The presence of a cytopathologist increases the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration cytology for pancreatic adenocarcinoma: a meta-analysis.

OBJECTIVE: A meta-analysis has not been previously performed to evaluate critically the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solely pancreatic ductal adenocarcinoma and address factors that have an impact on variability of accuracy. The aim of this study was to determine whether the presence of a cytopathologist, variability of the reference standard and other sources of heterogeneity significantly impacts diagnostic accuracy. METHODS: We conducted a comprehensive search to identify studies, in which the pooled sensitivity, specificity, likelihood ratios for a positive or negative test (LR+, LR-) and summary receiver-operating curves (SROC) could be determined for EUS-FNA of the pancreas for ductal adenocarcinoma using clinical follow-up, and/or surgical biopsy or excision as the reference standard. RESULTS: We included 34 distinct studies (3644 patients) in which EUS-FNA for a solid pancreatic mass was evaluated. The pooled sensitivity and specificity for EUS-FNA for pancreatic ductal adenocarcinoma was 88.6% [95% confidence interval (CI): 87.2-89.9] and 99.3% (95% CI: 98.7-99.7), respectively. The LR+ and LR- were 33.46 (95% CI: 20.76-53.91) and 0.11 (95% CI: 0.08-0.16), respectively. The meta-regression model showed rapid on-site evaluation (ROSE) (P = 0.001) remained a significant determinant of EUS-FNA accuracy after correcting for study population number and reference standard. CONCLUSION: EUS-FNA is an effective modality for diagnosing pancreatic ductal adencarcinoma in solid pancreatic lesions, with an increased diagnostic accuracy when using on-site cytopathology evaluation.

Cumulative sum procedure in evaluation of EUS-guided FNA cytology: the learning curve and diagnostic performance beyond sensitivity and specificity.

BACKGROUND: Using cumulative sum (CUSUM) chart, we address two questions: (i) Over time, how will an EUS-FNA (endoscopic ultrasound guided fine needle aspiration) service maintain an acceptable non-diagnostic rate defined as technical failures, unsatisfactory specimens and atypical and suspicious diagnoses? (ii) Over time, how will EUS-FNA maintain acceptable diagnostic errors (false-positives plus false-negative diagnosis)? METHODS: The study included all consecutive patients who underwent EUS-FNA at our institution from July 2000 to October 2003 and were followed up until December 2004. Using a simple spread sheet, we designed CUSUM charts and used them to track trends and assess performance at a preset acceptable rate of 10% and a preset unacceptable rate of 15% for non-diagnostic rate and diagnostic errors. We assessed all cases collectively and then in groups defined by site, size and cytopathologist. RESULTS: Of 876 patients undergoing EUS-FNA, 83 (9.5%) had non-diagnostic results: 43 (51%) of these diagnoses were 'atypical', 27(33%) were 'suspicious for malignancy', eight (10%) were 'insufficient material for diagnosis' and five (6%) were 'technical failure'. In 585 cases with adequate follow up, there were 26 (6.3%) diagnostic errors: three (0.5%) were false positive and 23 (3.1) were false negative. The overall CUSUM charts for both non-diagnostic rate and for diagnostic error rate start with a small period of learning then cross to a significantly acceptable level at case numbers 121 and 97 respectively. Our diagnostic performance was better in lymph nodes than in the pancreas and other organs and was not significantly different for lesions 25 mm in diameter. Performance was better for pathologists with prior experience than for pathologists without experience. CONCLUSION: In the current climate of proficiency testing, error tracking and competence evaluation, there is a great potential for the use of CUSUM charts to assess procedure failure and error tracking in quality control programs, particularly when a new procedure such as EUS-FNA is introduced in the laboratory. Additionally, the method can be used to assess trainee competency and to track the proficiency of practicing cytologists.

Malignant pleural effusions due to small-cell lung carcinoma: a cytologic and immunocytochemical study.

