Azithromycin versus Sulfadiazine and Pyrimethamine for non-vision-threatening toxoplasmic retinochoroiditis: a pilot study

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

Considerations in the management of ocular toxoplasmosis in pregnancy: a review of literature

Ocular toxoplasmosis is the most common cause of infectious posterior uveitis. Available literature is still conflicting regarding the incidence of recurrence during pregnancy as various calculations were employed in the different published studies. Although earlier reports have suggested a difference in presentation and an increase in severity during pregnancy, newer studies appear to show otherwise. Further diagnostic testing, including serologic and intraocular fluid sampling, may be indicated to increase the diagnostic accuracy in this special population of patients. The management of ocular toxoplasmosis during pregnancy is challenging as the foetus is additionally considered in the choice of treatment. Traditionally preferred anti-toxoplasmosis regimens containing antifolate drugs, such as pyrimethamine and trimethoprim-sulfamethoxazole, cannot be used routinely in pregnant patients, especially during the first trimester. This review includes literature on alternative treatments for ocular toxoplasmosis during pregnancy, including spiramycin and intravitreal treatment options.

[Diagnostics and treatment of ocular toxoplasmosis : Results of a survey]

BACKGROUND

Ocular toxoplasmosis (OT) is the most common infectious cause of posterior uveitis. This survey aimed to evaluate the current diagnostic and therapeutic approach to OT in Germany.

MATERIAL AND METHODS

A detailed questionnaire with specific patient examples was sent in July 2021 to the members of the Uveitis Section of the German Ophthalmological Society (DOG) and the Retinological Society (RG).

RESULTS

The questionnaire was answered by 53 (29 RG and 24 DOG) ophthalmologists. Of the respondents 16 (30%) work in private practice, 18 (34%) in a clinical facility and 19 (36%) in university hospital, 9 (17%) colleagues see < 50, 28 (53%) 50-200 and 16 (30%) more than 200 uveitis patients per year. The clinical results are still the gold standard (87%) for the diagnosis of OT and in cases of first manifestation 60% are supported by serological antibody investigations, while 10 out of 53 (19%) ophthalmologists rely on the clinical presentation only. An IgM test is requested by 25 (47%) respondents, 6 expected an increase in IgG titer (11%) and 1 the detection of specific IgA antibodies (2%). The majority (n = 28, 53%) of ophthalmologists would aim at confirming the diagnosis by an anterior chamber puncture, from which 20 (38%) prefer PCR, 3 (6%) determination of Goldmann-Witmer coefficients (GW) and 5 (9%) a combination of both methods. Clindamycin was most frequently used for treatment (n = 21, 40%), followed by pyrimethamine/sulfadiazine (n = 17, 32%) and trimethoprime + sulfamethoxazole (TMP/SMX) (n = 10, 19%); the latter was also used (n = 40, 75%) for secondary prophylaxis.

CONCLUSION

The results show that apart from the clinical results as the gold standard for the diagnosis, there is no uniform approach to diagnosis and treatment of OT. The high request rate for serum IgM antibodies indicates a widespread uncertainty about the importance of serological findings. This should be viewed critically, given the continued high seroprevalence in Germany.

Ocular Toxoplasmosis: No Stranger to the Masquerade Ball

Purpose:

This article illustrates multiple atypical manifestations of ocular toxoplasmosis masquerading as acute retinal necrosis and vitreoretinal lymphoma.

Methods:

Two case presentations are discussed, and the body of pertinent literature is reviewed and discussed.

Results:

In these cases, an extensive workup and attention to history lead to the correct diagnosis and management.

Conclusions:

Aggressive cases of ocular toxoplasmosis may present in a variety of phenotypes that may mimic other vision- and potentially life-threatening conditions, particularly in a milieu of inadequate endogenous and exogenous antimicrobial defenses.

Comparison between the areas of scarred and active toxoplasmic retinochoroiditis

BACKGROUND/OBJECTIVES

To assess the ratio of scarred/active areas of fundus lesions in patients with presumed ocular toxoplasmosis.

