Chia-Kwung Fan | Taipei Medical University (original) (raw)
Papers by Chia-Kwung Fan
![Research paper thumbnail of [Seroepidemiology of Toxoplasma gondii infection among Atayal aborigines and local animals in Nan-ao district, Ilan county and Jen-ai district, Nan-tou county, Taiwan]](https://attachments.academia-assets.com/43217923/thumbnails/1.jpg)
](The Kaohsiung journal of medical sciences
BACKGROUND: Toxoplasmosis is a worldwide infection. Most studies on toxoplasmosis are in women in... more BACKGROUND: Toxoplasmosis is a worldwide infection. Most studies on toxoplasmosis are in women in child bearing ages. We conducted an epidemiological survey on the population of the Isfahan Province to identify characteristics of the individuals associated with seropositivity.
![Research paper thumbnail of [Larval distribution in different organs of ICR strain mice infected with Toxocara canis]](https://a.academia-assets.com/images/blank-paper.jpg)
](The Kaohsiung journal of medical sciences, 1998
In this study 80 ICR mice were infected per os with 260 embryonated Toxocara canis eggs each thro... more In this study 80 ICR mice were infected per os with 260 embryonated Toxocara canis eggs each through a stomach tube. Ten mice were sacrificed at weekly intervals over an eight-week period. Internal organs including livers, lungs, hearts, spleens, kidneys, brains, and carcasses were pooled separately and T.canis larvae from each category treated with artificial digestive fluid were recovered and later collected by the Baermann technique. Larval distributions at a given week in different organs or in a given organ at different weeks were compared and analyzed. Results revealed that total larval recovery increased from week one (11.6%) to four(19.7%); thereafter it decreased gradually and dropped to 13.4% by week eight. Larval distribution in different organs varied with time. No larvae were recovered from the heart or spleen during the study period, except for a small number recovered from the spleen in the 4th and 5th weeks after infection. In general, the larvae were recovered mainl...
International immunopharmacology, 2015
Zerumbone is a sesquiterpene compound isolated from the rhizome of wild ginger, Zingiber zerumbet... more Zerumbone is a sesquiterpene compound isolated from the rhizome of wild ginger, Zingiber zerumbet Smith. The rhizomes of the plant are used as a spice and traditional medicine. Zerumbone was shown to possess anticarcinogenic, anti-inflammatory, and antioxidant properties. However, the antiallergic activity and the underlying mechanism of zerumbone have not been reported. Herein, we investigated the immunomodulatory effects of zerumbone on antigen-presenting dendritic cells (DCs) in vitro and its potential therapeutic effects against ovalbumin (OVA)-induced T helper 2 (Th2)-mediated asthma in mice. In the presence of zerumbone, lipopolysaccharide-activated bone marrow-derived DCs enhanced T cell proliferation and Th1 cell polarization in an allogeneic mixed lymphocyte reaction. In animal experiments, mice were sensitized and challenged with OVA, and were orally treated with different doses of zerumbone after sensitization. Circulating titers of OVA-specific antibodies, airway hyperre...
Parasite Immunology, 2004
The involvement of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in pathogenesis ... more The involvement of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in pathogenesis of toxocaral granulomatous hepatitis (TGH) in a murine host was quantitatively determined by biochemical, parasitological, pathological, and immunohistochemical assessments in a 42-week investigation. Mice were sacrificed for serum collection and histological processing as well as acid-pepsin digestion of the liver in a larval recovery study. Significantly increased levels of total serum NO were found in the trial, indirectly suggesting iNOS activation in the liver. iNOS reactivity was predominantly observed in infiltrating leucocytes in lesions and normal and apocrine-like cholangiocytes; in contrast, hepatocytes and multinucleated giant cells showed negative cytoplasmic staining in TGH. Strong iNOS-like reactivity was also detected on the body wall of larvae. The locations of NT reactivity were nearly identical to those of iNOS expression; infiltrating leucocytes or cholangiocytes stained for iNOS were also stained for NT in TGH. Enhanced iNOS expression, but not invading larvae ( r = 0·256, P = 0·211), seemed to play a certain role in pathological damage in TGH due to a significant correlation between iNOS expression and serum alanine aminotransferase (ALT) levels ( r = 0·593, P = 0·021) in the trial. Our present results indicate a potential therapeutic strategy for treatment of GH caused by other nematodes through manipulation of iNOS expression.
Parasite Immunology, 2008
Annals of Tropical Medicine & Parasitology, 2005
Seroepidemiology of Toxocara canis infection among adults of one ethnic Han and five aboriginal p... more Seroepidemiology of Toxocara canis infection among adults of one ethnic Han and five aboriginal populations residing in mountainous areas of Taiwan was conducted by detecting serum IgG (Ն1:64) using a T. canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. A short questionnaire interview was conducted to obtain data concerning their age, sex, occupation, consumption of raw pig liver, and possession of dogs. The overall seroprevalence (46.0%, 247 of 537) in the five aboriginal populations was significantly higher than that of ethnic Han population (30.2%, 13 of 43) (P ס 0.04). Age, but not sex, seemed to be a factor related to positive serology. Aboriginal adults who had histories of eating raw pig liver (odds ratio [OR] ס 1.65, P < 0.01), raising dogs (OR ס 1.76, P < 0.01), or whose occupation was a laborer (OR ס 1.78, P ס 0.01) seemed to be more apt to be infected by T. canis than those without such histories and unemployed persons. * Adjusted variables include age, risks factors, occupation, and ethnicity. † Adjusted variables include sex, risk factors, occupation, and ethnicity. ‡ Adjusted variables include sex, age, occupation, and ethnicity. § Adjusted variables include sex, age, risk factors, and ethnicity. ¶ Adjusted variables include sex, age, risk factors, and occupation.
