Novel paradigm enables accurate monthly gestational screening to prevent congenital toxoplasmosis and more

Background

Congenital toxoplasmosis is a treatable, preventable disease, but untreated causes death, prematurity, loss of sight, cognition and motor function, and substantial costs worldwide.

Methods/Findings

In our ongoing USA feasibility/efficacy clinical trial, data collated with other ongoing and earlier published results proved high performance of an Immunochromatographic-test(ICT) that enables accurate, rapid diagnosis/treatment, establishing new paradigms for care. Overall results from patient blood and/or serum samples tested with ICT compared with gold-standard-predicate-test results found ICT performance for 4606 sera/1876 blood, 99.3%/97.5% sensitive and 98.9%/99.7% specific. However, in the clinical trial the FDA-cleared-predicate test initially caused practical, costly problems due to false-positive-IgM results. For 58 persons, 3/43 seronegative and 2/15 chronically infected persons had false positive IgM predicate tests. This caused substantial anxiety, concerns, and required costly, delayed confirmation in reference centers. Absence of false positive ICT results contributes to solutions: Lyon and Paris France and USA Reference laboratories frequently receive sera with erroneously positive local laboratory IgM results impeding patient care. Therefore, thirty-two such sera referred to Lyon's Reference laboratory were ICT-tested. We collated these with other earlier/ongoing results: 132 of 137 USA or French persons had false positive local laboratory IgM results identified correctly as negative by ICT. Five false positive ICT results in Tunisia and Marseille, France, emphasize need to confirm positive ICT results with Sabin-Feldman-Dye-test or western blot. Separate studies demonstrated high performance in detecting acute infections, meeting FDA, CLIA, WHO ASSURED, CEMark criteria and patient and physician satisfaction with monthly-gestational-ICT-screening.

Conclusions/Significance

This novel paradigm using ICT identifies likely false positives or raises suspicion that a result is truly positive, rapidly needing prompt follow up and treatment. Thus, ICT enables well-accepted gestational screening programs that facilitate rapid treatment saving lives, sight, cognition and motor function. This reduces anxiety, delays, work, and cost at point-of-care and clinical laboratories.

Author’s Summary

Toxoplasmosis is a major health burden for developed and developing countries, causing damage to eyes and brain, loss of life and substantial societal costs. Prompt diagnosis in gestational screening programs enables treatment, thereby relieving suffering, and leading to > 14-fold cost savings for care. Herein, we demonstrate that using an ICT that meets WHO ASSURED-criteria identifying persons with/without antibody to Toxoplasma gondii in sera and whole blood with high sensitivity and specificity, is feasible to use in USA clinical practice. We find this new approach can help to obviate the problem of detection of false positive anti- T.gondii IgM results for those without IgG antibodies to T.gondii when this occurs in present, standard of care, predicate USA FDA cleared available assays. Thus, this accurate test facilitates gestational screening programs and a global initiative to diagnose and thereby prevent and treat T.gondii infection. This minimizes likelihood of false positives (IgG and/or IgM) while maintaining maximum sensitivity. When isolated IgM antibodies are detected, it is necessary to confirm and when indicated continue follow up testing in ∼2 weeks to establish seroconversion. Presence of a positive ICT makes it likely that IgM is truly positive and a negative ICT makes it likely that IgM will be a false positive without infection. These results create a new, enthusiastically-accepted, precise paradigm for rapid diagnosis and validation of results with a second-line test. This helps eliminate alarm and anxiety about false-positive results, while expediting needed treatment for true positive results and providing back up distinguishing false positive tests.

Validation of the Nigerian Breast Cancer Study Model for Predicting Individual Breast Cancer Risk in Cameroon and Uganda

BACKGROUND

The Nigerian Breast Cancer Study (NBCS) model is a new risk assessment tool developed for predicting risk of invasive breast cancer in Nigeria. Its applicability outside of Nigeria remains uncertain as it has not been validated in other sub-Saharan Africa populations.

METHODS

We conducted a case-control study among women with breast cancer and controls ascertained in Cameroon and Uganda from 2011 to 2016. Structured questionnaire interviews were performed to collect risk factor characteristics. The NBCS model, the Gail model, the Gail model for Black population, and the Black Women's Health Study model were applied to the Cameroon and Uganda samples separately. Nigerian as well as local incidence rates were incorporated into the models. Receiver-Operating Characteristic analyses were performed to indicate discriminating capacity.

RESULTS

The study included 550 cases (mean age 46.8 ± 11.9) and 509 controls (mean age 46.3 ± 11.7). Compared with the other three models, the NBCS model performed best in both countries. The discriminating accuracy of the NBCS model in Cameroon (age-adjusted C-index = 0.602; 95% CI, 0.542-0.661) was better than in Uganda (age-adjusted C-index = 0.531; 95% CI, 0.459-0.603).

CONCLUSIONS

These findings demonstrate the potential clinical utility of the NBCS model for risk assessment in Cameroon. All currently available models performed poorly in Uganda, which suggests that the NBCS model may need further calibration before use in other regions of Africa.

IMPACT

Differences in risk profiles across the African diaspora underscores the need for larger studies and may require development of region-specific risk assessment tools for breast cancer.

