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Trypanosoma lewisi (Kinetoplastea: Trypanosomatida: Trypanosomatidae) with a cosmopolitan distribution is the type species of the subgenus Herpetosoma, which includes ca. 50 nominal species isolated mainly from rodents. Since members of Herpetosoma in different host species have an almost identical morphology of bloodstream forms, these trypanosomes are referred to as 'T. lewisi-like', and the molecular genetic characterization of each species is necessary to verify their taxonomy. In the present study, we collected blood samples from 89 murid rodents of 15 species and 11 soricids of four species in Indonesia, Philippines, Vietnam, Taiwan, and mainland China for the detection of hemoprotozoan infection. T. lewisi and T. lewisi-like trypanosomes were found in the blood smears of 10 murid animals, which included Bandicota indica (two rats), Rattus argentiventer (one rat), and Rattus tiomanicus (two rats) in Indonesia; Rattus rattus (one rat) in the Philippines; and Niviventer confucianus (four rats) in mainland China. Furthermore, large- or medium-sized non-T. lewisi-like trypanosomes were detected in two soricids, Crocidura dracula in Vietnam and Anourosorex yamashinai in Taiwan, respectively. Molecular genetic characterization of the small subunit (SSU) ribosomal RNA gene (rDNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene indicated that the trypanosomes from all the murid hosts had identical SSU rDNA or gGAPDH gene nucleotide sequences except for those in N. confucianus in mainland China. These N. confucianus-infecting trypanosomes also showed several unique morphological features such as smaller bodies, anteriorly positioned nuclei, and larger rod-shaped kinetoplasts when compared with T. lewisi trypomastigotes. Trypanosoma (Herpetosoma) niviventerae n. sp. is erected for this new species. Similarly, based on morphological and molecular genetic characterization, Trypanosoma sapaensis n. sp. and Trypanosoma anourosoricis n. sp. are proposed for the trypanosomes in C. dracula in Vietnam and A. yamashinai in Taiwan, respectively. More effort directed toward the morphological and molecular genetic characterization of the trypanosomes of rodents and soricids is required to fully understand the real biodiversity of their hemoflagellates.

Most foreign laborers in Taiwan come from Southeast Asia, where public health is not as well funded as in Taiwan, and parasitic infections are still common. Therefore, we recruited foreign laborers to undergo examination for parasitic infection to determine the infection conditions and follow-up conditions in foreign laborers whose stools were found to be abnormal. A total of 7,360 foreign laborers were enrolled for stool examination in our hospital, and the merthiolate iodine formaldehyde method was used to diagnose intestinal parasite infection. In total, 331 (4.5%) foreign laborers were found to be infected, and Blastocystis hominis was identified as the most prevalent intestinal parasite (2.54%), followed by Trichuris trichiura (0.54%) and hookworm (0.53%). Parasite infection rates among laborers of different nationalities were also significantly different (p < 0.001). Forty-two intestinal-parasite-infected foreign laborers received anti-parasitic therapy in our hospital, and treatment was successful. Among the 154 intestinal-parasite-infected foreign laborers who did not receive treatment in our hospital but were later re-examined, 132 were parasite-free. B. hominis has been the most prevalent intestinal parasite infecting foreign laborers in Taiwan ever since it was added to the list of infections to be screened for stool examination by the Taiwan Centers for Disease Control in 2002. It is important to closely monitor, control and treat parasite-infected foreign laborers to minimize the danger to public health.

To quantitate cerebrospinal fluid (CSF) concentrations of matrix metalloproteinase 9 (MMP-9) in adult patients with Klebsiella pneumoniae meningitis and to correlate levels of MMP-9 with parameters of intrathecal inflammation and analyze the kinetic changes of MMP-9. In a prospective cohort study, levels of MMP-9 and tissue inhibitor of matrix metalloproteinase (TIMP-1) concentrations were measured in the CSF of six adult patients with meningitis and 11 controls. MMP-9 and TIMP-1 were detected in all of the six patients at presentation and follow up lumbar puncture. CSF levels of MMP-9 (6.71+/-7.29 ng/ml) and TIMP-1(454.3+/-242.9 ng/ml) were higher in patients than in the control group (0.07+/-0.11 ng/ml and 27.14+/-39.34 ng/ml, respectively). Levels of MMP-9 correlated with CSF concentrations of protein, cell count and lactate. Repeated lumbar punctures showed that levels of MMP-9 decrease during clinical recovery, although the levels of MMP-9 in the CSF are variable because of the small number of cases. The relative change in gelatin zymography is comparable to the changes of MMP-9 levels found in ELISA. MMP-9 levels in CSF may be a useful tool in follow-up in patients with K. pneumoniae meningitis.

