"reported sporadically" is grammatically correct and can be used in written English in certain contexts.
You can use it to describe something that is reported or mentioned occasionally or irregularly. This phrase implies that the reporting is not consistent or constant. Example: "The local newspaper reported sporadically on the increase in crime rates in the city."
At the time of writing, sporadic human infection has been reported sporadically from other locations in northeastern Brazil, consistent with an emerging infectious disease.
Events on the island are reported sporadically through refugee advocates and whistleblowers, but the Australian government's policy of shrouding its offshore detention centres in secrecy has prevented the reporting of many serious incidents.
Among its manifestations is uveitis, with cases of hypopyon uveitis following panretinal photocoagulation for diabetic retinopathy reported sporadically.
Temperatures of surface fumaroles in Owakudani have been measured and reported sporadically, mainly when earthquake swarms took place (Table 1).
To document the existence and investigate the etiology of "thunderstorm asthma," which has been reported sporadically over the past 20 years.
Update: As commenter Lukas Thomas points out below, this would also theoretically prevent scalping issues like the ones that were reported sporadically in China.
So far, normal dopamine transporter density has been reported only sporadically in CBS [19], [45], while none of the few systematic imaging studies in consecutive cohorts ever documented any normal scan [40]–.
Melioidosis has been reported only sporadically from Indonesia and mainly in returning travelers (1 – 3 ).
In that area, outbreaks of congenital SBV were reported rather sporadically during the second wave.
In the 1990s CA-MRSA had been reported only sporadically in Canada [ 7, 8].
We determined that 25 cities out of the original 122 cities reported too sporadically for analysis.
