Eradication of Rinderpest And The Probability of RECURRENCE

No matter how time flies by, when we talk about pandemics in the animal population, one name stands out – RINDERPEST – also known as cattle plague.

Pandemics suck, right? I know we can share this experience after the world has been engulfed in the COVID-19 pandemic since the last two months of 2019. 

Pandemics do not occur only in human populations; they occur in animal populations too – and even more frequently than we can imagine!

How Rinderpest Affected Lives

Rinderpest was a source of pain, suffering, and persistent trouble throughout the world, especially in Europe, Asia and Africa. 

It killed off cattle herds and wild animals hunted as game, leading to disruption of meat security globally. This affected the livelihoods of many families, increased poverty, led to famines, and caused the death of countless humans as a result of the famine.

Farmlands had no draught animals to plow, no dung to use as fertilizers, and the famine was not just a result of lack of meat but lack of food crops too. Parents sold their children to slave masters with the hope that they would be fed. People traveled wide and far to find food.

With the loss of wild animals, which served as prey for lions, hyenas, and jackals, these animals turned to attack weakened, starved humans for their next meal. 

Even though Rinderpest was eradicated in Europe and the Americas after 1930, its effect was seen in the other parts of the world, and it was horrific.

What is Rinderpest?

Rinderpest (German) is also known as the Cattle plague, Steppe Murrain, or Contagious Bovine Typhus. It is a highly contagious viral disease that affected cattle and buffaloes primarily. It also affected other ruminants (animals that chew the cud and have cloven hooves), both wild and domestic. It is the most deadly plague in cattle, water buffalo, yaks, and giraffe populations.

It is believed that rinderpest was first discovered in Central Eurasia, and due to trade and migration, it spread to Asia, Africa, and Europe. It was also reported in lower numbers in Australia and America.

Rinderpest emerged and rapidly spread as a result of four increased human activities – increased power and status by the number of draught cattle, increased dependence on cattle for meat, trading of livestock, and providing supplies during the war, and also sending a large number of livestock back home as loot.

The effects of rinderpest and the desire to combat this disease led to the formation of the first veterinary school in the world in Lyon, France, in 1762. It also led to the World Organisation for Animal Health (OIE) formation, translated from French as Office International des Epizooties (OIE), in 1924.

The Eradication of The Rinderpest Virus

The rinderpest virus is the first animal virus to be eradicated globally but the second viral disease after smallpox (human viral disease). This was done as a joint effort of the World Organization for Animal Health (OIE) and the UN Food and Agricultural Organization (FAO).

They set up an eradication campaign known as the Global Rinderpest Eradication Programme (GREP) in 1994 and set a deadline for eradicating rinderpest by 2010.

The eradication was achieved by administering vaccines from 1960 to cattle herds and domestic buffaloes less than a year old within the endemic regions (prevalent areas). The vaccine, Tissue Culture Rinderpest Vaccine (TCRV), was developed by Plowright in 1960 led him to receive the World Food Prize in 1999. 

TCRV followed a strict cold chain policy (keeping the vaccines cold all the time) and thus couldn’t be sent to hard-to-reach communities. It was used in areas that were easily accessible. 

Following the challenges of the TCRV, Tufts University, School of Veterinary Medicine, and the US Department of Agriculture developed a vaccine ThermoVax which did not require strict cold chain observation. This could be transported on bicycles or even by animals to rural areas and made eradication possible in hard-to-reach communities.

Local herd keepers were selected and trained and were known as Community Based Animal Health Workers (CBAHW). CBAHW was very instrumental in vaccinating herd in remote terrains and areas in war-torn zones. 

Quarantine proved to be an essential method in curbing the disease long before introducing vaccines, as the transmission of the virus needed close contacts between herds. 

Introducing inactivated viruses from sick animals into healthy animals through inoculation was one way to protect herds. This was done by mixing the serum (liquid in clotted blood after centrifuging) of an animal recovered from rinderpest with the blood of an animal suffering from rinderpest. This provided long-term immunity.

Other methods used to eradicate rinderpest included slaughtering infected and exposed animals and controlling animal movements between regions.

