Oxidative stress in mice infected with Angiostrongylus cantonensis coincides with enhanced glutathione-dependent enzymes activity

This study aimed to estimate reactive oxygen species (ROS) production, antioxidants activity, and biomarkers level of oxidative damage to protein and DNA in the cerebrospinal fluid (CSF) of C57BL/6 mice infected with Angiostrongylus cantonensis. The mean ROS concentration in the CSF of infected mice increased gradually, and the increase in ROS in CSF became statistical significance at days 12-30 post-infection compared to that before infection (P<0.001), and then ROS returned to normal level at day 45 after infection. In parallel with the increase in ROS in the CSF, infected mice showed similar of changes in reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST) as that in ROS in the CSF. GSH, GR, GPx, and GST in the CSF of infected mice were all significantly higher than they were before infection during days 12-30 post-infection. However, protein carbonyl content and 8-hydroxy-2'-deoxyguanosine, biomarkers of oxidative damage to protein and DNA, respectively, were also significantly higher in the CSF of infected mice during this period. These results suggest that oxidative stress occur in the cells of central nervous system of mice infected with A. cantonensis during days 12-30 after infection due to ROS overproduction in CSF despite the increase in antioxidants during this period.

Dynamic changes of hepatocyte growth factor in eosinophilic meningitis caused by Angiostrongylus cantonensis infection

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.

Dynamic changes of matrix metalloproteinase-9 in patients with Klebsiella pneumoniae meningitis

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.

Anticancer activity of isoobtusilactone A from Cinnamomum kotoense: involvement of apoptosis, cell-cycle dysregulation, mitochondria regulation, and reactive oxygen species

In this study, we investigate the anticancer effect of isoobtusilactone A (IOA), a constituent isolated from the leaves of Cinnamomum kotoense, on human non-small cell lung cancer (NSCLC) A549 cells. IOA was found to induce the arrest of G2-M phase, induce apoptosis, increase sub-G1, and inhibit the growth of these cells. Further investigation revealed that IOA's blockade of the cell cycle was associated with increased levels of p21/WAF1, p27 (kip1), and p53. In addition, IOA triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratios, resulting in a loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of PARP. We also found the generation of reactive oxygen species (ROS) to be a critical mediator in IOA-induced inhibition of A549 cell growth. In antioxidant and NO inhibitor studies, we found that by pretreating A549 cells with either N-acetylcystenine (NAC), catalase, mannitol, dexamethasone, trolox, or L-NAME we could significantly decrease IOA production of ROS. Moreover, using NAC to block ROS, we could significantly suppress IOA-induced antiproliferation, antimigration, and anti-invasion. Finally, we found that IOA inhibited the migration and invasion of A549 cell migration and invasion. Taken together, these results suggest that IOA has anticancer effects on A549 cells.

Association of matrix metalloproteinase-9 and tissue inhibitors of metalloproteinase-4 in cerebrospinal fluid with blood-brain barrier dysfunction in patients with eosinophilic meningitis caused by Angiostrongylus cantonensis

To evaluate possible blood-brain barrier (BBB) dysfunction caused by matrix metalloproteinase-9 (MMP-9) and its regulation by tissue inhibitors of metalloproteinase (TIMPs) in patients with eosinophilic meningitis caused by infection with Angiostrongylus cantonensis, 40 patients and 28 controls were included in this study. Concentrations of MMP-2, MMP-9, TIMP-1, and cerebrospinal fluid (CSF):serum albumin ratios (Q(Alb) values) were significantly increased in patients compared with controls. However, concentrations of TIMP-4 were significantly lower in patients. In contrast to MMP-2, proteolytic activity of MMP-9 detected by gelatin zymography was only observed in patients with eosinophilic meningitis. We detected higher levels of antibodies specific for A. cantonensis and higher Q(Alb) values and MMP-9 concentrations in CSF of patients with eosinophilic meningitis, Furthermore, the increase in the Q(Alb) value was significantly correlated with the increase in MMP-9 in patients. In parallel with CSF MMP-9, patients also showed an increase in CSF leukocyte counts. Gradual decreases in levels of Q(Alb), MMP-9, and TIMP-1 and increases in levels of TIMP-4 were observed in six patients during recovery from eosinophilic meningitis. These results suggest that the source of MMP-9 in CSF of patients with eosinophilic meningitis was probably associated with leukocytes migrating from peripheral blood to CSF. Activity of MMP-9 in CSF of patients could not be completely inhibited because of the decrease of TIMP-4, which may cause BBB dysfunction, as shown by higher Q(Alb) values in patients.

