Giardiasis (lambliasis) in Poland in 2020.

OBJECTIVE: Assessment of the epidemiological situation of giardiasis in Poland in year 2020. MATERIAL AND METHODS: The assessment of the epidemiological situation of giardiasis in Poland in 2020 was performed on the basis of aggregated data from the annual bulletins "Infectious diseases and poisoning in Poland" for the years 2006-2020, data on individual cases collected for the purposes of epidemiological surveillance in the EpiBaza system, and data from food-borne outbreak investigations recorded in the Registry of Epidemic Outbreaks (ROE). RESULTS: The number of new cases of giardiasis reported in Poland in 2020 amounted to 358 cases (incidence rate 0.9 per 100,000 population) and was about 2 times lower than in 2019 (784 cases) and 2.5 times lower than in 2018 (928 cases). In 2020, there was a further decrease in the number of registered cases, but it was much more pronounced than in the preceding years. As in previous years, no deaths from giardiasis were recorded. The downward trend in hospitalizations continued and in 2020 they accounted for approximately 12.6% of all cases, in 2019 the percentage was 15.2% and in 2018 - 19.4%. Most cases met the definition of a confirmed case, with 1 patient meeting the criteria of a probable case. In 2020, 6 outbreaks of giardiasis were reported, which is a decrease compared to 2019 (12 outbreaks) and thus means a reversal of the upward trend occurring at least since 2017. CONCLUSIONS: Data for 2020 should be interpreted taking into account the effect of the COVID-19 pandemic, which could have resulted in changes in long-term trends, but in particular contributed to a strong decrease in the number of cases not only of giardiasis, but also of other infectious diseases. In 2020, almost all EU/EEA countries reported a decrease in the incidence of giardiasis similar to that in Poland. However, as in 2019, in 2020 Poland differed from other EU/EEA countries in terms of incidence by age and sex.

Reactive Arthritis Update: Spotlight on New and Rare Infectious Agents Implicated as Pathogens.

PURPOSE OF REVIEW: This article presents a comprehensive narrative review of reactive arthritis (ReA) with focus on articles published between 2018 and 2020. We discuss the entire spectrum of microbial agents known to be the main causative agents of ReA, those reported to be rare infective agents, and those reported to be new candidates causing the disease. The discussion is set within the context of changing disease terminology, definition, and classification over time. Further, we include reports that present at least a hint of effective antimicrobial therapy for ReA as documented in case reports or in double-blind controlled studies. Additional information is included on microbial products detected in the joint, as well as on the positivity of HLA-B27. RECENT FINDINGS: Recent reports of ReA cover several rare causative microorganism such as Neisseria meningitides, Clostridium difficile, Escherichia coli, Hafnia alvei, Blastocytosis, Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica/dispar, Strongyloides stercoralis, ß-haemolytic Streptococci, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Mycobacterium bovis bacillus Calmette-Guerin, and Rickettsia rickettsii. The most prominent new infectious agents implicated as causative in ReA are Staphylococcus lugdunensis, placenta- and umbilical cord-derived Wharton's jelly, Rothia mucilaginosa, and most importantly the SARS-CoV-2 virus. In view of the increasingly large spectrum of causative agents, diagnostic consideration for the disease must include the entire panel of post-infectious arthritides termed ReA. Diagnostic procedures cannot be restricted to the well-known HLA-B27-associated group of ReA, but must also cover the large number of rare forms of arthritis following infections and vaccinations, as well as those elicited by the newly identified members of the ReA group summarized herein. Inclusion of these newly identified etiologic agents must necessitate increased research into the pathogenic mechanisms variously involved, which will engender important insights for treatment and management of ReA.