Search Results (1,167)

Lyme borreliosis (LB) is a tick-borne disease caused by a diverse and expanding group of spirochetes characterized by complex biology and advanced immune evasion mechanisms. It presents a wide range of clinical symptoms affecting multiple organ systems and can lead to persistent complications. The pathogenesis of LB remains incompletely understood, and diagnosis typically relies on serologic assays to detect antibodies against LB. However, the standard two-tiered testing (STTT) algorithm is limited by cross-reactivity, low sensitivity, and delayed results, hindering timely and accurate diagnosis. Although molecular tests are considered the gold standard, their reliance on centralized laboratories can delay critical treatment decisions. This underscores the urgent need for rapid, reliable diagnostic tools, particularly for use at the point of hospital admission. Point-of-care serological and direct antigen testing can provide actionable information, supporting decentralized healthcare systems in diagnosing complex diseases, such as LB. In this study, we developed two fluorescent polarization immunoassays (FPIAs) using IgM and IgG LB-specific synthetic epitopes/peptides to evaluate their diagnostic potential. These FPIAs showed high sensitivity and specificity in detecting IgM or IgG anti-LB antibodies in patient sera within minutes. The fluorescently labeled synthetic peptides produced significant polarization differences between infected and healthy samples, allowing clear discrimination. The FPIA-LB functions as a one-step assay, eliminating the need for secondary antibodies or complex protocols. This work highlights the FPIA technique as a robust, rapid, and efficient tool for LB diagnosis, offering a promising advance in improving early detection and patient outcomes, which could save lives and reduce long-term health complications. Full article

Brucella canis is a recognized zoonotic pathogen associated with human infection in a variety of epidemiological settings; however, the magnitude of its impact on human health remains uncertain because of its nonspecific clinical presentation, limited availability of species-specific diagnostic methods, and insufficient awareness among physicians, veterinarians, microbiologists, and public health professionals. Unlike classical human brucellosis caused by smooth Brucella species, B. canis infection may be overlooked, potentially leading to delayed diagnosis and incomplete case detection. This narrative review summarizes current evidence on the epidemiology, transmission pathways, occupational and non-occupational risk factors, clinical manifestations, diagnostic approaches, treatment, and public health implications of human B. canis infection. Particular emphasis is placed on published human cases, laboratory-acquired infections, household clusters, cases reported in different age and immune-status groups, and the biological and epidemiological characteristics of canine infection that facilitate zoonotic transmission. The review further examines the limitations of currently available microbiological, serological, and molecular diagnostic methods, the lack of harmonized surveillance systems, and the consequences of inadequate recognition from a One Health perspective. Collectively, the available evidence confirms the zoonotic potential of B. canis but remains insufficient to define the true burden of human infection. Improving clinical awareness, strengthening collaboration between veterinary and human health sectors, expanding access to standardized diagnostic tools, and implementing integrated One Health surveillance may improve recognition and reduce zoonotic risk. Full article

Background: Myasthenia gravis is an autoimmune disorder of the neuromuscular junction characterized by fluctuating skeletal muscle weakness. Late-onset MG (onset ≥ 50 and <65 years) and very late-onset MG (VLOMG; onset ≥ 65 years) are increasingly recognized subgroups, and diagnosis in very elderly patients remains challenging because symptoms frequently overlap with age-related conditions and comorbidities. Case Presentation: An 88-year-old man with very late-onset myasthenia gravis (symptom onset at approximately age 85) was urgently referred because of a several-day history of rapidly worsening dysphagia and dysarthria, superimposed on fluctuating diplopia, dysphagia, dysarthria, and fatigable bulbar symptoms that had progressively worsened over the preceding three years. Initial diagnostic evaluation was challenging because of advanced age, previous lacunar infarctions, and multiple comorbidities, including pulmonary thromboembolism, chronic kidney disease, and permanent pacemaker implantation (which precluded brain MRI). Neurological examination and the characteristic fluctuation of symptoms raised suspicion of myasthenia gravis. Serological testing confirmed markedly elevated acetylcholine receptor antibodies, whereas MuSK antibodies were negative. Repetitive nerve stimulation was not performed given the high antibody titer and unambiguous clinical presentation. Thoracic computed tomography excluded thymoma. Treatment with pyridostigmine, azathioprine (maintenance dose kept lower than standard due to chronic kidney disease stage IIIB), and low-dose prednisone (selected due to age and comorbidity profile) resulted in early, patient-reported clinical improvement (approximately 60% in speech and swallowing) over eight weeks of follow-up; a validated severity scale (MG-ADL) showed a score of six (scoring range 0–24). Conclusions: Myasthenia gravis should remain an important differential diagnosis in very elderly patients presenting with fluctuating ocular and bulbar symptoms, even in the presence of multiple comorbidities that may obscure the diagnosis. In this patient, early recognition, antibody testing, and individualised initiation of therapy were followed by meaningful short-term improvement; a single case with eight weeks of follow-up cannot establish that such therapy prevents disease progression or myasthenic crisis, and longer follow-up and additional cases are needed. Full article

