Cantonensis Infection Research Articles

Induction of cerebrospinal fluid eosinophilia in rats by the intraventricular injection of Angiostrongylus cantonensis antigen

Resistance to Angiostrongylus cantonensis is contingent upon the generation of an eosinophilic response in the CSF of infected hosts. We have studied the parameters required for the generation of this CSF eosinophilia in normally permissive rats. We initially induced a marked peripheral eosinophilia in rats by infection with either Mesocestoides corti or Angiostrongylus cantonensis or the surgical transfer of A. cantonensis young adult worms (YA) into their pulmonary arteries. Next, we injected various antigens into the ventricles of these rats. A. cantonensis-preinfected rats demonstrated significant CSF eosinophilia following injection of A. cantonensis egg antigen, 1st-stage larval (L 1) antigen, or M. corti antigen, but not following YA antigen inoculation. A. cantonensis egg and M. corti antigens were potent chemoattractants for eosinophils in an in vitro chemotaxis assay. These data indicate that peripheral eosinophilia, meningeal stimulation by A. cantonensis infection and the presence of potent chemoattractants, e.g., egg and L 1 antigens are prerequisites for CSF eosinophil accumulation in permissive rat hosts.

Angiostrongylus cantonensisInfection from Eating Raw Snails

To the Editor: Eosinophilic meningitis caused by Angiostrongylus cantonensis is widespread in the Pacific basin and has been reported in Cuba, Reunion, and the Ivory Coast.1 To our knowledge, however, no human infection with A. cantonensis has been reported in North America to date. We report a case of autochthonous A. cantonensis infection in a child in New Orleans. An 11-year-old boy presented to Children's Hospital in New Orleans on June 24, 1993, with myalgia (which he had had for seven days), headache, low-grade fever, vomiting (for six days), and a stiff neck (for five days). He had always lived . . .

The role of eosinophils in Angiostrongylus cantonensis infection.

Angiostrongylus cantonensis is the causative agent of human eosinophilic meningoencephalitis in the Pacific Islands and Southeast Asia. Prominent eosinophilia in the cerebrospinal fluid (CSF) of the patients has been used as one of the diagnostic criteria for the disease but the role(s) of the CSF eosinophils has remained to be elucidated. In this article, Kentaro Yoshimura, Hiroko Sugaya and Kazuto Ishido discuss the involvement of CSF eosinophils in the killing of intracranial worms and the damage of the central nervous system of the hosts, and consider why eosinophils in A. cantonensis infection play a more important role in nonpermissive hosts (including humans) than in the permissive rat host.

The effect of cyclosporin A on Angiostrongylus cantonensis infection and eosinophilia in mice

Male BALB/c mice were infected with Angiostrongylus cantonensis and at various times p.i. treated with cyclosporin A (CsA) either for 5 days continuously or intermittently, or for 12–16 days on alternate days. They were monitored for peripheral blood eosinophilia and at necropsy examined for CSF and bone marrow eosinophilia, and worm recovery. CsA treatment provoked a transient inhibition of peripheral blood eosinophilia in all groups examined, followed by rebounding eosinophilia. There was no significant difference in bone marrow and CSF eosinophilia between CsA- and vehicle-treated groups. Mice treated with CsA on alternate days yielded lower intracranial worm recovery with small-sized worms at days 7, 21 and 30 p.i. than vehicle-treated groups did. No significant reduction in worm recovery was noted in mice treated for 5 days either continuously or intermittently, although worms, especially female ones, harvested from groups treated with CsA from days — 1 to 3 or from days 13 to 17 were significantly smaller than those from vehicle-treated groups. CsA-treatment suppressed blastogenic responses of spleen cells against Con A or worm antigen at days 7 and 21 p.i. In vitro treatment of the 3rd stage larvae with CsA did not adversely influence survival of A. cantonensis in mice. These data indicate that CsA exerts antiparasitic effects against A. cantonensis in mice.

The influence of Mesocestoides corti on subsequent Angiostrongylus cantonensis infections in mice

The influence of Mesocestoides corti on subsequent Angiostrongylus cantonensis infection in mice (C57BL/6 and BALB/c) was assessed. Both strains of mice infected with M. corti demonstrated a peak blood eosinophilia at around 3 weeks post-infection (p.i.). C57BL/6 and BALB/c mice primarily infected with M. corti were given A. cantonensis infection 18 days later, but pre-existing M. corti infection did not affect the recovery of intracranial worms of A. cantonensis at day 21 p.i. BALB/c mice with mixed parasite infections showed low morbidity and mortality as compared with mice singly infected with A. cantonensis and some mice demonstrated a pulmonary migration of intracranial worms. In C57BL/6 mice, intracranial worms were killed and thus all mice survived. C57BL/6 mice with mixed parasite infections failed to resist A. cantonensis reinfection. The blastogenic responses of spleen cells against A. cantonensis antigen were lower in BALB/c than in C57BL/6 mice and mixed parasite infections also resulted in less blastogenic responses against both concanavalin A and A. cantonensis antigen than monoinfection. The recovery of M. corti biomass was significantly higher in mice with mixed parasite infections than mice with monoinfection with M. corti. These data suggest a distinct difference in response to A. cantonensis infection between C57BL/6 and BALB/c mice, and the induction of immunosuppression in both mouse strains following M. corti infection. Blood eosinophilia provoked by M. corti infection is not directly associated with the killing of worms in subsequent A. cantonensis infection.

