Socioeconomic vulnerability associated to Toxoplasma gondii exposure in southern Brazil

Risk factors for toxoplasmosis in people living with HIV in the Asia-Pacific region

INTRODUCTION

Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific.

METHODS

This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression.

RESULTS

A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28-38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/μL and 162 (78.6%) had CD4 ≤100 cells/μL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81-7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15-4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41-7.21). Toxoplasmosis was less likely with increasing CD4 counts (51-100 cells/μL: OR 0.41, 95% CI 0.18-0.96; 101-200 cells/μL: OR 0.14, 95% CI 0.06-0.34; >200 cells/μL: OR 0.02, 95% CI 0.01-0.06), when compared to CD4 ≤50 cells/μL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis.

CONCLUSIONS

Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.

One Health Approach to Toxoplasmosis: Owner and Dog Seropositivity as Spatial Indicators of Risk Areas for Acquired, Gestational and Congenital Transmission

BACKGROUND

Toxoplasmosis has been of public health concern due to direct associations with socioeconomic vulnerability and inadequate living conditions.

METHODS

Accordingly, the present study aimed to assess antibodies against T. gondii, historical reported toxoplasmosis cases and associated socio-environmental risk factors in Pinhais, a full urban area of Curitiba, currently the eighth biggest metropolitan area of Brazil. Anti-Toxoplasma gondii antibodies were assessed by an indirect immunofluorescence reaction (RIFI). Owner and dog samples were also tested by IFAT to anti-Leishmania spp. and anti-Trypanosoma cruzi antibodies.

RESULTS

Overall, 20/135 (14.8%) persons and 13/133 (9.8%) dogs from 25 different households were considered seropositive to T. gondii. All samples were seronegative to Leishmania spp. and Trypanosoma cruzi.

CONCLUSIONS

Although no significant covariates were found in the regression model, statistically associated risk factors in the bivariate analysis included no public water use (p = 0.016) and drinking raw milk (p = 0.041) for owners, and obesity (p = 0.028) and tick infestation (p = 0.03) for dogs. In addition, a spatial cluster of T. gondii seropositivity for both owners and their dogs overlapped the location of historic reported cases of human acquired, gestational and congenital toxoplasmosis. Finally, the results herein showed tick infestation as an indicator of socio-environmental risk for T. gondii exposure in the household environment, and dogs may be used as sentinels for human toxoplasmosis cases.

Chronic Stress Indicator: A Novel Tool for Comprehensive Stress Analysis

Extensive research has highlighted the strong association between chronic stress and negative health outcomes. This relationship is influenced by various factors, including sociobehavioral, environmental, and genetic and epigenomic forces. To comprehensively assess an individual's stress levels, we propose the development of the Chronic Stress Indicator (CSI), a novel comprehensive multifaceted tool that incorporates key biological, anthropometric, behavioral, and socioeconomic factors. The objective of this study is to assess the effectiveness of the CSI compared to Allostatic Load (AL), a type of chronic stress, in identifying health issues related to stress. The objective of this research is to evaluate the performance of the Chronic Stress Indicator (CSI) versus Allostatic Load (AL) in detecting adverse health outcomes within the U.S. demographic aged 20-49. The information used for this study was sourced from the National Health and Nutrition Examination Survey (NHANES), carried out from 2001 to 2004. Logistic regression modeling was employed to calculate odds ratios and confidence intervals. The Wilcoxon rank-sum test was employed to assess differences in means, whereas the chi-square test, accompanied by Cramer's V statistic, was used to examine the association among categorical variables. Additionally, the relationship between continuous variables was analyzed using Pearson's correlation coefficient. Our association tests show that the length of occupation activity and health status were among the strongest associations to CSI risk. Based on our logistic regression models, age and sex were found to be significant factors in determining AL. We also found that age, smoking, and longest occupation activity were significant factors of CSI risk. These findings suggest a need for individuals to limit smoking as it may lead to higher overall stress despite its common use as a coping mechanism for stress. We should also review the level of occupational activity a job has before continuously working on it as this may also lead to higher cumulative stress.

Toxoplasmosis Behind Bars: One Health Approach on Serosurvey Dynamics and Associated Risk Factors for Women Inmates, Correctional Officers, and In-Prison Feral Cats

Brazil holds the third highest general and fifth female incarcerated population worldwide. Despite the incarceration ecosystem that may favor the spreading of zoonotic diseases, particularly when unattended animals are present, no comprehensive study has focused on toxoplasmosis dynamics in such environment. Accordingly, the present study has aimed to serologically assess anti-Toxoplasma gondii (IgG) antibodies by indirect immunofluorescent antibody test in inmates, correctional officers, and feral cats at the Women's State Penitentiary of Parana, southern Brazil. In overall, 230/506 (45.5%; CI 95%: 41.2-49.8) incarcerated women, 31/91 (34.1%; 95% CI: 25.2-44.3) correctional officers, and 23/39 (59.0%; CI 95%: 43.2-72.9) cats were seropositive to anti-T. gondii antibodies. Logistic regression revealed that seropositivity likelihood increased with consumption of raw meat (p=0.040) and decreased with elementary educational level (p=0.001). No statistical difference was found comparing seropositivity between inmates and correctional officers (p=0.057). As women inmates have been considered among the most vulnerable groups in disease morbidity and mortality, seropositivity observed herein may be directly related to vulnerability and high T. gondii oocyst exposure dispersed in cat feces during incarceration.