Background: Chikungunya virus (CHIKV) is a mosquito-borne alphavirus transmitted predominantly by Aedes aegypti and Aedes albopictus. Infection is characterized by an acute febrile illness accompanied by debilitating polyarthralgia, myalgia, and cutaneous manifestations. Although the acute syndrome is usually self-limited, a substantial proportion of patients experience persistent musculoskeletal symptoms that may progress to chronic inflammatory arthritis, resulting in prolonged disability and impaired quality of life. Objective: To summarize current evidence on the epidemiology, virology, immunopathogenesis, clinical manifestations, laboratory diagnosis, prevention, and vaccine development of CHIKV, with particular emphasis on its implications for public health policy and immunization strategies in Mexico. Methods: This position paper was developed through a structured narrative review of the scientific literature. Publications indexed in PubMed, Scopus, and Embase, together with documents issued by the World Health Organization (WHO), Pan American Health Organization (PAHO), Centers for Disease Control and Prevention (CDC), U.S. Food and Drug Administration (FDA), and European Medicines Agency (EMA), were critically reviewed. Evidence was selected according to its scientific quality and relevance to Mexico and Latin America. Because this work represents an expert consensus rather than a systematic review, no formal risk-of-bias assessment was performed. Results: CHIKV circulates through both urban and sylvatic transmission cycles and continues to expand into regions where competent mosquito vectors are established. Disease progression is driven by complex innate and adaptive immune responses, with exaggerated inflammatory activation contributing to chronic rheumatologic sequelae. Laboratory confirmation relies primarily on molecular assays during the viremic phase and serological testing thereafter. Recent advances in vaccine development—including live-attenuated and virus-like particle (VLP) platforms—have demonstrated favorable immunogenicity and acceptable safety profiles. However, vaccination should be considered one component of an integrated prevention strategy that also includes vector surveillance, environmental control, and rapid outbreak detection. Conclusions: Chikungunya remains an emerging global public health challenge because of its expanding geographic distribution, epidemic potential, and long-term clinical consequences. Incorporating vaccination into comprehensive arboviral control programs, together with strengthened surveillance and integrated vector management, may substantially reduce disease burden. This position paper provides evidence-based recommendations to support future chikungunya prevention and vaccination policies in Mexico. Full article

Gastric cancer remains a major cause of cancer mortality worldwide, mainly due to its frequent diagnosis at advanced stages and the high probability of recurrence even after curative treatment. Conventional postoperative follow-up is mainly based on imaging studies, endoscopy and serological tumor markers, such as carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 72-4 (CA72-4)This narrative review was based on a structured literature search of PubMed, Scopus, Web of Science, MEDLINE, the Cochrane Library, and ClinicalTrials.gov from database inception through June 2026, with 75 studies included in the final narrative synthesis. Among these analytes, circulating tumor DNA (ctDNA)currently provides the most mature data for the detection of molecular residual disease and postoperative risk stratification. Although it allows for the early detection of recurrent or residual disease prior to imaging confirmation, postoperative ctDNA has shown significant prognostic value in many studies; however, routine use as a basis for decision-making in treatment planning is still considered investigational and will require future prospective clinical validation. Tumor-informed ctDNA approaches offer high analytical specificity and sensitivity in low-burden disease settings. In contrast, tumor-agnostic approaches, such as methylation analysis and fragmentomics, may improve the scalability of the method. However, they require further validation in the postoperative setting. At the same time, emerging data indicate that extracellular vesicles, exosomal RNA and peritoneal lavage analytes can provide complementary biological information, especially in cases of peritoneal dissemination. Despite the significant prospects, the use of liquid biopsy in guiding the treatment of gastric cancer remains under investigation. This is because even today there are limitations. Characteristic are the low ctDNA excretion and the anatomical heterogeneity of the disease, as well as clonal hematopoiesis. Limitations also include the lack of standardization as well as the cost and the need for prospective clinical studies. This review summarizes the biological basis of molecular residual disease, liquid biopsy technologies, ctDNA data, the concept of molecular recurrence, and the future prospects of multi-analytic and artificial intelligence (AI)-assisted surveillance models in gastric cancer. Full article

