Cestode infections in Poland in 1999

In 1999, 437 intestinal cestode cases were registered in Poland. Among them 369 were caused by Taenia saginata, 7 by T. solium, 35 by Taenia sp., 3 by Hymenolepis nana and 2 by Diphyllobothrium latum and 39 cases of echinococcosis were also registered. The obtained results confirmed the decreasing frequency of infection with intestinal cestodes in Poland.     

Serodiagnosis of human cysticercosis using a chromatofocused antigenic preparation of Taenia solium cysticerci in an enzyme-linked immunosorbent assay (ELISA)

Crude preparations of Taenia solium cysticerci were partially purified by a chromatofocusing procedure to obtain antigenic fractions that were shown to be active in the enzyme-linked immunosorbent assay (ELISA) with known positive cysticercosis sera. Evaluation of this antigen in the ELISA serodiagnosis of human cysticercus infection showed an 80% detection of clinically typical cysticercosis patients from West New Guinea, and gave no false positive results in healthy control subjects from either Papua New Guinea or the USA. Cross-reactivity to sera from a panel of subjects with a variety of other parasitic infections was limited to convalescent sera from individuals with echinococcosis. Seroepidemiological screening of three selected tropical populations verified the presence of human cysticercus infection on Bali (Indonesia) and its absence on Guam (in the Mariana Islands) and on Mota Lava (in the Banks Islands of Vanuatu). The purified cysticercus antigen was more sensitive and more specific than crude cysticercus or whole worm preparations for the serodiagnosis of human cysticercosis.     

Cestode infections in Poland in 2002

In 2002, 264 intestinal cestode infections were registered in Poland. Among them 193 were caused by Taenia saginata, 3 by T. solium, 53 by Taenia sp., 1 by Hymenolepis nana, 1 by Diphyllobothrium latum, 1 by Hymenolepis diminuta. Moreover, 40 cases of cystic echinococcosis were also registered. The obtained results confirmed decreasing frequency of intestinal cestodoses in Poland.     

Cestode infections in animals: immunological diagnosis and vaccination

Cestode infections in animals are important because several species are zoonotic, causing cysticercosis and hydatidosis in man, and because of the economic losses incurred due to infections in livestock. Information on immunological diagnosis of and vaccination against cestode infection is restricted almost exclusively to the taeniid cestodes in which two groups of mammalian hosts are concerned: the intermediate host infected with the larval parasite and the definitive host infected with the adult tapeworm parasite. Research towards developing serological tests for the diagnosis of larval cestode infection in animals has been largely unsuccessful. Substantial problems remain, due to the frequent existence of multiple infections with different taeniid species and antigenic crossreactivity between these related parasites, and the low level of specific antibody response to infection. Problems with poor specificity and sensitivity of traditional serological tests for cysticercosis and hydatidosis have prevented the development of any practical test for ante-mortem diagnosis of infection. A recent new approach to the diagnosis of Taenia saginata infection by detecting circulating parasite antigen offers some prospect for the development of a practical diagnostic test for cysticercosis in cattle. The effectiveness of the arecoline purge for detection of Echinococcus granulosus in dogs has been reduced by the widespread availability of praziquantel. A serological method for diagnosis of E. granulosus in dogs has been developed which offers equivalent or superior diagnostic sensitivity compared with arecoline purge. This test should provide a valuable tool in hydatid control campaigns for the diagnosis of existing or recent past infections in dogs. Substantial progress has been made towards developing a practical vaccine for the prevention of T. ovis infection in sheep. An antigen derived from the parasite egg has been identified and produced in Escherichia coli using recombinant DNA techniques. The vaccine, which protects sheep against challenge infection with T. ovis, is the first highly effective defined antigen vaccine against any parasite infection of man or animals. Commercial development of this vaccine is in progress. The success achieved with the T. ovis vaccine augurs well for the rapid development of other recombinant vaccines against cysticercosis caused by other taeniid species and against hydatidosis in animals.     

Cestode infections in 1998

In 1998, 603 intestinal cestode cases were registered in Poland. Among them 516 were caused by T. saginata, 5 by T. solium, 59 by Taenia sp., 2 by Hymenolepis nana and 1 by D. latum. Moreover, 31 cases of larval cestode infections were also registered. Three of them were caused by larvae of T. solium and the remaining ones by E. granulosus. The obtained results confirmed the decreasing frequency of infections with intestinal cestodes in Poland.     

Cestode infections in Poland in 2000

In 2000, 439 intestinal cestode infections were registered in Poland. Among them 359 were caused by Taenia saginata, three by T. solium, 52 by Taenia sp., two by Hymenolepis nana, two by Diphyllobothrium latum, and one by Dipylidium caninum. Moreover, 29 cases of echinococcosis were also registered. The obtained results confirmed the low frequency of intestinal cestodoses in Poland.     

