Seasonal Distribution of Enteric Opportunistic Cryptosporidium Spp. Oocysts and Giardia Spp. Cysts in a Tropical Water Basin, Cameroon
Ajeagah, GA 1,*; Njine, T1; Bilong Bilong, CF1; Foto, SM1; Wouafo Ndayo Marguerite2;
Nola Moise1; Di Giovanni, GD3; Huw, S4
1 Laboratory of General Biology, P.O. Box 812, University of Yaondé, Cameroon
2 Centre Pasteur du Cameroun, BP 1274, Yaondé, Cameroon
3 Associate Professor, Environmental Microbiology & Waterborne Pathogens, Texas A&M University, Texas, USA
4 Drinking Water Inspectorate, Glasgow, UK
* Correspondence: ajeagahg@yahoo.com
Key Words: seasonality, transmission, Cryptosporidium spp. oocysts, Giardia spp. cysts, surface water
Received: 27 October, 2009; revised 12 January 2010; accepted 7 February; published 19 March 2010; available online 19 March 2010
Summary
The susceptibility of the human host to Cryptosporidium spp. and Giardia spp. (oo) cystic load is due to the immunodepression of the human host, the enteropathogenic transmission, the zoonotic potentialities of the parasites, and the mechanisms of environmental favoritism that influences the contact of these organisms with the host. Seasonal variables were taken into consideration in the determination of the qualitative and quantitative contamination of the Mfoundi River Basin in Yaounde by these parasites. The (oo) cysts were isolated and identified by the Ziehl Neelsen, iodine coloration method and the USEPA Method 1623.The seasonal bio-dynamics of Cryptosporidium oocysts in the streams analyzed indicate that, on average, the highest seasonal values were presented in Abiergue West (110.8 ± 61.33 oocysts/L), followed by Olezoa (88.24 ± 40.32 oocysts/L), Abiergue East (61.73 ± 43.28 oocysts/L), Biyeme (47.28 ± 19.54 oocysts/L), Mingoa (43.13 ± 31.38 oocysts/L) and Ekozoa (26.05 ± 15.15 oocysts/L). The lowest values were assessed in the long rainy season for Abiergue East, Biy eme, Olezoa, Ekozoa and the short dry season for Abiergue West and Mingoa. The highest values were determined in the long dry season for all the streams assessed. The statistical test revealed significant variations of this parameter between the seasons and the sampling sites (P < 0.05). In all the streams sampled, there was a decrease in oocysts density from the long dry season to the short rainy season. The seasonal bio-dynamics of Giardia cysts isolated and identified in the various streams reveal that the highest values were registered in Abiergue West (15.23 ± 7.25 cysts/L), followed by Mingoa (15.04 ± 10.63 cysts/L), Olezoa (13.93 ± 9.82 cysts/L), Abiergue East (12.83 ± 7.0 cysts/L), Biyeme (9.55 ± 4.02 cysts/L), and Ekozoa (8.05 ± 2.04 cysts/L). The variations of the cystic load were significant between seasons (P < 0.05) and not significant between the sampling sites (P > 0.05). From the seasonal point of view, the concentration of the cystic load seemed to decrease with an increase in precipitation, possibly due to the effect of dilution, as the rainfall diluted the concentration of the pathogens in the environment.
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