There is no transitive disease, no safar, no ghoul. He (the narrator) said: I heard Abu Zubair say: Jabir explained for them the word safar. Abu Zubair said: safar means belly. It was said to Jabir: Why is it so? He said that it was held that safar implied the worms of the belly, but he gave no explanation of ghoul. Abu Zubair said: Ghoul is that which kills the travellers. (Using translation from Muslim 2222c)   

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ لَا عَدْوَى وَلَا صَفَرَ وَلَا غُولَ وسَمِعْتُ أَبَا الزُّبَيْرِ يَذْكُرُ أَنَّ جَابِرًا فَسَّرَ لَهُمْ قَوْلَهُ لَا صَفَرَ فَقَالَ أَبُو الزُّبَيْرِ الصَّفَرُ الْبَطْنُ قِيلَ لِجَابِرٍ كَيْفَ؟ فَقَالَ كَانَ يُقَالُ دَوَابُّ الْبَطْنِ قَالَ وَلَمْ يُفَسِّرِ الْغُولَ قَالَ أَبُوالزُّبَيْرِ مِنْ قِبَلِهِ هَذَا الْغُولُ الَّتِي تَغُولُ الشَّيْطَانَةُ الَّتِي يَقُولُونَ