Trends in the Seroprevalence of Dengue in a Tertiary Care Hospital of North Karnataka, India

Introduction: Dengue virus of the Flaviviridae family is the causative agent of dengue fever. The Aedes aegypti mosquito is the main vector for its transmission. Though, the cases of dengue fever are mild and self-resolving, there can be fatal complications like Dengue Haemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). Aim: To study the trends in the seroprevalence of dengue in serum samples of suspected cases. Materials and Methods: The present study was a crosssectional study which was conducted from January 2017 to December 2019, at Belagavi Institute of Medical Sciences (BIMS), Belagavi, Karnataka, India. The serum samples were collected from suspected dengue fever cases and tested by Immunoglobulin M (IgM) capture Enzyme Linked Immunosorbent Assay (ELISA), to detect IgM antibody against dengue virus and NS1 capture ELISA for dengue NS1 (nonstructural protein 1) antigen using ELISA kits manufactured by National Institute of Virology (NIV), Pune. The tests were performed according to the manufacturer’s instruction. The data obtained from the study was analysed using descriptive statistics. Results: A total of 8,992 serum samples were tested over a period of three years, of which 1,340 (14.90%) were positive for dengue infection. Among which 1,048 (78.21%) were positive for anti-dengue IgM antibodies, 109 (8.13%) were positive for NS1 antigen and 183 (13.66%) were positive for both. Most affected age group was 11-20 years and male to female ratio was 1.18:1. The seasonal peak was observed in monsoon i.e. month of June (15.52%) followed by August (12.02%). Conclusion: Seroprevalence of dengue infection being critical signifies the importance of detection of both IgM antibodies and NS1 antigen for diagnosis of dengue infection. The study also identifies younger population being at higher risk and also monsoon as the most favourable season for viral transmission in this region and highlights the importance of concerted efforts towards disease control and prevention

AN EXPERIENCE OF HANDLING MICROBIAL CONTAMINATION OF PRODUCT WATER AT A HAEMODIALYSIS UNIT IN NORTH KARNATAKA OF INDIA

BACKGROUND Dialysis units need regular prophylactic disinfection of the dialysis water production and distribution circuit without which there can be chronic inflammation among patients using the facility. The aim of the study is to present here our experience in containing an episode of microbial contamination of dialysis water. MATERIALS AND METHODS Our haemodialysis unit had a single pass reverse osmosis plant with facility for pretreatment of raw water and a distribution loop of medical grade PVC (polyvinyl chloride) feeding haemodialysis machines, bicarbonate preparation and dialyser reprocessing areas. After installation, the Reverse Osmosis (RO) membranes and distribution loop were disinfected every fortnight using formalin. Cultures of product water were sent from various sites in the product water loop every month. RESULTS From January to April 2011, 15 water samples out of 52 water samples grew Pseudomonas aeruginosa with a colony count over 200 Colony-Forming Units (CFU). The average monthly number of haemodialysis was reduced from 84.75 to 65. Two patients had intradialytic pyrexia and two others had mild lower respiratory infection. So, the reverse osmosis plant and product water distribution system were repeatedly disinfected using 2% formalin and 1% bleach ensuring contact time and thorough rinsing to address persistent cultures. When these measures could not eradicate microbial growth, the system was sanitised with Gramicid (48% w/w H2O2 + 500 ppm Ag) and all traces of the disinfectant were rinsed away before resuming haemodialysis. CONCLUSION The microbial contamination of dialysis water was eradicated by Gramicid and not by bleach or formalin without any adverse effects after thorough rinsing

ELISA versus Conventional Methods of Diagnosing Endemic Brucellosis

The diagnostic value of enzyme-linked immunosorbent assay (ELISA) was evaluated when blood specimens of 92 patients suspected of brucellosis underwent the ELISA (IgM and IgG), standard tube agglutination (SAT), and 2-mercaptoethanol (2-ME) tests and blood cultures; 38 sera from non-brucellosis patients and 34 sera from blood donors were also subjected to ELISA, SAT, and 2-ME tests. SAT was able to pinpoint only 23 (25%), whereas ELISA confirmed the etiology in 56 (60.9%; P < 0.001) patients with brucellosis, including 31 culture-confirmed cases. The sensitivity and specificity of ELISA were 100% and 71.31%, respectively. Because they were confirmed by ELISA, the diagnosis could never be excluded with SAT in 33 cases. ELISA has been found to be more sensitive in acute (28% higher sensitivity; P < 0.02) and chronic (55% higher sensitivity; P < 0.01) cases. For accurate diagnosis in suspected brucellosis cases detection, we recommend both ELISA IgM and IgG tests. ELISA IgG and 2-ME tests seem to be promising tools in judging prognosis