Clinical and laboratorial evaluation of urinary schistosomiasis in Brazilians after staying in Mozambique

We examined 87 Brazilian individuals of a group of 132 that, on July and November 1994, participated in a peace mission in Mozambique. They served in an endemic area for haematobic schistosomiasis, where they swum in Licungo river during leisure time. Their arithmetic mean age was 31 year and all of them were male. Their urine test showed that 30 (34.5%) eliminated S. haematobium eggs and 55 (63.2%) presented positive serology by the enzime-linked immunoelectrotransfer blot test with purified microsomal antigen of S. haematobium adult worms. Eosinophilia was found in 30 (34.5%), haematuria in 26 (29.9%), dysuria in 32 (36.8%) and lombar pain in 36 (41.4%). All of those that eliminated eggs through urine had positive serology. Among the 25 patients with positive serology and without S. haematobium eggs in the urine test, 13 were symptomatic and 12 assymptomatic. The treatment with praziquantel for the 30 patients, with urine positive to S. haematobium eggs, presented 70% of parasitological cure. Key-words: Schistosomiasis. Enzyme-linked immunoelectrotransfer blot assay. Brazilians. Mozambique. RESUMO Nós examinamos 87 brasileiros de um grupo de 132 que, entre julho e novembro de 1994, participaram de um missão de paz em Moçambique. Eles serviram em uma área endêmica de esquistossomose haematóbica e nadaram no rio Licungo em períodos de lazer. A idade aritmética deles era 31 anos e todos eram do gênero masculino. O exame de urina revelou que 30 (34,5%) eliminavam ovos de S. haematobium e 55 (63,2%) tinham sorologia positiva pelo teste enzyme-linked immunoelectrotransfer blot com antígeno microsomal purificado de vermes adultos de S. haematobium. Eosinofilia foi encontrada em 30 (34,5%), haematuria em 26(29,9%), disúria em 32(36,8%) e dor lombar em 36(41,4%). Todos que eliminavam ovos pela urina tiveram sorologia positiva. Entre os 25 pacientes com sorologia positiva e sem ovos de S. haematobium no exame de urina, 13 eram sintomáticos e 12 assintomáticos. O tratamento pelo Prazinquantel nos 30 pacientes com urina positiva para ovos de S. haematobium apresentou 70% de cura parasitológica. Palavras-chaves: Esquistossomose. Enzyme-linked immunoelectrotransfer blot assay. Brasileiros. Moçambique. 1. Seção de Vigilância Epidemiológica da Divisão de Ensino e Pesquisa do Instituto de Biologia do Exército, Rio de Janeiro, RJ. 2. Divisão de Parasitologia do Centro de Controle e Prevenção de Doenças, Atlanta, USA. 3. Laboratório de Biologia e Controle de Esquistossomose do Departamento de Medicina Tropical do Instituto Oswaldo Cruz da Fundação do Instituto Oswaldo Cruz, Rio de Janeiro, RJ. 4. Hospital Universitário Clementino Fraga Filho, Rio de Janeiro, RJ, Brasil. Address to: Dr. Iran Mendonça da Silva. Seção de Vigilância Epidemiológica/IBEx. R. Francisco Manuel 102, Benfica, 20911-270 Rio de Janeiro, RJ. Brasil. Tel: 55 21 3860-0442 ramal: 228; Fax: 55 21 3890-2135 ramal 200. e-mail: silva.iran@.ig.com.br Recebido em 04/03/04 Aceito em 13/04/06 The habitat of S. haematobium is the urinary tract where the host response to the eggs retained in the tissues results in lesions and hematuria. Urinary schistosomiasis is found in 53 countries on the African continent and in the Middle East ; however, no autochthonous case has been reported in Brazil thus far. A number of the 132 Brazilian military and ex-military servicemen, who served 4 months in Mozambique (Africa) on a United Nations peace mission in 1994 and had swum in the Licungo River, Zambezia province, during their leisure time, were infected with Schistosoma haematobium. The enzyme-linked immunoelectrotransfer blot assay (EITB)

