Clinical and ultrasound findings before and after praziquantel treatment among Venezuelan schistosomiasis patients

Revista da Sociedade Brasileira de Medicina Tropical 40(5):505-511, set-out, 2007 ARTIGO-ARTICLE Clinical and ultrasound findings before and after praziquantel treatment among Venezuelan schistosomiasis patients Achados clínicos e no ultra-som pré e pós tratamento com praziquantel em pacientes venezuelanos com esquistossomose Raiza Ruiz-Guevara1, Belkisyolé Alarcón de Noya1, Sharon Kay Valero2, Pablo Lecuna2, Miguel Garassini2 and Oscar Noya1 ABSTRACT Abdominal ultrasound can be a useful tool for diagnosing periportal fibrosis related to Schistosoma mansoni infection, and also for planning and monitoring the evolution of hepatic morbidity following control measures. We evaluated the standardized ultrasound methodology proposed by the World Health Organization for detecting periportal fibrosis and portal hypertension, among patients from an endemic area in Venezuela, and the impact of praziquantel treatment 3-5 years later. After chemotherapy, complete reversal of periportal lesions was observed in 28.2% of the cases and progression of the disease in 5.1%. Improvement in the hepatic disease started with a reduction in the periportal thickening followed by a decrease in the size of the left hepatic lobe, spleen and mesenteric and spleen veins. Ultrasound confirmed the clinical findings after chemotherapy among the patients with reversal of the disease. However, in patients with more advanced disease, these findings were contradictory. There was no correlation between evolution of the disease seen on ultrasound and age, intensity of infection or serological findings. Key-words: Schistosoma mansoni. Ultrasound. Low transmission area. Venezuela. Praziquantel. RESUMO O ultra-som abdominal pode ser uma ferramenta útil para o diagnóstico da fibrose periportal relacionada à infecção por Schistosoma mansoni, e também para planejar e monitorar a evolução da morbidade hepática após medidas de controle. Nós avaliamos a metodologia padronizada no ultra-som, proposta pela Organização Mundial da Saúde, para a detecção da fibrose periportal e hipertensão porta, em pacientes de área endêmica da Venezuela e o impacto do tratamento com praziquantel 3-5 anos depois. Após quimioterapia, houve reversão completa das lesões periportais em 28,2% dos casos e progressão da patologia em 5,1%. A melhora da patologia hepática começou com a redução do espessamento periportal seguida pela diminuição do tamanho do lobo esquerdo, baço e veias mesentérica e esplênica. O ultra-som confirma os achados clínicos após quimioterapia em pacientes com reversão da patologia; contudo, naqueles com patologia mais avançada, estes achados foram contraditórios. Não houve correlação entre evolução da patologia ultra-sonográfica com idade, intensidade da infecção ou achados sorológicos. Palavras-chaves: Schistosoma mansoni. Ultra-som. Área de baixa transmissão. Venezuela. Praziquantel. Schistosomiasis is the main cause of periportal fibrosis worldwide34 and is responsible for the classic hepatointestinal clinical manifestations of chronic schistosomiasis. Abdominal ultrasound (US) is an alternative method for epidemiological fieldwork, because it is not an expensive or invasive method and provides immediate results3. In studies on periportal fibrosis, some authors have found that US is comparable with liver biopsy2 10 13 and angiography21, but not with fibrogenesis markers8 16 17. Since 1992, World Health Organization (WHO) experts and other investigators have proposed some standardized methods for defining the presence and degree of periportal fibrosis. US can be used to plan strategies for controlling schistosomiasis-related morbidity and monitoring its evolution after treatment. Anti-Schistosoma mansoni drugs allow partial or complete reversal of periportal 1. Cátedra de Parasitología, Instituto de Medicina Tropical, Universidad Central de Venezuela, Caracas, Venezuela. 2. Cátedra de Gastroenterologia. Escuela de Medicina Luis Razetti, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela. Financial support: The first part of the present work was supported by a grant obtained by the PCEE/PNUD (Project VEN/96/002) through a grant from FONACIT. The second part was financed by the “Agenda Salud” – FONACIT (Projects N° 2000001878 and 2005000199). Address to: Dra. Raiza Ruiz-Guevara. Cátedra de Parasitologia. Instituto de Medicina Tropical, Universidad Central de Venezuela, Los Chaguaramos, Caracas 1041-A, Apartado Postal 47706, Venezuela. Tel: 0058212605-3548/0058212605-3587; Fax: 0058212605-3563. e-mail: Recebido para publicação em: 24/02/2006 Aceito em: 19/09/2007 505 Ruiz-Guevara R et al fibrosis as assessed by US7 11 14 25. While the majority of these studies have been conducted in high or moderate transmission areas, information about areas of low endemicity is scarce. In this study, we evaluated periportal fibrosis in schistosomiasis cases using US before and after specific treatment, in one community of our low endemic transmission area in Venezuela. MATERIAL AND METHODS This work was carried out between 1998 and 2003 in Belén (Carabobo State) in the central-northern region of Venezuela. In this focus of schistosomiasis, large-scale control programs based on selective praziquantel (PZQ) chemotherapy, environmental measures, water supply measures, sanitation and snail control had been applied. However, in 1998-2000, we demonstrated that transmission had re-emerged, since we found infected Biomphalaria glabrata snails and prevalence of 12.6% using parasitological and serological criteria5. The parasitological diagnosis of schistosomiasis was made using the Kato-Katz method18. Before and after treatment, two Kato smears were prepared from one fecal sample. Based on the WHO criteria35, three categories of infection intensity (expressed as eggs per gram of feces) were considered: mild (1-100 eggs per gram of feces), moderate (101-400) and severe (>400). Venous blood was collected from each person and sera were stored at -80°C. The following serological tests were performed: enzyme-linked immunosorbent assay with soluble antigen of Schistosoma mansoni egg using sodium metaperiodate (ELISASEA-SMP)4, alkaline phosphatase immunoassay (APIA)24 and the circumoval precipitin test (COPT)31. Parasitological and immunological tests made it possible to allocate patients to one of three categories of schistosomiasis case5: Criterion I: people with Schistosoma mansoni eggs in stools, who usually had positive results from all the serological tests; Criterion II: people without Schistosoma mansoni eggs in stools, but with positive results from COPT and from one or both of the immunoassays, and without previous anti-schistosomal treatment over the last 12 months; and Criterion III: people without Schistosoma mansoni eggs in stools, with negative results from COPT and simultaneously positive results from both immunoassays, and without previous anti-schistosomal treatment. Physical examination of the liv (...truncated)