Acquired immunity in rats against Angiostrongylus cantonensis infection

Wang L.-C., Chao D. and Chen E.-R. 1989. Acquired immunity in rats against Angiostrongylus cantonensis infection. International Journal for Parasitology 19: 617–620. Acquired immunity against Angiostrongylus cantonensis was induced by immunizing rats with somatic antigens from fifth-stage larvae and adult worms and live third-stage larvae. Rats immunized twice had significantly fewer worms than rats immunized three times. Fewer worms were recovered from rats immunized with 200 live third-stage larvae than from any other groups. Rats immunized with somatic antigens had higher enzyme-linked immunosorbent assay (ELISA) antibody levels than rats immunized with live larvae. Rats immunized with live third-stage larvae of Angiostrongylus cantonensis were more strongly protected against challenge infections (62–92%) than rats immunized with antigens extracted from fifth-stage larvae (0–30%) and adult worms (11–24%).

Total and specific IgE in serum and cerebrospinal fluid of rats and guinea pigs infected with Angiostrongylus cantonensis.

The total and specific IgE response to Angiostrongylus cantonensis infection was evaluated according to host permissiveness. Total IgE levels measured by a double antibody radioimmunoassay (RIA) increased slowly in the permissive host (the rat), reaching a maximum between 4 and 8 weeks after infection. This maximum was earlier but significantly lower in the non-permissive host (the guinea pig). IgE antibodies specific for adult worms or L1 or L3 larvae of A. cantonensis were measured by a radioallergosorbent test (RAST). In the case of adult worms and L1 antigens, specific IgE antibody levels showed large variations in relation to the duration of infection in rats. In contrast to total IgE levels, the specific IgE response to L3 larvae was lower in rats than in guinea pigs in both the serum and cerebrospinal fluid (CSF). These results suggest variations in the total vs specific IgE response according to host permissiveness or non-permissiveness to A. cantonensis infection. These results are discussed in the context of the possible participation of IgE antibodies in immune defence.

Effect of UV-irradiation, spleen cells and MLN cells on protective immunity against Angiostrongylus cantonensis infection in mice.

The UV-irradiated larvae of Angiostrongylus cantonensis were used for inducing immunity in mice. A single oral dose of 100 infective UV-irradiated larvae exposed for 5 min or 15 min induced 91% and 97% protection against subsequent infection. Adoptive protection against A. cantonensis could also be transferred by spleen and mesenteric lymph node cells obtained from vaccinated mice.

Polyclonal B cell activation during the course of Angiostrongylus cantonensis infection

The numbers of IgM antibody forming cells against various heterologous antigens: SRBC, HRBC, TNP and FITC, were found to be elevated in the spleens of rats after infection with Angiostrongylus cantonensis. In these rats, the number of splenic B cells and total IgG and IgM levels in serum also increased spontaneously about 2- to 3-fold of uninfected rats during the course of the infection These results suggested that A. cantonensis infection may activate B cells polyclonally in the spleens of the infected rats. While, it was clearly observed that the antibody response to SRBC injection was significantly depressed in these rats, compared to those of uninfected rats. The relation between the polyclonal B cell activation and the immunodepression was discussed.

The presence of Angiostrongylus cantonensis in Viti Levu, Fiji.

Wild rats and molluscs were examined for Angiostrongylus cantonensis infection on Viti Levu, Fiji. A. cantonensis were recovered from 29.6% (16/54) of Rattus rattus and 59.5% (25/42) of R. exulans. A. cantonensis-like larval nematodes were found in all of four slugs, Laevicaulis alte, and ten of 20 unidentified land snails. The larvae developed to adult A. cantonensis in the pulmonary arteries of laboratory rats 40 to 42 days after ingestion. This is the first record of A. cantonensis in Fiji.