Building Programs to Eradicate Toxoplasmosis Part III: Epidemiology and Risk Factors

Purpose of Review

Review comprehensive data on rates of toxoplasmosis in Panama and Colombia.

Recent Findings

Samples and data sets from Panama and Colombia, that facilitated estimates regarding seroprevalence of antibodies to Toxoplasma and risk factors, were reviewed.

Summary

Screening maps, seroprevalence maps, and risk factor mathematical models were devised based on these data. Studies in Ciudad de Panamá estimated seroprevalence at between 22 and 44%. Consistent relationships were found between higher prevalence rates and factors such as poverty and proximity to water sources. Prenatal screening rates for anti-Toxoplasma antibodies were variable, despite existence of a screening law. Heat maps showed a correlation between proximity to bodies of water and overall Toxoplasma seroprevalence. Spatial epidemiological maps and mathematical models identify specific regions that could most benefit from comprehensive, preventive healthcare campaigns related to congenital toxoplasmosis and Toxoplasma infection.

Building Programs to Eradicate Toxoplasmosis Part II: Education

Purpose of Review

Review work to create and evaluate educational materials that could serve as a primary prevention strategy to help both providers and patients in Panama, Colombia, and the USA reduce disease burden of Toxoplasma infections.

Recent Findings

Educational programs had not been evaluated for efficacy in Panama, USA, or Colombia.

Summary

Educational programs for high school students, pregnant women, medical students and professionals, scientists, and lay personnel were created. In most settings, short-term effects were evaluated. In Panama, Colombia, and USA, all materials showed short-term utility in transmitting information to learners. These educational materials can serve as a component of larger public health programs to lower disease burden from congenital toxoplasmosis. Future priorities include conducting robust longitudinal studies of whether education correlates with reduced adverse disease outcomes, modifying educational materials as new information regarding region-specific risk factors is discovered, and ensuring materials are widely accessible.

Association of morningness-eveningness with psychiatric symptoms among pregnant women

In the present study, we examined associations between circadian preference and psychiatric symptoms among 1,796 pregnant women from Lima, Peru. One quarter were classified as evening types. Compared to morning types, evening type pregnant women had increased odds of generalized anxiety (OR = 1.44; 95%CI: 1.12-1.86) and posttraumatic stress disorder (OR = 1.38; 95%CI: 1.07-1.78). Although there was a positive trend, evening chronotype was not significantly associated with elevated odds of depression (OR = 1.23; 95%CI: 0.94-1.61). Future studies are warranted to help understand the underlying behavioral, biological, and genetic pathways of these associations. Assessing circadian preference may help clinicians identify pregnant women at risk for psychiatric symptoms.

Abstract 879: Validation of the Nigerian Breast Cancer Study model for predicting individual breast cancer risk in Cameroon and Uganda

Background: Women of African ancestry across the diaspora have low risk of developing breast cancer compared to women of European ancestry. However, they suffer the highest mortality rates because of the disproportionate burden of young onset aggressive hormone receptor negative breast cancer. To implement strategies for early detection and prevention, it is critically important to develop better risk assessment tools. The Nigerian Breast Cancer Study (NBCS) model is a new risk assessment tool developed for the individual estimation of absolute risk of invasive breast cancer in Nigeria. Its applicability outside of Nigeria remains uncertain as it has not been validated in other Sub-Sahara African (SSA) populations.

Methods: We conducted a case-control study among women with breast cancer and controls ascertained in Cameroon and Uganda from 2011 to 2016. Structured questionnaire interviews were performed to collect demographic and reproductive characteristics. The NBCS model, the Gail model for white population, the Gail model for Black population (CARE), and the Black Women's Health Study (BWHS) model were applied to the Cameroon and Uganda samples separately. Local incidence rates were incorporated into the NBCS model for the Uganda analysis. Receiver-Operating Characteristic (ROC) analyses were performed and the area under ROC curve was used to indicate discriminating capacity.

Results: The cohort included 549 cases (mean age 47 ± 11.94) and 509 Controls (mean age 46 ± 11.68). Compared to the other three models, the NBCS model performed best in both countries. The discriminating accuracy of the NBCS model in Cameroon (age-adjusted C-index = 0.599, 95% CI 0.540-0.658) was significantly better than in Uganda (age-adjusted C-index = 0.511, 95% CI, 0.437-0.585). In Cameroon, the BWHS model had slightly lower distinguishing ability (age-adjusted C-index = 0.588, 95% CI, 0.528-0.647) and gave lower risk estimates in cases than the NBCS model. The Gail and CARE models performed poorly in both countries.

Conclusions: These findings demonstrate the potential clinical utility of the NBCS model for risk assessment in Cameroon. All currently available models performed poorly in Uganda, which suggests that the NBCS model may need further calibration before use in other regions of Africa. Differences in risk profiles across the African diaspora underscores the need for larger studies and may require development of country or region-specific risk assessment tools for breast cancer.

Citation Format: Kevin Ashi, Paul Ndom, Antony Gakwaya, Timothy Makumbi, Olufunmilayo I. Olopade, Dezheng Huo. Validation of the Nigerian Breast Cancer Study model for predicting individual breast cancer risk in Cameroon and Uganda [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 879.