Acta Tropica, 2013
Macrophages initiate, modulate, and also serve as final effector cells in immune responses during... more Macrophages initiate, modulate, and also serve as final effector cells in immune responses during the course of schistosomal infections. In this study, we investigated the gene expression profile and functional changes of macrophages in immune responses against the Schistosoma japonicum by microarray analysis. Hierarchical clustering analysis demonstrated that a significant switch in gene transformation associated with a type-1 response and linked with a type-2 cytokine phenotype occurs between 4.5 and 8 weeks post-infection. Moreover, the gene profiles at 3 later time-points following egg challenge were similar in complexity and magnitude. The data also showed that there were mostly inhibition of gene expression related TLR, IFN, MHC and TNFrsf at the switch between 4.5 and 8 weeks post-infection, It is suggested that these immunomodulatory genes may be down-regulated in defense against S. japonicum eggs and granuloma pathology. The induction of alternatively activated macrophage (AAM) was important for dampening the inflammation in hepatic granulomas and contributing to a decrease in cytotoxicity. The gene expressions involved in repair/remodeling during liver fibrosis were also observed after egg production. Understanding the immune mechanisms associated with parasitic resistance, pathology of parasite infection, and parasite growth will provide useful insight on host-schistosome interactions and for the control of schistosomiasis.
Background: Infection by Toxocara spp. is known to be significantly associated with partial epile... more Background: Infection by Toxocara spp. is known to be significantly associated
with partial epilepsy. It has become popular for people to raise dogs/cats as pets
and consume roasted meat/viscera, and the status of Toxocara spp. infection, epilepsy
awareness, and associated risk factors among the general population are currently
unknown in Taiwan.
Methods: A seroepidemiological investigation among 203 college students (CSs),
consisting of 110 males and 93 females with an average age of 21.5 ± 1.2 years, was
conducted in 2009 in Taipei City. A Western blot analysis based on excretory-secretory
antigens derived from Toxocara canis larvae (TcESs) was applied to determine
the positivity of serum immunoglobulin G antibodies. A self-administered questionnaire
was also given to obtain information about demographic characteristics,
epilepsy awareness, and risk factors. A logistic regression model was applied for the
statistical analysis using SPSS software.
Results: The overall seropositive rate of Toxocara spp. infection was 8.4%
(17/203). As to epilepsy awareness, a non-significantly higher seroprevalence was
found in CSs who claimed to "know" about epilepsy compared to those who did
not know (P > 0.05).
Conclusions: It appears that appropriate educational programs are urgently needed
to provide correct knowledge related to the prevention and control measures
against Toxocara spp. infections to avoid potential threats by this parasite to the
general population in Taiwan.
Journal of Microbiology, Immunology and Infection, 2014
Please cite this article in press as: Chen S-H, et al., An infant boy with widespread ecchymoses ... more Please cite this article in press as: Chen S-H, et al., An infant boy with widespread ecchymoses and severe eosinophilia, Journal of Microbiology, Immunology and Infection (2014), http://dx.
Introduction: Toxoplasma gondii infection has been described as the most widespread zoonotic infe... more Introduction: Toxoplasma gondii infection has been described as the most widespread zoonotic infection of humans and other
animals. Information concerning T. gondii infection among schoolchildren is unavailable in Lagos City, Nigeria. Methods: This crosssectional
study investigated the seroprevalence and risk factors associated with T. gondii infection among primary schoolchildren
(PSC) from a community located in the center of Lagos, southern Nigeria, from November 2013 to March 2014. A total of 382 PSC
were screened for the presence of sera anti-T. gondii antibodies using a latex agglutination test (TOXO Test-MT, Tokyo, Japan). A
cutoff titer of ≥ 1:32 was considered positive, while titers ≥ 1:1,024 indicated high responders. Questionnaires were also used to obtain
data on possible risk factors from parents/guardians. Results: The overall seroprevalence was 24% (91/382), and 83.5% (76/91) of
seropositive PSC were classifi ed as high responders. Among the risk factors tested, including contact with cats and soil, consumption
of raw meat and vegetables, and drinking unboiled water, none showed statistical signifi cance after multivariate adjustment. No
associations were observed among age, gender, body mass index (BMI), and parents’ occupation/educational level. Conclusions: The
fi ndings in this study show evidence of active infection, and hence, there is need for urgent preventive measures in this city. Further
investigation is required to clarify the transmission routes. Policy makers also need to initiate prevention and control programs to
protect pregnant women and immunocompromised patients in particular because they are more severely affected by T. gondii infection.
