COVID-19 infection and vaccines: potential triggers of Herpesviridae reactivation

Abstract Since the onset of the COVID-19 outbreak, numerous articles have highlighted a possible link between COVID-19 vaccination or infection and Herpesviridae co-infection or reactivation. The authors conducted an exhaustive literature review on this topic, the results of which are presented individually for each member of the Herpesviridae family: Herpes Simplex Virus (HSV) types-1 (HSV-1) and 2 (HSV-2); Varicella-Zoster Virus (VZV); Epstein-Barr Virus (EBV); Cytomegalovirus (CMV); HHV-6; HHV-7; and HHV-8. These human herpesviruses can serve as prognostic markers for the COVID-19 infection and may even underlie some of the clinical manifestations initially attributed to SARS-CoV-2. In addition to SARS-CoV-2 infection, all corresponding vaccines approved to date in Europe appear capable of inducing herpesvirus reactivation. It is important to consider all viruses of the Herpesviridae family when managing patients infected with or recently vaccinated against COVID-19.

Tuberculosis preventive treatment in children and adolescents: an observational study of secondary data

Abstract Objective To analyze the effectiveness, safety, outcomes, and associated factors of tuberculosis preventive treatment (TPT) in children and adolescents in Paraná, southern Brazil. Method This was an observational cohort study with a retrospective collection of secondary data from the TPT information systems of the state of Paraná from 2009 to 2016, and tuberculosis in Brazil from 2009 to 2018. Results In total, 1,397 people were included. In 95.4% of the individuals, the indication for TPT was a history of patient-index contact with pulmonary tuberculosis. Isoniazid was used in 99.9% of the cases with TPT, and 87.7% completed the treatment. The TPT protection was 98.7%. Among the 18 people who had TB, 14 (77.8%) became ill after the second year of treatment, and four (22.2%) in the first two years (p < 0.001). Adverse events were reported in 3.3% of cases, most of them were gastrointestinal and medication was discontinued in only 2 (0.1%) patients. No risk factors associated with the illness were observed. Conclusions The authors observed a low rate of illness in pragmatics routine conditions in TPT for children and adolescents, especially within the first two years after the end of treatment, with good tolerability and a good percentage of adherence to the treatment. TPT should be encouraged to achieve the goals of the End TB Strategy of the World Health Organization as an essential strategy to reduce the incidence rate of the disease, but studies with new schemes must continue to be carried out in real-life scenarios.

Major molecular events of reactivation of human cytomegalovirus after allogeneic hematopoietic stem cell transplantation / 器官移植

Immune deficiency of the host caused by allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the initial factor of reactivation of latent human cytomegalovirus (HCMV). The risk factors of reactivation of HCMV in allo-HSCT recipients consist of the serological status of HCMV in donors and recipients, the matching degree of human leukocyte antigen (HLA) and pretreatment patterns, etc. The reactivation of HCMV is associated with the expression of a series of viral cleavage and proliferation proteins induced by the overexpression of major immediate early promoter/enhancer (MIEP) in the viral genome. In this article, the risk factors of reactivation of HCMV after allo-HSCT, the molecular changes related to maintaining latent infection of HCMV, the key role of MIEP overexpression in reactivation of HCMV, and the molecular pathways involved in reactivation of HCMV after allo-HSCT were reviewed and the major molecular events of reactivation of HCMV after allo-HSCT were elucidated, aiming to provide reference for the prevention and treatment of cytomegaloviral disease (CMVD) after allo-HSCT.

Organ transplantation and parasitic infection / 器官移植

Parasitic infection is manifested with the characteristics of both endemic and infectious diseases, and the onset of parasitic infection is regional and infectious. The incidence of parasitic infection after organ transplantation is relatively low, primarily occurring in single case or case series in developing countries and regions. With the development of social economy and a gradual increasing number of organ transplantation, the risk of parasitic exposure is increased when the recipients travel among different countries or regions. In addition, immunosuppression is the risk factor of parasitic infection. Consequently, the risk of parasitic infection in organ transplant recipients cannot be ignored. In this article, epidemiological characteristics, clinical manifestations, diagnosis, treatment and prevention of parasitic infection after organ transplantation were classified and summarized according to literature review, aiming to provide reference for the prevention and treatment of parasitic infection in organ transplant recipients.