Vascular endothelial growth factor (VEGF) is a potent vascular permeability factor and a mediator of brain edema. To assess the role of vascular endothelial growth factor in eosinophilic meningitis, vascular endothelial growth factor was measured in the cerebrospinal fluid (CSF) and blood of 9 patients with eosinophilic meningitis in a cohort study. VEGFCSF was detected in 8 (90%) of 9 eosinophilic meningitis patients (range, 45-2190 pg/mL) at presentation. The mean VEGFCSF at presentation, 1 week, and 2 weeks after admission was 568 pg/mL, 751 pg/mL, and 1031 pg/mL, respectively. There was an association between VEGFCSF, CSF protein, white cell count, and eosinophil counts. The VEGFSERUM fluctuated during the 6-month follow-up period. These results indicate that vascular endothelial growth factor may be associated with blood-brain barrier disruption in patients with eosinophilic meningitis.

The most common cause of eosinophilic meningitis is the rat lungworm Angiostrongylus cantonensis a parasite that is endemic in the southeast Asian and Pacific regions. Outbreaks of eosinophilic meningitis associated with drinking raw vegetable juice are rarely reported, even in regions of endemic infection. We performed a cohort study among Taiwanese with eosinophilic meningitis who drank raw vegetable juice within three months of the onset of the outbreak. Clinical manifestations, laboratory examinations, and outcomes were prospectively followed. Five native Taiwanese met the case definition of eosinophilic meningitis. Specific antibodies to A. cantonensis were detected in the serum of five of the patients and in the cerebrospinal fluid (CSF) of four of the patients. Central nervous system manifestations included headache (n = 5 [100%]), Brudzinski's sign/stiff neck (n = 5 [100%]), hyperesthesia/paresthesias (n = 5 [100%]), and cranial nerve palsy (n = 1 [20%]). Laboratory findings included peripheral (n = 5 [100%]) and CSF eosinophilia (n = 4 [80%]), transient increases in the white blood cell count (n = 1 [20%]), and in serum levels of creatine kinase (n = 1 [20%]). Meningeal enhancement, as well as high signal intensity, at the subcortical white matter on T2 weighted and fluid attenuated inversion recovery images were observed on magnetic resonance imaging in four patients. There were three episodes of relapse during treatment and all resolved with after a lumbar puncture and/or administration of steroids. At the 12-month follow up, all five patients had recovered without neurologic sequelae. Risk factors identification showed that consumption of raw vegetable juice was associated with illness (Pearson correlation test r = 0.867, P = 0.01). There was association between the presence of raw vegetable juice and CSF eosinophilia (Spearman's correlation test r = 0.816, P = 0.004).

Hepatocyte growth factor (HGF) is a member of the angiogenic growth factor family, which exerts a variety of effects on epithelial, endothelial, and neuronal cells by binding to the c-MET receptor tyrosine kinase. It was reported that HGF attenuates cerebral ischemia-induced increase in permeability of the blood-brain barrier (BBB) and decreases in expression of tight junction proteins in cerebral vessels of rats. Studies on the localization of the c-Met/HGF receptor in the rat brain and the interaction with HGF after brain injuries show that HGF plays an important role as a neurotrophic factor in the brain. To assess the role of HGF in patients with eosinophilic meningitis, a retrospective, cohort study was conducted to measure the dynamic changes of HGF in the cerebrospinal fluid (CSF) and blood of nine patients with eosinophilic meningitis. The mean HGF(CSF) at presentation, 1 week, 2 weeks, and 3 weeks after admission was 539 pg/mL, 540 pg/mL, 376 pg/mL, and 279 pg/mL, respectively. The mean level of HGF(CSF) at presentation (539 +/- 242 pg/mL) and 1 week after admission (540 +/- 213 pg/mL) was significantly higher than in controls (162 +/- 207 pg/mL)(P = 0.02 and P = 0.01, respectively). The CSF/blood ratio of HGF at presentation (0.61) was higher when compared with physiologic situations in uninfected individuals (0.51). The levels of HGF in CSF were not correlated with the amount of CSF cells or proteins. All patients recovered without neurologic sequelae. These results indicate that high concentrations of HGF in the CSF occur in eosinophilic meningitis, and may have a role in protecting against endothelial injury and reducing BBB dysfunction.

