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Karnataka, a state in south India, reported its first case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection on March 8, 2020, more than a month after the first case was reported in India. We used a combination of contact tracing and genomic epidemiology to trace the spread of SARS-CoV-2 in the state up until May 21, 2020 (1578 cases). We obtained 91 genomes of SARS-CoV-2 which clustered into seven lineages (Pangolin lineages—A, B, B.1, B.1.80, B.1.1, B.4, and B.6). The lineages in Karnataka were known to be circulating in China, Southeast Asia, Iran, Europe and other parts of India and are likely to have been imported into the state both by international and domestic travel. Our sequences grouped into 17 contact clusters and 24 cases with no known contacts. We found 14 of the 17 contact clusters had a single lineage of the virus, consistent with multiple introductions and most (12/17) were contained within a single district, reflecting local spread. In most of the 17 clusters, the index case (12/17) and spreaders (11/17) were symptomatic. Of the 91 sequences, 47 belonged to the B.6 lineage, including eleven of 24 cases with no known contact, indicating ongoing transmission of this lineage in the state. Genomic epidemiology of SARS-CoV-2 in Karnataka suggests multiple introductions of the virus followed by local transmission in parallel with ongoing viral evolution. This is the first study from India combining genomic data with epidemiological information emphasizing the need for an integrated approach to outbreak response.

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Scrub typhus is associated with outbreaks of acute encephalitis syndrome in Uttar Pradesh, India. A case-control study indicated that children residing, playing, or visiting fields; living with firewood stored indoors; handling cattle fodder; and practicing open defecation were at increased risk for scrub typhus. Communication messages should focus on changing these behaviors.

Background: Acute encephalitis syndrome (AES) surveillance in India has indicated that Japanese encephalitis virus (JEV) accounts for 5-35% of AES cases annually; the etiology remains unknown in the remaining cases. We implemented comprehensive AES surveillance to identify other etiological agents of AES, with emphasis on dengue virus. Methods: Serum and cerebrospinal fluid (CSF) specimens were collected from patients enrolled prospectively in AES surveillance from 2014-2017 at selected sites of three high burden states of India. All samples were initially tested for JEV IgM. Specimens negative for JEV by serology were tested for IgM to scrub typhus, dengue virus (DEN), and West Nile virus; all JEV IgM-negative CSF samples were tested by PCR for S. pneumoniae, N. meningitidis, H. influenzae, herpes simplex virus type 1, enteroviruses and DEN. Results: Of 10,107 AES patients, an etiology could be established in 49.2% of patients including JEV (16%), scrub typhus (16%) and DEN (5.2%) as the top three agents. Amongst the DEN positive cases (359/6892), seven (2%) were positive only for dengue virus RNA: one in serum and six in CSF. Conclusion: Amongst the pathogens identified, dengue accounted for 5% of all AES cases and was one of the three common etiological agents. These results underscore the importance of including dengue virus in routine testing of AES cases.