Due to the amount of damage rinderpest caused local families, countries, and the world as a whole, people were very much eager to help in the eradication by participating in the above regimes with all diligence.

The latest outbreak occurred in Kenya in 2001, and after 10-year global surveillance, rinderpest was declared eradicated on 25th May 2011 by the OIE.  

Transmission and Etiology of the Disease

Transmission of rinderpest mainly involves inhalation of viral droplets from infected cattle, buffaloes, and yaks’ nasal, ocular and fecal discharges. 

After 1-2 days of infection, the infected animal begins to shed the virus even before clinical signs develop. Infected animals shed the virus through discharges from their nose and eyes through close contact. 

The transmission did not occur through infected fomites (inanimate objects) as the virus did not last long being exposed to the atmosphere. Transmission through food and water contaminated with discharges from the affected animal can also occur.

Rinderpest is caused by a virus known as Morbillivirus. This virus belongs to a family of viruses (Paramyxoviridae) that can highly cause diseases such as measles in humans, canine distemper, pestes des petits ruminants in small ruminants (sheep and goats). 

Rinderpest is not zoonotic, and insect vectors do not transit it.

The Lessons Learnt About Rinderpest

The successful eradication of Rinderpest shows that with joint effort, based on scientific evidence, most viral diseases can be eradicated. Eradication programs need to be time-bound to have a goal and a sense of urgency in mind.

The eradication of rinderpest has also taught us that with much collaboration known as One Health, where veterinary, human, and environmentalist/ecologists work together, we can eradicate many diseases. 

Also, adequate studying of the spread of the disease (epidemiology) in the affected and prone species was critical compared to just relying on vaccination programs. 

Veterinary services should be strengthened in various countries especially developing countries, to aid in adequate testing, reporting, and surveillance measures. 

How is Rinderpest Recognised?

An animal sick with the rinderpest virus has a fever and discharges from the nose and mouth.

There’s lack of appetite, gastroenteritis (inflammation of the stomach and intestines) in the form of diarrhea and dysentery, inflammation of the mucous membranes of the mouth, which usually has eroded sores (known as erosive stomatitis), and death of the cells and tissues of the lymph nodes especially the Peyer’s patches (lymphoid necrosis). 

Lesions also occur on the vulva and vagina. There’s labored, painful breathing that occurs as the disease progresses. The animal lies on its sternum (chest bone), and death follows shortly after the body has been wasted.

Death usually occurs through loss of fluid and electrolytes from diarrhea and dysentery, loss of protein, suppression of the immune system due to the loss of lymphoid tissues.

Rinderpest also has high morbidity (feeling sick) and mortality (number of deaths) and can wipe an entire herd within a twinkle of an eye. 

Rinderpest is closely related to foot and mouth disease (FMD) and can be differentiated by the lameness accompanying FMD and the formation of vesicles in the mouth.

The Risk of Rinderpest Re-emerging

Rinderpest can re-emerge in future animal populations even though the virus does not exist in nature. It is a possibility both the FAO and the OIE are working hard to prevent.

A Global Action Plan by the FAO and the OIE has been laid out to ensure that Rinderpest doesn’t re-emerge again. The plan has five phases: preparation, prevention, detection, response, and recovery.

Various samples containing rinderpest contaminated materials and viral samples being kept for studies are awaiting final destruction.

Important laboratories designated by the OIE and FAO keeping samples of the virus for scientific studies must prevent any spill-over into the population by maintaining high biosecurity measures.   

The veterinary community has been tasked to be vigilant to detect and trace any source of rinderpest outbreaks in any country should the need arise.

With effective disease surveillance, communication, and training of veterinarians by the FAO and OIE, rinderpest would be a historical figure.

Summary

Rinderpest destroyed the livelihood of many people and the economies of many counties. Its eradication came as good news to the whole world. Eradication can only occur through scientific-based evidence and combined efforts from people all over the world.

The success of the eradication of rinderpest has led to an increased hope for many animal viral diseases such as pestes des petitis ruminants in the eradication fight.