Host traits, ownership behaviour and risk factors of SARS-CoV-2 infection in domestic pets in Mexico.

SARS-CoV-2 can infect pets under natural conditions, which raises questions about the risk factors related to the susceptibility of these animals to infection. The status of pet infection by SARS-CoV-2 in Mexico is not well-understood. We aimed to estimate the frequency of positive household cats and dogs to viral RNA and antibodies for SARS-CoV-2 during the second wave of human infections in Mexico, and to recognize the major risk factors related to host and pet ownership behaviour. We evaluated two study groups, cats and dogs from COVID-19-infected/-suspected households (n = 44) and those admitted for veterinary care for any reason at several veterinary hospitals in Puebla City, Mexico (n = 91). Using RT-PCR, we identified the presence of SARS-CoV-2 RNA in swabs of four dogs (18.18%) and zero cats in COVID-19-infected/-suspected households; within this group, 31.82% of dogs and 27.27% of cats were tested IgG ELISA-positive; and neutralizing antibodies were detected in one dog (4.55%) and two cats (9.09%). In the random group (pets evaluated at private clinics and veterinary teaching hospital), 25.00% of dogs and 43.59% of cats were ELISA-positive and only one cat showed neutralizing antibodies (2.56%). Older than 4-year-old, other pets at home, and daily cleaning of pet dish, were each associated with an increase in SARS-CoV-2 infection (p < 0.05). Allowing face lick, sharing bed/food with pets and owner tested positive or suspected COVID-19 were not significant risk factors, but more than 4 h the owner spent away from home during the lockdown for COVID-19 (OR = 0.37, p = 0.01), and outdoor pet food tray (OR = 0.32, p = 0.01) significantly decreased the risks of SARS-CoV-2 infection in pets, suggesting that time the owner spends with their pet is an important risk factor.

Cooling and eutrophication of southern Chilean lakes.

Understanding the impacts of global warming and human-disturbances on lakes is required for implementing management strategies aimed at mitigating the decline of the quality and availability of water for humans. We assessed temporal trends in water parameters, and the contribution of land use to the eutrophication of the largest lakes of central-southern Chile. The mean values of water parameters varied seasonally, with lakes Chapo and Caburgua exhibiting lower pH, temperature, and N/P ratio values. Over the assessed period (19 years), we found a temporal reduction in water conductivity and temperature of the lakes. The concentration of NO3(-)-N, PO4(3-)-P and dissolved oxygen increased in all the lakes, but pH increased in eight out of the ten lakes. The negative temporal trend in temperature was more pronounced as the depth level increased. Lakes whose basins had a higher percentage of forest plantation and urban areas had larger values of Chlorophyll a and pH, as well as, smaller values of dissolved oxygen. Lakes whose basins included larger percentages of native forest had smaller nutrient (NO3(-)-N, PO4(3-)-P) concentrations. Our findings suggest that decreased rainfall in central-southern Chile due to climate change may cause a decrease of particulate material that is carried by tributaries into the lakes. The observed temporal decrease in temperature, especially at the deeper levels, may be explained by the rapid melting of glaciers. Although the studied lakes are classified as oligotrophic, deforestation and expansion of urban areas around the lakes have led to increased nutrient input, thus accelerating their eutrophication.