Background/Objectives: The relationship between large-scale natural disasters and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) remains uncertain. This study compared crude case numbers, diagnostic patterns, and clinical characteristics of newly diagnosed AAV before and after the 6 February 2023 Kahramanmaraş earthquakes in Türkiye. Methods: This multicenter retrospective study included patients newly diagnosed with AAV between 6 February 2020 and 5 February 2026 at five tertiary referral centers in four provinces heavily affected by the earthquakes. Equal 36-month pre- and post-earthquake periods were compared. Demographics, AAV subtype, ANCA serology, biopsy-confirmed diagnosis, organ involvement, Birmingham Vasculitis Activity Score (BVAS), laboratory findings, treatments, and recorded outcomes were evaluated. Results: A total of 127 patients were included: 58 (45.7%) before and 69 (54.3%) after the earthquakes. The crude number of cases was numerically higher after the earthquakes, but the difference was not statistically significant (p = 0.375). AAV subtype, ANCA serology, organ involvement, BVAS, inflammatory markers, renal function, and most laboratory findings were comparable. Biopsy-confirmed diagnoses were significantly less frequent in the post-earthquake period than in the pre-earthquake period (46.4% vs. 70.7%, p = 0.010). Treatment patterns were comparable between the two periods. Although the crude proportions of recorded outcomes did not differ significantly, these comparisons were limited by the substantially shorter follow-up duration in the post-earthquake group and should not be interpreted as evidence of comparable prognosis. Conclusions: In major tertiary referral centers serving earthquake-affected provinces, crude AAV case numbers and baseline clinical phenotypes were largely comparable before and after the earthquakes. These crude case numbers should not be interpreted as incidence estimates, because reliable population denominators were unavailable after the earthquakes. The significant reduction in biopsy-confirmed diagnoses may reflect post-disaster changes in diagnostic healthcare pathways. These real-world data provide an important regional overview of newly diagnosed AAV after a major natural disaster. Full article

Background: Rift Valley fever (RVF) is a livestock-amplified, mosquito-borne zoonosis caused by Rift Valley fever virus (RVFV). Continental Europe has no established RVFV transmission, but a rare introduction could have major consequences if susceptible ruminants amplify infection before detection. Methodology: This critical narrative review synthesizes 69 scientific and institutional sources identified through structured PubMed/MEDLINE and Europe PMC searches, citation verification, and qualitative appraisal. Findings: European preparedness should distinguish probability from impact and weight evidence by decision value. Direct virological or acute animal evidence has the highest escalation value; serology, vector competence, environmental suitability, and pathway models mainly indicate where investigation should intensify. The main vulnerability is delayed recognition when animal movement or transported vector exposure coincides with seasonal receptivity and uneven surveillance capacity. Conclusions: The review develops a conditional convergence framework linking evidence strength to baseline vigilance, targeted investigation, and emergency response. Preparedness should prioritize differential diagnosis of livestock abortions and neonatal deaths, pathway-specific risk reduction, trigger-based sampling, occupational protection, and predefined vaccination and movement control decisions. Full article

Chagas disease is difficult to diagnose in the chronic phase, especially when serological assays disagree. We examined whether Trypanosoma cruzi metacyclic trypomastigotes’ antigenic extracts may increase ELISA/Western blot concordance in initially discordant serum compared to epimastigotes. A total of 178 human blood samples were studied, including seropositive persons, Chagasic cardiomyopathy patients, discordant sera, seronegative controls, and sera from various parasitic illnesses. Antigenic extracts from epimastigotes and metacyclic trypomastigotes were extracted using sonication or urea, and Western blot and ELISA were used to compare their behavior. Sonicated metacyclic trypomastigote extracts produced concordant ELISA/Western blot results in 31/35 originally discordant sera, compared to 19/35 for sonicated epimastigotes, 20/35 for urea-extracted trypomastigotes, and 17/35 for urea-extracted epimastigotes. All extracts in the serum panel previously classified using the standardized in-house serological platform showed 100% positive percent agreement, but negative percent agreement varied between 93.3% for sonicated metacyclic trypomastigotes and 66.7% for urea-extracted epimastigotes. These estimates reflect agreement with the previous serological classification, not diagnostic accuracy versus an independent reference standard. Cross-reactivity was mainly observed in sera from patients with leishmaniasis, while sera from the cardiopathic group showed an exploratory preferential recognition pattern with bands of 18, 22, 24, and 26 kDa in the sonicated metacyclic trypomastigote preparation. The comparison did not account for potential clinical variables or molecularly identify these bands. These data demonstrate that stage-informed antigen selection, particularly using sonicated metacyclic trypo-mastigote extracts, can affect serum panel assay concordance and nonspecific reactivity. Full article

