Feb 7, 2026

Guest Lectures Series on One Health Concept in Animal Science and Production

 


In his welcoming address on behalf of the Dean of the Faculty of Agriculture at the University of Mauritius, Mr. K. Boodhoo opened the lecture series by emphasizing the critical role of the One Health approach in controlling both animal and human diseases. In his address, Mr. Boodhoo expressed his gratitude to Dr. Charlena Poonyth for her initiative in reaching out to the Faculty to jointly organize the lecture series. He commended this collaborative effort, noting that such partnerships are vital for advancing the Faculty's mission in agricultural education and research. The other key points from the address were he highlighted that the integration of human, animal, and environmental health is essential for effective disease management. He noted with appreciation that the audience reflected the full spectrum of the One Health initiative, including representatives from the animal, human, and environmental health sectors. He also underscored the University's active role in fostering collaborative regional networks to address complex biosecurity challenges.  

The series of lectures were jointly delivered by Professor DVM Keita Matsuno Head of the Division of Risk Analysis and Management, Hokkaido University (Japan), and Mag. med. vet. Charlena Poonyth, in collaboration with the Faculty of Agriculture, University of Mauritius. Drawing on experiences from Japan and the Indian Ocean region, the session illustrated how One Health operates in practice, particularly through real-world examples such as vector-borne diseases, emerging zoonoses, and regional surveillance networks. Senior Researchers, Dr M.Dupraz and T.Baldet from The Réseau ASTRE (Animal Surveillance of Tropical Diseases) a regional surveillance network operatinin the Indian Ocean region, including islands such as Réunion, Mauritius, Madagascar, Comoros, and Seychelles., also gave an overview of the Research activities being carried out in the region.

The One Health concept, - A New Way to Think About Health.

Instead of just waiting for people to get sick and then treating them, the One Health approach focuses on stopping problems before they start. It looks at how the health of people, animals, and the environment are all connected. As global health challenges increasingly emerge at the interface of these three domains—through zoonotic diseases, vector-borne infections, environmental change, and food system pressures—One Health has become a central framework for prevention, risk analysis, and health management.

Think of One Health as a high-stakes "team sport" where doctors, veterinarians, and environmental scientists join forces to tackle health risks before they spiral out of control. Instead of just staying in textbooks, this practical approach focuses on how to actually anticipate, detect, and manage diseases in the real world where humans and animals live together. Because modern health threats don't care about country borders or species lines, the strategy relies heavily on international teamwork and shared data. By connecting the dots between our health, animal health, and the environment, experts can better protect the entire planet from complex biological threats

Vector Borne Diseases

Vector-borne diseases are among the clearest and most intuitive ways to understand the One Health concept in practice. Rather than appearing suddenly in humans, these diseases emerge from a chain of interactions between the environment, animals, and vectors that transmit pathogens. 

 Yezo Virus in a One Health Context

Yezo virus is a recently identified tick-borne virus and a compelling modern example of One Health in action. It was first detected and described by Professor Keita Matsuno himself, the speaker of this lecture, offering a unique opportunity to learn about One Health directly from the scientist involved in its discovery. First detected in people with fever in northern Japan, particularly on the island of Hokkaido, Yezo virus was linked to tick bites, highlighting the role of ticks as vectors connecting the environment, animals, and humans.

From a One Health perspective, Yezo virus does not originate in humans. Instead, it is maintained in natural ecosystems, where ticks feed on wild animals such as deer and rodents. These animals usually show no obvious signs of illness but act as reservoir hosts, allowing the virus to persist in nature. Ticks acquire the virus during blood feeding and can later transmit it to humans.

Environmental conditions play a key role in this process. Forested landscapes, suitable vegetation, moisture, and climate conditions support both tick survival and wildlife populations. Changes such as climate warming, expanding forests, and increased human outdoor activity increase contact between ticks and people, raising the risk of infection. Humans are therefore accidental hosts, becoming infected when they enter tick habitats for work or recreation.

Importantly, Yezo virus illustrates why tick-borne diseases cannot be prevented by human medicine alone. Treating patients does not reduce tick populations or interrupt transmission in wildlife. Effective prevention requires a One Health approach, combining environmental monitoring, wildlife surveillance, vector control, and public awareness measures such as tick avoidance and early removal.

