In malaria-endemic areas, by young adulthood people have developed functional immunity to malaria. However, during pregnancy this immunity is breached and infection occurs, leading to increased risks for mother and child. In the past this effect has been attributed to nonspecific immunosuppression, but recent research has revealed a specific pathogenic mechanism, involving the adherence of rare parasite variants to the placenta. This commentary explores the current state of research in this area and proposes a model of immune evasion and placental colonization. This model points the way to the development of future therapeutic interventions.
Female ; Humans ; Malaria, Falciparum - immunology ; Pregnancy ; Pregnancy Complications ; Parasitic - immunology

The medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. Ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. Loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. Blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of hides. However, major losses caused by ticks are due to their ability to transmit protozoan, rickettsial and viral diseases of livestock, which are of great economic importance world-wide. There are quite a few methods for controlling ticks, but every method has certain shortcomings. The present review is focused on ticks importance and their control.
Animals ; Animals, Domestic ; immunology ; parasitology ; Humans ; Insecticides ; Parasitic Diseases ; prevention & control ; Ticks ; immunology ; Vaccines ; therapeutic use

Cryptosporidium, a coccidian parasite first described by Tyzzer (1907) from a laboratory mouse, has become an important human enteric pathogen causing overwhelming diarrhea especially in immunocompromised patients such as AIDS. This parasite has been reported from over 20 countries and is recognized as a cosmopolitan species. In Korea, however, there has been no report on human as well as animal cryptosporidiosis. This study was performed so as to verify the presence of Cryptosporidium in Korea by activating the parasite from laboratory mice by immunosuppression. Total 65 conventionally-bred ICR mice including a control (5 mice) and 3 experimental groups (20 each) were used for this study. Group I was immunosuppressed with prednisolone injection (1 mg IM, every other day) for 7 weeks. Group II (prednisolone injection and tetracycline administration) and Group III (prednisolone injection and trimethoprim-sulfamethoxazole administration) were prepared to observe the effect of antibacterial agents on the activation of cryptosporidiosis. In fecal examinations of mice Cryptosporidium oocysts (4-6 microns in size) were detected from 1 week after the start of immunosuppression and the mice began to die. In H-E stained tissue sections of the lower jejunum, numerous very small (2-4 microns), dense, ovoid or spherical, slightly basophilic bodies were seen attached on the free border of mucosal epithelial cells. In scanning and transmission electron microscopic observations, these organisms were identified as various developmental stages of Cryptosporidium. The species is considered to be C. parvum.(ABSTRACT TRUNCATED AT 250 WORDS)
Cryptosporidiosis-etiology ; Cryptosporidiosis-immunology ; Cryptosporidium-growth-and-development ; English-Abstract ; Immune-Tolerance ; Intestinal-Diseases,-Parasitic-etiology ; Intestinal-Diseases,-Parasitic-immunology ; Mice- ; Mice,-Inbred-ICR ; *Cryptosporidiosis-parasitology ; *Cryptosporidium-pathogenicity ; *Immunosuppression- ; *Intestinal-Diseases,-Parasitic-parasitology

