On the other hand, recrudescence means that circulating, multiplying parasites are detected after having persisted in the bloodstream (or elsewhere) at undetectable levels for a period of time, as merozoites (as opposed to hypnozoites).
Recrudescence is also used for malarial recurrence caused by drug-resistant strains of P. vivax and P. ovale where parasites remained in the bloodstream despite treatment.
Re-infection is a recurrence of symptoms due to an infection with a new strain of Burkholderia pseudomallei following the eradication therapy of melioidosis.
Meanwhile, relapse are those who presented with melioidosis symptoms due to failure to clear the infection in the bloodstream after completion of eradication therapy.
[8][9] The bovine viral diarrhoea virus (bovine virus diarrhea) is said to be recrudescent for some time after clinical signs have abated, because antibodies plateau c. weeks 10–12, and are not lifelong, auto infection may potentially occur in the acutely infected non-pregnant animal.