SUBJECTS/METHODS

Retrospective monocentric study of patients with presumed ocular toxoplasmosis seen between May 2004 and February 2018. Patients with a positive anti-Toxoplasma serology presenting characteristic fundus lesions. Cases with images of both baseline active and scarred lesions of the fundus were included. The borders of each active or scarred lesion were delineated on colour photographs by two independent observers and the area of the lesions was calculated using Digimizer 4.2.2 (MedCalc Software, Ostend, Belgium). The interobserver variability of the measures was recorded and their means were used for further calculations. To study the ratio of the area of scarred retinochoroiditis over the area of the baseline active lesion (R).

RESULTS

A total of 171 cases (83 males, 88 females) with a mean age of 31.6 ± 13.8 years were included. The average areas of active and scarred retinochoroiditis were, respectively, 1.32 ± 1.59 and 1.79 ± 2.36 optic disc area. The average ratio between scarred and active areas of retinochoroiditis was 1.36 [range 0.54-2.18]. The administration of a systemic treatment [R = 1.25, p = 0.003], the absence of a pre-existing scar [R = 1.05, p < 0.001] and a peripapillary location of the lesion [R = 0.85, p < 0.001] were each significantly associated with smaller scarred/active area ratios.

CONCLUSIONS

We assessed in a standardized manner the ratio of scarred/active areas of toxoplasmic lesions and showed that the area of scarred lesions was on average slightly larger than the area of active retinochoroiditis.

Safety and efficacy of different antibiotic regimens in patients with ocular toxoplasmosis: systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis (OT) is the most common cause of posterior uveitis, which leads to visual impairment in a large proportion of patients. Antibiotics and corticosteroids lower the risk of permanent visual loss by controlling infection and inflammation. However, there remains disagreement regarding optimal antibiotic therapy for OT. Therefore, this systematic review and meta-analysis were performed to determine the effects and safety of existing antibiotic treatment regimens for OT.

METHODS

MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, LILACS, WHO International Clinical Trials Registry Platform portal, ClinicalTrials.gov, and Gray Literature in Europe ("OpenGrey") were searched for relevant studies; manual searches of reference lists were performed for studies identified by other methods. All published and unpublished randomized controlled trials that compared antibiotic schemes known to be effective in OT at any dosage, duration, and administration route were included. Studies comparing antibiotics with placebo were excluded. This review followed standard methodological procedures recommended by the Cochrane group.

RESULTS

Ten studies were included in the narrative summary, of which four were included for quantitative synthesis (meta-analysis). Interventions were organized into three groups: intravitreal clindamycin versus pyrimethamine + sulfadiazine, trimethoprim + sulfamethoxazole versus other antibiotics, and other interventions. The first comparison favored intravitreal clindamycin (Mean difference (MD) = 0.10 logMAR; 95% confidence interval = 0.01 to 0.22). However, this finding lacks clinical relevance. Other outcomes showed no statistically significant differences between the treatment groups. In general, the risk of performance bias was high in evaluated studies, and the quality of the evidence found was low to very low.

CONCLUSIONS

No antibiotic scheme was superior to others, and the selection of a treatment regimen depends on multiple factors; therefore, treatment should be chosen based on safety, sulfa allergies, and availability.

Treatment of toxoplasmic encephalitis with the combination of clindamycin plus azithromycin in an HIV-infected patient: A case report

The existence of alternative oral therapies could help clinicians to treat toxoplasmic encephalitis (TE) in the HIV patients. The combination of azithromycin and clindamycin may serve as an effective treatment for TE in HIV-infected patients.

Sulfadiazine Hypersensitivity and Desensitization in Children With Congenital Toxoplasmosis: A Report on Two Cases

Combination therapy for toxoplasmosis consists of sulfadiazine, pyrimethamine and leucovorin. Although sulfadiazine can cause hypersensitivity reactions, such as fever, rash and liver dysfunction, there is no consensus on an effective therapy for congenital toxoplasmosis (CTox) without sulfadiazine. We attempted desensitization to sulfadiazine in 2 patients with CTox and sulfadiazine hypersensitivity. Desensitization was achieved for 1 patient.