Effects of autophagy on viral structures and expression of functional proteins in dorsal root ganglia in a guinea pig model of varicella-zoster virus infection / 中华皮肤科杂志

Objective:To investigate effects of the autophagy inducer rapamycin and autophagy inhibitor 3-methyladenine on viral structures and biosynthesis of functional proteins in dorsal root ganglia in a guinea pig model of varicella-zoster virus (VZV) infection, and to explore their possible mechanisms.Methods:VZV was cultured and proliferated in human embryonic lung fibroblasts (HELFs) , and peripheral blood mononuclear cells (PBMCs) were isolated from guinea pigs. VZV-HELFs and PBMCs were co-cultured for 18-20 hours, and VZV-PBMCs were collected by centrifugation. Thirty-two guinea pigs were randomly and equally divided into 4 groups (8 mice in each group) : blank control group was injected with autologous PBMCs via the medial canthal venous plexus; autophagy inhibition group, autophagy induction group, and VZV infection group were intraperitoneally injected with 3 mg/kg 3-methyladenine solution, 0.5 mg/kg rapamycin solution, and the same volume of 0.9% NaCl solution respectively, followed 2 hours later by injections with 50 μl of VZV-PBMCs via the medial canthal venous plexus. Fourteen days later, the guinea pigs in each group were sacrificed, and dorsal root ganglion tissues were collected. The transmission electron microscope was used to observe the morphology of virus particles, as well as the morphology and number of autophagic vesicles, Western blot analysis was performed to determine the expression of VZV nucleocapsid protein (NCP) , immediate-early protein 62 (IE62) , and autophagy-related proteins Beclin-1 and p62, and immunohistochemical study to determine the expression of anti-VZV antibodies in VZV-infected dorsal root ganglia. Statistical analysis was carried out by using two-independent-sample t test, one-way analysis of variance, least significant difference- t test or Kruskal-Wallis H test. Results:Nucleocapsid-containing virions and scattered autophagosomes were seen in the dorsal root ganglia in the VZV infection group under the transmission electron microscope. The number of autophagic vesicles significantly differed among the blank control group, VZV infection group, autophagy induction group and autophagy inhibition group ( M[ Q1, Q3]: 0, 5[4, 6], 7[5, 9], 0, respectively; H = 135.60, P < 0.01) , and was significantly higher in the VZV infection group than in the blank control group and autophagy inhibition group (both P < 0.05) , as well as in the autophagy induction group than in the autophagy inhibition group ( P<0.05) , but there was no significant difference between the VZV infection group and autophagy induction group ( P>0.05) . Western blot analysis showed that the expression level of IE62 protein was significantly higher in the VZV infection group (1.49 ± 0.06) than in the blank control group (0.50 ± 0.09, t = 9.17, P < 0.05) ; the expression of anti-VZV antibodies was significantly lower in the autophagy inhibition group than in the autophagy induction group and VZV infection group ( t = 9.24, 7.78, respectively, both P < 0.01) , while there was no significant difference between the autophagy induction group and VZV infection group ( P > 0.05) . Conclusion:Autophagy occurred in the dorsal root ganglia of guinea pigs after VZV infection; the inhibition of autophagy could affect the structure of VZV and decrease the expression of VZV functional proteins in the dorsal root ganglia of guinea pigs.

Epstein / 中南大学学报(医学版)

Epstein-Barr virus (EBV), a definite tumorigenic virus, is closely related to the development of nasopharyngeal cancer, gastric cancer, lymphoma and other tumors. EBV encodes a total of 44 mature microRNAs, which can regulate the expression of virus and host genes. EBV-encoded microRNAs and their regulated target molecules participate in the biological functions of tumor apoptosis, proliferation, invasion, and metastasis during tumorigenesis and development, and play an important role in the development of tumor.