By tracing Yezo virus from ecosystems to animals and finally to human disease, this example reinforces a central One Health message: human health outcomes are shaped long before infection occurs, through interactions between the environment, animals, and vectors. Read more here

Animal Disease Research 

As a vital component of her doctoral research, Dr. Charlena Poonyth provided a comprehensive overview of her proposed investigation into ruminant health and vector-borne diseases in Mauritius for the upcoming years. In Mauritius, ruminants—cattle, sheep, goats, and deer—are the quiet pillars of the national economy. They represent the primary livelihood for thousands of farmers, breeders, and butchers. Through the lens of the One Health paradigm, Dr. Poonyth's research addresses the urgent need for biosafety and surveillance, particularly focusing on pathogens like Crimean-Congo Haemorrhagic Fever (CCHF) and Heartwater Disease. Her project includes a landmark sampling mission scheduled for February 2026, which aims to establish the first nationwide database of vector-borne diseases across all nine districts of the island. This pioneer movement will pair specific vectors, such as Hyalomma and Amblyomma ticks, with the pathogens they carry to bring Mauritian biosecurity to international standards. Read more here

 The Culicoides

In the guest lectures, Culicoides biting midges and ticks were used as illustrative examples because they make these connections visible and easy to grasp. Both vectors are highly sensitive to environmental conditions such as climate, land use, and farming practices; they rely on animals to maintain and spread pathogens; and they ultimately affect human health directly (as with tick-borne diseases) or indirectly through livestock health, food security, and trade (as with Culicoides-borne viruses). By following how these vectors move through ecosystems and animal populations, we can clearly see why preventing vector-borne diseases requires a One Health approach, rather than focusing on human medicine alone.

The discussion highlighted how environmental factors such as climate change, moisture, and farming practices influence Culicoides populations and their distribution. These insects transmit important viral diseases of livestock, including bluetongue disease and Schmallenberg virus, which cause significant animal suffering, production losses, and economic damage. Through reduced milk and meat production, movement restrictions, and trade bans, these animal diseases have clear indirect impacts on human livelihoods and food security.

The talk emphasized that controlling Culicoides-borne diseases cannot rely on veterinary treatment alone. Instead, effective prevention requires a One Health approach, combining environmental management, vector surveillance, animal health monitoring, and coordinated policy responses. By following the pathway from environment to vector to animal and finally to human impact, the talk demonstrated how Culicoides midges provide a clear and accessible illustration of One Health in action. Read more here

Tick Borne Diseases

The talk used ticks as a clear and intuitive example to demonstrate how vector-borne diseases operate within the One Health framework. Ticks were presented as vectors that directly connect environmental conditions, animal hosts, and human disease, making them especially useful for understanding how health risks emerge across systems rather than in isolation.

The discussion explained how ticks depend on specific environmental factors, including vegetation, humidity, temperature, and climate stability. Changes such as warmer winters, reforestation, and land-use change were shown to increase tick survival and expand their geographic range. These environmental shifts directly influence tick abundance and the risk of disease transmission.

The role of animals was highlighted as central to the tick life cycle. Wildlife such as rodents and deer maintain tick populations and the pathogens they carry, often without showing signs of illness. Domestic animals and pets can also transport ticks into human environments, increasing exposure. Humans, by contrast, are accidental hosts, becoming infected through outdoor activities such as farming, forestry, or recreation.

The talk emphasized that tick-borne diseases cannot be effectively controlled through human medicine alone. Instead, prevention requires a One Health approach, combining environmental management, wildlife and animal surveillance, vector control, and public awareness. By tracing disease risk from ecosystems to animals and finally to humans, the talk demonstrated how ticks provide a powerful real-world illustration of One Health in practice. Read more here

Biodata of the Key Speakers

Dr Charlena Poonyth is a veterinarian and current PhD student at Hokkaido University in Japan. Her current doctoral research focuses on the critical field of emerging vector-borne diseases. She earned her Diploma of Veterinary Medicine from the University of Veterinary Medicine, Vienna , and has developed a professional specialization in ruminant health and integrative medicine. In addition to her research, Charlena is a Certified Veterinary Acupuncturist. She brings a truly international perspective to her work, having completed clinical internships in Germany, Austria, and Thailand , and she is proficient in English, French, German and intermediary Japanese.  

Professor Dr. Keita Matsuno is  the Head of the Division of Risk Analysis and Management at Hokkaido University and a key member of the One Health Research Center. As a veterinarian and virologist, he has dedicated his career to the discovery and characterization of emerging zoonotic viruses. His work is perhaps most widely recognized for the 2021 discovery of the Yezo virus, a novel pathogen found in Hokkaido that causes acute febrile illness in humans. Beyond virus discovery, Dr. Matsuno’s research into the pathogenesis of Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) has provided critical insights into how these diseases impact both wildlife and human populations. Through his efforts in developing advanced diagnostic tools and his advocacy for the One Health initiative, Dr. Matsuno is playing a vital role in global preparedness against the next generation of zoonotic epidemics.