Antibody to the nonstructural protein NS1 of Japanese encephalitis virus: potential application of mAb-based indirect ELISA to differentiate infection from vaccination

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination.     

Intestinal parasite infections in a semiarid area of Northeast Brazil: preliminary findings differ from expected prevalence rates

We report on intestinal parasite infection prevalence in a population sample from S o Raimundo Nonato, Southeast Piau State, Brazil, aimed at comparison with previous studies on Trichuris trichiura and Ascaris lumbricoides infection. A total of 265 stool specimens were collected and examined by spontaneous sedimentation. Approximately 57% of specimens were infected with at least one parasite species. Entamoeba coli (35.8%), Endolimax nana (13.6%), Hymenolepis nana (9.4%), and hookworm (9.4%) were the most frequently observed parasites. Two cases of roundworm infection were detected, probably acquired outside the region. T. trichiura eggs were not found. Interestingly, neither A. lumbricoides nor T. trichiura has been found in local prehistoric human coprolites. Nevertheless, hookworm infection has been present in the region for at least 7,000 years.     

Neurocysticercosis and epilepsy in Cameroon

During January 2002 the frequency of Taenia solium cysticercosis was studied in a series of 504 epileptic patients from 3 rural localities in the West and North-West provinces of Cameroon using an enzyme-linked immunosorbent assay for both circulating antigen (Ag-ELISA) and antibody (Ag-ELISA) detection. Taenia solium antigens were detected in the sera of 1.2% of the patients whereas specific antibodies against the parasite were present in 44.6% of the patients. Significantly less seropositive results in Ab-ELISA were recorded in Batibo than in Bandjoun and Bamendjou, whereas a borderline significant difference was recorded with increasing age. Furthermore, 56.2% of patients with late-onset epilepsy showed antibodies against cysticercosis. Taenia solium cysticercosis appears to be an important cause of epilepsy in Cameroon.     

An enzyme-linked immunosorbent assay for diagnostic detection of Taenia saginata copro-antigens in humans.

An immunodiagnostic sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of soluble Taenia saginata antigens in stool samples (copro-antigens) of infected humans, using affinity-purified polyclonal antibodies obtained from rabbits hyperimmunized with excretory/secretory antigens derived from T. saginata maintained in vitro. Investigation of operating characteristics showed very low cross-reactivity with crude antigens from helminths other than Taenia, including Dipylidium caninum and Diphyllobothrium latum. The specificity of the assay was 95% when testing stool samples from 100 persons who were either infected with Ascaris lumbricoides, Trichuris trichiura, hookworms, Enterobius vermicularis or Hymenolepis nana, or who had no intestinal helminthosis detected. Analysis of diagnostic sensitivity demonstrated that in 85% of 34 samples from 23 untreated persons with intestinal T. saginata infection (selected by previous proglottid and/or egg detection) copro-antigens were detected by the T. saginata ELISA. In the same samples, Taenia eggs were detected in 62%. Only 41% of the samples reacted positively in a heterologous T. hydatigena ELISA. Post-treatment control revealed a high concentration of T. saginata copro-antigens for 1-4 d after administration of niclosamide or praziquantel, and negative values 9-17 d after treatment. The Taenia copro-antigens remained detectable by ELISA even after storage of untreated faeces at 25 degrees C for at least 5 d.     

Enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against foot-and-mouth disease virus. III. Evaluation of antibodies after infection and vaccination

Investigations using a liquid-phase blocking sandwich enzyme-linked immunosorbent assay (ELISA) for the measurement of antibodies against foot-and-mouth disease virus (FMDV) in sera from sheep and from cattle are reported, and results compared with those obtained by virus neutralization (VN) tests. Serum antibody titres in sheep after primary vaccination and in cattle challenged with a natural aerosol after vaccination were similar by ELISA and VN. However, the antibody levels detected in sera of cattle during early infection and of vaccinated cattle after intradermolingual challenge were clearly greater by ELISA than by VN. The ELISA titres in cattle sera following synthetic peptide vaccination indicated some relationship to protection and were clearly different from those recorded by VN. On the other hand, the antibody levels following conventional vaccination showed that ELISA and VN titres in cattle sera were related to protection. Although there was a good agreement between the ELISA antibody titre and protection for the four vaccines used, by VN the titre which afforded protection varied depending on the vaccine used. The ELISA was considered therefore to be more reliable than the VN and may prove useful for evaluating the immunological response of animals following infection and following vaccination.     