Vascular endothelial growth factor is associated with blood brain barrier dysfunction in eosinophilic meningitis caused by Angiostrongylus cantonensis infection

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.

Eosinophilic meningitis caused by Angiostrongylus cantonensis after ingestion of raw frogs

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis in humans after ingestion of raw or inadequately cooked intermediate hosts or food contaminated with infective third-stage larvae. Frogs are known to be a paratenic host of A. cantonensis, but have never been reported as the infectious source of human angiostrongyliasis in Taiwan. We report the first case of eosinophilic meningitis caused by A. cantonensis after ingestion of raw frogs (Rana plancyi).

Diphyllobothriasis latum: the first child case report in Taiwan

Diphyllobothriasis latum is an intestinal parasitosis caused by the ingestion of mostly raw fresh-water fish containing plerocercoids of Diphyllobothrium latum. We report an 8-year-old boy who came to our hospital with the complaint of a tapeworm hanging from the anus after defecation. The other symptom was mild abdominal cramping for a period of 1 year. The laboratory examination did not reveal anemia or vitamin B12 deficiency. Examination of gravid proglottids with rosette-like central uterus and typically operculated eggs of D. latum confirmed the diagnosis. The morphologic characters of proglottids and eggs size are compatible with D. latum. The patient had a history of eating uncooked fish for 1 year. Salmonids may be the infection source. He was treated with two doses of praziquantel and passed about 183 cm in length of all proglottids. There is a high prevalence of diphyllobothriasis latum in the northern temperate areas, but it is very rare in children. This patient is the first child case reported in Taiwan.

Blood-brain barrier dysfunction occurring in mice infected with Angiostrongylus cantonensis

Several indices were used to assess whether blood-brain barrier (BBB) damage occurs in neurological disorders. Dysfunction of the BBB was surmised to be involved in the pathological changes of eosinophilic meningitis caused by the infection of Angiostrongylus cantonensis. The mean concentration of protein and albumin in the cerebrospinal fluid (CSF) of infected mice gradually increased from days 0 to 18 after infection and then rapidly increased 21 days after infection. The concentrations of protein and albumin in the CSF of infected mice 15 days after infection were all significantly higher than those in uninfected mice (all P-values at least <0.05). Parallel with the increase in protein and albumin in the CSF, infected mice showed a gradual increase in their CSF/serum protein and albumin ratios. The increase became significant at days 21 and 18 after infection, respectively (P<0.01 and P<0.05, respectively). The higher the worm counts in the brain, the higher the CSF/serum albumin ratio was observed in infected mice at day 21 after infection (P<0.001). In addition, the ratios of the CSF/serum albumin were positively correlated with the worm counts in the brain (P<0.001). The total leukocyte and eosinophil counts were also positively correlated with ratios of CSF/serum albumin (P<0.01). The amount of Evans blue in the brain of mice 21 days after infection from peripheral blood via BBB became significantly increased than those in uninfected mice (P<0.001). Thus, the evidence of high concentrations of protein and albumin, high leukocyte counts in CSF, high ratio of CSF/serum protein and albumin, and high permeability of BBB show that dysfunction of the BBB occurred in mice infected with A. cantonensis.

Colon perforation with peritonitis in an acquired immunodeficiency syndrome patient due to cytomegalovirus and amoebic colitis

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.

