Chikungunya fever is reported in India after 32 years. Immunoglobulin M antibodies and virus isolation confirmed the cause. Phylogenic analysis based on partial sequences of NS4 and E1 genes showed that all earlier isolates (1963–1973) were Asian genotype, whereas the current and Yawat (2000) isolates were African genotype.

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Chikungunya fever is an arthropod-borne disease caused by chikungunya virus (CHIKV) belonging to genus Alphavirus , family Togaviridae . CHIKV has re-emerged in India, Indian Ocean Islands, and South East Asia in an explosive outbreak affecting ~6 million people in 2005-06. 1 During the resurgence, the virus caused severe morbidity and clinical complications that were hitherto unknown of CHIKV.2 Neurological, ophthalmological, renal, and cutaneous involvement was more evident during the recent outbreak in addition to encephalitis/ encephalopathy.1-3 The CHIKV-associated mortality was very high in La Reunion Island and India and accounted for several thousand deaths. 4 The virus is transmitted to humans by the bite of infected Aedes aegypti mosquitoes, the principal vector of chikungunya in urban areas and Ae. albopictus mosquitoes in peri-urban areas.2 The recent mutation in the CHIKV genome has helped the virus to adapt to the new vector, Aedes albopictus for rapid dissemination and transmission.5 Vector control is the only means to break virus transmission as no effective therapies or vaccines are in place for the virus. Proactive surveillance of vector species for detection of CHIKV is an accepted mode of surveillance where wild-caught mosquitoes are screened routinely as part of the virus detection program. However, a major concern was the maintenance of a cold chain during transport of mosquitoes from field to laboratory in many tropical countries. The recent report of dengue virus detection in dried Ae. aegypti mosquitoes by reverse transcriptase-polymerase chain reaction (RT-PCR) 6 have prompted us to take up a study in the same direction. In this communication, we report the methodology of mosquito storage and the persistence of CHIKV RNA in experimentally infected, dried, and stored Ae. aegypti mosquitoes using RT-PCR.In this study, laboratory-reared 2-to 3-day-old adult female Ae. aegypti mosquitoes ( N = 150) were inoculated intrathoracically with ~0.2 μL of CHIKV (strain no. 061573) suspension as described earlier. 7 In brief, mosquitoes were immobilized by keeping them over wet ice for 5-10 min and inoculated with virus suspension in the membranous area of the mesothorax between the spiracle and sternoplural region under a dissecting binocular microscope. Inoculation was carried out using a calibrated capillary needle and syringe plunger and the whole procedure was conducted inside a mosquito proof enclosure. After inoculation, the mosquitoes were placed in plastic mosquito holding jars, provided a diet of 10% glucose (cotton swab soaked in glucose solution), and incubated at 28°C with 80 ± 5% relative humidity (RH). On Day 6 post-infection (PI), 10 mosquitoes were removed randomly and tested for the presence of CHIKV antigen in the head by immunofluorescence assay (IFA) as described by Dhanda and Ilkal.8 After confirmation of infectivity in all the tested specimens, the rest of the females were frozen at -80°C for 30 min, removed from the freezer, stuck to sticky adhesive tape (Johnson and Johnso...

Introduction: Many SARS-CoV-2 variants of concern (VOC) have been reported recently that were linked to increased transmission. In our earlier study using VOC 202012/01 (U.K. variant) and D614G variant in the hamster model, we observed higher viral RNA shedding through nasal wash in the case of U.K. variant with lower pathogenicity in lung. In this study, we have studied transmission of these two variants by direct contact, aerosol, and fomite routes in Syrian hamsters and compared the viral load and body weight changes in hamsters exposed by both variants to understand the transmission efficiency. Methods: Nasal, throat, and rectal swabs were collected sequentially to assess viral load till 14 days. Results: Transmission could be established by direct, aerosol, and fomite contact in Syrian hamsters. Body weight loss or viral load in the contact animals exposed did not show any statistical significance. Conclusion:The study demonstrated comparable transmission of both U.K. and D614G variants of SARS-CoV-2 in Syrian hamsters in the given conditions. Provided these data, it seems that all the routes of exposure are effective leading to higher transmission.