Patients with small-cell lung carcinoma (SCLC) rarely present with pleural effusions. Based on morphology alone, recognition of SCLC in effusion cytology may be challenging because of the resemblance of neoplastic cells to lymphocytes. Immunocytochemistry may be helpful in its diagnosis. The objective of this study was to review the morphology and evaluate the use of immunocytochemistry in diagnosing SCLC in pleural fluids. Patients with SCLC who presented with pleural effusions were identified during a 6-yr period. The cytology and medical records were reviewed. Formalin-fixed, paraffin-embedded cell blocks of fluid specimens were immunostained with neuroendocrine markers (chromogranin A and synatophysin), cytokeratin 20 (CK20), and thyroid transcription factor-1 (TTF-1). The latter is a nuclear transcription protein that is expressed in normal respiratory epithelium and also in more than 90% of SCLCs. Of the 256 patients diagnosed with SCLC during the study period, 8 (2.7%) patients (3 females and 4 males, age range from 56-85 yr) also developed pleural effusions. One patient had 2 fluid specimens during the course of their disease, giving a total of 9 specimens. Four specimens had a positive cytologic diagnosis of SCLC, and 2 were initially diagnosed as suspicious for SCLC. The remaining 3 specimens were negative for SCLS. The specimens with a positive or suspicious diagnosis showed single and aggregates of small to medium-sized single cells with a high nuclear:cytoplasmic (N:C) ratio, round to angulated nuclei, and salt-and-pepper chromatin. Nuclear molding was also noted. Five out of 6 (83%) specimens with a positive or suspicious diagnosis of SCLC were positive for both chromogranin A and TTF-1. Synaptophysin was positive in 3 of 6 (50%) positive or suspicious cases. None of the cases were positive for CK20. All cases with a negative cytologic diagnosis were negative for chromogranin A, synatophysin, CK20, and TTF-1. In conclusion, patients with SCLC rarely present with pleural effusions. The cytology of SCLC is characteristic. The use of immunocytochemistry, particularly with antibodies to chromogranin A, TTF-1, and CK 20, aids in the differential diagnosis.

Sex steroid receptor regulation by genistein in the prepubertal rat uterus.

We evaluated the mechanism of action by the phytoestrogen genistein in the prepubertal rat uterus, when administered pharmacologically or physiologically. Female rats were injected with genistein (500 microg/g body weight), estradiol benzoate (EB) (500 ng/g body weight) or vehicle, dimethylsulfoxide (DMSO), on days 16, 18, and 20 postnatal. In 21-day-old rats, both compounds increased circulating estradiol and decreased progesterone concentrations. Uterine estrogen receptor alpha (ER-alpha) and androgen receptor (AR) proteins were reduced, and progesterone receptors (PR) were increased, as measured by western blot analyses. Immunohistochemistry for ER-alpha was confirmatory. Reverse transcription-polymerase chain reaction (RT-PCR) analyses indicated a decrease in ER-alpha, but not in ER-beta, PR and AR mRNA levels following genistein treatment. In prepubertal rats exposed perinatally to 250 mg genistein per kg AIN-76A diet or 250 microg estradiol per kg diet, uterine ER-alpha, AR, and PR proteins were not altered significantly. We conclude that pharmacologic, but not physiologic concentrations of genistein can modulate sex steroid receptor expression in the rat uterus.

Epithelioid variant of malignant peripheral nerve sheath tumor (malignant schwannoma) of the urinary bladder.

Sarcoma represents less than 2% of all neoplasms diagnosed or recognized in effusions. Epithelioid peripheral nerve sheath tumor is a rare tumor that is difficult to differentiate from other epithelioid tumors without the use of ancillary studies. A 39-year-old paraplegic man presented with hematuria and a bladder mass that extended to involve the pelvic peritoneum. Light microscopy using hematoxylin-eosin, Papanicolaou, and immunohistochemical stains as well as transmission electron microscopy showed features of epithelioid malignant peripheral nerve sheath tumor with rhabdoid features and an accompanying eosinophilic infiltrate. Cytologic smears confirmed the similarities between the primary tumor in the bladder and the cells in the pelvic fluid and excluded the possibility of reactive changes related to postsurgical radiation. Ancillary studies were critical in narrowing the differential diagnoses and reaching the final conclusion.

Mortality due to schistosomiasis mansoni: a field study in Sudan.

Although schistosomiasis affects 200 million persons, 20 million of whom have advanced disease, little is known about the mortality pattern in areas of endemic schistosomiasis mansoni. In an attempt to assess the mortality rates in an endemic area in Sudan, we conducted two demographic surveys in a village in the Gezira area. Clinical, sonographic, and parasitologic examinations were performed in a randomly selected sample of 25% of the population in 1987 and 1994. One of us asked each head of household about the names, sex, and age of family members. Particularly, we asked about death in the family if any, history of schistosomiasis, abdominal swelling, and hematemesis. Possible causes of death were ascertained by reviewing medical records in the village dispensary and the district hospital. There were 42 deaths in the village. Four males died of hematemesis secondary to portal fibrosis. The crude mortality rate of schistosomiasis was is 51/100,000/year. The overall schistosomiasis fatality rate per year was 1/1,000 infected persons, but was as high as 11/100/infected patients with bleeding varices. These findings showed the impact of schistosomiasis on public health in this economically important region of Sudan.