The present study reports a human case of cutaneous gnathostomiasis with recurrent migratory nodule and persistent eosinophilia in China. A 52-year-old woman from Henan Province, central China, presented with recurrent migratory reddish swelling and subcutaneous nodule in the left upper arm and on the back for 3 months. Blood examination showed eosinophila (21.2%), and anti-sparganum antibodies were positive. Skin biopsy of the lesion and histopathological examinations revealed dermal infiltrates of eosinophils but did not show any parasites. Thus, the patient was first diagnosed as sparganosis; however, new migratory swellings occurred after treatment with praziquantel for 3 days. On further inquiring, she recalled having eaten undercooked eels and specific antibodies to the larvae of Gnathostoma spinigerum were detected. The patient was definitely diagnosed as cutaneous gnathostomiasis caused by Gnathostoma sp. and treated with albendazole (1,000 mg/day) for 15 days, and the subsequent papule and blister developed after the treatment. After 1 month, laboratory findings indicated a reduced eosinophil count (3.3%). At her final follow-up 18 months later, the patient had no further symptoms and anti-Gnathostoma antibodies became negative. Conclusively, the present study is the first report on a human case of cutaneous gnathostomiasis in Henan Province, China, based on the past history (eating undercooked eels), clinical manifestations (migratory subcutaneous nodule and persistent eosinophilia), and a serological finding (positive for specific anti-Gnathostoma antibodies).
Animals ; Anthelmintics/therapeutic use ; Antibodies, Helminth/immunology ; China ; Eosinophilia/diagnosis/drug therapy/immunology/*parasitology ; Female ; Gnathostoma/immunology/*isolation & purification ; Gnathostomiasis/diagnosis/drug therapy/immunology/*parasitology ; Humans ; Middle Aged ; Skin Diseases, Parasitic/diagnosis/drug therapy/immunology/*parasitology

Toxoplasma gondii is one of the major agents of infectious abortions and due to its worldwide distribution can threat healthy pregnant women who had no previous exposure to this parasite. The present study was designed to investigate the contribution of T. gondii to spontaneous abortions in Zanjan, Northwest of Iran, using ELISA method. Blood Samples were collected from 264 mothers referred to the provincial hospitals of Zanjan due to spontaneous abortion. The sera were isolated and subjected to evaluate the anti-Toxoplasma IgG, IgM and IgA antibodies. The results showed IgG positive (IgG+) in 99 cases (37.5%). A total of 68 women (25.8%) showed seroconversion with IgM or IgA or both IgM and IgA. They included: IgM+ in 21 (8.0%), IgA+ in 23 (8.7%) and both IgM+ and IgA+ in 24 (9.1%) subjects. In 23 cases, positive titers of IgM and IgG were accompanied. In general, the analysis of anti-Toxoplasma antibody patterns, showed that about 17% of the spontaneous abortions were associated with serological patterns of acute infection. According to these findings, a considerable proportion of spontaneous abortions can be attributed to T. gondii in the study area.
Abortion, Spontaneous/immunology/*parasitology ; Antibodies, Protozoan/*blood ; Cross-Sectional Studies ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin A/blood ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Iran/epidemiology ; Mothers ; Pregnancy ; Pregnancy Complications, Parasitic/*immunology/parasitology ; Toxoplasma/*immunology ; Toxoplasmosis, Congenital/*immunology/parasitology

Mucosal mast cell-derived chondroitin sulphates (sulphated proteoglycans) were assayed in gut washings and homogenate of FcRgamma-knockout (KO) and wild-type (WT) C57BL/6 mice challenged with Strongyloides venezuelensis in order to assess their possible role in secondary immunity against enteric nematodes. Groups of immune KO and WT mice were challenged by oral gavage with 300 infective larvae (L3). Establishment of infection was assessed by daily faecal analysis to determine the number of eggs per gram of faeces (EPG) and by adult worm recovery on days 5 and 13 post challenge. Mucosal mast cell (MMC) counts were done on days 5 and 13 post challenge while MMC-derived chondroitin sulphates in gut washings (days 1 and 5) and homogenate (day 8) were assayed by high performance liquid chromatography (HPLC). Results showed that patent infection occurred in challenged KO but not WT mice despite significantly higher mastocytosis in jejunal sections of KO than WT mice (p<0.001). Similarly but against prediction, significantly higher concentration of MMC-derived chondroitin sulphates was observed in gut homogenate of KO than WT mice (p<0.05). In contrast, significantly higher concentration of chondroitin sulphates was observed in gut washings of WT than KO mice (p<0.05). These results suggest that MMC in KO mice failed to release sufficient amount of sulphated proteoglycans into the gut lumen as did the WT mice, which may have been part of the hostile environment that prevented the establishment in and eventual expulsion of adult S. venezuelensis from the gut of WT mice following challenge.
Animals ; Cell Count/veterinary ; Chondroitin Sulfates/*immunology/metabolism ; Chymases ; Feces/parasitology ; Intestinal Diseases, Parasitic/immunology/*veterinary ; Intestinal Mucosa/cytology/immunology/parasitology ; Jejunum/cytology/immunology/parasitology ; Male ; Mast Cells/immunology/metabolism/*parasitology ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Parasite Egg Count/veterinary ; Receptors, IgG/*immunology ; Serine Endopeptidases/blood/immunology ; Specific Pathogen-Free Organisms ; Strongyloides/*immunology ; Strongyloidiasis/immunology/parasitology/*veterinary