Dr. Marlene Dupraz is a senior researcher with the ASTRE research unit (CIRAD-INRAE), based at the Cyroi technological platform right here in La Réunion. A specialist in ticks and tick-borne diseases, she holds a PhD from the University of Montpellier, where her early research focused on the complex evolutionary relationships between ticks and seabirds. Her current work is at the forefront of vector biology and ecology. She investigates the adaptive relationships between infectious agents and their hosts, with a particular focus on disease control methods and the growing challenge of acaricide resistance. Beyond ticks, her expertise extends to supporting research on mosquitoes and other biting flies. Dr. Dupraz is a key contributor to the One Health Indian Ocean network and maintains active international collaborations with partners in the Caribbean, Australia, and Cuba to improve integrated vector management globally.

 

Dr. Thierry Baldet is a senior research scientist with the ASTRE research unit, a joint initiative between CIRAD and INRAE. With over 25 years of experience in the research, surveillance, and control of vector-borne diseases, he is a leading specialist in managing emerging health risks. He holds a PhD from the University of Montpellier and has a distinguished international career, having worked extensively across Africa and Europe, as well as serving as a Senior Program Specialist for the IDRC in Canada. Throughout his career, he has provided high-level expertise for global organizations such as the World Health Organization (WHO) and the European Food Safety Authority (EFSA). Currently based at the CYROI technological platform in La Réunion, Dr. Baldet serves as the coordinator for the One Health Indian Ocean network. This regional partnership is vital for the prevention and control of infectious risks and antibiotic resistance across the region.

 

 

 

 


 

Culicoides and Arbovirus Dynamics in Mauritius and the Southwest Indian Ocean

 


1. Taxonomic and Biological Overview of Culicoides

Culicoides are very small biting midges (1 to 3 mm) belonging to the family Ceratopogonidae. Their biological characteristics and classification are critical for identifying vector potential:

  • Classification:
    • Phylum: Arthropoda.
    • Class: Insecta (Hexapoda).
    • Order: Diptera.
    • Family: Ceratopogonidae.
  • Global Diversity: There are approximately 5,400 species within the family across 50 genres. However, only four genres are of medical or veterinary interest: Leptoconops, Austroconops, Forcipomyia, and Culicoides.
  • Vector Specificity: Of the 1,400 Culicoides species identified worldwide, approximately 60 are confirmed vectors of pathogens. Identification is primarily achieved through wing coloration patterns.
  • Life Cycle: The cycle involves four stages: Eggs, Larvae (4 stages), Pupae, and Adults.
    • Environmental Requirements: Larvae develop in humid zones rich in organic matter.
    • Trophogonic Cycle: Adult females require a blood meal for egg maturation and oviposition.

2. Arboviral Threats and Economic Impact

The emergence and spread of arboviruses transmitted by Culicoides have severe sanitary and economic consequences globally and regionally.

Veterinary Pathogens

  • Bluetongue Virus (BTV) & Epizootic Hemorrhagic Disease Virus (EHDV): Between 2022 and 2025, Europe experienced a major economic crisis due to these viruses, resulting in high morbidity, loss of fertility, movement restrictions for animals, and high vaccination costs.
  • African Horse Sickness (AHSV): A 2020 outbreak in Thailand demonstrated the extreme lethality of this virus, with 394 deaths out of 438 confirmed cases (a 90% lethality index).
  • Orbiviruses in Mauritius: Historically, orbiviruses were detected in Rusa deer in Mauritius as early as 2007.

Human Pathogens: The Oropouche Virus (OROV)

OROV is a zoonotic arbovirus primarily transmitted by Culicoides paraensis and certain mosquitoes.

  • Recent Emergence (2024-2025):
    • South/Central America: Over 11,600 confirmed cases across 12 countries in 2024, rising to 12,786 in 2025.
    • Clinical Severity: Recent outbreaks in Brazil have reported deaths in healthy individuals, cases of Guillain-Barré syndrome, and vertical transmission leading to fetal death and neonatal microcephaly.
    • Imported Risk: In July 2024, 19 cases were imported into Europe and 21 into the USA, primarily from Cuba.
  • Regional Context for French Territories: Presence of C. paraensis has been confirmed in French Guiana and Martinique, and was detected in Guadeloupe in 2025, raising the risk level to "High" according to PAHO (2024).