Control of human toxoplasmosis

Toxoplasmosis is caused by Toxoplasma gondii, an apicomplexan parasite that is able to infect any nucleated cell in any warm-blooded animal. Toxoplasma gondii infects around 2 billion people and, whilst only a small percentage of infected people will suffer serious disease, the prevalence of the parasite makes it one of the most damaging zoonotic diseases in the world. Toxoplasmosis is a disease with multiple manifestations: it can cause a fatal encephalitis in immunosuppressed people; if first contracted during pregnancy, it can cause miscarriage or congenital defects in the neonate; and it can cause serious ocular disease, even in immunocompetent people. The disease has a complex epidemiology, being transmitted by ingestion of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. In this review we examine current and future approaches to control toxoplasmosis, which encompass a variety of measures that target different components of the life cycle of T. gondii. These include: education programs about the parasite and avoidance of contact with infectious stages; biosecurity and sanitation to ensure food and water safety; chemo- and immunotherapeutics to control active infections and disease; prophylactic options to prevent acquisition of infection by livestock and cyst formation in meat; and vaccines to prevent shedding of oocysts by definitive feline hosts.

Metacytofilin Is a Potent Therapeutic Drug Candidate for Toxoplasmosis

BACKGROUND

Toxoplasmosis, a parasitic disease caused by Toxoplasma gondii, is an important cause of miscarriage or adverse fetal effects, including neurological and ocular manifestations in humans. Current anti-Toxoplasma drugs have limited efficacy against toxoplasmosis and also have severe side effects. Therefore, novel efficacious drugs are urgently needed. Here, we identified metacytofilin (MCF) from a fungal Metarhizium species as a potential anti-Toxoplasma compound.

METHODS

Anti-Toxoplasma activities of MCF and its derivatives were evaluated in vitro and in vivo using nonpregnant and pregnant mice. To understand the mode of action of MCF, the RNA expression of host and parasite genes was investigated by RNAseq.

RESULTS

In vitro, MCF inhibited the viability of intracellular and extracellular T. gondii. Administering MCF intraperitoneally or orally to mice after infection with T. gondii tachyzoites increased mouse survival compared with the untreated animals. Remarkably, oral administration of MCF to pregnant mice prevented vertical transmission of the parasite. Interestingly, RNA sequencing of T. gondii-infected cells treated with MCF showed that MCF inhibited DNA replication and enhanced RNA degradation in the parasites.

CONCLUSIONS

With its potent anti-T. gondii activity, MCF is a strong candidate for future drug development against toxoplasmosis.

Approach to ocular toxoplasmosis including pregnant women

PURPOSE OF REVIEW

To discuss available information on the effectiveness of anti-toxoplasma therapy for ocular toxoplasmosis and to provide clinicians with a practical approach to the disease.

RECENT FINDINGS

Only eleven randomized studies were identified. In the three studies for acute retinitis, there was a clear trend in favor of treatment. In the two studies for the prevention of recurrences, trimethoprim-sulfamethoxazole prophylaxis was superior to placebo. In the six studies comparing different regimens, there was no statistically significant difference between the regimens. In the setting of acute posterior uveitis suspected to be caused by toxoplasma, serological testing should always be obtained, and anti-toxoplasma drug treatment, and corticosteroids should be instituted for at least 6 weeks. Toxoplasmic chorioretinitis during pregnancy represents a particular challenge.

SUMMARY

Treatment with at least two drugs and corticosteroids should be offered to patients with active toxoplasmic chorioretinitis. Pregnant women with confirmed acute infection and concomitant acute retinitis should be treated for the ocular lesion(s) and to prevent vertical transmission. Pregnant women with chronic Toxoplasma infection acquired prior to gestation and concomitant retinitis by reactivation should be treated for the retinitis and monitored for vertical transmission.

