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1.  Atypical Strain of Toxoplasma gondii Causing Fatal Reactivation after Hematopoietic Stem Cell Transplantion in a Patient with an Underlying Immunological Deficiency 
Journal of Clinical Microbiology  2013;51(8):2686-2690.
In immunocompromized patients, including hematopoietic stem cell transplant (HSCT) recipients, life-threatening toxoplasmosis may result from reactivation of previous infection. We report a case of severe disseminated toxoplasmosis that developed early after allogeneic HSCT for T-cell lymphoblastic leukemia/lymphoma in a 15-year-old Toxoplasma gondii-seropositive boy with Nijmegen breakage syndrome, a rare genetic DNA repair disorder associated with immunodeficiency. The donor was the patient's HLA-identical brother. Prophylaxis with cotrimoxazole was discontinued a day before the HSCT procedure. Signs of lung infection appeared as early as day 14 post-HSCT. The presence of tachyzoite-like structures on Giemsa-stained bronchoalveolar lavage (BAL) fluid smears suggested toxoplasmosis. Real-time PCR targeted at the T. gondii AF146527 gene revealed extremely high parasite burdens in both blood and BAL fluid. Although immediate introduction of specific treatment resulted in a marked reduction of the parasite load and transient clinical improvement, the patient deteriorated and died of multiple organ failure on day 39 post-HSCT. Direct genotyping of T. gondii DNA from blood and BAL fluid with the PCR-restriction fragment length polymorphism method revealed type II alleles with SAG1, SAG2, and GRA6 markers but alleles of both type I and type II with GRA7. Additional analysis with 15 microsatellite markers showed that the T. gondii DNA was atypical and genetically divergent from that of the clonal type I, II, and III strains. This is the first report of increased clinical severity of toxoplasmosis associated with an atypical strain in the setting of immunosuppression, which emphasizes the need to diagnose and monitor toxoplasmosis by quantitative molecular methods in cases of reactivation risk.
PMCID: PMC3719651  PMID: 23761151
2.  Value of PCR for evaluating occurrence of parasitemia in immunocompromised patients with cerebral and extracerebral toxoplasmosis. 
Journal of Clinical Microbiology  1994;32(11):2813-2819.
PCR was used to evaluate the occurrence of Toxoplasma gondii parasitemia by detection of the B1 gene in blood samples in two groups of immunosuppressed patients (148 subjects) suspected of having cerebral or extracerebral infection, respectively. Group I consisted of 52 patients with AIDS with suspected cerebral toxoplasmosis. The diagnosis was clinically proven in 15 cases. Parasitemia was detected by PCR in only two of these patients (13.3%), both showing evidence of disseminated infection. Group II consisted of 96 immunocompromised patients, either with AIDS or receiving iatrogenic immunosuppressive therapy. Of these patients, 65 (34 with AIDS and 31 others) showed abnormalities only in chest radiography and were first screened for the presence of Toxoplasma DNA in bronchoalveolar lavage fluid. Blood was then analyzed when the parasite was detected in the bronchoalveolar lavage fluid. The remaining 31 subjects (22 with AIDS and 9 others) were suspected of having extracerebral, pulmonary, or disseminated toxoplasmosis, and blood was studied directly in these cases. Among the nine patients with clinically diagnosed extracerebral infection in group II, the parasite was detected by PCR in the blood of five patients (55.5%), all having pulmonary toxoplasmosis. If all patients with clinical manifestations of extracerebral toxoplasmosis (from both groups) who had not received antitoxoplasma therapy when the samples were collected are considered, PCR detected parasitemia in seven of the nine cases (77.8%). The present study indicates that examination of blood by PCR may be valuable in cases of extracerebral toxoplasmosis because of the disseminated nature of the disease. Since most cases of cerebral toxoplasmosis result from the local reactivation of latent brain cysts, detection of parasitemia by PCR is useful only in cases associated with severe cerebral infection or dissemination of this disease.
PMCID: PMC264163  PMID: 7852576
3.  Prenatal Treatment for Serious Neurological Sequelae of Congenital Toxoplasmosis: An Observational Prospective Cohort Study 
PLoS Medicine  2010;7(10):e1000351.
An observational study by Ruth Gilbert and colleagues finds that prenatal treatment of congenital toxoplasmosis could substantially reduce the proportion of infected fetuses that develop serious neurological sequelae.
The effectiveness of prenatal treatment to prevent serious neurological sequelae (SNSD) of congenital toxoplasmosis is not known.
Methods and Findings
Congenital toxoplasmosis was prospectively identified by universal prenatal or neonatal screening in 14 European centres and children were followed for a median of 4 years. We evaluated determinants of postnatal death or SNSD defined by one or more of functional neurological abnormalities, severe bilateral visual impairment, or pregnancy termination for confirmed congenital toxoplasmosis. Two-thirds of the cohort received prenatal treatment (189/293; 65%). 23/293 (8%) fetuses developed SNSD of which nine were pregnancy terminations. Prenatal treatment reduced the risk of SNSD. The odds ratio for prenatal treatment, adjusted for gestational age at maternal seroconversion, was 0.24 (95% Bayesian credible intervals 0.07–0.71). This effect was robust to most sensitivity analyses. The number of infected fetuses needed to be treated to prevent one case of SNSD was three (95% Bayesian credible intervals 2–15) after maternal seroconversion at 10 weeks, and 18 (9–75) at 30 weeks of gestation. Pyrimethamine-sulphonamide treatment did not reduce SNSD compared with spiramycin alone (adjusted odds ratio 0.78, 0.21–2.95). The proportion of live-born infants with intracranial lesions detected postnatally who developed SNSD was 31.0% (17.0%–38.1%).