Strangles, caused by Streptococcus equi subsp. equi (S. equi), is a highly contagious respiratory disease that causes substantial economic losses to the horse industry worldwide. Serological diagnosis currently relies mainly on the imported IDvet^® dual-antigen sandwich ELISA kit, which shows good diagnostic performance but is expensive and lacks a domestic alternative in China, thereby limiting its routine use in primary veterinary settings. The aim of this study was to develop a domestic indirect ELISA based on novel antigen targets and an untagged antigen purification strategy. Using comparative bioinformatics analyses, two conserved fragments with species-level specificity for S. equi, designated EQ8 (150 aa) and SclF (44 aa), were identified and fused for recombinant expression. The fusion protein was purified by GST affinity chromatography, cleaved with PreScission protease, and subjected to secondary purification to obtain an untagged EQ8–SclF protein. Western blotting and ELISA demonstrated that the purified protein retained good immunoreactivity and that the GST tag did not cause detectable cross-reactivity, with all OD₄₅₀ values obtained using GST-coated plates remaining below 0.09, well under the cut-off value of 0.115. Checkerboard titration established the optimal assay conditions as an antigen coating concentration of 1 μg/mL and a serum dilution of 1:100. Using the IDvet kit as the reference method, 157 clinical serum samples (67 positive and 90 negative) were tested in parallel. The newly developed assay showed a relative sensitivity of 89.55% (60/67), a relative specificity of 94.44% (85/90), an overall agreement rate of 92.36% (145/157), and a kappa value of 0.84, indicating excellent agreement between the two methods. Good inter-assay reproducibility was observed, with coefficients of variation all below 9.29%. In conclusion, an indirect ELISA based on an untagged EQ8–SclF fusion protein was preliminarily established for the serological detection of strangles. This assay showed diagnostic performance highly consistent with that of the imported commercial kit while offering potential advantages in terms of lower cost, simpler operation, and elimination of tag-associated interference. It therefore shows potential as a domestic alternative for the serological diagnosis of strangles. Full article

Leishmaniasis is an emerging zoonotic disease recognized by WHO as a priority neglected tropical disease (NTD) targeted for elimination by 2030. The disease is transmitted through bites of infected female phlebotomine sand flies and presents in three main forms: cutaneous, mucocutaneous, and visceral leishmaniasis. Visceral leishmaniasis (VL) has two distinct epidemiological cycles: anthroponotic visceral leishmaniasis (AVL) cycle, caused by L. donovani and transmitted between humans, and zoonotic visceral leishmaniasis (ZVL) cycle, caused by L. infantum, with domestic dogs as the main reservoirs. ZVL represents the most severe clinical form and poses a public health risk due to a high fatality rate. In Kenya, the epidemiology and transmission dynamics of Leishmania infection among the canine population in endemic areas such as Baringo are poorly characterized. A cross-sectional epidemiological study was conducted in Baringo County, Kenya, one of the endemic foci for human visceral leishmaniasis. Blood samples were collected from 140 dogs in Rabai, Sabor, Mbechot, Kapkuikui, and Chemolingot and analyzed using Rapid Diagnostic Test (RDT) and Enzyme-linked immunosorbent assay (ELISA). Data on potential epidemiological factors and clinical status for dogs were collected using a questionnaire. Statistical analysis was performed using Pearson’s chi-square (χ²) test or Fisher’s exact test to assess associations between Leishmania seropositivity and potential risk factors. A stepwise logistic regression procedure with an entry significance level of p < 0.20 was employed to identify factors associated with leishmaniasis seroprevalence. Cohen’s kappa (κ) agreement was used to assess the diagnostic performance and accuracy of the two serological tests in the absence of a gold standard. The overall seropositivity in dogs was 7.79% and 12.14% at 95% CI for the RDT and ELISA, respectively. Multivariate analysis identified breed and clinical signs as significant factors associated with Leishmania seropositivity in dogs. Local-breed dogs were more likely to be Leishmania seropositive than mixed-breed dogs (OR = 11.92; 95% CI: 1.79–79.37; p = 0.010). Dogs without clinical signs exhibited significantly lower odds of ELISA seropositivity (OR = 0.06; 95% CI: 0.01–0.29; p < 0.001). Dogs with proper care and housing conditions had reduced risk of Leishmania seropositivity compared with poorly managed dogs. Significant association with seropositivity was observed for sex, age, origin, and reason for keeping dogs. Diagnostic evaluation showed that the RDT had an excellent specificity and Positive Predictive Value (100%), with good overall agreement with ELISA, although sensitivity was 64.7%. Hence, RDT can be a reliable alternative screening tool compared with ELISA as the reference standard. The study demonstrated the presence of Leishmania infection in the dog population in Baringo County, Kenya, a significant public health risk. Early detection and diagnosis of infections in dogs through an integrated One Health approach during routine surveillance are essential. This will facilitate treatment and/or culling of infected dogs and vector control, subsequently reducing the risk of human transmission. Hence, it will go a long way to achieving WHO’s roadmap of eliminating leishmaniasis by 2030. Full article