3. Situation Analysis: Mauritius

Mauritius has a history of research partnership regarding animal health, though faunal inventories remain incomplete.

Species Inventory and Distribution

Recent work, including the thesis of Yannick Grimaud and research by Iyaloo et al. (2025), identifies four major species on the island:

  1. Culicoides imicola (A primary vector of BTV and AHSV).
  2. Culicoides bolitinos.
  3. Culicoides enderleini.
  4. Culicoides kibatiensis.

Historical Milestones

  • 1992: Initial census identified C. imicola and other afrotropical species.
  • 2007: Detection of orbiviruses in the local Rusa deer population.
  • 2025-2026: Implementation of spatial-temporal monitoring and trans-island spatial transects.

Regional Connectivity

Research is investigating the phylogenetic links between Culicoides populations in Mauritius and La Réunion. There is a hypothesis of passive aerial transport (wind-borne) between the two islands, which may influence the spread of BTV and EHDV.

4. Strategic Research and Future Perspectives (2026)

The roadmap for Mauritius involves several high-priority research initiatives scheduled for 2026:

Objective

Description

Timeline

Anthropophile Assessment

Verify the presence of Culicoides outside of livestock areas to assess human risk (OROV).

2026

Rodrigues Inventory

Conduct an entomological census of Culicoides in livestock holdings on Rodrigues island.

April-May 2026

Multi-Vector Mission

Animal health mission involving dedicated researchers (Marlène & Brice).

Feb-March 2026

Modeling

Development of spatial-temporal models to track BTV and EHDV circulation.

Ongoing

Genetics

Study the genetic structure and gene flow of C. imicola across the SWIO region.

Ongoing

5. Methodology and Technological Innovation

Effective surveillance is currently hampered by the limitations of existing technology and taxonomic expertise.

Surveillance Tools and Challenges

  • Trapping Limitations: The standard Onderstepoort Veterinary Institute (OVI) trap is no longer commercialized and is ineffective for anthropophilic species like C. paraensis.
  • Innovation: There is a pressing need to develop and test home-made trap alternatives, such as those designed by David Wilkinson and Albin Fontaine (adapted for Culicoides).
  • Sample Strategy: Emphasis is placed on taking representative samples of circulating viruses rather than sheer quantity, ensuring the system is not saturated.

Advanced Detection Technologies

  1. MX Technology: A proof of concept has demonstrated that viruses transmitted by Culicoides can be detected using MX technology.
  2. Early Detection: Implementation of early detection systems for BTV and EHDV in sheep and cattle holdings.
  3. Metabarcoding: Utilization of metabarcoding for precise vector identification.
  4. Genotypic Characterization: Used to trace the origin and propagation of viral strains.

Regional Expertise

The "One Health OI" partnership provides a published methodological corpus, including morphological identification keys for the Culicoides of the Mascarene Islands and regional mapping of C. imicola. However, taxonomic expertise remains limited in areas like the Comoros and Madagascar due to the high diversity of the afrotropical region.

Case Study Analysis: The Discovery of the Ezo Virus and the One Health Approach

 


 

1. Introduction: The One Health Perspective in Hokkaido

The "One Health" approach is a transdisciplinary framework that recognizes the inextricable link between human health, animal health, and the health of our shared environment. This perspective is foundational to modern zoonotic disease surveillance, as emerging pathogens do not exist in a vacuum but circulate through complex ecological networks.

Hokkaido, Japan, serves as a premier case study for this intersection. The capital city, Sapporo, is a densely urbanized center surrounded by lush green spaces and mountainous terrain. This proximity creates a "blurred boundary" where human habitats are remarkably close to tick habitats. During fieldwork, researchers find that even on a paved road used by hikers, flipping just a few leaves can reveal hundreds of ticks. The ecology of these diseases is further dictated by Hokkaido's extreme seasons:

  • The Snow Season: Heavy snowfall—often reaching the height of a car—requires residents to navigate narrow, cleared roads. This period provides a natural reprieve from tick activity, allowing for intensive laboratory analysis and viral characterization.
  • The Summer Season: As the snow melts, tick activity surges, necessitating "fighting with ticks" in the field to monitor viral circulation.

Mission: Division of Risk Analysis and Management

Housed within the International Institute for Zoonosis Control at Hokkaido University, this division operates with a core mission to expand diagnostic capacity. By analyzing pathogens in ticks, wildlife, and humans, the team seeks to identify novel zoonotic threats before they escalate into public health crises, bridging the gap between clinical observation and laboratory identification.