Adverse Reactions in Antifolate-Treated Toxoplasmic Retinochoroiditis

This study seeks to define factors affecting the development of adverse reactions to intensive therapy of toxoplasmic retinochoroiditis with antifolate agents (pyrimethamine/sulfadoxine) and antibiotics followed by secondary antifolate prophylaxis. The study was of retrospective and observational nature. Medical files were reviewed of 551 patients suffering from ocular toxoplasmosis during 1994-2013. All patients were treated with the same protocol: 3-week intensive pyrimethamine/sulfadoxine plus antibiotic/steroid therapy. Three hundred and fourteen out of the 551 patients qualified for the subsequent 6-month long secondary antifolate prophylaxis. The type and occurrence rate of adverse reactions were taken into account. The probability of an adverse reaction during the intensive therapy phase was 33.4%. Hypertransaminasemia was the most common event observed in 24.6% of the patients, but it assumed a severe character in just 0.9%, with male gender and age over 25 years being the predisposing factors. Less common adverse effects included thrombocytopenia (8.3%), hypersensitivity skin reactions (3.0%), and abdominal pain (1.4%). The adverse effects of secondary antifolate prophylaxis, most commonly hypersensitivity skin reactions and hypertransaminasemia, followed by thrombocytopenia and abdominal pain, were observed in 4.9% of the patients. Ten of them (2.7%) had to discontinue the treatment while eight others continued with pyrimethamine alone without further adverse effects, which suggests that discontinuation of the sulfonamide decreased the propensity for adverse reactions. The treatment strategy in these patients differed from previous reports in that it used lower doses of pyrimethamine/sulfonamide, with no folinic acid supplementation. Nonetheless, the rate and severity of adverse events were no greater than those noticed with traditional regimens, with higher antifolate doses and folinic acid supplementation. We conclude that the dose and drug-mitigated treatment strategy we employed deserves consideration as a promising alternative to traditional treatments for ocular toxoplasmosis.

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

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

Current treatment of ocular toxoplasmosis in immunocompetent patients: a network meta-analysis

Ocular toxoplasmosis (OT) is the most frequent form of infectious posterior uveitis caused by the protozoan parasite Toxoplasma gondii. To evaluate the available evidence in peer-reviewed publications about the most effective therapy for OT in immunocompetent patients, herein a systematic literature search was conducted using Embase, PubMed, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) database from January 1987 to October 2017, with search terms "OT", "retinochoroiditis", "treatment", and "immunocompetent"; search filters "controlled clinical trial", "randomized clinical trial", and "clinical trial". The included studies were performed to evaluate the various treatment modalities of OT. Different treatment regimens were compared with regard to the improvement of visual acuity, the resolution of vitreous inflammation, recurrence, and side-effects. We independently extracted data and assessed eligibility and risk of bias using the preferred reporting items for systematic reviews and meta-analysis, and resolved any disagreement through discussion. A Bayesian network meta-analysis model was used to evaluate the interesting outcomes of all the interventions. Total 10 trials of treatments for OT were found to meet the inclusion criteria. Six trials of treatments including clindamycin, azithromycin, and trimethoprim-sulfamethoxazole (TMP-SMX) were compared with conventional therapy (the combination of pyrimethamine, sulfadiazine, and corticosteroids) for evaluation of the effect on visual acuity, vitreous inflammation, recurrence of OT, and side-effects. Two trials were compared TMP-SMX with placebo. One trial was compared azithromycin with TMP-SMX. And another trial was compared among treatments with clindamycin, P-S, TMP-SMX, and placebo. Based on our network meta-analysis, therapy with TMP-SMX seems to be an alternative treatment of OT in immunocompetent patients.

Adverse Event Profile of Pyrimethamine-Based Therapy in Toxoplasmosis: A Systematic Review

Introduction

Approximately a third of the population worldwide is chronically infected with Toxoplasma gondii. Pyrimethamine-based regimens are recommended for the treatment of toxoplasmosis.

Objective

The aim was to evaluate the safety profile of pyrimethamine-based treatment for the three main Toxoplasma manifestations: toxoplasmic encephalitis (TE), ocular toxoplasmosis, and congenital toxoplasmosis.