Background Enteroviruses can cause outbreaks of hand-foot-and-mouth disease (characterized by vesicular lesions on the hands, feet, and oral mucosa) or herpangina, usually without life-threatening manifestations. In 1998 an epidemic of enterovirus 71 infection caused hand-foot-and-mouth disease and herpangina in thousands of people in Taiwan, some of whom died. Methods We assessed the epidemiologic aspects of this outbreak. Cases of hand-foot-and-mouth disease or herpangina in ambulatory patients were reported to the Taiwan Department of Health by a mean of 818 sentinel physicians. Severe cases in hospitalized patients were reported by 40 medical centers and regional hospitals. Viruses were isolated by 10 hospital laboratories and the department of health. Results The sentinel physicians reported 129,106 cases of hand-foot-and-mouth disease or herpangina in two waves of the epidemic, which probably represents less than 10 percent of the estimated total number of cases. There were 405 patients with severe ...

Although there have been some advances in the cryopreservation of Angiostrongylus cantonensis, the degrees of viability and infectivity of the cryopreserved developmental stages have not been high. A two-step freezing protocol using a programmable freezer was determined to be effective in improving the infectivity of the cryopreserved third-stage larvae of this parasite. After washing steps and suspension in 10% (v/v) dimethylsulfoxide and equilibrium at room temperature the larvae were placed into the freezer. The temperature was lowered first at 0.8 degrees C/min from room temperature to -40 degrees C and then at 10 degrees C/min to -70 degrees C. The samples were plunged into liquid nitrogen. After storage in liquid nitrogen for 7-15 days the larvae were thawed rapidly in 37 degrees C water and 27.6% were found to show vigorous "S-shape" movement without significant changes in appearance. These larvae (50/rodent) could develop to the fifth stage in mice (42.6%) and establish patent infection in rats (40.4%). Moreover, there was no significant difference in the recovery rates of cryopreserved worms and their unfrozen counterparts. These findings indicate that steady precooling conditions may decrease damage with regard to the infectivity of cryptopreserved third-stage larvae of A. cantonensis.

The formation of an aortic aneurysm caused by infection with Mycobacterium tuberculosis is rare. In a recent review of the English literature from 1945 to 1999 only 41 cases of tuberculous mycotic aneurysm of the aorta were identified. In this report we present our experience with one such patient and a brief review of the English language literature. An 80-year-old man was admitted to our hospital because of a one-week history of recurrent upper gastrointestinal bleeding. During this period upper gastrointestinal panendoscopy had failed to show active bleeding. Only a 2-cm linear ulcer with white base over the high body of the stomach was detected. He was given blood transfusions and a proton pump inhibitor. Eight years before admission he had had pneumonia of the right middle lobe. Bronchoscopic biopsy had revealed chronic granulomatous inflammation. Sputum mycobacterial culture was negative and he was treated with intravenous penicillin and erythromycin. Four years before admission he had experienced fever abdominal pain and jaundice. An abdominal computerized tomography scan done at that time was negative for an abdominal aneurysm. (excerpt)

When C57BL/6 mice were infected with Angiostrongylus cantonensis, the percentage of T helper (CD4+) cells and T supressor (CD8+) cells in peripheral blood increased weekly until the third and seventh week respectively, and then gradually decreased. C57BL/6 mice were depleted of CD4+ and CD8+ T cells by in vivo injection of anti-CD4 and anti-CD8 monoclonal antibodies, respectively, and then infected with A. cantonensis. There were significantly more and less worms recovered in the mice depleted of CD4+ and CD8+ T cells respectively than in undepleted mice. Discrete subpopulations of T cells from mice exposed to A. cantonensis for 3 weeks or 7 weeks were adoptively transferred to syngeneic recipients which were then given a challenge infection. Protection was mediated by a CD4+ T cell population present in mice after 3 weeks of infection but was not demonstrable with cells taken 7 weeks after infection. When CD4+ T cells obtained from 3-week infected mice were mixed with 5% CD8+ T cells obtained from mice infected for 7 weeks, no significant transfer of resistance was observed. Thus, immune responses to A. cantonensis in mice were regulated by discrete subpopulations of T lymphocytes.

