Predictors of mortality in patients with pyogenic liver abscess.

BACKGROUND: Pyogenic liver abscess (PLA) is uncommon but potentially life-threatening. The objective of this study was to identify the prognostic factors for PLA. METHODS: The medical records of 253 patients, 148 men and 105 women with a mean age of 56.4 years (SD : 15.0 years), who were hospitalised due to a PLA between January 1995 and June 2007 were reviewed. The underlying medical disorders, clinical signs and symptoms, laboratory values, imaging studies, microbiological features, treatments, morbidity and mortality were recorded. Factors related to in-hospital case fatality were analysed. RESULTS: The mean Acute Physiology And Chronic Health Evaluation (APACHE) II score at admission in patients with PLA was 8.7 points (SD 5.4 points). The most common co-existing disease was diabetes mellitus (41.9%), followed by biliary stone disorders (32.0%). Klebsiella pneumoniae was the most frequent pathogen, followed by Escherichia coli. The in-hospital case-fatality rate was 9.1%. Multivariate analysis revealed that gas-forming abscess (p=0.019), multi-drug resistant isolates (p=0.026), anaerobic infection (p=0.045), blood urea nitrogen level >7.86 mmol/l (p=0.004), and APACHE II score > or =15 (p= 0.004) were associated with mortality. CONCLUSIONS: The prognosis of PLA may depend chiefly on the severity of the basic physical condition and underlying pathology. As the primary treatment for PLA is not completely effective, a more aggressive approach should be considered, especially for patients with poor prognosis.

Seroprevalence of hepatitis C virus infection and its association with natural infection of hepatitis B virus among preschool children in Taiwan.

Taiwan is a hyperendemic area of hepatitis B virus (HBV) infection where chronic hepatitis B is the most important cause of liver cirrhosis and hepatoma. Since, diagnostic kit for detecting hepatitis C virus (HCV) infection has been developed, HCV was found to be another important etiology of chronic liver disease. In order to study the seroprevalence of HCV infection among preschool children after mass hepatitis B vaccination program in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and two aboriginal areas randomly selected through stratified sampling. Serum specimens of 2538 preschool children were screened for the HCV antibodies (anti-HCV) by a commercially available third-generation microparticle enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (ORm) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. A total of 58 children were anti-HCV seropositive, giving a prevalence of 2.3%. The prevalence of anti-HCV was 1.0% (5 of 484) among aboriginal children, a significantly decreased seroprevalence compared with those among other ethnic groups after multivariate adjustment. Boys had a higher anti-HCV seroprevalence, but not statistically significantly different from girls (ORm: 1.6; 95% CI: 0.9-2.8; p = 0.08). The seroprevalence of the age group of 3-4 years was lower than that of the age group of 5-6 years (ORm: 2.2; 95% CI: 1.1-4.2; p = 0.02). After multivariate adjustment, preschool children with natural HBV infection had a higher anti-HCV seroprevalence, but not statistically significantly different from those without natural HBV-infection (ORm: 2.6; 95% CI: 0.9-7.4; p = 0.08 for HBV-infected vs. uninfected). HCV infection varies with gender, residential area, and natural HBV infection. HCV and HBV might share common transmission routes in Taiwan.

Current seroprevalence of hepatitis A virus infection among kindergarten children and teachers in Taiwan.

Taiwan was a hyperendemic area for hepatitis A virus (HAV) infection before the late 1980s. The seroprevalence of HAV infection was higher than 90% with most HAV infection occurring during childhood. This study was to estimate the seroprevalence of HAV infection among preschool children in central Taiwan. A community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas and 2 aboriginal areas randomly selected through stratified sampling. Serum samples of 2,549 healthy preschool children and 104 teachers in study kindergartens were screened for the HAV antibodies (anti-HAV) by means of a commercially available microparticle enzyme immunoassay (AxSYM HAVAB). Among aboriginal kindergarten children, more than 96% of them were anti-HAV seropositive due to a mass HAV vaccination program. In urban and rural areas, kindergarten children had a very low prevalence of anti-HAV (0.4%) in contrast to a high seroprevalence in their teachers (78%). There was no gender difference in seroprevalence of anti-HAV, while the anti-HAV seroprevalence was significantly higher in urban areas than in rural areas. Crowdedness of living in urban areas might facilitate the person-to-person transmission of infectious agents.