Herein, we determined the seroprevalence, seroconversion, and risk factors associated with Toxopl... more Herein, we determined the seroprevalence, seroconversion, and risk factors associated
with Toxoplasma gondii (T. gondii) infection among pregnant women in Taipei, Taiwan. Pregnant women
attending antenatal consultation in a Taipei medical center were invited, and 104 women completed
a self-administered structured questionnaire. Venous blood samples were collected during the first and
third trimester after consent was obtained. Serum IgG and IgM antibodies (Abs) as well as IgG avidity
were analyzed using an enzyme-linked fluorescent assay. Of the samples collected in the first trimester,
seven were seropositive for IgG Abs and one was seropositive for IgG ＋ IgM Abs with a borderline
avidity index, resulting in an overall seroprevalence of 7.7z. No statistically significant association was
found between toxoplasmosis and age, pregnancy history, or any risk factors. Seroconversion was not
detected from paired sera between the first and third trimesters. Pregnant women with senior high
school education level or those who claimed to knowing Toxoplasma exhibited a significantly higher
seroprevalence than those with bachelor degree (P ＝ 0.05) or those who claimed not to have this
knowledge (P ＝ 0.05). Therefore, failure to understand the importance of T. gondii infection and the
prevention measures resulted in the development of toxoplasmosis among these women.
Background: Although malaria control programs have made rapid progress recently, they neglect imp... more Background: Although malaria control programs have made rapid progress recently, they
neglect important social and behavioral factors associated with the disease. Social, political,
and cultural factors are involved in malaria control, and individuals in a community may be
comfortable in behaving in ways that, to an outsider, may seem contrary to commonly held
perceptions. Malaria control efforts can no longer afford to overlook the multidimensional human
contexts that create and support varying notions of malaria and its prevention, treatment,
and control. This study aimed to assess the knowledge and perceptions of malaria
issues in the community, and to identify practices that support or hinder the progress of malaria
control programs.Methods: A triangulation study involving individual interviews, focus group discussions, and observatory
analysis between 2003 and 2010 at Lomahasha, a malarious community on the
eastern border of Swaziland and Mozambique, was conducted.
Results: Results indicated that a high knowledge level and good perception of the disease were
observed in the age group of < 40 years, contrary to those in higher age groups, among the
Lomahasha community members. However, behavior of certain community groups includes
practices that are not supportive of the national control program’s aspirations, such as delay
in seeking medical attention, staying outdoors until late, maintaining stagnant water in roadside
excavations, and seeking medical assistance from wrong sources. Malpractices are more
commonly observed among men, boys, and those who drink alcohol.
Conclusion: This study suggests a thorough community diagnosis before all intervention programs
for malaria control are instituted.
Toxocara canis and T. cati are highly prevalent nematode infections of the intestines of dogs and... more Toxocara canis and T. cati are highly prevalent nematode infections
of the intestines of dogs and cats. In paratenic hosts,
larvae do not mature in the intestine but instead migrate
through the somatic tissues and organs of the body. The presence
of these migrating larvae can contribute to pathology.
Toxocara larvae can invade the brains of humans, and while
case descriptions of cerebral toxocariasis are historically rare, improved
diagnosis and greater awareness have contributed to increased
detection. Despite this, cerebral or neurological toxocariasis
(NT) remains a poorly understood phenomenon. Furthermore,
our understanding of cognitive deficits due to toxocariasis in human
populations remains particularly deficient. Recent data describe
an enhanced expression of biomarkers associated with
brain injury, such as GFAP, APP, transforming growth factor
1 (TGF-1), NF-L, S100B, tTG, and p-tau, in mice receiving
even low doses of Toxocara ova. Finally, this review outlines a
hypothesis to explore the relationship between the presence of T.
canis larvae in the brain and the progression of Alzheimer’s disease
(AD) due to enhanced AD-associated neurodegenerative biomarker
expression.
tIn this study, we investigated the seroprevalence of Toxocara canis infection in southern Nigeri... more tIn this study, we investigated the seroprevalence of Toxocara canis infection in southern Nigeria, whichpreviously was unknown, in addition to evaluating disease awareness and potential risk factors forschoolchildren in an urban slum community. In total, 366 primary schoolchildren were investigated forthe presence of anti-Toxocara IgG antibodies. Blood was collected and screened by a Western blot anal-ysis based on the excretory–secretory antigens of larval T. canis (TcES), targeting low molecular weightbands of 24–35 kDa specific for T. canis. Children were considered seropositive if their serum reactedwith TcES when diluted to a titer of 1:32. Questionnaires concerning possible risk factors were givento the schoolchildren to acquire data on this infection. The overall seroprevalence of Toxocara infectionwas 86.1% (315/366). The logistic regression analysis of risk factors showed that children’s age (oddsratio (OR) = 2.88, 95% confidence interval (CI) = 1.08–7.66, p = 0.03), contact with dogs (OR = 0.51, 95%CI = 0.28–0.94, p = 0.03), the age of the dog (OR = 0.34, 95% CI = 0.18–0.68, p = 0.002), the feeding locationof the dog (OR = 0.31, 95% CI = 0.12–0.79, p = 0.01), the consumption of raw vegetables (OR = 0.89, 95%CI = 0.54–1.48, p = 0.004), and the drinking of unboiled water (OR = 0.48, 95% CI = 0.26–0.90, p = 0.02) wererisk factors associated with Toxocara infection. Although there was a high awareness of dogs being hostsof some parasites in this study, not much was known about T. canis. This is the first serological investi-gation of T. canis infection among primary schoolchildren in southern Nigeria. The high seroprevalencerecorded is an indication of high transmission with the consequent risk of visceral or ocular larval migransand neurologic toxocariasis in these children. Our findings suggest the need for prompt interventionalmeasures, particularly health education on personal hygiene.