Immunogenicity and anti-Burkholderia pseudomallei activity in Balb/c mice immunized with plasmid DNA encoding flagellin

Plasmid DNA encoding the flagella protein (flagellin) was used as a vaccination candidate for the evaluation of its immunogenicity and for protection against infection with Burkholderia pseudomallei. Firstly, flagellin encoding plasmid DNA was injected into Balb/c mice intramuscularly and this elicited both a humoral and a cellular immune response. Total IgG production and the clonal expansion of the spleen cells increased in response to flagellin. The IgG subclass response exhibited a dominance of IgG2a over IgG1 in the sera. In addition, IFN-gamma-secreting cells in the spleen were substantially increased. Furthermore, the anti-B. pseudomallei activity of the peritoneal exudate cells was evaluated by a Transwell tissue-culture plate system where the macrophage-activating related cytokines in upper chamber were allowed to cross the plate's membrane and stimulate the activation of peritoneal exudate cells in lower chamber. Our results indicated that the activated peritoneal exudate cells were able to restrict the growth of B. pseudomallei in vitro. Indeed, subsequent intravenous challenge of the vaccinated Balb/c mice with 10(5)CFU of B. pseudomallei resulted in the number of bacterial cells detected in liver and/or spleen being significantly reduced in the flagellin plasmid DNA vaccinated mice. At 7 days subsequent to infection of B. pseudomallei, 5/6 (83%) of flagellin plasmid DNA vaccinated mice had survived. We suggest that plasmid DNA-encoding flagellin might be useful as a potential immunization route for the future development of a vaccine against melioidosis in related animals.

Protease secreted by the infective larvae of angiostrongylus cantonensis and its role in the penetration of mouse intestine

The infective third-stage larvae of Angiostrongylus cantonensis secrete a proteolytic enzyme that is thought to be essential for both larval penetration into the intestinal wall of the host and full development. Protease activity in these larvae during culture in vitro was determined by zymography, pH optimum, and substrate and inhibitor specificity. Excretory-secretory (ES) products of the third-stage larvae showed protease activity as three bands with molecular masses of 66, 30, and 23 kD by gelatin zymography. The optimal pH value for this protease activity was 10.0. The protease was found to have collagenolytic as well as elastinolytic activity, but these activities were inhibited by serine protease or metalloprotease inhibitors. The importance of this protease in larval penetration of the intestinal wall and entering the blood stream was observed in vitro by cocultured third-stage larvae of A. cantonensis with specific protease inhibitors in the intestines of BALB/c mice. The penetration rates of larvae significantly decreased when serine protease or metalloprotease inhibitors were added to the intestines. These results showed that serine protease and metalloprotease in ES products of A. cantonensis third-stage larvae are associated with larval penetration of the intestinal walls of mice.

Relation of hepatolithiasis to helminthic infestation

BACKGROUND AND AIM

The relation of helminthic infestation to hepatolithiasis is a subject of dispute. This case-control study was undertaken to evaluate the prevalence of helminthiasis in hepatolithiasis patients and to compare the clinicopathological features of hepatolithiasis between patients with and without helminthiasis.

METHODS

The prevalence of ascariasis or clonorchiasis was evaluated using ELISA in 131 patients with hepatolithiasis who were treated at Show-Chwan Memorial Hospital and 121 subjects who constituted a control group. The patients' detailed histories and medical charts were reviewed.

