Characterization of hepatitis E-specific cell-mediated immune response using IFN-gamma ELISPOT assay

In developing countries, hepatitis E (HEV) and hepatitis A (HAV) are the major causes of acute viral hepatitis with similar feco-oral modes of transmission. In contrast to the high seroprevalence of hepatitis A infection, a low seroprevalence of HEV among children in endemic areas has been reported. These data suggest the possibility that silent HEV infection is undiagnosed by the current available methods. Many of the serological tests used for HEV diagnosis have poor specificity and are unable to differentiate among different genotypes of HEV. Moreover, the RT-PCR used for HEV isolation is only valid for a brief period during the acute stage of infection. Cell-mediated immune (CMI) responses are highly sensitive, and long lasting after sub-clinical infections as shown in HCV and HIV. Our objective was to develop a quantitative assay for cell-mediated immune (CMI) responses in HEV infection as a surrogate marker for HEV exposure in silent infection. Quantitative assessment of the CMI responses in HEV will also help us to evaluate the role of CMI in HEV morbidity. In this study, an HEV-specific interferon-gamma (IFN-gamma) ELISPOT assay was optimized to analyze HEV-specific CMI responses. We used peripheral blood mononuclear cells (PBMC) and sera from experimentally infected chimpanzees and from seroconverted and control human subjects to validate the assay. The HEV-specific IFN-gamma ELISPOT responses correlated strongly and significantly with anti-HEV ELISA positive/negative results (rho=0.73, p=0.02). Moreover, fine specificities of HEV-specific T cell responses could be identified using overlapping HEV ORF2 peptides.

Schistosoma infection inhibits cellular immune responses to core HCV peptides

Patients coinfected with hepatitis C virus (HCV) and the trematode, Schistosoma mansoni, have an increased incidence of viral persistence and accelerated fibrosis. To investigate immunological mechanisms responsible for this more aggressive natural history of HCV, the core HCV-specific T-cell responses were analysed in 44 donated blood units rejected because they had antibodies to HCV (anti-HCV). Half also had anti-S. mansoni antibodies, evidence of past or active infection. HCV-specific ELISPOT responses were examined using pools of 180 overlapping 9-mer peptides with offsets of one covering the core of HCV genotype 4a. Comparison of T-cell responses in blood units positive for both anti-HCV and anti-Schistosoma antibodies with blood units positive only for anti-HCV antibodies showed a significant decrease in core-specific T-cell IFN-gamma (505+/- 46 vs. 803 +/- 66 ISC/10(6) cells, P < 0.001), IL-4 (2 +/- 108 vs. 641 +/- 131 ISC/10(6) cells, P < 0.001), and IL-10 (159 +/- 105 vs. 466 +/- 407 ISC/10(6) cells, P < 0.002) responses. In contrast, there was no significant difference in cell-mediated immune response (CMI) to PHA mitogen between these two groups. Therefore, we concluded T cells from persons with anti-Schistosoma have reduced IFN-gamma, IL-4, and IL-10 secreting HCV-specific T-cell responses. This may explain why Schistosoma coinfection increases persistence and severity of HCV infection.

Randomised double-blinded trial evaluating silymarin for chronic hepatitis C in an Egyptian village: study description and 12-month results

BACKGROUND/AIMS

A double-blinded trial evaluating silymarin, an herbal supplement for liver disease, to prevent complications of chronic hepatitis C virus infection has not been done.

SUBJECTS

One hundred and seventy-seven consenting residents of an Egyptian village with chronic hepatitis C virus were randomly assigned to receive either silymarin or multivitamin supplements.

METHODS

Participants had baseline and follow-up clinical, ultrasound, blood tests and quality-of-life assessments. Community nurses visited weekly to ascertain compliance, distribute supplements and record adverse effects.

RESULTS

At 12 months almost all of 141 remaining subjects reported feeling better, although symptoms and quality-of-life scores did not differ between the silymarin and multivitamin groups. Both the silymarin and vitamins were tolerated equally well; and >95% of supplements were taken by >95% of subjects. One in each group had no detectable hepatitis C virus antibodies while two in the silymarin group and three receiving multivitamins had undetectable hepatitis C virus RNA. Serum alanine aminotransferase elevations did not differ between groups. Serum hepatic fibrosis marker, hyaluronic acid and YKL-40, and abdominal ultrasound results were similar in both groups and may have progressed slightly at 12 months.

CONCLUSIONS

The recommended dose of silymarin can be safely taken for 1 year and improves symptoms and general well-being, but has no effect upon hepatitis C virus viremia, serum ALT, or serum and ultrasound markers for hepatic fibrosis. More prolonged evaluation and a higher dose may be required to ascertain whether milk thistle supplements prevent complications of chronic hepatitis C virus.

Hepatitis C virus infection in a community in the Nile Delta: risk factors for seropositivity

The purpose of this study was to identify risk factors for hepatitis C virus (HCV) infection in a rural village in the Nile Delta with a high prevalence of antibodies to HCV (anti-HCV). One half of the village households were systematically selected, tested for anti-HCV, and interviewed: 973 of 3,999 (24.3%) subjects were anti-HCV-positive (reflecting prior HCV infection but not necessarily current liver disease), with nearly equal prevalence among males and females. Anti-HCV prevalence increased sharply with age among both males and females, from 9.3% in those 20 years of age and younger to >50% in those older than 35, suggesting a cohort effect with reduced transmission in recent years. Multivariate regression was used to estimate independent effects of risk factors on seropositivity. Among those over 20 years of age, the following risk factors were significantly associated with seropositivity: age (P <.001); male gender (odds ratio [OR] = 2.5, 95% CI = 1.3-4.7); marriage (OR = 4.1, 2.4-6.9); anti-schistosomiasis injection treatment (OR = 2.0, 1.3-2.9); blood transfusion (OR = 1.8, 1.1-2.9), invasive medical procedure (surgery, catheterization, endoscopy, and/or dialysis) (OR = 1.5, 1.1-1.9); receipt of injections from "informal" health care provider (OR = 1.3, 1.0-1.6); and cesarean section or abortion (OR = 1.4, 1.0-1.9). Exposures not significantly related to anti-HCV positivity in adults included: history of, or active infection with, Schistosoma mansoni, sutures or abscess drainage, goza smoking in a group, and shaving by community barbers. Among those 20 years old or younger, no risk factors were clearly associated with anti-HCV positivity; however, circumcision for boys by informal health care providers was marginally associated with anti-HCV (OR = 1.7, 1.0-3.0). Prevention programs focused primarily on culturally influenced risks in rural Egyptian communities are being implemented and evaluated.

Hepatitis C in a community in Upper Egypt: I. Cross-sectional survey

The prevalence of antibody to hepatitis C virus (anti-HCV) was determined in a cross-sectional survey in a village in Upper Egypt. Exposure and demographic characteristics were obtained through a questionnaire. Antibody to hepatitis C virus was assessed using a second generation enzyme immunoassay, and the presence of HCV RNA was tested using a reverse transcriptase-polymerase chain reaction. Collection of blood samples was targeted at those > or = 5 years old, and obtained from 62.8%. This report describes the community, the HCV infection characteristics of the subjects, and evaluates some factors associated with presence of anti-HCV. Of the 6,031 participants, 522 (8.7%) were anti-HCV positive. Prevalence was higher among males than females (11.3% versus 6.5%; P < 0.001). It was greater among those > 30 years of age than among those < or = 30 years of age (20.0% versus 3.6%; P < 0.001). Those who were less educated, farmed, provided health care, and were currently married had a significantly higher anti-HCV prevalence than those who were not; however, these associations were not significant after adjusting for age. Although active infections with Schistosoma haematobium were not associated with anti-HCV, a history of past infection was (age-adjusted risk ratio [RR] = 2.1, 95% confidence interval [CI] = 1.8, 2.4); 134 persons who had a history of receiving parenteral anti-schistosomal therapy had a higher age-adjusted RR (3.0; 95% CI = 2.5, 3.7) for anti-HCV than those who did not. Hepatitis C virus RNA was detected in 62.8% of the anti-HCV positive subjects, without significant variation by age, gender, education, or marital status. The prevalence of anti-HCV in Upper Egypt is high, albeit lower than in Lower Egypt, with continuing but limited transmission indicated by the lower prevalence in residents < or = 30 years old.

