Recrudescence is when symptoms return after a symptom-free period and the origin is parasites that survived in the blood as a result of inadequate or ineffective treatment. Relapse is when symptoms reappear after the parasites have been eliminated from the blood and the recurrence source is activated parasites which had persisted as dormant hypnozoites in liver cells. Relapse commonly occurs after 8–24 weeks and is often seen in P. vivax and P. ovale infections. However, relapse-like P. vivax recurrences are probably being over-attributed to hypnozoite activation. Some of them might have an extra-vascular or sequestered merozoite origin, making those recurrences recrudescences, not relapses. Newly recognised, non-hypnozoite, possible contributing sources to recurrent peripheral P. vivax parasitemia are erythrocytic forms in the bone marrow and spleen. P. vivax malaria cases in temperate areas often involve overwintering by hypnozoites, with relapses beginning the year after the mosquito bite. Reinfection means that the parasites responsible for the past infection were eliminated from the body but a new parasite(s) was introduced. Reinfection cannot readily be distinguished from relapse and recrudescence, although recurrence of infection within two weeks of treatment for the initial malarial manifestations is typically attributed to treatment failure. But doing this is not necessarily correct. People may develop some immunity when exposed to frequent infections. Pathophysiology
Malaria infection develops via two phases: one that involves the liver (exoerythrocytic phase), and one that involves red blood cells, or erythrocytes (erythrocytic phase).
Diagnosis
Diagnosis is by biopsy, visualising the fungi under the microscope and culture, which show characteristic fungal filaments and vesicles characteristic of the fungi. Other tests include ELISA, immunodiffusion, and PCR with DNA sequencing (so-called DNA barcoding).X rays and ultrasonography may be carried out to assess the extent of the disease. X rays findings are extremely variable. The disease is most often observed at an advanced stage that exhibits extensive destruction of all bones of the foot. Rarely, a single lesion may be seen in the tibia where the picture is identical with chronic osteomyelitis. Cytology of fine needle aspirate or pus from the lesion, and tissue biopsy may be undertaken sometimes. Some publications have claimed a "dot in a circle sign" as a characteristic MRI feature for this condition (this feature has also been described on ultrasound). Differential diagnosis
The following clinical conditions may be considered before diagnosing a patient with mycetoma:

Tuberculous ulcer
Kaposis sarcoma, a vascular tumour of skin usually seen in AIDS. Leprosy
Syphilis
Malignant neoplasm
Tropical ulcer
Botryomycosis, a skin infection usually caused by the bacteria Staphylococcus aureus. Prevention
No vaccine is available. Simple hygienic precautions like wearing shoes or sandals while working in fields, and washing hands and feet at regular intervals may help prevent the disease. Treatment
Surgery combined with itraconazole may be given for up to year when the grains are black. Posaconazole is another option. Voriconazole can be used for infections caused by Fusarium species.Ketoconazole has been used to treat eumycetoma but has many side effects.