The finding that prenatal treatment reduced the risk of SNSD in infected fetuses should be interpreted with caution because of the low number of SNSD cases and uncertainty about the timing of maternal seroconversion. As these are observational data, policy decisions about screening require further evidence from a randomized trial of prenatal screening and from cost-effectiveness analyses that take into account the incidence and prevalence of maternal infection.
Please see later in the article for the Editors' Summary
Editors' Summary
Toxoplasmosis is a very common parasitic infection. People usually become infected with Toxoplasma gondii, the parasite that causes toxoplasmosis, by eating raw or undercooked meat that contains the parasite, but it can also be contracted by drinking unfiltered water or by handling cat litter. Most people with toxoplasmosis never know they have the disease. However, if a pregnant woman becomes infected with T. gondii, she can transmit the parasite to her unborn baby (fetus). Overall, about a quarter of women who catch toxoplasmosis during pregnancy transmit the parasite to their fetus. If transmission occurs early during pregnancy, the resultant “congenital toxoplasmosis” increases the risk of miscarriage and the risk of the baby being born with brain damage, epilepsy, deafness, blindness, or developmental problems (“serious neurological sequelae”). In the worst cases, babies may be born dead or die soon after birth. Congenital toxoplasmosis caught during the final third of pregnancy may not initially cause any health problems but eyesight problems often develop later in life.
Why Was This Study Done?
Clinicians can find out if a woman has been infected with T. gondii during pregnancy by looking for parasite-specific antibodies (proteins made by the immune system that fight infections) in her blood. If the pattern of antibodies suggests a recent infection, the woman can be given spiramycin or pyrimethamine-sulfonamide, antibiotics that are thought to reduce the risk of transmission to the fetus and the severity of toxoplasmosis in infected fetuses. In some countries where toxoplasmosis is particularly common (for example, France), pregnant women are routinely screened for toxoplasmosis and treated with antibiotics if there are signs of recent infection. But is prenatal treatment an effective way to prevent the serious neurological sequelae or postnatal death (SNSD) associated with congenital toxoplasmosis? In this observational study, the researchers examine this question by studying a group of children identified as having congenital toxoplasmosis by prenatal or neonatal screening in six European countries. An observational study measures outcomes in a group of patients without trying to influence those outcomes by providing a specific treatment.
What Did the Researchers Do and Find?
The researchers followed 293 children in whom congenital toxoplasmosis had been identified by prenatal screening (in France, Austria, and Italy) or by neonatal screening (in Denmark, Sweden, and Poland) for an average 4 years. Two-thirds of the children received prenatal treatment for toxoplasmosis and 23 fetuses (8% of the fetuses) developed SNSD; nine of these cases of SNSD were terminated during pregnancy. By comparing the number of cases of SNSD among children who received prenatal treatment with the number among children who did not receive prenatal treatment, the researchers estimate that prenatal treatment reduced the risk of SNSD by three-quarters. They also estimate that to prevent one case of SNSD after maternal infection at 10 weeks of pregnancy, it would be necessary to treat three fetuses with confirmed infection. To prevent one case of SNSD after maternal infection at 30 weeks of pregnancy, 18 fetuses would need to be treated. Finally, the researchers report that the effectiveness of pyrimethamine-sulfonamide and spiramycin (which is less toxic) was similar, and that a third of live-born infants with brain damage that was detected after birth subsequently developed SNSD.
What Do These Findings Mean?
These findings suggest that prenatal treatment of congenital toxoplasmosis could substantially reduce the proportion of infected fetuses that develop SNDS and would be particularly effective in fetuses whose mothers acquired T. gondii during the first third of pregnancy. These findings should be interpreted with caution, however, because of the small number of affected fetuses in the study and because of uncertainty about the timing of maternal infection. Furthermore, these findings only relate to the relatively benign strain of T. gondii that predominates in Europe and North America; further studies are needed to test whether prenatal treatment is effective against the more virulent strains of the parasite that occur in South America. Finally, because this study is an observational study, its findings might reflect differences between the study participants other than whether or not they received prenatal treatment. These findings need to be confirmed in randomized controlled trials of prenatal screening, therefore, before any policy decisions are made about routine prenatal screening and treatment for congenital toxoplasmosis.
Additional Information
Please access these Web sites via the online version of this summary at
The US Centers for Disease Control and Prevention provides detailed information about all aspects of toxoplasmosis, including toxoplasmosis in pregnant women (in English and Spanish)
The UK National Health Services Choices website has information for patients about toxoplasmosis and about the risks of toxoplasmosis during pregnancy
KidsHealth, a resource maintained by the Nemours Foundation (a not-for-profit organization for children's health), provides information for parents about toxoplasmosis (in English and Spanish)
Tommy's, a nonprofit organization that funds research on the health of babies, also has information on toxoplasmosis
MedlinePlus provides links to other information on toxoplasmosis (in English and Spanish)
EUROTOXO contains reports generated by a European consensus development project
Uptodate provides information about toxoplasmosis and pregnancy
PMCID: PMC2953528  PMID: 20967235
4.  Diagnosis of acute pulmonary toxoplasmosis by visualization of invasive and intracellular tachyzoites in Giemsa-stained smears of bronchoalveolar lavage fluid. 
Journal of Clinical Microbiology  1991;29(11):2626-2627.
Two patients with AIDS presented with pulmonary toxoplasmosis. Diagnosis was achieved by the visualization, in Giemsa-stained smears of bronchoalveolar lavage fluid, of tachyzoites of Toxoplasma gondii that were extracellular and in the process of invading or within pneumocytes. The intracellular localization of tachyzoites facilitated diagnosis by obviating potential confusion of extracellular tachyzoites with cellular debris or platelets.
PMCID: PMC270389  PMID: 1774274
5.  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.
