Investigation of US Cyclospora cayetanensis outbreaks in 2019 and evaluation of an improved Cyclospora genotyping system against 2019 cyclosporiasis outbreak clusters.

Cyclosporiasis is an illness characterised by watery diarrhoea caused by the food-borne parasite Cyclospora cayetanensis. The increase in annual US cyclosporiasis cases led public health agencies to develop genotyping tools that aid outbreak investigations. A team at the Centers for Disease Control and Prevention (CDC) developed a system based on deep amplicon sequencing and machine learning, for detecting genetically-related clusters of cyclosporiasis to aid epidemiologic investigations. An evaluation of this system during 2018 supported its robustness, indicating that it possessed sufficient utility to warrant further evaluation. However, the earliest version of CDC's system had some limitations from a bioinformatics standpoint. Namely, reliance on proprietary software, the inability to detect novel haplotypes and absence of a strategy to select an appropriate number of discrete genetic clusters would limit the system's future deployment potential. We recently introduced several improvements that address these limitations and the aim of this study was to reassess the system's performance to ensure that the changes introduced had no observable negative impacts. Comparison of epidemiologically-defined cyclosporiasis clusters from 2019 to analogous genetic clusters detected using CDC's improved system reaffirmed its excellent sensitivity (90%) and specificity (99%), and confirmed its high discriminatory power. This C. cayetanensis genotyping system is robust and with ongoing improvement will form the basis of a US-wide C. cayetanensis genotyping network for clinical specimens

Tumors of the Chest Wall

Primary tumors of the chest wall are uncommon. Chest wall tumors, whether malignant or benign,are classified as primary or secondary (metastatic).The most common benign tumors are osteochondromas and chondromas. The most common malignant chest wall tumors are sarcomas. Most primary tumors originate in the bones or muscles of the chest wall, though they can also arise from nerves and vessels. Less than half of malignant chest wall tumors are primary. Secondary tumors originate elsewhere in the body and spread (metastasize) to the chest wall. The most frequent secondary tumors of the chest wall spread from primary breast and lung cancer. In fact, they can either locally extend to the chest wall, or metastasize to it. Furthermore, other tumors that are not unfrequently spread to the pleura include those originating from ovary, kidney, uterus, head and neck, and testis. Therefore, almost all secondary tumors are malignant. Most chest wall tumors found in children are primary, while most found in adults are secondary . It is often difficult to make an accurate presurgical diagnosis and differentiate benign from malignant tumors. Most patients with primary chest wall tumor receive surgical biopsy or radical surgical resection