There are 18 words that start with 'infec'.
| infect | infects |
| infected | infecter |
| infector | infecund |
| infectant | infecters |
| infecting | infection |
| infective | infectors |
| infections | infectious |
| infectivity | infectiously |
| infectivities | infectiousness |
Note: These 18 words that start with 'infec' are found from the USA & Canada version of the tournament Scrabble word list.