Rapid genomic surveillance of SARS-CoV-2 in a dense urban community of Kathmandu Valley using sewage samples.

Understanding disease burden and transmission dynamics in resource-limited, low-income countries like Nepal are often challenging due to inadequate surveillance systems. These issues are exacerbated by limited access to diagnostic and research facilities throughout the country. Nepal has one of the highest COVID-19 case rates (915 cases per 100,000 people) in South Asia, with densely-populated Kathmandu experiencing the highest number of cases. Swiftly identifying case clusters (hotspots) and introducing effective intervention programs is crucial to mounting an effective containment strategy. The rapid identification of circulating SARS-CoV-2 variants can also provide important information on viral evolution and epidemiology. Genomic-based environmental surveillance can help in the early detection of outbreaks before clinical cases are recognized and identify viral micro-diversity that can be used for designing real-time risk-based interventions. This research aimed to develop a genomic-based environmental surveillance system by detecting and characterizing SARS-CoV-2 in sewage samples of Kathmandu using portable next-generation DNA sequencing devices. Out of 22 sites in the Kathmandu Valley from June to August 2020, sewage samples from 16 (80%) sites had detectable SARS-CoV-2. A heatmap was created to visualize the presence of SARS-CoV-2 infection in the community based on viral load intensity and corresponding geospatial data. Further, 47 mutations were observed in the SARS-CoV-2 genome. Some detected mutations (n = 9, 22%) were novel at the time of data analysis and yet to be reported in the global database, with one indicating a frameshift deletion in the spike gene. SNP analysis revealed possibility of assessing circulating major/minor variant diversity on environmental samples based on key mutations. Our study demonstrated the feasibility of rapidly obtaining vital information on community transmission and disease dynamics of SARS-CoV-2 using genomic-based environmental surveillance.

Vulnerabilities for Exposure to Emerging Infectious Disease at Urban Settlements in Nepal.

In Nepal, rapid urbanization and rural-to-urban migration especially due to internal civil conflict have catalyzed the development of temporary settlements, often along rivers on undeveloped land. This study conducted surveillance for viruses in small mammals and assessed potential risks for virus transmission to people in urban settlements along rivers in Kathmandu, Nepal. We collected samples from 411 small mammals (100 rodents and 311 shrews) at four riverside settlement sites and detected six viruses from four virus families including Thottapalayam virus; a strain of murine coronavirus; two new paramyxoviruses; and two new rhabdoviruses. Additionally, we conducted surveys of 264 residents to characterize animal-human contact. Forty-eight percent of individuals reported contact with wildlife, primarily with rodents and shrews (91%). Our findings confirm that rodents and shrews should be considered a health threat for residents of temporary settlements, and that assessment of disease transmission risk coupled with targeted surveillance for emerging pathogens could lead to improved disease control and health security for urban populations. Additionally, interventions focused on disease prevention should consider the unique urban ecology and social dynamics in temporary settlements, along with the importance of community engagement for identifying solutions that address specific multi-dimensional challenges that life on the urban river margins presents.

Correction: Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal.

[This corrects the article DOI: 10.1371/journal.pone.0133035.].

Catamenial Pneumothorax, a Commonly Misdiagnosed Thoracic Condition: Multicentre Experience and Audit of a Small Case Series With Review of the Literature.

BACKGROUND: Catamenial pneumothorax (CP) is an unusual condition affecting premenopausal women and commonly misdiagnosed as simple pneumothorax. It is characterised by its recurrence between the day before and within 72 hours after the onset of menstruation. It has been associated with thoracic endometriosis but the aetiology is not well understood and there is no unified agreement for its optimal management. The aim of this study is to determine the incidence of CP in surgical patients and the results of their treatment. METHODS: Females between the ages of 30 to 50 years with a diagnosis of pneumothorax, admitted for surgery over a 10-year period in four different hospitals were retrospectively reviewed for evidence of CP. An audit of surgical and medical management of the patients with CP and their short to midterm outcomes was performed in addition to a systemic review of the literature on CP. RESULT: A total of 120 premenopausal female patients with a diagnosis of pneumothorax were admitted for Video Assisted Thoracoscopic (VAT) surgery and five women (4.1%) with a mean age of 42.6 years were diagnosed to have CP through surgical and histological findings. The first case was diagnosed 5 years ago and the last three within recent 12 months after the changes in surgical practices of inspecting diaphragmatic surface in suspected cases of CP. Four patients underwent diaphragmatic plication and one patient had a pleural biopsy. All patients underwent talc pleurodesis and hormone therapy in the postoperative period. Short to midterm (mean follow-up period of 25.2 months) results of the patients with CP were encouraging. CONCLUSIONS: It is possible that many of the cohort of premenopausal female patients presenting with recurrent pneumothorax are misdiagnosed as spontaneous pneumothorax (SP) because routine inspection of the diaphragmatic surface is not often performed. A thorough menstrual history and its temporal relation to pneumothorax onset should be assessed on every woman presenting with recurrent pneumothorax and intraoperative exploration of diaphragmatic surface should be performed in the patients with high suspicion of CP as the patients diagnosed with CP have a good outcome with surgery and hormone therapy.

Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal.

Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO). Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal.

E-cadherin expression: a diagnostic utility for differentiating breast carcinomas with ductal and lobular morphologies.

OBJECTIVES: The objective of this study was to evaluate the diagnostic utility of the E-Cadherin (EC) expression in differentiating between an infiltrating ductal carcinoma (IDC) and an infiltrating lobular carcinoma (ILC), the two most common forms of invasive breast carcinomas. METHODS: The authors evaluated the E-Cadherin expression by doing immunohistochemistical studies of all the cases of invasive lobular carcinomas (ILC) which were diagnosed in the pathology laboratory during a 3 year period and they compared the expression of E-Cadherin in an equal number of invasive ductal carcinomas (IDC) of the breast. RESULTS: A moderate to strong inter-membranous E-Cadherin expression on immunohistochemistry was seen in all the cases of IDC, while only 1 case of ILC showed a moderate E-Cadherin expression. Hence, the E-cadherin expression can be reliably used as a marker to differentiate IDC and ILC. However, an aberrant cytoplasmic expression of E-Cadherin may be seen in some cases of ILC, which should be interpreted with caution.

Partial replacement of tricuspid valve using cryopreserved homograft.

BACKGROUND: The optimal choice of prosthesis for tricuspid valve (TV) replacement is yet to be determined. Partial replacement of the TV using a homograft atrioventricular valve might offer resistance to infection, good durability, and excellent functionality, in addition to avoiding prosthesis-related morbidity. METHODS: We present 14 patients who underwent replacement of the TV using a homograft between 1997 and 2008. The mean age at operation was 32 years, including 5 patients younger than the age of 10. All patients preoperatively showed severe TV regurgitation as a result of active infective endocarditis in 5 patients, Ebstein anomaly in 4 patients, other cardiac anomalies in 4 patients, and rheumatic valvular disease in 1 patient. The TV homograft was used in 13 patients, and mitral homograft was used in 1 patient. Eleven patients had replacement of one leaflet only, whereas 3 patients required replacement of two leaflets. Concomitant cardiac procedures were performed in 7 patients. RESULTS: No mortalities occurred during the average postoperative follow-up of 61 months (range, 12 to 126 months). Reoperation for TV regurgitation after TV repair with homograft was performed in 3 patients. The remaining 11 patients had minimal symptoms without reintervention for TV regurgitation. CONCLUSIONS: Partial replacement of the TV using a homograft provided good hospital and mid-term outcomes. This strategy might be useful in active infective endocarditis and congenital TV disease.

Spontaneous coronary artery rupture in a young patient: a rare diagnosis for cardiac tamponade.

We report a case of spontaneous coronary artery rupture (SCAR) in a 43-year-old male who presented with symptoms of sudden onset of chest pain and hemodynamic collapse. There were no abnormal electrocardiogram changes and serum troponin was not detected. Acute aortic dissection was suspected but urgent contrast computed tomography (CT) showed a large pericardial effusion with cardiac tamponade. This was later confirmed on trans-oesophageal echocardiogram. The SCAR was seen intra-operatively as an isolated perforation of the posterior descending artery. The patient was successfully managed with direct repair under cardiopulmonary bypass. Postoperative multi-detector dual-source 64-slice CT coronary angiography revealed normal coronary arteries with absence of atherosclerotic plaque in all coronary arterial segments. It is concluded that, though rare, a differential diagnosis of SCAR should be considered in cases of acute chest pain with cardiac tamponade in adult patients of all ages.