Racial differences in reported Lyme disease incidence

In the United States, the incidence of Lyme disease is considered to be disproportionately high among Whites because of risk of exposure. For assessment of racial differences in Lyme disease incidence and the role of risk exposure, incidence rate ratios (IRRs) for Lyme disease and its manifestations between Whites and African Americans in Maryland and in its focus of endemicity, the Upper Eastern Shore, were calculated. Calculations were based on reported cases of Lyme disease in Maryland during the years 1992-1996. The IRR for Lyme disease between Whites and African Americans was 6.3 (95% confidence interval (CI): 5.0, 8.0), decreasing to 1.8 (95% CI: 1.2, 2.7) for the Upper Eastern Shore. Statewide, there was a significant difference between the White to African American IRR for erythema migrans and for Lyme disease-associated arthritis, at 17.7 (95% CI: 11.2, 27.8) and 2.3 (95% CI: 1.7, 3.2), respectively. On the Upper Eastern Shore, the IRR for arthritis reversed, indicating higher incidence among African Americans than among Whites: IRR = 5.7 (95% CI: 2.4, 13.9) for erythema migrans and IRR = 0.7 (95% CI: 0.4, 1.1) for arthritis. White patients were more likely to have erythema migrans (risk ratio = 2.8, 95% CI: 1.9, 4.1) and less likely to have arthritis than were African Americans (risk ratio = 0.4, 95% CI: 0.3, 0.5). Among all patients, there was a significant negative association between arthritis and erythema migrans. Although much of the racial disparity in incidence rates diminishes in a rural, endemic area, consistent with exposure risk being responsible for much of the variation, a difference remains. This may be due to failure to recognize early disease (erythema migrans) among African Americans, resulting in increased rates of late manifestations. Geographic spread of the disease warrants efforts to increase awareness of Lyme disease and its manifestations among people of color and the health care providers who serve them.

Hepatitis C virus (HCV) infection in a community in the Nile Delta: population description and HCV prevalence

This report describes a cross-sectional survey of the prevalence of antibodies to hepatitis C virus (anti-HCV) in a rural Egyptian community in the Nile Delta. One half of the village households were systematically selected and examined by questionnaire and testing sera for anti-HCV and HCV RNA. Blood samples were obtained from 3, 888 (75.4%) of 5,156 residents >/=5 years of age; an additional 111 samples were obtained from children younger than 5 years. Overall, 973 (24.3%) of 3,999 residents were anti-HCV-positive, and the age- and gender-adjusted seroprevalence was 23.7%. Anti-HCV prevalence increased sharply with age, from 9.3% in those 20 years of age and younger to >50% in those older than 35 years. Currently or previously married individuals were more likely to be seropositive than those never married, controlling for age (Mantel-Haenszel risk ratio = 1.8; 95% CI: 1.3, 2.6). Of the 905 anti-HCV-positive samples tested, 65% were also positive for HCV RNA. Active schistosomal infection was not associated with anti-HCV status; however, history of antischistosomal injection therapy (reported by 19% of anti-HCV positives) was a risk for anti-HCV (age-adjusted risk ratio = 1.3; 95% CI: 1.2, 1.5). This study, the largest community-based survey to date, supports earlier reports of high levels of anti-HCV among adults in rural areas of Egypt, although many of those who are seropositive will not have active liver disease. The large reservoir of HCV infection in the community provides an opportunity to investigate risk factors for transmission, the natural history of infection and effectiveness of preventive methodologies, and raises concern about the prospect of an increasing incidence of chronic liver disease in the coming decades.

Prevalence of antibodies to hepatitis E in two rural Egyptian communities

A population-based serosurvey in two rural Egyptian communities was used to assess age-specific prevalence of antibody to hepatitis E virus (anti-HEV). One community is in the Nile Delta (11,182 inhabitants; 3,997 participants) and the other in Upper Egypt (10,970 inhabitants; 6,029 participants). Samples were tested for anti-HEV with a commercial enzyme-linked immunoassay (ELISA) based on antigens derived from open reading frame (ORF)2 and ORF3. Although there was a clear difference in sensitivity among the lots of the commercial test used, it was still possible to determine the seroprevalence. The seroprevalence of anti-HEV exceeded 60% in the first decade of life, peaked at 76% in the second decade and remained above 60% until the eighth decade. Prevalence of this magnitude is among the highest reported in the world, with an age-specific pattern more similar to hyperendemic hepatitis A virus transmission than generally described. Lot-to-lot variation in the sensitivity of the commercial ELISA kit highlights a problem when comparing seroepidemiologic studies of different populations.

The role of parenteral antischistosomal therapy in the spread of hepatitis C virus in Egypt

BACKGROUND

The population of Egypt has a heavy burden of liver disease, mostly due to chronic infection with hepatitis C virus (HCV). Overall prevalence of antibody to HCV in the general population is around 15-20%. The risk factor for HCV transmission that specifically sets Egypt apart from other countries is a personal history of parenteral antischistosomal therapy (PAT). A review of the Egyptian PAT mass-treatment campaigns, discontinued only in the 1980s, show a very high potential for transmission of blood-borne pathogens. We examine the relative importance of PAT in the spread of HCV in Egypt.

METHODS

The degree of exposure to PAT by cohort was estimated from 1961-86 Ministry of Health data. A cohort-specific exposure index for PAT was calculated and compared with cohort-specific HCV prevalence rates in four regions.

FINDINGS

HCV prevalence was calculated for 8499 Egyptians aged 10-50 years. A significant association between seroprevalence of antibodies to HCV and the exposure index (1.31 [95% CI 1.08-1.59]; p=0.007) was identified across four different regions. In all regions cohort-specific HCV prevalence was lowest in children and young adults than in older cohorts. These lower prevalence rates coincided with the gradual and final replacement of PAT with oral antischistosomal drugs at different points in time in the four regions.

INTERPRETATION

The data suggest that PAT had a major role in the spread of HCV throughout Egypt. This intensive transmission established a large reservoir of chronic HCV infection, responsible for the high prevalence of HCV infection and current high rates of transmission. Egypt's mass campaigns of PAT may represent the world's largest iatrogenic transmission of blood-borne pathogens.

The epidemiology of schistosomiasis in Egypt: Gharbia Governorate

Health questionnaires and parasitologic examinations of urine and stool were performed upon a stratified random sample of 14,344 individuals from 1,952 households in 34 rural communities in Gharbia Governorate of Egypt to investigate the prevalence of, risk factors for, and changing pattern of infection with Schistosoma sp. A subset, every fifth household, of 1,973 subjects had physical and ultrasound examinations to investigate prevalence of and risk factors for morbidity. Community prevalence of Schistosoma mansoni ranged from 17.9% to 79.5% and averaged 37.7%. The geometric mean egg count (GMEC) was 78.9 eggs/gram of feces. The prevalence and intensity of infection was 40-50% and 70-100 eggs/gram of feces in those > or =10 years of age. Schistosoma haematobium was detected in 5 of the 34 communities. The maximum infection rate was 2.8% and mean GMEC in the five communities was 2.1/10 ml of urine. The overall prevalence of S. haematobium in the governorate was 0.3%. Risk factors for infection with S. mansoni were male gender, an age >10 years, living in smaller communities, exposures to canal water, prior therapy for schistosomiasis, or blood in the stool (in children only). Morbidity detected by physical examination or ultrasonography did not correlate with S. mansoni infection in individuals with the exception of periportal fibrosis (PPF, odds ratio [OR] = 1.25). Periportal fibrosis was detected in more than half of the subjects by ultrasonography; 5.3% had grade II lesions and 1.0% had the most severe grade III changes. Risk factors for morbidity as manifested by ultrasonographically detected PPF were similar to those for infection. Periportal fibrosis had a negative relationship with abdominal pain (OR = 0.45) and hepatomegaly detected by physical examination and ultrasonography (ORs = 0.72 and 0.68), but it was associated with splenomegaly (ORs = 4.14 and 3.55). The prevalence of PPF, hepatomegaly, and splenomegaly increased with age. There was no relationship between community burden of schistosomiasis mansoni and any measurements of morbidity with the exception of splenomegaly detected by physical examination (r = 0.40). Schistosoma mansoni has almost completely replaced S. haematobium in Gharbia, which has a high prevalence and moderate intensity of S. mansoni infection. Periportal fibrosis was detected by ultrasonography in more than half of the subjects, and 1 in 16 had grade II and III lesions. The only relationship between PPF and other morbidity findings was its positive relationship with splenomegaly and negative association with hepatomegaly. Hepatic morbidity is common in communities in Gharbia but the role of schistosomiasis mansoni in this is uncertain.

