Three hundred and eighty people in Japan came down with COVID-19 today.
There were 380 new cases of the Coronavirus throughtout Japan today.
ーThree hundred and eighty people in Japan came down with COVID-19 today.
「今日、全国で３８０人がコロナに感染しました」
to come down with ... で「…になる・…にかかる」
「全国で」は in Japan と言えば大丈夫ですよ。
ーThere were 380 new cases of the Coronavirus throughout Japan today.
「今日、全国でコロナの新規感染者数は３８０人でした」
new cases of ... で「…の新規感染者数」
throughout Japan で「全国で」とも言えます。
ご参考まで！
カナダ 
