Disseminated toxoplasmosis in non-allografted patients with hematologic malignancies: report of two cases and literature review

Cerebral Infectious Opportunistic Lesions in a Patient with Acute Myeloid Leukaemia: The Challenge of Diagnosis and Clinical Management

Central nervous system (CNS) lesions, especially invasive fungal diseases (IFDs), in immunocompromised patients pose a great challenge in diagnosis and treatment. We report the case of a 48-year-old man with acute myeloid leukaemia and probable pulmonary aspergillosis, who developed hyposthenia of the left upper limb, after achieving leukaemia remission and while on voriconazole. Magnetic resonance imaging (MRI) showed oedematous CNS lesions with a haemorrhagic component in the right hemisphere with lepto-meningitis. After 2 weeks of antibiotics and amphotericin-B, brain biopsy revealed chronic inflammation with abscess and necrosis, while cultures were negative. Clinical recovery was attained, he was discharged on isavuconazole and allogeneic transplant was postponed, introducing azacitidine as a maintenance therapy. After initial improvement, MRI worsened; brain biopsy was repeated, showing similar histology; and 16S metagenomics sequencing analysis was positive (Veilonella, Pseudomonas). Despite 1 month of meropenem, MRI did not improve. The computer tomography and PET scan excluded extra-cranial infectious-inflammatory sites, and auto-immune genesis (sarcoidosis, histiocytosis, CNS vasculitis) was deemed unlikely due to the histological findings and unilateral lesions. We hypothesised possible IFD with peri-lesion inflammation and methyl-prednisolone was successfully introduced. Steroid tapering is ongoing and isavuconazole discontinuation is planned with close follow-up. In conclusion, the management of CNS complications in immunocompromised patients needs an interdisciplinary approach.

Serological and molecular detection of Toxoplasma gondii in ß. thalassemia patients

Toxoplasma gondii is a worldwide opportunistic protozoan causing life-threatening infection in immunocompromised patients, while frequently asymptomatic in immunocompetent individuals. The current study aimed to detect T. gondii; serologically and molecularly in ß. thalassemia patients and evaluate the association of infection with some hematological parameters in these patients. Blood samples were collected from 100 ß. thalassemia patients. Serological diagnosis of T. gondii using ELISA for IgG and IgM antibodies was performed. Molecular diagnosis by Real-Time (RE) PCR was performed using specifically designed primers amplifying 389 bp fragments of Toxoplasma genome. 45 patients (45%) had anti-Toxoplasma IgG antibodies with no detectable IgM antibodies while both anti-Toxoplasma IgM and IgG antibodies were noticed in 10 patients (10%). IgM only antibodies were discovered in two cases (2%). The total seropositivity rate among patients was 57%. RE PCR analysis revealed Toxoplasma DNA in 20% out of 100 patients. PCR and serological examination showed slight agreement. A statistically significant relation was observed between the results of IgG and IgM ELISA and PCR for the detection of T. gondii infection among patients with ß. thalassemia. None of the studied risk factors (age, gender, contact with cats, consumption of undercooked meat) or hematological parameters (ESR, anemia degree, ferritin level, type of blood transfusion, spleen status) showed statistically significant association with Toxoplasma infection. It can be concluded that patients with thalassemia have a high risk of infection with T. gondii. RE PCR should be used as a diagnostic method in association with serology especially in immunocompromised patients to increase sensitivity.

Seroprevalence of Toxoplasma gondii infection in women with a gynecological tumor living in eastern China

