Pyogenic abscesses and parasitic diseases

Immature Sword Bean (Canavalia gladiata) Pod Alleviates Allergic Rhinitis (A Double-Blind Trial) Through PI3K/Akt/mTOR Signaling

Background: Allergic rhinitis is an IgE-mediated condition of nasal congestion, runny nose, and sneezing which significantly impairs the quality of life. Current treatments, including antihistamines, often have long-term side effects, leading patients to seek safer alternatives. Objectives: Therefore, in this study, we aimed to evaluate the symptom relief efficacy of immature sword bean pod (SBP) extract, a natural material, in patients with allergic rhinitis, explore the mechanisms by which SBP regulates allergic immune responses, and evaluate its efficacy and safety as a functional ingredient in the management of allergic rhinitis. Methods: In a double-blind, placebo-controlled, randomized trial involving 64 participants with perennial allergic rhinitis, the subjects were assigned to receive either SBP or placebo orally for six weeks. Results: The SBP group exhibited significant improvements in nasal congestion (interaction p = 0.031), RQLQ (interaction p = 0.001), sleep (interaction p = 0.004), systemic reaction (interaction p = 0.002), daily life (interaction p = 0.047), and nasal symptoms (interaction p = 0.002). SBP treatment in EoL-1 and HMC-1 cells also led to a notable reduction in eosinophil cationic protein levels (p < 0.05), a key biomarker of allergic inflammation, by inhibiting PI3K/Akt/mTOR activation, resulting in decreased eosinophil activity. Conclusions: These findings suggest that the SBP extract is a promising natural treatment for allergic rhinitis, offering both efficacy and safety by improving key symptoms and reducing inflammatory responses.

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.

Parasite-Induced Th2 Polarization—An Unusual Cause of Paediatric Hepatic Abscess

Liver abscess (LA) is a serious infectious disease, but is relatively rare in the paediatric population, especially in developed countries. Mostly, hepatic abscesses are pyogenic, caused by Staphylococcus aureus, while in extremely rare cases can be caused by parasites, such as Ascaris lumbricoides. Antimicrobial therapy and percutaneous drainage are the treatments of choice, lowering the mortality caused by this infection. We report a case of a 3-year-old girl admitted to the hospital for abdominal pain and a low-grade fever, with abdominal ultrasonography revealing a hepatic lesion. Initial laboratory tests showed moderate anaemia, thrombocytosis, eosinophilia, high inflammatory markers, and normal liver function. A computed tomography scan revealed two liver abscesses located subdiaphragmatically, and a high immunoglobulin E (IgE) value (22,300 U/mL). After excluding other possible etiologies, the patient was tested for parasitic infections. IgE for Ascaris lumbricoides came slightly higher. In addition to empirical antibiotic treatment, the patient received albendazole and made an uneventful recovery, with the full remission of the abscesses and without the need for drainage. In certain cases, parasites such as Ascaris lumbricoides are capable of inducing a T helper 2 (Th2) dominated immune response, predisposing the host to eosinophilia, hyperIgE, and increased susceptibility to bacterial infections. Early diagnosis and treatment in these cases may lead to less invasive therapy options in order to obtain a full recovery. To the best of our knowledge, this is the only reported case in the literature of a paediatric patient with parasite-induced liver abscesses, with extremely high IgE values, minimal symptomatology, that made a fast, full recovery without the need of drainage.

Parasite-bacteria interrelationship

Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.

Pyogenic and Amebic Infections of the Liver

Pyogenic liver abscesses are classified by the bacteria that have caused the abscess because this guides treatment and can point to the underlying cause. The most common cause is biliary disease. The diagnosis is made by imaging. Treatment is a combination of antibiotics and percutaneous drainage. Amebic liver abscess is caused by extraintestinal spread of Entamoeba histolytica. E histolytica is spread by fecal-oral transmission and typically colonizes the gastrointestinal tract. It is diagnosed based on imaging and the mainstay of treatment is metronidazole. Only about 15% of cases require percutaneous drainage. The prognosis is good, with almost universal recovery.

