ABSTRACT
Background and Objectives: Influenza virus is a typical human pathogen causing serious respiratory illness resulting in significant mortality throughout the globe. Andhra Pradesh witnessed the first case of influenza A H1N1 in India from Hyderabad (now in Telangana) on May 16, 2009. In the recent past, Andhra Pradesh witnessed exponential increase in the number of confirmed cases of influenza infection. In this study, we present the salient features of the recent outbreak of influenza during 2017�18 in the state of Andhra Pradesh, first of its kind after the division of the state. Materials and Methods: Clinically, suspected cases of influenza-like illness received in the Virus Research and Diagnostic Laboratory, Department of Microbiology, Sri Venkateswara Institute of Medical Sciences (SVIMS), Tirupati, from January 2017 to May 2018 were included in the study. The samples were tested for influenza A, influenza A (H1N1) pdm09, influenza A (H3N2), influenza B, influenza B/Yamagata and influenza B/Victoria. Results: A total of 1286 samples were received for testing. The positive samples were influenza A unsubtypable (109), influenza A (H1N1) pdm09 (356), influenza A (H3N2) (38) and influenza B (19; Victoria - 2, Yamagata - 17). There was no significant difference in positivity between genders with 260 (49.81%) females and 262 (50.19%) males being positive. Conclusion: The outbreak started in the late monsoon (January) of 2017 and had two peaks; one in summer months and another in winter months. Influenza B virus was reported from December 2017 to May 2018. Age groups ?5 years and 6� years had higher positivity as compared to other age groups. Regular surveillance programmes are required for assessing the trends of influenza infections due to various subtypes and to plan timely and adequate steps for preventing the spread to larger vulnerable population.
ABSTRACT
Background: Dengue is one of the most important mosquito-borne viral diseases in the world. The emergence and spread of four dengue viruses (DENVs) (serotypes) represent a global pandemic. The four distinct serotypes are, namely, DENV-1, DENV-2, DENV-3 and DENV-4. Very few dengue serotyping studies have been reported from Andhra Pradesh. In this context, the present study focuses on the circulating serotypes of dengue in South-Eastern Andhra Pradesh. Methodology: Study was done at Sri Venkateswara Institute of Medical Sciences, a teaching hospital in Tirupati, Andhra Pradesh. Acute phase dengue serum samples were collected and tested for NS1 antigen and anti-human IgM antibodies by enzyme-linked immunosorbent assay (ELISA). NS1-positive samples were further serotyped by reverse transcriptase real-time polymerase chain reaction (rRT-PCR). Results: A total of 398 serum samples were received from clinically suspected dengue fever cases. Of these, 150 (37.7%) samples were positive for NS1 and/or IgM ELISA. The 96 NS1 antigen-positive samples were further processed for serotyping, of which 36 were negative by rRT-PCR. DENV-2 (41%) was the predominant serotype, followed by DENV-4 (37%), DENV-3 (12%) and DENV-1 (10%) in descending order. Conclusion: This study reports the all four dengue serotypes' co-circulation. This is the first report from South Eastern Andhra Pradesh. Amongst four, DENV-2 was predominant followed by DENV-4. The information of predominant serotypes can guide in forecasting dengue outbreaks and improving control measures of vectors thus may be helpful in the prevention of outbreaks.