Although Toxoplasma gondii infection is commonly prevalent in the tropical/subtropical regions, t... more Although Toxoplasma gondii infection is commonly prevalent in the tropical/subtropical
regions, the prevalence of toxoplasmosis in the Republic of theMarshall Islands (RMI) remains unclear.
A seroepidemiological survey was undertaken for investigating T. gondii infection in primary school
children (PSC) using the latex agglutination (LA) test in the capital area of RMI. Information on demographic
characteristics and environmental risk factors was collected via a structured questionnaire.
Logistic regression model was applied for multivariate analysis. The overall infection rate of T. gondii
was found to be 54.8z. Significant gender differences were found at different urbanization levels. PSC
with LA titers ofÆ1:1,024, indicating high responders, were found to be younger age group than others
(8.7 years vs. 10.3 years, P ＝ 0.003); moreover, infection rates among both age groups as well as high
responders showed a decreasing trend with age. Multivariate analysis revealed that residing in urban
rather than suburban settings was associated with increased risk of infection (P ＝ 0.04). No associations
were found between raw meat consumption, drinking unboiled water, and cleaning of cat hutch
using gloves. This is the first serological survey of T. gondii infection among PSC in RMI and could
help in the development of strategies in the future for disease prevention and control of T. gondii transmission.
The seroprevalence of IgG antibodies against Toxoplasma gondii was assessed in 169 adult non-hemo... more The seroprevalence of IgG antibodies against Toxoplasma gondii was assessed in
169 adult non-hemophiliac Japanese patients infected with human immunodeficiency
virus. The seroprevalence of T. gondii infection was only 14.2%, which was similar
to findings from the USA and lower than that reported for most other countries. The
positive ratio of T. gondii IgG antibodies was significantly higher in patients aged
≥ 40 years (21.0% vs. 7.9%, p=0.01) with < 200 CD4+ cells /μL (20.5% vs. 9.4%,
p=0.04). Group analysis showed that seropositivity did not differ according to
sexuality. The ratios of positivity for hepatitis B surface antigen, hepatitis B surface
antibody, hepatitis C antibody, serological findings for syphilis and the findings of the
Treponema pallidum hemaggulation test were not associated the seroprevalence of
IgG antibodies against T. gondii.
These results indicate that patients in Japan with lesions of the central nervous
system and antibodies against T. gondii are highly likely to have toxoplasmosis.
Infection with T. gondii should be carefully assessed in elderly Japanese patients who
are infected with human immunodeficiency virus.
Background: Toxocariasis, which is predominantly caused by Toxocara canis (T. canis) infection, i... more Background: Toxocariasis, which is predominantly caused by Toxocara canis (T. canis) infection, is a common
zoonotic parasitosis worldwide; however, the status of toxocariasis endemicity in the Republic of the Marshall
Islands (RMI) remains unknown.
Methods: A seroepidemiological investigation was conducted among 166 primary school children (PSC) aged 7–12
years from the capital area of the RMI. Western blots based the excretory-secretory antigens of larval T. canis (TcES)
was employed, and children were considered seropositive if their serum reacted with TcES when diluted at a titer
of 1:64. Information regarding demographic characteristics of and environmental risk factors affecting these children
was collected using a structured questionnaire. A logistic regression model was applied to conduct a multivariate
analysis.
Results: The overall seropositive rate of T. canis infection was 86.75% (144/166). In the univariate analysis, PSC who
exhibited a history of feeding dogs at home (OR = 5.52, 95% CI = 1.15–26.61, p = 0.02) and whose parents were
employed as nonskilled workers (OR = 2.86, 95% CI = 1.08–7.60, p = 0.03) demonstrated a statistically elevated risk of
contracting T. canis infections. Cleaning dog huts with gloves might prevent infection, but yielded nonsignificant
effects. The multivariate analysis indicated that parental occupation was the critical risk factor in this study because
its effect remained significant after adjusting for other variables; by contrast, the effect of dog feeding became
nonsignificant because of other potential confounding factors. No associations were observed among gender,
age, consuming raw meat or vegetables, drinking unboiled water, cleaning dog huts with gloves, or touching soil.