Vaccination with Setaria cervi 175 kDa collagenase induces high level of protection against Brugia malayi infection in jirds

A zinc containing metalloprotease, 175 kDa collagenase, purified from adult female Setaria cervi showed strong cross-reactivity with sera from putatively immune (PI) individuals (unpublished observation) and induced cytotoxicity to B. malayi L3 larvae and microfilariae by ADCC mechanism [Srivastava Y, Bhandari YP, Reddy MVR, Harinath BC, Rathaur S. An adult 175 kDa collagenase antigen of Setaria cervi in immunoprophylaxis against Brugia malayi. J Helminth 2004;78:347-52]. These preliminary observations suggested the immunoprotective nature of collagenase. To confirm the vaccine potential of this protease, a vaccine trial was conducted in jirds (Meriones unguiculatus) against human filarial parasite B. malayi. The vaccination resulted into a mean protection level of 75.86% and produced high level of protease neutralizing antibodies. Cytokine analysis in immune jirds sera suggested a mixed Th1/Th2 type cellular immune response whereas ELISA, immunoblotting and enzyme antibody inhibition assay revealed the presence of specific anti-collagenase antibodies. Taken together, all these results suggest that S. cervi 175 kDa collagenase could form the basis of an effective molecular vaccine against human lymphatic filariasis.     

检测抗-HCV IgG κ/λ轻链比值及其临床意义

目的 探讨丙型肝炎病毒(HCV)感染者保护性免疫缺陷的原因。方法 根据HCV C区和NS4区基因序列设计并人工合成3条合成肽。采用抗原捕捉酶联免疫吸附试验检测HCV感染者血清中抗-HCV IgG抗体轻链κ／λ比值。结果 抗-HCV SP42，CP10和CP9抗体轻链的表达呈明显的偏斜；84例抗-HCV阳性者中82例(97．62％)抗-HCV IgG抗体轻链κ／λ比值偏离。所有病例追踪观察一年(其中11例抗-HCV阳性者随访二年)，发现抗-HCV抗体κ／λ比值恒定不变。结论 HCV感染者抗-HCV抗体的产生不均匀性并呈稳定的克隆性。B细胞克隆优势化可能是HCV感染后机体保护性免疫缺陷的原因之一。     

Evidence for high seroprevalence of Taenia solium cysticercosis in individuals from three rural communities in Venezuela

A serological study was undertaken in 1998 to evaluate levels of Taenia solium cysticercosis in 3 rural Venezuelan communities. Infection with viable metacestodes was diagnosed with a trapping enzyme-linked immunosorbent assay (ELISA) that detects a secreted product of viable parasites. Anti-metacestode antibodies were assayed by ELISA using T. solium vesicular fluid as antigen. A total of 1254 sera was collected from 3 communities (Canoabo, Sanare, and Rio Tocuyo) where previous studies had suggested the presence of T. solium. Our results demonstrate an unusually high seroprevalence of cysticercosis, indicating an attendant risk of transmitting the disease to other areas. The seroprevalence of infection with viable cysts, as indicated by detection of circulating parasite antigen, was 9.1% in Canoabo, 6.1% in Sanare, and 5.7% in Rio Tocuyo. The corresponding frequency of antibodies to T. solium cyst antigens was 36.5% in Canoabo, 36.5% in Sanare, and 4% in Rio Tocuyo. As these communities are probably representative of many others in Venezuela, T. solium cysticercosis may be a significant public health problem and more work is certainly indicated. An important finding was that local knowledge of the disease and its transmission do not necessarily guarantee diminished disease prevalence, indicating a lack of appropriate vigilance towards disease control.     

Serological markers of Chlamydia pneumoniae,cytomegalovirus and Helicobacter pylori infection in diabetic and non-diabetic patients with unstable angina pectoris

The possible role of inflammation in coronary artery disease (CAD) is being recognised, while markers of inflammation (e.g., CRP) and infection with Chlamydia pneumoniae (C. pneumoniae), cytomegalovirus (CMV) and Helicobacter pylori (H. pylori) have been proposed as risk factors for CAD. However, these associations require further evaluation. It is a known fact that diabetic patients suffer from impaired immune response to some pathogens and a high incidence of atherosclerosis. In this case-control study we investigated serological markers of infection with C. pneumoniae, CMV, and H. pylori in a group of 140 patients with unstable angina pectoris (UA), 52 of them having type 2 diabetes mellitus, and in a matched control group. Anamnestic (IgG) and acute infection (IgA) antibodies against the above agents were tested using ELISA or indirect immunofluorescence tests. In patients with UA we found a significantly higher seroprevalence and titres of IgG antibodies against C. pneumoniae (p = 0.04) and increased titres of IgG antibodies against CMV (p = 0.007). No differences were found in IgA antibody response to these pathogens. Antibody response to H. pylori was similar in both groups tested. In diabetic patients with UA, the frequency of group-common IgG antibodies against C. pneumoniae was higher than in the non-diabetic UA patients. The other serological markers studied were comparable in the patients with or without diabetes mellitus. Our findings confirmed association of C. pneumoniae and CMV with cardiovascular heart disease. Moreover, diabetes mellitus may predispose the patients to C. pneumoniae infection. However, serological markers observed do not indicate that destabilisation of angina pectoris is associated with acute C. pneumoniae or CMV infection. No relationship was found between UA and H. pylori infection.     

