Publications by authors named "John A J Prakash"

Introduction: The diagnosis and detection of pathogens such as and is a cause of major concern among the public health community. Unavailability of rapid, cost-effective diagnostic assays contributes to delayed diagnosis and timely treatment. Using the methodology of systematic reviewing and meta-analysis, the study aimed to synthesize and compare the diagnostic performances of all the available isothermal assays for the detection of classical rickettsial diseases.

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Article Synopsis
  • Orientia tsutsugamushi, the cause of scrub typhus, was successfully isolated from patients' blood cells at a healthcare center in Vellore, Southern India.
  • Researchers cultured and tested samples using various methods over 30 days, ultimately confirming three positive isolates through qPCR and other staining techniques.
  • Genotyping revealed the isolates belonged to TA763 and Gilliam genotypes, marking the first successful isolation of this pathogen in the region, with potential for further genomic study.
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Introduction: Anti-neuronal antibodies target antigens produced by tumour cells and cells of nervous system. These antibodies are formed as a result of autoimmune response elicited by the underlying malignancy, when proteins restricted to immune privileged neurons are presented by the tumour. Previous studies have shown presence of anti-neuronal antibodies in systemic lupus erythematosus and neuropsychiatric lupus (NPSLE) but information on individual antibodies and their pathogenic role is lacking.

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This study aimed to assess the molecular prevalence of mite-borne zoonotic pathogen O. tsutsugamushi in household rats of South India through nested polymerase chain reaction amplification of O. tsutsugamushi 47-kDa htrA gene and to determine the most suitable sample type for screening of O.

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Objectives: To determine whether rituximab (RTX) is effective in 'treatment-naïve' idiopathic inflammatory myopathies (IIM), and whether there could be differential treatment responses between 'treatment-naïve' and treatment 'refractory' IIM.

Methods: Data were obtained from a prospectively maintained database comprising patients with IIM treated with RTX. Patient details were obtained at baseline, 3- and 6-months intervals, and at subsequent follow-up visits.

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The nature of vaccine response inferiority is not well studied in children living with HIV (CLHIV). The authors investigated Hepatitis B Virus (HBV) and Diphtheria/Pertussis/Tetanus toxoid (DPT) vaccination responses following primary immunization in CLHIV (n = 42) and healthy controls (HC) (n = 38) and the effect of an additional vaccine dose. Antibody responses, CD4 and HBV-specific T/B cells were analysed using CMIA/ELISA and flow-cytometry.

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Introduction: The current systematic review aimed to collect and analyze the comprehensive evidence regarding Polymerase Spiral Reaction (PSR) and to estimate its diagnostic performance and usefulness as a point-of-care (PoC) assay.

Methods: Literature was retrieved systematically from 2015 to 2023 from PubMed and Scopus. Studies were screened and selected against pre-determined inclusion and exclusion criteria.

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Climate is one of the major factors determining the prevalence and seasonality of vector borne diseases like scrub typhus (ST). We analyzed, the association of the meteorological factors like temperature, rainfall and humidity with scrub typhus using the 15 years scrub typhus data from a tertiary care hospital in Vellore, South India. Demographic data of permanent residents of Vellore, who had IgM ELISA results for scrub typhus for the time period of May 2005 to April 2020 were included.

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Purpose: The immunodominant TSA 56 gene of Orientia tsutsugamushi, (scrub typhus agent) has four variable regions (VD-I to VD-IV) making it useful for genotyping. This study was undertaken to determine Orientia tsutsugamushi genotypes circulating in and around Vellore using complete and partial TSA 56 gene.

Methods: Of the 162 patients positive by 47 ​kDa qPCR, on 21 samples PCR to amplify the complete TSA 56 gene (≈1605 bp: Long protocol) and the partial gene sequence using the Horinouchi (≈650bp) and the Furuya (≈480 bp) protocol was performed.

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Introduction: Myositis-specific antibodies (MSA) play an important role in the clinical presentation and prognosis of patients with idiopathic inflammatory myositis (IIM). Anti-NXP-2 is one of the newly described MSA.

Objective: We aimed to describe various clinical presentations associated with anti-NXP2 antibodies and assess response to treatment.

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Purpose: Brucellosis is a bacterial zoonotic disease caused by genus Brucella. The disease is often transmitted to humans by direct or indirect contact with infected livestock or from laboratory exposure. In this study two clinical isolates of Brucella melitensis were subjected to whole genome sequencing (WGS) using Ion Torrent PGM and Oxford Nanopore MinIon platform.

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Background is an opportunistic pathogen causing severe infections, including bacteremia. There have been increased reports of antimicrobial resistance in . However, phenotypic testing of susceptibility is time consuming and not cost effective for anaerobes.