RESULTS

The prevalence of positive immunodiagnosis of ascariasis and clonorchiasis was higher in patients with hepatolithiasis than in control subjects (33.6%, 44/131 vs 17.4%, 21/121, odds ratio [OR] = 2.41, 95% confidence interval [CI] = 1.28-4.56, P = 0.005; and 6.9%, 9/131 v 0.8%, 1/121, OR = 8.85, 95% CI = 1.12-188.69, P = 0.02). Patients with helminthiasis rarely had concurrent gallbladder stones (26%, 12/47 vs 55%, 46/84, OR = 0.28, 95% CI = 0.12-0.66, P = 0.002). Prior to the diagnosis of hepatolithiasis in adulthood, most of the patients with helminthiasis tended to have a history of recurrent abdominal pain in their childhood and an asymptomatic 'lucid interval' during their teenage years (70.2%, 33/47 vs 39.3%, 33/84, OR = 3.64, 95% CI = 1.59-8.42, P = 0.0005). However, the prevalence of intrahepatic duct stricture (38.3%, 18/47 vs 40.5%, 34/84, OR = 0.91, 95% CI = 0.41-2.02, P > 0.05), secondary biliary cirrhosis (6.4%, 3/47 vs 3.6%, 3/84, OR = 1.84, 95% CI = 0.28-12.03, P > 0.05), cholangiocarcinoma (2.1%, 1/47 vs 0%, 0/84, OR = approximately , P > 0.05), and stone recurrence (54.8%, 24/42 vs 50.0%, 38/76, OR = 1.33, 95% CI = 0.58-3.06, P > 0.05) did not significantly increase.

CONCLUSIONS

Helminthiasis is a possible risk factor for hepatolithiasis, although it is unlikely to increase the incidence of complications, including bile duct stricture, secondary biliary cirrhosis, and cholangiocarcinoma. Patients with helminthiasis tend to have a history of an asymptomatic 'lucid interval' between the periods of recurrent abdominal pain in their childhood and the diagnosis of hepatolithiasis in their adulthood.

Outbreak of eosinophilic meningitis associated with drinking raw vegetable juice in southern Taiwan

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).

The influence of zinc in mice on infection with Angiostrongylus cantonensis

BALB/cByJ mice were divided into zinc-deficient (ZD), high zinc-supplemented (ZH), adequately zinc-replete (ZA) and normal control groups by daily dietary control. The body weight in ZD and ZH mice became significantly less than that of normal control mice from 4 weeks (P < 0.002) until 7 weeks (P < 0.0001) after consecutive zinc control. The kinetics of change in body weight of ZD and ZH mice after infection with Angiostrongylus cantonensis were similar to that of uninfected groups mentioned above. The worms recovered at days 7, 14 and 21 after infection from ZD and ZH mice were significantly more in number than that in control mice (P < 0.01). However, the worms from day 21 after infection were shorter in size than those in control mice (P < 0.01). The production of interleukin (IL)-5 was significantly depressed in cultured spleen cells from uninfected and infected ZD and ZH mice, compared with that from respective control group (P < or = 0.02). Furthermore, significantly lower eosinophil counts were observed in the cerebral spinal fluid(CSF) of ZD and ZH mice 3 weeks after infection than in the CSF of control mice (P < 0.001). The levels of immunoglobulins IgG, IgM, IgA and IgE in the supernatant of cultivated spleen cells and serum from ZD and ZH mice were all lower than those of control mice. Thus, the level of zinc correlated with the defence against infection by A. cantonensis, due to the influence of zinc on the growth of mice and their production of IL-5, eosinophils and immunoglobulins.

Eosinophil chemoattracted by eotaxin from cerebrospinal fluid of mice infected with Angiostrongylus cantonensis assayed in a microchamber

When non-permissive hosts are infected with Angiostrongylus cantonensis, the migration of the worms to the brain and their subsequent development manifests as marked eosinophilic pleocytosis. We used microchambers to demonstrate direct eosinophil chemotactic activity by adding a variety of antibodies into cerebrospinal fluid (CSF) of BALB/c mice 21 days post-infection with A. cantonensis. The antibodies were directed to neutralize eotaxin, RANTES (regulated on activation, normal T-cells expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and platelet-activating factor (PAF), respectively. Eosinophil migration into the polycarbonate membrane covering CSF with anti-eotaxin or anti-MIP-1alpha antibodies was significantly lower than that for antibody-free CSF (Student's t test: p < 0.01, p < 0.05). We also collected CSF from mice 21 days after infection with 10, 20, 30, 40, and 50 third-stage larvae (L3) respectively for dose-dependent testing, and 40 L3 at days 7, 14, and 21 after infection for time-dependent testing. Chemokine production in CSF was affected by A. cantonensis infection intensity and post-infection time. In conclusion, eotaxin and MIP-1alpha released in the CSF of A. cantonensis-infected mice have eosinophil chemotactic activity in this in vitro assay.

