About

Gustavo Machado is associated with the College of Veterinary Medicine at NC State University, which is dedicated to shaping the future of veterinary medicine and supporting the next generation of veterinarians. The college emphasizes a collaborative and caring culture, fostering student achievement and well-being through academic programs, research opportunities, and extracurricular activities. While specific details about Dr. Machado's research focus, background, or key contributions are not provided in the page text, his association with the college suggests involvement in advancing veterinary education and research.

Research topics

• Biology
• Veterinary medicine
• Medicine
• Virology
• Environmental health
• Ecology
• Environmental planning
• Environmental protection
• Agroforestry
• Geography
• Animal science
• Socioeconomics

Selected publications

• Modelling the transmission and vaccination strategy for porcine reproductive and respiratory syndrome virus

  Transboundary and Emerging Diseases · 2021 · 38 citations

  Senior authorCorresponding
  • Biology
  • Veterinary medicine
  • Virology

  Many aspects of the porcine reproductive and respiratory syndrome virus (PRRSV) between-farm transmission dynamics have been investigated, but uncertainty remains about the significance of farm type and different transmission routes on PRRSV spread. We developed a stochastic epidemiological model calibrated on weekly PRRSV outbreaks accounting for the population dynamics in different pig production phases, breeding herds, gilt development units, nurseries and finisher farms, of three hog producer companies. Our model accounted for indirect contacts by the close distance between farms (local transmission), between-farm animal movements (pig flow) and reinfection of sow farms (re-break). The fitted model was used to examine the effectiveness of vaccination strategies and complementary interventions such as enhanced PRRSV detection and vaccination delays and forecast the spatial distribution of PRRSV outbreak. The results of our analysis indicated that for sow farms, 59% of the simulated infections were related to local transmission (e.g. airborne, feed deliveries, shared equipment) whereas 36% and 5% were related to animal movements and re-break, respectively. For nursery farms, 80% of infections were related to animal movements and 20% to local transmission; while at finisher farms, it was split between local transmission and animal movements. Assuming that the current vaccines are 1% effective in mitigating between-farm PRRSV transmission, weaned pigs vaccination would reduce the incidence of PRRSV outbreaks by 3%, indeed under any scenario vaccination alone was insufficient for completely controlling PRRSV spread. Our results also showed that intensifying PRRSV detection and/or vaccination pigs at placement increased the effectiveness of all simulated vaccination strategies. Our model reproduced the incidence and PRRSV spatial distribution; therefore, this model could also be used to map current and future farms at-risk. Finally, this model could be a useful tool for veterinarians, allowing them to identify the effect of transmission routes and different vaccination interventions to control PRRSV spread.

  DOI

• Nairobi Sheep Disease Virus: A Historical and Epidemiological Perspective

  Frontiers in Veterinary Science · 2020 · 65 citations

  Senior authorCorresponding
  • Geography
  • Socioeconomics
  • Environmental protection

  Nairobi Sheep Disease virus (NSDv) is a zoonotic and tick-borne disease that can cause over 90% mortality in small ruminants. NSDv has historically circulated in East Africa and has recently emerged in the Asian continent. Despite efforts to control the disease, some regions, mostly in warmer climates, persistently report disease outbreaks. Consequently, it is necessary to understand how environmental tolerances and factors that influence transmission may shed light on its possible emergence in other regions. In this study, we quantified the available literature of NSDv from which occurrence data was extracted. In total, 308 locations from Uganda, Kenya, Tanzania, Somalia, India, Sri Lanka and China were coupled with landscape conditions to reconstruct the ecological conditions for NSDv circulation and identify areas of potential disease transmission risk. Our results identified areas suitable for NSDv in Ethiopia, Malawi, Zimbabwe, Southeastern China, Taiwan, and Vietnam. Unsuitable areas included Democratic Republic of Congo, Zambia, and Southern Somalia. In summary, soil moisture, livestock density, and precipitation predispose certain areas to NSDv circulation. It is critical to investigate the epidemiology of NSDv in order to promote better allocation of resources to control its spread in regions that are more at risk. This will help reduce disease impact worldwide as climate change will favor emergence of such vector-borne diseases in areas with dense small ruminant populations.

  DOI

• Porcine reproductive and respiratory syndrome virus dissemination across pig production systems in the United States

  Transboundary and Emerging Diseases · 2020 · 45 citations

  Senior authorCorresponding
  • Biology
  • Veterinary medicine
  • Virology

  and farms located at a range within 0.5 km and 0.7 km from major roads were more likely to be infected by PRRSV, whereas farms at an elevation of 41 to 61 meters and surrounded by denser vegetation were less likely to be infected, indicating their role as dissemination barriers. In conclusion, our results demonstrate that external dissemination was intense, and reinforce the importance of farm proximity on PRRSV spread. Thus, consideration of farm location, geographic characteristics and animal densities across production systems may help to forecast PRRSV collateral dissemination.

  DOI

Frequent coauthors

• Aleksandro S. Da Silva

  Universidade do Estado de Santa Catarina

  50 shared

• Matheus D. Baldissera

  37 shared

• Nathieli B. Bottari

  Universidade Federal de Pelotas

  32 shared

• Jason A. Galvis

  26 shared

• Maria Rosa Chitolina Schetinger

  Universidade Federal de Santa Maria

  26 shared

• Vera Maria Morsch

  Universidade Federal de Santa Maria

  25 shared

• Nicolás Céspedes Cárdenas

  North Carolina State University

  24 shared

• Lenita M. Stefani

  23 shared

Education

• PhD, in Veterinary Epidemiology

  Universidade Federal do Rio Grande do Sul

  2016

• Master in Veterinary Epidemiology

  Universidade Federal do Rio Grande do Sul

  2013

Similar researchers at North Carolina State University

• Jonathan Lindseyh-101
• Edward Breitschwerdth-100
• José Alonsoh-94
• Rob Dunnh-94
• Frances S. Liglerh-92