Usefulness of molecular detection of human herpesvirus-8 in the diagnosis of Kaposi sarcoma by fine-needle aspiration.

Kaposi sarcoma (KS), a multifocal angioproliferative disorder, occurs most commonly in patients with AIDS, in whom it remains an important cause of morbidity and mortality. KS is often in the differential diagnosis in HIV-infected patients undergoing fine-needle aspiration (FNA). FNA diagnosis of KS is usually made by morphologic observation of scant tissue fragments composed of bland spindle cells and crush artifact. Human herpesvirus-8 (HHV-8) has been identified by polymerase chain reaction (PCR) amplification of DNA samples isolated from various epidemiologic forms of KS. In an attempt to improve the accuracy of KS diagnosis by FNA, we analyzed for the presence of HHV-8 DNA in 13 spindle-cell lesions evaluated by FNA: KS, 8 cases; granulomatous inflammation due to Mycobacterium avium-intracellulare, 1; nodular fasciitis, 1; dermatofibrosarcoma protuberans, 1; dermatofibroma, 1; benign spindle-cell lesion of nerve sheath origin, 1; and 2 lesions with lymphoid hyperplasia. DNA isolated from archival Wright-Giemsa-stained glass slides was used for the PCR amplification of the HHV-8 DNA sequences. All of the cases diagnosed as KS and 1 of the lymphoid hyperplasia cases were PCR-positive for HHV-8 DNA, while all other cases of spindle-cell lesions were negative. The molecular demonstration of HHV-8 DNA may be a useful adjunct in the diagnosis of KS by FNA.

Intraoperative cytologic diagnosis of granulomas: a retrospective study of 156 cases.

To avoid contamination of equipment and reduce risks of infection, intraoperative cytology (IOC) is a useful substitute to conventional frozen section in the diagnosis of infectious diseases. One of the various histomorphologic patterns of infections is the granuloma, which sometimes may be difficult to diagnose cytologically. In an attempt to assess accuracy and pitfalls of IOC in the diagnosis of granuloma, cases diagnosed as granuloma on IOC or on permanent sections (PS) at George Washington University Medical Center were collected for the period of September 1990 to March 1996. Cyto-histologic correlation was performed. During that time, a diagnosis of granuloma in either the IOC or PS was rendered in 156 of 5,901 IOC cases. IOC showed definite granuloma (87), suspicious for granuloma (23), and neither definite nor suspicious for granuloma in 46 cases. The latter group corresponded to neoplasms (5) and benign conditions (41). Eighty-five cases were accurately diagnosed as definite granuloma by both IOC and PS. Fifty-seven cases diagnosed as granuloma by PS corresponded on IOC to suspicious for granuloma (11), benign smear (41), and neoplasms (5). Only two cases were incorrectly diagnosed as granuloma on IOC: a neoplasm and a case of fibrosis. Overall, four cases of neoplasms were interpreted as suspicious for granuloma (3) or definite granuloma (1) on IOC, and five cases of granulomas were misdiagnosed as neoplasms on IOC. Four of these nine case were deferred for a PS diagnosis. IOC is a useful tool in the diagnosis of granulomas with a sensitivity of 60% and specificity of 99% and positive and negative predictive values of 98% and 99%, respectively. Rarely, neoplasms may be misdiagnosed as granulomas and vice versa.

The effectiveness of annual versus biennial mass chemotherapy in reducing morbidity due to schistosomiasis: a prospective study in Gezira-Managil, Sudan.