Immuno-PCR for Detection of Antigen to Angiostrongylus cantonensis Circulating Fifth-Stage Worms

Background: Definitive diagnosis of infestation with Angiostrongylus cantonensis is difficult because the parasitic nematode is undetectable in the cerebrospinal fluid (CSF) of one-half of afflicted patients and the diagnostic sensitivity of ELISA for circulating worm antigens in patient sera is low. We studied immuno-PCR as a diagnostic tool.

Methods: We studied 30 controls and 60 afflicted patients (30 confirmed by parasitologic analysis of CSF). We used a monoclonal antibody to capture circulating A. cantonensis antigens in serum samples. A DNA label generated by PCR amplification with biotinylated primer was bound by use of streptavidin to a biotinylated third antibody. Circulating antigens sandwiched by monoclonal antibody were detected by PCR amplification of the DNA label.

Results: The detection limit of the ELISA was 100–1000 times higher than that of the immuno-PCR. The concentrations of circulating antigens in patients were markedly higher than those in controls (Wilcoxon rank-sum test, P &lt;0.001). At a cutoff of 0.1 ng/L, sensitivity and specificity for immunodiagnosis of patients with angiostrongyliasis by immuno-PCR were 98% (95% confidence interval, 91–99%) and 100% (93–100%), respectively. The test was positive in all parasitologically confirmed cases.

Conclusions: Immuno-PCR is a promising technique for diagnosis of A. cantonensis infestation.

Kinetics of change in the eotaxin concentration in serum and cerebrospinal fluid of mice infected with Angiostrongylus cantonensis

The kinetics of changes in the eotaxin concentration in the serum and cerebrospinal fluid (CSF) of BALB/c mice after infection with Angiostrongylus cantonensis and the correlation between the concentration of eotaxin and worm recovery were investigated. The mean concentration of eotaxin in serum of infected mice gradually increased from 46.3+/-6.5 pg/ml at week 0 to 104.9+/-44.8 pg/ml at week 3 after infection, while the mean eotaxin level in the CSF of infected mice rapidly increased from 18.7+/-2.1 pg/ml to 193.2+/-23.6 pg/ml 1 week after infection and then increased further to 507.8+/-167.9 pg/ml at week 3. The concentrations of eotaxin in the CSF of infected mice each week after infection were all significantly higher than those in serum ( P<0.0001). In parallel with the increase in eotaxin in the CSF, infected mice showed gradual increases in CSF eosinophilia and a reduction in intracranial worm recovery. The concentration of eotaxin in CSF was higher in infected mice with more worms in the brain, except when the number of worms in the brain was >30. In addition, when the worm counts in the brains of infected mice were <30, eotaxin concentrations in the CSF were positively correlated with worm counts in the brain ( P<0.001). Thus, the release of eotaxin in the CSF of mice infected with A. cantonensis observed in this study was time dependent and worm-load dependent, and in parallel with the increase in eotaxin in the CSF, and gradual decreases in worm counts in the brains of infected mice.

Haplorchis infections in intermediate hosts from a clonorchiasis endemic area in Meinung, Taiwan, Republic of China

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.

Clinical manifestations of strongyloidiasis in southern Taiwan

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.

Eosinophilic meningitis caused by Angiostrongylus cantonensis: report of 17 cases

PURPOSE

To describe two outbreaks of Angiostrongylus cantonensis infection that occurred in Kaohsiung, Taiwan, during 1998 and 1999, and to characterize the source of the outbreaks and the clinical manifestations of the disease.

SUBJECTS AND METHODS

We performed a retrospective cohort study among Thai laborers with eosinophilic meningitis who ate raw snails (Ampullarium canaliculatus), as well as an environmental surveillance of larvae in snails.

