Molecular detection of dengue virus serotypes from clinical samples prevalent in and around Coimbatore

Thenmozhi, Palanisamy (2018) Molecular detection of dengue virus serotypes from clinical samples prevalent in and around Coimbatore. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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INTRODUCTION: Dengue fever is a mosquito-borne tropical disease caused by the Dengue virus. Dengue fever virus (DENV) is an RNA virus of the family Flaviviridae; genus Flavivirus. Dengue is spread by Aedes aegypti and Ae.albopictus.DENV- There are five closely related but serologically distinct Dengue viruses, called 1, DENV-2, DENV-3, DENV-4 and DENV-5 of the genus Flavivirus. AIM OF THE STUDY: To identify the Dengue serotypes using molecular methods and its association with disease severity. OBJECTIVES: To find out the proportion of Dengue infection in fever patients in hospital. To classify primary and secondary Dengue. To find out the serotypes prevalent here using multiplex-nested PCR and severity of the disease with serotypes. METHODOLOGY: NS1, IgM and IgG ELISA was done for 150 cases.NS1 positive cases were subjected to RNA extraction-22 cases (>50 NS1 Ag units) out of 118 cases. Extracted RNA was subjected to PCR:15 cases PCR positive out of 22 cases. RESULTS: The total number of patients with suspected Dengue in our hospital from August 2016 to August 2017 was 6557, out of which 70.81% (4643) were seropositive. A total of 150 consecutive serum samples were selected from August 2016 to August 2017.Out of 150 samples, seropositivity was 78.67% (118) with 55.9% (66) primary Dengue, most of them had < 5days of fever and 44.1% (52) secondary Dengue infections. IgM 9.3% (11), NS1+IgM 9.3% (11), NS1+IgM+IgG 9.3% (11), IgM+IgG 33.99% (40) and only IgG 0.85% (1). NS1 antigen positivity in 55.93% (66) out of 118 patients, Nine patients showed NS1 positivity (7.63%) on 9th day of fever. Males affected more, Commonly affected age group-11 to 20 years, peak cases in July and August (2017), common clinical symptom was high grade fever with joint pain and commonly observed significant laboratory parameters-Thrombocytopenia & Elevated liver enzymes. The most common serotype identified was DENV-3followed by DENV-2 among which Co-infection with DENV 2 & 3 was seen in 6 cases, followed by DENV-3 alone in 5 cases and DENV-2 alone in 4 cases. DENV-2&3 coinfection (50%) was associated to DHF and DSS, Dengue with warning signs 33.33% and Dengue without warning signs16.66%. DENV-2 & 3 coinfection was primary Dengue (83.33) and secondary Dengue (16.67). DENV-3 and DENV-2 infection was associated with Dengue without warning signs.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Dengue ; NS1 ; IgM ; IgG ; Dengue RNA extraction ; Molecular serotyping.
Subjects: MEDICAL > Microbiology
Depositing User: Subramani R
Date Deposited: 13 Jul 2018 01:59
Last Modified: 13 Jul 2018 01:59

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