The epidemiology of schistosomiasis in Egypt: Menofia Governorate

Health questionnaires and parasitologic examinations of urine and stool were performed upon a stratified random sample of 10,899 individuals from 1,537 households in 27 rural communities in Menofia Governorate in Egypt in 1992 to investigate the prevalence of, risk factors for, and changing pattern of infection with Schistosoma sp. in the governorate. A subset, every fifth household, or 1,480 subjects, had physical and ultrasound examinations to investigate prevalence of and risk factors for morbidity. The prevalence of S. mansoni ranged from 0.3% to 72.9% and averaged 28.5%. The geometric mean egg count was 81.3 eggs/gram of stool. Age-stratified prevalence and intensity of infection was 30-40% and 60-80 eggs/gram of stool from the age of 10 onward; males had higher infection rates and ova counts than females in all age groups > 10 years old. Schistosoma haematobium was rare, being consequential in only 1 community. Risk factors for S. mansoni infection were male gender; age > 10 years; living in smaller communities; exposures to canal water; history of or treatment for schistosomiasis or blood in the stool; detection of splenomegaly by either physical or ultrasound; and ultrasound-detected periportal fibrosis (PPF). The more severe grades of PPF were rarely (21 of 1,450 examinations) detected. Risk factors for morbidity, i.e., ultrasound-detected PPF, were similar to those for infection. Schistosoma mansoni has almost totally replaced S. haematobium in Menofia. The prevalence of S. mansoni in rural communities remains high and average intensities of infection are moderate. The association of morbidity with schistosomal infection was variable and is obviously markedly influenced by both the frequent use of antischistosomal chemotherapy in communities in Menofia and by the prevalence of complications from chronic viral hepatitis in the population: hepatomegaly did not correlate with infection; PPF and splenomegaly, however, were related to S. mansoni infection in both individuals and communities.

The epidemiology of schistosomiasis in Egypt: summary findings in nine governorates

Health questionnaires and parasitologic examinations of urine and stool were evaluated from a stratified random sample of 89,180 individuals from 17,172 households in 251 rural communities in 9 governorates of Egypt to investigate the prevalence of, risk factors for, and changing pattern of infection with Schistosoma sp. in Egypt. A subset, every fifth household, or 18,600 subjects, had physical and ultrasound examinations to investigate the prevalence of and risk factors for morbidity. Prevalence of S. haematobium in 4 governorates in Upper Egypt in which it is endemic ranged from 4.8% to 13.7% and averaged 7.8%. The geometric mean egg count (GMEC) ranged from 7.0 to 10.0 ova/10 ml of urine and averaged 8.1. Age stratified prevalence of infection peaked at 15.7% in the 10-14-year-old age group and decreased to 3.5-5.5% in all groups more than 25 years of age. Age-stratified intensity of infection peaked at approximately 10.0 ova/10 ml of urine in the 5-14-year-old age groups and was about half that in all groups more than 25 years of age. Males had higher infection rates and ova counts than females in all age groups. Schistosoma mansoni was rare in Upper Egypt, being consequential in only Fayoum, which had a prevalence of 4.3% and an average intensity of infection of 44.0 ova/g of stool. Risk factors for S. haematobium infection were male gender, an age <21 years old, living in smaller communities, exposures to canal water; a history of, or treatment for, schistosomiasis, a history of burning micturition or blood in the urine, and reagent strip-detected hematuria or proteinuria. The more severe grades (II and III) of ultrasonography-detected periportal fibrosis (PPF) were rare (15 of 906) in these schistosomiasis haematobia-endemic governorates. Risk factors for morbidity (ultrasonography-detected urinary bladder wall lesions and/or obstructive uropathy) were similar to those for infection, with the exception that risk progressively increased with age. Subjects with active S. haematobium infections were 3 times as likely as those without active S. haematobium infections to have urinary tract morbidity. The prevalence of S. mansoni in 5 governorates in Lower Egypt, where it is endemic, ranged from 17.5% to 42.9% and averaged 36.4%. The GMEC ranged from 62.6 to 93.3 eggs/g of stool and averaged 81.3. Age-stratified prevalence of infection peaked at 48.3% in the 15-19-year-old age group, but averaged 35-45% in all groups more than 10 years of age. The intensity of infection was highest in the 10-14-year-old age group, and showed a range of 70-85 eggs/g of stool in those > or =5 years of age. Males had higher infection rates and ova counts than females in all age groups. Schistosoma haematobium was rare in these governorates; Ismailia (1.8%) had the highest infection rate. Risk factors for S. mansoni were male gender, an age >10 years old, living in smaller communities, exposures to canal water, a history of, or treatment for, schistosomiasis or blood in the stool, detection of splenomegaly by either physical examination or ultrasonography, and ultrasonography-detected PPF. The more severe grades (II and III) accounted for 463 (13.3%) of the 3,494 having ultrasonography-detected PPF. Risk factors for morbidity (ultrasonography-detected PPF) were similar to those for infection except that inhabitants of smaller communities were not at increased risk. Active S. mansoni infection increased the odds ratio (OR) of having PPF by 1.37. In comparison with others with normal-size livers, subjects having hepatic enlargement in either the midclavicular line or the midsternal line detected by physical examination or ultrasonography had a reduced risk (ORs = 0.64-0.72) of PPF. The prevalences of lesions detected by ultrasonography were 23.7% for enlargement of right lobe of the liver, 11.3% for enlargement of left hepatic lobe, 20.6% for splenomegaly, and 50.3% for PPF. Schistosoma mansoni has almost totally replaced S. haematobium in Lower E

The epidemiology of schistosomiasis in Egypt: methods, training, and quality control of clinical and ultrasound examinations

Morbidity due to schistosomiasis was evaluated in a subpopulation of 14,000 of the randomized sample in the Epidemiology 1, 2, 3 Project. It was measured by using a standardized questionnaire for obtaining medical history and symptoms and by performing standardized physical and ultrasound examinations. Reported herein are descriptions of the methods and training and quality control efforts made to insure that the morbidity data was reliable and consistent when collected by 7 different teams in 9 different governorates.