Prevalence of latent infection of pathogens of hand, foot and mouth disease in healthy people in China: A meta-analysis / 预防医学

Objective@#To analyze the prevalence of latent infection of pathogens of hand,foot and mouth disease (HFMD) in Chinese healthy population and its influencing factors,so as to provide reference for the prevention and control of HFMD.@*Methods @#Literature on the latent infection of HFMD was searched in Chinese and English databases,such as CNKI,Wanfang,CBMd,PubMed,Web of Science and ScienceDirect,from January 1,2000 to December 31,2019. The pooled rate and its 95% confidence interval(95%CI)were used to assess the latent infection rate of HFMD pathogens in healthy Chinese population.@*Results@#A total of 442 articles were retrieved,and 31 articles were finally included in the quantitative meta-analysis. The results showed that the latent infection rate of human enteroviruses in healthy Chinese population was 18.8%(95%CI:16.1%-21.6%),and the latent infection rates of EV71,CV-A16 and other HEVs were 3.7%(95%CI:2.5%-4.9%),1.9%(95%CI:1.0%-2.9%) and 15.1%(95%CI:11.9%-18.3%),respectively. The latent infection rates of HEVs in healthy men and women in China were 16.7%(95%CI:12.9%-20.4%) and 14.4%(95%CI:10.8%-18.0%),respectively. The latent infection rates of human enterovirues HEVs in the healthy population aged 0-5 years and over 5 years were 24.4%(95%CI:20.4%-28.5%) and 9.4%(95%CI:6.5%-12.2%),respectively. Meta regression analysis showed that the associated factors for the latent infection rate of HEVs in Chinese healthy population included sampling period,sampling area and study population.Sensitivity analysis showed that there was no significant change on meta results after the exclusion of individual studies one by one(p>0.05). Begg's tests,Egger's tests and funnel plots all indicated the existence of publication bias. Trim and fill method showed that the recessive infection rate was reduced after adjustment(p<0.05). @*Conclusions@#The latent infection rate of HFMD pathogens is high in healthy people in China,and it is mainly caused by other HEVs. Males and children aged under 5 years are at high risk of latent infection of HEVs.

Research progress on human herpesvirus 6 infection after liver transplantation / 器官移植

Human herpesvirus 6 (HHV-6) may establish lifetime latency after initial invasion of the host, and liver transplant recipients may experience reactivation of latent infection during immunosuppression. HHV-6 infection in liver transplant recipients could lead to fever, hepatitis, encephalitis and graft dysfunction, and indirectly increases the risk of progression of liver fibrosis due to cytomegalovirus (CMV), hepatitis C virus (HCV) infection. At present, the pathogenesis of HHV-6 infection after liver transplantation has not been systematically elucidated, and effective prevention and treatment strategies are still lacking. This article provided a review for the research progress on the pathogenesis, risk factors, diagnosis and treatment of HHV-6 infection after liver transplantation.

Prevalence of severe fever with thrombocytopenia syndrome virus infection in Zhoushan island and duration of serum positive IgG antibody in infected patients / 中华临床感染病杂志

Objective@#To analyze the prevalence of severe fever with thrombocytopenia syndrome virus(SFTSV)infection in Zhoushan island of Zhejiang province and the duration of serum positive IgG antibody in patients infected with SFTSV.@*Methods@#One thousand one hundred and twenty-two healthy people from Zhoushan island of Zhejiang province were recruited for cross-sectional study in August 2019, including 641 from non-epidemic areas and 481 from epidemic areas. The serum SFTSV-IgG antibody was detected by enzyme-linked immunosorbent assay (ELISA), and the positive rates of SFTSV-IgG antibody were compared between people from the epidemic areas and non epidemic areas. Meanwhile, the antibody titer of SFTSV-IgG in 19 patients confirmed between July 2011 and June 2018 was detected by indirect ELISA. SPSS 17.0 software was used to analyze data.@*Results@#The positive rate of SFTSV-IgG antibody was 1.5% (7/481) in the epidemic area, which was higher than that in the non-epidemic area (0/641) (χ2=7.187, P<0.01). The positive rates of SFTSV-IgG antibody in 2019 were lower than those in the epidemic area (11.7%) and non-epidemic area (2.5%) in 2013 (χ2=22.556 and 10.352, both P<0.01). The serum SFTSV-IgG antibody of 18 patients with previous infection was still positive, and the longest one lasted for 8 years.@*Conclusions@#There is a SFTSV latent infection in population from epidemic area of Zhoushan island. The SFTSV-IgG antibody can last for a long time in patients with SFTS and it may have certain protective effect.

