Sequential symptomatic analysis in probable severe acute respiratory syndrome cases

Construction and effectiveness evaluation of a knowledge-based infectious disease monitoring and decision support system

To improve the hospital's ability to proactively detect infectious diseases, a knowledge-based infectious disease monitoring and decision support system was established based on real medical records and knowledge rules. The effectiveness of the system was evaluated using interrupted time series analysis. In the system, a monitoring and alert rule library for infectious diseases was generated by combining infectious disease diagnosis guidelines with literature and a real medical record knowledge map. The system was integrated with the electronic medical record system, and doctors were provided with various types of real-time warning prompts when writing medical records. The effectiveness of the system's alerts was analyzed from the perspectives of false positive rates, rule accuracy, alert effectiveness, and missed case rates using interrupted time series analysis. Over a period of 12 months, the system analyzed 4,497,091 medical records, triggering a total of 12,027 monitoring alerts. Of these, 98.43% were clinically effective, while 1.56% were invalid alerts, mainly owing to the relatively rough rules generated by the guidelines leading to several false alarms. In addition, the effectiveness of the system's alerts, distribution of diagnosis times, and reporting efficiency of doctors were analyzed. 89.26% of infectious disease cases could be confirmed and reported by doctors within 5 min of receiving the alert, and 77.6% of doctors could complete the filling of 33 items of information within 2 min, which is a reduction in time compared to the past. The timely reminders from the system reduced the rate of missed cases by doctors; the analysis using interrupted time series method showed an average reduction of 4.4037% in the missed-case rate. This study proposed a knowledge-based infectious disease decision support system based on real medical records and knowledge rules, and its effectiveness was verified. The system improved the management of infectious diseases, increased the reliability of decision-making, and reduced the rate of underreporting.

Using the internet search data to investigate symptom characteristics of COVID-19: A big data study

Objective

Analyzing the symptom characteristics of Coronavirus Disease 2019(COVID-19) to improve control and prevention.

Methods

Using the Baidu Index Platform (http://index.baidu.com) and the website of Chinese Center for Disease Control and Prevention as data resources to obtain the search volume (SV) of keywords for symptoms associated with COVID-19 from January 1 to February 20 in each year from 2017 to 2020 and the epidemic data in Hubei province and the other top 9 impacted provinces in China. Data of 2020 were compared with those of the previous three years. Data of Hubei province were compared with those of the other 9 provinces. The differences and characteristics of the SV of COVID-19-related symptoms, and the correlations between the SV of COVID-19 and the number of newly confirmed/suspected cases were analyzed. The lag effects were discussed.

Results

Comparing the SV from January 1, 2020 to February 20, 2020 with those for the same period of the previous three years, Hubei's SV for cough, fever, diarrhea, chest tightness, dyspnea, and other symptoms were significantly increased. The total SV of lower respiratory symptoms was significantly higher than that of upper respiratory symptoms (P＜0.001). The SV of COVID-19 in Hubei province was significantly correlated with the number of newly confirmed/suspected cases (r_confirmed = 0.723, r_suspected = 0.863, both p < 0.001). The results of the distributed lag model suggested that the patients who searched relevant symptoms on the Internet may begin to see doctors in 2–3 days later and be confirmed in 3–4 days later.

Conclusion

The total SV of lower respiratory symptoms was higher than that of upper respiratory symptoms, and the SV of diarrhea also increased significantly. It warned us to pay attention to not only the symptoms of the lower respiratory tract but also the gastrointestinal symptoms, especially diarrhea in patients with COVID-19. Internet search behavior had a positive correlation with the number of newly confirmed/suspected cases, suggesting that big data has an important role in the early warning of infectious diseases.

Middle East Respiratory Syndrome Infection Control and Prevention Guideline for Healthcare Facilities

Middle East Respiratory Syndrome (MERS) is an acute viral respiratory illness with high mortality caused by a new strain of betacoronavirus (MERS-CoV). Since the report of the first patient in Saudi Arabia in 2012, large-scale outbreaks through hospital-acquired infection and inter-hospital transmission have been reported. Most of the patients reported in South Korea were also infected in hospital settings. Therefore, to eliminate the spread of MERS-CoV, infection prevention and control measures should be implemented with rigor. The present guideline has been drafted on the basis of the experiences of infection control in the South Korean hospitals involved in the recent MERS outbreak and on domestic and international infection prevention and control guidelines. To ensure efficient MERS-CoV infection prevention and control, care should be taken to provide comprehensive infection control measures including contact control, hand hygiene, personal protective equipment, disinfection, and environmental cleaning.