The epidemiology of schistosomiasis in Egypt: Minya Governorate

Risk factors, prevalence, and intensity of infection with Schistosoma sp. and prevalence and magnitude of morbidity caused by schistosomiasis was assessed in a stratified random sample of 16,433 subjects from 2,409 households in 33 rural communities in Minya Governorate, Egypt. The prevalence of S. haematobium ranged from 1.9% to 32.7% among the communities and averaged 8.9%. The average intensity of infection was a geometric mean egg count (GMEC) of 8.5 per 10 ml of urine and ranged from 1.6 to 30.9. Prevalence was maximum (18-20%) in those 10-20 years of age and higher in males than in females. Intensity of infection followed the same pattern. Infection with S. mansoni was present almost exclusively in a single village, confirming spread of this species up the Nile River and its focality in Minya. Risk factors for S. haematobium infection were an age from 11 to 20; male gender; males bathing in, women washing clothing or utensils in, and children swimming or playing in canals; and a history of, or treatment for, schistosomiasis. Recent history of burning micturition was associated with infection in children but not in adults, while a history of blood in urine correlated with S. haematobium infection in both age groups. Reagent strip-detected hematuria and proteinuria were highly associated, particularly in children, with S. haematobium infection. The presence of hepatomegaly or splenomegaly on physical examination was not associated with S. haematobium ova in the urine. Hepatomegaly, as measured by ultrasonography in the midclavicular line or the midsternal line, or ultrasonography-detected splenomegaly were not present more frequently in infected subjects than in uninfected subjects. Schistosoma ova were not detected more frequently in urine of subjects with ultrasonography-detected periportal fibrosis than in the urine from subjects without this finding. Ultrasonography-detected urinary bladder wall lesions were detected in only 6 (0.3%) subjects and obstructive uropathy was observed in 54 (2.7%) subjects. The absence of an association between prevalence of urinary tract morbidity and S. haematobium infections was surprising. Two possible explanations are 1) that repeated chemotherapy has reduced the prevalence of urinary tract morbidity and 2) that morbidity was not being detected by the ultrasonographic operators.

The epidemiology of schistosomiasis in Egypt: Assiut governorate

In the Assiut, Egypt Epidemiology 1, 2, 3 investigation, a sample of 14,204 persons in 10 villages, 31 ezbas (satellite communities), and 2,286 households was drawn from a rural population of 1,598,607. Parasitologic examination of urine and stool were made for Schistosoma haematobium and S. mansoni, and physical and ultrasound examinations were made on a 20% subsample. The overall estimated prevalence of S. haematobium was 5.2 +/- 0.5 (+/- SE). This varied considerably by village and ezba, ranging from 1.5% to 20.9%, with ezbas having a slightly higher overall prevalence than villages. The overall estimated geometric mean egg count was 6.6 +/- 0.5 eggs per 10 ml of urine and was consistently low throughout the communities. Infection with S. haematobium was associated with age (peak prevalence of 10.6 +/- 1.5% in 15-19-year-old age group) males, children playing in the canals, a history of blood in the urine, and reagent strip positivity for hematuria and proteinuria. The prevalence of either hepatomegaly or splenomegaly detected by physical examination was low (4.0% and 1.5%, respectively). The prevalence of hepatomegaly determined by ultrasonography was substantially higher, 24.1%. The prevalence of periportal fibrosis (PPF) was 12.0%, but grade II or III PPF was present in less than 1%. Ultrasonography-determined hepatomegaly, in both the midclavicular line and the midsternal line, increased by age to more than 30%. Periportal fibrosis was more common in the age groups in which infection rates were the highest. At the village and ezba level of analysis, the prevalence of hepatomegaly, splenomegaly, and PPF tended to be higher in communities having the highest prevalence of infection with S. haematobium.

The epidemiology of schistosomiasis in Egypt: Fayoum Governorate

Health questionnaires and parasitologic examinations of urine and stool were performed upon a stratified random sample of 7,710 individuals from 1,109 households in 21 rural communities in Fayoum Governorate, Egypt in 1992 to investigate the prevalence of, risk factors for, and changing pattern of, infection with Schistosoma sp. in the governorate. A subset, every fifth household, or 1,038 subjects, had physical and ultrasound examinations to investigate prevalence of, and risk factors for, morbidity. The prevalence of S. haematobium ranged from 0% to 27.1% and averaged 13.7%. The geometric mean egg count (GMEC) was 10.0 eggs/10 ml of urine. Age-stratified prevalence and intensity of infection were 18-25% and 10-15 eggs/10 ml of urine in those 5-25 years of age. Schistosoma mansoni were detected in inhabitants of 13 communities, but 78.5% of the infections were focally present in a group of 4 satellite hamlets around a single village. The overall prevalence of S. mansoni in the governorate was 4.3% and the GMEC was 44.0 ova/g of stool. Risk factors for infection with either species were male gender, an age <20 years, living in smaller communities, and exposures to canal water by males. Histories of burning micturation, blood in the urine, or prior schistosomiasis and reagent strip-detected hematuria and proteinuria were risks for S. haematobium, but not for S. mansoni. Both urinary tract and higher grades of hepatic morbidity were rare. Obstructive uropathy was present in 6.3% of the subjects and was more common in males and older people. Ultrasonography-detected bladder lesions were present in 5.2% and correlated with S. haematobium only in younger subjects and in those with hematuria and proteinuria. The prevalences of hepatomegaly, splenomegaly, and periportal fibrosis (PPF) were associated with each other and increased with age and in males. Ultrasonography-detected hepatomegaly and splenomegaly were weakly associated with S. mansoni infections only in children. The prevalence of PPF was greater in the 4 communities with >25% S. mansoni infection rates in comparison with the 17 other villages and ezbas. Transmission of S. mansoni is focally well established in Fayoum, which also has the highest prevalence of S. haematobium in the governorates surveyed by the Epidemiology 1, 2, 3 Project. However, both urinary tract and hepatic morbidity are relatively rare in the governorate. This probably results from the long-standing schistosomiasis control program in Fayoum, which suppressed intensity more than prevalence of infection, leading to less community morbidity.

Parasite density and malaria morbidity in the Pakistani Punjab

The relationship between quantitative Plasmodiumfalciparum or P. vivax parasitemia and clinical illness has not been defined in Pakistan or in other areas where malaria transmission is not highly endemic. Standardized questionnaires were given to and physical examinations and parasitologic tests were performed in 8,941 subjects seen in outpatient clinics in 4 villages for 13 consecutive months in the Punjab region of Pakistan. The results, based on multivariable analysis, showed that a clinical diagnosis of malaria, a history of fever, rigors, headache, myalgia, elevated temperature, and a palpable spleen among children were all strongly associated with the presence and density of P. falciparum or P. vivax malaria in a monotonic dose-response fashion. The malaria attributable fraction of a clinical diagnosis of malaria, and the same symptoms and signs also increased with increasing P. falciparum and, to a lesser extent, P. vivax, parasitemia. Unlike in sub-Saharan Africa, clinical illness due to malaria often occurs in the Punjab among adolescents and adults and in patients with parasite densities less than 1,000/microl. Clinical guidelines based upon parasitemia and symptomatology must be adjusted according to the intensity of transmission and be specific for each geographic area.

Incidence rates of Lyme disease in Maryland: 1993 through 1996

The incidence rate per 100,000 population by gender and age group was calculated for the 24 Maryland jurisdictions using 1,392 cases reported to the Lyme Disease Registry during 1993 to 1996. The overall incidence rate for the state was 7.0 cases per 100,000 inhabitants. Males (incidence rate = 7.7) were 1.2 times more affected than females (incidence rate = 6.2) (p < 0.001). The bimodal overall age distribution shows a peak in the 10 to 19 age category (incidence rate = 8.5) and in the 50 to 59 age group (incidence rate = 8.9), and in the 20 to 29 age group (incidence rate = 3.9). The incidence rate by jurisdiction ranged from 0.7 in Allegany County from Western Maryland to 88.3 in Kent County on the Upper Eastern Shore. Results from this study show that counties from the Upper Eastern Shore region had the highest specific incidence rate by age group/gender/jurisdiction while counties from Western Maryland had the lowest specific incidence rates and have not reported Lyme disease patients younger than 10 or older than 59 years of age. This difference might be explained primarily by the kind of outdoor activities in which the different age groups are involved and the relative abundance of Ixodes scapularis infected with the etiologic agent of Lyme disease, Borrelia burgdorferi, in these two regions.

