Case Report
Copyright ©The Author(s) 2004.
World J Gastroenterol. Jun 15, 2004; 10(12): 1844-1847
Published online Jun 15, 2004. doi: 10.3748/wjg.v10.i12.1844
Table 1 Similarities and differences between Cryptosporidium parvum and Cyclospora cayetanensis[10]
SimilaritiesC. cayetanensisC. parvum
Acid-fast staining of oocystsVariable acid-fastAcid-fast
Number of infective units44
(sporozoites) per sporulated oocyst
Completion of life cycle within humansYes, except for sporulationYes
Multiplication outside the host (e.g. in water or food)NoNo
Differences
Size of oocysts8-10 µm in diameter (intermediateAverage width of 4.5 µm and
in size between Cryptosporidiumaverage length of 5 µm
parvum and Isospora belli)
Number of organisms in stools ofTypically excreted in lowOften excreted in somewhat
symptomatic nonimmune hoststo moderate numberhigher numbers
Autofluorescence of oocyst wallYesNo
Internal morphology of sporulated oocystsEach oocyst has 2 internalThe 4 sporozoites are naked
sporocysts, each contains 2 sporozoiteswithin the oocyst
Infectivity of oocysts in freshly excreted stoolMust sporulate outside host toFully sporulated and infectious
become infectiouswhen excreted (sporozoites can
be visualised when oocysts are excreted
Zoonotic potentialHost range unknownInfects virtually all commonly known
wild and domestic mammals
Location in enterocytes of small bowelIntracytoplasmic withinIntracellular, extracytoplasmic, within
a parasitophorous vacuolea parasitophorous vacuole at luminal
in apical supranuclear regionsurface of enterocyte
Susceptibility to antimicrobial agentsTreatment with TMP-SMZ leads toSome antimicrobial agents
both clinical and parasitologic cure(e.g. paromomycin) may cause clinical
improvement, but no agents has been
consistently demonstrated to provide
parasitologic cure