Gene-environment interactions and preterm birth predictors: A Bayesian network approach

Preterm birth (PTB) is the main condition related to perinatal morbimortality worldwide. The aim of this study was to identify gene-environment interactions associated with spontaneous PTB or its predictors. We carried out a retrospective case-control study including parental sociodemographic and obstetric data as well as newborn genetic variants of 69 preterm and 61 at term newborns born at a maternity hospital from Tucumán, Argentina, between 2005 and 2010. A data-driven Bayesian network including the main PTB predictors was created where we identified gene-environment interactions. We used logistic regressions to calculate the odds ratios and confidence intervals of the interactions. From the main PTB predictors (nine exposures and six genetic variants) we identified an interaction between low neighbourhood socioeconomic status and rs2074351 (PON1, genotype GG) variant that was associated with an increased risk of toxoplasmosis (odds ratio 12.51, confidence interval 95%: 1.71 - 91.36). The results of this exploratory study suggest that structural social disparities could influence the PTB risk by increasing the frequency of exposures that potentiate the risk associated with individual characteristics such as genetic traits. Future studies with larger sample sizes are necessary to confirm these findings.

Prevalence of Toxoplasma gondii IgG Antibodies and Associated Risk Factors in Psychiatric Patients from Western Romania: A Cross-Sectional Study

Infection with the coccidian parasite Toxoplasma gondii was associated with an increased risk of several mental disorders. We conducted a case-control study of 464 consecutive psychiatric patients and assessed the prevalence of IgG antibodies against T. gondii and the potential risk factors associated with infection. T. gondii-specific antibodies were determined using a chemiluminescence assay. A questionnaire was utilized to assess the potential correlation between risk factors and Toxoplasma gondii seropositivity. IgG antibodies were found in 325 (70.04%) of the patients. We observed a higher likelihood of positive IgG antibodies against Toxoplasma gondii in older individuals, patients residing in rural areas, and females. We also noted associations between Toxoplasma gondii infection and certain risk factors, like activities that involve contact with soil, low-income levels, and limited educational attainment. Our findings indicate a high prevalence of T. gondii infection among psychiatric patients from Western Romania and provide new information regarding the potential risk factors associated with T. gondii in this population group. This study may serve as a foundation for future research and the development of preventive strategies.

A review on nonviral, nonbacterial infectious agents toxicity involved in neurodegenerative diseases

Neuronal death, decreased activity or dysfunction of neurotransmitters are some of the pathophysiological reasons for neurodegenerative diseases like Alzheimer's, Parkinson's and multiple sclerosis. Also, there is evidence for the role of infections and infectious agents in neurodegenerative diseases and the effect of some metabolites in microorganisms in the pathophysiology of these diseases. In this study, we intend to evaluate the existing studies on the role of infectious agents and their metabolites on the pathophysiology of neurodegenerative diseases. PubMed, Scopus, Google Scholar and Web of Science search engines were searched. Some infectious agents have been observed in neurodegenerative diseases. Also, isolations of some fungi and microalgae have an improving effect on Parkinson's and Alzheimer's.

Guidelines for the purification and characterization of extracellular vesicles of parasites

Parasites are responsible for the most neglected tropical diseases, affecting over a billion people worldwide (WHO, 2015) and accounting for billions of cases a year and responsible for several millions of deaths. Research on extracellular vesicles (EVs) has increased in recent years and demonstrated that EVs shed by pathogenic parasites interact with host cells playing an important role in the parasite's survival, such as facilitation of infection, immunomodulation, parasite adaptation to the host environment and the transfer of drug resistance factors. Thus, EVs released by parasites mediate parasite-parasite and parasite-host intercellular communication. In addition, they are being explored as biomarkers of asymptomatic infections and disease prognosis after drug treatment. However, most current protocols used for the isolation, size determination, quantification and characterization of molecular cargo of EVs lack greater rigor, standardization, and adequate quality controls to certify the enrichment or purity of the ensuing bioproducts. We are now initiating major guidelines based on the evolution of collective knowledge in recent years. The main points covered in this position paper are methods for the isolation and molecular characterization of EVs obtained from parasite-infected cell cultures, experimental animals, and patients. The guideline also includes a discussion of suggested protocols and functional assays in host cells.

One Health Approach in Serosurvey of Toxoplasma gondii in Former Black Slave (Quilombola) Communities in Southern Brazil and Among Their Dogs

Brazilian quilombos are rural semi-isolated remnant communities of former black slaves and their descendants who traditionally maintained themselves through archaic subsistence livestock and agriculture practices and historically lacked specific public health policies. Although such individuals and their dogs may be exposed to zoonotic pathogens such as Toxoplasma gondii, no study to date has assessed these human-animal populations together. Populations in four different Brazilian quilombos in southern Brazil were evaluated. Overall, 93/208 people (44.7%) and 63/100 dogs (63.0%) were seropositive for IgG anti-T. gondii antibodies by indirect immunofluorescent antibody test (IFAT), 4/208 (1.9%) human samples seropositive for IgM anti-T. gondii antibodies, with a human-dog seropositivity ratio for IgG of 0.71. Quilombola individuals ingesting game meat were 2.43-fold more likely (95% CI: 1.05-5.9) to be seropositive. No risk factors were associated with seropositivity among dogs, thus suggesting that their exposure to T. gondii was random. Surprisingly, our research group had previously found an inverted human-dog ratio for T. gondii seropositivity of 2.54 in the urban area of a nearby major city. Because consumption of raw/undercooked game meat by quilombola individuals may have contributed to higher exposure, higher overall seroprevalence among dogs may have also indicated interaction with wildlife. Although these dogs may hunt wildlife without their owners' awareness, the higher dog seropositivity may also be related to feeding from discarded food in the community or backyard livestock animals and drinking surface water contaminated with oocysts. Thus, wildlife cannot be singled out as the reason, and future studies should consider sampling water, soil, wildlife, and livestock tissues, to fully establish the source of infection in dogs herein.

