^^^ I was thinking the same thing.
Here are the treatment options for both possibilities.
Acriflavine: I have no first-hand experience with this medication, so everything I know about it comes from one LFS (treating Brooklynella), Google Scholar or other literature. It supposedly is effective against protozoans, bacterial infections and external fungal diseases; however Brook & Uronema are the only two I would bank on. It also is supposedly “reef safe”, so long as it is not mixed with any other medication (very important!)
How To Treat - Follow the directions on the label of whatever product you are using. Acriflavine is often mixed with other medications; howeverAcriflavine-MS is the pure form (and most likely to be “reef safe.”)
Pros - Alternative treatment for Brooklynella & Uronema (useful in locales where formalin is banned); possibly “reef safe.”
Cons/Side Effects - Acriflavine is a “new” medication (to me), so it’s full range of effect is not completely understood. Same goes for possible side effects.
Antibiotics: Treats bacterial infections, which are oftentimes “secondary” to preexisting parasitic infestations.
How To Treat - Follow the directions on the label of whatever product you are using. Always use a broad spectrum antibiotic medication i.e. one that treats both gram-positive and gram-negative bacterial diseases (very important). Examples of this include Furan-2, Kanamycin akaSeachem Kanaplex, Nitrofuracin Green Powder, Triple Sulfa Powder or a combination of using both Erythromycin & Minocycline. The latter can be accomplished (albeit expensively) by using freshwater Maracyn 1 & 2 and then doubling the dosage for saltwater use. When battling a particularly nasty bacterial infection, combining Furan-2, Kanaplex and metronidazole (ex. Seachem MetroPlex) can be very effective (and safe).Props to “hedgedrew” for enlightening me of this.
Normally you have to do 4 doses to complete a full course of treatment. The instructions may say to dose every 24 hours, and perform water changes at certain intervals. In my experience, you often have to do 2 full courses of treatment (or 8 doses total) before a fish will show signs of improvement (antibiotics are notoriously slow acting with fish). If a fish shows no signs of improvement after the second full course, then it’s time to try a completely different medication. Just like with humans, sometimes a certain fish will respond better to a different antibiotic. You can run activated carbon at any time when you wish to end treatment.
Pros - One of the few medications that can safely be mixed with others. You can use antibiotics in conjunction with just about everything.
Cons/Side Effects - Appetite suppression, depletes the water of oxygen (so provide additional gas exchange).