Biology subjects

Gonzales, J. L.

Publications and source records attributed to Gonzales, J. L..

4 recordsLinked to original sources

bioRxiv2023

Highly pathogenic avian influenza A H5 virus outbreaks in broiler farms in the Netherlands. Clinical signs, transmission and identification of reporting thresholds.

BackgroundFor a successful control of highly pathogenic avian influenza virus (HPAIV) epidemics in poultry, early detection is key and it is mostly dependent on the farmers prompt identification of disease and reporting suspicions. The latter could be further improved by providing references to farmers for triggering suspicions. MethodsHere we report observations on clinical signs of HPAIV H5N1 and H5N8 infected broiler farms in the Netherlands and analyze their daily mortality and feed and water intake data in order to identify thresholds for reporting suspicions. In addition, mortality data was used to characterize the transmissibility of these viruses, which could help estimate how fast infection spreads within the flock and when infection was likely introduced. ResultsThe most frequently observed clinical signs in affected flocks were sudden increase in mortality, cyanosis of wattles comb and/or legs and hemorrhagic conjunctiva. Analysis of mortality data indicate that daily mortality higher than 0.17% is an effective threshold for reporting a HPAIV-suspicion. Reliable thresholds for food or water intake could not be stablished. The estimated within-flock transmission rates ranged from 1.1 to 2.0 infections caused by one infectious broiler chicken per day. ConclusionsWe identified effective mortality thresholds for reporting suspicions of HPAIV infections. The estimated transmission rates appear to indicate a slow progression of a H5 HPAIV outbreak in affected broiler flocks. The information here provided can be used to improve syndromic surveillance and guide outbreak response.

microbiology↗

bioRxiv2022

Highly pathogenic avian influenza H5N1 virus infections in wild red foxes (Vulpes vulpes) show neurotropism and adaptive virus mutations

During the 2020-2022 epizootic of highly pathogenic avian influenza virus (HPAI) several infections of mammalian species were reported in Europe. In the Netherlands, HPAI H5N1 virus infections were detected in three wild red foxes (Vulpes vulpes) that were submitted with neurological symptoms between December 2021 and February 2022. Histopathological analysis demonstrated the virus was mainly present in the brain, with limited or no detection in the respiratory tract and other organs. Phylogenetic analysis showed the three fox viruses were not closely related, but were related to HPAI H5N1 clade 2.3.4.4b viruses found in wild birds. In addition, limited virus shedding was detected suggesting the virus was not transmitted between the foxes. Genetic analysis demonstrated the presence of mammalian adaptation E627K in the polymerase basic two (PB2) protein of the two fox viruses. In both foxes the avian (PB2-627E) and the mammalian (PB2-627K) variant were present as a mixture in the virus population, which suggests the mutation emerged in these specific animals. The two variant viruses were isolated and virus replication and passaging experiments were performed. These experiments showed mutation PB2-627K increases replication of the virus in mammalian cell lines compared to the chicken cell line, and at the lower temperatures of the mammalian upper respiratory tract. This study showed the HPAI H5N1 virus is capable of adaptation to mammals, however more adaptive mutations are required to allow efficient transmission between mammals. Therefore, surveillance in mammals should be expanded to closely monitor the emergence of zoonotic mutations for pandemic preparedness. IMPORTANCEHighly pathogenic avian influenza (HPAI) viruses caused high mortality amongst wild birds in 2021-2022 in the Netherlands. Recently three wild foxes were found to be infected with HPAI H5N1 viruses, likely by feeding on infected birds. Although HPAI is a respiratory virus, in these foxes the viruses were mostly detected in the brain. Two viruses isolated from the foxes contained a mutation that is associated with adaptation to mammals. We show the mutant virus replicates better in mammalian cells than in avian cells, and at the lower body temperature of mammals. More mutations are required before viruses can transmit between mammals, or can be transmitted to humans. However, the infections in mammalian species should be closely monitored to swiftly detect mutations that may increase the zoonotic potential of the HPAI H5N1 viruses as these may threaten public health.

microbiology↗

bioRxiv2022

Efficient direct and limited environmental transmission of SARS-CoV-2 lineage B.1.22 in domestic cats

Susceptibility of domestic cats for infection with SARS-CoV-2 has been demonstrated by several experimental studies and field observations. We performed an extensive study to further characterize transmission of SARS-CoV-2 between cats, both by direct contact as well as by indirect contact. To that end, we estimated the transmission rate parameter and the decay parameter for infectivity in the environment. Using four groups of pair-transmission experiment, all donor (inoculated) cats became infected, shed virus and seroconverted, while three out of four direct contact cats got infected, shed virus and two of those seroconverted. One out of eight cats exposed to a SARS-CoV-2-contaminated environment became infected but did not seroconvert. Statistical analysis of the transmission data gives a reproduction number R0 of 2.18 (95% CI: (0.92-4.08), a transmission rate parameter {beta} of 0.23 day-1 (95% CI: 0.06-0.54), and a virus decay rate parameter of 2.73 day-1 (95% CI: 0.77-15.82). These data indicate that transmission between cats can be sustained (R0>1), however, infectiousness of a contaminated environment decays rapidly (mean duration of infectiousness 1/2.73 days). Infections of cats via exposure to a SARS-CoV-2-contaminated environment cannot be excluded if cats are exposed shortly after contamination.

microbiology↗

bioRxiv2021

The SARS-CoV-2 reproduction number R0 in cats

Domestic cats are susceptible to SARS-CoV-2 virus infection and given that they are in close contact with people, assessing the potential risk cats represent for the transmission and maintenance of SARS-CoV-2 is important. Assessing this risk implies quantifying transmission from humans-to-cats, from cats-to-cats and from cats-to-humans. Here we quantified the risk of cat-to-cat transmission by reviewing published literature describing transmission either experimentally or under natural conditions in infected households. Data from these studies were collated to quantify the SARS-CoV-2 reproduction number R0 among cats. The estimated R0 was significantly higher than 1, hence cats could play a role in the transmission and maintenance of SARS-CoV-2. Questions that remain to be addressed are the risk of transmission from humans-to-cats and cats-to-humans. Further data on household transmission and data on virus levels in both the environment around infected cats and their exhaled air could be a step towards assessing these risks.

microbiology↗