The environmental intimacy between Sapporo’s urban sprawl and the surrounding wilderness created the exact conditions necessary for a new medical mystery to emerge from the undergrowth.

2. The Mystery: Clinical Detection and the "Diagnostic Gap"

Between 2019 and 2020, clinicians in Hokkaido encountered patients presenting with severe febrile symptoms that defied standard diagnosis. This illustrates a critical "Diagnostic Gap": in Japan, approximately 40% of febrile illnesses remain undiagnosed. Traditional diagnostic labs typically test only for suspected pathogens; if a virus is not yet identified or specifically requested, it remains invisible to the healthcare system.

Comparison of Initial Clinical Cases

Feature

Patient 1 (2019)

Patient 2 (2020)

History

Tick bite; removed the tick himself

Tick bite

Primary Symptoms

High fever, difficulty walking

High fever

Clinical Markers

Leukopenia & Thrombocytopenia

Leukopenia & Thrombocytopenia

Hospitalization

Required (severe case)

Not required (Ambulatory/Outpatient)

Outcome

Recovered and discharged

Recovered

 

 Image of New Tick Virus Shows Nature Is Still Inventing Ways to Mess ...Source Newsweek.

 Despite negative results for known pathogens, the presence of thrombocytopenia (low platelet count) and leukopenia (low white blood cell count) strongly suggested a viral hemorrhagic fever. This clinical intuition prompted a collaboration with specialized researchers capable of comprehensive, open-ended pathogen discovery.

While the clinical setting identified the "what," the investigation shifted to specialized high-containment laboratories to uncover the "who."

3. Identifying the Pathogen: The Ezo Virus Revealed

 To isolate the unknown agent, researchers employed a combination of "classic" virology and high-throughput genetic sequencing. They inoculated patient serum into immunocompromised mice—highly susceptible due to their inability to produce interferon—and Vero E6 cells. Using Illumina sequencing, they identified a novel agent.

Classification and Structure: The pathogen was named Ezo virus (after the historical name for Hokkaido). It is a member of the Nairoviridae family within the Bunyavirus group. Its genetic architecture consists of three distinct RNA segments. Phylogenetically, it is most closely related to the Sulina virus, which was discovered in Romania in ticks attached to migratory birds, suggesting a broad, international circulation of related nairoviruses.

Clinical Markers of Ezo Virus Infection: Data from a study of 24 patients in Hokkaido reveals that Ezo virus causes a systemic infection with markers typical of "moderate" hemorrhagic fever. Unlike its more lethal relative, Crimean-Congo Hemorrhagic Fever (CCHF), no fatal cases of Ezo virus have been recorded to date. Key markers include:

  • Leukopenia: A precipitous drop in white blood cell counts during the febrile phase.
  • Thrombocytopenia: A sharp decline in platelet counts, hindering blood clotting.
  • Anti-coagulation Factors Loss: A disruption in the blood’s ability to regulate clotting, a hallmark of hemorrhagic fever.
  • Elevated Liver Enzymes: Clinical evidence of hepatic stress during the acute phase of infection.

Identifying the virus was only the first step; the "One Health" approach required researchers to step out of the lab and into the life cycle of the vector.

4. The Vector: The Life Cycle of the Three-Host Tick

The Ezo virus is not known to spread through human-to-human transmission; instead, it relies on the biological cycle of the three-host tick. In Japan, species such as Ixodes ovatus and Ixodes persulcatus serve as primary vectors. Virus transmission occurs only during blood feeding, which is required for the tick to molt into its next life stage.

The 3-Host Feeding Sequence:

  1. Larva: Prefers small animals (rodents/shrews) with thin skin that is easily penetrated.
  2. Nymph: Feeds on a second host—often medium-sized mammals like dogs or foxes—before molting.
  3. Adult: Seeks large animals (such as wild boar or deer) for the final blood meal required to produce eggs.

In the Japanese ecological context, Haemaphysalis longicornis is another significant species that bridges the gap between wild boars and domestic animals. Humans are "accidental" hosts in this cycle. Because the virus is tied to these developmental stages, human infections in Hokkaido are highly seasonal, peaking during the tick activity window of May and June.

Connecting the tick’s life cycle to the landscape requires mapping the specific animals that act as the virus's permanent residence.

5. Mapping the Reservoir: Wildlife and Environmental Circulation

To determine how Ezo virus persists in nature, researchers screened various wildlife populations. A key finding was that some viruses in this family show a 20% seropositivity rate in certain populations, indicating a high probability of infection for animals living in these habitats.