The association between Toxoplasma gondii (T. gondii) infection and malignancy has attracted increased attention in recent years, but little is known of T. gondii infection among women diagnosed with a gynecological tumor (GT) in China. We conducted a case-control study involving 460 women diagnosed with a GT and 460 age-matched healthy controls (HCs) to estimate the infection process of T. gondii and understand the risk factors of T. gondii infection in patients with a GT. Levels of anti-T. gondii IgG and IgM were measured by enzyme-linked immunoassays every 12 months. After a median follow-up time of 4.3 years (range 4 to 5 years), 55/460 (11.96%) patients with a GT and 15/460 (3.26%) HCs were seroprevalence for T. gondii antibodies, respectively (P = 0.001). IgG antibodies against T. gondii were found in 54 GT patients (11.74%) and 15 HCs (3.26%), respectively (P = 0.001). The seroprevalence of T. gondii IgM antibodies was similar in patients with a GT and with HCs (2.83% vs 1.3%, P = 0.105). Multivariate stepwise logistic regression analysis revealed contact with cats (OR, 6.67; 95% CI [2.89-10.75]; P = 0.001), exposure to soil (OR, 2.16; 95% CI [1.14-4.10]; P = 0.019), being a farm-worker (OR, 4.17; 95% CI [1.20-11.49]; P = 0.006) and history of chemotherapy (OR, 3.16; 95% CI [1.56-6.45]; P = 0.001) to be independent risk factors for T. gondii infection. Women with an ovarian cancer or endometrial cancer had higher T. gondii seroprevalence than that of HCs. Moreover, T. gondii infection in patients with a GT mostly acquired within two years of diagnosis, but the infection in healthy controls had no obvious time characteristics. Here, we demonstrated that T. gondii infection is significantly higher in patients with a GT (especially in women with an ovarian tumor) compared to HCs. Thus, infection with this parasite should be avoided in patients with a GT, and the causal relationship between T. gondii and GTs should be studied in detail.

Clinical characteristics and incidence of toxoplasmosis after autologous hematopoietic stem cell transplantation: A retrospective study and literature review

BACKGROUND

Toxoplasmosis is a rare but life-threatening infection occurring in immunocompromised hosts, including allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. However, thus far, the clinical features and incidence of toxoplasmosis in autologous HSCT (auto-HSCT) recipients remain unknown. This retrospective survey aimed to analyze 152 patients who received auto-HSCT between 1998 and 2017.

METHODS

Serological tests for Toxoplasma gondii-specific IgG were performed on 109 (71.7%) recipients, and 12 pre-HSCT recipients (11%) were Toxoplasma seropositive. Among the 12 recipients, three who did not receive trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis developed cerebral, pulmonary or disseminated toxoplasmosis due to reactivation after auto-HSCT and died despite treatment.

RESULTS

The incidences of toxoplasmosis were 2% and 25% among 152 auto-HSCT recipients (five recipients received auto-HSCT two times) and 12 pre-HSCT Toxoplasma seropositive recipients, respectively. Further, we conducted a literature review and identified 21 cases of toxoplasmosis following auto-HSCT. In these previous cases, the mortality rate was high, especially for pulmonary and disseminated toxoplasmosis. Our findings suggest that, similar to toxoplasmosis after allo-HSCT, toxoplasmosis after auto-HSCT is a fatal complication.

CONCLUSIONS

Serial screening of T. gondii-specific IgG before HSCT could contribute to the detection of Toxoplasma reactivation and allow for prompt diagnosis and treatment. The present study is the first to reveal the incidence of toxoplasmosis after auto-HSCT among seropositive patients in Japan.

Invasion with Toxoplasma gondii can promote pneumocystis pneumonia in individuals with HIV/AIDS

Pulmonary pathology is common in HIV-infected individuals, but the possible role of the parasitic protist Toxoplasma gondii (Nicolle et Manceaux, 1908) is not completely known. The present account reports result of a retrospective cohort study. Medical cards of 907 HIV-positive people, which included 120 deceased patients, were analysed. During a three-year follow-up, the pulmonary pathology was diagnosed in 306 patients (33.7 ± 1.6%): pneumocystis pneumonia in 124 (13.7 ± 1.1%), primary pulmonary tuberculosis in 113 (12.5 ± 1.1%), bacterial pneumonia in 58 (6.4 ± 0.8%) toxoplasmosis pneumonia in two (0.2 ± 0.2%), and others. All patients were divided into two cohorts: 531 individuals seropositive for T. gondii and 376 seronegative ones. It has been found out that general lung pathology is more common in patients with seropositivity to T. gondii than in seronegative ones (43.3 ± 2.2% vs. 20.1 ± 2.0%, p < 0.001). The diagnosis of pneumocystis pneumonia was made ten times more often in the cohort of seropositive patients than in the cohort of seronegative ones (21.9 ± 1.8% vs. 2.1 ± 0.7%, respectively, p < 0.001) and in deceased patients of these cohorts it was 5.5 times more (45.1 ± 5.9% vs. 8.2 ± 3.9, respectively, p < 0.001). In patients with fatal outcome and seropositivity to T. gondii, the incidences of pneumocystis pneumonia increased by 23.2% (p < 0.001) and bacterial pneumonia by 12.4% (p < 0.05), whereas in seronegative individuals only pulmonary tuberculosis increased by 13.1% (p < 0.05) сompared with corresponding whole cohorts. Pearson's contingency coefficient showed the mean strength association between infection with T. gondii and incidence of pneumocystis pneumonia both in whole cohort (C = 0.272) and in patients with fatal outcomes (C = 0.368). In сonclusion, significantly increasing rate of pneumocystis pneumonia in patients with HIV/AIDS and T. gondii infection can be caused by certain synergism between T. gondii and Pneumocystis jirovecii and in some cases overdiagnosis pneumocystis pneumonia due to undiagnosed toxoplasmosis pneumonia.