Protein kinases on carbon metabolism: potential targets for alternative chemotherapies against toxoplasmosis

The apicomplexan parasite Toxoplasma gondii is the causative agent of toxoplasmosis, a global disease that significantly impacts human health. The clinical manifestations are mainly observed in immunocompromised patients, including ocular damage and neuronal alterations leading to psychiatric disorders. The congenital infection leads to miscarriage or severe alterations in the development of newborns. The conventional treatment is limited to the acute phase of illness, without effects in latent parasites; consequently, a cure is not available yet. Furthermore, considerable toxic effects and long-term therapy contribute to high treatment abandonment rates. The investigation of exclusive parasite pathways would provide new drug targets for more effective therapies, eliminating or reducing the side effects of conventional pharmacological approaches. Protein kinases (PKs) have emerged as promising targets for developing specific inhibitors with high selectivity and efficiency against diseases. Studies in T. gondii have indicated the presence of exclusive PKs without homologs in human cells, which could become important targets for developing new drugs. Knockout of specific kinases linked to energy metabolism have shown to impair the parasite development, reinforcing the essentiality of these enzymes in parasite metabolism. In addition, the specificities found in the PKs that regulate the energy metabolism in this parasite could bring new perspectives for safer and more efficient therapies for treating toxoplasmosis. Therefore, this review provides an overview of the limitations for reaching an efficient treatment and explores the role of PKs in regulating carbon metabolism in Toxoplasma, discussing their potential as targets for more applied and efficient pharmacological approaches.

Molecular evidence of toxoplasmosis in people living with HIV in Pakistan

BACKGROUND

Toxoplasma gondii is a zoonotically important parasite infecting almost all vertebrates. The parasite can easily infect humans through the fecal-oral route, particularly immunocompromised individuals, and children. Due to lack of epidemiological data regarding the occurrence of Toxoplasma gondii in people living with HIV in Pakistan, the present study was designed to estimate the prevalence of Toxoplasma gondii in people living with HIV.

METHODS

Briefly, 384 blood samples were randomly collected from people living with HIV registered under Punjab AIDS Control Program. DNA of all samples was extracted and the 18S rRNA gene of T. gondii was amplified through polymerase chain reaction (PCR) by using genus-specific primers. The amplicons were spread on 1.5% agar rose gel and visualized under gel documentation system. Then the amplicons were purified from the gel and subjected to sequence and phylogenetic analysis.

RESULTS

Overall prevalence of T. gondii was observed as 23.96%. The prevalence of T. gondii was significantly (p <0.05) higher in females and in middle age group (26-40 years). Similarly, the prevalence was significantly (p <0.05) higher in people with poor socioeconomic status, symptomatic patients, drugs users and people using unfiltered water for drinking. Furthermore, bodyweight (46-70 kg) and dry seasons also significantly (p <0.05) affected the prevalence of T. gondii.

CONCLUSIONS

Our findings illustrated a high infection rate of toxoplasmosis in people living with HIV which could be a significant cause of mortality. More studies need to be conducted for other opportunistic infections caused by parasites and other pathogens.

[Seroprevalence and risk factors for congenital toxoplasmosis in the northeastern region of ColombiaSoroprevalência e fatores de risco associados à toxoplasmose gestacional no nordeste da Colômbia]

Introduction

Toxoplasmosis is a zoonosis prevalent in one-third of the world's population, adversely affecting maternal-fetal health by causing varying degrees of damage to the fetus. Objective: To assess the seroprevalence of Toxoplasma gondii IgG and IgM antibodies and associated risk factors in first- trimester pregnant women in Cúcuta, Colombia, in 2018.

Materials and Methods

Cross-sectional and correlational study in 111 women who voluntarily participated. Specific IgM and IgG antibodies were detected by luminescence immunoassay (LIA).

Results

Total seropositivity for IgM and IgG was 19.8% and 35.1%, respectively, 11.7% was for IgM only, and 53.2% corresponded to the overall seronegativity rate for T. gondii. Risk factors (CI = 95%) such as undercooked meat consumption (54.1% of cases, OR = 1.8, p = 0.120), tap water consumption (48.6%, OR = 1.4, p = 0.421), and goat or cow raw milk consumption (39.6%, OR = 0.78, p = 0.553) were identified; in addition, living with cats (23.4%) was identified as a risk factor significantly associated with parasite seropositivity (OR = 2.8, p = 0.025).

Discussion and conclusions

Our findings showed a possible risk of primary infection in more than half of the pregnant population, given the seronegativity against the parasite. A considerable frequency of suspected cases of very recent infection was also found. In additionto being associated with a previously recognized risk factor, this fact suggests the presence of other dietary risks that should be addressed through prevention strategies during prenatal care and the need to strengthen event surveillance.

Effects of Toxoplasma gondii infection on cognition, symptoms, and response to digital cognitive training in schizophrenia

Studies indicate that neuroscience-informed digital cognitive training can remediate cognitive impairments in schizophrenia, but the factors contributing to these deficits and response to treatment remain unclear. Toxoplasma gondii is a neuroinvasive parasite linked to cognitive decline that also presents a higher prevalence in schizophrenia. Here, we compared the cognition and symptom severity of IgG seropositive (TOXO+; n = 25) and seronegative (TOXO-; n = 35) patients who participated in a randomized controlled trial of digital cognitive training. At baseline, TOXO+ subjects presented lower global cognition than TOXO- (F = 3.78, p = 0.05). Specifically, TOXO+ subjects showed worse verbal memory and learning (F = 4.48, p = 0.03), social cognition (F = 5.71, p = 0.02), and higher antibody concentrations were associated with increased negative (r = 0.42, p = 0.04) and total (r = 0.40, p = 0.04) schizophrenia symptoms. After training, the TOXO+ group showed higher adherence to the intervention (X2 = 9.31, p = 0.03), but there were no differences in changes in cognition and symptoms between groups. These findings highlight the association between seropositivity to T. gondii and deteriorated cognition and symptoms in schizophrenia. Further research is needed to assess the specific efficacy of digital cognitive training on this population.

Evaluation of the acceptability of point of care diagnostic test for prenatal toxoplasmosis (translational research phase III)

BACKGROUND

A new point of care test (POC) was developed that is promising as a tool to enhance impact of prenatal care programs for toxoplasmosis, however, no reports exist about its use or acceptability for healthcare personnel and mothers in Colombia.