Reservoir Profile:

  • Small Shrews and Rodents: Identified as the primary natural reservoir. High infection rates suggest these species maintain the virus in a continuous cycle with larval and nymphal ticks.
  • Migratory Birds: Ticks carrying Ezo virus have been found on birds in Northern Hokkaido. This provides a mechanism for geographic "jumps," explaining how the virus may have moved between the Asian mainland and the island.
  • Deer and Raccoons: While both species are bitten by adult ticks (with raccoons being an invasive species in Japan), they showed lower seropositivity rates for Ezo, though they may play larger roles for other viruses like the Mukawa virus.

The evidence points to a robust natural cycle where the virus moves between shrews and ticks, occasionally spilling over into humans who venture near the "hiking-trail" interface.

While the Ezo virus mystery has been solved, it represents only one facet of a dynamic and evolving viral landscape.

6. Synthesis: Beyond Ezo—The Future of Zoonotic Surveillance

The discovery of the Ezo virus highlights a broader spectrum of emerging nairoviruses and phenuiviruses in East Asia. The threat level varies across the family: while Ezo is considered moderate, the Beiji virus—also found in China—has been linked to 67 cases and at least one death. Other agents, such as the Mukawa virus, have demonstrated the ability to suppress human innate immune functions (interferon production) in lab settings, marking them as pathogens of concern.

Preparedness requires constant surveillance, even for viruses that are not yet "notifiable diseases." Because islands like Hokkaido are dynamic ecological systems, viruses can disappear or be newly introduced by migratory species at any time.

One Health Checklist for Future Surveillance

  • Human Pillar: Conduct proactive screenings of healthy blood donors and undiagnosed febrile patients to identify "silent" or missed infections.
  • Animal Pillar: Monitor livestock, pets, and wild reservoirs (shrews/deer) to identify the exact window of virus replication to determine when these animals are most infectious.
  • Environmental Pillar: Maintain longitudinal tick population surveillance to track shifts in viral load across seasons and changing wildlife densities.

The discovery of Ezo virus is a reminder that the diagnostic gap can only be bridged through persistent, multi-species surveillance. In the dynamic ecology of an island, the next mystery is already circulating; our goal is to identify it before it finds a human host.

 

Tick Bornes Diseases

 


As human and commercial traffic intensifies, we are inadvertently facilitating the spread of diseases and parasites that threaten the very stability of regional agriculture. Organizations like CIRAD and the ASTRE (Animal, Santé, Territoires, Risques et Écosystèmes) research unit are monitoring, detecting, and preventing animal diseases, especially those that can: Spread across borders, Affect food production and livelihoods and Pose risks to human health. In her talk Dr M.Dupraz gave an over of the current tick borne diseases in the region.

1. A 19th-Century Legacy of Uninvited Guests

The tick crisis in the Indian Ocean is not a modern phenomenon but a persistent biological debt incurred during the height of colonial commerce. These parasites were originally introduced alongside ruminant imports from East and South Africa during the 19th century, with subsequent introductions arriving from Asia. This historical context reveals a profound irony: the same trade routes that built the region’s modern economy also imported a permanent ecological challenge.

"Dynamic region: high human and commercial traffic... Ticks imported with their ruminant hosts from East and South Africa in the 19th century, then from Asia."

This legacy reminds us that human "progress" often carries unintended biological baggage. By moving animals across oceans without modern biosecurity, we created a permanent shift in the regional ecosystem that farmers are still paying for over a century later.

2. Beyond the Bite: The Massive Economic Toll

A tick infestation is far more than a simple veterinary nuisance; it is a systemic drain on the region's prosperity. The damage is felt in two distinct waves that compromise both animal welfare and provincial food security.

Direct Impacts on Animal Health

  • Massive Blood Loss: Severe infestations lead to debilitating anemia and physical exhaustion.
  • Physical Trauma: Ticks cause painful abscesses and opportunistic skin diseases at the site of attachment.

Indirect Impacts and Economic Destabilization

  • Pathogen Transmission: Ticks serve as high-speed vectors for lethal bacteria and protozoa.
  • Production Decline: There is a sharp drop in growth rates and milk yields, directly threatening the food security of island populations.
  • Rising Costs: Smallholders face a mounting financial burden from veterinary fees and the purchasing of acaricides like Butox, often with diminishing returns.