PMCID: PMC4309790  PMID: 25653562
lung cancer; Toxoplasma gondii; bronchoalveolar-lavage fluid; tachyzoite
6.  Comparison of four methods for rapid detection of Pneumocystis carinii in respiratory specimens. 
Journal of Clinical Microbiology  1990;28(11):2432-2436.
Four stains for the detection of Pneumocystis carinii in respiratory specimens were compared for sensitivity, specificity, preparation time, and ease of interpretation. One hundred specimens were collected. Of these, 50 were induced sputum specimens and 50 were bronchoalveolar lavage fluid. All specimens were stained with Diff-Quik (DQ) (a modified Giemsa stain), a quick silver stain, and direct and indirect immunofluorescence stains. A positive specimen was defined as any smear positive by two or more of the methods. Fifty-eight percent of specimens were positive. Seventy-four percent of the sputum specimens and 42% of the bronchoalveolar lavages were positive. The sensitivities for detection of P. carinii in sputum were 92% with silver stain, 97% with direct immunofluorescence assay (DFA), 97% with indirect immunofluorescence assay (IFA), and 92% with DQ. The sensitivities for detection in bronchoalveolar lavage were 86% with silver stain, 90% with DFA, 86% with IFA, and 81% with DQ. Preparation times varied from 90 min for the silver stain and IFA to 3 min for DQ. Costs of the tests varied from $1.50 per slide for DQ to $10.00 per slide for the silver stain and DFA. Reading times varied from 10 to 30 min for the silver stain and DQ to less than 5 min for the immunofluorescence assays. We conclude that all of these tests are viable options for the clinical laboratory, and the choice will be influenced by factors such as clinical volume, ability to batch specimens, and expertise of technological support. A reasonable option may be to use the quick and inexpensive DQ as a screening test and to confirm negative smears with a more sensitive assay.
PMCID: PMC268201  PMID: 1701444
7.  Value of bronchoalveolar lavage in the management of severe acute pneumonia and interstitial pneumonitis in the immunocompromised child. 
Thorax  1987;42(10):759-765.
The diagnostic value of 73 bronchoalveolar lavages was assessed in 67 immunocompromised children (aged 3 months to 16 years) with pulmonary infiltrates. Thirty one children had primary and 19 secondary immune deficiency, 14 acquired immunodeficiency syndrome (AIDS), and three AIDS related complex. Bronchoalveolar lavage was performed during fibreoptic bronchoscopy, under local anaesthesia in all but two. One or more infective agents was found in eight of 11 patients with severe acute pneumonia and in 26 of 62 patients with interstitial pneumonitis. In interstitial pneumonitis, the most frequently encountered agents were Pneumocystis carinii (12), cytomegalovirus (8), and Aspergillus fumigatus (3). The yield was related to the severity of interstitial pneumonitis. The mean cellular count and cytological profile in lavage returns from patients with varying infective agents or underlying pathological conditions showed no significant difference, except in those children with AIDS and AIDS related complex who had appreciable lymphocytosis (mean percentage of lymphocytes 28 (SD 17]. In children with AIDS and chronic interstitial pneumonitis lymphocytosis without pneumocystis infection was observed in eight of nine bronchoalveolar lavage returns and was suggestive of pulmonary lymphoid hyperplasia. Finally, bronchoalveolar lavage produced a specific diagnosis from the microbiological or cytological findings in 44 instances (60%). Transient exacerbation of tachypnoea was observed in the most severely ill children but there was no case of respiratory decompensation attributable to the bronchoscopy. Bronchoalveolar lavage is a safe and rapid examination for the investigation of pulmonary infiltrates in immunocompromised children. It should be performed as a first line investigation and should reduce the use of open lung biopsy techniques.
PMCID: PMC460948  PMID: 2827334
8.  Pulmonary alveolar proteinosis: diagnosis using routinely processed smears of bronchoalveolar lavage fluid. 
Journal of Clinical Pathology  1997;50(12):981-984.
AIMS: For the diagnosis of pulmonary alveolar proteinosis from bronchoalveolar lavage specimens it is normally necessary to make an ultrastructural examination. However, this is thought to be impractical for bronchoalveolar lavage specimens that have been routinely fixed in ethanol. In the present study, bronchoalveolar lavage cytology smears on slide glasses were examined directly ultrastructurally to make a diagnosis of pulmonary alveolar proteinosis. METHODS: Bronchoalveolar lavage smears from three pulmonary alveolar proteinosis patients were stained with Papanicolaou and periodic acid-Schiff (PAS) for identification of amorphous globular structures. Subsequently, they were refixed with glutaraldehyde and osmium tetroxide, and embedded in epoxy resin. Ultrathin sections were cut and examined ultrastructurally. RESULTS: Papanicolaou stained specimens from pulmonary alveolar proteinosis patients contained scattered amorphous or granular globules, 20-50 microns in diameter, which were PAS positive. Ultrastructural examination of the globules revealed multilamellated structures, characteristic of pulmonary alveolar proteinosis, in all cases. CONCLUSIONS: In general, it is thought that the morphological diagnosis of pulmonary alveolar proteinosis from bronchoalveolar lavage specimens requires both cytological and ultrastructural examination. However, the amorphous globules evident on cytology smears proved to contain multilamellated structures so that they can themselves be used as diagnostic evidence.
PMCID: PMC500376  PMID: 9516877
9.  Prevalence of toxoplasma myocarditis in patients with the acquired immunodeficiency syndrome. 
British Heart Journal  1993;70(4):376-381.