PURPOSE: Since few reports had been published on the prevalence of toxocariasis in ankylosing spondylitis (AS) patients with acute non-granulomatous anterior uveitis (ANGAU), the aim of this work was to determine the presence of antibodies against Toxocara canis in AS patients with ANGAU. METHODS: Thirty-six patients (14 female and 22 male) with AS were enrolled in the study. The history of ANGAU was accepted only if diagnosed by an ophthalmologist. The detection of IgG antibodies to T. canis was determined by enzyme-linked immunosorbent assay. In addition, antibodies to Ascaris lumbricoides were also tested to verify non-specific reactions. RESULTS: The prevalence of ANGAU in the AS patients was 58% (21 / 36), and 38% (8 / 21) of the patients with ANGAU were positive for antibodies to Toxocara, while 7% (1 / 15) of AS patients without ANGAU were positive for T. canis (p = 0.038, two tails; mid-p exact). No antibodies were detected to A. lumbricoides antigens in the serum samples of patients with AS. CONCLUSIONS: These data suggest that the seroprevalence of antibodies to T. canis is high in Mexican patients with AS-associated uveitis, suggesting a chronic asymptomatic toxocariosis, which could be associated with the pathogenesis of ANGAU; however, further larger-scale studies are needed to confirm this observation.
Acute Disease ; Adult ; Aged ; Animals ; Antibodies, Anti-Idiotypic/*isolation & purification ; Enzyme-Linked Immunosorbent Assay ; Eye Infections, Parasitic/complications/*immunology/parasitology ; Female ; Humans ; Immunoglobulin G/*immunology ; Male ; Middle Aged ; Seroepidemiologic Studies ; Spondylitis, Ankylosing/*complications/immunology/parasitology ; Toxocara canis/*immunology/isolation & purification ; Toxocariasis/complications/*immunology/parasitology ; Uveitis, Anterior/complications/*immunology/parasitology ; Young Adult

Intestinal parasitic infections are one of the major causes of diarrhea in human immunodeficiency virus (HIV) seropositive individuals. Antiretroviral therapy has markedly reduced the incidence of many opportunistic infections, but parasite-related diarrhea still remains frequent and often underestimated especially in developing countries. The present hospital-based study was conducted to determine the spectrum of intestinal parasitosis in adult HIV/AIDS (acquired immunodeficiency syndrome) patients with or without diarrhea with the levels of CD4+ T-cell counts. A total of 400 individuals were enrolled and were screened for intestinal parasitosis. Of these study population, 200 were HIV seropositives, and the remaining 200 were HIV uninfected individuals with or without diarrhea. Intestinal parasites were identified by using microscopy as well as PCR assay. A total of 130 (32.5%) out of 400 patients were positive for any kinds of intestinal parasites. The cumulative number of parasite positive patients was 152 due to multiple infections. A significant association of Cryptosporidium (P<0.001) was detected among individuals with CD4+ T-cell counts less than 200 cells/microl.
AIDS-Related Opportunistic Infections/etiology/*immunology/parasitology ; Adult ; Animals ; Anti-HIV Agents/*therapeutic use ; CD4 Lymphocyte Count ; Diarrhea/etiology/*immunology/parasitology ; Female ; HIV Infections/complications/*drug therapy ; Humans ; Intestinal Diseases, Parasitic/etiology/*immunology/parasitology ; Male ; Middle Aged ; Parasites/classification/genetics/*isolation & purification ; Young Adult