This study was designed to determine the effects of age and the role of spleen in rats with heavy Angiostrongylus cantonensis infection. Young rats (8 weeks) infected with 100 larvae were found to have significantly higher worm recovery rate (75.0 ± 6.6%) than the adult (6 months) (55.7 ± 1.5%) and the aging ones (13 months) (57.6 ± 4.0%). Moreover, the recovery rate in adult rats with 400 larvae (33.6 ± 10.67%) was significantly lower than those with 100 larvae (55.7 ± 1.53%) or 200 larvae (53.3 ± 5.4%). The splenectomized young rats with 100 larvae had a significantly higher recovery rate (84.3 ± 2.5%) than the intact (75.0 ± 6.6%) or sham splenectomized ones (74.4 ± 3.8%). Although titers of antibody against A. cantonensis increased with time, those against young adults were significantly higher before week 4 whereas those against adult worms become significantly higher since week 4. Titers in the splenectomized rats were also found to be significantly lower than those in the intact ones. These finding indicate that young rats are more susceptible to A. cantonensis. Crowding effect may occur in rats with heavy infections. The effects of splenectomy on the host are independent of the intensity of infection.

Angiostrongylus cantonensis is a parasite endemic in the Southeast Asian and Pacific regions. Humans are incidentally infected either by eating uncooked intermediate hosts or by consuming vegetables containing the living third-stage larvae. Reports on brain magnetic resonance imaging (MRI) findings and how they correlate with clinical features are limited in the literature. In this retrospective study, we investigated the brain MR features of eosinophilic meningitis caused by human infection with A. cantonensis. A detailed clinical study of 26 of these patients was conducted. The brain MRI findings were nonspecific, ranging from normal (n=1), leptomeningeal enhancement (n=21), hyperintense signal lesions (n=11) on T2-weighted MRI and nodular enhancing lesions in gadolinium-enhanced T1W1 (n=1). There was an association between the presence of brain MRI high signal intensities with peripheral eosinophilia (p=0.02), cerebrospinal fluid (CSF), eosinophil count ≥10%, and the presence of CSF antibodies to A. cantonensis (p=0.01). The patients with leptomeningeal enhancement in brain MRI tended to be younger and predominantly men (p=0.03). The time from onset of symptom to spinal tapping or brain MRI studies did not have an effect on the presence of brain MRI abnormalities. The brain MRI findings did not add any additional importance to the clinical evaluation of patients with eosinophilic meningitis in this series. Further studies are required to clarify the role of brain MRI in eosinophilic meningitis.

SUMMARYPinworm infection remains prevalent in children in many parts of the world. This study was designed to determine the prevalence of this infection in schoolchildren in Taiwan after the termination of the 15-year population-based control project in 2001. Our results showed that 2·4% of 118 190 children in 385 primary schools were found to have enterobiasis by two-consecutive-day adhesive cellophane perianal swabs. The prevalences were significantly different in the 25 counties/cities surveyed (0·6–6·6%). A significantly higher prevalence was found in boys (2·6%) than in girls (2·2%) and the prevalence decreased by grade from 3·8% in grade 1 to 1·0% in grade 6. In the primary schools, 9·1% had positive rates ⩾10%. In addition, pinworm infection was found to be significantly associated with the socioeconomic status, personal hygiene and sanitary conditions of the children. The results indicate that the overall prevalence of enterobiasis remains at a low level after the control programme was transferred to the local governments.

Stomach intubation is the most common method used in the experimental infection of animals with Angiostrongylus cantonensis. In order to compare the effectiveness of other possible transmission methods, groups of BALB/c mice were given infective third-stage larvae of A. cantonensis by different routes including intraperitoneal or subcutaneous injections, and penetration of anal mucosa, vaginal mucosa, conjunctival mucosa, lacerated skin, unabraded skin, foot pad and tail skin, while stomach intubation was used as control. Recovery of fifth-stage larvae was higher in mice inoculated with third-stage larvae subcutaneously. Successful infections were established through all experimental transmission routes except tail skin penetration. This study suggests that oral infection may not be the only route for the transmission of human angiostrongyliasis, and subcutaneous infection may be a better method for experimental infection.

Three IgG1 and one IgG2a monoclonal antibodies were obtained by fusion of NS-1 cells with spleen cells of BALB/C mice immunized with young-adult worm antigen of A. cantonensis. These 4 monoclonal antibodies were specific to A. cantonensis without cross-reactivity to any antigens of Toxocara canis, Ascaris suum, Clonorchis sinensis, Dirofilaria immitis, Paragonimus westermani, Gnathostoma spinigerum, Strongyloides stercoralis and Anisakis spp. detected by ELISA. The affinity constants of monoclonal antibodies specific to young-adult worms antigen of A. cantonensis were in the range of 10(7) M-1 to 10(9) M-1. The immunoblots showed that the 4 monoclonal antibodies recognized epitope on molecular weight of 204 kiloDaltons. They will be utilized to purify their corresponding antigen by an immunoaffinity column for the specific immunodiagnosis.