Certainties and uncertainties facing emerging respiratory infectious diseases: lessons from SARS

Every emerging infectious disease is a challenge to the whole of mankind. There are uncertainties regarding whether there will be a pandemic, if it will be caused by the highly pathogenic H5N1 influenza virus, when or where it will occur, how imminent or how severe it will be. No one can accurately predict if and when a given virus will become a pandemic virus. Pandemic prevention strategies must be based on preparing for the unexpected and being capable of reacting accordingly. There is growing evidence that infection control measures were helpful in containment of severe acute respiratory syndrome (SARS) as well as avian influenza. Compliance of standard infection control measures, intensive promotion of hand and respiratory hygiene, vigilance and triage of patients with febrile illness, and specific infection control measures are key components to contain a highly contagious disease in hospital and to protect healthcare workers, patients and visitors. The importance of standard precautions for any patient and cleaning and disinfection for the healthcare environment cannot be overemphasized. SARS illustrated dramatically the potential of air travel and globalization for the dissemination of an emerging infectious disease. To prevent the potential serious consequences of pandemic influenza, timely implementation of pharmaceutical and non-pharmaceutical interventions locally within the outbreak area is the key to minimizing global spread. Herein, we relate our perspective on useful lessons derived from a review of the SARS epidemic that may be useful to physicians, especially when looking ahead to the next epidemic.

Symptom combinations associated with outcome and therapeutic effects in a cohort of cases with SARS

Severe acute respiratory syndrome (SARS) is an infectious disease and some of its symptoms were clinically indistinguishable of those from similar diseases. This study aimed to find the symptom combinations associated with adverse outcome and the therapeutic effects in a cohort of patients with probable SARS retrospectively. In 2003, 123 SARS cases in Beijing were subjected to a strictly western medicine (WM) treatment, or a combined treatment (WM plus Herba houttuyniae injection, addition of individualized herbal treatments when necessary), of which 115 were followed till death or discharge; 8 were transferred and lost to follow-up. In both treatment groups, clinical manifestations were evaluated daily; development of signs and symptoms, and their possible relationship with outcome, were assessed. The relationships between these sign/symptom complexes and outcome under two treatment protocols were evaluated and differences were noted. Dynamic symptom combinations, dividing into the early, the medium-term and the durational symptom clusters, were identified as likely being related to the adverse outcomes of SARS (p < 0.05, p < 0.01). Compared with a strictly WM treatment, the combined treatment resulted in a longer hospital stay (p = 0.028), a non-statistically significant mortality rate decrease (combined treatment: 9.6% versus WM: 11.1%), and a significant improvement of arthralgia and myalgia (p < 0.05) in the early symptom cluster. Additionally, the combined protocol improved arterial oxyhemoglobin saturation significantly at day 22 (p < 0.05). In conclusion, the progress and outcome of SARS may be associated with specific temporal patterns of development in combination of several non-specific signs and symptom complexes, which are also helpful for evaluating the therapeutic effects on SARS patients.

Chest radiograph screening for severe acute respiratory syndrome in the ED

The purpose of the study was to evaluate the use of chest radiography for the screening of severe acute respiratory syndrome (SARS). We retrospectively analyzed all patients who attended an Emergency Department SARS screening clinic during the outbreak in Hong Kong, from March 10 to June 5, 2003. Patients with clinical and epidemiologic suspicion of SARS were evaluated by serial chest radiography. All radiographs were reported by consensus from 2 radiologists, blinded to the clinical records. The prevalence of SARS was 13.3% among 1328 patients included. The initial radiograph had sensitivity 50.3%, specificity 95.0%, positive likelihood ratio 10.06, negative likelihood ratio 0.52, positive predictive value 61.5%, and negative predictive value 92.3% for diagnosing SARS. Serial chest radiography had sensitivity 94.4%, specificity 93.9%, positive likelihood ratio 15.48, negative likelihood ratio 0.06, positive predictive value 71.4%, and negative predictive value 99.0%. The initial chest radiograph has poor sensitivity, and serial radiographs are required to rule out SARS.

Adverse effects of ribavirin and outcome in severe acute respiratory syndrome: experience in two medical centers

STUDY OBJECTIVES

To assess the effect of ribavirin-induced anemia on the outcome of severe acute respiratory syndrome (SARS).

DESIGN

A retrospective observational study.

