Incidence and risk factors for toxoplasmic encephalitis in human immunodeficiency virus-infected patients before and during the highly active antiretroviral therapy era

Calcified cerebral toxoplasmosis associated with recurrent perilesional edema causing neurological manifestations in an HIV-infected individual: case report with a decade-long follow-up

Four cases of people living with HIV/AIDS (PLWHA) with calcified cerebral toxoplasmosis associated with perilesional edema causing a single episode of neurological manifestations have recently been reported. Here, we describe the first detailed description of perilesional edema associated with calcified cerebral toxoplasmosis causing three episodes of neurological manifestations in a PLWHA, including seizures in two of them. These recurrences occurred over approximately a decade. Throughout this period, the patient showed immunological and virological control of the HIV infection, while using antiretroviral therapy regularly. This case broadens the spectrum of an emerging presentation of calcified cerebral toxoplasmosis, mimicking a well-described finding of neurocysticercosis in immunocompetent hosts.

Transcriptomic and metabolomic analyses reveal the essential nature of Rab1B in Toxoplasma gondii

BACKGROUND

The protozoan parasite Toxoplasma gondii encodes a dozen Rab proteins, which are parts of the small GTPase superfamily and regulate intracellular membrane trafficking. Our previous study showed that depletion of Rab1B caused severe defects regarding parasite growth and morphological structure, yet early defects of endocytic trafficking and vesicle sorting to the rhoptry in T. gondii are not expected to have a strong effect. To understand this discrepancy, we performed an integrated analysis at the level of transcriptomics and metabolomics.

METHODS

In the study, tetracycline-inducible TATi/Ty-Rab1B parasite line treated with ATc at three different time points (0, 18 and 24 h) was used. We first observed the morphological changes caused by Rab1B depletion via transmission electron technology. Then, high-throughput transcriptome along with non-targeted metabolomics were performed to analyze the RNA expression and metabolite changes in the Rab1B-depleted parasite. The essential nature of Rab1B in the parasite was revealed by the integrated omics approach.

RESULTS

Transmission electron micrographs showed a strong disorganization of endo-membranes in the Rab1B-depleted parasites. Our deep analysis of transcriptome and metabolome identified 2181 and 2374 differentially expressed genes (DEGs) and 30 and 83 differentially expressed metabolites (DEMs) at 18 and 24 h of induction in the tetracycline-inducible parasite line, respectively. These DEGs included key genes associated with crucial organelles that contain the rhoptry, microneme, endoplasmic reticulum and Golgi apparatus. The analysis of qRT-PCR verified some of the key DEGs identified by RNA-Seq, supporting that the key vesicular regulator Rab1B was involved in biogenesis of multiple parasite organelles. Functional enrichment analyses revealed pathways related to central carbon metabolisms and lipid metabolisms, such as the TCA cycle, glycerophospholipid metabolism and fatty acid biosynthesis and elongation. Further correlation analysis of the major DEMs and DEGs supported the role of Rab1B in biogenesis of fatty acids (e.g. myrisoleic acid and oleic acid) (R > 0.95 and P < 0.05), which was consistent with the scavenging role in biotin via the endocytic process.

CONCLUSIONS

Rab1B played an important role in parasite growth and morphology, which was supported by the replication assay and transmission electron microscopy observation. Our multi-omics analyses provided detailed insights into the overall impact on the parasite upon depletion of the protein. These analyses reinforced the role of Rab1B in the endocytic process, which has an impact on fatty acid biogenesis and the TCA cycle. Taken together, these findings contribute to our understanding of a key vesicular regulator, Rab1B, on parasite metabolism and morphological formation in T. gondii.

Animal venoms: a novel source of anti-Toxoplasma gondii drug candidates

Toxoplasma gondii (T. gondii) is a nucleated intracellular parasitic protozoan with a broad host selectivity. It causes toxoplasmosis in immunocompromised or immunodeficient patients. The currently available treatments for toxoplasmosis have significant side effects as well as certain limitations, and the development of vaccines remains to be explored. Animal venoms are considered to be an important source of novel antimicrobial agents. Some peptides from animal venoms have amphipathic alpha-helix structures. They inhibit the growth of pathogens by targeting membranes to produce lethal pores and cause membrane rupture. Venom molecules generally possess immunomodulatory properties and play key roles in the suppression of pathogenic organisms. Here, we summarized literatures of the last 15 years on the interaction of animal venom peptides with T. gondii and attempt to explore the mechanisms of their interaction with parasites that involve membrane and organelle damage, immune response regulation and ion homeostasis. Finally, we analyzed some limitations of venom peptides for drug therapy and some insights into their development in future studies. It is hoped that more research will be stimulated to turn attention to the medical value of animal venoms in toxoplasmosis.

Toxoplasmosis Encephalitis: A Cross-Sectional Analysis at a U.S. Safety-Net Hospital in the Late cART Era

Despite decreasing incidence of toxoplasmosis encephalitis(TE) among people living with HIV(PLWH) in the late antiretroviral era, U.S. safety-net hospitals still see significant numbers of admissions for TE. Little is known about this population, their healthcare utilization and long-term outcomes. We conducted an 8-year retrospective review of PLWH with TE at a safety-net hospital. Demographics, clinical characteristics, treatments, readmissions, and outcomes were collected. We used chi-squared test to evaluate 6-month all-cause readmission and demographic/clinical characteristics. Of 38 patients identified, 79% and 40% had a new diagnosis of TE and HIV respectively. 59% had 6-month all-cause readmission. Social factors were associated with readmission (uninsured (p = 0.036), Spanish as primary language (p = 0.017), non-adherence (p = 0.030)) and not markers of clinical severity (ICU admission, steroid-use, concomitant infections, therapeutic adverse events). Despite high readmission rates, at follow-up, 60% had a complete response, 30% had a partial response. Improving TE outcomes requires focus on culturally competent, coordinated care.

