PCR has recently been studied as a promising tool for monitoring the progress of efforts to eliminate lymphatic filariasis. PCR can be used to test concurrently at least 30 pools, with as many as 40 mosquitoes in each pool, for the presence of filarial larvae. The SspI PCR assay for the detection of Wuchereria bancrofti DNA in pools of mosquitoes has been used since 1994 in a variety of laboratories worldwide. During that time, the original assay has been modified in these different laboratories and no standardized assay currently exists. In an effort to standardize and improve the assay, a meeting was held on 15-16 November 2001, at Emory University in Atlanta, with representatives from most of the laboratories currently using the assay. The first round of testing was designed to test the four most promising methods for DNA extraction from pools of mosquitoes. Two of the four methods stood out as clearly the best and these will be now optimised and evaluated in two further rounds of testing.

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Scrub typhus, caused by the proteobacterium, Orientia tsutsugamushi, is re-emerging in several regions of Asia, particularly in India. Severity of infection and clinical presentations are known to vary with the infecting prototype/ genotype. Hence genotypic characterization and distribution of various genotypes is of clinical and epidemiological importance. One hundred and forty five suspected scrub typhus cases, reporting to a tertiary care centre in Puducherry, India were investigated for O. tsutsugamushi specific IgM antibodies by ELISA out of which, 135 (93%) were positive. Most cases occurred post-monsoon, peaking in September, and there was a preponderance in young adults. Forty samples tested positive by Nested PCR based on 56kDa gene of O. tsutsugamushi and amplicons from PCR positive samples were sequenced. Phylogenetic tree constructed using 35 sequences (from nt 20 to nt 130) obtained in the study, along with those retrieved from NCBI site, formed two major branches; one comprising 15 sequences from this study, which aligned with Karp genotype, and the other containing 6 sequences which aligned with a sequence from Vellore, India. The second major branch had 12 sequences, which formed an independent group from the Gilliam prototype. Analysis of association of clinical manifestations with genotypes obtained in the present study showed that the sequences that formed an independent group, were associated with a wide spectrum of clinical manifestations involving multiple organs and more severe manifestations like ARDS and hypotension. The sequences, which branched with Karp prototype were associated with hepatitis, meningitis and Multi-organ disorder syndrome (MODS). The present study thus indicated that different genotypes of O. tsutsugamushi occur in southern regions of India, which were associated with various clinical manifestations. Studies on the occurrence of genotypes will help in development of diagnostic methods and vaccines to curtail the infection.

Background In wake of the global health emergency declared by the World Health Organization (WHO) during 2016, on the outbreak of ZIKA pandemic, Indian Council of Medical Research (ICMR) carried out countrywide vector surveillance for ZIKA and DENGUE viruses (ZIKV & DENV) in India, as a preparedness measure. Methods The study incorporated high-risk zones distributed to 49 Districts in 14 states/ Union Territories (UT) of India during 2016-2019. Seven ICMR Institutions undertook the study, following a uniform Standard Operating Protocol. Aedes specimens sampled on weekly intervals were processed by multiplex Reverse transcriptase PCR for ZIKV/DENV and Real time RT-PCR of ZIKV, among few samples distributed to all the Districts. Results Altogether, 79492 specimens of Aedes mosquitoes in 6492 pools were processed for both ZIKV and DENV infections. Among these, three and 63 pools respectively were found positive for ZIKV and DENV. ZIKV infections were recorded from Aedes aegypti sampled during 2018 sporadic ZIKA outbreak in Jaipur, Rajasthan, which belonged to the Asian lineage, already circulating in the Country. Both Ae. aegypti and Aedes albopictus were found infected with DENV and were distributed to ten states/ UTs. Both male and female specimens of Ae. albopictus recorded DENV infections indicating trans-ovarial transmission of DENV in the species. Conclusion This national vector surveillance study evinced no active transmission of the “American lineage - pandemic ZIKA virus” in India during 2016-2019, although Asian lineage of the virus already circulating in the Country was detected from Ae. aegypti from Jaipur, Rajasthan.

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