Mathematical modeling of contact tracing and stability analysis to inform its impact on disease outbreaks; an application to COVID-19.

We develop a mathematical model to investigate the effect of contact tracing on containing epidemic outbreaks and slowing down the spread of transmissible diseases. We propose a discrete-time epidemic model structured by disease-age which includes general features of contact tracing. The model is fitted to data reported for the early spread of COVID-19 in South Korea, Brazil, and Venezuela. The calibrated values for the contact tracing parameters reflect the order pattern observed in its performance intensity within the three countries. Using the fitted values, we estimate the effective reproduction number Re and investigate its responses to varied control scenarios of contact tracing. Alongside the positivity of solutions, and a stability analysis of the disease-free equilibrium are provided.

Quality of life in men after total cystoprostatectomy: Perceptions of Tunisian patients.

INTRODUCTION: Total cystoprostatectomy (TCP) causes many changes in the postoperative quality of life leading to psychological, physical, social and sexual repercussions that are difficult to manage. This study aims to describe the postoperative quality of life of elderly Tunisian men who had a TCP as a result of a bladder cancer. METHODS: A descriptive quantitative study was conducted with 40 cystoprostatectomized men. Data collection tools were the Stoma-quality of life (QOL) questionnaire of Prieto, Thorsen, and Juul (2005) translated and validated to the Arabic language, and the Arabic version of the International Index of Erectile Function (IIEF5) questionnaire validated by Shamloul, Ghanem and Abou-Zeid (2004). RESULTS: 77.5% of participants had a very low quality-of-life score. All dimensions of quality of life-body image, physical, psychological, family and social life, and sexuality-were affected. In addition, all participants have suffered from severe sexual impotence after surgery. CONCLUSION: Counselling pre and postoperatively needed to facilitate the postoperative transition and ensure a better quality of life related to the health of men with bladder cancer.

Meningeal Hemangiopericytomas and Meningomas: a Comparative Immunohistochemical and Genetic Study.

BACKGROUND: The meningeal hemangiopericytoma (MHPC) is a vascular tumor arising from pericytes. Most intracranial MHPCs resemble meningiomas (MNGs) in their clinical presentation and histological features and may therefore be misdiagnosed, despite important differences in prognosis. MATERIALS AND METHODS: We report 8 cases of MHPC and 5 cases of MNG collected from 2007 to 2011 from the Neuro-Surgery and Histopathology departments. All 13 samples were re reviewed by two independent pathologists and investigated by immunohistochemistry (IHC) using mesenchymal, epithelial and neuro-glial markers. Additionally, we screened all tumors for a large panel of chromosomal alterations using multiplex ligation probe amplification (MLPA). Presence of the NAB2-STAT6 fusion gene was inferred by immunohistochemical staining for STAT6. RESULTS: Compared with MNG, MHPCs showed strong VIM (100% of cases), CD99 (62%), bcl-2 (87%), and p16 (75%) staining but only focal positivity with EMA (33%) and NSE (37%). The p21 antibody was positive in 62% of MHPC and less than 1% in all MNGs. MLPA data did not distinguish HPC from MNG, with PTEN loss and ERBB2 gain found in both. By contrast, STAT6 nuclear staining was observed in 3 MHPC cases and was absent from MNG. CONCLUSIONS: MNG and MHPC comprise a spectrum of tumors that cannot be easily differentiated based on histopathology. The presence of STAT6 nuclear positivity may however be a useful diagnostic marker.

Glioma epidemiology in the central Tunisian population: 1993-2012.

BACKGROUND: Glioma is a heterogeneous central nervous system (CNS) tumor group that encompasses different histological subtypes with high variability in prognosis. The lesions account for almost 80% of primary malignant brain tumors. The aim of this study is to extend our understanding of the glioma epidemiology in the central Tunisian region. MATERIALS AND METHODS: We analyzed 393 gliomas recorded in cancer registry of central Tunisia from 1993 to 2012. Crude incidence rates (CR) and world age-standardized rates (ASR) were estimated using annual population data size and age structure. Statistic correlations were established using Chi-square and Kaplan-Meier test. RESULTS: Tunisian glioma patients were identified with a mean age at diagnosis of 48 years and 1.5 sex ratio (male/female). During the 19 years period of study the highest incidence value was observed in male group between 1998 and 2002 (CR: 0.28, ASR: 0.3). Incidence results underline increasing high grade glioma occurring in the adulthood in the last period (2007-2012). Median survival was 27 months, with 1-, 2- and 5-year survival rates of 42%, 30% and 26%, respectively. Survival was greater in patients with younger age, lower tumor grade, infratentrial tumor location and undergoing a palliative treatment. CONCLUSIONS: This central Tunisia gliomas registry study provides important information that could improve glioma management and healthcare practice.

Acute circulatory deficiency due to endocrinal tumoral manipulation: the pinealoblastoma.

We rapport the case of a patient presenting intra-abdominal metastasis of a pinealoblastoma, via a ventriculo-peritoneal shunt, confirmed by an anatomo-pathologic exam. The patient presented an acute hydrocephalus secondary to DVP dysfunction. The surgical manipulation of this metastasis had caused an acute circulatory deficiency due to massive serotonin release. In this case we analyze pineal gland physiology and serotonin effect on different systems.

Salmonella typhimurium epidural empyema in an HIV-infected patient.

Salmonella focal intracranial infections are reported rarely. They tend to occur in immunocompromised patients. We present here a case of Salmonella typhimurium epidural empyema, with osteomyelitis of the adjacent frontal bone, in a 37-year-old human immunodeficiency virus positive man who presented with a three-day history of headache, fever, and sweats. He was treated successfully with antibiotics and surgical drainage.