Invasive amoebiasis is rarely seen in human immunodeficiency virus (HIV)-infected individuals, even in endemic areas. By contrast, cytomegalovirus (CMV) disease is recognized as a major clinical problem in acquired immunodeficiency syndrome patients. A 34-year-old HIV-infected man with amoeba colitis, disseminated Mycobacterium avian complex and CMV infection with cecum perforation, presented with the initial symptoms of fever, shortness of breath and painful sensation when swallowing. He was treated with fluconazole, trimethoprim-sulfamethoxazole and hydrocortisone under the impression of esophageal candidiasis and Pneumocystis jiroveci pneumonia. However, diarrhea and abdominal pain developed on day 6 of hospitalization. Invasive amoebiasis and CMV colitis was diagnosed after examination of colon pathological specimens. Emergent laparotomy was performed. Right hemicolectomy with double barrel ileostomy and colostomy was done due to perforation of the cecum. Iodoquinol was given, followed by metronidazole 14 days afterwards. He underwent closure of double barrel ileostomy and colostomy 5 months later. This case illustrates the diagnostic challenge of caring for acquired immunodeficiency syndrome persons with multiple illnesses and medication use. CMV infection, amoebic colitis and possibly corticosteroid may have played a role in colon perforation in our patient.

In spring, windblown dust storms originating in the deserts of Mongolia and China make their way to Taipei City. These occurrences are known as Asian dust storm events. The objective of this study was to assess the possible effects of Asian dust storms on the mortality of residents in Taipei, Taiwan, during the period from 1995 to 2000. We identified 39 dust storm episodes, which were classified as index days. Daily deaths on the index days were compared with deaths on the comparison days. We selected two comparison days for each index day, 7 days before the index day and 7 days after the index day. The strongest estimated effects of dust storms were increases of 7.66% in risk for respiratory disease 1 day after the event, 4.92% for total deaths 2 days following the dust storms and 2.59% for circulatory diseases 2 days following the dust storms. However, none of these effects were statistically significant. This study found greater specificity for associations with respiratory deaths, and this increases the likelihood that the association between dust events and daily mortality represents a causal relationship.

Toxoplasmosis is the most common opportunistic infection of the central nervous system in patients with AIDS. The standard treatment for toxoplasmic encephalitis is pyrimethamine and sulfadiazine. There have been few reports of concurrent Toxoplasma brain abscess and cavitary Pneumocystis carinii pneumonia (PCP) in Taiwan. We report the case of a 26-year-old homosexual man with coexisting infection with Toxoplasma gondii and P. carinii who was successfully treated for brain abscess with clindamycin and sulfadiazine. The cavitary lung lesions, initially diagnosed as pulmonary tuberculosis, were proved to be PCP by lung biopsy. HIV infection and syphilis had been diagnosed 1 year before admission. He presented with general weakness, ataxia, nausea, blurred vision and fever for 2 weeks. Magnetic resonance imaging of the brain revealed multiple ring-enhanced lesions over the cerebrum and cerebellum. Chest roentgenography showed a 3-cm lesion with cavitation over the right upper lung field. Diagnostic computerized tomography-guided lung biopsy revealed P. carinii cysts. Clindamycin, sulfadiazine and trimethoprim (TMP)-sulfamethoxazole (20 mg/kg/day TMP) were given with good response. His CD4 count rose from 40 to 280/microL 4 months later. All antibiotics were discontinued after 4.5 months due to the development of a skin rash. He was well at follow-up 1 year later. This case suggests that the combination of clindamycin and sulfadiazine is an effective treatment for Toxoplasma brain abscess and highlights the importance of diagnostic lung biopsy for cavitary lung lesions, particularly in a region endemic for tuberculosis.