Neurotoxoplasmosis in a Patient with Chronic Lymphocytic Leukemia

Teaching Point: Neurotoxoplasmosis should be part of the differential diagnosis for single or multiple cerebral lesions in hematologic patients.

Serology for Toxoplasma in Immunocompromised Patients: Still Useful?

Toxoplasmosis represents one of the most common comorbidity factors in solid organ or hematopoietic stem cell transplant recipients as well as in other immunocompromised patients. In the past decades, availability and performance of molecular tools for the diagnosis or the exclusion of toxoplasmosis in these patients have greatly improved. However, if accurately used, serology remains a complementary and essential diagnostic tool for physicians and medical parasitologists for the prevention and management of toxoplasmosis in immunocompromised patients as well. It is required for determination of the immunological status of patients against Toxoplasma. It also helps diagnose and monitor complex cases of opportunistic Toxoplasma infection in immunocompromised patients. New perspectives are available to further enhance their yield and ease of use.

Increased Risk of Toxoplasma gondii Infection in Patients with Colorectal Cancer in Eastern China: Seroprevalence, Risk Factors, and a Case-Control Study

The aim of this study was to explore the epidemiology of Toxoplasma gondii infection in patients with colorectal cancer (CRC) in eastern China. Therefore, 287 primary CRC patients and 287 age-matched healthy control subjects were recruited to estimate the seroprevalence of T. gondii and identify the risk factors of infection. Enzyme-linked immunoassays were used to test for anti-T. gondii immunoglobulin G (IgG) and IgM antibodies. Forty-six (16%) samples were positive for anti-T. gondii IgG antibodies in patients with CRC, compared with 26 (9.1%) in the healthy controls, a significant difference (P = 0.007). By contrast, eight (2.8%) patients tested positive for T. gondii IgM antibodies, compared with three (1.1%) in the controls, a difference that was not significant (P = 0.13). Multivariable backward stepwise logistic regression analysis revealed that a rural residence (OR 2.83; 95% CI 1.15–7.01; P = 0.024) and treatment with chemotherapy (OR 2.16; 95% CI 1.02–4.57; P = 0.045) were risk factors for T. gondii infection in patients with CRC. Thus, T. gondii infection is serious in patients with CRC, and a rural residence and treatment with chemotherapy are independent risk factors for infection by this parasite. Therefore, medical professionals should be aware of this pathogen in patients with CRC, and the causes of T. gondii infection in these patients need to be explored further.

Toxoplasma gondii infection in children with lymphoma in Eastern China: seroprevalence, risk factors and case-control studies

Epidemiological data for Toxoplasma gondii regarding malignancy have gained increasing attention; however, the information about T. gondii infection among children with malignant lymphoma (ML) in China is unclear. Therefore, 314 children with lymphoma and 314 healthy children, age- and gender-matched, were recruited to estimate the seroprevalence of T. gondii in the participants and identify the risk factors of infection. Blood samples from all participants were collected and examined for T. gondii IgG and IgM antibodies using ELISA. The results showed that the overall seroprevalence of T. gondii antibodies (including IgG and/or IgM) in ML patients and healthy controls was 19.8% and 9.9%, respectively. Contact with the cats, consumption of oysters and history of chemotherapy were estimated to be the risk factors for T. gondii infection in children with lymphoma by multivariable logistic regression analysis, whereas in healthy children, contact with cats and consumption of oysters were the risk factors. Moreover, among various histological types of lymphoma, individuals with NK/T-cell lymphoma, B-small lymphocytic lymphoma, marginal zone B-lymphoma and Hodgkin's lymphoma had a higher seroprevalence than healthy controls (P < 0.05). These findings indicated the high prevalence of T. gondii infection in children with lymphoma, and hence, efforts should be performed to evaluate the effect of the infection further in lymphoma patients.