OBJECTIVE--To evaluate the prevalence of cardiac toxoplasmosis in a series of 182 necropsies performed between 1987 and 1991 on patients infected with the human immunodeficiency virus (HIV), to correlate this prevalence with the ante mortem diagnosis of cardiac involvement, and to assess the role of such cardiac lesions in the immediate cause of death. PATIENTS AND METHODS--Complete necropsies of 182 HIV-infected patients (48 women, 134 men) were performed consecutively between 1987 and 1991. Risk factors, identified in 174 cases, included drug abuse (111/182), homosexuality (51/182), and blood transfusions (12/182). 16 samples were systematically obtained from each heart for histological study. If trophozoites or lymphocytic myocarditis were seen, immunohistochemical investigations were carried out with polyclonal antibodies for Toxoplasma gondii. An ultrastructural study was performed in four patients with toxoplasma myocarditis. Myocardial lesions were defined by the Dallas classification. Clinical data (and information on electrocardiograms and echocardiograms) were obtained from medical records. RESULTS--Cardiac toxoplasmosis was diagnosed at necropsy in 21 (12%) patients. Cardiac lesions were associated with toxoplasmic encephalitis in 18 patients and were solitary in three patients. Acute diffuse myocarditis was present in 6/21, rare foci of myocarditis were seen in 8/21, and intramyocytic toxoplasmic cysts without any inflammatory reaction or necrosis were seen in 4/21. Anti-toxoplasma immunolabelling showed cardiac toxoplasmosis in three patients with lymphocytic myocarditis. Particles with the ultrastructural characteristics of Toxoplasma gondii trophozoites were seen in four cases. Six patients had presented with cardiac symptoms, confirmed by electrocardiographic and echocardiographic abnormalities during their disease course, and their cardiac lesions were directly responsible for the death. CONCLUSION--Cardiac toxoplasmosis was common in this necropsy series of HIV-infected patients. Cardiac toxoplasmosis had been suspected clinically in four patients. Myocardial lesions were generally asymptomatic and were not discovered until necropsy. Solitary cardiac involvement was not uncommon reflecting parasite reactivation at a myocardial site. The incidence of cardiac toxoplasmosis in this group of immunodepressed subjects from an area with a high prevalence of this parasitic disease justifies regular follow up of such patients by electrocardiography and echocardiography as well as immediate administration of anti-toxoplasma treatment should sudden heart failure occur.
PMCID: PMC1025336  PMID: 8217449
10.  Smear positive extra pulmonary tuberculosis disease at University of Gondar Hospital, Northwest Ethiopia 
BMC Research Notes  2013;6:21.
While pulmonary tuberculosis is the most common presentation, extra pulmonary tuberculosis is also an important clinical problem. However, no adequate information had been made available on the prevalence of smear positive extra pulmonary tuberculosis in Gondar. The aim of this study was to assess the prevalence and possible risk factors of smear positive extra pulmonary tuberculosis among suspected patients at University of Gondar Hospital.
A cross-sectional study on extra pulmonary tuberculosis suspected patients was conducted at University of Gondar Hospital from January 2012 to April, 2012. Specimens of patients suspected of extra pulmonary tuberculosis were obtained from fine needle aspiration and body fluid samples collected by pathologist. Demographic characteristics and other variables were collected using a pretested semi-structured questionnaire. Smears were prepared from each sample and stained by Ziehel Neelson and Wright stain. The result of the study was analyzed with bivariate and multivariate logistic regression.
A total of 344 extra pulmonary tuberculosis suspected clients were included in the study and specimens were taken from lymph node aspirates and body fluids. The overall prevalence of smear positive extra pulmonary tuberculosis was 34 (9.9%). Of these cases of extra pulmonary tuberculosis, lymph node tuberculosis constituted the largest proportion (82.4%). Among the 34 extra pulmonary tuberculosis patients, over half of them (52.9%) were positive for human immunodeficiency virus. The largest proportion of tuberculosis and human immunodeficiency virus cases occurred among persons with in the age group of 31–40 years. Previous history of tuberculosis (OR = 4.77, 95% CI 1.86-12.24), contact to a known tuberculosis cases (OR = 6.67 95% CI 2.78-16.90), history of underlying diseases (OR = 2.79 95% CI 1.15-6.78) and income (OR = 12.9 95% CI 2.25-68.02) were significantly associated with extra pulmonary tuberculosis infection.
The prevalence of smear positive extra pulmonary tuberculosis infection in Gondar is high. Screening of lymph node and other body fluid specimens for extra pulmonary tuberculosis could help for treatment, control and prevention of the disease.
PMCID: PMC3558382  PMID: 23331864
Extra pulmonary tuberculosis; Acid fast bacilli; Northwest Ethiopia
11.  Toxoplasmosis presenting as a swelling in the axillary tail of the breast and a palpable axillary lymph node mimicking malignancy: a case report 
Lymphadenopathy is a common finding in toxoplasmosis. A breast mass due to toxoplasmosis is very rare, and only a few cases have been reported. We present a case of toxoplasmosis that presented as a swelling in the axillary tail of the breast with a palpable axillary lymph node which mimicked breast cancer.
Case presentation
A 45-year-old otherwise healthy Caucasian woman presented with a lump on the lateral aspect of her left breast. Her mother had breast cancer that was diagnosed at the age of 66 years. During an examination, we discovered that our patient had a discrete, firm lump in the axillary tail of her left breast and an enlarged, palpable lymph node in her left axilla. Her right breast and axilla were normal. The clinical diagnosis was malignancy in the left breast. Ultrasound and mammographic examinations of her breast suggested a pathological process but were not conclusive. She had targeted fine-needle aspiration cytology (FNAC) and core biopsy of the lesions. FNAC was indeterminate (C3) but suggested a possibility of toxoplasmosis. The core biopsy was not suggestive of malignancy but showed granulomatous inflammation. She had a wide local excision of the breast lump and an axillary lymph node biopsy. Histopathology and immunohistochemical studies excluded carcinoma or lymphoma but suggested the possibility of intramammary and axillary toxoplasmic lymphadenopathy. The results of Toxoplasma gondii IgM and IgG serology tests were positive, supporting a diagnosis of toxoplasmosis.
