Papers by Joachim Richter
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2004
Schistosoma mansoni infection, associated morbidity and symptoms were studied in Piida fishing co... more Schistosoma mansoni infection, associated morbidity and symptoms were studied in Piida fishing community at Butiaba, along Lake Albert, Uganda, from November 1996 to January 1997. The study revealed that S. mansoni is highly endemic with an overall prevalence of 72%, a mean intensity of 419.4 eggs per gram (epg) faeces (geometric mean for positives only), with 37.8% of males and 33.0% of females excreting over 1000 epg. Prevalence and intensity peaked in the 10-14 year old age group and decreased with increasing age. Females were less heavily infected than males. Differences were also shown between tribes. Diarrhoea and abdominal pain were commonly reported in Piida. However, no clear-cut correlation between intensity of S. mansoni infection and these conditions could be demonstrated, indicating that retrospective questionnaires concerning S. mansoni related-symptomatology are of limited value. Organomegaly, as assessed by ultrasonography, was frequent and hepatomegaly was associated with heavy S. mansoni infection. No correlation was demonstrated between splenomegaly and infection. This study emphasizes that schistosomiasis mansoni is a major public health problem in Piida fishing community and presumably also in many similar fishing communities. These observations call for immediate intervention and can help in planning long-term strategies for sustainable morbidity control.
Chronic schistosomiasis mansoni is associated with impaired cell-mediated immune responsiveness (... more Chronic schistosomiasis mansoni is associated with impaired cell-mediated immune responsiveness (CMI). To assess co-stimulatory factors essential in the induction phase of CMI, interleukin 1 (IL-1) concentration was determined in the sera and cell culture supernatants of Schistosoma mansoni-infected patients, and circulating monocytes were phenotyped, labelling membrane IL-1 and HLA-DP. In addition, adherent cell oxidative-burst capacity was investigated. Since involvement of IL-1;? in the pathogenesis of severe granulomatous lesions could not be ruled out. 17 patients with intestinal schistosomiasis and 17 patients with hepatosplenic schistosomiasis were matched for intensity of infection and monitored 3-6 months after praziquantel therapy. Seventeen age-and sex-matched uninfected residents ofthe study area in Alagoas, Brazil, acted as controls. Whereas schistosomiasis patients and controls did not differ in the expression of monoeyte surface antigens and the capacity of adherent cells to generate H2O2, IL-1^ release by monocytes in vitro was significantly reduced in both intestinal and hepatosplenic patients. Low concentrations of circulating IL-1 ^ were detected in comparable frequencies in untreated patients and controls. Three months after therapy, IL-I^ was detectable in serum in an increased proportion of intestinal schistosomiasis patients. IL-1 release in vitro gradually increased in all patients and reached control values 6 months after therapy.
Emerging infectious diseases, 2002
We report the first case of Rickettsia felis infection in Europe to be documented by polymerase c... more We report the first case of Rickettsia felis infection in Europe to be documented by polymerase chain reaction (PCR) and serologic testing.
Parasitology Research, 2004
Co-reactivity of plasmodial histidine-rich protein 2 and aldolase on a combined immuno-chromograp... more Co-reactivity of plasmodial histidine-rich protein 2 and aldolase on a combined immuno-chromographic-malaria dipstick (ICT) as a potential semi-quantitative marker of high Plasmodium falciparum parasitaemia
Parasitology Research, 2004
The value of ultrasonography as an adjunct for diagnosis and monitoring malaria was investigated.... more The value of ultrasonography as an adjunct for diagnosis and monitoring malaria was investigated. In all, 118 patients (male/female 65/53; age 2-78 years, median 29 years) with malaria underwent a standardised abdominal ultrasound examination at baseline. In 62 out of 118 patients, ultrasonography was repeated 21 days later. In the results at baseline, huge splenomegaly with firm organ consistency, consistent with hyperreactive malarious splenomegaly syndrome, was observed in two Cameroonese children. In the other 116 patients, the most common finding was non-specific splenomegaly (96/116, 82.76%), occurring more frequently in nonimmune patients (71/78, 91.03%) than in patients who had grown up in malaria-endemic areas (25/38, 65.79%; P<0.002). No correlation was found between liver or spleen size and any clinical parameter. The results on day 21 show that, although splenomegaly after therapy persisted more frequently in patients with malaria recrudescence or relapse (8/8, 100%) than in patients cured (32/54, 59.26%; P<0.0421), the practical value of this finding is questionable. Ultrasonography cannot be regarded as a first-line diagnostic method in patients with malaria.
