To prevent the spread of any infectious disease, such as coronavirus disease 2019 (COVID-19) Contact tracer is a vital tool. Contact tracing is a method to identify people who are at a high risk of contracting the disease by contacting someone who is affected. If necessary treatment or advice is offered to the patient to ensure that they are isolated to stop the spread of the disease. Typically contact tracing is utilized for sexually transmitted infections, where the definition of contact is clearly defined.
Study: The low impact of contact tracing in a university for COVID-19 may be due to social distancing, asymptomatic transmission and asymptomatic transmission. Image Credit: Tikhonova Yana/ Shutterstock
The Social Contact Survey (SCS) which collected information on the patterns of social contact in the general British population, developed mathematical models to assess infectious diseases. However, university populations differ in many ways when compared to the overall population. Students are generally younger adults who have more social contacts than the average person and reside in communal housing. Additionally, due to the restrictions that were put in place during the COVID-19 pandemic, the way that people socialize has dramatically changed. In June 2020, the Coronavirus Questionnaire (CON-QUEST) survey was launched to capture any new contact patterns in students and university personnel during the pandemic.
The two surveys provided researchers from the University of Bristol to examine how university populations changed in response to social constraints. They also studied the effectiveness of traceability of contacts in such a setting. The effectiveness of contact tracing is evaluated by its capacity to limit the degree to which an infected individual spreads the disease, as well as the scheme’s ability to back-trace and identify symptomatic index cases.
A preprint version of the study, which is still to be reviewed by a peer The study is available on the medicalRxiv* server.
The CON-QUEST survey reported a median number of daily contacts to the value of two, compared to nine from the university-affiliated subset of the SCS. The proportion of respondents reporting small amounts of daily contacts was higher in the CON-QUEST data when compared to the SCS data. The percentage of respondents who reported having one, two, or three contacts per day is about a third greater in the CON-QUEST data when compared to the SCS subset data. In the SCS subset data the number of daily contacts was higher than the CON-QUEST data. The SCS subset also had a higher number of respondents with high numbers of contacts.
Comparing the data from 2010 and 2020’s social connections were longer. The CON-Quest participants reported more frequent social interactions than those who participated in the SCS survey. In addition to the longer duration of social contacts participants who participated in the CON-QUEST survey reported more frequent contact in comparison to those who participated in the SCS survey. Participants in the CON-QUEST survey had a higher number of occasions when contacts occurred “eight or more times” than those in the SCS survey.
The spread of severe acute respiratory syndrome coronavirus 2 infections in the university population seems to depend on the index case’s infectiousness, transmission rate, as well as if contact tracing was used. Research has shown that an increase in the transmission rate results in an increase the number of secondary cases. Without contact tracking the symptomatic index cases lead to an increased number of secondary cases compared to index cases that are not symptomatic due to their greater infectivity.
However, contact tracing could significantly reduce the spread of COVID-19 in symptomatic index patients. Contact tracing is believed to have little impact on the number of cases that are asymptomatic. Contact tracing can reduce secondary cases by about 56% in symptomatic index cases. The most significant impact is for cases with lower transmission rates.
This study compared the results of a poll conducted before the pandemic and one conducted during the pandemic by examining the duration of the survey, frequency, and number of contacts that were reported in each survey. From the available data they constructed an ego-centric network to model the real-life transmission of COVID-19 from index cases to people who they encounter. Contact tracing was then introduced to investigate three scenarios in which the index case was always manifestly symptomatic, but never asymptomatic, or asymptomatic with a probability dependent on age.
The pattern of communication within university communities changed during the time of government-imposed restrictions on social gatherings. The majority of students stayed away from contact for prolonged periods and also with a higher frequency. Because of these changes in behavior, decreases in the number of secondary infections observed. It is expected for university populations to have a high percentage of patients who are not symptomatic, so in cases such as this mass testing is needed to determine the asymptomatic individuals and utilize contact tracing to its greatest potential.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Content Source: https://www.news-medical.net/news/20211116/Spread-of-COVID-19-and-effectiveness-of-contact-tracing-in-a-university-population.aspx