Background/Objective: Bartonella henselae, the causative agent of cat-scratch disease (CSD), usually causes a self-limiting zoonotic infection. Osteomyelitis is a rare but increasingly recognized manifestation, particularly in children, and may closely mimic malignant or other infectious bone diseases. We present a case of multifocal pediatric Bartonella henselae osteomyelitis and discuss the associated diagnostic and therapeutic challenges in the context of the current literature. Case presentation: We report the case of a previously healthy 10-year-old girl who presented with a one-month history of fever, fatigue, limping, and progressive thigh and groin pain following cat-scratch exposure. During the course of the illness, she developed unilateral facial nerve palsy and Parinaud oculoglandular syndrome. Initial laboratory investigations demonstrated elevated inflammatory markers and reactive thrombocytosis. Serological testing for Bartonella henselae was positive for both IgM and IgG antibodies, whereas polymerase chain reaction (PCR) testing of both peripheral blood and the bone biopsy specimen was negative. Plain radiographs were unremarkable; however, magnetic resonance imaging (MRI) revealed multifocal lesions involving the right femoral diaphysis, right pubic bone, and left iliac wing, together with focal hepatic and splenic lesions suggestive of disseminated disease. Because of the radiological suspicion of malignancy, a femoral bone biopsy was performed and demonstrated osteomyelitis with necrosis and microabscess formation, without evidence of malignancy. Following targeted antimicrobial therapy, the patient showed rapid clinical and laboratory improvement, with progressive regression of the lesions on follow-up MRI. Conclusions: Bartonella henselae osteomyelitis should be considered in the differential diagnosis of multifocal bone lesions in children, particularly in patients with a history of cat exposure. Because the disease may closely mimic malignancy both clinically and radiologically, establishing the diagnosis requires careful integration of epidemiological, clinical, serological, radiological, molecular, and histopathological findings. Early recognition and appropriate antimicrobial treatment are associated with an excellent prognosis. Full article

A 66-year-old man with hypertension, type 2 diabetes mellitus, and a 50-year smoking history was presented with acute chest pain clinically consistent with unstable angina. Coronary computed tomography angiography (CCTA) showed multivessel atherosclerosis and, more strikingly, diffuse sheath-like pericoronary soft-tissue cuffing around the major epicardial arteries—an appearance reported as the “mistletoe sign” and compatible with immunoglobulin G4 (IgG4)-related coronary periarteritis. CT-derived fractional flow reserve (CT-FFR) measured 0.75 in the left anterior descending artery, 0.68 in the left circumflex artery, and 0.94 in the right coronary artery. Invasive angiography identified a 90% proximal left circumflex stenosis as the flow-limiting lesion; drug-eluting stent implantation restored Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow. Serum IgG4 (145 mg/dL) was only marginally above the diagnostic threshold, and troponin was unavailable, so the diagnosis remained clinical. Without histopathology, the findings support possible rather than definite IgG4-related disease, and the contribution of the pericoronary process to the stenosis could not be established. The patient remained stable on conventional medical therapy. CCTA, CT-FFR, and angiography answer complementary questions; diffuse pericoronary change warrants serologic and systemic evaluation for inflammatory coronary involvement, with cautious etiologic attribution. Full article