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Article Synopsis
  • A 53-year-old male with a history of untreated primary syphilis experienced flaccid quadriparesis, sensory loss, and bladder dysfunction, leading to a diagnosis of tract-specific myelopathy associated with neurosyphilis.
  • MRI findings showed unique symmetric hyperintensities in the cervical spinal cord that are distinct from typical presentations of syphilitic meningomyelitis.
  • The patient improved significantly after penicillin treatment, highlighting the importance of early diagnosis and intervention in unique cases of myelopathy related to neurosyphilis.
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Background: The appropriate antibiotic treatment for severe scrub typhus, a neglected but widespread reemerging zoonotic infection, is unclear.

Methods: In this multicenter, double-blind, randomized, controlled trial, we compared the efficacy of intravenous doxycycline, azithromycin, or a combination of both in treating severe scrub typhus. Patients who were 15 years of age or older with severe scrub typhus with at least one organ involvement were enrolled.

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Purpura fulminans (PF) is associated with acute infections such as meningococcal, staphylococcal, streptococcal, and rickettsial infections. However, there are only a few reports of association of PF with rickettsial fever from India. In this case series of seven adults with PF, four were definitive cases of spotted fever as the ompA real-time polymerase chain reaction was positive.

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Rickettsial infections and Q fever are a common cause of acute febrile illness globally. Data on the role of climate and altitude on the prevalence of these infections in lacking from Southern India. In this study, we determined the sero-prevalence of scrub typhus (ST), spotted fever (SF), murine typhus (MT) and Q Fever (QF) in 8 eight geographical regions of North Tamil Nadu by detecting IgG antibodies using ELISA.

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Allergic rhinitis (AR) is recognized as a growing global health disease with considerable importance among children and adolescents. This study aims to study the clinical and sensitization profile of children with allergic rhinitis using EAST. All children presenting to pediatric ENT outpatient with a clinical diagnosis of AR were prospectively recruited.

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Commercial dengue virus (DENV) nonstructural-1 (NS1) Ag detection immunoassays often perform poorly, particularly in secondary DENV infection. To develop a highly sensitive NS1 ELISA, we generated a large repertoire of anti-DENV NS1 mouse mAbs (n = 95) that falls into 36 mAb classes based on binding specificities. The identified mAb pair, capable of efficiently detecting NS1 from four DENV serotypes in an immunoassay, was selected based on multiparametric analysis.

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Early detection and treatment of a colorectal anastomotic leak reduces leak-associated morbidity. The primary objective of this study was to assess the role of C-reactive protein (CRP) as a tool to facilitate the early diagnosis of large bowel anastomotic leak. We conducted a prospective observational study at a specialized colorectal unit of a tertiary referral teaching center where we recorded CRP levels pre-operatively and on day three for 113 patients undergoing a large bowel anastomosis.

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The performance of enzyme linked immunosorbent assays (EAST) for identifying six indoor allergens was evaluated using skin prick test (SPT) as reference tests in 154 children with allergic rhinitis. Sensitivity of EAST ranged from 9% (cat) to 54% (HDM) with specificity of 74%(cockroach) to 100% (cat) with an agreement ranged from 58 to 86%. Cut off values ​> ​0.

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Scrub typhus is a common bacterial infection in Asia caused by . This serological cohort study estimated the incidence of infection in a rural population in South India. Participants were enrolled through systematic sampling in 46 villages at baseline, and revisited the following year.

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Background And Objectives: To determine the real-world data regarding the use of Rituximab (RTX) in neuroinflammatory disorders (NIDS) and assess the outcomes following RTX treatment.

Methods: A cohort of consecutive patients with NIDS started on RTX (2018-2020) was included. The outcomes assessed were the proportion with favourable clinical response (FCR) as defined by clinical remission/ improvement using disease specific disability scores, comparative efficacy based on timing of initiation and B cell kinetics.

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Detection of Orientia tsutsugamushi DNA in a trombiculid mite chigger species suggests that it might be a potential vector of scrub typhus in an endemic area. Over a period of 20 mo, 85 rats were trapped, 57 had chiggers that were identified by standard morphometric techniques. The chigger pools were assessed by performing PCR assays targeting fragments of the single-copy genes 56 kDa type-specific antigen gene (TSA56) by nested PCR and the 47 kDa (htrA) quantitative real-time PCR (qPCR).

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Objective: The clinical and serological characteristics of spotted fever group rickettsial (SFGR) infections in South Asia are poorly understood. We studied the clinical presentation and the IgM/IgG response in cases enrolled at two health care centres in South India.

Method: We enrolled 77 patients.

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Spondylodiscitis is an infectious inflammation that affects the intervertebral disc and adjacent structures. Treating infective spondylodiscitis is often challenging due to the lack of specific symptoms. Here we present an unusual case of infective spondylodiscitis caused by subsp.

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