Association between seropositivity of antibodies against hepatitis a virus and Helicobacter pylori.

Helicobacter pylori and hepatitis A virus (HAV) are documented to share common transmission routes including fecal-oral. This study examined the association between seropositivity of antibodies against H. pylori (anti-HP) and HAV (anti-HAV) via a community-based survey of 40 randomly selected kindergartens in 10 urban and 10 rural areas. Serum samples from 2,047 healthy preschool children and 104 teachers were screened for anti-HP by enzyme-linked immunosorbent assay, and for anti-HAV by microparticle enzyme immunoassay. In children, a low prevalence of anti-HAV (0.44%) was found, in contrast to a high prevalence in their teachers (78.8%); anti-HP seroprevalence was 6.4% for children and 30.8% for teachers. Anti-HAV and anti-HP seropositivities were significantly associated in teachers after adjustment for age, sex, and residential area through multiple logistic regression analysis (multivariate-adjusted odds ratio = 7.3; 95% confidence interval [CI] = 1.4-36.8, P < 0.001). Our findings suggest that HAV and H. pylori may have shared transmission routes in central Taiwan 15 years or more ago, but not any recently.

Seroepidemiology of Helicobacter pylori infection among preschool children in Taiwan.

Helicobacter pylori is associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection with H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life. To examine the epidemiologic characteristics of H. pylori infection among preschool children in central Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban townships, 10 metropolitan precincts, and 2 aboriginal townships randomly selected through stratified sampling. Serum specimens of 2,551 healthy preschool children (3-6 years old) randomly sampled from study kindergartens were screened for antibodies to H. pylori by latex agglutination and ELISA methods. Multivariate-adjusted odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated by multiple logistic regression analysis. A total of 207 subjects were antibody-positive, giving a prevalence of 8.1%. The overall seropositive rates were 4.5% in 3-year-old group, 4.4% in 4-year-old group, 9.4% in 5-year-old group, and 11.7% in 6-year-old group. The older the age, the higher the seroprevalence (OR = 3.2, 95% CI = 1.5-6.8 for 3-year-old children versus the 6-year-old children). Seroprevalence was not different between boys and girls. The aboriginal townships had a seroprevalence greater than the urban townships and metropolitan precincts (OR = 2.6, 95% CI = 1.9-3.7). The larger the number of siblings, the higher the seroprevalence (OR = 2.4, 95% CI = 1.0-5.8 for those with no sibling versus those with > or = 3 siblings). In the multiple logistic regression analysis, the seroprevalence of H. pylori remained significantly increased with age, aboriginal township, and large sibship size after multivariate adjustment. A poor water supply system, sewage disposal, and other environmental hygiene in the aboriginal townships might have played some role in infection with H. pylori. The early childhood transmission among siblings might also be an important determinant of H. pylori seropositivity in Taiwan.

Tc-99m MAG3 renal studies: renogram and effective renal plasma flow in spinal cord injury patients.

To determine whether years since injury, level of injury, degree of injury, gender, or age influence renal function in 66 spinal cord injuries (SCI) patients without urological complications, individual kidney effective renal plasma flow (ERPF) and radionuclide renogram (RR) were measured using technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3). The 176 individual kidneys included 84 kidneys with normal ERPF and RR, 48 kidneys with normal ERPF but abnormal RR, and 44 kidneys with abnormal ERPF and RR. The incidence of abnormal Tc-99m renal study results was higher in the kidneys of female patients (37/54, 68%) than of male patients (55/122, 45%) (p < 0.05). We found that Tc-99m MAG3 renal studies including ERPF and RR are safe and noninvasive urological screening tests for SCI patients.

Immune status in preschool children born after mass hepatitis B vaccination program in Taiwan.