Conclusions: This is the first serological investigation of T. canis infection among PSC in the RMI. The high
seroprevalence indicates the commonness of T. canis transmission and possible human risk. The fundamental
information that the present study provides regarding T. canis epidemiology can facilitate developing strategies
for disease prevention and control.
The first case report of acquired platelet dysfunction with eosinophilia (APDE) in Taiwan.
The Kaohsiung journal of medical sciences
BACKGROUND: Toxoplasmosis is a worldwide infection. Most studies on toxoplasmosis are in women in... more BACKGROUND: Toxoplasmosis is a worldwide infection. Most studies on toxoplasmosis are in women in child bearing ages. We conducted an epidemiological survey on the population of the Isfahan Province to identify characteristics of the individuals associated with seropositivity.
The Kaohsiung journal of medical sciences, 1998
In this study 80 ICR mice were infected per os with 260 embryonated Toxocara canis eggs each thro... more In this study 80 ICR mice were infected per os with 260 embryonated Toxocara canis eggs each through a stomach tube. Ten mice were sacrificed at weekly intervals over an eight-week period. Internal organs including livers, lungs, hearts, spleens, kidneys, brains, and carcasses were pooled separately and T.canis larvae from each category treated with artificial digestive fluid were recovered and later collected by the Baermann technique. Larval distributions at a given week in different organs or in a given organ at different weeks were compared and analyzed. Results revealed that total larval recovery increased from week one (11.6%) to four(19.7%); thereafter it decreased gradually and dropped to 13.4% by week eight. Larval distribution in different organs varied with time. No larvae were recovered from the heart or spleen during the study period, except for a small number recovered from the spleen in the 4th and 5th weeks after infection. In general, the larvae were recovered mainl...
International immunopharmacology, 2015
Zerumbone is a sesquiterpene compound isolated from the rhizome of wild ginger, Zingiber zerumbet... more Zerumbone is a sesquiterpene compound isolated from the rhizome of wild ginger, Zingiber zerumbet Smith. The rhizomes of the plant are used as a spice and traditional medicine. Zerumbone was shown to possess anticarcinogenic, anti-inflammatory, and antioxidant properties. However, the antiallergic activity and the underlying mechanism of zerumbone have not been reported. Herein, we investigated the immunomodulatory effects of zerumbone on antigen-presenting dendritic cells (DCs) in vitro and its potential therapeutic effects against ovalbumin (OVA)-induced T helper 2 (Th2)-mediated asthma in mice. In the presence of zerumbone, lipopolysaccharide-activated bone marrow-derived DCs enhanced T cell proliferation and Th1 cell polarization in an allogeneic mixed lymphocyte reaction. In animal experiments, mice were sensitized and challenged with OVA, and were orally treated with different doses of zerumbone after sensitization. Circulating titers of OVA-specific antibodies, airway hyperre...
Parasite Immunology, 2004
The involvement of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in pathogenesis ... more The involvement of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in pathogenesis of toxocaral granulomatous hepatitis (TGH) in a murine host was quantitatively determined by biochemical, parasitological, pathological, and immunohistochemical assessments in a 42-week investigation. Mice were sacrificed for serum collection and histological processing as well as acid-pepsin digestion of the liver in a larval recovery study. Significantly increased levels of total serum NO were found in the trial, indirectly suggesting iNOS activation in the liver. iNOS reactivity was predominantly observed in infiltrating leucocytes in lesions and normal and apocrine-like cholangiocytes; in contrast, hepatocytes and multinucleated giant cells showed negative cytoplasmic staining in TGH. Strong iNOS-like reactivity was also detected on the body wall of larvae. The locations of NT reactivity were nearly identical to those of iNOS expression; infiltrating leucocytes or cholangiocytes stained for iNOS were also stained for NT in TGH. Enhanced iNOS expression, but not invading larvae ( r = 0·256, P = 0·211), seemed to play a certain role in pathological damage in TGH due to a significant correlation between iNOS expression and serum alanine aminotransferase (ALT) levels ( r = 0·593, P = 0·021) in the trial. Our present results indicate a potential therapeutic strategy for treatment of GH caused by other nematodes through manipulation of iNOS expression.
Parasite Immunology, 2008
Annals of Tropical Medicine & Parasitology, 2005
Seroepidemiology of Toxocara canis infection among adults of one ethnic Han and five aboriginal p... more Seroepidemiology of Toxocara canis infection among adults of one ethnic Han and five aboriginal populations residing in mountainous areas of Taiwan was conducted by detecting serum IgG (Ն1:64) using a T. canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. A short questionnaire interview was conducted to obtain data concerning their age, sex, occupation, consumption of raw pig liver, and possession of dogs. The overall seroprevalence (46.0%, 247 of 537) in the five aboriginal populations was significantly higher than that of ethnic Han population (30.2%, 13 of 43) (P ס 0.04). Age, but not sex, seemed to be a factor related to positive serology. Aboriginal adults who had histories of eating raw pig liver (odds ratio [OR] ס 1.65, P < 0.01), raising dogs (OR ס 1.76, P < 0.01), or whose occupation was a laborer (OR ס 1.78, P ס 0.01) seemed to be more apt to be infected by T. canis than those without such histories and unemployed persons. * Adjusted variables include age, risks factors, occupation, and ethnicity. † Adjusted variables include sex, risk factors, occupation, and ethnicity. ‡ Adjusted variables include sex, age, occupation, and ethnicity. § Adjusted variables include sex, age, risk factors, and ethnicity. ¶ Adjusted variables include sex, age, risk factors, and occupation.