Journal of Clinical Ultrasound, 2008
Sonographers increasingly face imported diseases such as subcutaneous myiasis. In myiasis, some f... more Sonographers increasingly face imported diseases such as subcutaneous myiasis. In myiasis, some fly species such as the American Dermatobia hominis and the African Cordylobia anthropophaga use humans as intermediate hosts for the maturation of their larvae. High-resolution gray-scale and color Doppler sonography enabled us to identify D hominis larvae in 2 travelers to Central America by visualizing their typical shape, segmentations, and the continuous fluid transport inside the larval body cavity and spiracles. The small C anthropophaga larva in an individual returning from Namibia was initially not detected. Only when using color Doppler sonography was the larva discerned by its intralarval fluid transport. Sonography enables clinicians to locate viable subcutaneous larvae in suspected cases of myiasis.
Transactions of The Royal Society of Tropical Medicine and Hygiene, 1995
Memórias do Instituto …, 2001
A group of experts on schistosomiasis and ultrasonography discussed the experiences and results o... more A group of experts on schistosomiasis and ultrasonography discussed the experiences and results obtained with the Niamey-Belo Horizonte Protocol on Ultrasonography in Schistosomiasis. A series of recomendations about qualitative and quantitative data obtained by ultrasound in studies performed in Africa and Brazil are presented. Imunological, genetic and epidemiological studies must rely on ultrasound for the identification of patients with periportal thickening/fibrosis.
Parasitology Research, 2010
Relapsing human malaria is regarded to be caused by Plasmodium vivax and Plasmodium ovale. P. viv... more Relapsing human malaria is regarded to be caused by Plasmodium vivax and Plasmodium ovale. P. vivax relapses originate from dormant liver stages: “hypnozoites”. Also, P. ovale, a species considered as closely related to P. vivax, is in analogy assumed to display hypnozoites. A close biologic relationship is, however, not supported by molecular genetic studies. Therefore, original literature published since the description of P. ovale in 1922 was systematically screened for the demonstration of hypnozoites or circumstantial evidence for their existence, i.e. the occurrence of true relapses. In P. ovale infection, hypnozoites have never been demonstrated by biological experiments, and the few reports published on relapses have conflicting results.
Acta Tropica, 1996
Little is known whether and to what extent antiparasitic treatment cures female genital schistoso... more Little is known whether and to what extent antiparasitic treatment cures female genital schistosomiasis (FGS). Using a standard protocol, of twenty-one women with FGS nine were re-examined at two to nine weeks after they had been treated with praziquantel at a single dose of 40 mg/kg. Symptoms related to pathology of the urinary tract and to a lesser extent of genital pathology subsided in most patients. Schistosoma haematobium ova were no longer detectable in urine of any of the patients post-treatment. Efficiency of chemotherapy against adult worms was confirmed by the disappearance of circulating anodic antigen (CAA) in serum. Sandy patches showed resolution in two of four cases after chemotherapy. Papillomata due to schistosomiasis alone improved, but persisted in mixed infection with human papilloma virus (HPV) or when HPV was the only underlying cause. In one patient ulcera could not be related with certainty to schistosomiasis at admission, but resolved after treatment with praziquantel. Leukoplakia (two cases) was not influenced by chemotherapy, or even increased during follow-up, regardless of whether ova had been detected or not. Although the follow-up period was rather short, time intervals were not standardized, and a relatively small number of patients was investigated, it could be shown that genital pathology due to sequestered S. haematobium ova is, at least partially, reversible already two to nine weeks after killing the adult worms by praziquantel. This is paralleled by a normalization of inflammatory immune responses detectable in histological sections and vaginal lavage.
Acta Tropica, 1996
Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive t... more Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54
Acta Tropica, 1996
Schistosomiasis of the lower female reproductive tract manifests itself in a broad spectrum of cl... more Schistosomiasis of the lower female reproductive tract manifests itself in a broad spectrum of clinical features. However, clinical and histopathological findings have never been studied in a synoptic manner. Based on the assumption that any type of pathology present in the female reproductive tract is the expression of a complex pathophysiological reaction towards eggs sequestered in the genital tissues, we decided to analyze colposcopic and histopathological findings in a comprehensive manner. Thirty-three women in Malawi with urinary and genital schistosomiasis were examined parasitologically and gynecologically. A thorough colposcopic examination with photodocumentation was performed and biopsies were taken from the cervix, the vagina and/or the vulva for histological sectioning and immunohistochemistry. The predominant colposcopic findings were sandy patches on the cervical surface similar to those seen in the bladder and polypous/papillomatous tumors with irregular surface on the vaginal wall and in the vulvar area. The histopathological sections of sandy-patch-like lesions demonstrated only a small cellular reaction around S. haematobium eggs in various stages of disintegration. In contrast, in the case of polyps the histology revealed a more pronounced immunological reaction characterized by a heavy cellular infiltrate. One case of invasive squamous cell carcinoma of the cervix was diagnosed. We conclude that colposcopy is a useful tool in the detection of FGS related pathology in the lower female reproductive tract * Corresponding author.
