I have just gone through Narada Samhita, Sanskrit text with Hindi translation book available on Internet Archive but I have not found the mentioned verse in it.
All the sites/articles citing this shloka are saying that (interpretation of the mentioned verse) "In the Samvatsar called PariDhawi, there will be war between the kings and an epidemic will spread. Rain will be unusual and all beings will be sad.
There are total 55 Adhayayas (chapters) in Narada Sanhita. 3rd chapter deals with Samvatsara. And here is a description of Paridhavi Samvatsara in verse 62 (which is quite different than what's claimed):
Transliterating and Translating:
anarghyāmayarogebhyo bhītirītirniraṃtaram ॥
paridhāvīvatsare tu nṛṇāṃ vṛṣṭistu madhyamā॥62॥
In the year named Paridhavi, there be expensive food etc., continuous fear of diseases and moderate rain.
Here there is no mention of "महारोगो" or epidemic. Although diseases are mentioned in general but that is not a special case of Paridhavi Samvatsara, diseases are mentioned for few other Samvatsaras also.