Asymptomatic pyogenic liver abscesses secondary to Fusobacterium nucleatum and Streptococcus vestibularis in an immunocompetent patient

A 66-year-old male patient presented with symptoms and signs of L4/5 radiculopathy. He was found to be anaemic with elevated inflammatory markers and deranged hepatic enzymes. Imaging revealed lumbar canal stenosis and the presence of pyogenic liver abscesses from which Fusobacterium nucleatum and Streptococcus vestibularis were isolated. The hepatic abscesses were attributed to asymptomatic diverticular perforation. Multiple coexisting incidental infections were discovered, including oesophageal candidiasis, Helicobacter pylori, stool cultures positive for Strongyloides stercoralis, and sputum cultures positive for Enterobacter cloacae, Escherichia coli and Mycobacterium avium Extensive investigations for possible underlying immunosuppression were negative.

Revisiting the concept of hepatosplenic schistosomiasis and its challenges using traditional and new tools

Different aspects of hepatosplenic schistosomiasis are revisited here. Manson's schistosomiasis causes periportal fibrosis and portal hypertension in approximately 6% of infected subjects, usually with preservation of their hepatic function. The assessment of liver involvement is of major importance in determining the prognosis and risk of complications from schistosomiasis, such as upper digestive bleeding secondary to variceal rupture. For many years, the diagnosis of hepatosplenic schistosomiasis and liver fibrosis was made by abdominal palpation and the finding of liver and/or spleen enlargement. However, there is no consensus regarding the clinical parameters of the liver and spleen to be considered in this physical evaluation. For the last three decades, abdominal ultrasound (US) has become the best imaging technique to evaluate liver fibrosis caused by schistosomiasis mansoni. However, US is a subjective procedure and is therefore examiner-dependent. Magnetic resonance imaging (MRI) findings have provided valuable information in addition to ultrasound and clinical examination. The combination of a comprehensive history and physical examination, basic laboratory tests (a stool examination for Schistosoma mansoni eggs and a blood cell count), biomarkers for liver fibrosis/portal hypertension and imaging methods seem to offer the best approach for evaluating patients with this disease. In situations where research is involved or in patients with severe disease, MRI may be considered.

Clinical manifestations and risk factors of amebic liver abscess in Southeast Taiwan compared with other regions of Taiwan

Amebic liver abscess (ALA) had previously been endemic in Taiwan, particularly in the southern region, although its occurrence in the southeastern area was unknown. Thus, we conducted a retrospective study for southeastern Taiwan. We identified 14 patients who were diagnosed with ALA between July of 1995 and July of 2008. These patients were predominantly male and older in age. Most patients lived in rural areas (85.7%). Alcoholism (78.6%) and diabetes (35.7%) were risk factors for ALA. No human immunodeficiency virus (HIV) infections were detected. The most common clinical symptoms were fever (100%) and abdominal pain (100%). Short mean durations of symptoms, high bilirubin levels, and low albumin levels were also noted. Most patients (92.86%) had a single lesion, particularly in the right liver lobe (71.4%). Six patients also had secondary Klebsiella pneumoniae bacterial infections. Clinicians should be aware of the different risk factors in different regions when diagnosing amebic liver abscess in Taiwan.

An outbreak of acute Schistosoma mansoni Schistosomiasis in a nonendemic area of Brazil: a report on 50 cases, including 5 with severe clinical manifestations

BACKGROUND

Acute schistosomiasis is a systemic hypersensitivity reaction against the migrating schistosomula and eggs. In this report, we describe an atypical outbreak of the disease with severe cases. Transmission occurred in a nonendemic area of Brazil, which became a new focus of transmission due to the in-migration of infected workers.

METHODS

From December 2009 to March 2010, the 50 patients with acute schistosomiasis (group 1) bathed in a swimming pool supplied by a brook on a country estate in the outskirts of São João del Rei, Brazil. Thirty other subjects (group 2) living in the same area, who denied having contact with the swimming pool, volunteered to participate in the study. All participants were submitted to clinical, laboratory, and ultrasound examinations.

RESULTS

Five of 50 (10%) patients were admitted to the hospital: 1 with myeloradiculopathy, 1 with diffuse pulmonary micronodules, and 3 with diarrhea and dehydration. All 5 had hypereosinophilia and prolonged fever. Group 1 patients more frequently had cercarial dermatitis (P = .01), blood in the stool (P = .04), and intra-abdominal lymph nodes (P = .001). All group 1 patients were treated with praziquantel; 1 patient with myeloradiculopathy also received oral prednisone (60 mg/day) for 6 months with complete recovery.

CONCLUSIONS

This report describes the first time that patients from an outbreak of acute schistosomiasis have been compared to controls. Five subjects (10%) had severe manifestations of schistosomiasis. Diagnosis of the disease and its severity was delayed because physicians did not consider that an epidemic of schistosomiasis might emerge in a nonendemic area.