PURPOSE: This study evaluated the prevalence of ocular toxocariasis (OT) in patients with uveitis of unknown etiology who visited a tertiary hospital in South Korea and assessed the success of serum anti-Toxocara immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) as a diagnostic test for OT. METHODS: The records of consecutive patients with intraocular inflammation of unknown etiology were reviewed. All participants underwent clinical and laboratory investigations, including ELISA for serum anti-Toxocara IgG. OT was diagnosed based on typical clinical findings. Clinical characteristics, seropositivity, and IgG titers were compared between patients diagnosed with OT and non-OT uveitis. The seropositivity and the diagnostic value of anti-Toxocara IgG was investigated among patients with different types of uveitis. RESULTS: Of 238 patients with uveitis of unknown etiology, 71 (29.8%) were diagnosed with OT, and 80 (33.6%) had positive ELISA results for serum anti-Toxocara IgG. The sensitivity and specificity of the ELISA test were 91.5% (65 / 71) and 91.0% (152 / 167), respectively. The positive predictive value of the serum anti-Toxocara IgG assay was 81.3%. Among patients with anterior, intermediate, posterior, and panuveitis, the prevalence rates of OT were 8.3%, 47.1%, 44.8%, and 7.1%, respectively; the seropositivity percentages were 18.1%, 47.1%, 43.7%, and 17.9%; and the positive predictive values were 38.5%, 95.8%, 92.1%, and 40.0%. The serum anti-Toxocara IgG titer also significantly decreased following albendazole treatment. CONCLUSIONS: OT is a common cause of intraocular inflammation in the tertiary hospital setting. Considering that OT is more prevalent in intermediate and posterior uveitis, and that the positive predictive value of the anti-Toxocara IgG assay is high, a routine test for anti-Toxocara IgG might be necessary for Korean patients with intermediate and posterior uveitis.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Antibodies, Anti-Idiotypic/*blood ; Aqueous Humor/parasitology ; Child ; Enzyme-Linked Immunosorbent Assay ; Eye Infections, Parasitic/*diagnosis/epidemiology/parasitology ; Female ; Follow-Up Studies ; Humans ; Immunoglobulin G/blood/*immunology ; Incidence ; Male ; Middle Aged ; Republic of Korea/epidemiology ; Retrospective Studies ; *Tertiary Care Centers ; Toxocara canis/*immunology/isolation & purification ; Toxocariasis ; Uveitis/*diagnosis/epidemiology/parasitology ; Young Adult

Ocular toxocariasis named also ocular larva migrans is caused by larvae of the roundworm Toxocara spp. The purpose of this study was to find out the seroprevalence of Toxocara antibodies in patients suspected of ocular toxocariasis. Between January 2001 and December 2003, sera from 239 ocular patients, aged 3 to 80 years, were examined by ELISA and confirmed by Western blot test. Out of the 239 patients, 172 (72%) were seronegative and 67 (28%) were Toxocara seropositive; 95% CI (22-34%). The median age of Toxocara seropositive patients was 37.6 years. There was no significant difference in the number of Toxocara positive sera between the younger age group (< or =14 years) and the older age group (> 14 years), p > 0.05. A high rate of Toxocara seropositivity in ocular patients should alert the ophthalmologists in Slovenia to include toxocariasis in the differential diagnosis of eye diseases more frequently.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Antibodies, Helminth/*blood ; Blotting, Western ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay/methods ; Eye Infections, Parasitic/*epidemiology ; Female ; Humans ; Larva Migrans, Visceral/epidemiology ; Male ; Middle Aged ; Seroepidemiologic Studies ; Slovenia/epidemiology ; Toxocara/*immunology ; Toxocariasis/*epidemiology/immunology