Integrative taxonomic approach of trypanosomes in the blood of rodents and soricids in Asian countries, with the description of three new species.

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.

Effects of age and splenectomy on heavy infection of Angiostrongylus cantonensis in rats.

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.

Brain magnetic resonance imaging abnormalities in eosinophilic meningitis caused by Angiostrongylus cantonensis 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.

Intestinal parasitic infection detected by stool examination in foreign laborers in Kaohsiung.

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.

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.

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.

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.

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).

Effects of Asian dust storm events on daily mortality in Taipei, Taiwan.

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.

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.

Treatment of Toxoplasma brain abscess with clindamycin and sulfadiazine in an AIDS patient with concurrent atypical Pneumocystis carinii pneumonia.

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.