Acquired Immunodeficiency Syndrome Presented as Atypical Ocular Toxoplasmosis

Background

The aim is to report an atypical presentation of ocular toxoplasmosis which led to the diagnosis of Acquired Immunodeficiency Syndrome (AIDS). Case Report. The 38-year-old woman was referred with metamorphopsia and reduced vision in the right eye over the past 3 weeks. Slit-lamp examination revealed granulomatous keratic precipitates (KPs), 2+ cells in the anterior chamber, and posterior synechiae. Fundus examination was remarkable for a white patch surrounding a scar, inferonasal to the optic disc with fibrous bands emanating from the lesion, and the retina around this region was detached with considerable extension towards the periphery, while no breaks could be appreciated. She mentioned anorexia and losing 10 kg in the past three months, and signs of anemia like paleness of face skin, bed nails, and bilateral angular cheilitis were observed on systemic evaluation. The results of the patient's complete blood count revealed anemia and leukopenia and CD4 lymphocytes: 79 cells/μL. Enzyme-linked immunosorbent assays (ELISA) for HIV antibodies came back positive which was later confirmed with the Western blot test. Brain magnetic resonance imaging (MRI) showed multiple ring-enhancing lesions in both cerebral cortices. The patient underwent antitoxoplasmosis and anti-HIV treatment and serous retinal detachment completely resolved.

Conclusion

This report highlights the fact that sometimes, the eyes are the site of the first presentation of a systemic life-threatening condition and emphasizes the role of ophthalmologists in such cases. In cases of atypical presentation, appropriate laboratory tests and CNS imaging should be requested. Systemic treatment with antitoxoplasmosis regimens and highly active antiretroviral therapy (HAART) is mandatory in AIDS patients with ocular toxoplasmosis.

Epidemiology, Pathophysiology, Diagnosis, and Management of Cerebral Toxoplasmosis

Toxoplasma gondii is known to infect a considerable number of mammalian and avian species and a substantial proportion of the world's human population. The parasite has an impressive ability to disseminate within the host's body and employs various tactics to overcome the highly regulatory blood-brain barrier and reside in the brain. In healthy individuals, T. gondii infection is largely tolerated without any obvious ill effects. However, primary infection in immunosuppressed patients can result in acute cerebral or systemic disease, and reactivation of latent tissue cysts can lead to a deadly outcome. It is imperative that treatment of life-threatening toxoplasmic encephalitis is timely and effective. Several therapeutic and prophylactic regimens have been used in clinical practice. Current approaches can control infection caused by the invasive and highly proliferative tachyzoites but cannot eliminate the dormant tissue cysts. Adverse events and other limitations are associated with the standard pyrimethamine-based therapy, and effective vaccines are unavailable. In this review, the epidemiology, economic impact, pathophysiology, diagnosis, and management of cerebral toxoplasmosis are discussed, and critical areas for future research are highlighted.

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.

Management of Advanced HIV Disease

Great progress has been made in caring for persons with human immunodeficiency virus. However, a significant proportion of individuals still present to care with advanced disease and a low CD4 count. Careful considerations for selection of antiretroviral therapy as well as close monitoring for opportunistic infections and immune reconstitution inflammatory syndrome are vitally important in providing care for such individuals.

HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Quality of life and handgrip strength of HIV patients diagnosed with neurotoxoplasmosis

Abstract HIV / AIDS epidemic continues to be a major public health problem, and when there is poor adherence to treatment, patients become susceptible to other infections such as toxoplasmosis. The aim of this study was to evaluate the handgrip strength and quality of life of HIV infected patients diagnosed with neurotoxoplasmosis. A cross-sectional study was conducted with 40 HIV-infected patients, with and without diagnosis of neuroxoplasmosis.Sociodemographic and clinical profile information was collected, and handgrip strength and quality of life were evaluated. Almost all patients of both groups used antiretroviral therapy. In the handgrip strength evaluation, no statistical difference was observed for the right and left hand between groups with and without neurotoxoplasmosis (p> 0.05). However, the classifica-1 Federal University of Pará. Gradution of inadequate handgrip strength in the neurotoxoplasmosis group was significantly higher.ate Program in Tropical Diseases. In the quality of life domain, it was observed that financial concern had lower scores in the Belém, PA. Brazil. group with neurotoxoplasmosis (p = 0.0379). It was observed that neurotoxoplasmosis showedno association with epidemiological, clinical, handgrip strength and quality of life variables.2 State University of Pará. Center However, patients with neurotoxoplasmosis showed a trend towards lower muscle strength.

Disseminated toxoplasmosis in a patient with advanced acquired immunodeficiency syndrome

Extracerebral toxoplasmosis, with pulmonary involvement and shock, is a rare form of toxoplasmosis in patients with advanced AIDS. It can mimic pneumocystosis, histoplasmosis, and disseminated tuberculosis, and should be considered in the differential diagnosis of causes of respiratory failure and fulminant disease in this group of individuals, especially in areas where the Toxoplasma gondii infection is highly prevalent and in those without proper use of antimicrobial prophylaxis. We report the case of a 46-year-old male patient who presented to the emergency department with uremia, requiring urgent dialysis. During the laboratorial investigation, the patient had confirmed HIV infection, with a low CD4+ peripheral T-cell count (74 cells/µL). During hospitalization, the patient presented drug-induced hepatitis due to trimethoprim/sulfamethoxazole in a prophylactic dose, requiring interruption of this medication. On the 55th day of hospitalization, the patient developed refractory shock and died. At the autopsy, disseminated toxoplasmosis with encephalitis and severe necrotizing pneumonia were diagnosed, with numerous tachyzoites in the areas of pulmonary necrosis.