Comparison of tests for antibody to hepatitis E virus

The results of serologic tests for hepatitis E virus have varied widely from laboratory to laboratory, making interpretation of seroepidemiologic studies difficult. The present study compares serologic results with different antigens and tests developed in two laboratories for their ability to diagnose hepatitis E and measure antibody prevalence in a high risk population in Saudi Arabia. The results confirm that tests based upon open reading frame (ORF) 3 of HEV are of limited value for seroepidemiologic studies, whereas ORF2-based antigens have broad utility and yield data that are reproducible in more than one laboratory.

Ultrasound-detected hepatic periportal thickening in patients with prolonged pyrexia

Hepatic periportal thickening (HPT) detected by ultrasonography has been established as a reliable tool for measuring hepatic morbidity due to schistosomiasis. During ultrasonographic examination of patients with prolonged pyrexia, we frequently noticed minimal grades of HPT in patients without a history of schistosomiasis. This led to ultrasonographic studies of conditions other than schistosomiasis in which HPT may occur. Subjects included 460 patients with Schistosoma haematobium infection, 107 urban patients with prolonged pyrexia without previous exposure to schistosomiasis, and 288 healthy controls unexposed to schistosomiasis. Grade I HPT was more prevalent (P < 0.001) in patients with pyrexia (56.1%) than in those with S. haematobium (32.2%) and was more frequent (P < 0.001) in patients with S. haematobium than in controls (11.1%). Typhoid fever was the most common febrile illness causing HPT. Grade II lesions were rare in patients with pyrexia (2.8%) or schistosomiasis (0.9%). Grade III lesions were present in only one patient with S. haematobium. Mild grades of HPT can occur in infectious diseases other than schistosomiasis. Cellular infiltration in the portal tract from chronic infectious diseases can frequently give the ultrasonographic appearance of grade I HPT.

Tick bites and Lyme disease in an endemic setting: problematic use of serologic testing and prophylactic antibiotic therapy

CONTEXT

The use of serologic testing to diagnose Lyme disease (LD) is a source of controversy. Expert recommendations also discourage the routine use of antibiotic therapy for prophylaxis of LD following tick bites, but the extent to which physicians in endemic areas have adopted these recommendations is not known.

OBJECTIVE

To assess the pattern of use of serologic testing and antibiotic therapy for tick bites and LD and associated charges for management in an endemic area.

DESIGN

Active surveillance of patient-physician encounters for tick bites and LD.

SETTING

Primary care practices on the Eastern Shore of Maryland.

PATIENTS

Consecutive sample of 232 patients with tick bites, LD (defined by physician diagnosis in medical record), and suspected LD (physician notation of possible, but not definite LD) seen in 1995.

MAIN OUTCOME MEASURES

Serologic testing for LD, test results, antibiotic therapy, and direct costs of management.

RESULTS

Surveillance identified 142 patients (61.2%) with diagnoses of tick bites, 40 patients (17.2%) with LD, and 50 patients (21.6%) with suspected LD. Of the 142 patients seen for tick bites, 95 (67%) underwent serologic testing for LD. Of these, 93 patients had initial negative or equivocal results; 24 (26%) of the 93 had convalescent testing, with 1 seroconversion. Seventy-eight patients (55%) with a diagnosis of tick bite received antibiotic therapy. No patients with tick bite developed clinical LD. Serologic testing for LD was performed for 36 patients (90%) with a diagnosis of LD and 46 patients (92%) with suspected LD. In most cases, antibiotics were prescribed before serologic test results became available. Convalescent testing was not performed for 37 (86%) of the 43 patients with suspected LD who had initial negative or equivocal results. Of these 37 patients, 25 (68%) did not receive antibiotic therapy. Direct charges for treatment of these 232 patients totaled $47 595, one third of which was attributable to serologic testing. A total of 32% of direct charges were for patients with tick bites, 48% were for patients with LD, and 20% were for patients with suspected LD.

CONCLUSIONS

In this setting, most patients consulting physicians for tick bites received prophylactic antibiotic therapy of unproven efficacy and underwent unnecessary, costly serologic testing. Despite almost universal use in this study, serologic testing for LD did not appear to influence treatment of patients diagnosed as having LD.

Determinants of infection with schistosomiasis haematobia using logistic regression

A population-based stratified random sample of 10,039 inhabitants of rural communities in Minya Governorate, Egypt, were evaluated for risk factors for Schistosoma haematobium infection using multivariate analysis. Data were obtained by personal interview recording demographics, information on exposure to canal water, history of infection, and other risk factors for infection and examining urine samples for S. haematobium ova. Logistic regression analysis was used to adjust for confounders while assessing the role of each risk factor for infection. Using logistic regression allowed detection of several confounders and interactions which influenced other independent variables. Differences in exposure patterns to canal water among age and gender subgroups explained only a small portion of the variation in infection rates, thus favoring the alternative explanation: development of age-acquired immunity. The association of age with reduced prevalence of S. haematobium was the only relationship increasing (odds ratio [OR] = 2.95-4.30) with logistic regression. Male gender was a risk factor for infection but did not increase with logistic regression (OR = 2.33-2.03). The protective effects of education, only noted in schoolage children (OR = 0.59-0.51), were believed to be due to a school-based screening and treatment program.

Hematuria and proteinuria as predictors of Schistosoma haematobium infection

An investigation of a population-based stratified random sample of 11,970 inhabitants of Minya Governorate in Egypt included examining urine specimens for Schistosoma haematobium ova using the filtration technique and for hematuria and proteinuria using reagent strips. Age- and gender-specific sensitivity, specificity, predictive values, and likelihood ratios of reagent strip-detected hematuria and proteinuria as indicators of S. haematobium infection were assessed. Results showed that in this population with a 9.0% infection rate, sensitivity (from 45.9 to 70.9) and specificity (from 65.9 to 86.3) were much lower than in previous reports. The most clinically valuable parameters, positive predictive value (PPV), negative predictive value (NPV) and likelihood ratio (LR), were highest with the presence of hematuria > or = +++ and proteinuria > or = ++, especially in males less than 20 years of age. Using the LR allowed effective altering of the pretest probability of infection among age and gender subgroups. The study concluded that reagent strip-detected hematuria and proteinuria, although valuable, are less reliable predictors of S. haematobium within communities than previously reported and their usefulness is improved with stratification by age and gender. In addition, predictive values and likelihood ratios provide practical information for predicting the presence or absence of infection within population subgroups.

Utilization and cost of serologic tests for Lyme disease in Maryland

To ascertain use of serologic tests for Lyme disease (LD) in Maryland, all laboratories registered with the State Health Department were surveyed. Results show that from 1992 to 1995, 17 laboratories performed 100,000 serologic tests costing $7.1 million on Maryland residents; 90% of these tests were EIAs. The proportion of positive EIAs increased from 3.4% in 1992 to approximately 7.0% in 1994 and 1995, and the percentage of positive second tests (Western blot, WB) fell from 7.9% to 5.0%-5.5%. The large number of EIAs performed in comparison with the low incidence of LD in the state results in a low predictive value of a positive EIA test. Therefore, the WB is indicated to confirm equivocal and positive EIA tests when characteristic clinical findings of LD are not present. The 30,000 tests for LD performed annually on Maryland residents at a cost of over $2 million in direct medical costs must be added to the public health burden of LD in this state.