METHODS

This was a translational research - phase III study of the acceptability of a new POC test (Toxoplasma ICT IgG-IgM, LDBio) for qualitative diagnosis of toxoplasmosis in 783 pregnant women and 30 health personnel in primary health care sites in the city of Armenia, Quindío (Colombia). Along with collection of the results of diagnostic POC and confirmatory test and demographic information, we evaluated acceptability through measure of the willingness, credibility, and satisfaction by using questionnaires with a Likert scale during routine prenatal care visits.

RESULTS

POC positivity was 46.5% among pregnant participants and was significantly related to socioeconomic factors, including education level (p = 0.00000000) and insurance status (p = 0.00000015). A total of 93-97% of healthcare personnel indicated agreement to positive statements regarding total satisfaction and total credibility of the LDBio test, but qualitative questions identified "Difficulty in the test procedure" as the most common response about barriers to apply the test. Greater than 90% of pregnant participants agree that POC test should be routine for all pregnant woman and permanently implemented.

CONCLUSIONS

The test had near complete acceptability. In future studies it is necessary to examine the effect of non-differentiation between IgG and IgM isotypes.

Prevention of exposure to zoonoses in rural Latin America: Social ecological factors in a diverse regional context

Zoonotic diseases have serious impacts on human health and well-being, but they are often overlooked in rural Latin America. The design of effective preventive interventions is complex and requires an integrative approach from evidence-based information analyzed through robust theoretical frameworks. We conducted a systematized literature review and qualitative framework-guided thematic analysis to identify social ecological factors affecting the prevention and exposure to zoonotic diseases. Although resources for research are limited in Latin America, we found several studies with relevant results. We extracted and interpreted 8 themes as factors affecting the prevention, transmission, and exposure to zoonosis. These themes included knowledge and misconceptions, low risk perception, gaps in knowledge and communication, psychological effect of diseases, culture and traditions, inequality, disarticulated prevention programs, and organizational responsibility. Alongside this, we compiled and present the recommendations for actions to reduce the impact of zoonoses in these populations. The factors and recommendations here presented can be adapted to inform the design and improvement of preventive programs, focused on One Health and aiming to reduce the impact of zoonotic diseases in rural settings.

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We identified relevant social and behavioural factors affecting the prevention of Zoonotic diseases in Latin America.

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Knowledge, risk perceptions, and communication quality were relevant individual factors.

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Inequity and unarticulated programs were relevant social factors.

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Characterization of the context-specific social ecology can improve the development of effective interventions.

Toxoplasmosis in Human and Animals Around the World. Diagnosis and Perspectives in the One Health Approach

Toxoplasmosis is a unique health disease that significantly affects the health of humans, domestic animals, wildlife and is present in ecosystems, including water, soil and food. Toxoplasma gondii is one of the best-adapted parasites in the word. This parasite is able to persist for long periods in its hosts, in different geographic regions of the word. This review summarizes the current literature of these themes, focusing on: (1) toxoplasmosis, a zoonotic infection; (2) One health approach and toxoplasmosis; (3) human toxoplasmosis; (4) animal toxoplasmosis; (5) toxoplasmosis diagnosis, as immunological, parasitological and molecular diagnosis; (6) T. gondii outbreaks caused by infected meat, milk and dairy products, as well as, vegetables and water consume; (7) studies in experimental models; (8) genetic characterization of T. gondii strains; (9) extracellular vesicles and miRNA; and (10) future perspectives on T. gondii and toxoplasmosis. The vast prevalence of toxoplasmosis in both humans and animals and the dispersion and resistence of T. gondii parasites in environment highlight the importance of the one health approach in diagnostic and control of the disease. Here the different aspects of the one health approach are presented and discussed.

Long-term impact of congenital toxoplasmosis on phenotypic and functional features of circulating leukocytes from infants one year after treatment onset

Changes in immune response of children with congenital toxoplasmosis (CT) regarding infection evolution and therapeutic intervention was addressed. Infants with CT presented increased counts of monocytes, CD3^-CD16^-CD56^High, CD3⁺CD56⁺ and CD4⁺ T-cells 1-year after treatment onset (TOXO_1-yearAT). Smaller numbers of CD3^-CD16^-CD56⁺ and TCRγδ⁺ T-cells were specifically observed in infants with retinochoroidal lesions (L(+)). When infants were classified based on the baseline status, expansion of CD3^-CD16^-CD56^High and CD4⁺ T-cells were observed in L(+) who had active, active/cicatricial or cicatricial lesions. Infants who had active or active/cicatricial lesions display augmented numbers of monocytes, CD3^-CD16⁺CD56⁺, CD3⁺CD56⁺, CD8⁺DR⁺ and TCRγδ⁺ T-cells and those with active/cicatricial or cicatricial at baseline displayed increase in CD14⁺CD64⁺ monocytes. Moreover, all L(+) had increased IFN-γ⁺ and IL-10⁺ CD4⁺ T-cells, while L(-) had increased ratios of TNF⁺, IFN-γ⁺ and IL-4⁺ NK-cells upon antigen-specific stimulation. Persistent alterations in leukocytes in TOXO_1-yearAT suggest long-term sequels in the immune system of infants with CT.

Rural residence remains a risk factor for Toxoplasma infection among pregnant women in a highly urbanized Brazilian area: a robust cross-sectional study

BACKGROUND

Despite high seroprevalence of asymptomatic infection in humans, toxoplasmosis can manifest as a severe systemic disease, as occurs in the congenital infection. Here we evaluate the seroprevalence of Toxoplasma infection among pregnant women in a highly urbanized area of Brazil.

METHODS

A robust seroepidemiological study was conducted using laboratory databases of anti-Toxoplasma gondii serological results together with information on age, month/year of diagnosis and place of residence of pregnant women in the public health system of the city of Juiz de Fora, Brazil.

RESULTS

Of 5895 pregnant women analysed, 54.7% showed seronegativity and 44.4% showed seropositivity for immunoglobulin G (IgG) antibodies against Toxoplasma gondii. This seropositivity rate increased to 68.3% when only considering participants from rural areas. Multivariate analysis revealed higher odds of being seropositive associated with age (odds ratio [OR] 1.06 [confidence interval {CI} 1.05 to 1.07]) and with living in rural areas (OR 2.96 [CI 1.64 to 5.36]). The spatial distribution of IgG seropositivity indicated a higher prevalence concentrated in rural and peripheral neighbourhoods.

