Epidemiological, clinical and laboratory studies on parasitic infections as a cause of fever of undetermined origin in Dakahlia Governorate, Egypt.

Forty-three patients who fulfilled the international criteria for prolonged fever were exposed to thorough history taking, clinical and laboratory investigations. The latter included urine and stool examination, urine and blood culture, haemogram, liver and renal function tests, chest X-ray, tuberculin test, bone marrow, liver biopsy, blood films, serological tests including ELISA, IHA and IFA for detection of schistosomiasis, toxoplasmosis and malaria. Parasitic infections were detected in 30/43 (69.7%), 55.8% of whom had pure parasitic infection and 14% had in addition other causes. The majority of cases with positive etiology were coming from rural areas. The pattern of fever was predominantly intermittent especially with malaria and schistosomal cases. Fever of 21-41 days duration was noted in 70% of patients and 23.3% lasted up to more than 56 days. Visceromegaly (hepatomegaly and/or splenomegaly) was observed in all patients except one case. Lymphadenopathy was detected in ten cases, six of whom were visceral leishmaniasis. The IHA test for leishmaniasis detected ten cases at titres of 256, 512 and 1024 reciprocally. The dot-ELISA gave seropositivity in only 8/10 cases diagnosed by IHA test. So eight cases of VL were diagnosed by two serological tests at high titres. The detection of seropositive cases of visceral leishmaniasis in the studied area, suggests a focus or foci and warrants epidemiological study to establish the actual situation. Generally speaking, parasitic aetiology should be in mind in any case of FUO in Dakahlia. Serological tests are valuable, simple and safe tools for conforming the diagnosis of schistosomiasis, leishmaniasis, toxoplasmosis and malaria.

Immunogenetic susceptibility for post-schistosomal hepatic fibrosis.

In 19 children with hepatic fibrosis as the result of continued schistosomiasis mansoni and 20 children without hepatic fibrosis, the following studies were carried out: HLA antigen typing for 30 antigens, immune response of T lymphocytes to schistosome antigen by measuring DNA synthesis evidenced by 3H-thymidine uptake, and measurement of total OKT3+, OKT4+, and OKT8+ cells using monoclonal antibodies. Patients with hepatic fibrosis were mostly high responders in contrast with those without fibrosis. High immune response and susceptibility to post-schistosomal hepatic fibrosis were associated with a high frequency of A2 and B12 antigens and a lack of DR2 antigens, while low response was associated with the presence of the DR2 antigen. The T4+:T8+ ratio showed increased suppressor proportions in patients with low immune response and/or with no hepatic fibrosis. We suggest an immunogenetic susceptibility for post-schistosomal hepatic fibrosis, probably controlled by HLA-linked genes via the suppressor T cells.