Central nervous system infection with Toxoplasma gondii

Central nervous system infection by Toxoplasma gondii, or Toxoplasma encephalitis, is the most common cause of brain mass lesions in human immunodeficiency virus (HIV)-infected patients. It usually presents as one or more brain abscesses, but it can also cause a diffuse encephalitis or ventriculitis. Individuals who are Toxoplasma immunoglobulin G-seropositive, who have peripheral blood CD4+ T-cell concentrations below 200/μL, are not on antiretroviral therapy, and are not taking trimethoprim-sulfamethoxazole to prevent Pneumocystis pneumonia, are at particular risk for Toxoplasma encephalitis. Neuroimaging typically shows round, isodense or hyperdense lesions in the hemispheric gray-white junction, deep white matter, or basal ganglia that enhance with contrast in a ring, nodular, or homogeneous pattern. In appropriate patients, response to an empiric treatment trial can establish the diagnosis. Immune reconstitution inflammatory syndrome is uncommon in HIV-infected patients treated for Toxoplasma encephalitis and combination antiretroviral therapy is an integral part of toxoplasmosis treatment.

Successful Treatment of Pulmonary and Cerebral Toxoplasmosis Associated with Pneumocystis Pneumonia in an HIV Patient

In both the post and pre combination antiretroviral therapy (cART) era, Pneumocystis jirovecii and Toxoplasma gondii remain common opportunistic infectious agents. The common manifestations are pneumonia for P. jirovecii and brain abscess for T. gondii. Nevertheless, co-infection remains rare, and pulmonary toxoplasmosis is scarce, or may be underestimated because of its similarity with Pneumocystis jirovecii pneumonia. We reported an uncommon case of an AIDS patient (6 CD4 + T cells/mm³) with both pulmonary and cerebral toxoplasmosis associated with pneumocystis pneumonia. The patient presented with general weakness, fever and dyspnea. Pulmonary toxoplasmosis and pneumocystis were confirmed by microscopic examination and DNA detection in the bronchoalveolar lavage. Computed tomography imaging of the brain revealed a single characteristic cerebral toxoplasmosis lesion of the left capsular area. He was successful treated by trimethoprim/sulfamethoxaxole in conjunction with an early reintroduction of cART, and without IRIS development. During a 3-year follow-up, HIV viral load remained undetectable, and the patient did not relapse for toxoplasmosis or Pneumocystis pneumonia.

Downregulated IL-21 Response and T Follicular Helper Cell Exhaustion Correlate with Compromised CD8 T Cell Immunity during Chronic Toxoplasmosis

CD8 T cells are important for maintaining the chronicity of Toxoplasma gondii infection. In a T. gondii encephalitis susceptible model, we recently demonstrated that CD4 T cells play an essential helper role in the maintenance of the effector response and CD8 T cell dysfunctionality was linked to CD4 T cell exhaustion. However, CD4 T cells are constituted of different subsets with various functions and the population(s) providing help to the CD8 T cells has not yet been determined. In the present study, T follicular helper cells (Tfh), which are known to be essential for B cell maturation and are one of the main sources of IL-21, were significantly increased during chronic toxoplasmosis. However, at week 7 p.i., when CD8 T cells are exhausted, the Tfh population exhibited increased expression of several inhibitory receptors and levels of IL-21 in the serum were decreased. The importance of IL-21 in the maintenance of CD8 T cells function after T. gondii infection was further demonstrated in IL-21R KO mouse model. Interestingly, while CD8 T cells from both knockout (KO) and wild-type mice expressed similar levels of PD-1, animals with defective IL-21 signaling exhibited lower polyfunctionality than wild-type controls. This reduced polyfunctional ability observed in CD8 T cells from KO mice was associated with a significant increase in other inhibitory receptors like Tim-3, LAG-3, and 2B4. Furthermore, the animals exhibited greater signs of Toxoplasma reactivation manifested by the reduced number of cysts and increased expression of tachyzoite (replicative form of the parasite) specific genes (SAG1 and ENO2) in the brain. Also, IL-21R KO mice displayed a higher frequency of tachyzoite-infected monocytes in the blood and spleen. Our findings suggest the importance of Tfh and IL-21 during chronic toxoplasmosis and establish a critical role for this cytokine in regulating CD8 T cell dysfunction by preventing the co-expression of multiple inhibitory receptors during chronic parasitic infection.

Artemisinin and its derivatives in treating protozoan infections beyond malaria

Parasitic protozoan diseases continue to rank among the world's greatest global health problems, which are also common among poor populations. Currently available drugs for treatment present drawbacks, urging the need for more effective, safer, and cheaper drugs. Artemisinin (ART) and its derivatives are some of the most important classes of antimalarial agents originally derived from Artemisia annua L. However, besides the outstanding antimalarial and antischistosomal activities, ART and its derivatives also possess activities against other parasitic protozoa. In this paper we review the activities of ART and its derivatives against protozoan parasites in vitro and in vivo, including Leishmania spp., Trypanosoma spp., Toxoplasma gondii, Neospora caninum, Eimeria tenella, Acanthamoeba castellanii, Naegleria fowleri, Cryptosporidium parvum, Giardia lamblia, and Babesia spp. We conclude that ART and its derivatives may be good alternatives for treating other non-malarial protozoan infections in developing countries, although more studies are necessary before they can be applied clinically.

