Tracing the journey of poxviruses: insights from history.

The historical significance of the poxviruses is profound, largely due to the enduring impact left by smallpox virus across many centuries. The elimination of smallpox is a remarkable accomplishment in the history of science and medicine, with centuries of devoted efforts resulting in the development and widespread administration of smallpox vaccines. This review provides insight into the pivotal historical events involving medically significant poxviruses. Understanding the remarkable saga of combatting smallpox is crucial, serving as a guidepost for potential future encounters with poxvirus infections. There is a continual need for vigilant observation of poxvirus evolution and spillover from animals to humans, considering the expansive range of susceptible hosts. The recent occurrence of monkeypox cases in non-endemic countries stands as a stark reminder of the ease with which infections can be disseminated through international travel and trade. This backdrop encourages introspection about our journey and the current status of poxvirus research.

Rabies control in high-burden countries: role of universal pre-exposure immunization.

Rabies is a fatal zoonotic encephalitis that is responsible for approximately 59,000 deaths worldwide every year. A significant portion of these deaths, about one-third, occur in India alone. In order to meet the World Health Organization's objective of eliminating dog-mediated rabies by 2030, India has made considerable progress in this regard. However, implementing the current strategies of canine immunization, sterilization, and providing post-exposure prophylaxis to exposed individuals is challenging in a large and diverse country like India. This article aims to highlight the limitations of relying solely on post-exposure prophylaxis for the prevention of human rabies. Moreover, it presents the necessity and rationale for including pre-exposure immunization in India's national immunization schedule.

Evaluation of a rapid, chip-based, micro-PCR assay for detection of rabies virus in human and canine specimens.

Rabies, a lethal zoonotic encephalitis, remains a significant global health concern, causing an estimated 60 000 annual fatalities worldwide. Dogs serve as the primary reservoirs and vectors for transmitting this infection to humans. Definitive diagnosis of rabies in both human and animal cases necessitates laboratory testing involving various clinical specimens. However, the complexity of laboratory infrastructure and the need for skilled personnel, along with the challenge of maintaining cold-chain integrity during sample referral, hinder the decentralization of diagnostic facilities. This study aimed to assess the efficacy of the Truenat rabies assay, a rapid, portable, semiautomated, and closed PCR-based system, for the diagnosis of rabies in both humans and animals. The Truenat assay demonstrated a sensitivity of 100% and a specificity of 86.96% when compared with the fluorescent antibody test (FAT), as the reference standard, on 147 canine brain samples tested. Notably, the Truenat assay exhibited a sensitivity and specificity of 100% when tested on 48 human brain specimens. Furthermore, an examination of 148 human antemortem samples (cerebrospinal fluid, saliva, and skin biopsy) using both the Truenat assay and a validated real-time reverse transcriptase PCR assay revealed a κ value of 0.505, indicative of a moderate level of agreement between the two tests. Thus, the Truenat assay offers a robust, reliable, and affordable point-of-care solution to enhance rabies diagnostic capacity in endemic areas.

SARS-CoV-2 and the nervous system: current perspectives.

SARS-CoV-2 infection frequently causes neurological impairment in both adults and children. Recent publications have described significant aspects of the viral pathophysiology associated with neurological dysfunction. In theory, neurological manifestations following SARS-CoV-2 infection may be caused directly by the effects of the virus infecting the brain or indirectly by the local and systemic immune responses against the virus. Neurological manifestations can occur during the acute phase as well as in the post-acute phase of the infection. In this review, we discuss recent literature describing the association of nervous system disorders with COVID-19.

Diagnostic Performance of Multiplex PCR for Detection of Mycobacterium tuberculosis Complex in Presumptive Pulmonary Tuberculosis Patients and Its Utility in Smear Negative Specimens.

Objective The primary objective of this study was to assess the diagnostic performance of multiplex polymerase chain reaction (mPCR) for the detection of Mycobacterium tuberculosis complex (MTBC) in presumptive pulmonary TB patients, in the setting of a tertiary level teaching hospital in central India, in comparison to liquid culture using BACTEC mycobacteria growth indicator tubes (MGIT) 960 TB system as the gold standard. The secondary objective was to assess the performance of mPCR for Ziehl Neelsen smear negative samples and ascertain the utility of this assay in smear negative samples. Materials and Methods Sputum or bronchoalveolar lavage samples were collected from patients who were adults, aged 18 years or older, presenting with presumptive pulmonary TB, and subjected to three microbiological investigations, that is, Ziehl Neelsen staining, mycobacterial culture using mycobacterial growth indicator tubes in the BD BACTEC MGIT 960 instrument, and the mPCR. Statistical Analysis For statistical analysis, 2 × 2 contingency tables were prepared and analyzed separately for all samples and for smear-negative samples using GraphPad and MedCalc tools. Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of mPCR were calculated by taking MGIT culture as the reference standard. Results For all samples ( n = 114), sensitivity of mPCR for the detection of (MTBC) was 93.48% (95% confidence interval [CI]: 82.10-98.63%), specificity was 95.59% (95% CI: 87.64-99.08%), positive predictive value (PPV) was 93.48% (95% CI: 82.54-97.75%), and NPV was 95.59% (95% CI: 87.87-98.48%). For smear negative samples ( n = 80), sensitivity was 80.00% (95% CI: 51.91-95.67%), specificity was 98.46% (95% CI: 91.72-99.96%), PPV was 92.31% (95% CI: 62.80-98.84%), and NPV was 95.52% (95% CI: 88.57-98.33%). Conclusion In this study, we were able to demonstrate the good performance characteristics of the mPCR for the detection of MTBC from clinical samples of patients with presumptive pulmonary tuberculosis, with MGIT liquid culture as the reference standard. It may be concluded that mPCR can be considered equivalent to MGIT culture in terms of clinical decision making and yield of positivity, owing to the good sensitivity and specificity for the detection of MTBC.

Aeromonas salmonicida urinary tract infection in a newly diagnosed AIDS patient on antitubercular treatment.

Aeromonas salmonicida is a well-known pathogen in salmonid fishes. It was believed to be non-pathogenic to humans because of inability to grow at 37°C. Here we present a case of a woman in her 20s who was diagnosed with abdominal tuberculosis 6 months previously but had not been compliant with the treatment. She presented with occasional febrile episodes, whitish vaginal discharge, burning micturition, anal ulcer, whitish discharge from mouth and recent onset breathlessness. Patient tested serologically positive for HIV-1, and A. salmonicida was isolated from urine sample. Patient was treated with antituberculosis therapy, antiretroviral therapy and antimicrobials. She showed marked improvement over the next few weeks. This case highlights the importance of recognition of rare organisms, especially in immunocompromised patients. The identification and subsequent treatment of such pathogens have improved since the advent of automated identification systems.