CONCLUSIONS

This is the first report to use spatial analysis to show a cluster of Toxoplasma infection in rural and peripheral neighbourhoods of a highly urbanized municipality, which highlights the need for adequate healthcare actions to be implemented for women living in these areas.

Cross-sectional survey for Toxoplasma gondii infection in humans in Fernando de Noronha island, Brazil

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is zoonotic disease and is one of the most important foodborne parasitic diseases globally. The prevalence in humans is highly variable, being influenced by cultural habits, socioeconomic, and environmental conditions. The objective of this study was to estimate the prevalence of T. gondii infection in humans on the archipelago of Fernando de Noronha, Pernambuco State, Brazil, and to identify the risk factors associated with this infection. The seroprevalence of immunoglobulin G anti-T. gondii antibodies was 50.4% (172/341, 95% CI: 45.2%-55.7%). Factors associated with the infection were consumption of well water or rainwater (odds ratio [OR]: 2.43, p=0.020) and consumption of game meat (OR: 1.80, p=0.026). This is the first study to provide epidemiological information of T. gondii infection among the residents of the Island of Fernando de Noronha, revealing a considerable antibody seroprevalence in this population. This study provides information for the adoption of prevention and control measures in island environments.

The Potential Contribution of ABO, Lewis and Secretor Histo-Blood Group Carbohydrates in Infection by Toxoplasma gondii

The glycosyltransferases encoded by genes from the human ABO, Lewis, and Secretor histo-blood group systems synthesize part of the carbohydrate antigens in hematopoietic and non-hematopoietic tissues. The combined action of these glycosyltransferases strongly influences cell, tissue, mucosa, and exocrine secretion carbohydrate phenotypes, including those serving as habitat for mutualistic and pathogenic microorganisms. A set of reports investigated associations between Toxoplasma gondii infection and the ABO histo-blood group system, but the results are contradictory. As T. gondii uses the gastrointestinal tract as a route for infection, and in this organ, the expression of ABO, Lewis, and Secretor histo-blood group carbohydrates occurs, it is reasonable to suppose some biological relationship between them. This text reviewed association studies published in recent decades focusing on the potential contribution of the ABO, Lewis, and Secretor histo-blood group carbohydrates and infection by T. gondii.

M, Ladrón De Guevara M, Guzmán G, de la Guardia V, García A, Lucero MF, Wong D, Mcleod R, Soberon M, Caballero E. Z. Epidemiological Aspects of Maternal and Congenital Toxoplasmosis in Panama

In Panama, epidemiological data on congenital toxoplasmosis are limited, making it difficult to understand the scope of clinical manifestations in the population and factors that may increase the risk of infection. This study provides insight into the epidemiological situation of maternal and congenital toxoplasmosis in Panama and contributing information on the burden of this disease in Central America. Blood samples were collected from 2326 pregnant women and used for the detection of anti-T. gondii antibodies. A high seroprevalence (44.41%) was observed for T. gondii infection in pregnant women from different regions of Panama, with an estimated incidence rate of congenital toxoplasmosis of 3.8 cases per 1000 live births. The main risk factors associated with T. gondii infection using bivariate statistical analysis were an elementary level education and maternal age range of 34-45 years. Multivariate statistical analyses revealed that in some regions (San Miguelito, North and West regions), the number of positive cases correlated with the presence of pets, stray dogs and the consumption of poultry. In other regions (East and Metropolitan regions), the absence of pets was considered a protective factor associated with negative cases, while the presence of stray cats and the age range of 25-34 years did not represent any risk in these regions.

Evaluation of implementation of the primary, secondary and tertiary prevention measures of the Surveillance Program of Gestational and Congenital Toxoplasmosis in the city of Londrina-PR

Toxoplasmosis acquired during pregnancy is one that can lead to death or malformations of the foetus, and it is a complex disease to diagnose. The objective of the study was to evaluate the Surveillance Program of Gestational and Congenital Toxoplasmosis. To assess primary prevention, 424 pregnant women were interviewed regarding their knowledge of prevention measures in 2019. Secondary prevention measures were assessed, and the results of anti-Toxoplasma gondii serological tests were collected from pregnant women, from 2015 to 2018. In tertiary prevention measures, babies of mothers with a recent suspicion of T. gondii infection were screened to verify forwarding to the reference service. As a result, 45.5% (192/424) reported that they had received guidance from health professionals; 35.4% (68/192) changed their risk habits. The variables of schooling and age, having received prior guidance from health professionals and feline possession, proved to be significant when associated with the notions of preventive measures. 90.2% (17,423/19,319) of pregnant women had undergone serological tests to detect anti-T. gondii antibodies, but there was an excess in requests for tests and medication and only 40.6% (26/64) of the children were referred to the reference hospital. The Program presents positive results about the performance of serological screening in prenatal care; however, the dissemination of knowledge as for the prevention of toxoplasmosis and the request for tests need to be improved.

Use of a slow-release intravitreal clindamycin implant for the management of ocular toxoplasmosis

Purpose

To report the first patient with ocular toxoplasmosis treated with a slow-release biodegradable intravitreal clindamycin implant.

Observations

A 39-year-old human immunodeficiency virus (HIV)-positive woman with recurrent toxoplasmic retinochoroiditis and vitritis for whom oral medication was medically contraindicated was treated with an intravitreal slow-release clindamycin implant and three monthly intravitreal injections of clindamycin and dexamethasone. Serial ophthalmologic examinations demonstrated gradual, complete resolution of posterior uveitis and healing of the retinochoroidal lesion with cicatricial changes, as well as gradual improvement of cells in the anterior chamber. There was no significant change in electroretinography waves after treatment with the implant. The presence of the implant, or part of it, was detectable in the vitreous cavity for 4 months. To date, the patient has been monitored for 30 months, and there has been no reactivation of ocular toxoplasmosis.