幽门螺杆菌全菌抗原与尿素酶纯化抗原ELISA检测在人群血清学诊断中的应用

用纯化的Ｈｐ抗原对６７６例各型胃病患者进行了血清抗幽门螺杆菌尿素酶抗体的检测。实验证明其特异性为９６％，敏感性为９８％。血清学ＥＬＩＳＡ检测法，尤其适宜于流行病学调查，还可用于药物治疗效果的观察和筛选非溃疡性消化不良。     

Dengue virus infections in Nigeria: a survey for antibodies in monkeys and humans.

A retrospective serological survey for dengue immunity was conducted in Nigeria to determine the prevalence of infection in man and non-human primates. Preliminary haemagglutination-inhibition (HI) tests revealed that 63% of persons tested had HI antibodies against one or more of the following flaviviruses: dengue type 1, yellow fever, West Nile and Wesselsbron. Parallel HI and neutralization (N) tests on 179 human sera showed that six of 20 sera (30%) negative for flavivirus HI antibody contained dengue N antibody. This finding emphasized the advantage of the N test over HI in screening for dengue virus immunity. Neutralization tests performed on 1,816 human sera from different geographical locations in Nigeria showed that 45% of Nigerians were immune to dengue type 2 virus. The percentage of immunity in adults aged 20 years and older (51%) was significantly higher than in children (37%) (P less than 0-01). In all four ecological zones sampled, the highest percentage of dengue N antibody was observed in the derived Savannah zone (63%) followed by the rain forest zone (42%). The Southern Guinea savannah and plateau zones had lower percentages of dengue-immune persons. There was a higher prevalence of antibodies in urban (48%) than in rural communities (37%). Tests on dengue-immune sera showed that 35% of such sera contained N antibodies to dengue only or to dengue and one other virus. Therefore, dengue immunity cannot be explained by heterologous cross reactions within the flavivirus group. In addition, evidence of dengue infection was found in monkeys and galagos. 48% of monkeys and 25% of galagos contained dengue N antibody. The presence of specific dengue N antibodies in a few sera suggests that the occurrence of a forest cycle of dengue is possible in Nigeria.     

Albendazole: placebo-controlled study in 870 patients with intestinal helminthiasis

A total of 870 patients, both males and females, from 3 to 79 years old, received either albendazole or a placebo for the treatment of nematode and cestode infections. Each patient was interviewed and underwent a complete physical examination on the initial visit. In addition, complete blood count, clinical blood chemistry values and routine urinalysis were performed before and at least 24 hours after the last treatment. Stool examinations were performed before, 7 and 21 days after treatment. Direct examination, an egg count using the Kato technique and faecal concentration were carried out for each patient. In ancylostomiasis and strongyloidiasis, faeces were cultured by the Harada-Mori technique. Albendazole, as a single 400 mg oral dose, was highly effective against Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura; efficacy against Strongyloides stercoralis was observed after three consecutive days of treatment at the same daily dose level. Efficacy against Hymenolepis nana was fair. Based on both clinical signs and biological values, albendazole did not produce any significant side effects.     

Parvovirus B19 antibodies in the blood in 17-34-year-old women

In order to assess the proportion of women in fertile age who lack antibodies against parvovirus B19 the authors assessed in 2 groups of sera (63 and 40 sera) taken from 17-34-year-old women antibodies against this virus by the ELISA method (Seiken). Virus-specific antibodies, class IgG were detected only in 67% of the examined subjects which indicates that in one third of the women there is a risk of transplacental infection of the foetus in case of infection with the parvovirus B19 during pregnancy.     

Antibody response in children to antigen sites on human PIV-3 HN: correlation with known epitopes mapped by monoclonal antibodies.

The antibody response in children to known epitopes on the HN of human parainfluenza virus type 3 was investigated. Children's sera with Haemagglutination-Inhibition titres between 1/480 to 1/1280 were used. When tested by ELISA, this high-titre serum from each of five children blocked 7 of 17 specific anti-HN murine monoclonal antibodies by greater than 75% at 1 micrograms well-1 of antigen. However, four monoclonal antibodies were blocked less than or equal to 30%, while six were partially blocked between 50% and 75%. Antigen concentrations of 0.5, 1.5 and 2.0 micrograms well-1 did not substantially change this pattern. Comparison of our results with published antigenic maps indicated that antigenic site A on the HN protein was the site with the most significant antibody representation in the children's sera. These findings suggest that antigenic maps deduced using monoclonal antibodies need to be carefully interpreted before they are used in vaccine development. Murine monoclonal antibodies may not fully represent either qualitatively or quantitatively important antibody components of the human or murine immune response to human PIV-3 HN.