Acta Tropica, 2013
Macrophages initiate, modulate, and also serve as final effector cells in immune responses during... more Macrophages initiate, modulate, and also serve as final effector cells in immune responses during the course of schistosomal infections. In this study, we investigated the gene expression profile and functional changes of macrophages in immune responses against the Schistosoma japonicum by microarray analysis. Hierarchical clustering analysis demonstrated that a significant switch in gene transformation associated with a type-1 response and linked with a type-2 cytokine phenotype occurs between 4.5 and 8 weeks post-infection. Moreover, the gene profiles at 3 later time-points following egg challenge were similar in complexity and magnitude. The data also showed that there were mostly inhibition of gene expression related TLR, IFN, MHC and TNFrsf at the switch between 4.5 and 8 weeks post-infection, It is suggested that these immunomodulatory genes may be down-regulated in defense against S. japonicum eggs and granuloma pathology. The induction of alternatively activated macrophage (AAM) was important for dampening the inflammation in hepatic granulomas and contributing to a decrease in cytotoxicity. The gene expressions involved in repair/remodeling during liver fibrosis were also observed after egg production. Understanding the immune mechanisms associated with parasitic resistance, pathology of parasite infection, and parasite growth will provide useful insight on host-schistosome interactions and for the control of schistosomiasis.
Background: Infection by Toxocara spp. is known to be significantly associated with partial epile... more Background: Infection by Toxocara spp. is known to be significantly associated
with partial epilepsy. It has become popular for people to raise dogs/cats as pets
and consume roasted meat/viscera, and the status of Toxocara spp. infection, epilepsy
awareness, and associated risk factors among the general population are currently
unknown in Taiwan.
Methods: A seroepidemiological investigation among 203 college students (CSs),
consisting of 110 males and 93 females with an average age of 21.5 ± 1.2 years, was
conducted in 2009 in Taipei City. A Western blot analysis based on excretory-secretory
antigens derived from Toxocara canis larvae (TcESs) was applied to determine
the positivity of serum immunoglobulin G antibodies. A self-administered questionnaire
was also given to obtain information about demographic characteristics,
epilepsy awareness, and risk factors. A logistic regression model was applied for the
statistical analysis using SPSS software.
Results: The overall seropositive rate of Toxocara spp. infection was 8.4%
(17/203). As to epilepsy awareness, a non-significantly higher seroprevalence was
found in CSs who claimed to "know" about epilepsy compared to those who did
not know (P > 0.05).
Conclusions: It appears that appropriate educational programs are urgently needed
to provide correct knowledge related to the prevention and control measures
against Toxocara spp. infections to avoid potential threats by this parasite to the
general population in Taiwan.
Journal of Microbiology, Immunology and Infection, 2014
Please cite this article in press as: Chen S-H, et al., An infant boy with widespread ecchymoses ... more Please cite this article in press as: Chen S-H, et al., An infant boy with widespread ecchymoses and severe eosinophilia, Journal of Microbiology, Immunology and Infection (2014), http://dx.
Introduction: Toxoplasma gondii infection has been described as the most widespread zoonotic infe... more Introduction: Toxoplasma gondii infection has been described as the most widespread zoonotic infection of humans and other
animals. Information concerning T. gondii infection among schoolchildren is unavailable in Lagos City, Nigeria. Methods: This crosssectional
study investigated the seroprevalence and risk factors associated with T. gondii infection among primary schoolchildren
(PSC) from a community located in the center of Lagos, southern Nigeria, from November 2013 to March 2014. A total of 382 PSC
were screened for the presence of sera anti-T. gondii antibodies using a latex agglutination test (TOXO Test-MT, Tokyo, Japan). A
cutoff titer of ≥ 1:32 was considered positive, while titers ≥ 1:1,024 indicated high responders. Questionnaires were also used to obtain
data on possible risk factors from parents/guardians. Results: The overall seroprevalence was 24% (91/382), and 83.5% (76/91) of
seropositive PSC were classifi ed as high responders. Among the risk factors tested, including contact with cats and soil, consumption
of raw meat and vegetables, and drinking unboiled water, none showed statistical signifi cance after multivariate adjustment. No
associations were observed among age, gender, body mass index (BMI), and parents’ occupation/educational level. Conclusions: The
fi ndings in this study show evidence of active infection, and hence, there is need for urgent preventive measures in this city. Further
investigation is required to clarify the transmission routes. Policy makers also need to initiate prevention and control programs to
protect pregnant women and immunocompromised patients in particular because they are more severely affected by T. gondii infection.
