[Bertiella mucronata] [Bertiella studeri]
Members of the genus Bertiella are cestodes (tapeworms) of non-human primates in nature. Human infections are uncommon . B. studeri and B. mucronata have been identified in children with some contact or association with non-human primates; a few cases may have been related to contaminated fruits. There has been some suggestion that B. studeri is a species complex based on reported morphological variance among human cases.
Although the life cycles of Bertiella species are not completely understood, it is generally believed the genus undergoes a two-host life cycle, with an arthropod intermediate host (usually a mite) and a vertebrate definitive host (usually non-human primates for the species implicated in human infection). Eggs and proglottids are passed in the feces of the definitive host . Oncospheres are ingested by the arthropod intermediate host . In the arthropod intermediate host, the oncospheres develop into cysticercoids . The definitive hosts become infected after ingesting arthropod intermediate hosts infected with cysticercoids. The cysticercoid everts an unarmed scolex , which it uses to attach to the small intestinal wall. Adults remain in the small intestine of the host . Although rare, humans may also serve as incidental definitive hosts for Bertiella spp., usually after accidentally ingesting infected mites .
Bertiella studeri usually infects monkeys in the genera Anthropopithecus, Cercopithecus, Cynomologus and Macaca; B. mucronata has been recovered from monkeys in the genera Callicebus and Alouatta. Apes such as chimpanzees (Pan spp.) may also be infected, often in captive settings. Intermediate hosts are believed to be one or several species of orobatid mites.
Bertiella mucronata is a New World species known to occur in South America and Cuba; B. studeri is an Old World species found in Africa and Asia. Imported cases have been recorded in non-endemic areas. Most human cases of bertiellosis occur in persons who have had contact with primates.
With so few human cases reported, clinical aspects of this infection are not well defined. Many of the reported cases have been asymptomatic; however, some patients have reported gastrointestinal symptoms.
Eggs of Bertiella spp.
Proglottids and scoleces of Bertiella spp.
Diagnosis is made by the finding of proglottids or, less commonly, eggs in stool. The eggs are characteristic and can be liberated from gravid proglottids.
Standard laboratory precautions for the processing of stool samples apply. Eggs of Bertiella spp. are not infectious to humans.
Sun, X., Fang, Q., Chen, X.Z., Hu, S.F., Xia, H. and Wang, X.M., 2006. Bertiella studeri infection, China. Emerging Infectious Diseases, 12(1), p.176.
Bhagwant, S., 2004. Human Bertiella studeri (family Anoplocephalidae) infection of probable Southeast Asian origin in Mauritian children and an adult. The American journal of tropical medicine and hygiene, 70 (2), pp.225–228.
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