A mass hepatitis B vaccination program began in Taiwan in 1984. In order to determine the immune status of hepatitis B virus (HBV) infection among preschool children, a total of 25 kindergartens in 20 townships and metropolitan precincts in central Taiwan were randomly selected through stratified sampling. Serum specimens of 2130 healthy preschool children aged 2-6 years old were screened for the HBV markers and liver function in 1996. HBV surface antigen (HBsAg), antibody against HBsAg (anti-HBs) and antibody against HBV core antigen (anti-HBc) were tested by reverse passive hemagglutination (RPHA), enzyme immunoassay (EIA) and radioimmunoassay (RIA) using commercial kits. HBV vaccination rate of the preschool children was 98%, and complete vaccination rate (three or four doses of HBV vaccine) was 94%. The HBsAg seropositive rate was 4.5% among incomplete vaccinees and 1.3% among complete vaccinees. The anti-HBs was detectable in 1637 of 2000 complete vaccinees (81.9%) and in 53 of 88 incomplete vaccinees (60.2%). The overall prevalence rate of anti-HBc was 2.4% (52 of 2130). The older the age, the lower the anti-HBs seropositive rate. The anti-HBs seropositive rats for complete vaccinees were 100% at 2 years old and 75% at 6 years old. There were no significant differences in HBsAg-seropositive rates and anti-HBs-seropositive rates among different residential areas or ethnic groups. There were three children who were seropositive on HBsAg, anti-HBs and anti-HBc, whether they were infected by the vaccine-induced escape mutant of HBV deserves scrutiny.

Study of young women vaccinated against rubella virus for 10 years in Taiwan.

Since the licensing of the rubella virus vaccine (RA 27/3 strain) in 1979, clinical studies on the RA 27/3 strain vaccine, which gives rise to high titer antibody, have been reported. In the present study, this vaccine was used to examine the immune response in young women. Volunteers without the previous immunity to rubella virus screened by hemagglutination inhibition (HAI), latex agglutination (LA), fluorescence immunoassay (FIA) and solid-phase immunoassay (SPIA) tests were injected with Rudivax vaccine or Meruvax II vaccine. Adverse reactions occurred between 10 and 20 days after vaccination in 30% of the volunteers. After 28-35 days, vaccinees developed antibodies against rubella virus. The titer of rubella antibody reached it's peak from the 40th day through the 100th day. One year after vaccination, the geometric mean titer (GMT) of rubella virus antibody still remained over 1 : 64 (HAI) and 1 : 38.2 (FIA), and SPIA IgG RI mean was 2.80. Two years later, the antibody titers were 1 : 52 by HAI and 1 : 32.1 by FIA, and SPIA IgG RI mean was 2.75. After 5 years, the antibody titers were 1 : 48.6 (HAI) and 1 : 28.2 (FIA), and SPIA IgG RI mean was 2.74. After 10 years, the anti-rubella virus antibody titers were 1 : 38.9 (HAI) and 1 : 25.1 (FIA), and SPIA IgG RI mean was 2.42. LA antibody still remained seropositive. In conclusion, the rubella vaccine RA 27/3 is safe and efficient, and it is applicable for the control of the rubella in Taiwan.

Studies on cryopreservation of Toxoplasma gondii and its antigenicity in mice.

Two strains (RH and GC, the latter of which is a Taiwan isolate of porcine origin) of Toxoplasma gondii were kept at -20 degrees C, -60 degrees C, and in liquid nitrogen (-196 degrees C) to follow the time course change in viability and virulence of the parasites by direct count and animal inoculation methods. Changes in antibody titers in some of the mice inoculated with the thawed organisms were assayed by the indirect immunofluorescent antibody test. Viability and virulence of T. gondii were best preserved by storage in liquid nitrogen. Tachyzoites kept in liquid nitrogen for eight years still can lead to the death of the injected mice in 2-3 weeks. Virulence of the tachyzoites could be maintained for eight weeks at most at -20 degrees C and -60 degrees C. Dimethylsulfoxide (DMSO) seemed to be a better cryoprotectant for T. gondii than glycerol, but the DMSO-preserved organisms resulted in fewer tachyzoite-containing peritoneal exudates in inoculated mice than the glycerol-preserved organisms. The local isolate (GC strain) tachyzoites tolerated cryopreservation less well than the RH strain parasites. Low antibody titers (at most 1:64) were produced in mice that survived more than 16 days after inoculation with thawed tachyzoites.

Seroepidemiology of rubella virus infection among female residents on the offshore islets of Taiwan.