Autochthonous mucocutaneous leishmaniasis caused by Leishmania infantum is an under-recognised but established manifestation of endemic leishmaniasis in Spain. This review identified 65 confirmed autochthonous cases reported since 1990, showing a relatively consistent clinical pattern. Most patients were adults, predominantly men in the fifth or sixth decade of life. Nearly half were immunosuppressed, mainly due to HIV infection, corticosteroid use, biologic therapy, autoimmune diseases, or solid organ transplantation, although immunocompetent individuals were also affected. The laryngeal, nasal, and oral mucosa were the most commonly involved sites, with occasional tracheal and bronchial disease. Clinical presentation was typically chronic and non-specific, including ulcerative, nodular, polypoid, or tumour-like lesions that frequently mimicked malignancy or inflammatory disorders, often delaying diagnosis. Unlike classical New World mucocutaneous leishmaniasis, Spanish cases generally lacked a preceding cutaneous lesion, supporting recognition as a distinct form of L. infantum infection. Diagnosis required microbiological confirmation, ideally with species identification through culture or molecular methods, while serology showed limited reliability. Treatment approaches varied considerably, reflecting the absence of standardised protocols, although systemic therapy (particularly liposomal amphotericin B) was most commonly used. Improved recognition, surveillance, and inclusion in clinical guidelines are needed to reduce diagnostic delay and therapeutic variability. Full article

This case report highlights how neglected tropical diseases (NTDs) may remain underdiagnosed in high-resource settings despite advanced healthcare systems. We describe an 18-year-old woman from Equatorial Guinea living in Spain who presented with chronic pruritus and episodic ocular symptoms and was ultimately diagnosed with ocular loiasis after the incidental extraction of a conjunctival filaria. Diagnostic evaluation included microscopy, serology, and molecular techniques, confirming Loa loa and Mansonella perstans co-infection alongside evidence of exposure to other parasitic infections. Management involved staged antiparasitic therapy with albendazole, ivermectin, praziquantel, and diethylcarbamazine, combined with corticosteroids to mitigate treatment-related reactions. The patient showed clinical improvement, although follow-up was irregular and microfilaremia persisted. This case illustrates key challenges in non-endemic settings, including low clinical suspicion, fragmented care pathways, and barriers to healthcare access among migrant populations. Despite the availability of sensitive diagnostic tools, delayed recognition remains common when tropical diseases are not considered in the differential diagnosis. Comprehensive, multidisciplinary approaches are essential, particularly in patients from endemic regions who may harbor multiple co-infections. Strengthening clinical awareness, referral pathways, and appropriate screening for NTDs may help reduce diagnostic delays and improve patient outcomes in increasingly globalized healthcare settings. Full article

This case report describes the investigation of two cases of cutaneous vasculitis in sows following vaccination. The herd was porcine reproductive and respiratory syndrome virus (PRRSV)-stable, with routine PRRSV-1 and porcine circovirus type 2 (PCV2) sows’ vaccination. Two sows developed red-to-purple macules on the udder, flanks, and hind limbs, occurring two and three days after vaccination, respectively. Diagnostic investigations included biochemistry, complete blood count, PCR, immunohistochemistry (IHC), serology, histopathology, Gram staining, and immunofluorescence (IF) to assess the involvement of type III hypersensitivity. Clinical examination and herd evaluation revealed no significant abnormalities. Both sows showed biochemistry results within the reference intervals. One sow had lymphocytosis. All PCR PCV2, PCV3 and PRRSV-1/2 on serum and IHC PCV2 conducted on skin biopsies were negative, although both animals were seropositive for PCV2. Histopathology revealed necrotizing leukocytoclastic vasculitis, and Gram staining detected no bacteria. IF failed to identify immune complex or complement deposition. However, type III hypersensitivity could not be excluded, as immune complexes are transient and biopsies were collected about 48 h after lesion onset. Overall, the findings support a vaccine-related adverse reaction. Vaccine adverse effects should therefore be considered in the differential diagnosis of cutaneous vasculitis in swine. Full article