Methods

PubMed, Cochrane Library, and Google Scholar databases were searched through August 1, 2016. Randomized, observational, prospective/retrospective, and cohort studies were eligible. Thirty-one studies were included with a total of 2975 patients. Of these, 13 were in congenital toxoplasmosis (n = 929), 11 in ocular toxoplasmosis (n = 1284), and seven in TE (n = 687). Across manifestations, adverse event (AE)-related treatment discontinuation and/or change in therapy involved ≤37% of patients and occurred in >55% of studies: 100% for ocular toxoplasmosis, 57.1% for TE, and 61.5% for congenital toxoplasmosis. The most commonly observed AEs were bone marrow suppression, dermatologic, and gastrointestinal (GI). The prevalence of bone marrow suppression-related AEs was ≤50% in congenital toxoplasmosis, ≤42.7% in TE, and ≤9.0% in ocular toxoplasmosis. The frequency of GI and dermatologic AEs were ≤100 and ≤11.1%, respectively, for ocular toxoplasmosis, ≤10.7 and ≤17.9% for TE, and ≤10.8 and ≤2.1% for congenital toxoplasmosis. Steven–Johnson syndrome was reported in two patients with ocular toxoplasmosis and one with TE.

Conclusion

The AE profile associated with pyrimethamine-based treatments differed by each manifestation of toxoplasmosis and within a given manifestation. Hematologic AEs occurred across all manifestations indicating the importance of monitoring the blood of patients administered pyrimethamine-based regimens.

Corticosteroids as adjuvant therapy for ocular toxoplasmosis

BACKGROUND

Ocular infection caused by Toxoplasma gondii, a parasite, may result in inflammation in the retina, choroid, and uvea, and consequently lead to complications such as glaucoma, cataract, and posterior synechiae.

OBJECTIVES

The objective of this systematic review was to assess the effects of adjunctive use of corticosteroids to anti-parasitic therapy versus anti-parasitic therapy alone for ocular toxoplasmosis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register (2016; Issue 11)), MEDLINE Ovid, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, MEDLINE Ovid Daily (January 1946 to December 2016), Embase (January 1980 to December 2016), Latin American and Caribbean Literature on Health Sciences (LILACS (January 1982 to December 2016)), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 7 December 2016.

SELECTION CRITERIA

We had planned to include randomized and quasi-randomized controlled trials. Eligible trials would have enrolled participants of any age who were immunocompetent and were diagnosed with acute ocular toxoplasmosis. Included trials would have compared anti-parasitic therapy plus corticosteroids versus anti-parasitic therapy alone, different doses or times of initiation of corticosteroids.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles and abstracts retrieved through the electronic searches. We retrieved full-text reports of studies categorized as 'unsure' or 'include' after we reviewed the abstracts. Two authors independently reviewed each full-text report for eligibility. Discrepancies were resolved through discussion.

MAIN RESULTS

We identified no completed or ongoing trial that was eligible for this Cochrane review.

AUTHORS' CONCLUSIONS

Although research has identified a wide variation in practice regarding the use of corticosteroids, our review did not identify any evidence from randomized controlled trials for or against the role of corticosteroids in the management of ocular toxoplasmosis. Several questions remain unanswered by well-conducted randomized trials in this context, including whether the use of corticosteroids as an adjunctive agent is more effective than the use of anti-parasitic therapy alone; if so, when corticosteroids should be initiated in the treatment regimen (early versus late course of treatment), and what would be the best dose and duration of steroid use.

A prospective randomized trial of azithromycin versus trimethoprim/sulfamethoxazole in treatment of toxoplasmic retinochoroiditis

Purpose

To assess the efficacy of oral azithromycin in the treatment of toxoplasmic retinochoroiditis.

Methods

A randomized interventional comparative study was conducted on 14 patients with ocular toxoplasmosis who were treated with oral azithromycin and 13 patients who were treated with oral trimethoprim/sulfamethoxazole for 6–12 weeks. The achievement of treatment criteria in the two groups and lesion size reduction were considered as primary outcome measures.