3. A Rogues' Gallery of Deadly Pathogens

 

The ticks of the Indian Ocean are efficient biological delivery systems. Understanding the specific pathogens they carry is vital for "One Health" monitoring, as the windows for intervention are often incredibly narrow. The speed of mortality—sometimes as little as 24 hours after symptoms appear—makes these "tiny travelers" some of the most dangerous inhabitants of the islands.

Tick Species

Pathogen & Disease

Symptoms & Incubation

Treatment Outlook

Amblyomma variegatum

Ehrlichia ruminantium (Cowdriosis)

Sudden fever, nervous symptoms (stiffness, trembling). Incubation: 2–3 weeks.

Mortality in 1–6 days; requires urgent Tetracycline injection.

Rhipicephalus microplus

Babesia bovis/bigemina (Babesiosis) & Anaplasma marginale (Anaplasmosis)

High fever, jaundice, dark urine, anemia. Incubation: 1–4 weeks.

Treated with Imidocarb or Oxytetracycline; vaccines available.

Rhipicephalus evertsi

Nairobi sheep virus & Theileria parva (Theileriosis)

Hemorrhagic gastroenteritis, abortion, fever, lethargy. Incubation: 2–21 days.

Nairobi virus: No specific treatment. Theileriosis: Buparvaquone/Oxytetracycline.

4. The "Super-Tick" and the Failure of Chemical Warfare

For decades, the "Lutte chimique" (chemical control) has been the frontline defense. However, we have reached a dangerous tipping point. The species Rhipicephalus microplus has evolved into a "super-tick," showing widespread acaricide resistance. This crisis is exacerbated by a diminishing number of available active ingredients; as the molecules themselves become obsolete, the chemical "arms race" is being lost.

Currently, while products like Butox remain in use, the source context reveals a management void: Lutte génétique (genetic control) is currently "non appliquée" (not applied), and authorized vaccines are frequently unavailable. This over-reliance on a single, failing solution has only made the pests stronger. To combat this, we must pivot toward "Integrated Management." This includes difficult but necessary agronomic shifts such as:

  • Gyrobroyage: Mechanical brush clearing to destroy tick habitats.
  • Movement Monitoring: Strict tracking of animal transit to isolate infested zones.
  • Targeted Treatments: Moving away from blanket spraying toward strategic, data-driven applications.

Conclusion: The Road Toward Integrated Resilience

The future of the region depends on moving beyond the sprayer. Under the umbrella of the "One Health OI" partnership, researchers like Marlène Dupraz are developing a multi-pillar approach to resilience. By combining the inventory and mapping of species with molecular diagnosis and risk assessment, the goal is to create "Integrated control plans" that respect the link between the animal, the environment, and the human economy.

As we continue to enjoy the benefits of global connectivity, we must confront a difficult question: how can we balance the high-speed demands of international trade with the absolute necessity of local biological security?



An overview of Dr Charlena doctoral research in Mauritius


Dr. Charlena Poonyth provided a comprehensive overview of her proposed investigation into ruminant health and vector-borne diseases in Mauritius for the upcoming years. In Mauritius, ruminants—cattle, sheep, goats, and deer—are the quiet pillars of the national economy. They represent the primary livelihood for thousands of farmers, breeders, and butchers.

 The Silent Carriers: When "Mild" for Cows Means "Lethal" for Humans

The most dangerous pathogens are often the most deceptive. Crimean-Congo Haemorrhagic Fever (CCHF) is a prime example. In cattle and sheep, CCHF is remarkably "silent," typically manifesting as nothing more than a transient fever or mild lethargy. A farmer might see a cow that looks slightly "off" for forty-eight hours and think nothing of it.

However, CCHF is a severe zoonotic threat. In humans, this virus—a member of the Nairoviridae family—causes a devastating haemorrhagic disease with high mortality rates. Epidemiologically, we must also look at its genetic relatives to understand the full scope of the risk; for instance, Nairobi Sheep Disease is serologically and genetically related to CCHF, causing similar haemorrhagic symptoms and high mortality in small ruminants. When these "silent" reservoirs maintain a high viraemia (virus in the blood), they become a ticking clock for a public health crisis.

"There is an URGENT need for public health strategies!!!"

This urgency exists because clinical signs in animals are often insufficient for detection. By the time we see a human patient bleeding in a clinic, the virus has likely been circulating in the livestock population for weeks.

