Introduction
The PREPARE-TID consortium is building one of Europe’s first coordinated zoonotic surveillance networks, linking veterinary, medical, and environmental diagnostics across Southeastern Europe. By connecting fieldwork, laboratory capacity, and cross-border data-sharing, the network aims to catch emerging threats at the animal–human interface before they spill over. Learn more about the PREPARE-TID Network (here).
Europe’s efforts to prevent the next pandemic often focus on novel viruses, global travel, and high-profile zoonotic spillovers. Yet beneath this visible layer lies a spectrum of bacterial zoonoses that persist, undetected and underreported, across regions like the Western Balkans. Here, the ecological interface between animals and humans—fueled by agricultural practices, insufficient diagnostics, and increasing wildlife contact—creates a fertile ground for endemic transmission and silent spread.
Unlike emerging pathogens that grab headlines, bacterial zoonoses such as Brucella canis, Coxiella burnetii, and Leptospira spp. often present with non-specific symptoms, are poorly surveilled, and are rarely confirmed in standard diagnostics. This silence is deceptive. When pathogens go undetected in veterinary reservoirs and spill into human populations, the diagnostic delay can cost lives.
At the heart of this vigilance is Dr. Tamaš Petrović, Head of the Department for Diagnostics and Research at the Scientific Veterinary Institute "Novi Sad" in Serbia. During the July 23, 2025 PREPARE-TID webinar, he delivered a powerful message: despite being largely absent from national reporting dashboards, bacterial zoonoses are thriving—and diagnostics must catch up fast.
Mapping the Microbial Landscape: Petrović’s Molecular Surveillance Strategy
Dr. Petrović began by outlining a sobering reality: “We no longer have the luxury of treating these as sporadic or forgotten pathogens. They are part of the endemic landscape now.”
His team has investigated more than 4,300 diagnostic samples from farm animals, wildlife, and companion animals between 2021 and 2025. Geographically, the institute’s network covers more than 70 municipalities, making it one of the few sources of longitudinal data on pathogen prevalence in the region and leverages a combined approach using qPCR, ELISA, culture, and sequencing.
Their sample work includes:
- 2,100+ livestock samples tested via qPCR and culture for Brucella spp.
- 900+ tick pools screened using multiplex PCR for Borrelia, Rickettsia, Anaplasma, and Coxiella
- 620 rodent tissue and urine samples, with over 18.4% PCR-positive for Leptospira spp., and 6.2% for C. burnetii
- 440 aborted fetal tissue samples, identifying C. burnetii as the most frequent agent (confirmed in 27.5% of samples), followed by Brucella abortus (12.3%)
“Our teams are actively using multiplex PCR and sequencing to confirm Brucella, Coxiella, and Borrelia in sentinel samples,” Petrović explained. “The goal is not just to identify, but to anticipate.”
Petrović’s team is at the forefront of applied field diagnostics in Serbia:
- Differentiating Brucella species using real-time PCR targeting bcsp31 and IS711 insertion elements
- 16S rRNA metagenomic sequencing for detection of uncultivable or unexpected pathogens in tick and rodent samples
- RT-PCR panels for bovine and ovine abortion diagnostics—applied to samples from 54 farms
- Pilot deployment of mobile qPCR devices, such as battery-powered thermal cyclers and magnetic extraction kits, in 12 under-resourced rural labs
This decentralized capacity has shortened diagnostic turnaround from 7–10 days to less than 24 hours in outbreak-prone areas.
“We’re working toward a model where the delay between suspicion and confirmation is a matter of hours—not weeks,” he added.
Wildlife and Vector-Based Sampling as Predictive Epidemiology
Vector surveillance is often considered supplementary, but for Petrović, it’s central to understanding what pathogens are truly circulating.
One striking example comes from tick surveillance. Ticks are collected from both humans and wildlife in the field and serve as sentinel indicators of circulating pathogens.
Between 2022 and 2024, his team collected and processed:
- 3,200 ticks from humans, of which 33.2% tested positive for Borrelia burgdorferi s.l. via qPCR (OspA and FlaB gene targets)
- 1,100 field-captured ticks, showing regional positivity rates from:
- 10.4% (Central Serbia, mixed forests)
- Up to 28.1% (Vojvodina lowlands and woodlands)
- 620 rodents, sampled near urban farms and water reservoirs:
- Leptospira spp. detected in 18.4%
- Coxiella burnetii in 6.2%
- Co-infections confirmed in 3.9%, particularly in Mus musculus and Rattus norvegicus species
One particularly notable finding: ticks from dogs imported from endemic regions (Bosnia, Albania) showed higher positivity for Rickettsia slovaca and Borrelia afzelii—suggesting pet movement is a pathway for vector-borne zoonoses.
“We use ticks as a proxy for environmental risk. What they carry is often more informative than isolated clinical cases,” he explained. “They give us early warning.”
This data, while deeply regional, mirrors larger One Health principles. Wildlife, vectors, and livestock do not transmit disease in isolation—they exist in intersecting ecologies. By integrating data from all these sources, the Novi Sad lab has pioneered what may be one of the most functionally operational One Health surveillance systems in Europe.
From qPCR to Whole Genomes: How Regional Labs Are Scaling Up
The surveillance operation runs with a semi-automated laboratory pipeline:
- Magnetic bead-based extraction (KingFisher and SwiftX™ Virus kits)
- qPCR on StepOnePlus and Bio-Rad CFX systems
- Sanger sequencing for 16S and gltA genes
- Illumina MiSeq and Oxford Nanopore for targeted metagenomics
Across the past 24 months, the team has completed:
- 308 sequencing runs, targeting Borrelia, Leptospira, and Brucella isolates
- Assembled 34 draft genomes of Leptospira interrogans from rodents and canine carriers from clinical and environmental isolates. This genomic layer allows epidemiologists to differentiate between strains introduced from abroad and those circulating locally for decades.
- Genotyped Coxiella burnetii strains from 11 ruminant abortions using MLVA and IS1111 qPCR
“We can now link wildlife isolates to human clusters through genomics,” Petrović said. “This kind of evidence moves diagnostics from reactive to predictive.”
Such data-driven vigilance offers more than insight—it lays the groundwork for outbreak prevention. But as Petrović noted, the full impact of this work hinges on scale-up and integration into public health infrastructure. Without standardized protocols and cross-sectoral reporting, diagnostic findings often remain siloed.
In his words: “Surveillance only works when it’s institutionalized. Right now, it relies on motivated teams and project funding. That’s not sustainable.”
> Continue to Part II
Take your diagnostics to the next level
- Request a SwiftX™ Virus trial kit – now available as CE-IVD – or protocol walkthrough (here)
- Watch the full Episode 2 of our PREPARE-TID webinar recording on YouTube (here)
- If you would like to collaborate with us, contact us (here)