Herein, we determined the seroprevalence, seroconversion, and risk factors associated with Toxopl... more Herein, we determined the seroprevalence, seroconversion, and risk factors associated
with Toxoplasma gondii (T. gondii) infection among pregnant women in Taipei, Taiwan. Pregnant women
attending antenatal consultation in a Taipei medical center were invited, and 104 women completed
a self-administered structured questionnaire. Venous blood samples were collected during the first and
third trimester after consent was obtained. Serum IgG and IgM antibodies (Abs) as well as IgG avidity
were analyzed using an enzyme-linked fluorescent assay. Of the samples collected in the first trimester,
seven were seropositive for IgG Abs and one was seropositive for IgG ＋ IgM Abs with a borderline
avidity index, resulting in an overall seroprevalence of 7.7z. No statistically significant association was
found between toxoplasmosis and age, pregnancy history, or any risk factors. Seroconversion was not
detected from paired sera between the first and third trimesters. Pregnant women with senior high
school education level or those who claimed to knowing Toxoplasma exhibited a significantly higher
seroprevalence than those with bachelor degree (P ＝ 0.05) or those who claimed not to have this
knowledge (P ＝ 0.05). Therefore, failure to understand the importance of T. gondii infection and the
prevention measures resulted in the development of toxoplasmosis among these women.
Background: Although malaria control programs have made rapid progress recently, they neglect imp... more Background: Although malaria control programs have made rapid progress recently, they
neglect important social and behavioral factors associated with the disease. Social, political,
and cultural factors are involved in malaria control, and individuals in a community may be
comfortable in behaving in ways that, to an outsider, may seem contrary to commonly held
perceptions. Malaria control efforts can no longer afford to overlook the multidimensional human
contexts that create and support varying notions of malaria and its prevention, treatment,
and control. This study aimed to assess the knowledge and perceptions of malaria
issues in the community, and to identify practices that support or hinder the progress of malaria
control programs.Methods: A triangulation study involving individual interviews, focus group discussions, and observatory
analysis between 2003 and 2010 at Lomahasha, a malarious community on the
eastern border of Swaziland and Mozambique, was conducted.
Results: Results indicated that a high knowledge level and good perception of the disease were
observed in the age group of < 40 years, contrary to those in higher age groups, among the
Lomahasha community members. However, behavior of certain community groups includes
practices that are not supportive of the national control program’s aspirations, such as delay
in seeking medical attention, staying outdoors until late, maintaining stagnant water in roadside
excavations, and seeking medical assistance from wrong sources. Malpractices are more
commonly observed among men, boys, and those who drink alcohol.
Conclusion: This study suggests a thorough community diagnosis before all intervention programs
for malaria control are instituted.
Toxocara canis and T. cati are highly prevalent nematode infections of the intestines of dogs and... more Toxocara canis and T. cati are highly prevalent nematode infections
of the intestines of dogs and cats. In paratenic hosts,
larvae do not mature in the intestine but instead migrate
through the somatic tissues and organs of the body. The presence
of these migrating larvae can contribute to pathology.
Toxocara larvae can invade the brains of humans, and while
case descriptions of cerebral toxocariasis are historically rare, improved
diagnosis and greater awareness have contributed to increased
detection. Despite this, cerebral or neurological toxocariasis
(NT) remains a poorly understood phenomenon. Furthermore,
our understanding of cognitive deficits due to toxocariasis in human
populations remains particularly deficient. Recent data describe
an enhanced expression of biomarkers associated with
brain injury, such as GFAP, APP, transforming growth factor
1 (TGF-1), NF-L, S100B, tTG, and p-tau, in mice receiving
even low doses of Toxocara ova. Finally, this review outlines a
hypothesis to explore the relationship between the presence of T.
canis larvae in the brain and the progression of Alzheimer’s disease
(AD) due to enhanced AD-associated neurodegenerative biomarker
expression.
tIn this study, we investigated the seroprevalence of Toxocara canis infection in southern Nigeri... more tIn this study, we investigated the seroprevalence of Toxocara canis infection in southern Nigeria, whichpreviously was unknown, in addition to evaluating disease awareness and potential risk factors forschoolchildren in an urban slum community. In total, 366 primary schoolchildren were investigated forthe presence of anti-Toxocara IgG antibodies. Blood was collected and screened by a Western blot anal-ysis based on the excretory–secretory antigens of larval T. canis (TcES), targeting low molecular weightbands of 24–35 kDa specific for T. canis. Children were considered seropositive if their serum reactedwith TcES when diluted to a titer of 1:32. Questionnaires concerning possible risk factors were givento the schoolchildren to acquire data on this infection. The overall seroprevalence of Toxocara infectionwas 86.1% (315/366). The logistic regression analysis of risk factors showed that children’s age (oddsratio (OR) = 2.88, 95% confidence interval (CI) = 1.08–7.66, p = 0.03), contact with dogs (OR = 0.51, 95%CI = 0.28–0.94, p = 0.03), the age of the dog (OR = 0.34, 95% CI = 0.18–0.68, p = 0.002), the feeding locationof the dog (OR = 0.31, 95% CI = 0.12–0.79, p = 0.01), the consumption of raw vegetables (OR = 0.89, 95%CI = 0.54–1.48, p = 0.004), and the drinking of unboiled water (OR = 0.48, 95% CI = 0.26–0.90, p = 0.02) wererisk factors associated with Toxocara infection. Although there was a high awareness of dogs being hostsof some parasites in this study, not much was known about T. canis. This is the first serological investi-gation of T. canis infection among primary schoolchildren in southern Nigeria. The high seroprevalencerecorded is an indication of high transmission with the consequent risk of visceral or ocular larval migransand neurologic toxocariasis in these children. Our findings suggest the need for prompt interventionalmeasures, particularly health education on personal hygiene.