Results

The resolution of inflammatory activity, decrease in the size of retinochoroidal lesions, and final best corrected visual acuity (BCVA) did not differ between the two treatment groups. The lesion size declined significantly in all patients (P = 0.001). There was no significant difference in the reduction of the size of retinal lesions between the two treatment groups (P = 0.17).

Within each group, there was a significant improvement in BCVA after treatment; BCVA increased by 0.24 logMAR in the azithromycin group (P = 0.001) and by 0.3 logMAR in the trimethoprim/sulfamethoxazole group (P = 0.001).

Conclusions

Drug efficacy in terms of reducing the size of retinal lesions and visual improvement was similar in a regimen of trimethoprim/sulfamethoxazole or azithromycin treatment. Therefore, if confirmed with further studies, therapy with azithromycin seems to be an acceptable alternative for the treatment of ocular toxoplasmosis.

Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period and lactation: clinical observations

Background

During pregnancy and labor, the immune response is physiologically impaired and women are more susceptible to infections. Since many drugs may have potentially adverse effects on the fetus and newborn, less aggressive treatment regimens should be considered in pregnant and lactating patients. The aim of our study was to present the management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, and lactation.

Material/Methods

A retrospective study was undertaken of the clinical records of 24 women during pregnancy, postpartum period, and lactation who were referred in the years 1994–2014 to the Department of Zoonoses and Tropical Diseases or the Department of Ophthalmology, Medical University of Warsaw for toxoplasmic retinochoroiditis. The diagnosis was based on the typical ophthalmoscopic picture, confirmed by serological testing using an ELISA method.

Results

A total of 28 attacks of toxoplasmic retinochoroiditis were observed in 24 patients during pregnancy, postpartum period, and lactation. The choice of treatment was guided by the character and location of the inflammatory lesion and the gestational age. Topical (steroidal/nonsteroidal eye drops) and systemic treatments with spiramycin or azithromycin, Fansidar (pyrimethamine 25 mg/sulfadoxine 500 mg), and prednisone were used.

Conclusions

Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, or lactation must be individualized and guided by the gestational age and location of the active lesion. Women of childbearing age with toxoplasma ocular lesions should be informed by their doctors about possible active recurrences during pregnancy and followed carefully by an ophthalmologist when pregnant.

Current treatment of toxoplasma retinochoroiditis: an evidence-based review

Objective. To perform an evidence-based review of treatments for Toxoplasma retinochoroiditis (TRC). Methods. A systematic literature search was performed using the PubMed database and the key phrase "ocular toxoplasmosis treatment" and the filter for "controlled clinical trial" and "randomized clinical trial" as well as OVID medline (1946 to May week 2 2014) using the keyword ''ocular toxoplasmosis". The included studies were used to evaluate the various treatment modalities of TRC. Results. The electronic search yielded a total of 974 publications of which 44 reported on the treatment of ocular toxoplasmosis. There were 9 randomized controlled studies and an additional 3 comparative studies on the treatment of acute TRC with systemic or intravitreous antibiotics or on reducing the recurrences of TRC. Endpoints of studies included visual acuity improvement, inflammatory response, lesion size changes, recurrences of lesions, and adverse effects of medications. Conclusions. There was conflicting evidence as to the effectiveness of systemic antibiotics for TRC. There is no evidence to support that one antibiotic regimen is superior to another so choice needs to be informed by the safety profile. Intravitreous clindamycin with dexamethasone seems to be as effective as systemic treatments. There is currently level I evidence that intermittent trimethoprim-sulfamethoxazole prevents recurrence of the disease.