Latent Toxoplasma Infection and Higher Toxoplasma gondii Immunoglobulin G Levels Are Associated With Worse Neurocognitive Functioning in HIV-Infected Adults

BACKGROUND

 Human immunodeficiency virus (HIV)-associated neurocognitive disorders persist despite suppressive antiretroviral therapy (ART). Because latent Toxoplasma infection (LTI) may adversely impact brain function, we investigated its impact on neurocognitive impairment (NCI) in people living with HIV disease.

METHODS

 Two hundred sixty-three HIV-infected adults underwent comprehensive neurocognitive assessments and had anti-Toxoplasma gondii immunoglobulin G (anti-Toxo IgG) measured by qualitative and quantitative enzyme-linked immunosorbent assays.

RESULTS

 Participants were mostly middle-aged white men who were taking ART (70%). LTI was detected in 30 (11.4%) participants and was associated with a significantly greater prevalence of global NCI (LTI positive [LTI⁺] = 57% and LTI negative [LTI^-] = 34%) (odds ratio, 1.67; 95% confidence interval, 1.17-2.40; P = .017). Deficits were more prevalent in the LTI⁺ vs the LTI^- group in 6 of 7 cognitive domains with statistical significance reached for delayed recall (P < .01). The probability of NCI increased with higher CD4⁺ T-cell counts among LTI⁺ individuals but with lower CD4⁺ T-cell counts in LTI^- persons. A strong correlation (r = .93) between anti-Toxo IgG levels and global deficit score was found in a subgroup of 9 patients. Biomarkers indicative of central nervous system inflammation did not differ between LTI⁺ and LTI^- participants.

CONCLUSIONS

 In this cross-sectional analysis, LTI was associated with NCI, especially in those with higher CD4⁺ T-cell counts. Longitudinal studies to investigate the role of neuroinflammation and neuronal injury in LTI patients with NCI and trials of anti-Toxoplasma therapy should be pursued.

Cerebral toxoplasmosis in patients with acquired immune deficiency syndrome in the neurological emergency department of a tertiary hospital

INTRODUCTION

Cerebral toxoplasmosis is the most common cause of space occupying brain lesion in patients with HIV/AIDS in Brazil. In the post-HAART era, it is responsible for high rates of morbidity and mortality worldwide.

MATERIALS AND METHODS

This study consists of a case series of 56 patients diagnosed with cerebral toxoplasmosis whose clinical features, brain imaging and cerebrospinal fluid aspects were analyzed.

RESULTS

Cerebral toxoplasmosis led to the diagnosis of infection by the human immunodeficiency virus (HIV) in 27 (48.2%) of the patients, while 29 (51.2%) others already knew to be HIV seropositive. However, at the time of diagnosis of cerebral toxoplasmosis, only 9 (16.6%) reported being under antiretroviral therapy and 5 (8.9%) were receiving primary prophylaxis for toxoplasmosis. Headache, strength deficit and fever were the most frequent signs and symptoms throughout the study. Fifty-three patients showed changes consistent with toxoplasmosis in CT or MRI. Thirty-four (60.7%) CSF samples were positive in the indirect haemagglutination test and for the reaction of Toxoplasma gondii IgG ELISA, while 31 (55.4%) were positive in the direct haemagglutination test. Fifty (89.3%) patients underwent first-line treatment for toxoplasmosis.

CONCLUSION

Cerebral toxoplasmosis is still a very relevant neurological disease in individuals with AIDS admitted to neurology emergency departments. Early diagnosis and initiation of empiric treatment and antiretroviral therapy are important for good prognosis.

Performance Testing of PCR Assay in Blood Samples for the Diagnosis of Toxoplasmic Encephalitis in AIDS Patients from the French Departments of America and Genetic Diversity of Toxoplasma gondii: A Prospective and Multicentric Study

BACKGROUND

Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana.

METHODOLOGY/PRINCIPAL FINDINGS

Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay.

CONCLUSION/SIGNIFICANCE

Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00803621.

Incidence of Opportunistic Infections and the Impact of Antiretroviral Therapy Among HIV-Infected Adults in Low- and Middle-Income Countries: A Systematic Review and Meta-analysis

BACKGROUND

To understand regional burdens and inform delivery of health services, we conducted a systematic review and meta-analysis to evaluate the effect of antiretroviral therapy (ART) on incidence of key opportunistic infections (OIs) in human immunodeficiency virus (HIV)-infected adults in low- and middle-income countries (LMICs).

METHODS

Eligible studies describing the cumulative incidence of OIs and proportion on ART from 1990 to November 2013 were identified using multiple databases. Summary incident risks for the ART-naive period, and during and after the first year of ART, were calculated using random-effects meta-analyses. Summary estimates from ART subgroups were compared using meta-regression. The number of OI cases and associated costs averted if ART was initiated at a CD4 count ≥200 cells/µL were estimated using Joint United Nations Programme on HIV/AIDS (UNAIDS) country estimates and global average OI treatment cost per case.