Although Toxoplasma gondii infection is commonly prevalent in the tropical/subtropical regions, t... more Although Toxoplasma gondii infection is commonly prevalent in the tropical/subtropical
regions, the prevalence of toxoplasmosis in the Republic of theMarshall Islands (RMI) remains unclear.
A seroepidemiological survey was undertaken for investigating T. gondii infection in primary school
children (PSC) using the latex agglutination (LA) test in the capital area of RMI. Information on demographic
characteristics and environmental risk factors was collected via a structured questionnaire.
Logistic regression model was applied for multivariate analysis. The overall infection rate of T. gondii
was found to be 54.8z. Significant gender differences were found at different urbanization levels. PSC
with LA titers ofÆ1:1,024, indicating high responders, were found to be younger age group than others
(8.7 years vs. 10.3 years, P ＝ 0.003); moreover, infection rates among both age groups as well as high
responders showed a decreasing trend with age. Multivariate analysis revealed that residing in urban
rather than suburban settings was associated with increased risk of infection (P ＝ 0.04). No associations
were found between raw meat consumption, drinking unboiled water, and cleaning of cat hutch
using gloves. This is the first serological survey of T. gondii infection among PSC in RMI and could
help in the development of strategies in the future for disease prevention and control of T. gondii transmission.
The seroprevalence of IgG antibodies against Toxoplasma gondii was assessed in 169 adult non-hemo... more The seroprevalence of IgG antibodies against Toxoplasma gondii was assessed in
169 adult non-hemophiliac Japanese patients infected with human immunodeficiency
virus. The seroprevalence of T. gondii infection was only 14.2%, which was similar
to findings from the USA and lower than that reported for most other countries. The
positive ratio of T. gondii IgG antibodies was significantly higher in patients aged
≥ 40 years (21.0% vs. 7.9%, p=0.01) with < 200 CD4+ cells /μL (20.5% vs. 9.4%,
p=0.04). Group analysis showed that seropositivity did not differ according to
sexuality. The ratios of positivity for hepatitis B surface antigen, hepatitis B surface
antibody, hepatitis C antibody, serological findings for syphilis and the findings of the
Treponema pallidum hemaggulation test were not associated the seroprevalence of
IgG antibodies against T. gondii.
These results indicate that patients in Japan with lesions of the central nervous
system and antibodies against T. gondii are highly likely to have toxoplasmosis.
Infection with T. gondii should be carefully assessed in elderly Japanese patients who
are infected with human immunodeficiency virus.
Background: Toxocariasis, which is predominantly caused by Toxocara canis (T. canis) infection, i... more Background: Toxocariasis, which is predominantly caused by Toxocara canis (T. canis) infection, is a common
zoonotic parasitosis worldwide; however, the status of toxocariasis endemicity in the Republic of the Marshall
Islands (RMI) remains unknown.
Methods: A seroepidemiological investigation was conducted among 166 primary school children (PSC) aged 7–12
years from the capital area of the RMI. Western blots based the excretory-secretory antigens of larval T. canis (TcES)
was employed, and children were considered seropositive if their serum reacted with TcES when diluted at a titer
of 1:64. Information regarding demographic characteristics of and environmental risk factors affecting these children
was collected using a structured questionnaire. A logistic regression model was applied to conduct a multivariate
analysis.
Results: The overall seropositive rate of T. canis infection was 86.75% (144/166). In the univariate analysis, PSC who
exhibited a history of feeding dogs at home (OR = 5.52, 95% CI = 1.15–26.61, p = 0.02) and whose parents were
employed as nonskilled workers (OR = 2.86, 95% CI = 1.08–7.60, p = 0.03) demonstrated a statistically elevated risk of
contracting T. canis infections. Cleaning dog huts with gloves might prevent infection, but yielded nonsignificant
effects. The multivariate analysis indicated that parental occupation was the critical risk factor in this study because
its effect remained significant after adjusting for other variables; by contrast, the effect of dog feeding became
nonsignificant because of other potential confounding factors. No associations were observed among gender,
age, consuming raw meat or vegetables, drinking unboiled water, cleaning dog huts with gloves, or touching soil.
Conclusions: This is the first serological investigation of T. canis infection among PSC in the RMI. The high
seroprevalence indicates the commonness of T. canis transmission and possible human risk. The fundamental
information that the present study provides regarding T. canis epidemiology can facilitate developing strategies
for disease prevention and control.
The first case report of acquired platelet dysfunction with eosinophilia (APDE) in Taiwan.