Role of Molecular methods in the diagnosis of Dengue

Sangeetha, N (2012) Role of Molecular methods in the diagnosis of Dengue. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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Between June 2010 to May 2011, a total of 1,727 serum samples from equal number of patients, suspected dengue fever patients were tested for IgM and IgG antibodies using dengue capture ELISA. • Seven hundred and six (41%) of patients were found to have dengue antibodies and 29.60% were primary dengue and 70.39% were secondary dengue. • Males were affected more than females in this study. Male-tofemale ratio in our study group was 1.2:0.97. • Commonly affected age group by dengue viral infections were 21-30 yrs (28.36%) followed by 31-40 yrs (21%). • More number of cases was observed during November and December (36%) corresponds to monsoon and post monsoon period. • NS1 antigen positivity was found in 39(50%) out of 78 patients with ≤ 9 fever days. • Seventeen(77%) out of 22 primary dengue and 20 (41%) out of 49 secondary dengue patients had NS1 antigen positivity NS1 antigen detection was more in primary cases than secondary dengue cases. • NS1 antigen was also positive in 2 out of 7 (29%) antibody negative patients. • NS1 antigen yield was more when samples were tested in the earlier phase of fever. • According to the WHO guidelines, 39 dengue NS1 antigen positive cases in the present study were categorized into dengue fever 30 (77%), dengue hemorrhagic fever 6 (15%) and dengue shock syndrome 3 (8%). • The most Common clinical feature in NS1 antigen and sero positive febrile patients was thrombocytopenia (85%) followed by joint pain (54%). • Dengue PCR was positive in 3 out of 30 patients with 3-6 fever days. The PCR positive samples were also positive for NS1 antigen. • The PCR detected dengue virus belongs to serotype-2. CONCLUSION: Early diagnosis of dengue fever leads to better management, less morbidity and mortality. There are more secondary dengue infections than primary dengue infections indicating circulation of more than one serotype. It was more common in males and in the age group 21-30yrs and the disease was found to be more common during November and December correlating with high mosquito breeding.NS1 antigen and PCR will be useful when samples were collected very early during the course of the fever. The prevalent serotype of dengue in this area was found to be dengue serotype-2.

Item Type: Thesis (Masters)
Additional Information: Reg.No.20091302
Uncontrolled Keywords: Molecular methods, diagnosis, Dengue.
Subjects: MEDICAL > Microbiology
Depositing User: Subramani R
Date Deposited: 14 Sep 2020 03:16
Last Modified: 14 Sep 2020 03:16

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