RESULTS

We identified 7965 citations, and included 126 studies describing 491 608 HIV-infected persons. In ART-naive patients, summary risk was highest (>5%) for oral candidiasis, tuberculosis, herpes zoster, and bacterial pneumonia. The reduction in incidence was greatest for all OIs during the first 12 months of ART (range, 57%-91%) except for tuberculosis, and was largest for oral candidiasis, Pneumocystis pneumonia, and toxoplasmosis. Earlier ART was estimated to have averted 857 828 cases in 2013 (95% confidence interval [CI], 828 032-874 853), with cost savings of $46.7 million (95% CI, $43.8-$49.4 million).

CONCLUSIONS

There was a major reduction in risk for most OIs with ART use in LMICs, with the greatest effect seen in the first year of treatment. ART has resulted in substantial cost savings from OIs averted.

Cerebro-meningeal infections in HIV-infected patients: a study of 116 cases in Libreville, Gabon

BACKGROUND

Cerebro-meningeal pathology is common in human immunodeficiency virus (HIV) infection and the aetiology is often difficult to ascertain with certainty.

OBJECTIVE

To describe the major suspected and identified causes of meningeal or encephalitic syndromes in HIV infection in Libreville, Gabon.

METHODS

A descriptive study using clinical records of patients hospitalised in the Department of Medicine in the Military Hospital of Libreville (Gabon) between January 2006 and May 2010. Clinical features were evaluated using multivariable logistic regression to evaluate association with the outcome of a clinical improvement or death.

RESULTS

The most frequent neurological symptoms were reduced level of consciousness (54.3%), headache (55.2%), motor deficit (38.7%), and convulsions (36.2%). Cerebral toxoplasmosis represented 64.7% of diagnoses, followed by cryptococcal neuromeningitis in 12.9% of cases. Tuberculoma was diagnosed in 4 cases and lymphoma in 2 cases. In 9.5% of cases, no aetiology was determined. Toxoplasmosis treatment led to clinical improvement in 69.3% of cases with suspected cerebral toxoplasmosis. Overall mortality was 39.7%.

CONCLUSION

The diagnosis of neurological conditions in HIV positive patients is difficult, particularly in a low-resource setting. A trial of treatment for toxoplasmosis should be initiated first line with all signs of neurological pathology in a patient infected with HIV.

Genetic characterization of Toxoplasma gondii from autopsy proven cases of AIDS associated cerebral toxoplasmosis in South India

Toxoplasma gondii (T.gondii) infection can be devastating in the immunodeficient causing high morbidity and mortality. Due to limited availability of both diagnostic facilities and Highly Active Antiretroviral Therapy (HAART), toxoplasmosis continues to be a significant problem amongst Acquired Immuno Deficiency Syndrome (AIDS) patients in India. While scanty literature is available on T. gondii isolates in animals in India, little is known about the genetic diversity of the parasite in humans. Therefore, the present study investigated the genetic diversity of T. gondii in 25 confirmed cases of cerebral toxoplasmosis developing on the background of human immunodeficiency virus (HIV) infection/AIDS. PCR DNA sequencing was performed at four important genetic loci of T. gondii: BTUB, GRA6, alternative SAG2 (alt SAG2) and SAG3 on DNA from tissues obtained at postmortem. The amplified products from all the cases were successfully sequenced except at one locus for one case. Results of the present study suggest that majority of the patients (22/25; 88%) in South India are infected with strains that are recombinants of type II/III and/or strains representing T. gondii different from the archetypal lineages I, II, and III. In addition, clonal types III, MAS, and MAS variant genotypes were encountered. No clonal type I or II was seen in the present study. In addition, variants were observed at alt SAG2 and SAG3 but BTUB and GRA6 were highly conserved. Single nucleotide polymorphisms were observed mainly at two loci which are coding for surface antigens at alt SAG2 and SAG3. In conclusion, the present study reveals genetic diversity in India amongst strains of T. gondii from clinical cases of toxoplasmosis which is in accordance with other recent studies showing a high rate of genetic diversity in this parasite across the globe. There is a need to genotype T. gondii from different forms of toxoplasmosis in humans in India.

Toxoplasma gondii seroprevalence: 30-year trend in an HIV-infected US military cohort

To determine if Toxoplasma gondii IgG antibody prevalence is declining in HIV-infected persons, we analyzed data (1984-2013) from the US Military HIV Natural History Study. We found that T. gondii seroprevalence at enrollment was associated with age and decreased significantly after 1995 (P=0.004), similar to the general US population.

The Effect of Latent Toxoplasma gondii Infection on the Immune Response in HIV-Infected Patients

A relationship between latent toxoplasmosis and the immune system during HIV disease is poorly understood. Therefore, the aim of this follow-up study was to characterize immunological parameters in HIV-infected patients with latent toxoplasmosis and noninfected individuals. A total of 101 HIV-infected patients were enrolled in the study. The patients were classified into two groups based on anti-Toxoplasma gondii antibodies: a group of 55 toxoplasma-positive persons (TP) and a group of 46 toxoplasma-negative persons (TN). Absolute counts of several lymphocyte subsets decreased in the TP group, namely, T cells (p = 0.007), B cells (p = 0.002), NK cells (p = 0.009), CD4 T cells (p = 0.028), and CD8 T cells (p = 0.004). On the other hand, the percentage of CD8 T cells expressing CD38 and HLA-DR significantly increased during the follow-up in the TP group (p = 0.003, p = 0.042, resp.) as well as the intensity of CD38 and HLA-DR expression (MFI) on CD8 T cells (p = 0.001, p = 0.057, resp.). In the TN group, analysis of the kinetics of immunological parameters revealed no significant changes over time. In conclusion, the results suggest that latent T. gondii infection modulates the immune response during HIV infection.