Evaluation of an ultrasonographic score for urinary bladder morbidity in Schistosoma haematobium infection

An ultrasonographic urinary bladder morbidity score was developed and tested in 510 patients with schistosomiasis haematobia, and then evaluated for screening 1,134 randomly selected children from villages endemic for Schistosoma haematobium. The ultrasonographic urinary bladder morbidity score had four grades ranging from normal to marked thickening of the urinary bladder wall or any polyps or masses. Among both patients and randomly screened subjects, the ultrasonographic score was greater (P = 0.01 and P < 0.01) in males than in females. Children examined in the clinic had higher (P = 0.03) ultrasonographic scores than adults. Infected subjects in communities were more likely (P < 0.001) to have urinary bladder morbidity than uninfected subjects, and clinic patients with egg counts > or = 20 eggs/10 ml of urine had higher (P = 0.03) ultrasonographic urinary bladder morbidity scores than those with lighter infections. The geometric mean egg count was higher (P = 0.04) in clinic patients with grade II and III lesions than in those with grade 0 and I lesions. There was progressive improvement of the grade of urinary bladder morbidity scores in patients treated with praziquantel at each follow-up examination (P < 0.001) and there was a positive relationship (P < 0.01) between urinary bladder morbidity scores and ultrasonographic-detected renal back pressure changes. The ultrasonographic urinary bladder morbidity score objectively measured the severity of urinary bladder morbidity and correlated with intensity of S. haematobium infection in our subjects. It can be used in evaluating both morbidity in patients and in community surveys and in following the outcome of chemotherapy.

Comparative evaluation of the use of artificial neural networks for modelling the epidemiology of schistosomiasis mansoni

There has been a marked increase in the application of approaches based on artificial intelligence (AI) in the field of computer science and medical diagnosis, but AI is still relatively unused in epidemiological settings. In this study we report results of the application of neural networks (NN; a special category of AI) to schistosomiasis. It was possible to design an NN structure which can process and fit epidemiological data collected from 251 schoolchildren in Egypt using the first year's data to predict second and third years' infection rates. Data collected over 3 years included age, gender, exposure to canal water and agricultural activities, medical history and examination, and stool and urine parasitology. Schistosoma mansoni infection rates were 50%, 78% and 66% at the baseline and the 2 follow-up periods, respectively. NN modelling was based on the standard back-propagation algorithm, in which we built a suitable configuration of the network, using the first year's data, that optimized performance. It was implemented on an IBM compatible computer using commercially available software. The performance of the NN model in the first year compared favourably with logistic regression (NN sensitivity = 83% (95% confidence interval [CI] 78-88%) and positive predictive value (PPV) = 63% (95% CI 57-69%); logistic regression sensitivity = 66% (95% CI 60%-72%) and PPV = 59% (95% CI 53%-65%). The NN model generalized the criteria for predicting infection over time better than logistic regression and showed more stability over time, as it retained its sensitivity and specificity and had better false positive and negative profiles than logistic regression. The potential of NN-based models to analyse and predict wide-scale control programme data, which are inevitably based on unstable egg excretion rates and insensitive laboratory techniques, is promising but still untapped.

Plasmodium falciparum circumsporozoite vaccine immunogenicity and efficacy trial with natural challenge quantitation in an area of endemic human malaria of Kenya

It has been hypothesized that antibody induced by Plasmodium falciparum circumsporozoite protein vaccine would be effective against endemic human malaria. In a malaria endemic region of Kenya, 76 volunteers, in 38 pairs sleeping adjacently, were immunized with subunit circumsporozoite protein Asn-Ala-Asn-Pro tetrapeptide repeat-pseudomonas toxin A, or hepatitis B vaccine. After quinine and doxcycycline, volunteers were followed for illness daily, parasitemia weekly, antibody, T-lymphocyte responses, and treated if indicated. Anopheles mosquitoes resting in houses were collected, and tested for P. falciparum antigen, or dissected for sporozoites and tested for blood meal ABO type and P. falciparum antigen. Vaccine was safe, with side-effects similar in both groups, and immunogenic, engendering IgG antibody as high as 600 micrograms ml-1, but did not increase the proportion of volunteers with T-lymphocyte responses. Estimation of P. falciparum challenge averaged 0.194 potentially infective Anopheles bites/volunteer/ day. Mosquito blood meals showed no difference in biting intensity between vaccine and control groups. Both groups had similar malaria-free survival curves, cumulative positive blood slides, cumulative parasites mm-3, and numbers of parasites mm-3 on first positive blood slide, during three post-vaccination observation periods. Every volunteer had P. falciparum parastemia at least once. Vaccinees had 82% and controls 89% incidences of symptomatic parasitemia (P = 0.514, efficacy 9%, statistical power 95% probability of efficacy < 50%). Vaccine-induced anti-sporozoite antibody was not protective in this study. Within designed statistical precisions the present study is in agreement with efficacy studies in Colombia, Venezuela and Tanzania.

The public health impact of Lyme disease in Maryland

The purpose of this study was to estimate the health burden imposed by Lyme disease (LD) in Maryland during 1992 and 1993. A cross-sectional 1-in-15 survey of physicians (total, 1200) in Maryland was conducted to estimate the incidence of diagnosed LD, presumptive cases of LD, patients with tick bites, and diagnostic tests ordered for LD. Results show that LD is underreported by 10- to 12-fold in Maryland, that 80% of cases are managed by primary care physicians, and that there is discordance between the actual clinical treatment of patients and the recommended approach. In addition, the much greater numbers of patients treated for presumptive LD, seen and given prophylaxis for tick bites, and having diagnostic tests indicate that real and perceived LD is a far greater public health problem and uses more medical resources than official surveillance data suggest.

Lyme disease surveillance in Maryland, 1992

The incidence of Lyme disease (LD) reported to the Maryland Department of Health and Mental Hygiene during 1992 was 6.5/100,000 population, ranging from 29.3 cases/100,000 on the Eastern Shore (74.4% of all cases) to no cases in the mountains of western Maryland. Among the 317 reported patients, 44.4% gave a history of tick exposure and 78.9% had positive serologic test results. For the 187 (59.0%) patients meeting the Centers for Disease Control and Prevention (CDC) surveillance case definition, erythema migrans (EM) occurred in 69.5%, with arthritic (26.7%), neurologic (13.4%), and cardiac (2.1%) manifestations being less frequent. Patients not meeting the surveillance case definition were significantly more likely to have influenza-like symptoms, a smaller rash, and arthralgia. Patients meeting the CDC criteria were more likely to have an onset during the major transmission season in the summer (odds ratio (OR): 2.1; confidence interval (CI): 1.2 to 3.6) since this was the time when most (115/130) patients with EM were detected. Positive serologic results were more likely (OR: 2.2; CI: 1.2 to 4.2) in those not meeting the case definition. The treatment given to patients thought to have LD was almost always that recommended in the literature and there was no difference between treatment prescribed for patients meeting and those not meeting the case definition. These data show that physicians in Maryland are treating many patients for LD who are clinically diagnosed as having LD (e.g., febrile patients with flulike symptoms, patients with arthralgias or erythematous rashes < 5 cm in size) and who have positive serologic test results but who do not meet the CDC surveillance case definition. These patients and the large number of unreported patients being seen and treated for LD or tick bites must be added to the overall burden of LD in the state.

Diagnosis and treatment of hepatic hydatid cysts with the aid of echo-guided percutaneous cyst puncture

The usefulness of echo-guided percutaneous cyst puncture in the diagnosis and treatment of hepatic hydatid cysts was assessed in a study of 45 patients referred to the Department of Tropical Medicine at Kasr El Aini Hospital in Cairo. All subjects had at least one hepatic cyst detected by ultrasonography (54 cysts in all), and 42 patients had positive results in serological tests for antibodies to Echinococcus granulosus. The majority of cysts were in the right hepatic lobe (40 cysts), were anechoic (51), and were rounded and smooth (49). All 45 active cysts (44 anechoic, rounded, and smooth; one anechoic and septated) yielded clear watery fluid containing scolices and exhibited elevated pressure on percutaneous puncture. In contrast, all nine inactive cysts yielded cloudy yellowish fluid without detectable scolices and did not display elevated pressure on puncture. The latter cysts were anechoic and elliptical (two cysts); anechoic and septated (one); anechoic with a calcified wall (one) or a detached germinal layer (two); or rounded with coarse echoes (three). Treatment by injection of a scolicidal agent (hypertonic saline) before withdrawal of the needle used for aspiration gave excellent results and was not associated with complications. Forty-three of the 45 patients had no clinical or ultrasonographic evidence of recurrent or new hepatic cysts after 3 years of follow-up.