Conclusion

The slow-release clindamycin implant was safe for intravitreal use in this patient and may have contributed to the long-term control of toxoplasmosis chorioretinitis.

Bilateral ocular toxoplasmosis in a returning traveller: age and route of infection as potential risk factors

We report the case of a 69-year-old man, who presented in the UK with a short history of deteriorating vision and clinical features of bilateral atypical retinochoroiditis, after travelling to South America. Vitreous samples demonstrated Toxoplasma gondii DNA by PCR. Serology tests demonstrated recent acquired Toxoplasma gondii infection with IgM antibodies. He responded well to treatment with trimethoprim-sulfamethoxazole, azithromycin and oral steroids. This case is a reminder of the global importance of Toxoplasma related eye disease, and its uncommon bilateral severe presentation in a returning traveller, where the risk factors were age and the route of infection likely to be a virulent parasite oocyst from vegetables or water rather than undercooked meat or direct contact with cats.

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.

Serological prevalence of toxoplasmosis in pregnant women in Luanda (Angola): Geospatial distribution and its association with socio-demographic and clinical-obstetric determinants

We report a study on toxoplasmosis in pregnant women in Luanda, Angola, determining the seroprevalence, geospatial distribution and its association with socio-economic features, dietary habits and hygiene and health conditions. Anti-Toxoplasma gondii IgG and IgM were quantified in serum samples of women attended at the Lucrecia Paim Maternity Hospital between May 2016 and August 2017. The IgG avidity test and qPCR assay were used for dating the primary infection. Data were collected by questionnaire after written consent, and spatial distribution was assessed through a Kernel Density Function. The potential risk factors associated with Toxoplasma infection were evaluated using bivariate and multivariate binomial logistic regression analysis. Anti-T. gondii antibodies were quantified in 878 pregnant women, and 346 (39.4%) samples were IgG positive, 2 (0.2%) positive for IgM and IgG, and 530 (60.4%) negative for both immunoglobulins. The longitudinal study showed that none of the seronegative women seroconverted during the survey. Regarding other infections, 226 (25.7%) were positive for hepatitis B, while 118 (13.4%) were HIV-positive. The seroprevalence of toxoplasmosis was similar in most municipalities: 43.8% in Cazenga (28 of 64); 42.5% in Viana (88 of 207); 42.3% in Cacuaco (22 of 52); and 41.1% in Luanda ((179 of 435). In contrast, the seroprevalence in municipality of Belas was lower (25.8%; 31 of 120) and bivariate and multivariate analysis has shown a lower risk for toxoplasmosis in this area (OR 0.479, CI: 0.305–0.737; OR 0.471, CI: 0.299–0.728). The multivariate analysis has shown a significant increased risk for toxoplasmosis in women in the last trimester of pregnancy (OR 1.457, CI: 1.011–2.102), suffering spontaneous abortion (OR 1.863, CI: 1.014–3.465) and having pets at home (OR 1.658, CI: 1.212–2.269). Also, women who tested positive for hepatitis B (OR 1.375, CI: 1.008–1.874) and HIV (OR 1.833, CI: 1.233–2.730) had a significant increased risk for T. gondii infection. In conclusion, our study showed that a large number of pregnant women are not immunized for toxoplasmosis and identified the risk factors for this infection in Luanda. It is crucial to establish the diagnosis of primary maternal infection as well as the diagnosis of congenital toxoplasmosis. Our results underlined the need for diagnostic and clinical follow-up of toxoplasmosis, HIV and hepatitis B during pregnancy.

Serosurvey of Anti-Toxoplasma gondii Antibodies in Homeless Persons of São Paulo City, Southeastern Brazil

Seroprevalence of Toxoplasma gondii has been extensively studied in a variety of different human populations. However, no study has focused on homeless populations. Accordingly, the present study aimed to assess the seroprevalence of anti-T. gondii antibodies and the risk factors associated in homeless persons from homeless shelter of São Paulo city, southeastern Brazil. In addition, anti-HIV antibodies and associated risk of T. gondii and HIV coinfection have been evaluated. Anti-T. gondii antibodies were detected by indirect fluorescent antibody test. In addition, anti-HIV levels were tested by chemiluminescence enzyme immunoassay, with positive samples confirmed by rapid immunoblot assay. Overall, IgG anti-T. gondii seropositivity was found in 43/120 (35.8%) homeless persons, with endpoint titers varying from 16 to 1,024. The only two pregnant women tested were negative for IgM by chemiluminescence enzyme immunoassay, with normal parturition and clinically healthy newborns in both cases. There were no statistical differences in the risk factors for anti-T. gondii serology (p > 0.05). Anti-HIV seropositivity was found in 2/120 (1.7%) homeless persons, confirmed as HIV-1. One HIV seropositive individual was also sero-reactive to IgG anti-T. gondii, and both were negative to IgM anti-T. gondii. This is the first study that reports the serosurvey of T. gondii in homeless persons worldwide. Despite the limited sample size available in the present study, our findings have shown that the prevalence of anti-T. gondii antibodies in homeless persons herein was lower than the general population, probably due to homeless diet habit of eating mainly processed food intake. No statistical differences were found regarding risk factors for anti-T. gondii exposure in homeless persons. Future studies should be conducted to fully establish risk factors for anti-T. gondii exposure in homeless persons.