High frequency of infection of lung cancer patients with the parasite Toxoplasma gondii

Background

Toxoplasma gondii is an intracellular protozoan parasite that can cause a wide range of clinical conditions, including miscarriage and pneumonia. The global prevalence is 30% in humans, but varies by locality (e.g. in the UK it is typically 10%). The association between lung cancer and T. gondii infection was investigated by direct detection in lung tissue samples.

Methods

Lung tissue samples were taken from patients undergoing lung resection surgery (n=72) for suspected lung cancer (infection prevalence 100% (95% CI: 93.9–100%)). All 72 participants were confirmed as having lung cancer following subsequent diagnostic tests. In addition, bronchial biopsy samples were collected from non-lung cancer healthy control subjects (n=10). Samples were tested for T. gondii using PCR amplification of T. gondii specific gene markers and T. gondii specific immunohistochemistry.

Results

All 72 lung cancer patients were infected with T. gondii (prevalence 100% (95% CI: 93.9–100%)). Of which, 95.8% (n=69) of patients showed evidence of active parasite stages. Infection prevalence in the controls (10%) was significantly lower (p<0.0001).

Conclusions

Clinicians treating lung cancer patients should be aware of the potential presence of the parasite, the potential for induction of symptomatic complications and interference with treatment success.

Toxoplasma gondii infection was found to be present in all lung tissue samples taken from 72 cancer patients (including active parasite stages in 96% of samples)http://bit.ly/2DhPPRN

A case of pulmonary toxoplasmosis resembling multiple lung metastases of nasal lymphoma in a cat receiving chemotherapy

An 11-year-old cat presented with nasal discharge and lacrimation and was diagnosed with nasal lymphoma. Although the cat showed favorable progression after undergoing chemotherapy, CT imaging demonstrated enlarged pulmonary nodules caused by Toxoplasma gondii. Following the cessation of chemotherapy, the cat was prescribed clindamycin hydrochloride for toxoplasmosis treatment; however, the cat developed kidney lymphoma and died. No T. gondii organisms were observed in the whole body necropsy specimens. It is known that immunocompromised human patients, including those who undergo chemotherapy, are considered at risk for toxoplasmosis. However, the risk of developing toxoplasmosis in cats undergoing chemotherapy is currently unknown. Findings from this case report suggest that cats with chemotherapy-resistant pulmonary masses might have a T. gondii infection rather than metastatic disease.

Treatment of Toxoplasmosis: Historical Perspective, Animal Models, and Current Clinical Practice

Primary Toxoplasma gondii infection is usually subclinical, but cervical lymphadenopathy or ocular disease can be present in some patients. Active infection is characterized by tachyzoites, while tissue cysts characterize latent disease. Infection in the fetus and in immunocompromised patients can cause devastating disease. The combination of pyrimethamine and sulfadiazine (pyr-sulf), targeting the active stage of the infection, is the current gold standard for treating toxoplasmosis, but failure rates remain significant. Although other regimens are available, including pyrimethamine in combination with clindamycin, atovaquone, clarithromycin, or azithromycin or monotherapy with trimethoprim-sulfamethoxazole (TMP-SMX) or atovaquone, none have been found to be superior to pyr-sulf, and no regimen is active against the latent stage of the infection. Furthermore, the efficacy of these regimens against ocular disease remains uncertain. In multiple studies, systematic screening for Toxoplasma infection during gestation, followed by treatment with spiramycin for acute maternal infections and with pyr-sulf for those with established fetal infection, has been shown to be effective at preventing vertical transmission and minimizing the severity of congenital toxoplasmosis (CT). Despite significant progress in treating human disease, there is a strong impetus to develop novel therapeutics for both the acute and latent forms of the infection. Here we present an overview of toxoplasmosis treatment in humans and in animal models. Additional research is needed to identify novel drugs by use of innovative high-throughput screening technologies and to improve experimental models to reflect human disease. Such advances will pave the way for lead candidates to be tested in thoroughly designed clinical trials in defined patient populations.

