Risks of COVID-19 transmission in blood and serum during surgery A prospective cross-sectional study from a single dedicated COVID-19 center.

The present pandemic caused by the SARS COV-2 coronavirus is still ongoing, although it is registered a slowdown in the spread for new cases. The main environmental route of transmission of SARS-CoV-2 is through droplets and fomites or surfaces, but there is a potential risk of virus spread also in smaller aerosols during various medical procedures causing airborne transmission. To date, no information is available on the risk of contagion from the peritoneal fluid with which surgeons can come into contact during the abdominal surgery on COVID-19 patients. We have investigated the presence of SARS-CoV-2 RNA in the peritoneal cavity of patients affected by COVID-19, intraoperatively and postoperatively. KEY WORDS: Covid-19, Laparotomy, Surgery.

Large bowel perforation secondary to CMV colitis: an unusual primary presentation of HIV infection.

We report a case of HIV-associated Cytomegalovirus colitis complicated by large bowel perforation. A 62-year-old man of same-sex relationship was not known to have HIV, but a diagnosis of inflammatory bowel disease was made early in his admission, with steroid treatment initiated. He was later confirmed to be HIV positive, and found to have multiple microperforations of the bowel necessitating ileocecectomy and Hartmann's procedures.

Recurrent lower gastrointestinal bleeding secondary to cytomegalovirus-associated colonic ulcer in a non human immunodeficiency virus infected patient: timely diagnosis and treatment averted surgery.

Mr C, a 68-year-old Chinese male with diabetes mellitus, previous stroke and ischaemic cardiomyopathy on clopidogrel, presented with haematochezia. Colonoscopy showed a sigmoid ulcer, which was treated endoscopically. Histology of the biopsy from the ulcer revealed non-specific changes. However, he presented with recurrent bleeding from this non-healing sigmoid ulcer. A review of the histologic specimen revealed CMV intranuclear inclusion bodies. He was treated with intravenous ganciclovir, with no further hematochezia.

HIV-1 pathogenesis differs in rectosigmoid and tonsillar tissues infected ex vivo with CCR5- and CXCR4-tropic HIV-1.

Gut-associated lymphoid tissue (GALT) has been identified as the primary target of HIV-1 infection. To investigate why GALT is especially vulnerable to HIV-1, and to determine whether the selective transmission of CCR5-using viral variants (R5) in vivo is the result of a greater susceptibility of GALT to this viral variant, we performed comparative studies of CXCR4-using (X4) and R5 HIV-1 infections of human lymphoid (tonsillar) and rectosigmoid tissues ex vivo under controlled laboratory conditions. We found that the relative level of R5 replication in rectosigmoid tissue is much greater than in tonsillar tissue. This difference is associated with the expression of the CCR5 co-receptor on approximately 70% of CD4 T cells in rectosigmoid tissue, whereas in tonsillar tissue it is expressed on fewer than 15% of CD4 T cells. Furthermore, tonsillar tissue responds to X4 HIV-1 infection by upregulating the secretion of CC-chemokines, providing a potential CCR5 blockade and further resistance to R5 infection, whereas gut tissue failed to increase such innate immune responses. Our results show that rectosigmoid tissue is more prone than tonsillar lymphoid tissue to R5 HIV-1 infection, primarily because of the high prevalence and availability of R5 cell targets and reduced chemokine blockade. The majority of CD4 T cells express CXCR4, however, and X4 HIV-1 readily replicates in both tissues, suggesting that although the differential expression of co-receptors contributes to the GALT vulnerability to R5 HIV-1, it alone cannot account for the selective R5 infection of the rectal mucosa in vivo.