Validation of Multiple Diagnostic Techniques to Detect Cryptosporidium sp. and Giardia sp. in Free-Ranging Western Lowland Gorillas (Gorilla gorilla gorilla) and Observations on the Prevalence of these Protozoan Infections in Two Populations in Gabon

Abstract

Anthropozoonotic diseases threaten the survival of western lowland gorillas (Gorilla gorilla gorilla). Use of accurate diagnostic techniques in gorilla health monitoring contributes to the conservation of gorillas by providing robust information for appropriate management decisions. To identify suitable protozoa diagnostic techniques for wild gorillas, 95 fecal specimens were collected in Lopé National Park and east of Moukalaba-Doudou National Park in Gabon, areas with high and low levels of human activity, respectively. The samples were examined for Cryptosporidium sp. and Giardia sp. by using the following diagnostic techniques: a commercially available immunofluorescent antibody test kit, Merifluor, and a rapid immune-assay, ImmunoCard STAT!, to detect Cryptosporidium sp. and Giardia sp., and a modified Ziehl-Neelsen stain to detect Cryptosporidium sp. oocysts. The results obtained from the Merifluor test, considered the "gold standard" in human studies, were used to estimate the prevalence of Cryptosporidium sp. and Giardia sp. infections in Lopé National Park (19.0% and 22.6%, respectively) and east of Moukalaba-Doudou National Park (0% and 9.1%, respectively). The difference in prevalence in both areas may be associated with differing levels of anthropogenic disturbance. The sensitivity and specificity of the latter two diagnostic techniques were calculated by using the Merifluor test as a control. The ImmunoCard STAT! was found suitable for Giardia sp. antigen detection (specific but not sensitive) and inappropriate for Cryptosporidium sp. antigen detection (not specific or sensitive). The modified Ziehl-Neelsen stain was found to be highly specific but not sensitive in the detection of Cryptosporidium sp. oocysts. These results underline the necessity of using ancillary tests and concentration methods to correctly identify positive samples. This is the first report of Cryptosporidium sp. and Giardia sp. infections in free-ranging western lowland gorillas and highlights the importance of verifying the accuracy of diagnostic techniques developed for human use before applying these to non-human primates.

Long-Term Monitoring of Microsporidia, Cryptosporidium and Giardia Infections in Western Lowland Gorillas (Gorilla gorilla gorilla) at Different Stages of Habituation in Dzanga Sangha Protected Areas, Central African Republic

“…Most of the other studies concerned with cryptosporidia in great apes and even in other primates did not discriminate species/genotypes [31], [43], [44], [73]–[75]. In the present study we detected only one C. bovis isolate originating from a habituated gorilla.…”

Low sensitivity of the ImmunocardSTAT® Crypto/Giardia Rapid Assay test for the detection of Giardia and Cryptosporidium in fecal samples from children living in Libreville, Central Africa

“…The existence of this reservoir therefore constitutes a potential risk for the infection of malnourished and immunocompromised individuals. The overall sensitivity of the ImmunoCardSTAT Ò test was 65.3 % for the detection of G. duodenalis, greater than that observed in Germany (58.0 %), Turkey (33.3 %) and in a study on gorillas in Gabon (57.9 %) (Oster et al 2006;Bayramoglu et al 2013;VanZijllLanghout et al 2010). A higher value (68.0 %) was reported by one study in USA (Agnamey et al 2011).…”

Prevalence of Cryptosporidium spp., Enterocytozoon bieneusi, Encephalitozoon spp. and Giardia intestinalis in Wild, Semi-Wild and Captive Orangutans (Pongo abelii and Pongo pygmaeus) on Sumatra and Borneo, Indonesia

“…Although there have been many reports of Cryptosporidium spp. in non-human primates [ 11 , 14 , 53 , 62 – 74 ], few have provided detailed molecular information about these parasites in the great apes [ 9 – 12 , 75 ]. Paralogous copies of the C .…”

“…Likewise, Cryptosporidium spp. was identified in African great apes in several studies [ 9 , 10 , 12 – 14 ]. Although Giardia intestinalis was previously detected in both Bornean and Sumatran orangutans [ 15 , 16 ], there remains a lack of detailed studies on microsporidia and Cryptosporidium spp.…”