A 12-year-old Child with Trichinellosis, Pyomyositis and Secondary Osteomyelitis

Trichinellosis is a parasitic infestation affecting the skeletal muscles. Cases of trichinellosis in humans have been reported from most regions of the world. However, a review of literature revealed only two reported cases of human trichinellosis in India. Further, a diagnosis of superimposed pyomyositis in trichinellosis with secondary osteomyelitis has not been reported to our knowledge. This article reports this rare case presentation in a 12-year-old child. Timely intervention helped prevent long-term morbidity in our patient. In our case report, we also discuss in detail the pathogenesis of such a condition and discuss the role of imaging modalities and an early magnetic resonance imaging (MRI) to diagnose the condition and start an early treatment.

Coinfection of Schistosoma (Trematoda) with bacteria, protozoa and helminths

This review examines coinfection of selected species of Schistosoma with bacteria, protozoa and helminths and focuses on the effects of the coinfection on the hosts. The review is based mainly on tables that contain the salient information on the coinfecting organisms in vertebrate hosts. Further explanation and clarification of the tables are given in the text. A table is also provided that gives synoptic information on the 37 species in the 19 genera considered in this review. Coinfection studies with Schistosoma species and the other organisms were considered in six tables plus the accompanying text. Considerations of the Schistosoma interactions with another species of organism include studies on coinfection with Plasmodium, with protozoa other than Plasmodium; with Salmonella, with bacteria other than Salmonella; and with Fasciola, with helminths other than Fasciola. Numerous factors were found to influence the effects of coinfection on the vertebrate host, including organisms and hosts used in the studies, order and time interval between the first and the second infection, studies on natural versus experimental hosts, dosage of the infectious agents, strains and pedigrees of the parasites, age of hosts at time of exposure to the infectious agents and age of hosts at the time of necropsy. Overall, a prior infection with Schistosoma, particularly a patent infection, often has an effect on the subsequent infection by a protozoan, bacterium or other helminth. In relatively few cases, a prior infection with Schistosoma decreased the severity of the subsequent infection as with Helicobacter pylori, Fasciola hepatica, Echinostoma or Plasmodium, the latter only exhibiting this behaviour when coinfected with Schistosoma haematobium. More often, however, a prior infection with Schistosoma increased the severity of the second infection as with Leishmania, Toxoplasma gondii, Entamoeba histolytica, Staphylococcus aureus or Salmonella. In some of these coinfection studies, the increased severity of the subsequent infection was associated with a specific, prolonged form of the disease in humans, which has implications for patient treatment and recovery. Additional research is needed, particularly on Schistosoma coinfections which currently have a small body of research and are current problems in human populations. Examples of such Schistosoma interactions include the genera of Mycobacteria, Leishmania, Staphylococcus, Necator and Strongyloides. Hopefully, future studies will elucidate valuable new information on the interesting subject of coinfection of Schistosoma with other organisms.

Acute schistosomiasis mansoni: revisited and reconsidered

Acute schistosomiasis is a systemic hypersensitivity reaction against the migrating schistosomula and eggs. A variety of clinical manifestations appear during the migration of schistosomes in humans: cercarial dermatitis, fever, pneumonia, diarrhoea, hepatomegaly, splenomegaly, skin lesions, liver abscesses, brain tumours and myeloradiculopathy. Hypereosinophilia is common and aids diagnosis. The disease has been overlooked, misdiagnosed, underestimated and underreported in endemic areas, but risk groups are well known, including military recruits, some religious congregations, rural tourists and people practicing recreational water sports. Serology may help in diagnosis, but the finding of necrotic-exudative granulomata in a liver biopsy specimen is pathognomonic. Differentials include malaria, tuberculosis, typhoid fever, kala-azar, prolonged Salmonella bacteraemia, lymphoma, toxocariasis, liver abscesses and fever of undetermined origin. For symptomatic hospitalised patients, treatment with steroids and schistosomicides is recommended. Treatment is curative in those timely diagnosed.

Pyomositis: a report of three cases

Pyomyositis, a subacute bacterial infection of muscles, is uncommon in children. Three children with pyomyositis and multiple abscesses caused by Staphylococcus aureus are reported. The intercostal muscles were involved in one case, the paraspinal muscles in another and in the third there was associated septic arthritis.

