– The leader of the Yersiniosis Monitoring Center, focused on diseases caused by Yersinia bacteria, outlines the center’s purpose since its opening in 2008. The center was established to advance surveillance, diagnostics, and research related to yersiniosis and its related conditions.
– Official registration of pseudotuberculosis and intestinal yersiniosis in Russia has continued for 29 years. Studies show that testing a relatively healthy population for antibodies specific to Yersinia would reveal their presence in roughly one in three people. This finding aligns with international research, since yersiniosis is found across many countries and on every continent except Antarctica. Since 1992, there has been an official separate record for these two diseases, combined under the broader term “yersiniosis.” Plague is also caused by Yersinia bacteria, but it is monitored by special anti-plague institutions within Rospotrebnadzor. When pseudotuberculosis and intestinal yersiniosis were first officially registered in the country, the epidemiological landscape looked quite different.
There were numerous sporadic cases and large outbreaks, especially of pseudotuberculosis. Today, the incidence is largely sporadic, consisting of individual cases rather than outbreaks from a single source.
– What is the current epidemiological situation of yersiniosis in Russia? Some medical literature notes that official statistics may underestimate true numbers due to diagnostic challenges, as many people do not seek care.
– The center does not influence statistics since data on yersiniosis are collected and published independently. Nonetheless, official numbers may not fully capture the reality, not from deliberate underreporting, but because yersiniosis presents with a wide range of clinical manifestations that can resemble many other infections. If the infection is not identified early, especially intestinal yersiniosis, its signs can fade over time.
In such cases, general somatic symptoms may dominate. A person might feel liver or joint discomfort without obvious infectious signs.
And the longer the illness lasts, often a month or more, the harder it is to recognize. Timely diagnosis is crucial. However, diagnosis is hampered by the varied clinical presentations and by the fact that the initial infection can appear mild and erased. Some patients experience mild gastrointestinal symptoms, followed by a sense of malaise and slight evening fever, leading many to delay medical consultation.
– Have epidemics disappeared for a long period?
– Between 2016 and 2020, group outbreaks were not recorded. In 2021 two major epidemics occurred in the Siberian Federal District. In January, 34 children at a Tomsk boarding school fell ill. In February, an outbreak in Krasnoyarsk affected students from 27 schools, totaling 114 cases. Investigations were conducted with active participation from authorities, including fieldwork in Krasnoyarsk as part of a commission. Since early 2022, there have been no recognized outbreaks of yersiniosis.
Yersiniosis and pseudotuberculosis are caused by different bacteria within the same genus. How do their disease courses differ?
Both conditions share many clinical features. Clinicians face the challenge of distinguishing them. With pseudotuberculosis and intestinal yersiniosis, gastrointestinal tract involvement and systemic poisoning are possible. Pseudotuberculosis more commonly presents with a distinctive rash along body folds, arms, and legs, followed by peeling. In contrast, intestinal yersiniosis typically begins with gastroenteritis symptoms, may progress to an acute intestinal infection, and can involve systemic signs of intoxication and multi-organ involvement. Diagnosis plays a central role in differentiating them.
– Are there diagnostic challenges for Yersiniosis? It is true that its symptoms can mimic other conditions.
– Diagnostic challenges exist. Even with a thorough patient history, clinical signs alone cannot confirm pseudotuberculosis or intestinal yersiniosis. There are no highly specific symptoms, which makes timely diagnosis difficult. Nevertheless, clinicians may suspect yersiniosis and order appropriate tests when needed.
Of course, self-diagnosis is not reliable. Yersiniosis often begins with common gastrointestinal symptoms. If issues persist or general malaise and low-grade fever appear over time, a patient should seek assessment from an infectious disease specialist or a gastroenterologist. Self-medication is not advised. Yersiniosis is primarily treated with antibiotics.
– Can the immune system cope with these infections on its own?
– The outcome depends on the person’s immune status and the pathogen dose. Research indicates that about a third of people encountered the causative agents in their lifetime, though many recover without ongoing symptoms, possibly after minimal treatment.
Are there risk groups? For instance, people in close contact with animals or handling raw foods?
– Risk groups include those in animal husbandry, poultry farming, and workers in vegetable handling, food processing, and related facilities. Transmission varies: pseudotuberculosis is often linked to contaminated vegetable products such as fresh cabbage, onions, and carrots, while intestinal yersiniosis is more commonly tied to meat, dairy, and poultry products eaten raw or insufficiently cooked.
It is important to note that contaminated products can harbor Yersinia for extended periods in refrigerator conditions (4 °C). Pseudotuberculosis is frequently associated with salads made from fresh vegetables that are contaminated and stored after low-temperature cooking. Children are a high-risk group, with outbreaks more common in organized groups where children predominate in the population.
– How has the situation improved regarding diagnosis, treatment, and prevention since the center was established?
– The center continually explores new diagnostic methods and strives to improve the accuracy of yersiniosis diagnosis. One advanced technique is the immunoblot method, which detects antibodies to specific pathogen antigens via enzyme immunoassay on nitrocellulose membranes. This approach provides high specificity and sensitivity and has been in use for diagnostic purposes since 2015, with positive feedback from clinicians.
– Is there a typical season for yersiniosis outbreaks?
– Intestinal yersiniosis can occur in any season. Pseudotuberculosis tends to show autumn-winter seasonality, though spring and summer periods can also see increases, albeit less pronounced.
What are the main prevention strategies for Yersiniosis?
– The primary reservoirs are rodents living in rural areas and urban settings, including field mice, voles, house mice, and rats, which can contaminate food. For pseudotuberculosis, thorough washing of vegetables, fruits, and greens is essential. For intestinal yersiniosis, careful handling of meat products and thoroughly cooking semi-finished and finished products is crucial. Undercooked pork and some dairy products, especially from non-industrial sources, pose risks. A wide range of foods can be involved. Raw and cooked foods, bread, and dairy should be prepared with separate cutting boards and utensils. Water from open sources should not be consumed.
– How effective is treatment and what complications can arise?
– Most cases respond well to treatment, especially when diagnosed early during the acute stage. Pseudotuberculosis and intestinal yersiniosis may have an acute course lasting up to one month, a prolonged course up to three months, or a chronic course of six months or longer. Some patients endure chronic infection for years. Even then, treatment can be successful, though chronic infections may present with erythema nodosum, reactive arthritis, or chronic enterocolitis. Diagnosing chronic cases is challenging, as stool testing becomes less informative and blood tests for specific antibodies, including immunoblot testing, become essential for confirmation and monitoring.