Toxoplasmosis rarely presents as a pseudotumor of the breast. FNAC and histology are valuable tools for a diagnosis of toxoplasmosis, and serology is an important adjunct for confirmation.
PMCID: PMC3163609  PMID: 21816047
12.  Toxoplasmosis of Spinal Cord in Acquired Immunodeficiency Syndrome Patient Presenting as Paraparesis: A Rare Entity 
Although brain has been the most common site for toxoplasma infection in acquired immunodeficiency syndrome patients, involvement of spinal cord by toxoplasma has been rarely found. Spinal cord toxoplasmosis can present as acute onset weakness in both lower limbs associated with sensory and bladder dysfunction. A presumptive diagnosis can be made in patients with CD4 count <100/mm3 based on a positive serum Toxoplasma gondii IgG antibodies, no recent prophylaxis against toxoplasmosis, intramedullary ring enhancing lesion in spinal cord supported by similar lesions in brain parenchyma. Institutions of antitoxoplasma treatment in such patients result in prompt clinical response and therefore avoiding the need of unnecessary invasive diagnostic tests. Here, we report a case of toxoplasmic myelitis in immunocompromised patient presenting as myelopathy who showed significant clinical improvement after starting antitoxoplasma treatment. Hence toxoplasmic myelitis should be considered in toxoplasma seropositive immunocompromised patients presenting as myelopathy and imaging studies showing ring enhancing intramedullary lesion.
PMCID: PMC4265833  PMID: 25538456
Acquired immunodeficiency syndrome; Immunocompromised; Paraparesis; Spinal toxoplasmosis
13.  Diagnostic significance of immunoglobulin M antibodies to Toxoplasma gondii detected after separation of immunoglobulin M from immunoglobulin G antibodies. 
Journal of Clinical Microbiology  1980;12(3):336-342.
Failure to demonstrate immunoglobulin M (IgM) antibodies by indirect immunofluorescence (IgM-IFA) in sera from some patients with acute acquired toxoplasmosis has recently been attributed to an inhibitory effect of high titers of IgG antibodies in these sera (Pyndiah et al. J. Clin. Microbiol. 9:170-174, 1979). To confirm these findings and define their importance for diagnosis, we used gel filtration to separate IgM from IgG antibodies in a series of sera that were negative in the IgM-IFA test. A total of 68 sera were from patients with acquired toxoplasmosis, 13 were from uninfected adults, 13 were from infants with congenital toxoplasmosis, and 7 were from uninfected neonates. Of the 68 sera from patients with acquired toxoplasmosis, IgM preparations (from the separated sera) were positive in the IgM-IFA test in 36 (53%). There was a significant (P = 0.00003) association between high titers of IgM-IFA antibodies in the IgM preparations (corrected for dilution of IgM antibodies by the gel filtration procedure) and recent acquisition of infection. IgM antibodies were also detected in 5 (38%) of the IgM preparations of 13 sera from congenitally infected infants but not in any of the IgM preparations of sera from uninfected neonates. IgG antibodies to Toxoplasma gondii were shown to interfere with demonstration of IgM antibodies in the IgM-IFA test. Treatment of sera with protein A resulted in greater dilution of IgM antibodies and less efficient separation of IgM from IgG antibodies than did separation of sera by gel filtration. Treatment of sera with protein A did not result in increased detection of IgM antibodies to T. gondii. Testing of IgM preparations (obtained by gel filtration) resulted in a significant increase in sensitivity of the IgM-IFA test for the diagnosis of recently acquired and congenital toxoplasmosis.
PMCID: PMC273587  PMID: 7012170
14.  Severe Acquired Toxoplasmosis in Immunocompetent Adult Patients in French Guiana 
Journal of Clinical Microbiology  2002;40(11):4037-4044.
The most common presentation of symptomatic postnatally acquired toxoplasmosis in immunocompetent patients is painless cervical adenopathy. Acute visceral manifestations are associated in rare cases. We report 16 cases of severe primary toxoplasmosis diagnosed in French Guiana during a 6.5-year period. All of the subjects were immunocompetent adults hospitalized with clinical presentations consisting of a marked, nonspecific infectious syndrome accompanied by an altered general status with at least one visceral localization, mainly pulmonary involvement (14 cases). Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology. Recovery was rapid following specific antitoxoplasmosis treatment. Thirteen of the 16 patients had consumed game in the 2 weeks before the onset of the symptoms, and in eight cases the game was considered to have been undercooked. Toxoplasma strains, which were virulent in mice, were isolated from three patients. Microsatellite analysis showed that all of these isolates exhibited an atypical multilocus genotype, with one allele found only for isolates of this region.
PMCID: PMC139686  PMID: 12409371
15.  Human microsporidial infections. 
Clinical Microbiology Reviews  1994;7(4):426-461.
Microsporidia are obligate intracellular spore-forming protozoal parasites belonging to the phylum Microspora. Their host range is extensive, including most invertebrates and all classes of vertebrates. More than 100 microsporidial genera and almost 1,000 species have now been identified. Five genera (Enterocytozoon spp., Encephalitozoon spp., Septata spp., Pleistophora sp., and Nosema spp.) and unclassified microsporidia (referred to by the collective term Microsporidium) have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. Among persons not infected with human immunodeficiency virus, ten cases of microsporidiosis have been documented. In human immunodeficiency virus-infected patients, on the other hand, over 400 cases of microsporidiosis have been identified, the majority attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves. Initial detection of microsporidia by light microscopic examination of tissue sections and of more readily obtainable specimens such as stool, duodenal aspirates, urine, sputum, nasal discharge, bronchoalveolar lavage fluid, and conjunctival smears is now becoming routine practice. Definitive species identification is made by using the specific fluorescein-tagged antibody (immunofluorescence) technique or electron microscopy. Treatment options are limited, but symptomatic improvement of Enterocytozoon bieneusi infection may be achieved with the anthelmintic-antiprotozoal drug albendazole. Preliminary observations suggest that Septata intestinalis and Encephalitozoon infections may be cured with albendazole. Progress is being made with respect to in vitro propagation of microsporidia, which is crucial for developing antimicrosporidial drugs. Furthermore, molecular techniques are being developed for diagnostic purposes, taxonomic classification, and analysis of phylogenetic relationships of microsporidia.