SETTING

Two medical centers in Taiwan.

PATIENTS

Forty-four patients with SARS who received ribavirin and 7 patients with SARS who did not receive ribavirin.

MEASUREMENTS AND RESULTS

The mean peak C-reactive protein and lactate dehydrogenase levels were higher in SARS patients who were receiving ribavirin therapy than in SARS patients who were not receiving ribavirin therapy. The mortality was also higher, but the difference was not statistically significant. On multivariate analysis, hemoglobin level was an independent prognostic correlate of hypoxemia or mortality (odds ratio, 2.0; 95% confidence interval, 1.1 to 3.8; p = 0.03). The hemoglobin began decreasing in two thirds of SARS patients (32 of 44 patients; 73%) who were receiving ribavirin 3 days after therapy with the antiviral drug was started. Patients with a drop in hemoglobin level of > 2 g/dL had a significantly higher mortality rate than the other patients. Hypoxemia developed in one third of SARS patients (17 of 44 patients; 39%) who were receiving ribavirin, all of whom were anemic. Of the 17 hypoxemic patients, 11 (65%) had a drop in hemoglobin of > 2 g/dL, and 4 patients (24%) required a blood transfusion. The mean slope of the hemoglobin decrease was significantly steeper (p = 0.001) in hypoxemic patients with SARS who were receiving ribavirin than in the nonhypoxemic patients with SARS who were receiving ribavirin. Only one of seven SARS patients (14%) who was not receiving ribavirin became anemic, but this individual was not hypoxemic. Eventually, 5 of 17 hypoxemic and anemic SARS patients (29%) who were receiving ribavirin died. The combination of hypoxia with anemia was thus significantly associated with a higher mortality (p < 0.001).

CONCLUSIONS

Hypoxia combined with anemia increased the risk for death in SARS patients. Unless ribavirin can be shown to be effective against SARS-coronavirus, the risk of anemia posed by this drug argues against its use in SARS patients.

Severe acute respiratory syndrome coronavirus pathogenesis, disease and vaccines: an update

BACKGROUND

A novel coronavirus has recently been identified as the cause of severe acute respiratory syndrome (SARS-CoV). The ability of this family of positive strand RNA viruses to move between species and cause severe disease in humans, with the potential for pandemic spread, has been confirmed.

METHODS

An understanding of the disease and its pathogenesis and the genetics of coronavirus infections, as well as strategies to treat or prevent coronavirus infections, are essential. The history of coronavirus vaccines and the occurrence of laboratory-associated SARS-CoV infections underscore the need for stably attenuated strains of SARS-CoV and other coronaviruses.

RESULTS

Rapid progress has been made in understanding the clinical disease of SARS in adults and children. In adults, systemic infection with clinical and biochemical abnormalities, as well as respiratory infection, may be the rule. SARS is much milder in children younger than 12 years old than it is in adolescents and adults. In children age 12 years and younger, symptoms are generally nonspecific and cold-like. Numerous approaches to the development of SARS-CoV vaccines have been undertaken, and there is evidence that antibodies to the spike protein may be protective from replication and pathology in animal models.

CONCLUSIONS

The availability of reverse genetic systems has made it possible to engineer and recover coronavirus variants that contain multiple genetically stable mutations that grow well in culture but are attenuated for replication, virulence or both. Such variants will be platforms for the safe growth of SARS-CoV and candidates for live attenuated vaccines.

Severe acute respiratory syndrome (SARS) in intensive care units (ICUs): limiting the risk to healthcare workers

The global epidemic of severe acute respiratory syndrome (SARS) during the first half of 2003 resulted in over 8000 cases with more than 800 deaths. Many of those who eventually died, did so in the critical (intensive) care units of various hospitals around the world, and many secondary cases of SARS arose in healthcare workers looking after such patients in these units. Research on SARS coronavirus (SARS CoV) demonstrated that this virus belongs to the same family of viruses, the Coronaviridae that causes the common cold, with some important differences. Properties of this virus have been discovered which can be used to develop important infection control policies within hospitals to limit the number of secondary cases. These properties include environmental survival, transmissibility, viral load in various organs and fluids and periods of symptomatic illness during which infectivity is greatest. Various barrier methods were used throughout the epidemic to protect healthcare workers from SARS, with varying degrees of success. Treatment of SARS patients has mainly involved steroid therapy, with or without ribavirin, but there is no consensus on the best treatment protocol, as yet. This review focuses on the implications of SARS for healthcare workers and patients on critical care units.