Aetiological profile of acute encephalitis syndrome in Assam, India, during a 4-year period from 2019 to 2022.

Acute encephalitis syndrome (AES) is a major public health concern in India as the aetiology remains unknown in the majority of cases with the current testing algorithm. We aimed to study the incidence of Japanese encephalitis (JE) and determine the aetiology of non-JE AES cases to develop an evidence-based testing algorithm. Cerebrospinal fluid (CSF) samples were tested for Japanese encephalitis virus by ELISA and polymerase chain reaction (PCR). Multiplex real-time PCR was done for Dengue, Chikungunya, West Nile, Zika, Enterovirus, Epstein Barr Virus, Herpes Simplex Virus, Adenovirus, Cytomegalovirus, Herpesvirus 6, Parechovirus, Parvovirus B19, Varicella Zoster Virus, Scrub typhus, Rickettsia species, Leptospira, Salmonella species, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Plasmodium species and by ELISA for Mumps and Measles virus. Of the 3173 CSF samples, 461 (14.5%) were positive for JE. Of the 334 non-JE AES cases, 66.2% viz. Scrub typhus (25.7%), Mumps (19.5%), Measles (4.2%), Parvovirus B19 (3.9%) Plasmodium (2.7%), HSV 1 and 2 (2.4%), EBV and Streptococcus pneumoniae (2.1% each), Salmonella and HHV 6 (1.2% each) were predominant. Hence, an improved surveillance system and our suggested expanded testing algorithm can improve the diagnosis of potentially treatable infectious agents of AES in India.

Livestock, pets and humans as carriers of methicillin-resistant Staphylococcusaureus and comparative evaluation of two PCR protocols for detection.

Staphylococcus aureus are Gram positive bacteria known to acquire antibiotic resistance rapidly and pose a major challenge to clinicians worldwide. Infections by methicillin resistant Staphylococcus aureus (MRSA) are usually associated with increased mortality and prolonging of treatment. Samples (n = 706) from diverse sources (livestock, pets, animal handlers, human hospital) were collected and screened for the presence of MRSA by phenotypic and genotypic methods. The incidence of Staphylococcus aureus was greater in goats (42.00%; 28.20 - 56.80%, confidence interval [CI] 95.00%) followed by cattle (13.50%; 9.20 - 18.80%, CI 95.00%), humans (12.90%; 9.30 - 17.40%, CI 95.00%) and dogs (12.90%; 8.10 - 19.20%, CI 95.00%). Significantly higher incidence of MRSA was observed in dogs (65.00%; 40.80 - 84.60%, CI 95.00%), compared to other hosts namely cattle (48.00%; 26.50 - 64.30%, CI 95.00%), humans (35.00%; 20.20 - 52.50%, CI 95.00%) and goats (10.00%; 1.20 - 30.40%, CI 95.00%). All the S. aureus isolates were further screened for thermostable nuclease (nuc gene) by polymerase chain reaction (PCR). The incidence of nuc gene in cattle, dog, goat and human were found to be 3.30% (1.30 - 6.60%, CI 95.00%), 5.20% (2.30 - 9.90%, CI 95.00%), 28.00% (16.20 - 42.50%, CI 95.00%) and 9.10% (6.00 - 13.00%, CI 95.00%), respectively. Comparative evaluation of two PCR primers (mecA-162 and mecA-310) indicated the former one as more rational choice for detection of MRSA. Overall, the results of our study indicated possible risk of zoonotic transmission of MRSA from canines.