Molecular diagnosis of toxoplasmosis in immunocompromised patients: a 3-year multicenter retrospective study

Toxoplasmosis is a life-threatening infection in immunocompromised patients (ICPs). The definitive diagnosis relies on parasite DNA detection, but little is known about the incidence and burden of disease in HIV-negative patients. A 3-year retrospective study was conducted in 15 reference laboratories from the network of the French National Reference Center for Toxoplasmosis, in order to record the frequency of Toxoplasma gondii DNA detection in ICPs and to review the molecular methods used for diagnosis and the prevention measures implemented in transplant patients. During the study period, of 31,640 PCRs performed on samples from ICPs, 610 were positive (323 patients). Blood (n = 337 samples), cerebrospinal fluid (n = 101 samples), and aqueous humor (n = 100 samples) were more frequently positive. Chemoprophylaxis schemes in transplant patients differed between centers. PCR follow-up of allogeneic hematopoietic stem cell transplant (allo-HSCT) patients was implemented in 8/15 centers. Data from 180 patients (13 centers) were further analyzed regarding clinical setting and outcome. Only 68/180 (38%) patients were HIV(+); the remaining 62% consisted of 72 HSCT, 14 solid organ transplant, and 26 miscellaneous immunodeficiency patients. Cerebral toxoplasmosis and disseminated toxoplasmosis were most frequently observed in HIV and transplant patients, respectively. Of 72 allo-HSCT patients with a positive PCR result, 23 were asymptomatic; all were diagnosed in centers performing systematic blood PCR follow-up, and they received specific treatment. Overall survival of allo-HSCT patients at 2 months was better in centers with PCR follow-up than in other centers (P < 0.01). This study provides updated data on the frequency of toxoplasmosis in HIV-negative ICPs and suggests that regular PCR follow-up of allo-HSCT patients could guide preemptive treatment and improve outcome.

HIV-1 Tat inhibits phagocytosis by preventing the recruitment of Cdc42 to the phagocytic cup

Most macrophages remain uninfected in HIV-1-infected patients. Nevertheless, the phagocytic capacity of phagocytes from these patients is impaired, favouring the multiplication of opportunistic pathogens. The basis for this phagocytic defect is not known. HIV-1 Tat protein is efficiently secreted by infected cells. Secreted Tat can enter uninfected cells and reach their cytosol. Here we found that extracellular Tat, at the subnanomolar concentration present in the sera of HIV-1-infected patients, inhibits the phagocytosis of Mycobacterium avium or opsonized Toxoplasma gondii by human primary macrophages. This inhibition results from a defect in mannose- and Fcγ-receptor-mediated phagocytosis, respectively. Inhibition relies on the interaction of Tat with phosphatidylinositol (4,5)bisphosphate that interferes with the recruitment of Cdc42 to the phagocytic cup, thereby preventing Cdc42 activation and pseudopod elongation. Tat also inhibits FcγR-mediated phagocytosis in neutrophils and monocytes. This study provides a molecular basis for the phagocytic defects observed in uninfected phagocytes following HIV-1 infection.

Toxoplasma encephalitis in an HIV-infected patient on highly active antiretroviral therapy despite sustained immune response

Toxoplasma encephalitis (TE) is usually diagnosed in advanced stages of HIV infection when the CD4+ count is <100–200 cells/µl. A 55-year-old woman with HIV/AIDS, well controlled on antiretroviral therapy (ART), CD4+ count in the 300 cells/μl range for >1 year presented with acute onset of headache, nausea and vomiting. She had been on her current ART regimen consisting of raltegravir, co-formulated emtricitabine/tenofovir and etravirine for three years and had been off Pneumocystis prophylaxis for 10 months (trimethoprim-sulfamethoxazole). Brain MRI showed multiple ring-enhancing, supratentorial and infra-tentorial parenchymal lesions suspicious for metastases. She had no other evidence of metastatic disease in her body. The possibilities of TE and primary CNS lymphoma were considered but deemed unlikely given the high CD4+ count. A brain biopsy demonstrated Toxoplasma tachyzoites. There was no evidence of lymphoma or carcinoma. Anti-toxoplasma treatment yielded good initial clinical and radiographic responses. While on TE maintenance therapy, she developed similar symptoms. Repeat MRI showed progression of lesions. Further work-up including CSF Epstein-Barr virus PCR and SPECT Th 201 imaging was not conclusive for CNS lymphoma. The patient’s clinical condition deteriorated and she died. We postulate that functional immunological dysfunction is a possible mechanism by which our patient developed TE despite demonstrating sustained immune response on ART.

Therapy and prophylaxis of opportunistic infections in HIV-infected patients: a guideline by the German and Austrian AIDS societies (DAIG/ÖAG) (AWMF 055/066)

INTRODUCTION

There was a growing need for practical guidelines for the most common OIs in Germany and Austria under consideration of the local epidemiological conditions.

MATERIALS AND METHODS

The German and Austrian AIDS societies developed these guidelines between March 2010 and November 2011. A structured Medline research was performed for 12 diseases, namely Immune reconstitution inflammatory syndrome, Pneumocystis jiroveci pneumonia, cerebral toxoplasmosis, cytomegalovirus manifestations, candidiasis, herpes simplex virus infections, varizella zoster virus infections, progressive multifocal leucencephalopathy, cryptosporidiosis, cryptococcosis, nontuberculosis mycobacteria infections and tuberculosis. Due to the lack of evidence by randomized controlled trials, part of the guidelines reflects expert opinions. The German version was accepted by the German and Austrian AIDS Societies and was previously published by the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF; German Association of the Scientific Medical Societies).