Peripheral blood white cell responses during Angiostrongylus cantonensis infection in rats

Yono W. K. and Dobson C. 1984. Peripheral blood white cell responses during Angiostrongylus cantonensis infections in rats. Interntional Journal for Parasitology 14: 207–211. Changes in white blood cell (WBC) populations and their proliferative responses to phytohaemagglutinin (PHA) and parasite antigens in vitro were studied in rats given one to three concurrent infections with Angiostrongylus cantonensis. WBC counts were elevated following infection; these changes were augmented following each successive reinfection. The WBC response could be partitioned into variations in the numbers of four major cell types. There was a loss of lymphocytes from the circulation after infection or reinfection followed by an increase in circulating lymphocytes when the parasite migrated to the lungs and matured. An eosinophilia was observed in all rats immediately after infection which was enhanced successively after each reinfection. The monocyte populations increased in a similar, but less obvious manner, to the eosinophil leucocytes. Neutrophil leucocytes increased after infection, but the numbers declined after reinfection. All rats given one to three infections showed a neutrophilia late in the experiment. A reversal in the neutrophil leucocyte-lymphocyte ratio was observed after each infection. A peak response in the proliferation of peripheral blood lymphocytes in vitro to PHA preceded and exceeded that stimulated by A. cantonensis antigen. These responses were interpreted as the dissemination of uncommitted thymus-dependent lymphocytes involved in the induction of antigen sensitized memory cells released following the protective immune reaction. The degree of lymphocyte responsiveness to mitogens correlated with the numbers of these cells circulating at each time interval. The relationships between in vitro lymphocyte responses and protective immunity in the rat against A. cantonensis are discussed.

Prevalence of Angiostrongylus cantonensis infection in commensal rats in Bombay.

ABSTRACTThe prevalence Angiostrongylus cantonensis, a metastrongylid lungworm of rats, was investigated in three common species of rodents in the Greater Bombay area, namely, Rattus rattus, R. norvegicus and Bandicota bengalensis. In all, 737 R. norvegicus, 100 R. rattus and 100 B. bengalensis were examined and the presence of A. cantonensis infection was noticed in R. norvegicus (1·62%). About 800 slugs (Laevicaulis alte) were examined and were found to harbour third-stage larvae of Angiostrongylus.

Antibody responses in rats infected with Angiostrongylus cantonensis and the passive transfer of protective immunity with immune serum.

Little haemagglutinating antibody was detected in the serum of rats with primary Angiostrongylus cantonensis infections until the juvenile worms left the brain and lodged in the lungs about 35 days after infection. Antibody titres reached a peak 50 days after infection and were maintained for at least a further 95 days. Increasing the infective dose of A. cantonensis larvae increased the peak antibody titres attained by the infected rats. Re-infection temporarily reduced the serum antibody titre, but later it increased and showed an anamnestic response. Reaginic antibody production was transient during primary infections; re-infection failed to stimulate further reaginic antibody production. Antiserum from immune donor rats protected recipients against A. cantonensis. The transferred immune serum suppressed anti-A. cantonensis antibody production in recipient rats.

The course of Angiostrongylus cantonensis infection in athymic nude and neonatally thymectomized mice.

BALB/c athymic nude and thymus-reconstituted nude mice and neonatally thymectomized BALB/c mice were infected with stage 3 larvae of Angiostrongylus cantonensis and the worm burdens of the mice were determined at various times after infection. When the nude and thymectomized mice were exposed to the parasite, some worms were found to migrate from the brain to lungs but died there without reaching maturity. This pulmonary arterial migration of the worms in the nude did not occur following thymic reconstitution. These data suggest that the inability of murine intracranial worms to migrate to the lungs is at least in part due to thymus-dependent mechanisms, and also that the failure of worm maturation in mouse lungs might be due to thymus-independent immune mechanisms and/or nonimmunological mechanisms.

Use of excretory and secretory products from adult female worms to immunize rats and mice against Angiostrongylus cantonensis infection.

To evaluate their protective potential, excretions and secretions of adult female Angiostrongylus cantonensis were prepared from an in vitro culture fluid and injected together with Freund's complete and incomplete adjuvants into rats and mice. Under appropriate conditions, judging from reduced mortality rates and/or prolonged survival periods, these animals were protected against a lethal challenge infection with 3rd-stage larvae. Although both 'immunized' and unimmunized mice died following such a lethal infection, the survival period for the 'immunized' group was significantly longer than that of unimmunized controls (40.8 compared with 26.7 days). On the other hand, the mortality rate of 'immunized' rats was reduced to 25% as compared with 100% in unimmunized controls. There was also evidence of adverse effects on parasite development in these 'immunized' rats. The number of young adult worms recovered from the brain 21 days after challenge infection and both the number and size of mature male and female worms in the lungs 60 days after infection were significantly reduced in the 'immunized' rats. Moreover, the reproductive activity of female worms was depressed, as evident from the output of 1st-stage larvae in the faeces and the number of eggs released during maintenance in vitro. The quantity of proteins released during in vitro maintenance of adult worms in a chemically defined serum-free medium was 0.2--0.5 micrograms/worm/day. The concentrated culture fluid contained at least 7 different antigenic components when analysed with hyperimmune rabbit antiserum to female excretions and secretions (FES) antigen. Polyacrylamide gel electrophoresis in sodium dodecylsulphate showed the presence of 3 major and at least 12 minor protein components with molecular weights varying from 24,000 to 115,000 daltons. Different lines of evidence presented in this study show immunological cross-reactivity among antigens from different developmental stages.