The most serious complication of schistosomiasis is periportal fibrosis, which affects a large number of subjects in endemic areas. Population-based chemotherapy remains the most effective way of controlling this disease. In an attempt to find the best way to deliver chemotherapy to the endemic population, we compared the impact of repeated annual versus biennial mass chemotherapy on morbidity due to schistosomiasis in two villages in Gezira, Sudan. One village was given five rounds of mass chemotherapy annually in the years 1990-1994 while the other village was given three rounds of mass chemotherapy biennially from 1988 to 1994. Before treatment, these villages had similar intensity of infection and prevalence. One round of either annual or biennial treatment reduced the intensity of infection, but not prevalence or morbidity. After two rounds of annual chemotherapy, infection rates, bloody diarrhea, and fibrosis in those 20 years of age and less were significantly reduced. Two rounds of biennial chemotherapy had a similar effect on rates and bloody diarrhea; however, fibrosis was reduced only after the third round of biennial chemotherapy. Prevalence of hepatosplenomegaly increased after both treatment regimens. Reinfection was most prominent in those 5-14 years of age. These findings support the general notion that repeated chemotherapy may be needed in areas of high transmission of schistosomiasis. We recommend two rounds of annual mass chemotherapy to significantly reduce infection and morbidity.

Suppressive effect of interleukin-4 neutralization differs for granulomas around Schistosoma mansoni eggs injected into mice compared with those around eggs laid in infected mice.

The principal pathological manifestation of murine Schistosoma mansoni infection is the egg-induced granuloma. Synchronous pulmonary granulomas forming around intravenously injected schistosome eggs are widely used to study the immunopathology of schistosomiasis. A number of anticytokine antibody treatments have a remarkable effect in modulating granulomas in this model but little effect on the size of hepatic granulomas around laid eggs during experimental infection. To examine this discrepancy, we examined the effects of anticytokine antibodies on liver and lung granulomas around injected eggs and around eggs laid during infection in both locations. Anti-interleukin-4 (IL-4) treatment greatly reduced the volume of granulomas around eggs injected into the liver via the portal vein and around eggs injected into the lung via the tail vein. On the contrary, granulomas around eggs laid by worms in either the liver or the lung during the course of infection were not significantly decreased in size by anti-IL-4 treatment. Thus, site is not important for the disparate effects of anti-IL-4 in granuloma formation around injected versus laid eggs. This effect is seen in naive and sensitized animals and is most probably due to differences in the quality of injected eggs versus those laid in situ by the worms.

Elevated expression of Th1 cytokines and nitric oxide synthase in the lungs of vaccinated mice after challenge infection with Schistosoma mansoni.

C57BL/6 mice were vaccinated with irradiated cercariae of Schistosoma mansoni, and, at various times after challenge infection, total lung mRNA was isolated to assess the induction of several cytokines that previously had been shown in in vitro studies to be involved in the activation of macrophages and/or endothelial cells for nitric oxide (NO) production and killing of schistosomula. Vaccinated mice demonstrated a highly significant increase in IFN-gamma mRNA upon subsequent infection when compared with infected nonvaccinated controls. A similar, although less dramatic, increase in two other macrophage-activating cytokines, TNF-alpha and IL-2, also was observed. In contrast, although the Th2 cytokines IL-4, IL-5, IL-10, and IL-13 were elevated in challenged vaccinated animals, only IL-10 and IL-13 showed increases that were significant with respect to the mRNA levels observed in challenged controls. Neutralization of IFN-gamma reduced immunity in vaccinated animals and resulted in decreased IFN-gamma, IL-2, IL-10, TNF-alpha, and IL-12 p40 but markedly increased IL-4, IL-5, and IL-13 mRNA expression and serum IgE levels. Pulmonary NO synthase expression was elevated in immunized mice at a time at which immune elimination of schistosomula is believed to occur. Moreover, suppression of NO synthase activity with the inhibitor aminoguanidine reduced immunity, as measured by a 32 to 33% increase in worm burden. Together, these data support previous in vitro studies that suggest a role for NO in schistosomulum killing. Furthermore, the observation that the down-regulatory cytokines IL-4, IL-10, and IL-13 are induced together with IFN-gamma may provide an explanation for the failure of this vaccine to provide complete protection.

Increased susceptibility of mice infected with Schistosoma mansoni to recombinant vaccinia virus: association of viral persistence with egg granuloma formation.