Toxoplasma gondii and multiple sclerosis: a population-based case-control study

According to the hygiene hypothesis, parasites could have a protective role in the development of Multiple Sclerosis (MS). Our aim was to assess the association between presence of anti-Toxoplasma gondii antibodies and MS. MS patients were randomly selected from a population-based incident cohort of MS patients in the city of Catania. Age and sex-matched controls were randomly selected from the general population. Clinical and sociodemographic variables were recorded with a structured questionnaire and a blood sample was taken for serological analysis. Specific T. gondii IgG have been detected with a commercial kit. Adjusted Odds Ratios (ORs) were estimated using unconditional logistic regression. 129 MS subjects (66.7% women with a mean age 44.7 ± 11.0 years) and 287 controls (67.3% women with a mean age 48.1 ± 15.6 years) have been enrolled in the study. Anti-T. gondii antibodies were found in 38 cases (29.5%) and 130 controls (45.4%) giving an adjusted OR of 0.56 (95%CI 0.34–0.93). History of mononucleosis and high educational level were significantly associated with MS (adjOR 2.22 and 1.70 respectively) while an inverse association was found between high educational level and T. gondii seropositivity (adjOR 0.42). Our results further support the protective role of parasitic infections in MS.

Clinical, Socio-economic and Environmental Factors Related with Recurrences in Ocular Toxoplasmosis in Quindío, Colombia

PURPOSE

To identify the sociodemographic, clinical, and environmental factors associated with recurrences in ocular toxoplasmosis (OT).

METHODS

Retrospective analysis of clinical records of patients who consulted in the Health Centre at Universidad del Quindío between 2004 and 2017. Patients with retinochoroiditis due to Toxoplasma gondii infection and follow up >12 months were included. Comparisons were made with a recurrence index adjusted for months of follow up. For the statistical analysis, the Kruskal-Wallis test and analysis of variance (ANOVA) tests were performed in Epi Info 7.2 and SPSS 14.0. A statistical significance is shown if p ≤ 0.05.

RESULTS

A total of 58 patients were included, with median age of 28 years (range 1-61) and 55.1% were women. The median of recurrences was 1.4 (range 0.6-16.6). High recurrence index was present in 43.1% of the patients. A higher size of lesions was observed in low socioeconomic groups (p = .016) and patients with congenital infection had more bilateral compromise (p = .002). Intake of boiled water was related to a lower recurrence index (p = .04).

CONCLUSIONS

Low socioeconomic level was associated with bigger lesions and congenital infection was related with higher frequency of bilateral OT. Finally, intake of boiled water is related to a lower recurrence index of OT.

Implications of TORCH Diseases in Retinal Development-Special Focus on Congenital Toxoplasmosis

There are certain critical periods during pregnancy when the fetus is at high risk for exposure to teratogens. Some microorganisms, including Toxoplasma gondii, are known to exhibit teratogenic effects, interfering with fetal development and causing irreversible disturbances. T. gondii is an obligate intracellular parasite and the etiological agent of Toxoplasmosis, a zoonosis that affects one third of the world's population. Although congenital infection can cause severe fetal damage, the injury extension depends on the gestational period of infection, among other factors, like parasite genotype and host immunity. This parasite invades the Central Nervous System (CNS), forming tissue cysts, and can interfere with neurodevelopment, leading to frequent neurological abnormalities associated with T. gondii infection. Therefore, T. gondii is included in the TORCH complex of infectious diseases that may lead to neurological malformations (Toxoplasmosis, Others, Rubella, Cytomegalovirus, and Herpes). The retina is part of CNS, as it is derived from the diencephalon. Except for astrocytes and microglia, retinal cells originate from multipotent neural progenitors. After cell cycle exit, cells migrate to specific layers, undergo morphological and neurochemical differentiation, form synapses and establish their circuits. The retina is organized in nuclear layers intercalated by plexus, responsible for translating and preprocessing light stimuli and for sending this information to the brain visual nuclei for image perception. Ocular toxoplasmosis (OT) is a very debilitating condition and may present high severity in areas in which virulent strains are found. However, little is known about the effect of congenital infection on the biology of retinal progenitors/ immature cells and how this infection may affect the development of this tissue. In this context, this study reviews the effects that congenital infections may cause to the developing retina and the cellular and molecular aspects of these diseases, with special focus on congenital OT.

Catastrophic consequences: can the feline parasite Toxoplasma gondii prompt the purrfect neuroinflammatory storm following traumatic brain injury?

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality worldwide; however, treatment development is hindered by the heterogenous nature of TBI presentation and pathophysiology. In particular, the degree of neuroinflammation after TBI varies between individuals and may be modified by other factors such as infection. Toxoplasma gondii, a parasite that infects approximately one-third of the world’s population, has a tropism for brain tissue and can persist as a life-long infection. Importantly, there is notable overlap in the pathophysiology between TBI and T. gondii infection, including neuroinflammation. This paper will review current understandings of the clinical problems, pathophysiological mechanisms, and functional outcomes of TBI and T. gondii, before considering the potential synergy between the two conditions. In particular, the discussion will focus on neuroinflammatory processes such as microglial activation, inflammatory cytokines, and peripheral immune cell recruitment that occur during T. gondii infection and after TBI. We will present the notion that these overlapping pathologies in TBI individuals with a chronic T. gondii infection have the strong potential to exacerbate neuroinflammation and related brain damage, leading to amplified functional deficits. The impact of chronic T. gondii infection on TBI should therefore be investigated in both preclinical and clinical studies as the possible interplay could influence treatment strategies.

A decreasing trend in toxoplasma gondii seroprevalence among pregnant women in Romania - results of a large scale study

Toxoplasmosis is a zoonotic infection caused by the obligate intracellular apicomplexan parasite Toxoplasma gondii (T. gondii). T. gondii infection is a cause of congenital infection worldwide. Primary infection or the reactivation of latent infection during pregnancy may lead to fetal infection and to congenital toxoplasmosis syndrome. Seropositive pregnant women are generally protected from maternal-fetal transmission of T. gondii, although exceptions exist. The aim of our study was to analyze the dynamics of T. gondii seroprevalence during a 10-year period and to correlate it with age and demographic features of pregnant women. We tested 6,889 pregnant women in Timisoara, Romania, for IgG-anti-T. gondii antibodies, in two successive periods: i) 2008-2010 (group 1: 1,457 participants); and ii) 2015-2018 (group 2: 5,432 participants). For each participant, data on age and area of residence were collected. Our results showed that in the Western Region of Romania T. gondii seroprevalence in pregnant women declined from 43.79 to 38.81% in the last ten years. This trend was observed in both urban (40.53 vs. 34.85%) and rural areas (52.22 vs. 46.22%). A higher seroprevalence rate was found in rural than in urban areas. In addition, we found an increasing tendency of seroprevalence related to the age of pregnant women.