The habitat of S. haematobium is the urinary tract where the host response to the eggs retained in the tissues results in lesions and hematuria.
Urinary schistosomiasis is found in 53 countries on the African continent and in the Middle East 33 34 ; however, no autochthonous case has been reported in Brazil thus far.A number of the 132 Brazilian military and ex-military servicemen, who served 4 months in Mozambique (Africa) on a United Nations peace mission in 1994 and had swum in the Licungo River, Zambezia province, during their leisure time, were infected with Schistosoma haematobium.The enzyme-linked immunoelectrotransfer blot assay (EITB) with purified antigens 25 has been used for the diagnosis of several infectious diseases.EITB has been important in elucidating epidemiological information in neurocysticercosis and schistosomiasis 1 4 5 8 15 17 19 22 29 .EITB was used to solve problems with cross reactivity in the serological diagnosis of parasitic infections, aiding in the selection of specific diagnostic antigens 3 10 18 20 23 25 26 27 ; in the evaluation of immunodiagnostic techniques for various infectious diseases 2 5 8 9 11 13 15 21 24 35 and in acquired immunity studies after the use of specific antigens 11 .EITB can be highly specific and sensitive in the detection of antibodies for many infectious agents 7 14 31 33 .
The aim of this study was to evaluate the signs and symptoms, laboratorial exams and clinical usefulness of EITB serology for the identification of Schistosoma haematobium infections in Brazilian returnees after exposure in Mozambique.

PATIENTS AND METHODS
The protocol of this study was approved by the Research Ethics Committee of the Army Biology Institute (Instituto de Biologia do Exército), Rio de Janeiro.Informed consent was obtained from all patients and the guidelines for human experimentation of the National Health Council were followed in the conduct of clinical research.Among the 132 Brazilian men who participated in a United Nations Peace Mission in Mozambique, Africa, 87 accepted our offer of clinical and serological evaluation for schistosomiasis.The principal signs and symptoms were evaluated together with laboratory exams.Three 24-hour urine samples were collected at a minimum interval of one week from all patients.Helminth eggs were recovered by sedimentation (24hr) and centrifugation (3,500g/5 min) of the urine sample.One-hundred µL of the centrifuged material was examined with a microscope at 100X and 400X magnifications.EITB assay, with purified adult worm microsomal antigens from S. haematobium (HAMA) or S. mansoni (MAMA), was performed as previously described 27 32 .
The patients avoiding S. haematobium eggs by urine were treated by praziquantel in a single dose (40mg/kg body weight) by oral route.The parasitological control of cure was done by urine, cystoscopy and histopathology.

RESULTS
The arithmetic mean age of the 87 patients was 31 (median = 32.02)years old.
In the follow up of 30 patients with S. haematobium eggs in urine exams, treated by praziquantel, 21 presented parasitological cure by urine exams and cystoscopy, biopsy and histopathological examination.Nine patients continued with viable eggs in the cystoscopy examination, in spite of negative urine examination.After the second treatment, five became negative for cystoscopy, one positive and the last three without information.

DISCUSSION
According our findings, signs and symptoms, S. haematobium eggs in the urine and eosinophilia, each one of them were frequent in about a third of the patients and the EITB assay positive in two third of them; the serology was twice most sensitive than urine examination.Other authors reported to be three times more sensitive in detecting S. haematobium infection 7 .The presence of eggs in urina confirm the infection.It is considered the golden standard of the diagnosis and indicate the specific treatment.
The EITB positive in all our cases with S. haematobium eggs in urine enhances the intrinsic value of this serological method.Otherwise 25 individuals who were negative for the urine examination had positive serology, and among them 12 without symptomatology.That 12 positive patients would not have been identified without EITB.Considering the frequent lacks of symptoms, we deem the EITB an important adjunct to patient identification for schistosomiasis, when its realization is possible.
Hematuria, dysuria, lumbar pain, eosinophilia are good indicators of infection, when the individuals come from endemic areas, as happened with some of our patients.

Table 1 -Clinical and laboratorial evaluation in the 87 individuals after exposure to Schistosoma haematobium infection in Licungo River (Mozambique -Africa).
Enzyme linked immunoelectrotransfer blot.HAMA: Antigen from Schistosoma haematobium.