Changes in worm burden, haematological and serological response in rats after single and multipleAngiostrongylus cantonensis infections

Thirteen groups of rats were first sensitized with single or double doses of 5--30 third-stage larvae of Angiostrongylus cantonensis, followed by a challenge infection with 100 larvae at various periods after the primary infection. Seven other groups of rats receiving only the sensitizing infection served as the controls. In all the sensitized rats, a significantly (p less than 0.05) smaller mean number of adult worms was found established in the challenge infection as compared to the control. The frequency of the sensitizing dose and timing of the challenge infection appeared to influence the intensity of the host's response. There was no conclusive evidence to indicate that the immune response could retard the growth, development, or sex ratios of the worms established in subsequent infections. A positive haemagglutinating antibody response was first observed in some rats as early as four weeks post-infection with 100 larvae when the worms began migrating from the brain to the lungs. The antibody response and eosinophilia were most pronounced during the oviposition of the female worms and hatching of first-stage-larvae. Changes in white blood cell, lymphocyte, and neutrophil counts were also followed in some groups.

Immunodiagnosis of parasitic zoonoses: comparative efficacy of three immunofluorescence tests using antigens purified by affinity chromatography

Three immunofluorescent antibody assays were developed during this study: the direct (DFAT) and indirect (IFAT) fluorescent antibody tests using frozen worm sections, and the cyanogen bromide indirect fluorescent antibody test (CNBr-IFAT) using helminth antigens purified by affinity chromatography bound on to commercially prepared CNBr-Sepharose 4B beads. Purified antigens used in the CNBr-IFAT gave greater specificity and sensitivity than either the DFAT or IFAT. Dirofilaria immitis, Toxocara canis, Angiostrongylus cantonensis and Ascaris lumbricoides infections were studied in natural and zoonotic hosts and in rabbits immunized with antigens prepared from these parasites. In addition, a serological survey of Aboriginal Australians from Queensland was made.

Delayed hypersensitivity responses of guinea pig and rat to Angiostrongylus cantonensis infection.

Delayed hypersensitivity responses of guinea pig and rat to Angiostrongylus cantonensis infection.

Eosinophilic meningitis in Okinawa. Three suspected cases of angiostrongyliasis in man.

Three cases of eosinophilic meningitis were observed in 1969 on Okinawa, in the Ryukyu Islands between 26°04′ and 26°51½′ North latitude. Each of the patients exhibited a clinical picture similar to that seen in Angiostrongylus cantonensis infections elsewhere in the Pacific Ocean area and Southeast Asia. Infection by this metastrongylid nematode is endemic in populations of Rattus norvegicus and Rattus rattus in Okinawa and certain other islands of the southern Ryukyus. In the cases in man, there had been exposure to infection by direct contact with an intermediate host, the abundant snail Achatina fulica, in one instance by deliberate ingestion in the raw state, but other modes of transmission were not excluded. These are the first suspected cases of angiostrongyliasis in man in the Ryukyu Islands and, to our knowledge, the only such cases in the subtropics at this latitude that have been reported.

Comparative pathology in experimental infection of pigs and calves with larvae of Angiostrongylus cantonensis

Angiostrongylus cantonensis infection was produced experimentally in pigs and calves by the oral administration of third-stage larvae. Living and normal third-stage larvae, without evidence of further development, were isolated from the visceral organs of a pig at 3 days and of calves at 3, 7, 14 and 28 days after dosing. Larvae recovered 3 days after infection from the stomach of a pig, and from the lungs, peritoneal and thoracic cavities of a calf, produced cerebral infection when fed to rats. A few which appeared normal and were recovered from the lungs of calves 7 to 28 days after infection failed to produce cerebral infection when fed to rats in small numbers. It is not known to what extent these results were due to the comparatively few larvae which were fed to the rats. In pigs, larvae, in process of disintegration, were found enclosed in granulomas in the wall of the digestive tract and in mesenteric and mediastinal lymph nodes. A characteristic form of interstitial focal hepatitis also developed during the second week of infection. In calves, the larvae were found mostly in the pulmonary lymphatics and in mediastinal lymph nodes. The granulomatous reaction was delayed and several larvae, apparently morphologically intact, were found in the lungs as late as 28 days after infection. Unlike the pigs, no interstitial focal hepatitis developed in any of the calves. In one pig and in all five calves, some of the larvae migrated and developed to the fourth-stage in the central nervous system. The lesions are described.