High prevalence of hepatitis C in Egyptian patients with chronic liver disease

The highest prevalence rates of hepatitis C virus infection in the world have been recently reported among Egyptian blood donors and frequent recipients of transfusions and other blood products. This is the first report, however, demonstrating hepatitis C as the most frequent association with chronic liver disease in Egypt. Of 1023 patients referred to the Liver Institute in Menoufia governorate for evaluation of chronic liver disease, 752 (73.5%) had antibodies to hepatitis C compared with 168 (16.4%) with hepatitis B surface antigen. Hepatitis C antibody was more common in patients with active schistosomiasis and patients without hepatitis B surface antigenaemia. Of 100 patients having liver biopsies, histological findings consistent with chronic viral hepatitis or its complications were found in 89 and antibody to hepatitis C was present in 75 (84.3%) of these patients with chronic hepatitis, active cirrhosis or hepatocellular carcinoma. These data pointing to the importance of hepatitis C as a cause of chronic liver disease in Egypt emphasise the necessity of studies delineating its routes of transmission in this country.

High seroprevalence of hepatitis C infection among risk groups in Egypt

High prevalence rates of hepatitis C virus (HCV) were recently reported among Egyptian blood donors. To confirm these observations and estimate the magnitude of HCV infection in this country, we determined the prevalence of antibodies to HCV (anti-HCV) in samples collected in 1992 from seven different populations of children and adults living in Egypt. Anti-HCV was found in 12.1% of rural primary schoolchildren, 18.1% of residents of a rural village, 22.1% of army recruits, 16.4% of children with hepatosplenomegaly, 54.9% of hospitalized, multitransfused children, 46.2% of adults on hemodialysis, and 47.2% of adults with chronic liver disease or hepatoma. Age-related prevalence of anti-HCV in a random sample of 270 inhabitants of a rural village increased progressively from zero in those 5-10 years of age to 41% in adults greater than the age of 50. Although the increased prevalence of anti-HCV among children and adults with parenteral exposures and chronic liver disease was expected, the prevalence of anti-HCV among persons representing the general population of Egypt was strikingly high. These data demonstrate the magnitude of HCV infection and its importance in chronic liver disease in Egypt. Future studies are needed to determine the routes of transmission of HCV in this country.

Gastrointestinal manifestations of schistosomiasis

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Maryland physicians' survey on Lyme disease

In a survey of 252 physicians practicing in Maryland, 170 responders diagnosed 142 cases of Lyme disease (LB) during 1990 and 1991. About 80% of the cases were diagnosed by primary care physicians. The most common clinical finding, erythema migrans (EM), was reported in half the cases and arthritis was reported in a quarter. Only 22.2% had a history of a tick bite; serological tests were ordered in a third of the cases. EM was treated with oral antibiotics for 10-21 days. Most physicians treated Lyme arthritis with the same therapy, although some used intravenous ceftriaxone. The most commonly used treatment for neurologic or cardiac complications was intravenous ceftriaxone. These preliminary data suggest that LB may be diagnosed by Maryland physicians more frequently than syphilis and tuberculosis. The data also indicate LB is a much larger problem in Maryland than suggested by official reports to the Centers for Disease Control. The clinical characteristics of the illness and the antibiotics prescribed for it in Maryland are similar to those reported in northeastern states.

Antibiotic therapy for Lyme disease in Maryland

The recommended treatment of Lyme disease is evolving and important questions remain unanswered, such as (a) Are inexpensive oral regimens effective in curing acute illness and preventing arthritic, neurologic, and cardiac manifestations or are much more costly, and potentially toxic, intravenous antibiotics required? (b) Are relatively short 2- to 3-week courses of antibiotics sufficient or are prolonged regimens of a month, or more, better? This study reviews antibiotic therapy prescribed by Maryland physicians for the 283 cases reported in 1991 that meet the Centers for Disease Control and Prevention's case definition for Lyme disease. The purpose of the review was to obtain baseline information on the antibiotics being used by physicians in practice to treat patients that they believe have Lyme disease. The most frequently prescribed antibiotics for either the 60 percent of patients presenting with erythema migrans or the 40 percent with arthritic, neurologic, or cardiac manifestations were oral doxycycline (47 percent), tetracycline (11 percent), and amoxicillin (13 percent). Seventy-one percent of therapeutic courses were for 2 to 3 weeks. Amoxicillin was used in two-thirds of children younger than 8 years. Sixty (21 percent) received intravenous therapy, of which ceftriaxone, with or without other antibiotics, was almost always (95 percent) used. Intravenous therapy was more frequently given to those with arthritic, neurologic, and cardiac manifestations than to those with erythema migrans (odds ratio = 3.7) and to those with these systemic symptoms along with erythema migrans than to those with erythema migrans alone (odds ratio = 3.8). The average course was 2 days longer in treating those with arthritic, neurologic, or cardiac manifestations than in treating those with erythema migrans alone(P = 0.05).An epidemiologic assessment of antibiotics prescribed by the physicians in Maryland to treat Lyme disease in 1991 shows the choices, dosage, and duration of drugs generally followed those most frequently recommended in the literature. Also, it shows that efforts to educate physicians should be directed more towards the diagnosis rather than the treatment of Lyme disease.

Is Schistosoma mansoni replacing Schistosoma haematobium in the Fayoum?

Schistosoma mansoni is progressively replacing S. haematobium along the Nile River in Egypt. This change has occurred in the past 15-20 years following construction of the Aswan High Dam in the 1960s. The cause is a shift in relative abundance of the snail vectors Biomphalaria alexandrina and Bulinus truncatus. Biomphalaria is increasing while the latter has disappeared from a village in the Fayoum where formerly only schistosomiasis haematobia was endemic. A cross-sectional household survey in this village in 1991 showed the following prevalence values: S. mansoni, 22.3%; S. haematobium, 3.4%; and mixed infections, 2.8%. Only two children less than 10 years of age had S. haematobium infections. A review of the local Ministry of Health records showed that 1) both species were parasitologically diagnosed during the past 7.5 years, 2) Biomphalaria had been abundantly present in the local waterways for the past 10 years and has been found infected with S. mansoni since 1985, 3) Bulinus has not been detected in the local canals and drains since 1986 and the few found between 1981 and 1985 were not infected, and 4) Biomphalaria in this village and in two others in the Fayoum were believed infected by laborers from the Delta who helped build schools in 1984. This change in the distribution of schistosomiasis will impact upon public health and medical practice in Middle and Upper Egypt as it already has in Lower Egypt.

Foci of Schistosoma mansoni in Assiut province in middle Egypt

Following detection of Schistosoma mansoni in a 12 years old boy who had both schistosomal polyposis and periportal fibrosis with hepatosplenomegaly, epidemiological studies to confirm local transmission were performed in his and 30 other villages in Assiut Governorate, Egypt. The index case's brother and 6 of 380 inhabitants of his village who provided stool specimens were infected with S. mansoni and a farmer with dysentery and hepatosplenomegaly had a positive rectal snip biopsy. All had hepatic abnormalities on ultrasound examination. Two of 221 schoolchildren in another village had mixed infections with S. mansoni and S. haematobium; 17 others had only S. haematobium. None of 419 inhabitants living near the infected boys had S. mansoni infection. Snails from canals and drains near both villages were netted, identified, counted and checked for infection: in the second village one of 1039 Bulinus truncatus was infected with Schistosoma sp. but none of 859 Biomphalaria alexandrina was infected. Schistosomiasis mansoni is being focally transmitted in 2 villages in Assiut Governorate and appears to be spreading from Lower to Middle and Upper Egypt. We believe B. alexandrina, which has been present in some of the waterways for at least 15 years, were infected recently by local inhabitants returning from Iraq or by cattle traders or military recruits from the Delta.