CONCLUSION

The review presented here is a translation of a short version of the German-Austrian Guidelines of opportunistic infections in HIV patients. These guidelines are well-accepted in a clinical setting in both Germany and Austria. They lead to a similar treatment of a heterogeneous group of patients in these countries.

Clinical presentation and outcome of toxoplasma encephalitis in HIV-infected patients from Zaria, Northern Nigeria: a case series of 9 patients

Toxoplasma encephalitis (TE) is the most common cause of focal deficits in patients living with HIV/AIDS. Among 257 HIV-infected adult patients seen between January 2006 and December 2010 in a tertiary hospital in Zaria, northern Nigeria, 9 (3.5%) patients had clinical, serological, and brain imaging evidence of TE. All 9 patients had CD4 count of less than 50 cells/mm(3). Of the 9 patients, 7 were antiretroviral therapy (ART)-naive, while 2 were cases of ART-induced TE-immune reconstitution inflammatory syndrome. After administering intravenous dexamethasone for cerebral decompression and specific antitoxoplasma therapy, symptoms and signs resolved in 8 patients within 4 to 14 days, but 1 patient died. Our data suggest that even in the ART era in Nigeria, TE remains a fairly common cause of morbidity among HIV-infected patients due to late HIV diagnosis and significant immunosuppression at diagnosis. Early HIV diagnosis, early initiation of highly active ART, and routine prophylaxis against TE are imperative in combating the challenge of HIV/AIDS-related TE in Nigeria.

Toxoplasma encephalitis in HIV/AIDS patients admitted to the Douala general hospital between 2004 and 2009: a cross sectional study

Background

It is estimated that about a third of the world’s population is chronically infected with Toxoplasma gondii. Toxoplasma encephalitis (TE), which occurs as a reactivation of quiescent chronic infection, is one of the leading causes of central nervous system (CNS) infection in AIDS. Its diagnosis in most centres still remains difficult. We opted to describe the clinical and radiological features of TE as well as in-hospital outcome and its associated factors.

Methods

We carried out a cross sectional study on the clinical case notes of adult patients admitted and treated for TE at the Douala General Hospital, Cameroon between January 1^st 2004 to December 31^st 2009.

Results

Of 672 patients admitted during the study period, 14.4% (97/672) had TE. The mean age was 36.9 ± 14.1 years and the median CD4 cell count was 68/mm³ (IQR): 43 – 103). Headache and fever were the most common presenting symptoms in 92.8% (90/97) and 87.6% (85/97) of patients. Annular contrast enhanced lesions were the most common brain scan finding in 81.4% (79/97) of patients. In-hospital mortality was 29.9% (29/97). Altered sensorium, presence of focal signs, neck stiffness and low CD4 cell count were factors associated with mortality. Adjusting for low CD4 count, altered sensorium remained strongly associated with fatality, adjusted odd ratio (AOR) 3.5 (95% CI 1.2 – 10.5).

Conclusion

Toxoplasma encephalitis is common among AIDS patients in Douala. Its high case fatality warrants adequate and compliant prophylactic therapy in severely immune depressed patients as well as early initiation of antiretroviral therapy in HIV-infected patients.

Critical care of persons infected with the human immunodeficiency virus

Antiretroviral therapy (ART) has transformed the prognosis for patients infected with the human immunodeficiency virus (HIV). With effective ART, these individuals can expect to live almost as long as their HIV-negative counterparts. Given that more than a million people infected with HIV currently live in the United States, the likelihood that the practicing intensivist will manage a patient infected with HIV is high. This review discusses the challenges associated with management of critically ill patients infected with HIV, including the immune reconstitution inflammatory syndrome (a complication associated with ART initiation), ART-related toxicities, and the management of some common opportunistic infections.

Hyponatremia, acute kidney injury, and mortality in HIV-related toxoplasmic encephalitis

BACKGROUND

There are no reports on hyponatremia and acute kidney injury (AKI) involved in the course of HIV-related toxoplasmic encephalitis (TE). The main objective of this study was to describe the occurrence of hyponatremia and its relationship with AKI and mortality in HIV-related toxoplasmic encephalitis (TE).

METHODS

This was a retrospective cohort study on patients with HIV-related TE. AKI was considered only when the RIFLE (risk, injury, failure, loss, end-stage) criterion was met, after the patient was admitted.

RESULTS

A total of 92 patients were included, with a mean age of 36±9 years. Hyponatremia at admission was observed in 43 patients (46.7%), with AKI developing in 25 (27.1%) patients during their hospitalization. Sulfadiazine was the treatment of choice in 81% of the cases. Death occurred in 13 cases (14.1%). Low serum sodium level correlated directly with AKI and mortality. Male gender (OR 7.89, 95% CI 1.22-50.90, p = 0.03) and hyponatremia at admission (OR 4.73, 95% CI 1.22-18.30, p = 0.02) were predictors for AKI. Independent risk factors for death were AKI (OR 8.3, 95% CI 1.4-48.2, p < 0.0001) and hyponatremia (OR 9.9, 95% CI 1.2-96.3, p < 0.0001).

CONCLUSION

AKI and hyponatremia are frequent in TE. Hyponatremia on admission is highly associated with AKI and mortality.

