Contact Tracing over Uncertain Indoor Positioning Data

Pandemics often cause dramatic losses of human lives and impact our societies in many aspects such as public health, tourism, and economy. To contain the spread of an epidemic like COVID-19, efficient and effective contact tracing is important, especially in indoor venues where the risk of infection is higher. In this work, we formulate and study a novel query called Indoor Contact Query (<sc>ICQ</sc>) over raw, uncertain indoor positioning data that digitalizes people's movements indoors. Given a query object <inline-formula><tex-math notation="LaTeX">$o$</tex-math></inline-formula>, e.g., a person confirmed to be a virus carrier, an <sc>ICQ</sc> analyzes uncertain indoor positioning data to find objects that most likely had close contact with <inline-formula><tex-math notation="LaTeX">$o$</tex-math></inline-formula> for a long period of time. To process <sc>ICQ</sc>, we propose a set of techniques. First, we design an enhanced indoor graph model to organize different types of data necessary for <sc>ICQ</sc>. Second, for indoor moving objects, we devise methods to determine uncertain regions and to derive positioning samples missing in the raw data. Third, we propose a query processing framework with a close contact determination method, a search algorithm, and the acceleration strategies. We conduct extensive experiments on synthetic and real datasets to evaluate our proposals. The results demonstrate the efficiency and effectiveness of our proposals. IEEE

Global Forum of Cancer Surgeons: Cancer Surgery During the COVID-19 Pandemic: Impact and Lessons Learned.

BACKGROUND: The purpose of this article is to summarize the opinions of the surgical oncology leaders from the Global Forum of Cancer Surgeons (GFCS) about the global impact of COVID-19 pandemic on cancer surgery. METHODS: A panel session (virtual) was held at the annual Society of Surgical Oncology 2021 International Conference on Surgical Cancer Care to address the impact of COVID-19 on cancer surgery globally. Following the virtual meeting, a questionnaire was sent to all the leaders to gather additional opinions. The input obtained from all the leaders was collated and analyzed to understand how cancer surgeons from across the world adapted in real-time to the impact of COVID-19 pandemic. RESULTS: The surgical oncology leaders noted that the COVID-19 pandemic led to severe disruptions in surgical cancer care across all domains of clinical care, education, and research. Several new changes/protocols associated with increased costs were implemented to deliver safe care. Leaders also noted that preexisting disparities in care were exacerbated, and the pandemic had a detrimental effect on well-being and financial status. CONCLUSIONS: The COVID-19 pandemic has led to severe disruptions in surgical cancer care globally. Leaders of the GFCS opined that new strategies need to be implemented to prepare for any future catastrophic events based on the lessons learned from the current events. The GFCS will embark on developing such a roadmap to ensure that surgical cancer care is preserved in the future regardless of any catastrophic global events.

EARLIEST SYMPTOMS OF PRESENTATION IN COVID-19 PATIENTS IN TERTIARY CARE HOSPITAL

Objective: To determine the frequency of earliest symptoms of COVID-19 infection among patients with confirmed SARS-COVID-19 infection. Study Design: Cross-sectional analytical study. Place and Duration of Study: Combined Military Hospital Multan, from Jun to Dec 2021. Methodology: Data from 299 patients admitted in tertiary care settings was collected on a questionnaire. Patients regardless of gender and age who had confirmed COVID-19 infection through Real Time Polymerase Chain Reaction (RT-PCR) were included in the study. A nonprobability consecutive sampling technique was used to select samples. Data was entered and analyzed through SPSS version 22. Frequencies and percentages of various presenting symptoms were calculated. Sample size calculated at 95% level of confidence, 1% required precision, and 27% anticipated population proportion were 299. The over-all difference in frequencies of symptoms in various groups was compared by using chi-square test. p-value <0.05 was taken as significant. Results: A total of 299 participants were included in this analysis. The median age for participants (interquartile range [IQR]) was 46 (36-54) years. Among 299 adults the reported symptoms were cough 238 (79.6%), fever 176 (58.7%) and, dyspnea 113 (37.8%). Only 78 (26.1%) of participants with confirmed infection reported having all three symptoms of cough, fever, and dyspnea. Other reported symptoms in patients were diarrhea 54 (18.1%), fatigue 128 (42.8%), myalgia 113 (37.8%), and anosmia 98 (32.8%). There was no significant difference in the frequency of symptoms across both genders. Conclusion: The most frequent symptoms of COVID-19 are cough, fever, and dyspnea. © 2021, Army Medical College. All rights reserved.

DISAPPEARANCE OF ANTIBODIES IN COVID-19 MYTHS ORREALITY

Objective: To explore the disappearance of neutralizing antibodies from patients, their myths, and facts. Study Design: Cross-sectional study. Place and Duration of Study: Combined Military Hospital Multan Pakistan, from Jul 2021 to Aug 2021. Methodology: A total of 100 blood samples were collected from 100 COVID-19 patients. These 100 patients were followed up for a period of 3 months. Antibodies were determined with the modified neutralization assay method and enzyme-linked immuno-sorbent assay (ELISA). Results: The antibody level by NA and ELISA peaked on days 30-35 then decreased slightly. In multivariate analysis, patients aged 25-35, 36-56, and 57-84 years had a higher neutralizing antibody level than those aged 10-21 years. The patient with the worst clinical manifestation had a higher neutralizing antibody titer. In serum samples, IgG was undetectable at 18.3% and 11% and the geographical mean reciprocal titers dropped from 244 at 3-month period and neutralizing antibodies, the geographical mean reciprocal titers dropped from 874 at 3 months. Conclusion: All COVID-19 patients were seropositive and significantly neutralizing antibody response. Neutralizing antibody levels depend on the time after the onset of symptoms, age, and severity of the disease. © 2021, Army Medical College. All rights reserved.