JMIR Publications

ABSTRACT

Background:

A better understanding of SARS-CoV-2 infection risk among Hispanic and Latino populations and in low-resource settings in the U.S. is needed to inform control efforts and strategies to improve health equity. Puerto Rico has a high poverty rate and other population characteristics associated with increased vulnerability to COVID-19 and limited data to determine community incidence.

Objective:

This report describes the protocol and baseline seroprevalence of SARS-CoV-2 in a prospective community-based cohort study (COCOVID) to investigate SARS-CoV-2 infection incidence and morbidity in Ponce, Puerto Rico.

Methods:

In June 2020, we implemented the COCOVID study within the Communities Organized to Prevent Arboviruses (COPA) project platform among residents of 15 communities in Ponce, Puerto Rico age 1 year and older. Weekly, participants answered questionnaires on acute symptoms and preventive behaviors and provided anterior nasal swab samples for SARS-CoV-2 PCR testing; additional anterior nasal swabs were collected for expedited PCR testing from participants that reported ≥1 COVID-like symptoms. At enrollment and every 6 months during follow-up, participants answered more comprehensive questionnaires and provided venous blood samples for SARS-CoV-2 IgG antibody testing (indicative of seroprevalence). Weekly follow-up activities concluded in April 2022 and 6-month follow-up in August 2022.

Results:

We enrolled a total of 1,030 participants from 388 households. Relative to the general populations of Ponce and Puerto Rico, our cohort overrepresented middle-income households, employed and middle-aged adults, and older children (P<.001). Almost all participants (99.6%) identified as Latino/a, 17% had annual household incomes less than $10,000, and 45% reported one or more chronic medical conditions. Baseline SARS-CoV-2 seroprevalence was low (1%) overall and increased with later study enrollment time (P=.003).

Conclusions:

The COCOVID study will provide a valuable opportunity to better estimate the burden of SARS-CoV-2 in the Ponce region, assess the limitations of surveillance, and inform mitigation measures in Puerto Rico and other similar populations.