Epidemiology of and diagnostic strategies for toxoplasmosis

The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

Toxoplasmic encephalitis in an AIDS cohort at Puerto Rico before and after highly active antiretroviral therapy (HAART)

Highly active antiretroviral therapy (HAART) significantly reduced the toxoplasmic encephalitis (TE) incidence in acquired immunodeficiency syndrome (AIDS) patients. The TE incidence and mortality were evaluated in an AIDS cohort followed in Puerto Rico before, during, and after HAART implementation in the Island. Of the 2,431 AIDS studied patients 10.9% had TE diagnosis, with an incidence density that decreased from 5.9/100 person-years to 1.1/100 person-years after HAART. Cox proportional hazard analysis showed substantial mortality reduction among TE cases who received HAART. No mortality reduction was seen in those cases who received TE prophylaxis. Although this study shows a TE incidence and mortality reduction in the AIDS cohort after HAART, the incidence was higher than those reported in the United States AIDS patients. Poor TE prophylaxis compliance might explain the lack of impact of this intervention. Strengthening the diagnostic and opportune TE diagnosis and prompt initiation of HAART in susceptible patients is important to control this opportunistic infection.

Toxoplasmic encephalitis in AIDS-patients before and after the introduction of highly active antiretroviral therapy (HAART)

Toxoplasmic encephalitis (TE) continues to be a severe health problem despite the introduction of highly active antiretroviral therapy (HAART). To identify predictors for development of TE we compared demographic, clinical and diagnostic variables in AIDS patients with TE before (n = 102) or after the introduction (n = 70) of HAART at the Charité University Medicine in Berlin, Germany. Interestingly, patient characteristics did not differ significantly in the pre- and post-HAART groups. Sixty-eight percent of patients had CD4-cell counts of <50/μl. Outcome after treatment with pyrimethamin plus sulfonamides or clindamycin (47% each) did not differ; adverse reactions were more frequent in patients receiving sulfonamides than in those receiving clindamycin (25% vs. 10.5%; p = 0.02). Interestingly, patients in the post HAART group had not received (82.9%) or had not taken HAART adequately (17.1%). Concurrent diagnosis of TE and HIV was significantly more often in the post- compared to the pre-HAART group (49 vs. 26%, respectively; p > 0.001). Thus, despite the introduction of HAART, awareness of opportunistic infections in HIV patients is warranted. High rates of unawareness of HIV infection should make public health efforts focus on early identification of HIV infection and initiation of and compliance with HAART.

HIV-associated central nervous system diseases in the recent combination antiretroviral therapy era

BACKGROUND AND PURPOSE

Data describing the incidence and survival of HIV-related central nervous system diseases (CNS-D) in recent years are sparse.

METHODS

Between 1996 and 2007, adult subjects without previous CNS-D within a large UK cohort were included (n=30,954). CNS-D were HIV encephalopathy (HIVe), progressive multifocal leucoencephalopathy (PML), cerebral toxoplasmosis (TOXO) and cryptococcal meningitis (CRYP). Associations between demographic, clinical and laboratory parameters with incidence and survival of CNS-D were evaluated using Poisson regression analysis and Kaplan-Meier techniques.

RESULTS

Six hundred and thirteen new CNS-D occurred in 574 subjects (HIVe:187, PML:113, TOXO:184, CRYP:129). Incidence of all CNS-D declined from 13.1 per 1000 PY in 1996/1997 to 1.0 per 1000 PY in 2006/2007 (P=0.0001). Current CD4+ cell count below 200 cells/ul and plasma HIV RNA above 100,000 copies/ml were independently associated with the development of CNS-D. Calendar year 1996/1997, older age, prior AIDS diagnosis and PML diagnosis were significantly associated with shorter survival.

CONCLUSIONS

An ongoing decline in the incidence of CNS-D has been observed in very recent years. Mortality following such a diagnosis remains high.

False serologic evidence for acute primary toxoplasmosis during liver transplantation for fulminant hepatitis B: a case report

Acute primary Toxoplasma gondii infection is usually considered to be a contraindication for solid organ transplantation. Recent reports of acute T. gondii infection have highlighted the need to include T. gondii serology in the pretransplant screening of solid-organ transplant recipients. However such serology might be misleading. We describe the case of a 25-year-old woman who received a liver transplantation for life-threatening liver failure due to hepatitis B virus infection. The presence of high IgM titers against T. gondii, as detected by membrane immunoassay, immunofluorescence, and mu-capture ELISA tests, together with the absence of IgG antibodies in the immediate pretransplant serology screening suggested acute primary T. gondii infection at the time of transplantation. We initiated a preemptive therapy with intravenous clindamycin and cotrimoxazole. However, negative PCR and IgA capture assays, together with the absence of a sustained IgG response finally excluded the initial diagnosis of primary toxoplasmosis, leading to discontinuation of antitoxoplasmosis therapy. This case illustrates the problem that, in the context of fulminant hepatitis B, serologic markers for acute primary toxoplasmosis can be falsely positive. Confirmation by PCR and IgA antibody determinations is required to confirm this diagnosis.

Toxoplasma gondii infection and cerebral toxoplasmosis in HIV-infected patients

Cerebral toxoplasmosis is a major cause of morbidity and mortality among HIV-infected patients, particularly from developing countries. This article summarizes current literature on cerebral toxoplasmosis. It focuses on: Toxoplasma gondii genetic diversity and its possible relationship with disease presentation; host responses to the parasite antigens; host immunosupression in HIV and cerebral toxoplasmosis as well as different diagnostic methods; clinical and radiological features; treatment; and the direction that studies on cerebral toxoplasmosis will likely take in the future.