Clinical characteristics and progression of liver abscess caused by toxocara

Atypical Toxocara canis-Induced Hepatic Visceral Larva Migrans: Diagnostic Challenges and Literature Review

Toxocariasis, a zoonotic infection transmitted by Toxocara canis (from dogs) and Toxocara cati (from cats) larvae, poses rare but severe risks to humans. We present a case of hepatic visceral larva migrans (VLM) caused by Toxocara canis in a 21-year-old male with a history of close contact with a pet dog. Initial symptoms and imaging findings mimicked a pyogenic liver abscess. The initial laboratory investigations revealed neutrophilia and elevated levels of IgE. Despite broad-spectrum antibiotics, persistent fever prompted further investigation. Subsequent serological testing for Toxocara antibodies and histopathological analysis of liver tissue demonstrating eosinophil infiltrates and Charcot-Leyden crystals led to a confirmed diagnosis of a liver abscess caused by Toxocara canis. Serological testing for Toxocara antibodies and histopathological analysis of liver tissue confirmed a Toxocara canis-induced liver abscess. Albendazole treatment yielded significant clinical improvement. This case highlights the necessity of considering toxocariasis in liver abscess differentials, particularly in high-seroprevalence regions like Vietnam. Relying solely on serological tests may be insufficient, emphasizing the need for corroborative evidence, including invasive procedures like liver biopsy, for accurate hepatic toxocariasis diagnosis.

Real-time multiplex PCR for human echinococcosis and differential diagnosis

Molecular identification of rare human infectious pathogens appears to be one of the most relevant current methods for rapid diagnosis and management of patients. PCR techniques, in particular real-time quantitative PCR, are best suited for the detection of DNA from the pathogens, even at low concentrations. Echinococcosis infections are due to helminths of the Echinococcus genus, with closely related species involved in parasitic lesions affecting animals and, accidentally, humans. We developed a multiplex qPCR (MLX qPCR) assay allowing for the detection of four Echinococcus species involved in Europe in alveolar echinococcosis (AE) and cystic echinococcosis (CE) (Echinococcus multilocularis, E. granulosus sensu stricto, E. ortleppi, and E. canadensis), based on short mitochondrial targets. A collection of 81 fresh and formalin-fixed paraffin-embedded tissues (FFPE) of AE and CE lesions was assembled. The qPCR assays were performed in triplex for Echinococcus spp. detection, associated with a qPCR inhibitor control. A duplex qPCR was also designed to enable diagnosis of two other dead-end helminthiases (cysticercosis (Taenia solium), and toxocariasis (Toxocara cati and T. canis)). The sensitivity of the qPCR was assessed and ranged from 1 to 5 × 10^-4 ng/μL (seven PCR assays positive), corresponding to 37-42 cycles for quantifiable DNA. The specificity was 100% for all the targets. This multiplex qPCR, adapted to low amounts of DNA can be implemented in the laboratory for the rapid molecular diagnosis of Echinococcosis species.

High Dietary Organic Iron Supplementation Decreases Growth Performance and Induces Oxidative Stress in Broilers

Although Iron (Fe) is an essential nutrient that plays a vital role in respiratory processes, excessive Fe in the diet can affect the health of broilers. We investigated the effects of diet supplemented with high levels of iron chelates with lysine and glutamic acid (Fe−LG) on the growth performance, serum biochemical parameters, antioxidant status, and duodenal mRNA expression of Fe transporters in broilers. A total of 800 1-day-old male Arbor Acres broilers were assigned to 5 groups, with 8 replicates each. Broilers were fed a corn−soybean meal basal diet or basal diets supplemented with 40, 80, 400, or 800 mg Fe/kg as Fe−LG for 6 weeks. The body weight (BW) was increased in the 80 mg Fe/kg treatment group, but decreased in the 800 mg Fe/kg treatment group on day 21. During days 1−21, compared with the control group, the supplementation of the 80 mg Fe/kg increased the average daily gain (ADG) and average daily feed intake (ADFI); however, the supplementation of the 800 mg Fe/kg group decreased the ADG and increased the FCR in broilers (p < 0.05). The heart, liver, spleen, and kidney indices were reduced in the 800 mg Fe/kg treatment group (p < 0.05). The supplementation of the 800 mg Fe/kg group increased the serum aspartate aminotransferase activity and the levels of creatinine and urea nitrogen on day 42 (p < 0.05). The broilers had considerably low liver total superoxide dismutase activity and total antioxidant capacity in the 800 mg Fe/kg treatment group (p < 0.05). Serum and liver Fe concentrations were elevated in the 400 and 800 mg Fe/kg treatment groups, but were not affected in the 40 and 80 mg Fe/kg treatment groups. The duodenal Fe transporters divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) were downregulated in the Fe−LG treatment groups (p < 0.05). We conclude that a high dietary supplement of 800 mg Fe/kg in broilers leads to detrimental health effects, causing kidney function injury and liver oxidative stress.

