Dengue Outbreak Update in India: 2022

Dengue is an emerging illness in India, where it is endemic in some areas and sometimes causes yearly epidemics. Each dengue outbreak starts with high death and morbidity, which has a significant socioeconomic impact. As of September 30, 2022, India had 63,280 dengue cases, according to information provided by the National Centre for Vector Borne Diseases Control. North India is most severely impacted by each outbreak. In Uttar Pradesh, the state with the most population in India, there have been 2060 confirmed cases of dengue and 1 mortality till September 2022 reported. Patients are being reported from semi-urban, rural, and urban areas. It is essential to properly monitor disease cases through disease surveillance in order to ensure prompt case management if dengue outbreak control is to be achieved. An efficient diagnostic approach for early diagnosis is urgently required to reduce the severity of the sickness, the length of the hospital stay, and clinical consequences.

Outbreaks of dengue in Central India in 2016: Clinical, laboratory & epidemiological study

Background & objectives: Dengue virus (DENV) causes outbreaks and sporadic cases in tropical and subtropical countries. Documenting intricacies of DEN outbreaks is important for future interventions. The objective of this study was to report clinical, laboratory and epidemiological features of DEN outbreaks reported in different districts of Central India in 2016. Methods: In 2016, outbreaks (n=4) suspected of DEN were investigated by rapid response team. Door-to-door fever and entomological surveys were conducted. Blood samples were collected and tested using NS1 or IgM ELISA; real-time reverse transcription-polymerase chain reaction was done to identify serotypes of DEN virus (DENV). NS1-positive samples were tested for the presence of IgG by ELISA. Clinical and demographic data were collected and analyzed. Results: Outbreaks occurred in both urban and rural areas in monsoon season and Aedes aegypti was identified as the vector. Fever, chills, headache and myalgia were the major symptoms; no fatality was recorded. Of the 268 DEN suspects, 135 (50.4%) were found serologically positive. DEN positivity was higher (n=75; 55.56%) among males and in the age group of 16-45 yr (n=78; 57.8%). DENV 3 followed by DENV 2 were detected as the major responsible serotypes. High attack rates (up to 38/1000) and low cumulative IgG prevalence (14.9%) were recorded in rural areas. Interpretation & conclusions: Our study showed that DENV 3 was the major serotype responsible for outbreaks that occurred in monsoon. High attack rates and lower number of secondary infections in rural areas indicated that DENV is emerging in rural parts of Central India. Early diagnosis at local level and timely intervention by mosquito control activities are needed to avoid such outbreaks in future.

Measuring Aedes & Breteau Indices in Determining Dengue Outbreak; A Study in Kota Tinggi

@#Introduction Dengue fever, the most known vector-borne disease in the tropical and subtropical regions has become major public health concern worldwide. Rapid urbanization, increased population movement and poor public hygienic lifestyle contributed to the proliferated of high incidence of dengue fever in urban and semi urban areas. With the increasing trend of dengue cases and deaths, methods of dengue surveillance should be reevaluated in predicting dengue outbreak. Methods This study aimed to determine association between Aedes Index and Breteau Index with dengue outbreak in the district of Kota Tinggi, Johor. Results Total of 593 dengue cases in 2015 collected from Kota Tinggi Health Office. The study found that there were significant association between Aedes Index and Breteau Index with localities (p< 0.01) significant association between dengue outbreak incidence and low transmission of aedes indices (p<0.01). However these indices reported low sensitivity and specificity in predicting dengue outbreak in this area. Conclusions As dengue disease remains a major endemic in Malaysia, better surveillance index should be reconsider as the main surveillance for dengue disease.

Outbreak of dengue virus serotype-2 (DENV-2) of Cambodian origin in Manipur, India - Association with meteorological factors.

Background & objectives: Dengue is a major health problem in many parts of India and its neighbouring countries. Dengue cases have not been reported from Manipur, a northeastern State of India till 2007. But, the sudden outbreak of fever with febrile illness during 2007 and 2008, suspected to be dengue/dengue haemorrhagic fever was investigated to detect the causative agent. Potential impact of climatic variables on dengue transmission has been documented and hence the association between climatic factors, entomological parameters and dengue cases was also analysed. Methods: Forty two and 16 blood samples were collected from patients suspected to have dengue infection in the year 2007 and 2008, respectively. Viral RNA was extracted from serum samples and subjected to multiplex one step RT-PCR assay. Dengue specific amplicons were sequenced and phylogenetic analysis was carried out. Multiyear trend analysis and ‘t’ test were performed for the comparison of different meteorological variables between the years 2000-2004 and 2005-2008. Results: The aetiological agent was found to be DENV-2 and the phylogenetic analysis showed that the isolate was similar to that of Cambodian isolate. There was a significant difference in minimum temperature (P<0.05), Relative humidity - morning hours (P<0.001), relative humanity - afternoon hours (P<0.01) and cumulative precipitation (P< 0.05) between the years 2000-2004 and 2005-2008. Interpretation & conclusions: The sudden outbreak of dengue fever in Manipur State occurred was possibly due to the increased temperature, relative humidity and decrease in cumulative precipitation. These climatic factors would have contributed to the Aedes mosquito abundance and increased virus transmission. Proper diseases surveillance system integrated with meteorological warning system and management of vector breeding sites will prevent such outbreaks in future.

The 2006 Dengue Outbreak in Delhi, India.

Dengue is a worldwide condition spread throughout the tropical and subtropical zones between 30 degrees north and 40 degrees south. It is endemic in South East Asia, the pacific, East and West Africa, the Caribbean and the Americas. Dengue outbreaks are occurring almost every three yearly in Delhi for the last 12 years. The latest outbreak was in the year 2006, which started late in August, peaked in the month of October and lasted till late November. We describe here the clinical, hematological and biochemical data of 70 patients of dengue fever diagnosed as per WHO criteria in Lok Nayak Hospital, New Delhi during this outbreak. Hematological parameters were estimated by automated counter and dengue serology was done by capture ELISA technique. The results displayed widespread effect of dengue fever on hematological and biochemical profile. Some of our patients also had atypical dengue manifestations. These results suggest that dengue fever is a major public health problem which can lead to significant morbidity and can even be fatal at times. All efforts should be made to prevent it.