Researchers at the Centers for Disease Control and Prevention in the United States have published a new study warning that the actual number of COVID-19 cases in the United States may be drastically higher than reported. The potentially true number of cases was determined using a probabilistic multiplier model and existing data on infections.
The US has struggled to get enough COVID-19 tests for the population during the pandemic and widespread testing is not yet available or used in many states. This resulted in a large number of people who were probably infected with the new coronavirus behind COVID-19, but who were not officially diagnosed and therefore were not included in the official statistics.
The new study by CDC scientists uses a model based on known data to determine the number of cases that may not have been reported, finding that when it comes to nationally reported cases of out-of-hospital COVID-19, only 1 in 7, 1 diseases may have been identified. When it comes to admissions for COVID-19, the number drops to 1 for every 2.5 cases.
Considering that the officially reported number of COVID-19 cases in the United States at the end of September was around 53 million, the actual number of cases could now be closer to 100 million, based on this study.
The data used for this model stopped at the end of September, which means that there are almost two additional months of infections that are not included in the numbers. The number of COVID-19 cases is expected to increase in the coming weeks due to holidays, despite public health recommendations to stay isolated at home.
The CDC study notes that these are preliminary estimates, but aim to highlight the disease burden for the health system and society in general. The use of models like this can help experts determine where to allocate resources and form mitigation plans in an effort to stem the spread of the disease.