Although rubella vaccination was introduced in Taiwan in 1986 several outbreaks have occurred since then. In order to examine the epidemiological characteristics of rubella virus infection on the offshore islets of Taiwan, the Pescadore (Penghu) Islets and Orchid (Lan-Yu) Islet, the female residents of the islets aged 2-83 years were chosen as the study population. A community-based survey was carried out in three townships randomly selected through stratified sampling. Serum specimens of 677 healthy girls and women randomly sampled from the study areas were screened for the rubella antibody by a latex agglutination test and confirmed by a solid-phase immunoassay. A total of 415 subjects were antibody-positive giving a prevalence of 61.3%. The mean +/- standard deviation of rubella IgG index was 2.84 +/- 0.32. The seropositive rate increased with age in all three townships. The age pattern indicated that the regular ten-year rubella epidemic cycle ceased after 1978. A higher prevalence was observed in Orchid Islet than in the Pescadores. The overall seronegative rate was 48.7% (191/392) for females less than 20 years of age and 32.0% (48/150) for reproductive women between the ages of 20 and 35 years. With such a high proportion susceptible among females of child-bearing ages on the offshore islets of Taiwan, a mass rubella vaccination programme should be enforced in order to prevent possible outbreaks of congenital rubella syndrome in the future.

Current seroepidemiology of rubella virus infection among female residents in Taiwan.

To examine the epidemiological characteristics of rubella virus infection on Taiwan Island and in Orchid and Pescadore islets, a community-based survey was carried out in 19 townships and metropolitan precincts randomly selected through stratified sampling. Serum specimens of 4,770 healthy girls and women randomly sampled from study areas were screened for the rubella antibody by passive latex agglutination testing and confirmed by enzyme-linked immunosorbent assay. A total of 2,934 subjects were antibody positive, giving a prevalence of 61.5%. The mean +/- standard deviation of rubella IgG index was 2.51 +/- 0.37. The seropositive rate increased with age in all residential areas and ethnic groups. The age pattern indicated that the regular 10-year cycle of rubella epidemic was no longer existent after 1978. A higher prevalence was observed in the eastern island and Orchid Islets compared with other areas. The highest seropositive rate was found in Orchid Islets. The overall seronegative rate was 62.9% for females < 20 years of age and 36.9% for women between the ages of 20 and 29 years. With such a high susceptible density among girls and women of child-bearing ages as well as the endemicity of rubella virus infection in Taiwan, mass vaccination against rubella should be enforced in order to prevent possible future outbreaks of the congenital rubella syndrome.

[Application of staphylococcal protein A for immunodiagnosis of early toxoplasma infection].

RH strain Toxoplasma gondii was used to inoculate mice and rats. Sera collected at intervals were assayed by the indirect fluorescent antibody test (IFAT) and the latex agglutination test (LAT) to monitor the time-course change in titers of anti-toxoplasma IgM and IgG antibodies. In addition, the above sera and some anti-toxoplasma seropositive human sera (with IFAT antibody titers greater than or equal to 1:16) were adsorbed with staphylococcal protein A (SpA) and assayed for changes in IgM and IgG antibody titers so as to evaluate the usefulness of SpA adsorption in detecting anti-toxoplasma IgM which shows up early in toxoplasma infections. Samples assayed included 262 sera from mice, 65 sera from 5 rats and 85 human sera. The results revealed that parasite specific IgM-IFAT antibodies were detectable in 40% of the sera from mice 3 days after infection. After SpA adsorption, however, the IgM-IFAT antibody could be detected in a few specimens as early as 2 days post infection. IgG-IFAT and LAT antibodies first appeared in the sera on the 5th day of infection. In mice inoculated with freeze-killed tachyzoites (immunized mice), IgG-IFAT and LAT antibodies remained high from 16-35 days after inoculation, whereas IgM-IFAT antibodies were undetectable. Even after SpA treatment, only about half of the 16-day samples showed IgM antibody titers and the other specimens still remained negative. In general, IgM antibody titers increased 2-6 fold after SpA adsorption while IgG antibodies were almost completely removed after the treatment with a residual IgG-IFAT titer of less than or equal to 1:4.(ABSTRACT TRUNCATED AT 250 WORDS)