RESULTS

We enrolled 17 Thai laborers in whom severe headache and eosinophilia developed within 4 to 23 days after eating raw snails. Twelve (71%) developed eosinophilic meningitis. Third-stage larvae were found in the cerebrospinal fluids of 2 patients and in all 12 tested snails. Specific antibodies to A. cantonensis were detected in serum from 16 of the patients and in cerebrospinal fluid from 5 of the patients. Central nervous system manifestations included headache (n = 17 [100%]), fever (n = 11 [65%]), Brudzinski's sign/stiff neck (n = 11 [65%]), hyperesthesia (n = 3 [18%]), cranial nerve palsy (n = 2 [12%]), diplopia (n = 2 [12%]), and ataxia (n = 1 [6%]). Laboratory findings included peripheral eosinophilia (n = 15 [88%]) and cerebrospinal fluid eosinophilia (n = 12 [71%]); elevated immunoglobulin (Ig) E levels (n = 13 [100%]); and transient increases in white blood cell count (n = 7 [41%]) and in serum levels of creatine kinase (n = 7 [41%]), transaminase (n = 3 [18%]), and lactate dehydrogenase (n = 2 [12%]). The severity of illness and eosinophilia were correlated with the number of ingested snails. Meningeal and basal ganglion enhancement was noted on magnetic resonance imaging in several patients. Treatment with mebendazole combined with glucocorticosteroids appeared to shorten the course of the infection, but not the number of relapses. The eosinophil count fell to normal within 3 months, but IgE levels remained elevated for as long as 6 months. All patients recovered with minimal neurologic sequelae.

CONCLUSION

Eosinophilic meningitis caused by A. cantonensis should be considered in patients who have headache or central nervous system manifestations after eating raw snails.

Hepatic Schistosomiasis japonica in a patient with gallstones and bile duct stones--a case report

Schistosomiasis, a common parasitic disease in many countries, is found as imported cases in Taiwan. Responsible for human infections are five species, one of which, Schistosoma japonicum, is currently endemic in China and South-east Asia. Chronic infection with S. japonicum may lead to the development of liver fibrosis, calcification and portal hypertension. Under investigation by sonography and computed tomography (CT) scan, a peculiar "turtle-back" appearance of liver fibrosis and calcification may be found. Herein, we report a case referred to our department due to jaundice. The sonography of liver showed typical "turtle-back" appearance. Gallstones and bile duct stones were also found in this case. Surgical interventions with percutaneous transhepatic biliary drainage (PTBD), cholecystectomy and choledocholithotomy were performed to relieve the obstructive jaundice and remove the stones. There were no parasitic eggs in the extracted stones or in drained bile juice. However, deposits of calcified S. japonicum eggs in liver parenchyma and portal tracts were identified in liver biopsy. No special treatment was given for the schistosomiasis japonica because the calcified parasitic eggs were the sequelae of past infection.

An outbreak of meningitis caused by Angiostrongylus cantonensis in Kaohsiung

Eight Thai laborers developed meningitis after eating raw snails (Ampullarium canaliculatus) during the period from September 27 to October 6, 1998. The diagnosis of Angiostrongylus cantonensis infection was established in all patients by serologic studies of serum and cerebral spinal fluid (CSF). Clinical manifestations included meningitis, radiculitis and cranial nerve palsy. Symptoms included fever, headache, orbital pain, gastrointestinal upset, hyperesthesia, muscle weakness, skin rash and diplopia. Laboratory abnormalities included peripheral eosinophilia, CSF eosinophilia, transient elevation of liver enzymes and creatinine phosphokinase, elevation of IgE. No space occupying lesions were detected by magnetic resonance imaging of the brain. None of the patients developed severe sequelae during the 6-month follow-up except for occasional headache in one patient. This report also provides evidence that third stage larvae were present in the intermediate host, A. canaliculatus, which the laborers had eaten.