A study of the urban malaria transmission problem in Khartoum.

A study of malaria prevalence and transmission was carried out in Khartoum, the capital of Sudan. The sentinel sites were El manshia, an urban area on the Blue Nile and Ed dekheinat, a lower-income peri-urban area bordering the White Nile. Anopheles arabiensis, the only malaria vector encountered, was present throughout the year although vector density varied seasonally. Plasmodium falciparum was the only species found in El manshia. In Ed dekheinat P. falciparum, Plasmodium ovale and Plasmodium vivax constituted 84.9, 8.2 and 6.9% of the cases, respectively. Plasmodium ovale appears to have recently spread into Khartoum since it has not previously been reported there. We conclude that focal transmission of malaria in the districts bordering both Niles has become established and that the reservoir of human infections has increased in recent years leading to increased risk of malaria epidemics, particularly in the aftermath of seasonal flooding.

Mixed Schistosoma haematobium and S. mansoni infection: effect of different treatments on the serum level of circulating anodic antigen (CAA).

In this study, levels of circulating anodic antigen (CAA) in serum were investigated after differential treatment of 160 Sudanese patients with mixed Schistosoma haematobium and S. mansoni infections. The patients were randomly divided into four groups, which were treated with metrifonate (two doses of 10 mg/kg bodyweight), oxamniquine (60 mg/kg), praziquantel (40 mg/kg), or a multivitamin preparation, respectively. Serum, stool and urine samples were taken prior to treatment as well as one month and five months after chemotherapy. Before chemotherapy CAA levels were similar in the four groups. Antigenemia remained unchanged in the control group. In patients treated with praziquantel or oxamniquine the concentration of CAA decreased to a similar extent. However, whereas in the praziquantel group absence of CAA was already observed one month after treatment, clearing of CAA from the circulation seemed to take longer in patients treated with oxamniquine. Treatment with metrifonate did not result in a reduction of the CAA titres.

Diagnosis of pathologically confirmed Symmers' periportal fibrosis by ultrasonography: a prospective blinded study.

Symmers' periportal fibrosis of the liver is the major cause of morbidity and mortality in Schistosoma mansoni infection. The diagnosis is best established definitively by a wedge biopsy of the liver. The ability of abdominal ultrasonography to diagnose this condition was prospectively compared with two independent pathological examinations of wedge biopsies of the liver. Both pathologists and the ultrasonographer were unaware of the clinical diagnosis and each other's findings. Twenty-eight of 41 patients had Symmers' fibrosis by pathological examination and all were diagnosed correctly by ultrasonography prior to surgery. Symmers' fibrosis was not diagnosed by ultrasound in any of 10 patients without Symmers' fibrosis on biopsy. In 3 patients the diagnosis of Symmers' fibrosis was uncertain because the pathologists disagreed as to its presence. These results confirm the findings of previous studies and establish that ultrasonography is at least as sensitive as wedge biopsy in diagnosing Symmers' fibrosis.

Detection and quantification of circulating antigen in schistosomiasis by monoclonal antibody. II. The quantification of circulating antigens in human schistosomiasis mansoni and haematobium: relationship to intensity of infection and disease status.

Circulating cathodic and circulating anodic antigens were quantified in sera of patients infected with S. mansoni, S. haematobium or both parasites. A monoclonal antibody and a polyclonal antiserum were applied in precipitation and solid phase immunosorbent techniques using radio- and enzyme-labelled antibody as a tracer to detect the cathodic and anodic antigen respectively. The results show that circulating cathodic antigen can frequently be detected in an immunoprecipitation or an immunoradiometric assay in serum of infected patients. The serum concentration of this antigen was found to be significantly correlated to the number of S. mansoni worms and to be higher in patients with the hepatosplenic form of the disease than in those without such complications. Examining paired serum samples before and after specific treatment the determination of this antigen by monoclonal antibody reliably indicated efficacy of chemotherapy in patients having received different forms of treatment.

Intermittent chemotherapy with trichlorfon (metrifonate) reverses proteinuria, hematuria, and leukocyturia in urinary schistosomiasis: results of a three-year field study.

Trichlorfon (metrifonate) was given intermittently to 37 schoolboys with urinary schistosomiasis living in a hyperendemic area of the Sudan. Patients were followed up for three years. Initially, 10 mg of trichlorfon/kg of body weight was administered; this dosage was repeated 14 days and 16 months later. Patients still excreting eggs after 24 months received a fourth dose. At month 24, 61% and at month 36, 56% of the patients had no detectable egg excretion; the others showed severe reduction of egg output. The number of ova excreted was always paralleled by a combined scale of hematuria, leukocyturia , and proteinuria, as assessed by urine analysis reagent strips. Quantitative urine analysis at month 36 revealed pathological findings in only eight individuals. Thus, trichlorfon given three or four times in a dose of 10 mg/kg of body weight spaced over a period of two years was highly effective in reducing parasite load and disease in children living under hyperendemic conditions.

Fetal immune response following maternal diphtheria during early pregnancy.

A pregnant Sudanese woman contracted pharyngeal diphtheria during the first trimester of gestation. She had a severe diphtheritic toxaemia and paralysis of all four limbs but made a full recovery from these manifestations. Pregnancy, apart from vaginal bleeding, was not interrupted. At term she was delivered of a female baby who was physically normal but had a very high level of IgA in cord blood. Diphtheria in adults is a rare disease and the occurrence of diphtheria in a pregnant woman has not, as yet, been reported. Accordingly it is not known how fetal growth and development progress in the presence of diphtheria toxin in the maternal circulation. Similarly the effects on fetal immune responses of an acute maternal infection like diphtheria occurring in early pregnancy are not known.