Cultural Crossroads: The High-Risk Intersection of Tradition and Pathogens

Effective public health must be a bridge, not a barrier. In Mauritius, the Eid-ul-Adha festival is a vital religious tradition involving the sacrifice of ruminants. However, from an epidemiological standpoint, it represents a high-risk intersection of human activity and potential pathogens. The process of slaughtering—severing the jugular veins and carotid arteries of a live animal—can result in "blood gushing out," creating a significant risk of infection through direct contact or aerosolized fluids.

The goal of modern surveillance is not to eliminate these traditions, but to shield the community through specific biosafety measures and the use of personal protective equipment (PPE) for those grooming and slaughtering. We have identified four primary risk factors during such large-scale events:

  • Uncontrolled animal movement across different districts and islands.
  • Crowding of humans and livestock in confined spaces.
  • Large-scale self-slaughter and traditional butchery outside regulated facilities.
  • Direct contact with infected blood, tissue, and amniotic fluid.

Mauritius’s Surprising Inhabitants: A Wild and Domestic Mosaic

Mauritius presents a unique host "mosaic" that complicates disease surveillance. While cattle and goats are common, they are dwarfed by a massive population of wild deer. This creates a complex bridge for emerging pathogens like Epizootic Haemorrhagic Disease (EHD). Historically a disease of wild ruminants—specifically deer—EHD is now an emerging threat in cattle. In an environment where 65,000 deer live in the same ecosystem as 4,000 cattle, the deer act as a massive, wild reservoir for viruses that can devastate the domestic dairy and beef industry.

The following headcount reflects the ruminant landscape as of 2025:

Species

Mauritius

Rodrigues

Sheep/Goat

26,000

26,000

Cattle

4,000

8,000

Deer

65,000

-

Despite its geographic isolation, Mauritius is an international hub, importing livestock from Kenya, South Africa, and Australia, as well as managing inter-island movement from Rodrigues and the regional context of La Reunion. Without a dedicated university for veterinary medicine, the island sits in a precarious position, relying on international partnerships to monitor the pathogens arriving at its shores.

Beyond the "Heartwater": The Complexity of Differential Diagnosis

One of the greatest challenges for island veterinarians is the "Diagnostic Challenge"—the fact that many vector-borne diseases (VBDs) look identical to the naked eye. Heartwater Disease (Ehrlichia ruminantium) and Anaplasmosis (often called "Gall Sickness") both present with high fever and depression.

In Heartwater, the pathogenesis is particularly striking: the pathogen multiplies within immune cells until they rupture, releasing organisms into the bloodstream and causing severe vasculitis. This inflammation of the blood vessels leads to "pericardial effusion"—a massive accumulation of fluid around the heart. To an observer, the animal may show "eyelid twitching," "protrusion of the tongue," or seizures.

Because the treatment for Heartwater (tetracyclines) differs from Anaplasmosis (imidocarbs), we cannot rely on broad-spectrum guesses. Active surveillance and targeted therapy are the only ways to prevent the rise of Antimicrobial Resistance (AMR). Using the wrong drug for a non-specific symptom doesn't just fail to save the animal; it strengthens the pathogens against our future medical arsenal.

The 2026 Pioneer Movement: Mapping the Future

To fill the void of missing statistics and outdated research, a landmark sampling mission is scheduled for February 2026. This pioneer movement aims to establish the first comprehensive, nationwide database of VBDs in Mauritius, spanning all 9 districts.

The framework is meticulously designed to pair specific vectors with the pathogens they carry:

  • Target Vectors: Collection of Hyalomma ticks (the primary vector for CCHF), Amblyomma ticks (the vector for Heartwater), Aedes and Culex mosquitoes (Rift Valley Fever), and Culicoides biting midges (Bluetongue and EHD).
  • Sample Size: 200–300 whole blood samples (EDTA) from cattle, sheep, and goats.
  • Methodology: Integration of an epidemiological questionnaire with high-accuracy diagnostic tools to identify transmission trends.

This study will finally bring the island to international standards, providing the data necessary to identify where these diseases are originating and how they are moving across the landscape.

Conclusion: The Cost of Isolation

In a globalized world, the concept of a "protected island" is a myth. The geographical distance that once served as a barrier now creates a dangerous silence. Without active surveillance, a pathogen can establish itself in the "wild mosaic" of the deer population or the silent reservoirs of the sheep pens long before the first human outbreak occurs.

Outbreak preparedness is not merely a scientific endeavor; it is an economic and humanitarian necessity. As we prepare for the 2026 survey, we must confront a sobering reality: our food systems and our health are only as secure as our surveillance of the invisible threads that connect us. If the silent ruminants of Mauritius are the sentinels of our future, are we finally ready to listen to what they are telling us?