. Results A total of 40 patients (27.5% female) met criteria for acute Babesia infection. Fifteen (37.5%) had a history of splenectomy. The patients were divided into two groups for comparisons based on the treating physician’s clinical decision: 32 patients who were admitted to the hospital and 8 patients who were not-admitted. History of hypertension was more common in admitted than non-admitted patients (37% vs. 17%, Chi-square test p=0.02); the median levels of LDL and HDL were more reduced in admitted than non-admitted patients (46 vs 76 mg/dL, p=0.04 and 9 vs 28.5 mg/dL, p=0.03, based on t-test respectively) Conclusion LDL and HDL levels are significantly reduced in acute babesiosis, and LDL levels are inversely proportional to the parasitemia, suggesting that low levels of LDL may predict worsening disease in babesiosis. The mechanism of this phenomenon is unknown. Further prospective studies are needed. Disclosures All Authors: No reported disclosures