Acta Tropica, 1996
A total of 51 women with urinary schistosomiasis haematobium were examined in order to identify d... more A total of 51 women with urinary schistosomiasis haematobium were examined in order to identify diagnostic indicators for female genital schistosomiasis (FGS). Patients were selected at random from the outpatient department of the Mangochi District Hospital, Malawi. The medical histories were recorded according to a pre-designed questionnaire and the women were subjected to a thorough gynaecological examination including colposcopy and photographic documentation of lesions. Microscopy of genital biopsies revealed that 33 of the 51 women had S. haematobium ova in cervix, vagina and/or vulva in addition to the presence of ova in urine. The most sensitive diagnostic procedure was bedside microscopic examination of a wet cervix biopsy crushed between two glass slides, which revealed 25 of the 33 genital infections. There was a significant correlation between the size of genital lesions and the number of ova counted per mm 2 of crushed tissue. Women with FGS had significantly more tumours in the vulva than women with schistosomiasis limited to the urinary tract. Most of the observed genital pathology could easily be identified by the naked eye, but colposcopic examination yielded valuable additional information like the demonstration of * Corresponding author. Fax +4722119181. neovascularisation around cervical sandy patches. Few of the symptoms previously regarded as indicators for FGS could be linked to the presence of schistosome ova in genital tissue. Husbands of infertile women with FGS had children with other women significantly more often than husbands of women who only had urinary schistosomiasis. This, together with the finding that the majority of the divorced women had FGS, indicates that the manifestation of this disease may have implications for the marital and sexual life of the affected women.
Acta Tropica, 1996
Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive t... more Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54
Acta Tropica, 1996
Hematuria, proteinuria and leukocyturia were semiquantitatively assessed by reagent strips in sin... more Hematuria, proteinuria and leukocyturia were semiquantitatively assessed by reagent strips in single morning urine of women of fertile age visiting the outpatient department of the Mangochi district hospital, Malawi. This was part of a diagnostic approach to female genital schistosomiasis (FGS). In 51 women ova of Schistosoma haematobium were detected in urine by a filtration technique. In 33 of these women ova were also present in genital tissue as demonstrated by microscopic examination of biopsies. In 209 women no ova were found in the single urine filtered. There were significantly higher scores for hematuria, proteinuria and leukocyturia as well as of the combined reagent strip index (RSI) in egg-excreting than in egg-negative women. The sensitivity of a single hematuria, proteinuria and leukocyturia reading was 98, 84 and 73%, respectively. However, the respective specificity was only 24, 22 and 23%. The best prediction of urinary schistosomiasis was achieved by a +2 score for hematuria, of which the sensitivity was 94% and the specificity was 61%. The high falsepositive rates can probably be explained by contamination of urine by vaginal secretion. Moreover, cases of schistosomiasis have probably been overlooked because only a single morning urine sample was examined. The total absence of hematuria, proteinuria and leukocyturia, however, may be used to rule out heavy infections in community surveys. There was no difference in reagent strip scores between women with genital and urinary schistosomiasis as compared with those with urinary tract lesions alone. Thus urine analysis reagent strip readings do not help to discriminate between S. haematobium infected women with and without FGS.
Acta Tropica, 2003
Infections with Schistosoma mansoni were identified in an area of Dhofar (Oman), where this paras... more Infections with Schistosoma mansoni were identified in an area of Dhofar (Oman), where this parasite had been virtually absent during recent years and was reported only very sporadically before 1992. In the present survey, performed late in 2001, between 1 and 13% of children (n = 519) were found to excrete eggs (one Kato-Katz-smear) in four schools, from four different villages, but no infections were detected in additional five schools (n = 281). Infections were light (<72 eggs/g of faeces) in 19 of the 36 children found infected. Serologic examination of sera (n = 511) was done by ELISA (based on soluble worm antigen) and immunofluorescence tests (IFT, based on cryostat sections of adult S. mansoni). The prevalence according to serological tests was between 3 and 43% in the four schools with infected children. Positive test results were taken to reflect active infections, since false positive reactions could largely be excluded. According to ultrasound (US) examinations performed on 96 individuals (children and adults) from the four villages, livers were normal in all except three cases of mild pathology, which could be assigned to schistosomiasis mansoni (pattern C, ages 32-40 years). All data suggest that transmission of S. mansoni has been re-introduced only recently in Dhofar and that this emergence of schistosomiasis is limited to at most a few foci.
Parasitology Research, 2015
The original article BThe WHO-ultrasonography protocol for assessing morbidity due to Schistosoma... more The original article BThe WHO-ultrasonography protocol for assessing morbidity due to Schistosoma haematobium. Acceptance and evolution over 14 years. Systematic reviewT he online version of the original article can be found at http://dx.
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Papers by Joachim Richter