At least 28 states are not following CDC guidelines on reporting new Covid-19 cases, half of which saw the trend of new cases increasing in the last week.

Those states are not reporting probable cases, according to the daily case count listed on the CDC’s website. Probable cases include those that show evidence of an infection without the confirmation of a lab test and cases where coronavirus was listed as a cause or contributing cause of death but are not confirmed with a lab test.
Some of the states with the largest populations, like California, Florida, New York and Texas, are among those listed as not reporting probable cases, despite CDC guidance that they should be included in the case count.
This comes as 26 states see an increased or steady rate of new cases. Accurate rates of new cases are among the metrics that help officials track how the disease is spreading in the US and make decisions about how to reopen and loosen restrictions put in place to mitigate its impact.
Though coronavirus reporting guidelines are voluntary, states not reporting probable cases likely undercount the number of people infected and make it difficult for officials to get the true picture of where the nation stands in the midst of a pandemic that has rocked almost every aspect of life.