PMCID: PMC358336  PMID: 7834600
16.  PCR Assay Using Cerebrospinal Fluid for Diagnosis of Cerebral Toxoplasmosis in Brazilian AIDS patients 
Journal of Clinical Microbiology  2004;42(10):4765-4768.
Highly active antiretroviral therapy has decreased the incidence of opportunistic infections in the central nervous system in AIDS patients. However, neurological abnormalities still remain important causes of mortality and morbidity in developing countries. In Brazil, cerebral toxoplasmosis is the most common cerebral mass lesion in AIDS patients. For these reasons, early, inexpensive, and sensitive diagnostic tests must be evaluated. The aim of this study was to evaluate PCR, using cerebrospinal fluid (CSF) samples to detect Toxoplasma gondii DNA, and to determine if the association of PCR with immunological assays can contribute to a timely diagnosis. We studied two sample groups. First, we analyzed stored CSF samples from 29 newborns and from 39 adults with AIDS without a definitive diagnosis of toxoplasmosis. The goal of this step was to standardize the methodology with a simple and economical procedure to recover the T. gondii DNA. Next, we prospectively evaluated CSF samples from 12 AIDS patients with a first episode of cerebral toxoplasmosis and 18 AIDS patients with other neurological opportunistic diseases and without previous cerebral toxoplasmosis. In all PCR samples, an indirect immunofluorescent assay and an enzyme-linked immunosorbent assay were performed. Samples from all patients with cerebral toxoplasmosis presented positive PCR results (sensitivity, 100%), and a sample from one of the 18 AIDS patients with other neurological diseases also presented positive PCR results (specificity, 94.4%). These findings suggest the clinical utility of PCR in the diagnosis of cerebral toxoplasmosis in developing countries.
PMCID: PMC522299  PMID: 15472338
17.  Optimization and Evaluation of a PCR Assay for Detecting Toxoplasmic Encephalitis in Patients with AIDS 
Journal of Clinical Microbiology  2002;40(12):4499-4503.
Toxoplasma gondii is a common life-threatening opportunistic infection. We used experimental murine T. gondii infection to optimize the PCR for diagnostic use, define its sensitivity, and characterize the time course and tissue distribution of experimental toxoplasmosis. PCR conditions were adjusted until the assay reliably detected quantities of DNA derived from less than a single parasite. Forty-two mice were inoculated intraperitoneally with T. gondii tachyzoites and sacrificed from 6 to 72 h later. Examination of tissues with PCR and histology revealed progression of infection from blood to lung, heart, liver, and brain, with PCR consistently detecting parasites earlier than microscopy and with no false-positive results. We then evaluated the diagnostic value of this PCR assay in human patients. We studied cerebrospinal fluid and serum samples from 12 patients with AIDS and confirmed toxoplasmic encephalitis (defined as positive mouse inoculation and/or all of the Centers for Disease Control clinical diagnostic criteria), 12 human immunodeficiency virus-infected patients with suspected cerebral toxoplasmosis who had neither CDC diagnostic criteria nor positive mouse inoculation, 26 human immunodeficiency virus-infected patients with other opportunistic infections and no signs of cerebral toxoplasmosis, and 18 immunocompetent patients with neurocysticercosis. Eleven of the 12 patients with confirmed toxoplasmosis had positive PCR results in either blood or cerebrospinal fluid samples (6 of 9 blood samples and 8 of 12 cerebrospinal fluid samples). All samples from control patients were negative. This study demonstrates the high sensitivity, specificity, and clinical utility of PCR in the diagnosis of toxoplasmic encephalitis in a resource-poor setting.
PMCID: PMC154600  PMID: 12454142
18.  Evaluation of an indirect fluorescent-antibody stain for detection of Pneumocystis carinii in respiratory specimens. 
Journal of Clinical Microbiology  1990;28(5):975-979.
Two prospective studies were undertaken to evaluate a commercial indirect fluorescent-antibody (IFA) stain for the detection of Pneumocystis carinii in respiratory specimens from individuals at risk for or with the acquired immunodeficiency syndrome. The first study compared IFA with Diff-Quik (DQ; a rapid Giemsa-like stain) for detecting P. carinii in 95 induced sputa obtained from 77 asymptomatic patients who had survived one previous episode of P. carinii pneumonia and who were being treated prophylactically with aerosolized pentamidine. Only one induced sputum specimen was found to contain P. carinii; organisms were detected by both stains. The second study compared the performance of the IFA stain versus DQ, modified toluidine blue O, and Gomori methenamine silver stains for detecting P. carinii in symptomatic individuals at risk for or with acquired immunodeficiency syndrome. Of 182 specimens examined, P. carinii was detected in 105 by one or more stains; the DQ stain detected 73 (70%), the modified toluidine blue O stain detected 75 (71%), the Gomori methenamine silver stain detected 76 (72%), and the IFA stain detected 95 (90%). The IFA stain was more sensitive (P less than 0.01) than the other traditional stains for detecting P. carinii; however, a subsequent clinical evaluation revealed that a subset of IFA-positive-only specimens were from patients whose clinical symptoms resolved without specific anti-P. carinii therapy.