Ultrasonographic prediction of esophageal varices in Schistosomiasis mansoni

Bleeding from esophageal varices is a common and serious problem in Schistosomiasis mansoni. A simple and accurate method of detection would facilitate measurement of individual and community morbidity and allow institution of preventive measures. An ultrasonographic scoring system grading periportal fibrosis, portal vein diameter, spleen size, and portasystemic anastomoses was evaluated as a predictor of esophageal varices and a past history of upper gastrointestinal hemorrhage in 43 patients with hepatosplenic schistosomiasis. Ultrasonographic variceal score correlated (r = 0.86, p < 0.001) with the endoscopic variceal grade. Patients with a sonographic score of 5 or greater were highly likely (21 of 23) to have varices of grade II or greater (sensitivity, 91.3%; specificity, 94.7%). Only those with sonographic scores of 5 or greater (15 of 23) had bled from esophageal varices. The ultrasonographic score provided a simple, inexpensive, accurate, and noninvasive means of screening individuals with hepatosplenic schistosomiasis for esophageal varices, and correlated strongly with prior gastrointestinal hemorrhage. It is not known whether a similar score would be useful in hepatic cirrhosis.

Abdominal ultrasonography for assessing morbidity from schistosomiasis. 2. Hospital studies

Abdominal ultrasound, which uses a pulse echo device to record reflected waves of a sound beam in 2 dimensions, has revolutionized the evaluation of schistosomal morbidity. It is relatively inexpensive, rapid, simple to perform and portable, causes no biological hazards to the subject and, because of its speed, is ideal for diagnosis and directing interventions, e.g., biopsies. Ultrasound complements or replaces intravenous pyelography, cystoscopy, endoscopy, liver biopsy, angiography and other invasive techniques for studying morbidity due to schistosomiasis. The sensitivity and specificity of ultrasound, in comparison to these other procedures, for detecting schistosomal lesions has been between 80% and 100%, with the exception of detection of hydroureter, ureteral calculi and calcified bladder. Ultrasound is the best method for measuring liver and spleen size and configuration; detecting and grading periportal fibrosis, portal hypertension, hydronephrosis and urinary bladder wall lesions; and for demonstrating renal and bladder stones.

Abdominal ultrasonography for assessing morbidity from schistosomiasis. 1. Community studies

Portable abdominal ultrasonography has been used to measure community morbidity from schistosomiasis in schoolchildren and cross-sectional population samples and to assess efficacy of chemotherapy. Periportal fibrosis and hepatosplenomegaly have been common findings, usually associated with each other and with prevalence and intensity of infection as measured by faecal Schistosoma mansoni ova excretion. Similar, less severe, lesions have been noted in subjects infected with S. haematobium. Inhabitants of villages where praziquantel therapy was systematically provided had less periportal fibrosis and hepatosplenomegaly than those living in nearby villages where treatment was not available. Community-based screening in S. haematobium endemic areas has shown high prevalence of bladder wall thickening, irregularities, and polyps which were usually more frequent and severe in children and in those excreting most ova. Obstructive uropathy was frequent in most studies. Chemotherapy usually rapidly resolved the bladder wall abnormalities. In some studies hydronephrosis and hydroureter were more persistent. Reversibility of chronic, stable lesions in adults remains unproven.

Fever in the returned traveler

Febrile infections can be fatal in travelers to tropical countries unless the patient seeks medical care in a timely manner and the physician takes the time and has the skill to make a rapid diagnosis and prescribe appropriate therapy. In addition to the usual febrile illnesses present in temperate climates, the patient may have an "exotic" infection, e.g., malaria, infectious hepatitis, enteric fever, or dengue fever. The potential causes of fever in travelers are extensive. This article provides practical clues to assist the physician in making the correct diagnosis--by using exposure information, symptoms and signs, and concomitant symptom complexes.

Tuberculous peritonitis in Egypt: the value of laparoscopy in diagnosis

Abdominal laparoscopy was performed on 200 patients with undiagnosed ascites. It was unsuccessful in one patient with tuberculous peritonitis because of extensive adhesions. A presumptive diagnosis of tuberculous peritonitis based on clinical findings and peritoneal tubercles or adhesions visualized during laparoscopy was made in 90 of these patients. The diagnosis was confirmed in 88 by histopathology, bacteriology, or therapeutic response. Two of the 109 remaining patients who had other presumptive diagnoses made during laparoscopy were eventually confirmed to be cases of tuberculous peritonitis. Of 91 patients with tuberculous peritonitis included in this series, 79% were females, with the majority (79%) of them being of child-bearing age. Half had been ill for longer than one month. The most frequent complaints were abdominal pain, fever, anorexia, night sweats, abdominal swelling, and weight loss. Ascites, fever, wasting, pallor, and abdominal tenderness were common findings. Ultrasonography demonstrated ascites in all patients who underwent this procedure; 21% also had adhesions. Pleural effusion was present in 15% and pulmonary tuberculosis was detected in only two patients. Biopsy samples taken during laparoscopy showed that 60% had noncaseous granulomas and 33% had caseous granulomas. Mycobacterium tuberculosis was detected in 77%, with guinea pig inoculation having the highest sensitivity, followed by culture, and lastly by acid-fast smear. Mycobacterium tuberculosis was isolated more easily from biopsy samples than from ascitic fluid. Nine of 20 M. tuberculosis isolates that were identified as to species were M. bovis. Tuberculous peritonitis, a frequent cause of febrile ascites in Egyptian women, was easily diagnosed by histopathologic and bacteriologic studies of biopsy samples taken at laparoscopy. All patients responded rapidly to antituberculosis therapy.

Efficacy of hepatitis B vaccination in primary school children from a village endemic for Schistosoma mansoni

To determine whether chronic Schistosoma mansoni infection interferes with hepatitis B virus (HBV) immunization, 308 schoolchildren aged 6-12 years with no evidence of prior HBV infection (156 with active schistosomiasis) were vaccinated with three 5-micrograms injections of recombinant DNA-derived HBV vaccine. The vaccine was given in the deltoid muscle at time 0 and 1 and 7 months later. All vaccinees were examined 1 and 3 years after vaccination for quantitative antibody to hepatitis B surface antigen (anti-HBs). Seroconversion was detected in 284 vaccinated children (92%), of whom 271 had a good (51-300 mIU/mL) or excellent (greater than 300 mIU/mL) anti-HBs response. Sixteen other children (5%) had evidence of natural HBV infection (antibody to hepatitis B core antigen). Of those with good or excellent response, 99% retained high antibody titers for 3 years. Response was not influenced by S. mansoni infection. Hepatomegaly and splenomegaly were associated with reduced vaccine response.

Ultrasonographic changes of the liver in Schistosoma haematobium infection

Abdominal ultrasonographic examination was performed in 61 hospitalized patients with chronic liver diseases and 253 school children from a village endemic for Schistosoma haematobium and were compared with 142 urban children without exposure to Schistosoma. The prevalence of ultrasound-detectable hepatomegaly and splenomegaly and the degree of periportal fibrosis was compared between those with and without S. haematobium infection. Among 13 patients with biopsy-proven schistosomal hepatic fibrosis, three with coarse changes secondary to S. mansoni infection showed grade III periportal fibrosis, while 10 patients with fine schistosomal hepatic fibrosis due to S. haematobium had borderline (two) or grade I (eight) changes. Ultrasound evidence of periportal fibrosis was not detected in patients with hepatic cirrhosis, chronic active hepatitis, or fatty infiltration. However, three of 14 patients with chronic persistent hepatitis had grade I periportal fibrosis and two had borderline changes. The frequency of ultrasound-detected hepatomegaly and splenomegaly was greater among rural S. haematobium-infected children (35.2% and 22.4%, respectively) than among noninfected rural (21.1% and 13.3%) and urban (16.9% and 4.9%) children. Also, the frequency of grade I periportal fibrosis was significantly greater (P less than 0.01) in S. haematobium-infected children (22.4%) than in noninfected rural (11.7%) and urban (0.7%) children. No patients with S. haematobium infections, either in the hospital or the village, had grade II or III periportal fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)