Snails and freshwater fish were examined from four ponds in the Meinung township in which Clonorchis sinensis was known to be endemic 18 years ago. No metacercariae were found in 478 Tilapia nilotica, whereas of 451 Ctenopharyngodon idellus examined, 16.2%, 3.3% and 0.9% were found to be infected with Haplorchis pumilio, H. taichui and Clonorchis sinensis, respectively. In addition, there were some unidentified metacercariae in 12.0% of Ctenopharyngodon idellus examined. Overall, no positive correlation between infection rates and sizes of infected fish was shown. Six species of snails were collected in this survey and two frequently-occurring snails, Melanoides tuberculata and Thiara granifera were commonly infected with H. pumilio. Reasons for the prevalence of Haplorchis species and the absence of Clonorchis sinensis in fish and snail hosts in a previously reported endemic area for human clonorchiasis are discussed.

The diagnosis and management of strongyloidiasis present a continuous challenge in developing countries including Taiwan. In this study, the clinical characteristics and microbiological findings of 27 patients with Strongyloides stercoralis infection were retrospectively analyzed. Intestinal infection was identified in 17 patients and hyperinfection syndrome or disseminated disease in 10 (including 2 autopsy cases). The most frequent clinical findings were diarrhea (74%), fever (70%), abdominal pain (59%), cough (37%), dyspnea (33%), and constipation (26%). The common initial laboratory abnormalities were leukocytosis (81%), anemia (67%), liver function impairment (52%), and eosinophilia (44%). Most of the 27 patients had comorbid conditions, including malnutrition in 20 (74%), corticosteroid dependence in 15 (55%), chronic obstructive pulmonary disease in 9 (33%), chronic liver disease or cirrhosis in 8 (30%), and peptic ulcer disease in 7 (26%). There was no difference in the time interval from symptom onset to diagnosis between the intestinal infection group and the hyperinfection/disseminated group (22 +/- 15 vs 17 +/- 9 days). Larvae of S. stercoralis were identified in the stool of 24 patients, in the sputum smear of 5, in the gastric biopsy of one, and on histology of autopsy specimens in 2. Twenty-six patients received antiparasitic drug therapy of variable duration (mebendazole in 24, albendazole in 2, combined therapy in one). The overall cure rate was 52% (14/27). Relapse occurred in 4 patients. The overall mortality was 26% (7/27). There was a high mortality (up to 50%) in the hyperinfection/disseminated disease group. In conclusion, diagnosis of strongyloidiasis is often delayed and overlooked because of nonspecific symptoms. Physicians in endemic regions should include strongyloidiasis in the differential diagnosis when patients present with gastrointestinal and/or pulmonary symptoms with peripheral eosinophilia.

Cobalt-60 gamma irradiation was used to kill the larvae of Angiostrongylus cantonensis in four groups of snails that were irradiated at a rate of 15.4 Gy/min for 16.23 min (0.25 kGy), 32.47 min (0.50 kGy), 48.70 min (0.75 kGy), and 64.94 min (1.00 kGy), respectively. Third-stage (infected stage) larvae were isolated from these snails and 50 were administered to each experimental animal via an esophageal tube. At a dosage of 0.25 kGy, the mean +/- SD number of worms recovered from 30 rats and 30 mice was 15.6 +/- 6.5 and 11.3 +/- 6.2, respectively. These were significantly different from the number of worms recovered from the nonirradiated (control) groups, which were 28.9 +/- 9.6 (P < 0.05) and 16.6 +/- 10.3 (P < 0.05) for rats and mice respectively. Worms and cellular infiltrations in lung tissue of rats were histopathologically identified in the 0.25-kGy-irradiated group as well as in the control group. Worms and eosinophilic meningitis were also noted in the brain tissue of mice in control groups. No worms or pathologic findings were observed in the heart, lung, or brain tissue of rats or mice infected with larvae irradiated at or exceeding 0.50 kGy. It is therefore concluded that a dosage of 0.50 kGy is sufficient to prevent successful infection in mice and rats.

The vector competence in Ae. aegypti (L.) and Ae. albopictus (Skuse) from southern Taiwan to the dengue 1 virus was studied to elucidate the distribution of dengue infection during the 1987-1988 outbreak. The brain of Ae. aegypti was infected as early as 3 d after intrathoracic inoculation. The esophagus and the proboscis (tissues within the labium) were infected 5 d after inoculation. The salivary gland was highly susceptible to the virus, but no specific infection site was found. Gangli, muscles, and diverticula within the thorax were not infected. In the abdominal area, the ventral diverticula, Malpighian tubules, ganglia, and the dorsal vessel were not infected. However, the entire gut was susceptible to dengue 1 virus, although it was not infected simultaneously. Only a certain type of midgut epithelial cells was infected by the virus. The ovarioles, oviducts, and accessory glands frequently were infected. However, the spermathecae were not infected, perhaps because of the chitin-rich outer layer. Infections of the testes, vas deferens, seminal vesicles, and accessory glands of males also were detected in this study. The tissues of the proboscis were never infected in Ae. albopictus but frequently were infected in Ae. aegypti, indicating that the virus may escape the salivary gland barrier more efficiently in Ae. aegypti than in Ae. albopictus. When these mosquitoes were fed on hanging drops, the salivary gland infection and transmission rates of Ae. aegypti were always higher than those of Ae. albopictus. On Taiwan, Ae. aegypti appears to be a more competent vector in the transmission of the dengue 1 virus than Ae. albopictus.

