July 2020 – Swine in Minnesota

Incidence Risk and Incidence Rate: an Overview

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Today, Dr. Juan Sanhueza helps us understand better two epidemiologic concepts: the incidence risk and incidence rate.

Key Points

Incidence risk is a measure of disease occurrence over a defined period of time. It is a proportion, therefore takes values from 0 to 1 (0% to 100%)
Incidence rate takes into account the time an individual is at risk of disease. It is not a proportion since it defines the number of cases per animal or farm time at risk.
Incidence risk and incidence rate are often confused. Incidence risk and rate are numerically the same when the period at risk does not vary across individuals being studied.

Use of test and removal strategy to contain an ASFV outbreak in a farm

Every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Today, Dr. Yao and collaborators from PIC, New Hope Liuhe, and University of Cambridge describe the implementation of a test and removal strategy on an African Swine Fever virus (ASFV) infected farm, highlighting the importance of early detection and rapid responses to contain the virus in a population.

Morrison Swine Health Monitoring Project: Annual Summary (2019/2020)

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Another MSHMP year has gone by and certainly will be one to remember due to the public health emergency leading to a crisis in our industry. Today, Dr. Cesar A Corzo provides comprehensive 2019/2020 concluding remarks and project updates. Thank you to all MSHMP participants for continuing to communicate and report status changes!

Effect of influenza A virus sow vaccination on infection in pigs at weaning: A prospective longitudinal study

Dr. Chamba Pardo and colleagues from the University of Minnesota share results of the implementation of sow vaccination to control influenza infections in pigs at weaning through a special issue article published in Transboundary and Emerging Diseases.

Highlights

Sow vaccination against IAV was effective at reducing the number of infected groups of pigs at weaning, and the number of positive nasal swab pools within a group.
Both prefarrow or whole herd vaccination protocols, and use of commercial or autogenous inactivated vaccines, yielded significant and similar reduction of IAV infections in pigs at weaning.
Sow vaccination can help control IAV infections in pigs at weaning and, thus, minimize transmission to growing pigs and other farms.

Exploring heterologous prime-boost vaccination approaches to enhance influenza control in pigs

Chong Li and colleagues from the University of Minnesota provide new insights for the potential use of the heterologous prime-boost vaccination strategy to control swine infuenza A virus (IAV) infection in pigs by bringing us a research article published in Veterinary Research.

Highlights

Heterologous prime-boost vaccination has the potential to deal with diverse IAV infection in multiple animal models.
Pigs in the heterologous prime-boost vaccination group had more favorable outcomes consistent with a better response against virus challenge (H1N1 and H3N2 IAV) than non-vaccinated pigs.
Similarly, a multivalent heterologous inactivated vaccine boost to pigs following a single live attenuated IAV vaccine (LAIV) administration was also beneficial.
More studies are still needed to validate the concept of heterologous prime-boost to control IAV under feld conditions.