ABSTRACT
BACKGROUND: Influenza is one of the public health burdens in Nepal and its epidemiology is not clearly understood. The objective of this study was to explore the molecular epidemiology and the antigenic characteristics of the circulating influenza viruses in Nepal. METHODS: A total of 1495 throat swab specimens were collected from January to December, 2014. Real time PCR assay was used for identification of influenza virus types and subtypes. Ten percent of the positive specimens were randomly selected and inoculated onto Madin-Darby Canine Kidney Epithelial cells (MDCK) for influenza virus isolation. All viruses were characterized by the hemagglutination inhibition (HI) assay. RESULTS: Influenza viruses were detected in 421/1495 (28.2%) specimens. Among positive cases, influenza A virus was detected in 301/421 (71.5%); of which 120 (39.9%) were influenza A/H1N1 pdm09 and 181 (60.1%) were influenza A/H3 subtype. Influenza B viruses were detected in 119/421 (28.3%) specimens. Influenza A/H1N1 pdm09, A/H3 and B viruses isolated in Nepal were antigenically similar to the vaccine strain influenza A/California/07/2009(H1N1pdm09), A/Texas/50/2012(H3N2), A/New York/39/2012(H3N2) and B/Massachusetts/2/2012, respectively. CONCLUSIONS: Influenza viruses were reported year-round in different geographical regions of Nepal which was similar to other tropical countries. The circulating influenza virus type and subtypes of Nepal were similar to vaccine candidate virus which could be prevented by currently used influenza vaccine.
Subject(s)
Influenza A virus/classification , Influenza A virus/isolation & purification , Influenza B virus/classification , Influenza B virus/isolation & purification , Pharynx/microbiology , Seasons , Adolescent , Adult , Animals , Child , Child, Preschool , Cross-Sectional Studies , Dogs , Hemagglutination Inhibition Tests , Humans , Infant , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A virus/immunology , Influenza B virus/immunology , Influenza, Human/epidemiology , Madin Darby Canine Kidney Cells , Male , Middle Aged , Molecular Epidemiology , Nepal/epidemiology , Polymerase Chain Reaction , Young AdultABSTRACT
Background Seasonal influenza is one of the increasing public health burdens in Nepal. Objective The objective of this study was to isolate and characterize the influenza virus type and subtypes of Nepal. Method A total of 1536 throat swab specimens were collected from January to December 2012. Total ribonucleic acid was extracted using Qiagen viral nucleic acid extraction kit and polymerase chain reaction assay was performed following the US; CDC Real-time PCR protocol. Ten percent of positive specimens were inoculated onto Madin-Darby Canine Kidney cells. Isolates were characterized by using reference ferret antisera. Result Of the total specimens (n=1536), influenza virus type A was detected in 196 (22%) cases; of which 194 (99%) were influenza A (H1N1) pdm09 and 2 (1 %) were influenza A/H3 subtype. Influenza B was detected in 684 (76.9%) cases. Influenza A (H1N1) pdm09, A/H3 and influenza B virus were antigenically similar to the recommended influenza virus vaccine candidate of the year 2012. Although sporadic cases of influenza were observed throughout the year, peak was observed during July to November. Conclusion Similar to other tropical countries, A (H1N1) pdm09, A/H3 and influenza B viruses were co-circulated in Nepal.
Subject(s)
Betainfluenzavirus/classification , Influenza A virus/classification , Influenza, Human/virology , Animals , Cell Line , Dogs , Humans , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/classification , Betainfluenzavirus/isolation & purification , Nepal , SeasonsABSTRACT
Cholera continued to be a major diarrheal illness in Nepal and antibiotic resistance has appeared as a serious problem in cholera management. The study aimed at analyzing the distribution pattern of the resistotypes (R-types) of Vibrio cholerae in the Kathmandu valley, Nepal. During June 2008 to January 2009, 210 diarrheal specimens received at National Public Health Laboratory from suspected cholera patients were subjected to standard bacteriological investigation including biotyping and serotyping. Antimicrobial susceptibility pattern of V. cholerae isolates was determined by Kirby Bauer disc diffusion method following CLSI guidelines. A total of 57 (27%) V. cholerae isolated were recovered, all of which belonged to 01 Ogawa Biotype EL Tor. Based on antibiogram, V. cholerae isolates in our study revealed three distinct R-types: R-type I, R-type II and R-type III. All three R types showed resistance to furazolidone, nalidixic acid and cotrimoxazole while sensitive to ciprofloxacin and tetracycline. Additional resistance to ampicillin and erythromycin was observed respectively in R-type II and III. Different R-types showed unique month wise variations (P < 0.05). Differentiation of V. cholerae strains into R-types is an important tool. In addition to direct patient management, it may have implication in identifying the source and spread of infection, and understanding the distribution pattern in a particular geographical region.