Antibiotics for human toxoplasmosis: a systematic review of randomized trials

The efficacy of different treatment regimens in clinical syndromes of toxoplasmosis were assessed by conducting a systematic review of published randomized clinical trials through extensive searches in MEDLINE, EMBASE, and SCOPUS with no date limits, as well as manual review of journals. Outcome measures varied depending on the clinical entity of toxoplasmosis. Risk of bias was evaluated and quality of evidence was graded. Fourteen randomized trials were included of which one was a non-comparative study. One well-designed trial showed that trimethoprim-sulphamethoxazole was more effective than placebo for clinical recovery of toxoplasmic lymphadenopathy in immunocompetent hosts. For toxoplasmic encephalopathy, efficacy of pyrimethamine+sulphadiazine and trimethoprim+sulphamethoxazole were similar, whereas pyrimethamine+sulphadiazine versus pyrimathamine+clindamycin showed no difference, irrespective of the outcome. Intravitreal clindamycin+dexamethasone and conventional treatment with oral pyrimethamine+sulphadiazine had similar efficacy with regard to all outcome measures in ocular toxoplasmosis, and intravitreal therapy was found to be safe. Adverse effects seemed more common with pyrimethamine+sulphadiazine. Most trials for encephalitis and ocular manifestations had a high risk of bias and were of poor methodological quality. There were no trials evaluating drugs for toxoplasmosis in pregnancy, or for congenital toxoplasmosis. Pyrimethamine+sulphadiazine is an effective therapy for treatment of toxoplasmic encephalitis; trimethoprim+sulphamethoxazole and pyrimethamine+clindamycin are possible alternatives. Treatment with either oral or intravitreal antibiotics seems reasonable for ocular toxoplasmosis. Overall, trial evidence for the efficacy of these drugs for toxoplasmosis is poor, and further well-designed trials are needed.

Ocular Toxoplasmosis: Controversies in Primary and Secondary Prevention

Ocular toxoplasmosis is the most common cause of posterior uveitis in the United States and worldwide. It commonly follows a relapsing course with the potential for multiple adverse visual sequelae and, rarely, blindness. Both immune-competent and immune-suppressed populations can develop severe relapsing disease. There is considerable debate regarding the initial treatment of ocular toxoplasmosis in both groups, with multiple antiparasitic agents commonly used with little evidence to support any particular regimen. The precise role of corticosteroids in treatment also has yet to be rigorously defined. Secondary prevention is commonly implemented in the immune suppressed population, but there is a lack of level one evidence to support its role in immune-competent patients, though it warrants future investigation.

A systematic review and meta-analysis of Toxoplasma gondii infection among the Mexican population

BACKGROUND

Toxoplasmosis is a disease caused by Toxoplasma gondii and at least one-third of the world's population has detectable T. gondii antibodies. The seroprevalence of T.gondii ranges from 15% to 50% among the Mexican general population. The aim of this work was to determine the mean prevalence and weighted mean prevalence of T. gondii infection, and to evaluate the epidemiological transition of infection in Mexico.

METHODS

Pub Med, Lilacs, Medline, Latindex, Google Scholar data bases were searched to retrieve reports from 1951 up to 2012 regarding prevalence data, diagnostic tests and risk factors of infection among the adult population. Data collection and criteria eligibility was established in order to determine the crude prevalence (proportion of positive cases) of each study, together with weighted population prevalence according to individual research group categories to limit the bias that may impose the heterogeneous nature of the reports. A Forest Plot chart and linear regression analysis were performed by plotting the prevalence of infection reported from each study over a period of sixty years.

RESULTS

A total of 132 studies were collected from 41 publications that included 70,123 individuals. The average mean prevalence was 27.97%, and weighted mean prevalence was 19.27%. Comparisons among different risk groups showed that the weighted prevalence was higher in women with miscarriages (36.03%), immunocompromised patients (28.54%), mentally-ill patients (38.52%) and other risk groups (35.13%). Toxoplasma infection among the Mexican population showed a downward trend of 0.1%/year over a period of sixty years that represents a 5.8% reduction in prevalence.

CONCLUSIONS

This analysis showed a downward trend of infection; however, there are individuals at high risk for infection such as immunocompromised patients, mentally-ill patients and pregnant women. Further research is required to provide better prevention strategies, effective diagnostic testing and medical management of patients. Educational efforts are required to avoid the transmission of infection in populations that cannot be controlled by drugs alone.