Seroprevalence and Molecular Evaluation of Toxoplasmosis in Patients Undergoing Chemotherapy for Malignancies in the Bushehr Province, Southwest Iran

Background

Toxoplasmosis is a life-threatening infection in organ transplant recipients, people receiving corticosteroid or radiation therapy, people with malignancies, and AIDS patients.

Objectives

The current study aimed to determine the prevalence of toxoplasmosis in patients receiving chemotherapy for malignancies in the Bushehr province of southwest Iran.

Methods

Blood samples were taken from 86 patients who were continuously referred to the chemotherapy center in Bushehr province and evaluated by ELISA to determine anti-Toxoplasma IgG and IgM antibodies. Moreover, a blood buffy coat of each sample was assessed by polymerase chain reaction (PCR), targeting a 529 bp gene of T. gondii. PCR products of the positive samples were sequenced to determine the genotype of the parasite.

Results

Anti-Toxoplasma IgG antibodies were detected in the sera of 21 (24.4%) cases. All of the patients were negative for anti-Toxoplasma IgM antibodies. No statistically significant correlation was found between seropositivity to Toxoplasma and duration of chemotherapy or having contact with cats. PCR detected a 529 bp band of T. gondii in the buffy coats of two out of 86 (2.3%) cases. The sequence analysis demonstrated that both cases were 95% identical to type III (VEG strain) of T. gondii.

Conclusions

Findings of this study demonstrated the presence of type III T. gondii in the buffy coats of patients undergoing chemotherapy. Given that toxoplasmosis is a life-threatening infection in immunocompromised patients, these patients should be screened for toxoplasmosis before and during chemotherapy to prevent acute toxoplasmosis.

Toxoplasma Encephalitis in Atypical Hosts at an Academic Cancer Center

Toxoplasma encephalitis is a well recognized complication of acquired immune deficiency syndrome, solid organ transplantation, and allogeneic hematopoietic stem cell transplantation (HSCT). However, patients with hematologic malignancies not treated with allogeneic HSCT may also develop this condition, which requires high clinical suspicion and consideration for prophylactic therapy.

Toxoplasmic Encephalitis with Untreated Hairy Cell Leukemia Variant

Toxoplasmic encephalitis is a rare infectious complication in patients with hematological malignancy except for allogeneic hematopoietic stem cell transplantation (HSCT). We herein report a case of possible toxoplasmic encephalitis with untreated hairy cell leukemia variant. Magnetic resonance imaging showed multiple nodules with surrounding edema in the entire cerebrum. A polymerase chain reaction analysis for Toxoplasma gondii was negative. Her signs and symptoms fully recovered by empirical therapy with sulfadiazine and pyrimethamine. Toxoplasmic encephalitis may occur in patients who undergo non-allogeneic HSCT for hematological malignancies, even in those who have not been treated.

Toxoplasmosis complicating lung cancer: a case report

Toxoplasmosis complicating lung cancer has been described only rarely. Here, we report a case of acute Toxoplasma gondii infection in a patient with squamous lung cancer. A 64-year-old woman was admitted to our hospital with a history of cough of 6 months' duration and chest pain of 1 week's duration. Further examination revealed multiple swollen lymph nodes, palpable on the top of the right collarbone and without tenderness. The chest X-ray, bronchoscopy, and computed tomography scan confirmed squamous carcinoma of the right lung. The Wright-stained bronchoalveolar-lavage fluid cytology diagnosis was positive for T. gondii and tachyzoites were detected. All of them were of free type (ectocytic), without intracellular parasites. Serological examination revealed that the anti-T. gondii immunoglobulin (Ig) M and IgG antibodies were positive. Unfortunately the patient did not continue treatment and was lost to follow-up. Toxoplasmosis is a life-threatening opportunistic infection in patients with lung cancer. Prompt recognition of T. gondii infection among cancer patients with subsequent targeted treatment of toxoplasmosis could help alleviate symptoms and improve survival.

Microbiological food safety and a low-microbial diet to protect vulnerable people

Low-microbial diets are advised by many institutions for people with neutropenia resulting from treatment with immunosuppressive drugs or medical conditions that increase their susceptibility to foodborne disease. In this article, the main microbiological hazards associated with foods are outlined, and a low-microbial diet in which higher-risk foods are replaced by lower-risk foods is described.