BALB/c mice infected 7 weeks previously with Schistosoma mansoni and challenged with a recombinant vaccinia virus vPE16 expressing the human immunodeficiency virus envelope protein gp160 show a marked delay in hepatic viral clearance as compared to mice infected with vPE16 alone. This increase in viral persistence is accompanied by reduced gp120-specific Th1-associated cytokine responses as well as by impaired cytotoxic T lymphocyte (CTL) activity against targets expressing epitopes of the same antigen. To investigate the contribution of these defects to the observed delay in clearance of recombinant vaccinia virus, animals were challenged with vPE16 at different times following S. mansoni infection, and virus titers in tissues and viral-specific immune responses were measured simultaneously in the same animals. While normal resolution of virus occurred in schistosome-infected mice prior to parasite egg deposition, persistence within the liver was observed in animals challenged during the onset and peak phase of granuloma formation (6 to 8 weeks after S. mansoni infection). At later times, when schistosomiasis is in its chronic phase, normal viral clearance returned. This time course of viral resolution correlated in part with the observed pattern of decreased Th1 cytokine production toward viral antigens but was clearly less temporally related to the defect in virus-specific CTL activity. Immunohistochemical staining of liver sections from vaccinia/S. mansoni co-infected mice with polyclonal anti-vaccinia antibodies revealed that viral epitopes are localized primarily within granulomas. These experiments suggest that egg granulomas, by providing a microenvironment for viral expression, in combination with the cytokine imbalance present during schistosome infection, can promote the expansion of vaccinia virus and possibly other viral agents.

Predictors of upper gastrointestinal bleeding in patients with schistosomal periportal fibrosis.

A case-control study was conducted between 1985 and 1987 in the Gezira-Managil area of central Sudan to assess the major predictors of haematemesis. Eighty-four patients who had suffered at least one attack of oesophageal bleeding and had schistosomal periportal fibrosis demonstrated by ultrasonography were compared with 173 subjects without bleeding but with ultrasonographic evidence of periportal fibrosis. A splenic longitudinal dimension of more than 11 cm, periportal fibrosis worse than grade I and varices more than grade I were independently associated with a significant risk of variceal bleeding. Age, sex, presence of a palpable liver and portal vein diameter were not associated with a significant risk of bleeding after adjustment for potential confounding variables. Factors identified in this study could be helpful in the prophylactic management of patients with complicated schistosomiasis.

Demonstration of urinary eosinophils in Schistosoma haematobium: a comparative study among three different stains.

Three stains, Hansel's stain, alkaline erythrocin B (AEB) and naphthalene black (NB), were used to demonstrate eosinophils in the urine of patients infected with Schistosoma haematobium. Hansel's stain was superior to the other two stains; it stained eosinophils bright red and their nuclei faint blue, and they were easily differentiated from neutrophils, lymphocytes, macrophages and epithelial cells. The method using AEB took longer than Hansel's stain and 10% of the specimens were lost during staining with this method. Like eosinophils, the neutrophils took up NB stain and their nuclei stained poorly with the counterstain.

Biology and pathology of Schistosoma mansoni and Schistosoma japonicum infections in several strains of nude mice.

Schistosoma mansoni and S. japonicum infections in nude mice (nu/nu) were compared with infections in nu/+ heterozygotes or intact mice. Seven to 12 weeks after exposure to S. mansoni, the responses of Swiss NCR, C3H, BALB/c and C57B1/6 nude mice did not differ substantially. Nude mice of all these strains showed minute granulomas around eggs in the liver and minimal hepatic fibrosis. Microvesicular and necrotizing changes in hepatocytes were similar in all mouse strains, and S. mansoni infections were frequently lethal to nude, but not to intact mice between the seventh and ninth weeks of infection. Nude mice that survived the ninth week of infection generally lived until the 12th week. The number of eggs per mature worm pair in the tissues of S. mansoni-infected nude mice was similar to the number in intact mice, but nude mice passed fewer eggs in the feces. Nude mice that received serum from infected intact mice excreted eggs in the stool in numbers equivalent to intact mice, but continued to form minute granulomas around S. mansoni eggs. Reconstitution with fetal thymus or with splenocytes from normal or S. mansoni-infected mice partially or completely restored hepatic granuloma size, granuloma eosinophils, hepatic fibrosis, and excretion of eggs in the feces. In contrast to S. mansoni infection, S. japonicum infections in nude mice did not cause necrosis of hepatocytes or excessive mortality, and S. japonicum eggs were passed in the feces in numbers equivalent to those passed by infected intact mice.

Infection with Schistosoma mansoni in two different endemic areas: a comparative population-based study in Elziedab and Gezira-Managil irrigation schemes, Sudan.