Toxocara Awareness Among Medical Practitioners in Saudi Arabia

Human toxocariasis is a zoonotic infection with global and regional impacts. Worldwide it is underestimated and clinically overlooked. Medical practitioners are generally unaware of the extent of the resulting disease spectrum. The objective of the study was to assess knowledge and disease awareness among medical practitioners in Aseer, south-western Saudi Arabia. A questionnaire addressing knowledge about the parasite, its visceral larva migrans and the disease spectrum generated was used to interview participants. The study included 285 participants. In answer to the question what is toxocara, only 27%, answered correctly that it is a nematode, paediatricians being the majority. With regard to years of experience among participants, 56.8% of those who answered correctly had less than 5-year experience, as opposed to 35.4% for those with more than 10-year experience. The cumulative awareness about the disease manifestations and spectrum, i.e. those who knew, was less than 30% across specialties and years of experiences. Lack of awareness regarding Toxocara infection and the disease spectrum it can generate is evident. The consequence for such lack of knowledge within our practising medical community is simply unacceptable as it might translate into misdiagnosis and consequently misguided treatment.

Imaging of toxocariasis

Several imaging modalities have now been employed to visualize the manifestations of larval Toxocara infection in hepatic, neurologic, ocular, renal, and other anatomical sites. This report reviews the usefulness and value of these individual imaging methods in diagnosis and follow-up of the different cases causing eosinophilic (granulomatous) infiltrations the liver, lungs, brain, heart, and eyes. Imaging provides a means of assisting in diagnosis and management in this infection where diagnosis by biopsy is often unlikely to capture an actual larva for the purpose of making a definitive diagnosis on the basis of larval morphology or DNA detection.

Space Occupying Lesion in the Liver Caused by Hepatic Visceral Larva Migrans: A Case Report

Visceral larva migrans (VLM) is one of the clinical syndromes of human toxocariasis. We report a case of hepatic VLM presenting preprandial malaise and epigastric discomfort in a 58-year-old woman drinking raw roe deer blood. The imaging studies of the abdomen showed a 74-mm hepatic mass featuring hepatic VLM. Anti-Toxocara canis immunoglobulin G (IgG) was observed in enzyme-linked immunosorbent assay (ELISA) and western blot. Despite anthelmintic treatment, the patient complained of newly developed cough and skin rash with severe eosinophilia. Hepatic lesion increased in size. The patient underwent an open left lobectomy of the liver. After the surgery, the patient was free of symptoms such as preprandial malaise, epigastric discomfort, cough, and skin rash. Laboratory test showed a normal eosinophilic count at postoperative 1 month, 6 months, 1 year, and 4 years. The initial optical density value of 2.55 of anti-T. canis IgG in ELISA was found to be negative (0.684) at postoperative 21 months. Our case report highlights that a high degree of clinical suspicion for hepatic VLM should be considered in a patient with a history of ingestion of raw food in the past, presenting severe eosinophilia and a variety of symptoms which reflect high worm burdens. Symptom remission, eosinophilia remission, and complete radiological resolution of lesions can be complete with surgery.