PMCID: PMC267849  PMID: 1693631
A new serologic test for antibodies to Toxoplasma is described, which is based upon inhibition of specific staining with fluorescent antibody. In performing the test, a mixture of the test serum and known fluorescein-labelled antiserum is added to a dried smear of toxoplasms for 1 hour at 37°C. The smear is then rinsed and examined with a fluorescence microscope. Reduction in the brightness of fluorescence, as compared to that of a negative control slide, indicates the presence of antibody in the test serum. A comparison of the results of this test with those of the methylene blue dye test showed a strong parallelism between the two sets of results. On the other hand, the complement-fixation test for toxoplasmosis did not yield nearly as many positives as the inhibition test. The specificity of the new test was studied by comparing it with dye test results and clinical histories in human patients, and by testing a group of animals immunized with a variety of non-Toxoplasma antigens. No evidence of cross-reactions was obtained in the latter series. Some advantages and disadvantages of the inhibition test are discussed.
PMCID: PMC2136715  PMID: 13428924
20.  Comparative study of tissue culture and mouse inoculation methods for demonstration of Toxoplasma gondii. 
Journal of Clinical Microbiology  1987;25(9):1597-1600.
Two methods for the isolation of Toxoplasma gondii were analyzed and compared. Bradyzoites or tachyzoites of three strains of T. gondii were injected into mice and introduced in parallel onto MRC5 fibroblasts cultured on cover slips. In the cultures, the parasites were more readily identified by an indirect immunofluorescence assay than by examination of unstained or Giemsa-stained cultures. With the RH strain, the tachyzoites replicated actively, and large foci of parasites were observed in 24 h. The bradyzoites or tachyzoites of the other strains could also be cultivated, but grew rather slowly; 2 days after inoculation, early stages of multiplication could be observed: from day +4, Toxoplasma clusters or foci were easily identified at a x100 magnification. The course of infection in mice was greatly dependent on the virulence of the strain and on the parasitic stage inoculated. In the chronically infected mice, evidence of Toxoplasma infection was only detected 45 days after inoculation through the demonstration of cysts in the brain or the presence of specific antibodies in the serum. The mean ratio of infected mice and positive cultures was compared in relation to the inoculum size. The tissue culture method was found to be at least as sensitive as mouse inoculation. Since Toxoplasma organisms may be isolated within a few days in tissue culture, it is proposed that this method should be used when early isolation of the parasite is crucial for the diagnosis of toxoplasmosis.
PMCID: PMC269290  PMID: 3308946
21.  Serology in ocular toxoplasmosis. 
The diagnostic value of toxoplasma serology in ocular disease was evaluated in the following groups of patients: (I) uveitis cases of various causes (n = 291); (II) consecutive posterior and panuveitis patients (n = 60); (III) patients with definite congenital and ocular toxoplasmosis (n = 8); (IV) cases of clinical ocular toxoplasmosis (n = 25); and control patients with uveitis of non-toxoplasma origin (n = 12). No relation was observed between the level of the dye test titres and the diagnosis of ocular toxoplasmosis (groups I and II). During the active stages of the disease no typical change of the titres occurred in several longitudinally studied patients with toxoplasmosis. In group III one case was discovered to be negative by the dye test despite active ocular disease; however, IgG antibodies against toxoplasma were detected by the ELISA technique. In group IV, which was investigated by the ELISA technique, 100% of the toxoplasmosis patients were positive for IgG versus 58% of the control patients. Circulating immune complexes containing IgG and toxoplasma antigen were detected in seven of 25 toxoplasmosis patients (28%) and in two of 12 control patients (16%). Our study shows that the definite diagnosis of ocular toxoplasmosis or its exclusion by serological means only is not yet feasible. The possible superiority of the ELISA test to the dye test warrants further investigation.
PMCID: PMC1040784  PMID: 3741830
22.  Diagnosis of Cerebral Toxoplasmosis in AIDS Patients in Brazil: Importance of Molecular and Immunological Methods Using Peripheral Blood Samples 
Journal of Clinical Microbiology  2005;43(10):5044-5047.
Cerebral toxoplasmosis is the most common cerebral focal lesion in AIDS and still accounts for high morbidity and mortality in Brazil. Its occurrence is more frequent in patients with low CD4+ T-cell counts. It is directly related to the prevalence of anti-Toxoplasma gondii antibodies in the population. Therefore, it is important to evaluate sensitive, less invasive, and rapid diagnostic tests. We evaluated the value of PCR using peripheral blood samples on the diagnosis of cerebral toxoplasmosis and whether its association with immunological assays can contribute to a timely diagnosis. We prospectively analyzed blood samples from 192 AIDS patients divided into two groups. The first group was composed of samples from 64 patients with cerebral toxoplasmosis diagnosed by clinical and radiological features. The second group was composed of samples from 128 patients with other opportunistic diseases. Blood collection from patients with cerebral toxoplasmosis was done before or on the third day of anti-toxoplasma therapy. PCR for T. gondii, indirect immunofluorescence, enzyme-linked immunosorbent assay, and an avidity test for toxoplasmosis were performed on all samples. The PCR sensitivity and specificity for diagnosis of cerebral toxoplasmosis in blood were 80% and 98%, respectively. Patients with cerebral toxoplasmosis (89%) presented higher titers of anti-T. gondii IgG antibodies than patients with other diseases (57%) (P < 0.001). These findings suggest the clinical value of the use of both PCR and high titers of anti-T. gondii IgG antibodies for the diagnosis of cerebral toxoplasmosis. This strategy may prevent more invasive approaches.
PMCID: PMC1248484  PMID: 16207959
23.  Tomographic findings of acute pulmonary toxoplasmosis in immunocompetent patients 
BMC Pulmonary Medicine  2014;14(1):185.
Toxoplasmosis is one of the most common human zoonosis, and is generally benign in most of the individuals. Pulmonary involvement is common in immunocompromised subjects, but very rare in immunocompetents and there are scarce reports of tomographic findings in the literature. The aim of the study is to describe three immunocompetent patients diagnosed with acute pulmonary toxoplasmosis and their respective thoracic tomographic findings. Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology.