Attempts have been made to increase the survival rate of third-stage larvae of Parastrongylus cantonensis during cryopreservation. Parasites were obtained from experimentally infected snails, Biomphalaria glabrata. The maximum non-toxic concentrations of cryoprotectants dimethyl sulphoxide (DMSO) and glycerol were determined as 10% v/v in NCTC 109 medium. Different pre-cooling times and serum additives were assayed to determine their effects on the viability of larvae. Larvae pre-cooled at –20°C for 15–20 minutes before transfer to –70°C had the optimum survival rate. The presence of serum was essential for further cooling to –196°C. There were no differences between native and heat-inactivated sera on the larval viability. The survival of larvae recovered after storage at –196°C was higher in sera collected from the rat, man, or fetal calf than in sera collected from the mouse, dog, or horse. Viability assessed by mouse-infections showed that thawed larvae retained infectivity for susceptible hosts, but it was significantly lower than that of unfrozen control worms.

Specimens of serum and bile from patients were assayed by an enzyme-linked immunosorbent assay to reveal antibodies specific to antigens from adult Clonorchis sinensis. Antibodies of the IgG isotype showed the greatest elevation during infection (Student's t-test, P < 0.001), whereas serum IgA and IgE and secretory IgA in bile were moderately elevated (P < 0.05). Major differences in the distribution of antibodies among the IgG subclasses were observed between patients who were and those who were not infected. IgG4 antibody levels were elevated in the serum and bile of infected patients, and there were significant correlations between the levels of IgG and IgG4 antibodies and the intensity of infection.

Up to now, there has been no studies about the immune status of PCB transplacental Yu-Cheng babies. In an earlier study, Yu-Cheng babies were reported to have a high infant mortality rate. It was reported that these babies would easily catch cold, experience diarrhea and abdominal pains. Recently, it was found that the bronchitis rate of Yu-Cheng babies is higher than in control babies. Because of high risk of infection, it is presumed that these babies might suffer immunosuppression to a certain extent. According to these findings, investigations into the immune functions of PCB transplacental Yu-Cheng babies are needed.

In order to compare the prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) infection among five ethnic groups in Pingtung County of southern Taiwan, a total of 240 serum samples were collected from September to October, 1985, from the following five ethnic groups: Taiwanese, Hakka, Mainland Chinese, aboriginal Paiwanese, and aboriginal Rukaiese. Ages of subjects ranged from 5 to 69 years. All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA). Hepatitis B e antigen (HBeAg) and antibody to hepatitis D antigen (anti-HDV) were also tested for those with HBsAg-positive sera. Results showed that 44.1% of all sera examined were negative for HBsAG but positive for both anti-HBs and anti-HBc; additionally, 24.6% were negative for both HBsAg and anti-HBs but positive for anti-HBc. Only 134 serum samples showed negative results for HBV markers, indicating an HBV infection rate of 88.8%. The anti-HDV positive rate was estimated to be 2.7% among HBsAg-positive subjects. The HBsAg-positive rates among Rukaiese, Paiwanese, Hakka, Taiwanese, and Mainland Chinese were 25.8, 22.5, 16.7, 12.9, and 10.0%, respectively; while the prevalence rates of HBV infection among the above five groups were 94.2, 94.6, 85.4, 87.5, and 82.5%, respectively. Differences in the HBsAg-positive rate and HBV infection rate among these ethnic groups were statistically significant. We conclude that people living in Pingtung County are more frequently infected with HBV when compared with inhabitants in northern Taiwan.

