Sero-Prevalence Findings from Metropoles in Pakistan: Implications for Assessing COVID-19 Prevalence and Case-Fatality within a Dense, Urban Working Population

Guesstimating the COVID-19 burden: what is the best model?

“…Many countries in the developing world are currently facing large data deficits in terms of their official number of COVID-19 cases reported. Seroprevalence findings from a large-scale census conducted on a dense, urban, working population in Pakistan from April to July 2020 indicated that by July 6, 2020, 4.11 million people in Pakistan had been infected with COVID-19, which was 17.7 times higher than the official number of 231,818 symptom-based PCR cases reported by the government within the same time frame ( Javed et al., 2020 ). This is because asymptomatic carriers of the virus had not been presenting at government-approved facilities for PCR tests; hence this testing methodology failed to capture the true prevalence of the disease within the Pakistani population.…”

“…Hence, antibody kits offer a reliable alternative to detecting COVID-19 infections which would otherwise not be detected by a PCR test when the viral load is low. This is because antibody kits depend upon detecting the response of the body rather than detecting the virus or antigen itself, which allows antibody kits to detect exposure to COVID-19 before the onset of symptoms ( Javed et al., 2020 ). Moreover, seroprevalence studies can allow us to assess the prevalence of the disease rather than just the incidence as indicated through PCR testing of symptomatic individuals.…”

“…In Pakistan, there is an urgent need to bridge the large data deficit between the actual numbers of COVID-19 cases using serologic tests, compared to only those individuals presenting to government-approved facilities for PCR testing. Given this gap in data, Pakistan's first 100% census seroprevalence study was conducted across various major cities of Pakistan using the IgG/IgM Test Kit (Colloidal gold) with follow-up and sequential testing after every 15–20 days ( Javed et al., 2020 ). The sample size included an adult, working population aged 18–65 years, recruited from dense, urban workplaces including factories, corporates, restaurants, media houses, schools, banks, health-care providers in hospitals, and families of positive cases across various cities in Pakistan, including Karachi, Lahore, Multan, Peshawar, and Quetta ( Javed et al., 2020 ).…”

“…Given this gap in data, Pakistan's first 100% census seroprevalence study was conducted across various major cities of Pakistan using the IgG/IgM Test Kit (Colloidal gold) with follow-up and sequential testing after every 15–20 days ( Javed et al., 2020 ). The sample size included an adult, working population aged 18–65 years, recruited from dense, urban workplaces including factories, corporates, restaurants, media houses, schools, banks, health-care providers in hospitals, and families of positive cases across various cities in Pakistan, including Karachi, Lahore, Multan, Peshawar, and Quetta ( Javed et al., 2020 ). This was the first of its kind, large-scale, cross-sectional study conducted among the low-risk, urban, and working population.…”

“…Emerging research on COVID-19 transmission illustrates how asymptomatic infections within a country may be much higher than the number of polymerase chain reaction (PCR) reported cases ( Bendavid et al, 2020 ). Seroprevalence findings from a large-scale census in Pakistan from April to July 2020 indicated 17.7 times higher prevalence as compared to traditional PCR government testing within the same time frame ( Javed et al., 2020 ). Hence, an effective approach to pandemic response would involve a synergistic model encompassing both PCR testing and mass-level screening via serologic test kits in order to capture the true extent of the disease within the population.…”