Mechanism of herpes virus latent infection and its significance / 白血病·淋巴瘤

Human herpes virus (HHV) spreads widely in a latent-infected way. HHV is divided into 3 kinds and 8 types. Herpes simplex caused by HHV-1 and HHV-2, varicella-zoster caused by HHV-3 and Epstein-Barr virus (EBV) known as HHV-4 and recognized firstly as human tumor virus, are well known in the field of virology. With the application of hematopoietic stem cell transplantation , cytomegalovirus (HHV-5) and HHV-6 have gained an increasing attention. The biological characteristic of HHV is latent infection in a long time and HHV can be reactivated in some immunocompromised individuals. Clarification of latent infection mechanism will help provide targets for therapy and lay a foundation for clinical treatment. This paper summarizes the clinical significance of HHV infection. Taking the mechanism of EBV latent infection as an example, the pathway and significance as well as strategy of co-evolution of organism and virus will be discussed in order to provide clues for prevention and therapy.

Progress in studies on mechanism of immune evasion of Epstein-Barr virus / 中华实验和临床病毒学杂志

Epstein-Bar virus (EBV) infection is widespread within the human population with over 95% of adults being infected. In response to primary EBV infection, the host mounts an antiviral immune response comprising both innate and adaptive immune system. In healthy populations, the immune system can control EBV infection to a large extent. However, the virus cannot be cleared. Instead, EBV establishes a persistent latent infection in B lymphocytes characterized by limited viral gene expression. To establish a persistent infection efficiently, EBV have evolved a number of strategies to avoid immune elimination. In this review, we focus on the immune evasion mechanisms of EBV encoded immune-evasion proteins, microRNA and host exosome pathway.

Progress of EB virus related lymphomas / 白血病·淋巴瘤

The occurrence and development of some lymphomas are closely related to EB virus, including B cell lymphoma, NK/T cell lymphoma, Hodgkin lymphoma and post-transplant lymphoproliferative disorder. Many studies have shown that some gene expression products that related to EB virus latent infection play a crucial role in the development of lymphoma. In this paper, the structure and biological characteristics of EB virus, its gene expression products, the mechanism of tumorigenesis and the related lymphomas are reviewed.

Tracking of herpesviruses: what have been seen and will be seen? / 生物工程学报

Viral infection of cells is a highly intricate process that involves the complex virus-cell interactions. Recently, virologists can monitor the virus life cycle at the primary infection site in real-time using various virus tracking techniques. Herpesviruses, a class of large enveloped DNA viruses, are important pathogens threatening the health of humans and animals. This review discussed the applications of different virus tracking techniques in herpesvirus studies, to provide new insights into virus-cell interactions and replication mechanisms of herpesviruses. Though the techniques have widely been exploited, some issues need to be addressed, such as the selection of the optimal site to insert reporters and the inability to track the whole process of the virus life cycle. With the updated tracking techniques, hopefully, more complex replication mechanismsof herpesviruses will be revealed in detail.

Research progress of AIDS treatment / 中国人兽共患病学报

AIDS antiviral therapy (ART) has achieved great success.Originaly,AIDS had been regarded as a fatal disease,but it has become a kind of infectious disease that could be cured and administrated.Global HIV / AIDS cases were still up to about 38 million,but more than half have been effectively treated.In addition to drug treatment,at present,some new technologies and new methods,such as genome editing,have also been involved in the treatment of AIDS,and in the humanized animal experiment has shown very good results.There is no doubt that AIDS will eventually be stopped its epidemic.However,with the continuous development of AIDS antiviral treatment,the most fundamental problem is that HIV latent library has become increasingly prominent one,whether molecular therapy and hybrid cure have being developed for AIDS treatment,there are still such problem existence.Great efforts shoud be made to continuously search for new markers of latent viral cells and to reduce the latent pool.In addition,despite the prevention and treatment of AIDS has made great achievements,but the world still produces nearly 6000 cases of HIV/AIDS every day.Therefore,the development of safe and effective vaccine,whether in the field of prevention,or in clinical treatment,has its positive significance.

