Kirinyaga county health team has denied the report that the 12,000 students have tested positive of sexually transmitted diseases.
In a statement on Monday, the county executive for Medical Services, Public Health and Sanitation George Karoki said the "claims cannot be substantiated."
On Thursday, Kirinyaga Central subcounty director for Education, Kennedy Machora, said 12,000 out of 16,000 secondary school students in the subcounty were treated for STIs.
"In the case in point, the data announced is extremely exaggerated and its source cannot be ascertained," Karoki said.
He clarified that the department of health has treated 1,345 cases of STIs in the subcounty and 4,409 cases in the entire county in 2022.
"However, these cases are for the general population and not for a specific cohort of patients," he said.
He further said the department has not, at any point, carried out mass STI testings on secondary school students.
Karoki said community education to caution youth from risky sexual behaviour must be embraced by all sectors.
He, however, said it was crucial for officers in other departments to consult the health department for accurate data.
Karoki fired out at Machora, saying it was reckless and irresponsible of him to make such statement.
"We would like him to present the source of his information, failure to which he should be held accountable," he warned.
The health executive assured that the department is committed to offering high standard preventative and curative services to all, including students.