Mice were infected with 50 third stage larvae of Angiostrongylus cantonensis and treated orally with albendazole (Zentel) in dosages of 5, 10, and 25 mg/kg/day begun 5, 10, or 15 days post-infection for 7, 14, or 21 consecutive days. The mice in each group were killed 3 days after cessation of treatment and the brains examined for parasites. Worms were recovered from the brains of all mice treated for 7 days, but recoveries from treated mice were significantly lower than from controls. Worm reduction was nearly 100% in mice treated for 14 days when treatment was initiated 5 and 10 days post-infection. Worms were found in the brain of mice treated for 14 days when treatment began at 15 and 20 days, but recovery rates were significantly lower than in controls. Similar results were obtained in animals treated for 21 days. Worm reduction rates were lower in animals given 5 mg/kg/day, but there was no significant difference in animals given higher dosages. Albendazole was effective in the treatment of A. cantonensis in mice when given within 15 days post-infection.

The genetic polymorphisms of orosomucoid, ORM1 and ORM2, were analyzed by isoelectric focusing on polyacrylamide gels and subsequent immunoprinting. Sera from 600 unrelated individuals in Taiwan and Japan were examined. Five new alleles, designated ORM1*7, ORM1*8, ORM1*4.2, ORM2*8 and ORM2*10, were observed together with common and rare alleles that have been found in the Japanese and the Filipinos. As compared with the Japanese, the Taiwanese have a higher frequency of ORM1*1, and a significantly lower frequency of ORM1*2.1.

A study of the epidemiologic characteristics of 125 cases of eosinophilic meningitis or meningoencephalitis, probably caused by Angiostrongylus cantonensis, which occurred in southern Taiwan in 1968 and 1969 revealed a close association of the disease with the rainy season. In contrast to findings in other geographic areas, most such cases in this study occurred among children. A higher attack rate was observed among aborigines than among descendants of mainland Chinese. Most patients had eaten the giant African snail, Achatina fulica, prior to their illness and this mollusc was commonly found infected with third-stage larvae of A. cantonensis. However, in almost all instances the snail was eaten after it had been thoroughly cooked and examination of cooked snail meat revealed only dead larvae. It it suspected that patients became infected by inadvertently ingesting A. cantonensis larvae liberated when the snails were prepared for consumption.

A total of 390 parenteral drug abusers (PDAs) at the Kaohsiung Municipal Narcotics Abstention Institute were examined for markers of hepatitis B virus (HBV), hepatitis D virus (HDV), and human immunodeficiency virus (HIV). All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA) and for antibody to HIV (anti-HIV) by enzyme-linked immunosorbent assay (ELISA). Hepatitis B e antigen (HBeAg) and antibody to HDV (anti-HDV) were also tested for HBsAg-positive serum samples. Although the HBsAg-positive rate (22.1%) among PDAs was similar to that of the general population in southern Taiwan, the HBV infection rate (99.2%) and the anti-HDV-positive rate (78.5%) among HBsAg-positive subjects were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). None of the PDAs studied were positive for anti-HIV. The levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) among PDAs were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). The more frequent the institutionalisation, the higher the infection rates with HBV and HDV and elevated levels of SGOT and SGPT. Horizontal transmission through parenteral drug abuse may be considered a possible reason for the significantly higher rates of HBV and HDV among parenteral drug abusers.

This paper is intended to present a study of transplacental Yu-Cheng babies in Taiwan. The focus of the study is to demonstrate how a contaminated food source can affect the growth and development of permanent teeth germ in children. A sporadic outbreak of a peculiar skin disease was reported in Japan in October of 1968. An epidemiological study revealed the outbreak of this disease was caused by contaminated Kanemi rice oil. This episode of rice oil poisoned with polychlorinated biphenyls (PCB) was the first reported outbreak of PCB poisoning in the world. A second episode occurred in central Taiwan eleven years after the Japanese episode. Registered data from the Taiwan Provincial Government Health Department reported 1,843 cases in 1980. Of this group, more than 800 women were child-bearing age and most of these women would or soon would be married and pregnant. The offsprings of these women were in danger, because it has been proven that PCB intoxication could affect the fetus. These babies, only contaminated through the placenta, are called PCB transplacental Yusho babies in Japan and PCB transplacental Yu-Cheng babies in Taiwan. Babies with PCB poisoning could have Fetal PCB syndrome (FPS) and may have retarded eruption ofmore » permanent teeth and other anomalies such as reduced numbers of teeth and abnormal shaped roots. The study of transplacental Yu-Cheng babies is an important public health issue for Taiwan. Although there may be other issues, this study focuses only on the growth and development of permanent teeth of those babies affected by PCB transplacental contamination.« less