Genital schistosomiasis mansoni: tubal tumor and parietal peritoneum involvement diagnosed during laparoscopy

Female genital schistosomiasis is not uncommon in endemic areas for schistosomiasis, but there are few reports in the Brazilian medical literature. Here, we describe the case of a 31-year-old woman with lower abdominal pain who was diagnosed as presenting a fallopian tube tumor caused by Manson's schistosomiasis. The diagnosis was delayed because her symptoms were considered nonspecific. Involvement of the parietal peritoneum of the ovarian fossa was observed during laparoscopy and confirmed by histological analysis. The left tube and the tumor were excised and schistosomiasis was treated with praziquantel. She presented a full recovery and options for future reproduction are under evaluation.

Simultaneous Klebsiella pneumoniae and amoebic liver abscess in an immunocompetent patient

Simultaneous Klebsiella pneumoniae and amoebic liver abscess is rarely reported in immunocompetent patients. A 47-year-old man was hospitalized with abdominal pain, fever, chills, and hypotension. Physical examination revealed right upper quadrant tenderness. Abdominal computed tomography showed an area of low attenuation with some liquefaction in the liver. Echo-guided aspiration revealed 30 mL of pus, which grew Klebsiella pneumoniae, and the same organism was isolated from the blood. Cytology examination of the pus showed scattered amoeba. The patient gradually improved over 1 month on treatment with cefmetazole and metronidazole, along with repeated drainage of the abscess. His amoebic indirect hemagglutination titer was 1:128, but no parasite ova or amoeba were found in the stool. He had no evidence of immunocompromise. Parasitic diseases may be a predisposing factor for bacterial infections, including pyogenic liver abscess. The possible coexistence of amoebae and bacteria in a liver abscess should not be discounted.

[Chronic fever associated with splenic abscess due to Staphylococcus epidermidis]

Occult abscesses are frequent causes of chronic fever. Splenic abscesses are rare entities that are usually associated with underlying conditions such as abdominal surgery, endocarditis or immunodepression. We report on the case of a patient with prolonged fever caused by a splenic abscess, whose main differential diagnosis was visceral leishmaniasis. However, this condition was probably related to abdominal trauma. The treatment consisted of antibiotics followed by splenectomy.

Schistosomiasis mansoni and severe gastrointestinal cytomegalovirus disease in a patient with acquired immunodeficiency syndrome

The behavior of the Schistosoma mansoni infection in patients with AIDS has not been explored. The case of a young woman with schistosomiasis mansoni, AIDS, and cytomegalovirus disease is reported. The authors suggest that the helminth was not a bystander in this case, or rather, by interfering with the host's immune response, it set the stage for the development and/or aggravation of the viral infection.

Manifestation of toxocariasis in children with neuroblastoma treated with autologous hematopoietic transplants

Toxocariasis was diagnosed in 3 out of 22 children (14%) treated in our center with high-dose chemotherapy and autologous hematopoietic stem cell transplantation (HSCT). The patients were coming from rural areas in the southeastern Poland and did not present any clinical symptoms of toxocariasis upon admission to the hospital. Although no neurological and ophthalmological abnormalities were noticed, the atypical form of toxacariasis was diagnosed based on elevated eosinophils counts, positive serological tests, and biochemical symptoms of liver damage. The authors conclude that toxocariasis should be taken into consideration in the differential diagnosis of eosinophilia in children undergoing high-dose chemotherapy and HSCT, especially if they are coming from rural areas.

Pyogenic liver abscess in patients with schistosomiasis mansoni

Schistosomiasis mansoni has been described as a predisposing factor for pyogenic liver abscess formation. Previous experimental studies have shown that acute schistosomiasis concurrent with Staphylococcus aureus bacteremia favors the colonization of the liver by the bacteria, and subsequent pyogenic liver abscess formation. In addition, clinical studies and case reports have demonstrated the association of schistosomiasis mansoni with pyogenic liver abscesses. We describe a Brazilian patient with chronic schistosomiasis mansoni who developed recurrent pyogenic liver abscesses due to Pseudomonas aeruginosa. The authors review the clinical, diagnostic and treatment aspects of patients with schistosomiasis and pyogenic liver abscess reported in the medical literature.

