1º Autor: Sílvia Gomes
Serviço de Microbiologia, Clínica de Genética e Patologia, ULS Santo António
Coautores: Paula Martins da Costa; Ana Paula Castro, Serviço de Microbiologia, Clínica de Genética e Patologia, ULS Santo António
Introdução: Migration of people and animals can increase exposure to unfamiliar pathogens, creating health risks for migrants and resident populations. Intestinal parasites, transmitted through contaminated soil, food or water, may remain asymptomatic or cause significant morbidity, representing an important public health concern. Migrants, particularly those from refugee or displacement settings, may carry parasites such as Schistosoma sp., Ascaris lumbricoides or Trichuris trichiura, capable of producing substantial illness. We report three cases of schistosomiasis, trichuriasis and A. lumbricoides. Schistosomiasis is not endemic in the European Union; however, cases continue to be identified among migrants and travelers returning from endemic regions. According to the World Health Organization, Schistosoma intercalatum occurs in the rainforests of Central Africa, whereas T. trichiura and A. lumbricoides are globally distributed, with higher prevalence in tropical areas and settings of poor sanitation.
Case Reports
Case 1: A 21-year-old female, originally from São Tomé e Príncipe and residing in Portugal for the preceding 3 months, was admitted with acute hepatitis B. During hospitalization, serologic analysis demonstrated the presence of antischistosomal antibodies. Subsequent parasitological examination of stool specimens by light microscopy identified ova of S. intercalatum and T. trichiura. Anthelmintic therapy with praziquantel and albendazole was administered. On follow-up evaluation, parasitological studies were negative for both helminths.
Case 2: A 16-year-old female, originally from São Tomé e Príncipe and residing in Portugal for the past year, was referred to the hospital outpatient clinic with a presumptive diagnosis of schistosomiasis. She reported abdominal pain as well as difficulty initiating micturition. Parasitological examination of stool specimens by light microscopy revealed ova of S. intercalatum. The patient did not attend the scheduled follow-up appointment for reevaluation.
Case 3: Two male siblings, aged 9 and 13 years, originally from São Tomé e Príncipe and residing in Portugal for the past year, were referred to the hospital outpatient clinic following confirmation of parasitic infection in their sister with G. lamblia and T. trichiura. Parasitological examination of stool specimens from both brothers, by light microscopy, demonstrated the presence of T. trichiura and A. lumbricoides ova and G. lamblia cysts. Molecular analysis using polymerase chain reaction (PCR) detected nucleic acids of G. lamblia, T. trichiura, and Ascaris sp. The entire family was treated with albendazole, ivermectin, and metronidazole. On follow-up evaluation, parasitological testing revealed that one of the brothers remained positive for G. lamblia.
Discussion and Conclusion: People migrating and traveling from endemic areas can introduce these parasitoses into new areas leading to the spreading and infection of local populations. Healthcare professionals in receiving countries may lack sufficient knowledge about parasites common in migrants’ countries of origin, making diagnosis challenging. PCR assays are now commercially available, often as part of a multiplex panel for organism detection in stool samples. PCR is not available for all intestinal parasites and is of limited use following treatment of parasitoses as residual detection might represent killed or non-viable parasites. Microscopy remains a “gold standard” for diagnosing many parasitic infections, particularly when a less common parasite, such as S. intercalatum, is suspected.