Risk factors for latent tuberculosis in children who had close contact to households with pulmonary tuberculosis

PURPOSE: Tuberculosis (TB) is a common and possibly fatal infectious disease, and its incidence and prevalence is quite high in Korea compared to other Organization for Economic Co-operation and Development countries. Patients who have active TB can cause latent tuberculosis infection (LTBI) in children, which may progress to reactivated tuberculosis. This study was performed to analyze the risk of adult TB that affects children's LTBI. METHODS: From June 2013 to May 2014, 60 children (32 boys, 28 girls) who came into close contact with adult patients diagnosed with pulmonary TB underwent LTBI tests. The children were divided into the 2 groups: the first group was finally diagnosed to LTBI, and the second group was proven not to have LTBI. We compared the risk of adult patients with pulmonary TB between children with LTBI and those without through a medical record review. RESULTS: The number of adult patients with TB was 36 (father 68%, mother 23%, grandparents 8%). The patients who came into close contact with the LTBI group were older (47.0±12.8 years vs. 41.3±6.6 years) and had higher erythrocyte sedimentation rate (ESR) levels than those of the second group. The rate of negative acid-fast-bacilli smear with positive culture results in patients who came into contact with the LBTI group was higher than in the second group. The cutoff value of ESR for the diagnosis of LTBI was 31 mm/hr with a sensitivity of 0.75 and a specificity of 0.85 (area under curve=0.748). CONCLUSION: Adult pulmonary TB patients who are older and have higher ESR levels may be risk factors for LTBI in children coming into close contact with them.

HCMV-encoded miRNA during latent infection / 军事医学

Objective To explore humam cytomegalovirus(HCMV) encoded microRNAs during latent infection in order to help study HCMV virology and latent infection mechanisms.Methods A model of HCMV latent infection via THP-1 cells infected with HCMV was constructed.Deep-sequencing was performed using high-resolution Solexa sequencing platform.The secondary structure of the newly sequenced miRNA was predicted by RNAFold bioinformatics software. Results HCMV encoded various miRNAs during latent infection, including miR-US25-2-3p, miR-US25-2-5p, miR-UL112, miR-US25-1, miR-UL22A and PC-5p-148467 with a predicted length of 25 bp, named hcmv-miR-US33as-5p.Conclusion HCMV can express many types of miRNAs during latent infection.

Constructing a recombinant adenovirus carrying human cytomegalovirus UL138 gene and evaluating the effects of UL138 gene on the functions of monocytes / 中华微生物学和免疫学杂志

Objective To construct a recombinant adenovirus carrying UL138 gene, which was re-lated to the latent infection of human cytomegalovirus, and to investigate the effects of UL138 gene on the functions of THP-1 mononuclear cells. Methods The recombinant adenovirus expressing the UL138 gene was packaged. The titer of the recombinant adenovirus was determined by calculating 50% tissue culture in-fective dose ( TCID50 ) . THP-1 mononuclear cells were infected with the recombinant adenovirus at different multiplicity of infection (MOI) and the optimal MOI was determined (100 PFU/cell) by observing the ex-pression of green fluorescent protein ( GFP ) . Changes in the expression of proinflammatory cytokines by THP-1 mononuclear cells that was induced by overexpressed UL138 were analyzed by quantitative PCR. The expression of chemokines and their receptors were measured by quantitative PCR array. Results The re-combinant adenovirus carrying the UL138 gene was successfully constructed with a titer of 1×1011 PFU/ml. The rate of THP-1 mononuclear cells that was infected with the recombinant adenovirus was 60% at the MOI of 1 ∶ 100. Results of the RT-PCR analysis and Western blot assay further confirmed that the recombinant adenovirus could infect THP-1 mononuclear cells successfully and the expression of UL138 protein increased gradually over time. The overexpressed UL138 in THP-1 mononuclear cells significantly inhibited the expres-sion of IL-18, IL-1β, IL-6, IL-8 and TNF-α as indicated by the results of quantitative PCR. Results ob-tained from the quantitative PCR array analysis showed that most of the chemokines and their receptors were downregulated in the transfected THP-1 mononuclear cells except for the chemokines of CCL17, CCL21, CCL2 and XCL2 and the receptors of CCR2, CXCR1, CXCR2, CXCR4 and CX3CR1 which were upregulat-ed. Conclusion We successfully constructed the recombinant adenovirus carrying UL138 gene which could be used to infect THP-1 mononuclear cells. Overexpressed UL138 in THP-1 mononuclear cells significantly affected the functions of THP-1 mononuclear cells.

