No abstract

Dengue fever is a fast spreading mosquito borne viral disease transmitted by Aedes mosquitoes. The abundance and the transmission potential of Aedes mosquitoes are influenced by climatic factors. An investigation was carried out in Thiruvananthapuram district, Kerala to study the correlation between rainfall and prevalence of dengue infection during 2015-2019 . Dengue data (2015-2019 were collected from Directorate of Health Services, Thiruvananthapuram and the rainfall data were derived from Indian Meteorological Department, Thiruvananthapuram. The correlation between the rainfall and the prevalence of dengue was assessed by regression analysis. Dengue cases usually follow a seasonal pattern, with most of the cases reported during the monsoon season. Rainfall were positively associated with the number of dengue cases and highly significant correlation was found between dengue cases and rainfall. The regression equation for prevalence of dengue (y) versus rainfall (x) is y = 1.28 x + 31.03 (r = 0.875, p < 0.001). The study indicated that the prevalence of dengue infection in Thiruvananthapuram district may depend on rainfall. Therefore, intensified surveillance and control of mosquito during the period with heavy rainfall is recommended.

Among arthropod vectors, mosquitoes are the most important vector that transmit diseases such as Malaria, Filariasis, Chikungunya (CG), Dengue Fever (DF), Yellow Fever, Japanese Encephalitis (JE) etc. Forest fringe associated rubber plantation areas are more prone to the spread of zoonotic diseases to rural and urban areas. In view of this, a study was conducted to assess the species composition and density of mosquitoes in the urban and rural areas of rubber plantation sectors of Kottayam district. Two villages from forest fringe associated rubber plantation areas and two wards from urban areas of Kottayam district were selected for the study. Immature and adult mosquitoes were collected based on WHO standard procedures. A total of 14 mosquito species were recorded in the present study in which five species belong to the Aedeine group. Aedes albopictus was the predominant vector species in the study areas. Aedes albopictus was found to be abundant in the urban areas while Armigeres subalbatus was recorded as the prevalent species in the rural areas. Per man hour density of mosquitoes were found maximum during June and July and density of Aedes albopictus found maximum during the month of May. Water storage containers were observed to be the major breeding habitat for Ae. albopictus in urban areas and discarded or unused rubber latex collection containers were found to be the main breeding source for Ae albopictus in rural areas. Since Aedes transmitted diseases such as dengue and chikungunya are being reported in the study area entomological surveillance and its significance can be used to halt the outbreak as shown in this study.

Nanoparticles are molecules in the range of 1 nm to 100 nm and they can be synthesized by physical, chemical and biological methods. Green synthesis involves the production of nanoparticles from bacteria, fungi, algae, plants and plant extracts. Plant extracts with their chemical constituents can capture the target metals from their salt solution and transform the metal particles into nanoparticles with the cellular catalysts. The present study focuses on the green synthesis of silver nanoparticles using the liquid endosperm of coconut, the coconut water (Cocos nucifera), Liquid endosperm of palm fruit (Borassus flabellifer) and coconut Toddy as the reducing agent. The bio-reduction of aqueous silver ions by coconut water is identified by its colour change. During the synthesis of silver nanoparticles, the colour of the solution changed from milky white to brown. The characterization of synthesized AgNPs (Silver Nanoparticles) was done by Fourier Transform Infrared Spectroscopy and UV-Vis Spectroscopy. The peaks obtained at 250 and 350 nm confirmed the presence of synthesized Silver Nanoparticles. The antibacterial activity of the synthesized nanoparticles was studied on Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes using disc diffusion method. The recent approach of green synthesis is quite impressive due to its eco- friendly, economical, feasible and non- toxic nature.

We report Glyptotermes ceylonicus (Holmgren, 1911), an endemic Sri Lankan termite, for the first time from India. Glyptotermes show a high degree of endemism throughout the world. Record of this species from the current location indicates a wide distribution of this species in southern India, in the past, before the complete separation of Sri Lanka from India. The current distribution of Glyptotermes ceylonicus is also an example of discontinuous distribution. Pictorial illustrations of the morphologically important parts and revised key for the Indian species are provided.