A Retrospective Study of Clinical and Laboratory Profile of Dengue Fever in Tertiary Care Hospital, Wardha, Maharashtra, India

Dengue disease is caused by dengue virus which is a vector born viral infection. The prevalence of dengue has increased dramatically from past few decades. The clinical symptoms vary from asymptomatic to severe hemorrhagic fever leads to high morbidity and mortality. MethodThis retrospective study was carried out during January 2019 to December 2019. The laboratory test was done by using J Mitra & Co on Day 1 of their visit to the hospital which shows NS1, IgM and IgG reactivity towards dengue fever. The clinical profile information data was collected from patient records. Out of 640 samples 62.18% (398) was positive. The percentage of positive males and females were 60.78%, 64.23% respectively. The highest prevalence of dengue infection was observed more in age group between 31-40 years (81.69%) and least prevalence in age group 71-80 years (36.36%). Most of the patients were positive for NS1Ag121 (30.4%) followed by IgM positive 87 (21.9%) & 59 (14.8%) positive for both IgM and NS1 Ag The highest number of infections was seen during October (75.8%) post monsoon season. All patients had a fever, followed by head ache (82%) and body pains (66.4%), 64.84% stayed in the hospital less than 5 days. In tropical and sub-tropical regions dengue is still a leading public health problem especially during rainy and post monsoon seasons. Both NS1 Ag and IgM detection in early acute phase has potential diagnostic value. So, to reduce mortality there need to initiate community-based cohort studies to predict the pace of dengue spread based on clinical presentation and laboratory findings during epidemics in India. Aedesaegypti is a common vector for transmission of DENV, CHIKV and ZIKV, so there is a need to screen for these infections in endemic areas. Keyword: Dengue, (NS1)Nonstructural Protein I, Immunoglobulin G( IgG), Immunoglobulin M (IgM)


INTRODUCTION
Dengue feveris an acute arboviral infection cause by a dengue virus,there are four distinct serotypes (DENV1, DENV2, DENV3, and DENV4)of this virus transmitted by Aedesaegypti 1 . The clinical symptoms vary from asymptomatic to severe hemorrhagic fever leads to high morbidity and mortality(20%) if left untreated. The prevalence of dengue has increased dramatically from past few decades and now about half of the population of world areis at risk 2,3,4 .Dengue transmission occurs throughout the year in endemic tropical areas; however, in most countries there is a distinct seasonal pattern, with increased transmission usually associated with the monsoon and post monsoon season 5,6 . Lack of specific anti viral drug for the treatment of dengue and had variable clinical presentation which is a very big challenge to the clinicians to prevent the complications and death 7 . So to reduce morbidity out during January 2019 to December 2019, in the department of microbiology, at Jawaharlal Nehru Medical College, Wardha, Maharashtra, India. A total of 640 patients with the clinically suspected cases were included in the study. The laboratory test was done by using a rapid solid phase immuno-chromatographic test(J Mitra & Co. Pvt. Ltd.) on Day 1of their visit to the hospital which shows NS1, IgM and IgG reactivity towards dengue fever. The patient clinical profile such as fever, head ache and length of hospital stay were collected from patient records at MRD (Medical Record Department).

RESULT
A total of 640 patient's were included in the study. ,The distributions of patient demographic results were shown in the and mortality of dengue infection, it is better to understand the clinical profile of disease along with the laboratory parameters of dengue fever. This current retrospective study was carried out to determine, the seasonal distribution, demographic variation with clinical manifestations of all laboratory tested dengue cases.

METHODOLOGY
This retrospective study was carried In the current study highest number of dengue cases were reported in the post-monsoon period similar results were found in study done by Lata R. patel et al. 14 During monsoon period heavy rains leads to stagnation of large amount of water. These are the favourite breeding places for vector

DISCUSSION
According to WHO, in last 5 decades dengue infections has shot up 30 fold, because of its complex patho-physiological, ecological as well as economical problems 8 . In current study majority of patients were males (380 males out of 640 patients)than females, this may due to males are more exposed to mosquitoes in outdoor activity similar findings were reported in Gupta 12 and PadhiS et al. 13 reported that most common affected age group was 11-20 years, the difference may be the study population and Journal of Pure and Applied Microbiology mosquito. This may be the cause for more number of cases in post-monsoon season.
Single stranded RNA virus belonging to genus flavivirus, is responsible for acute illness in dengue. 4 to 10 days was the incubation period for dengue fever. Febrile phase, critical phase and recovery phase are these conditions seen in dengue infection 9 &10 . Overall sero-positivity rate was 62.2% (398/640). In the current study over all NS1 detection was 220 (49.7%) patients were positive, Results were correlating with other study by Anitha Chakravarti 35(39.7%). In dengue infection the role of NS1 Ag for early detection is currently being assess by many investigators, without the requirement of paired sera (Two serum samples taken from a patient usually at 1 week apart)and it circulates uniformly in all serotypes of dengue and there is no cross reaction of dengue NS1 antigen with other flaviviruses [13][14][15] . The NS1 is produced in high concentration in the serum during acute phase (0-6 days) of infection. The sensitivity varies between 85.5 and 95.9% and specificity between 95.0 and 100% using the viral isolation as a reference test 16,17 .
Dengue IgM can be detected within 3-5 days in 50% people after onset of symptoms, and 80% after day 5 and to 99% on day 10they and not detected after 2-3 months. IgM is not specific, they can cross-reaction with other flaviviruses and also with rheumatoid factor 17 . So if the patient sample is reactive for NS1 Ag and IgM antibodies instead of IgM only, that is more specific. At end of the first week of onset symptoms, IgG antibodies will detect and remain life-long in some patients. Detection of NS1 and IgG, IgM and IgG detection indicates the seroconverstion stage of infection. If only IgG Abs detection in serum, it indicates past infection, secondary infection or cross-reaction with other flaviviruses antigen 17 . In the current study fever was present in all the patients (100%), followed by headache and body pains which is similar to the other studies [18][19][20] . Only 16.32% were stayed in the hospital more than 5 days which is similar to the other study carried out by Solanke SN et al. at Jalna 20 . In the current study no mortality was found.

CONCLUSION
In tropical and sub-tropical regions, dengue is still a leading public health problem especially during rainy and post monsoon seasons. An increased urbanization and behavior change in vector is also one cause for increase in dengue cases. Males were most commonly affected. BothNS1 Ag and IgM detection in early acute phase has potential diagnostic value. So, to reduce mortality there need to initiate communitybased cohort studies to predict the pace of dengue spread based on clinical presentation and laboratory findings during epidemics in India. Aedesaegyptiis a common vector for transmission of DENV, CHIKV and ZIKV, so there is a need to screen for these infections in endemic areas.