Nuevas perspectivas terapéuticas en tuberculosis / New perspectives in tuberculosis treatment

To advance in the control and elimination of tuberculosis (TB) we must achieve a high level of effectiveness in the prevention of TB in populations infected by Mycobacterium tuberculosis. Latent TB prevention success with current therapies (single isoniazid or in combination with rifampicin) is close to 60%. We also must offer a high level of treatment success in first-line drugs sensitive TB patients. With currently available drugs (isoniazid, rifampicin, ethambutol and pyrazinamide) treatment success should reach at least 95%. Drug side reactions together with the lengthen treatment of infection and disease (6 months) decrease the compliance to these therapies. In Multi-Drug-Resistant TB (MDR-TB), therapies are even longer (20 months according to WHO's recommendation) and much less tolerated, with rates of success under 50%. New trials for latent TB using rifapentin and isoniacid; combined fixed-dose offirst-line drugs in sensible TB, and the addition of new drugs (fluorquinolones, bedaquiline, delamanid and linezolid) in multi-drug resistant TB, together with shorter regimens of 12 months duration which include Clofazimine (experience in Cameroon with modification of a 9 months trial previously used in Bangladesh showing 89% cure) are discussed in this article.

Para el control y eliminación de la tuberculosis se debe lograr un alto grado de eficacia en la prevención del desarrollo de tuberculosis en la población infectada por Mycobacterium tuberculosis. Esta prevención, con las terapias actuales de la tuberculosis latente (isoniazida sola o combinada con rifampicina), es cercana al 60%. También debemos alcanzar una alta tasa de curación para los enfermos con tuberculosis sensible a los fármacos de primera línea (vírgenes a tratamiento). Con los fármacos actualmente disponibles (isoniazida, rifampicina, etambutol y pirazinamida) esta curación debería alcanzar a no menos del 95%. La regular tolerancia y reacciones colaterales de los fármacos y el largo tiempo que demandan las terapias de la infección y de la enfermedad (6 meses) atenta contra su adherencia. En el caso de la Tuberculosis Multi-Drogo-Resistente (TB-MDR), los tratamientos son aún más prolongados (20 meses según recomienda la OMS actualmente) y menos tolerados, siendo sus tasas de curación inferiores a 50%. Se analizan nuevos esquemas para el tratamiento de la tuberculosis latente usando rifapentina asociada a isoniacida; dosis fijas combinadas de fármacos de primera línea para tuberculosis sensibles, y asociación de fármacos antiguos y nuevos (fluoroquinolonas, bedaquilina, delamanid y linezolid) para el tratamiento de las tuberculosis multirresistentes. También se presentan nuevos esquemas acortados, de 12 meses de duración, que incluyen clofazimina (experiencia en Camerún con modificación del esquema de 9 meses usado previamente en Bangladesh, con tasas de curación de 89%).

Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in polymorphonuclear cells during latent tuberculous infection

It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals.

Prescription pattern of tuberculin skin test (TST) in a teaching hospital.

Background: Tuberculin skin test (TST) is one of the tools for the identification of latent tubercular infection and is an ancillary test for diagnosis of active tuberculosis. Aims & Objective: The objective of this study was to assess specialty department wise prescription of Tuberculin Skin Test (TST) in a government teaching hospital. Material and Methods: Considering resource constraint and feasibility, one month was randomly selected during 2012 and two working days in each week were systematically covered i.e. Mon-Tue (first week), Wed-Thus (second week), Fri-Sat (third week) and again Mon-Tue (fourth week). Selected information of all patients reporting to receive TST on these days was recorded on a pre-structured proforma. TST was administered by a single investigator using standard protocol and results observed between 48-72 hours. Results: A total of 372 ambulatory suspect TB patients reported to received TST with mean age of 25 years (±18.13); female constituted 52.4%. Specialty department wise prescription of TST was as follows: paediatrics (29.3%); general medicine (18.0%); OBG (15.9%); surgery (12.9%); chest and TB (11.3%), orthopaedics (8.1%) and others (4.6%). The results of 227 (61.02%) patients who returned for follow up were grouped into < 10 mm (54.0%) and ≥ 10 mm (45.79%). Conclusion: Proportion of age distribution of patients in study sample was found to be similar in comparison to population structure of India. Paediatric (up to 14 years) patients were in majority (29.3%) amongst study samples where TST results could be of some significance.