A cross-sectional survey of schistosomiasis was carried out in five villages around the Elziedab irrigation scheme, in the north, and three villages in the Gezira-Managil area in central Sudan. Stools and urine from 53% (2832 individuals) and 72% (3684 individuals) of the population of these villages, respectively, were examined using the modified Kato thick smear for stools and sedimentation for urine. Clinical history and examination were done on 2832 subjects (53%) in Elziedab and on 893 (18%) randomly selected samples in Gezira-Managil. Prevalence of Schistosoma mansoni was 36% in Elziedab and the mean egg count was 150 eggs per gram of faeces (e.p.g.). Prevalence of bloody diarrhoea was 6%, hepatomegaly 6% and splenomegaly 10%. There was a significant association between these parameters and infection in the age group 10-24 years. Prevalence and intensity in Gezira-Managil area were significantly higher than in Elziedab, 52% and 234 e.p.g. Prevalences of bloody stool 29%, hepatomegaly 17% and splenomegaly 15% were also significantly higher than in Elziedab. These parameters were unrelated to the presence of eggs in the stool. Advanced hepatosplenic schistosomiasis is less than 1% in both areas. While S. haematobium was not found in Elziedab, its prevalence varied from 10 to 15% in Gezira-Managil area. In conclusion, S. mansoni is much less prevalent in Elziedab than Gezira, signs and symptoms are much less prominent in Elziedab, and most of the symptoms are unrelated to the presence of eggs in the stool.

Liver sonography in an area endemic for schistosomiasis haematobium.

Through the use of portable ultrasonography, eight cases (2%) of periportal fibrosis were identified in a random sample of 400 subjects selected from a village with a high prevalence and morbidity due to schistosomiasis haematobium in the White Nile Province of Sudan. In contrast, 36 cases (15%) of fibrosis were seen in an area with a similar prevalence and morbidity due to schistosomiasis mansoni in the Gezira Managil region of Sudan. Although there was only one case of Schistosoma mansoni as determined by repeated stool examination of the entire sample population in the first village, the majority of those with fibrosis and age-matched controls showed serologic evidence of active S. mansoni infection. This led to the conclusion that the cases of periportal fibrosis seen in the White Nile Province are most probably due to S. mansoni rather than to S. haematobium.

Post-kala-azar dermal leishmaniasis in the Sudan: peripheral neural involvement.

Four patients developed post-kala-azar dermal leishmaniasis and neuritis (PKDL) 1 to 6 months following apparently successful treatment of kala-azar. The duration of the lesion varied between 1 month and nearly 5 years. The lesions were macules, papules, or nodules affecting the face, extremities, and trunk. The diagnosis was made by demonstration of the parasite in slit smear and biopsies and by a positive direct agglutination test (DAT). Histologically, the patients were found to have neuritis affecting the cutaneous nerves in the lesion only. The nerves showed a lymphohistiocytic infiltration and occasionally parasites. There was no impairment of sensation. Response to sodium stibogluconate was good. PKDL may simulate leprosy both clinically and pathologically.

Evaluation of eosinophiluria in the diagnosis of schistosomiasis hematobium: a field-based study.

Using Hansel's stain, eosinophiluria greater than 5% of total urinary white blood cells was found in 59% of a randomly selected population sample in an area endemic for schistosomiasis hematobium. The prevalence and mean level of eosinophiluria were significantly higher in infected subjects than in noninfected subjects (P less than 0.05). The sensitivity (80%), specificity (86%), and positive predictive value (82%) of eosinophiluria as a diagnostic index for schistosomiasis hematobium were significantly higher (Youdin index 0.66; P less than 0.05) than those of proteinuria, hematuria, and leukocyturia taken singly or in combination. However, unlike the latter three measurements, this method involves microscopy. There is a great need for a chemical method for measuring eosinophiluria.

Evaluation of haematuria as an indirect screening test for schistosomiasis haematobium: a population-based study in the White Nile province, Sudan.

Haematuria elicited in the history, seen macroscopically or detected by reagent strips, was used as an indirect screening test for Schistosoma haematobium infection in Um-Hani Irrigation Scheme in the White Nile province, Sudan. These approaches were used separately or combined in different sequences. Reagent strips alone detected 81% of cases and 88% of those who excreted 50 egg/10 ml of urine or more. The sequence of observation of gross haematuria followed by screening with reagent strips and then taking history of haematuria had the highest sensitivity of all the orders, 0.87, and it saved 18% of reagent strips. If history and inspection were done first, followed by reagent strips, the sensitivity would be 0.86 and 47% of strips would be saved. The specificity of haematuria as a diagnostic index for schistosomiasis, however, was low.