Alteration in the endogenous intestinal flora of swiss webster mice by experimental Angiostrongylus costaricensis infection

The association between worm infections and bacterial diseases has only recently been emphasized. This study examined the effect of experimental Angiostrongylus costaricensis infection on endogenous intestinal flora of Swiss Webster mice. Eight mice aging six weeks were selected for this experiment. Four were infected with A. costaricensis and the other four were used as controls. Twenty eight days after the worm infection, all mice in both groups were sacrificed and samples of the contents of the ileum and colon were obtained and cultured for aerobic and anaerobic bacteria. In the mice infected with A. costaricensis there was a significant increase in the number of bacteria of the endogenous intestinal flora, accompanied by a decrease in the number of Peptostreptococcus spp. This alteration in the intestinal flora of mice infected by the nematode may help to understand some bacterial infections described in humans.

[Toxocariasis in adults]

PURPOSE

Toxocariasis is a widespread zoonotic parasitosis that is frequent in France. It is due to the presence of larvae of roundworms belonging to the genus Toxocara in the human body. Clinical signs are often non-specific. The disease can be asymptomatic or can lead to death. Toxocariasis can be thought of because of clinical signs or presence of hypereosinophilia, but the diagnosis is made by specific serology. Since there is no consensus to date regarding treatment, prevention is of paramount importance.

CURRENT KNOWLEDGE AND KEYPOINTS

Recent studies point out the frequency of this parasitic disease that is often asymptomatic. The serological diagnosis remains the main tool for the diagnosis of toxocariasis.

FUTURE PROSPECTS AND PROJECTS

Further studies on toxocariasis should focus on the prevalence of this disease in French population regarding the probability of infection: living in the countryside, food habits, hygiene and presence of dogs in the neighborhood. Tools of the biological diagnosis (mainly serological techniques) should be improved, but, especially, studies should focus on the evaluation of specific treatment in order to give unquestionable guidelines on this point.

Dexamethasone treatment improves morphological and hematological parameters in chronic experimental schistosomiasis

Schistosomiasis, a chronic disease with considerable social impact, is an important health problem in many countries. To investigate the possible use of immunomodulators as coadjuvants in the treatment of chronic Schistosoma mansoni infection, we evaluated the effect of dexamethasone on histological, hematological, and biochemical parameters that reflect disease severity and morbidity. Animals treated from the first day or after 35 days of infection, were analyzed. In both groups, dexamethasone: (1) induced a decrease in the number of granulomas in hepatic tissue without affecting the alanine aminotransferase profile, (2) reduced splenomegaly and hepatomegaly associated with disease, and (3) improved hemoglobin concentration, hematocrit values and reduced the percentage of reticulocytes, preventing the development of anemia that occurs in the chronic phase of infection. These data suggest that treatment with dexamethasone results in a mild course of murine schistosomiasis and point to this drug as a promising agent to complement S. mansoni specific treatment.

Cytokine milieu of atopic dermatitis, as compared to psoriasis, skin prevents induction of innate immune response genes

Atopic dermatitis (AD) and psoriasis are the two most common chronic skin diseases. However patients with AD, but not psoriasis, suffer from frequent skin infections. To understand the molecular basis for this phenomenon, skin biopsies from AD and psoriasis patients were analyzed using GeneChip microarrays. The expression of innate immune response genes, human beta defensin (HBD)-2, IL-8, and inducible NO synthetase (iNOS) was found to be decreased in AD, as compared with psoriasis, skin (HBD-2, p = 0.00021; IL-8, p = 0.044; iNOS, p = 0.016). Decreased expression of the novel antimicrobial peptide, HBD-3, was demonstrated at the mRNA level by real-time PCR (p = 0.0002) and at the protein level by immunohistochemistry (p = 0.0005). By real-time PCR, our data confirmed that AD, as compared with psoriasis, is associated with elevated skin production of Th2 cytokines and low levels of proinflammatory cytokines such as TNF-alpha, IFN-gamma, and IL-1beta. Because HBD-2, IL-8, and iNOS are known to be inhibited by Th2 cytokines, we examined the effects of IL-4 and IL-13 on HBD-3 expression in keratinocyte culture in vitro. We found that IL-13 and IL-4 inhibited TNF-alpha- and IFN-gamma-induced HBD-3 production. These studies indicate that decreased expression of a constellation of antimicrobial genes occurs as the result of local up-regulation of Th2 cytokines and the lack of elevated amounts of TNF-alpha and IFN-gamma under inflammatory conditions in AD skin. These observations could explain the increased susceptibility of AD skin to microorganisms, and suggest a new fundamental rule that may explain the mechanism for frequent infection in other Th2 cytokine-mediated diseases.