Neighborhood unfold of COVID-19 in New York Metropolis revealed by contact tracing

In a current examine posted to the Research Square* preprint server, researchers assessed the transmission of extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in New York Metropolis (NYC) communities by contact tracing.

Study: Contact tracing reveals community transmission of COVID-19 in New York City. Image Credit: WESTOCK PRODUCTIONS
Research: Contact tracing reveals community transmission of COVID-19 in New York City. Picture Credit score: WESTOCK PRODUCTIONS


An in depth understanding of SARS-CoV-2 transmission in community-based settings is important to formulate tailor-made public well being methods and insurance policies for specific geographical areas and communities with persistent and spatial SARS-CoV-2 transmission. Analyzing community-level SARS-CoV-2 transmission has been difficult since group testing, and surveillance knowledge are missing. Moreover, the impression of preventive measures on SARS-CoV-2 group transmission in city areas wants additional analysis.

In regards to the examine

Within the current examine, researchers assessed SARS-CoV-2 transmission in NYC communities by contact tracing.

Contact tracing knowledge have been obtained from case investigations and SARS-CoV-2 antigen and molecular check reviews for 644,029 coronavirus illness 2019 (COVID-19) circumstances and their shut contacts in NYC in the course of the second wave of the COVID-19 pandemic to quantify the spatial sample of community-level SARS-CoV-2 transmission. The examine was performed between 1 October 2020 and 10 Might 2021.

Instances reported to the NYC division of well being and psychological hygiene (DOHMH) and traced by the NYC check & hint corps have been analyzed for characterizing the operational efficiency of contact tracing and understanding SARS-CoV-2 within- and cross-ZIP code SARS-CoV-2 transmission. Self-reported chains of SARS-CoV-2 transmission have been reconstructed by linking contact tracing information to the laboratory-confirmed COVID-19 circumstances and mapped throughout modified ZIP code tabulation areas (MODZCTAs).

For symptomatic COVID-19 circumstances, the workforce estimated the an infection date primarily based on the SARS-CoV-2 incubation interval talked about in a earlier examine. For asymptomatic COVID-19 circumstances, the date of pattern assortment was used to estimate the date of an infection by making use of Bayesian inference to findings of viral load modeling.

Additional, the impression of public well being interventions on group transmission of SARS-CoV-2 was evaluated. Knowledge on 4,642 occasions of non-household SARS-CoV-2 transmission have been obtained from cell phones with documented weekly counts of individuals at factors of curiosity (POIs) resembling grocery shops, eating places, bars, and gymnasiums in geographical areas with completely different ZIP codes used. Conditional autoregressive (CAR) modeling was carried out with Poisson generalized linear blended fashions (GLMM) to evaluate the spatial transmission of SARS-CoV-2 in NYC communities.


Samples have been obtained, findings have been reported to DOHMH inside two days, and nearly all index circumstances (97%) have been summoned by contact tracers inside two days of sending reviews to DOHMH. Over 68% of shut contacts have been summoned the day reviews have been despatched to the check & hint contact tracing workforce.

Over 66% of contacts underwent SARS-CoV-2 testing inside seven days of receiving the notification. For symptomatic SARS-CoV-2 infections, 13% and 87% of people underwent testing previous to and publish the onset of COVID-19 symptoms, respectively.

A lot of the index circumstances have been 20 to 49 years previous, with frequent social interactions amongst equally aged people and larger inter-generation interactions in households. SARS-CoV-2 transmission chains have been heterogeneous and comprised 947,042 individuals belonging to 242,486 disconnected clusters. Clusters of SARS-CoV-2 publicity have been various and ranged from single spreader publicity networks to these with a number of spreaders.

Greater than 50% of clusters belonged to Brooklyn and Queens and inside the clusters, 59% (n=1,195 people) of traced index circumstances comprised within-ZIP code contacts and 42% (n=817 people) cross-ZIP contacts. As well as, 58,474 clusters of potential SARS-CoV-2 transmission have been recognized, comprising two people on common, representing 20% (n=135,478 people) of reported COVID-19 circumstances.

The most important recognized cluster of SARS-CoV-2 transmission comprised 12 circumstances with a most of seven secondary COVID-19 circumstances per index case. Cross-ZIP code transmission occasions primarily occurred inside a radius of 10 km; nonetheless, transmission ≤40 km was noticed. Out of 72,191 occasions of SARS-CoV-2 transmission in recognized residential areas, 11% (n=7,826) of cross-ZIP codes have been discovered to be tightly interlinked by SARS-CoV-2 publicity and dissemination.

The within-ZIP code and cross-ZIP code SARS-CoV-2 transmission lowered by 28% and 15%, respectively, amongst 12.5% of people who acquired COVID-19 vaccinations lately. Larger protection of vaccination and fewer POI guests have been related to decrease within-ZIP code and cross-ZIP code SARS-CoV-2 transmission.


General, the examine findings highlighted the spatial sample of SARS-CoV-2 transmission in NYC communities and potential measures for curbing SARS-CoV-2 transmissions resembling vaccination and lowered POI visits in high-prevalence communities.

*Necessary discover

Analysis Sq. publishes preliminary scientific reviews that aren’t peer-reviewed and, due to this fact, shouldn’t be thought to be conclusive, information medical apply/health-related habits, or handled as established info.

Journal reference:



Leave a Reply