Praziquantel efficacy and long-term appraisal of schistosomiasis control in Pemba Island.
OBJECTIVE
To determine whether praziquantel (PZQ) has retained its efficacy against Schistosoma haematobium on Pemba Island after 20 years of mass administration--albeit discontinuous--and to analyse retrospectively the performance of schistosomiasis control programmes.


METHODS
A sample of Pemba schoolchildren was examined before and after PZQ treatment by urine filtration, macro- and micro-haematuria and viability of excreted eggs.


RESULTS
Although 5% of treated children continued to pass some eggs in the urine up to the seventh week after PZQ administration, none of these eggs was viable, indicating an effective schistosomicidal activity followed by a slow release of dead eggs from host tissues.


CONCLUSIONS
No signs of PZQ resistance could be detected in the population under study. An overall retrospective analysis of schistosomiasis control activities in Pemba Island revealed that mass drug administration is clearly effective in reducing infection prevalence, but soon after interruption of drug distribution prevalence returns rapidly to pre-intervention levels.
Guidi
A
A
Institute of Cell Biology, National Research Council, Monterotondo, Rome, Italy.
Andolina
C
C
Makame Ame
S
S
Albonico
M
M
Cioli
D
D
Juma Haji
H
H
D000293:Adolescent; D000818:Animals; D002648:Child; D015331:Cohort Studies; D004334:Drug Administration Schedule; D004351:Drug Resistance; D006801:Humans; D007195:Indian Ocean Islands / Q000453:epidemiology; D010270:Parasite Egg Count; D011223:Praziquantel / Q000627:therapeutic use*; D015995:Prevalence; D012189:Retrospective Studies; D012548:Schistosoma haematobium / Q000302:isolation & purification; D012553:Schistosomiasis haematobia / Q000188:drug therapy* / Q000453:epidemiology; D012556:Schistosomicides / Q000627:therapeutic use*; D012621:Seasons; D016896:Treatment Outcome
D012556:Schistosomicides; D011223:Praziquantel