Case presentation
From 2009 to 2013, three patients were diagnosed with acute respiratory failure secondary to acute toxoplasmosis. The patients were two female and one male, and were 38, 56 and 36 years old. Similarly they presented a two-week febrile illness and progressive dyspnea before admission. Laboratory tests demonstrated lymphocytosis, slight changes in liver enzymes and high inflammatory markers. Tomographic findings were bilateral smooth septal and peribronchovascular thickening (100%), ground-glass opacities (100%), atelectasis (33%), random nodules (33%), lymph node enlargement (33%) and pleural effusion (66%). All the patients improved their symptoms after treatment, and complete resolution of tomographic findings were found in the followup.
These cases provide a unique description of the presentation and evolution of pulmonary tomographic manifestations of toxoplasmosis in immunocompetent patients. Toxoplasma pneumonia manifests with fever, dyspnea and a non-productive cough that may result in respiratory failure. In animal models, changes were described as interstitial pneumonitis with focal infiltrates of neutrophils that can finally evolve into a pattern of diffuse alveolar damage with focal necrosis. The tomographic findings are characterized as ground glass opacities, smooth septal and marked peribronchovascular thickening; and may mimic pulmonary congestion, lymphangitis, atypical pneumonia and pneumocystosis. This is the largest series of CT findings of acute toxoplasmosis in immunocompetent hosts, and the diagnosis should be considered as patients that present with acute respiratory failure in the context of a subacute febrile illness with bilateral and diffuse interstitial infiltrates with marked peribronchovascular thickening. If promptly treated, pulmonary toxoplasmosis can result in complete clinical and radiological recovery in immunocompetent hosts.
PMCID: PMC4254211  PMID: 25420956
Pulmonary toxoplasmosis; Chest; Toxoplasmosis
24.  Pneumocystis carinii: A review of an important opportunistic pathogen in AIDS 
Since the first report of human infection with Pneumocystis carinii in 1942, cases of pneumonia due to this opportunistic pathogen have become increasingly common. Animal studies and clinical observations show that a significant depletion or dysfunction of T helper lymphocytes predisposes to clinical disease. Individuals with damaged T helper cells secondary to malignancies (eg, Hodgkin’s lymphoma), drugs (eg, cyclosporine, steroids), or certain infections (eg, human immunodeficiency virus) are at particular risk. Serological studies suggest that disease is most often secondary to the reactivation of an asymptomatic infection, usually acquired during childhood. Increasing shortness of breath, a nonproductive cough and hypoxia often preceded by several weeks of lethargy, fever and weight loss are the classical features of P carinii pneumonia in acquired immune deficiency syndrome. Bronchoalveolar lavage is usually the optimal diagnostic test. Immunofluorescent staining on liquified sputum induced by nebulized saline appears to be a promising and noninvasive test. Early empiric therapy with trimethoprim-sulphamethoxazole (trimethoprim 5 mg-sulphamethoxazole 25 mg/kg/day every 6 h) or intravenous pentamidine (4 mg/kg/day) for 21 days is usually effective, but infection is not eradicated, and clinical disease is likely to recur. Prophylaxis using aerosolized pentamidine reduces the risk of pulmonary disease but can predispose to extrapulmonary infection. Improved in vitro and in vivo models of human pneumocystis infection would significantly increase understanding of the molecular biology of the organism, the pathogenesis of disease, and the optimal therapeutic regimens.
PMCID: PMC3307398  PMID: 22451747
Immunosuppression; Pneumocystis carinii; Pneumonia
25.  Immunoglobulin G Avidity in Diagnosis of Toxoplasmic Lymphadenopathy and Ocular Toxoplasmosis 
Traditional serological techniques have some limitations in evaluating the duration of Toxoplasma gondii infection in pregnant women, patients with lymphadenopathy, and older children suspected of having congenital toxoplasmosis. In these three groups of patients, two variants of T. gondii immunoglobulin G (IgG) avidity tests were used: an EIA Kit (Labsystems) and a noncommercial enzyme-linked immunosorbent assay specially elaborated in the laboratory. The avidity of specific IgG in sera from 23 patients with a known recently acquired infection (mainly pregnant women) was low (less than 30%), whereas that in sera from 19 patients with toxoplasmic lymphadenopathy of 3 weeks to 6 months in duration (mean, 8.3 weeks) covered a large range (between 0.2 and 57.8%; mean, 25.7%); high avidity results were observed for 10 of 19 patients (52.6%). The large range of IgG avidity in patients with toxoplasmic lymphadenopathy suggests various durations of infection in these patients, with a tendency for a chronic phase of toxoplasmosis. According to the avidity marker, five patients with lymphadenopathy for less than 3 months did not have a recent Toxoplasma infection. In 6 of 19 patients with lymphadenopathy (31.6%), low IgG avidity values persisted until 5 months after the first serological examination. In all four patients with a documented chronic course of Toxoplasma infection (6 months to 8 years after the first positive serology), high IgG avidity values were observed. Among sera from 10 children and young immunocompetent adults suspected of having ocular reactivation of congenital toxoplasmosis, all had high IgG avidity values (over 40%), suggesting congenitally acquired ocular infection rather than noncongenital infection. In conclusion, the avidity of IgG is a valuable marker of recent toxoplasmosis in pregnant women, suggests the duration of invasion in patients with lymphadenopathy, and may be helpful for differentiation between reactivation of congenital infection and recently acquired ocular toxoplasmosis in immunocompetent patients. A low IgG avidity does not always identify a recent case of toxoplasmosis, but a high IgG avidity can exclude primary infections of less than 5 months’ duration.
PMCID: PMC95718  PMID: 10391853

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