Interspecies Jumping of Bat Coronaviruses

In the last two decades, several coronavirus (CoV) interspecies jumping events have occurred between bats and other animals/humans, leading to major epidemics/pandemics and high fatalities. The SARS epidemic in 2002/2003 had a ~10% fatality. The discovery of SARS-related CoVs in horseshoe bats and civets and genomic studies have confirmed bat-to-civet-to-human transmission. The MERS epidemic that emerged in 2012 had a ~35% mortality, with dromedaries as the reservoir. Although CoVs with the same genome organization (e.g., Tylonycteris BatCoV HKU4 and Pipistrellus BatCoV HKU5) were also detected in bats, there is still a phylogenetic gap between these bat CoVs and MERS-CoV. In 2016, 10 years after the discovery of Rhinolophus BatCoV HKU2 in Chinese horseshoe bats, fatal swine disease outbreaks caused by this virus were reported in southern China. In late 2019, an outbreak of pneumonia emerged in Wuhan, China, and rapidly spread globally, leading to >4,000,000 fatalities so far. Although the genome of SARS-CoV-2 is highly similar to that of SARS-CoV, patient zero and the original source of the pandemic are still unknown. To protect humans from future public health threats, measures should be taken to monitor and reduce the chance of interspecies jumping events, either occurring naturally or through recombineering experiments.

First detection of porcine circovirus type 3 in Ukraine

To date, there is no information regarding the occurrence of porcine circovirus type 3 (PCV-3) in pigs in Ukraine. Aim. The aim of this work was to study the probable occurrence of the little-studied PCV-3 in pigs with different health status in Dnipropetrovsk, Donetsk, Kyiv, and Kharkiv regions of Ukraine. Methods. Blood, semen, liver, spleen, lung samples and nasal swabs of sows and boars of different ages and with different health status, belonging to farms from Dnipro, Donetsk, Kyiv, and Kharkiv regions of Ukraine, were used for the study. PCV-3 genomic material was detected by the standard polymerase chain reaction using specific primers, flanking a fragment of the rep gene of the virus with the length of 418 bp. To visualize the amplicons, horizontal gel electrophoresis was used and ethidium bromide staining after electrophoresis, followed by photographing the gels using Image Lab 5.2.1 software. Results. DNA of PCV-3 was found in two liver samples and four nasal swabs in two different farms, obtained from clinically healthy pigs, which suggests the possibility of the circulation of this infectious agent at the subclinical level of infection at the farm under investigation. No PCV-3 coinfection with the causative agents of porcine reproductive and respiratory syndrome (PRRS), Aujeszky’s disease, PCV-2, and mycoplasmas was found at this farm. Conclusions. Porcine circovirus type 3 (PCV-3) – (a little-studied causative agent of swine disease) was detected in 6 out of 61 samples, originating from two farms in the Kyiv and Kharkiv regions, obtained from clinically healthy animals) for the first time in Ukraine. This indicates possible circulation of the pathogen among pig farms in Ukraine and demonstrates the need to create and implement a target risk analysis, an extensive survey, as well as to develop control measures of the disease spreading (both organizational and technical preventive). Molecular genetic surveying and subsequent monitoring of PCV-3 among domestic and wild animals, which can cross the borders, will give a possibility to determine the risks of its spreading and related economic and epidemiological consequences. The whole-genome DNA sequencing of the detected virus isolates is planned to determine the relation of Ukrainian strains of the virus to other strains circulating in Europe and other parts of the world. Better understanding the risks, epidemiology and pathology, associated with this new virus for the Ukrainian pig breeding industry, will help to prevent and control its further spread and harmful effects.

Modeling the Spread of Porcine Reproductive and Respiratory Syndrome Among Pig Farms in Lira District of Northern Uganda

Porcine Reproductive and Respiratory Syndrome (PRRS) is a viral swine disease that causes reproductive failure in breeding sows and respiratory distress in growing pigs. The main objectives were to simulate the transmission patterns of PRRS in Uganda using North American Animal Disease Spread Model (NAADSM) and to evaluate the potential effect of prevention and control options such as vaccination and movement control. The median number of infectious farms at the end of 52 weeks for the baseline scenario was 735 (36.75% of the 2,000 farms). The best effects of vaccination were observed in scenarios 60% farm coverage and 80% farm coverage, which resulted in 82 and 98.2% reduction in the median number of infectious farms at the end of the simulation, respectively. Vaccination of all medium and large farms only (33% of the farms) resulted in a 71.2% decrease in the median number of infectious farms at the end of 52 weeks. Movement control (MC) results showed that the median number of infectious farms at the end of 52 weeks decreased by 21.6, 52.3, 79.4, and 92.4% for scenarios MC 20, MC 40, MC 60, and MC 80%, respectively. This study provides new insights to the government of Uganda on how PRRS can be controlled. The large and medium farms need to be prioritized for vaccination, which would be a feasible and effective way to limit the spread of PRRS in Uganda. Scavenging pigs should be confined at all times, whether in the presence or absence of any disease outbreaks.

Anti-Classical Swine Fever Virus Strategies

Classical swine fever (CSF), caused by CSF virus (CSFV), is a highly contagious swine disease with high morbidity and mortality, which has caused significant economic losses to the pig industry worldwide. Biosecurity measures and vaccination are the main methods for prevention and control of CSF since no specific drug is available for the effective treatment of CSF. Although a series of biosecurity and vaccination strategies have been developed to curb the outbreak events, it is still difficult to eliminate CSF in CSF-endemic and re-emerging areas. Thus, in addition to implementing enhanced biosecurity measures and exploring more effective CSF vaccines, other strategies are also needed for effectively controlling CSF. Currently, more and more research about anti-CSFV strategies was carried out by scientists, because of the great prospects and value of anti-CSFV strategies in the prevention and control of CSF. Additionally, studies on anti-CSFV strategies could be used as a reference for other viruses in the Flaviviridae family, such as hepatitis C virus, dengue virus, and Zika virus. In this review, we aim to summarize the research on anti-CSFV strategies. In detail, host proteins affecting CSFV replication, drug candidates with anti-CSFV effects, and RNA interference (RNAi) targeting CSFV viral genes were mentioned and the possible mechanisms related to anti-CSFV effects were also summarized.