Occurrence of Cryptosporidium oocysts and Giardia cysts in water supplies of San Pedro Sula, Honduras

Abstract

During June 1996, water supplies of the city of San Pedro Sula, Honduras, were sampled to obtain an assessment of Cryptosporidium oocyst and Giardia cyst concentrations. Each sample was concentrated and stained with an indirect immunofluorescent antibody, and parasites were counted through microscopic analysis. In three surface water supplies, Cryptosporidium oocyst concentrations ranged from 58 to 260 oocysts per 100 L, and Giardia cysts were present in concentrations ranging from 380 to 2100 cysts per 100 L. Unlike the surface water samples, groundwater had a higher concentration of Cryptosporidium oocysts (26/100 L) than Giardia cysts (6/100 L), suggesting that the groundwater aquifer protects the water supply more effectively from larger Giardia cysts. Cryptosporidium oocyst concentrations are within the typical range for surface water supplies in North America whereas Giardia cyst concentrations are elevated. Efforts should be made to protect raw water from sources of contamination.

Recovery, Bioaccumulation, and Inactivation of Human Waterborne Pathogens by the Chesapeake Bay Nonnative Oyster, Crassostrea ariakensis

“…The concentration of human pathogens from ambient water by C. ariakensis triploids and retention of these pathogens without (or with minimal) inactivation and a very low depuration rate provide evidence that these oysters will present a public health threat to the human food chain if they are harvested from polluted water. This conclusion is reinforced by the concentration of waterborne pathogens (25 cells/liter/day) used in the present study, which was representative of pathogen levels observed in surface waters, including the Chesapeake Bay (9,21,33,34,37). The concentrations of waterborne C. parvum oocysts measured in the Nanticoke, Patuxent, and Potomac Rivers and the Tangier Sound were 79, 31, 10, and 8 oocysts/ liter, respectively (9).…”

“…The inoculum of C. parvum oocysts, G. lamblia cysts, and spores of human-infectious microsporidia simulated the concentration of these pathogens reported for surface waters, including the Chesapeake Bay (9,33,34,37).…”

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

“…These protozoans can be detected in several water sources including wastewaters, surface waters, spring waters, recreational waters, ground waters and drinking waters (Solo-Gabriele et al 1998;Franco et al 2001;Rose et al 2002;Hachich et al 2004;Briancesco & Bonadonna 2005;Ryu & Abbaszadegan 2008;Muchiri et al 2009). …”

Accumulation of human waterborne parasites by zebra mussels ( Dreissena polymorpha ) and Asian freshwater clams ( Corbicula fluminea )

“…Concentration of oocysts and cysts in the Delaware River, New Jersey, USA (drawn by drinking water plants) was 14 and 40 per 5 l, respectively (Atherholt et al 1998), and 260 and 2,100 per 100 l, respectively, in water supplies of San Pedro Sula, Honduras (Solo-Gabriele et al 1998). The present study demonstrated that zebra mussels and Corbicula clams performed very well as indicators for waterborne contamination under the pollution levels reported from surface drinking water supplies (Rose et al 1997;Atherholt et al 1998;Solo-Gabriele et al 1998). This conclusion is reinforced by the negative results of water testing by the method recommended by the U.S. Environmental Protection Agency (Rodgers et al 1999a, b).…”

“…Interestingly, studies on wild-collected oysters that utilized immunofluorescent antibody against both Cryptosporidium and Giardia never identified Giardia, whereas the load of Cryptosporidium was quite high (Fayer et al , 1999. Cryptosporidium and Giardia originate from similar sources and Giardia usually occurs in higher concentrations than Cryptosporidium in surface water (Atherholt et al 1998;Solo-Gabriele et al 1998). This may indicate that Giardia cysts do not resist digestion and disintegrate in the tissue of molluscan shellfish.…”