Bluetongue

Bluetongue is a non-contagious, viral disease affecting both domestic and wild ruminants with a high morbidity and mortality, transmitted by the bites of Culicoides midges. The virus belongs to the Sedoreoviridae family and consists of 24 recognized serotypes.

Affected species

Sheep
Sheep
Goats
Goats
Cattle
Cattle
Deer
Deer

Risk Factors

Bluetongue virus (BTV) is endemic in tropical and subtropical regions. However, the global distribution and nature of BTV infection has changed significantly in recent years, and climate change has been identified as a potential cause.
Since 2006, BTV has expanded further into Western Europe reaching as far north as 58° N, representing a new wave of expansion.

01

Increase of vector spread

  • Higher temperatures
  • Less rainfall
  • Stagnant water
02

Subclinical reservoirs infected

Hosts with few or no signs or symptoms of infection can transmit the virus to the midges, which then infect other animals.

03

Introduction of susceptible animals in endemic areas

TRANSMISSION OF BLUETONGUE VIRUS

The majority of Bluetongue virus (BTV) transmission takes place quietly among host animals that have developed resistance to the disease. Cattle serve as the primary reservoir in most areas, often carrying the virus without showing clinical symptoms and occasionally experiencing extended periods of viral presence in their bloodstream, lasting up to 100 days.

After biting an infected animal, the midge ingests the virus, leading to infection in the midge’s gut cells. The virus then replicates within these cells, escapes into the insect’s body cavity (haemocoel) and proceeds to infect and replicate within the salivary glands. Only after this process is complete can the virus be transmitted to a new host.

  • Biological Vector
    Infected midges can be carried by winds up to 300 km (180 miles)
  • Transplacental transmission
    This kind of transmission only happens in serotype 8

SIGNS AND SYMPTOMS OF BLUETONGUE

Clinical cases of BTV occur mainly in sheep, while subclinical infection (with no signs) seem to predominate in most other species.

  • Hemorrhage & Edema
  • Oral and nasal lesions: tissue ulceration, salivation, nasal discharge, swelling of lips, tongue and jaw, cyanosis of the tongue (blue tongue)
  • Pedal lesions: Coronary inflammation and lameness
  • Temporary infertility and miscarriages
  • Weight loss

Cases of subclinical disease make it difficult to diagnose Bluetongue disease and allow the virus to replicate and spread.

ECONOMIC LOSSES

 

There are also other indirect costs like having to slaughter animals as it is difficult to control the disease. Asymptomatic animals are carriers and reservoirs of the virus, causing the spread of the bluetongue virus.

HOW TO CONTROL AND PREVENT BLUETONGUE

Prevention: The best solution

Manejo
La mejora de los métodos y la higiene durante la manipulación del ganado puede contribuir a reducir la presencia de los agentes patógenos.

Selección genética
Selección de terneras resistentes a la mastitis.

Vacunación
Una de las medidas de prevención más eficaces es reforzar la inmunidad frente a la mastitis mediante la vacunación.

DR. FRANCISCO JAVIER ORTEGO

Researcher  at Animal Health Research Center (CISA-INIA)

Dr.Francisco Javier Ortego completed his PhD dissertation at Hospital Ramón y Cajal in Madrid under the supervision of Dr. Rafael Fernández Muñoz. He then pursued two postdoctoral studies for a total of 10 years, first at Yale University in the US and then at the National Center for Biotechnology of the CSIC in Madrid, where he held a reinstatement contract from the Ministry of Education and Science and an I3P contract from the Ministry of Science and Technology.

In February 2005, he joined the Animal Health Research Center (CISA-INIA/CSIC) as a Ramón y Cajal researcher and later became a Full Scientist of OPIs in 2008. Since then, he has been conducting research in the field of developing and optimizing universal vaccines against arboviruses relevant to animal health, focusing on the bluetongue and African horse sickness viruses.

In 2022, he participated in three projects, two as a Co-IP, which aimed to create and asses COVID-19 vaccines. Additionally, he served as Deputy of the National Agency for Evaluation and Prospecting (ANEP) from 2015 to 2017, and later as coordinator of the Livestock and Aquaculture (GYA) sub-area of the AEI from 2017.

 

 

HOW TO CONTROL AND PREVENT BLUETONGUE

Prevention: The best solution

Manejo
La mejora de los métodos y la higiene durante la manipulación del ganado puede contribuir a reducir la presencia de los agentes patógenos.

Selección genética
Selección de terneras resistentes a la mastitis.

Vacunación
Una de las medidas de prevención más eficaces es reforzar la inmunidad frente a la mastitis mediante la vacunación.

Bluetongue virus vaccine

BLUEVAC BTV

Range of inactivated vaccines to control and prevent bluetongue virus disease (Serotypes 1, 4 and 8).