Avian influenza (AI) H5N1 viruses are zoonotic agents that cause high mortality rates in humans and poultry. In this study, some molecular characterizations and phylogenetic analysis of Hemagglutinin gene of H5N1 isolates seen in our country in 2006 were performed. Thus, it is aimed to determine the pathogenicity levels of those available isolates and whether they have the ability to transmit from person to person and establish the evolutionary relationships to some other viruses circulated in Europe, Asia and Africa. In the scope of the study, seventeen H5N1 isolates that were isolated from various Avian species were used. After the isolates were regenerated and produced in specific pathogen-free (SPF) embryonated chicken eggs, chorioallantoic fluids of the eggs were collected and RNA extraction was made, and the enzyme cleavage and receptor binding site of the hemagglutinin gene was replicated using RT-PCR. After this process, the enzyme cleavage site of the Hemagglutinin genes and the amino acid sequence of the receptor-binding site were determined by the BioEdit program. As a result, it was determined that all the seventeen isolates are High Pathogenic AI viruses. In addition, the sequence analysis of the receptor-binding site indicated that seventeen isolates did not have any mutations in the relevant amino acid positions. Also, our isolates were classified as clade 2.2 and clade 2.2.1 and were closely related to European and Asian isolates. Moreover, it is found that our isolates are not capable of transmitting from person to person; However, due to the virus traits, it has been concluded that the molecular and antigenic characteristics of the virus should be determined in places where the disease occurs since it is still circulating in some parts of the world and can be transported with migratory birds.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide with its different variants. The transmission efficiency of the new variants is much higher than the existing ones. Therefore, developing new preventive measures based on the transmission routes of the virus is needed to limit the spread. The possible transmission routes include direct contact with surfaces contaminated with droplets secreted by patients and airborne viral transmission from person to person. Thermal inactivation is a preventive measure that applies high temperature to objects or fluids, as has been reported previously. However, inactivation data of aerosolized SARS-CoV-2 exposed to heat for a short time at high temperatures are not in the literature yet. We evaluated the inactivation of the aerosolized virus while passing through an electric heater. The virus inactivation test experiments were conducted at two temperatures of the heater’s outlet air, 150±5oC, and 220±5 oC, at an air flow rate of 0.6 m3/h (10 L/min) and heat exposure time of 1.44 s. The loss in viability of the virus at 150 oC and 220 oC was measured as 99.900% and 99.999%, respectively. The results indicate that the high-temperature inactivation of SARS-CoV-2 may potentially reduce aerosolized viral indoors.

The study aims to assess the thermal inactivation of airborne SARS-CoV-2 in a 30 m 3 test room by an electric heater typically used to heat interior spaces during winter, particularly in resource-limited settings. Aerosolized SARS-CoV-2 was delivered to the test room at an ambient temperature of 20 oC and 40% humidity. Two electric heaters with different power and airflow rates were operated in the test room to compare their efficiencies in the inactivation of airborne SARS-CoV-2. The first and second electric heaters had power, airflow rates, and outlet temperature of 1.5 kW, 44 m 3/h, 220 oC, and 3 kW, 324 m 3/h, and 150 oC, respectively. A fan drew the outside air into the heater. Air forced through the heater tunnel absorbed heat energy by interacting with the stainless steel electric tube heating elements perpendicularly located to the airflow direction, increasing outlet air temperature. The first 1.5kW electric heater was operated in the test room for 80 minutes and inactivated 99.00% of the airborne virus. The second, 3 kW electric heater was operated in the test room for 75 minutes and inactivated 99.96% of the airborne virus. The control experiment of each test experiment was conducted without turning the heaters on under otherwise identical conditions.