Spatial serosurvey of anti-Toxoplasma gondii antibodies in individuals with animal hoarding disorder and their dogs in Southern Brazil

Despite vulnerability and unsanitary conditions of animal hoarding may predispose environmental contamination and spread of vectors and pathogens, no study to date has focused on their impact on public health and zoonotic diseases. Accordingly, this study aimed to assess the seroprevalence of anti-Toxoplasma gondii antibodies and associated factors in individuals with animal hoarding disorder (AHD) and their dogs in Curitiba, Southern Brazil. Blood samples were obtained from 264 dogs (21 households) and 19 individuals with AHD (11 households). Their blood was tested by indirect fluorescent antibody test (IFAT). Overall, anti-Toxoplasma gondii seropositivity was found in 21/264 dogs (7.95%; 95% CI: 4.69–11.22) with titers ranging from 16 to 4096, and in 7/19 individuals with AHD (36.84%; CI: 15.15–58.53) with titers ranging from 16 to 64. Serological analysis for anti-T. gondii antibodies were considered positive in at least one individual or dog in 9/11 (81.82%; 95% CI: 59.03–100.00) cases that were thoroughly assessed. Surprisingly, the seropositivity of individuals with AHD and their dogs was among the lowest reportedly observed in human and dog populations of Brazil. There was no significant association between positive owners and positive dogs or the presence of cats in the household. Regard epidemiological variables, a significant association was found between dog’s seropositivity and the type of dog food. To the authors’ knowledge, the present study represents the first investigation of T. gondii seroprevalence in individuals with hoarding disorder and their dogs. In conclusion, despite low sanitary conditions, anti-Toxoplasma gondii antibodies frequency in individuals with AHD and their dogs are lower than the general population likely due to low protozoan load in such isolated households.

Cat-dependent diseases cost Australia AU$6 billion per year through impacts on human health and livestock production

Abstract ContextCats are the definitive or primary host for pathogens that cause diseases in people and livestock. These cat-dependent diseases would not occur in Australia if cats had not been introduced, and their ongoing persistence depends on contacts with cats. Toxoplasma gondii is a protozoan parasite that cycles between cats and any other warm-blooded animals. People infected by T. gondii may appear asymptomatic, or have a mild illness, or experience severe, potentially lethal symptoms; the parasite may also affect behaviour and mental health. T. gondii is also a major contributor to spontaneous abortion in sheep and goats. Two species of Sarcocystis, another genus of protozoan parasite, cycle through cats and sheep, causing macroscopic cysts to form in sheep tissues that reduce meat saleability. Toxocara cati, the cat roundworm, causes minor illnesses in humans and livestock, and the bacterium Bartonella henselae causes cat scratch disease, an infection that can be contracted by people when scratched or bitten by cats carrying the pathogen. AimsWe estimated the economic costs of cat-dependent pathogens in Australia. MethodsWe collated national and global data on infection rates, health and production consequences. Key resultsWe estimated the costs of two cat-dependent diseases (toxoplasmosis, cat scratch disease) in people at AU$6.06 billion (plausible range AU$2.11–10.7 billion) annually, and the costs to livestock production from toxoplasmosis and sarcocystosis at AU$11.7 million (plausible range AU$7.67–18.3 million). Most of the human health costs are due to the associations between T. gondii and higher rates of traffic accidents and mental illness in people. The causality behind these associations remains uncertain, so those costs may be overestimated. Conversely, our estimates are incomplete, infections and illness are under-reported or misdiagnosed, and our understanding of disease outcomes is still imperfect, all of which make our costs underestimated. ConclusionsOur analysis suggests that substantial benefits to public health and livestock production could be realised by reducing exposure to cats and breaking parasite transmission cycles. ImplicationsReducing feral cat populations in farming and urban areas, reducing the pet cat population and increasing rates of pet cat containment could help reduce the burden of cat-dependent diseases to people and livestock.

Driving us mad: the association of Toxoplasma gondii with suicide attempts and traffic accidents - a systematic review and meta-analysis

Unnatural causes of death due to traffic accidents (TA) and suicide attempts (SA) constitute a major burden on global health, which remained stable in the last decade despite widespread efforts of prevention. Recently, latent infection with Toxoplasma gondii (T. gondii) has been suggested to be a biological risk factor for both TA and SA. Therefore, a systematic search concerning the relationship of T. gondii infection with TA and/or SA according to PRISMA guidelines in Medline, Pubmed and PsychInfo was conducted collecting papers up to 11 February 2019 (PROSPERO #CRD42018090206). The random-effect model was applied and sensitivity analyses were subsequently performed. Lastly, the population attributable fraction (PAF) was calculated. We found a significant association for antibodies against T. gondii with TA [odds ratio (OR) = 1.69; 95% confidence interval (CI) 1.20-2.38, p = 0.003] and SA (OR = 1.39; 95% CI 1.10-1.76, p = 0006). Indication of publication bias was found for TA, but statistical adjustment for this bias did not change the OR. Heterogeneity between studies on SA was partly explained by type of control population used (ORhealthy controls = 1.9, p &lt; 0.001 v. ORpsychiatric controls = 1.06, p = 0.87) and whether subjects with schizophrenia only were analysed (ORschizophrenia = 0.87, p = 0.62 v. ORvarious = 1.8, p &lt; 0.001). The association was significantly stronger with higher antibody titres in TA and in studies that did not focus on schizophrenia subjects concerning SA. PAF of a T. gondii infection was 17% for TA and 10% for SA. This indicates that preventing T. gondii infection may play a role in the prevention of TA or SA, although uncertainty remains whether infection and outcome are truly causally related.