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H Kollaritsch

Publications and source records attributed to H Kollaritsch.

At least 19 recordsLinked to original sources
PubMed2003

Antigen dependent adverse reactions and seroconversion of a tick-borne encephalitis vaccine in children.

Two randomized, double blind dose comparison studies were conducted in 595 children in Austria and Germany with an albumin-free and thiomersal-free tick-borne encephalitis (TBE) vaccine. Vaccinated subjects of an age between 6 months and 12 years randomly assigned received either the full adult dose or half the adult dose. Results from vaccinated children under 1 year of age at the time of the first vaccination (159 subjects) showed an age dependent immune response. There were significantly fewer adverse systemic events (e.g. fever reactions). In children who received only half the adult dose, while seroconversion was not significantly different (93% versus 98%) after the second vaccination, and 100% for both groups after the third vaccination. Based on these results, it is recommended to vaccinate children between the ages of 1 and 12 years with half the adult dose.

Aging↗
PubMed2003

Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data.

Previous studies have indicated that age is a risk factor for severe falciparum malaria in nonimmune patients. The objectives of this study were to reevaluate previous findings with a larger sample and to find out how strongly clinical outcomes for elderly patients differ from those for younger patients. Results of adjusted analyses indicated that the risks of death due to falciparum malaria, of experiencing cerebral or severe disease in general, and of hospitalization increased significantly with each decade of life. The case-fatality rate was almost 6 times greater among elderly patients than among younger patients, and cerebral complications occurred 3 times more often among elderly patients. Antimalarial chemoprophylaxis was significantly associated with a lower case-fatality rate and a lower frequency of cerebral complications. Women were more susceptible to cerebral complications than were men. Our study provides evidence that falciparum malaria is more serious in older patients and demonstrates that clinical surveillance networks are capable of providing quality data for investigation of rare events or diseases.

Age Factors↗
PubMed2002

Imported Falciparum malaria in Europe: sentinel surveillance data from the European network on surveillance of imported infectious diseases.

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Adolescent↗
PubMed2001

Antimalarial activity of azithromycin, artemisinin and dihydroartemisinin in fresh isolates of Plasmodium falciparum in Thailand.

Antibiotics with antimalarial activity may offer an interesting alternative for the treatment of multidrug-resistant falciparum malaria. Azithromycin, a relatively recent semisynthetic derivative of erythromycin, was tested for its in vitro activity against fresh isolates of Plasmodium falciparum. As the reportedly slow onset of action of azithromycin suggests its combination with fast-acting substances, such as artemisinin-derivatives, dihydroartemisinin (DHA) was tested parallel as a possible combination partner. The effective concentrations found for azithromycin in this study (EC(50) = 29.3 micromol/l, EC(90) = 77.1 micromol/l blood medium mixture (BMM)) are comparable to those of other antimalarials in the antibiotics class and are considerably higher than those found for mefloquine or quinine. The absence of an activity correlation between azithromycin and chloroquine, quinine and artemisinin emphasises the independence of azithromycin drug response from the sensitivity to these drugs. A weak activity correlation (rho(EC90) = 0.352; p = 0.028), which could point to a potential cross-sensitivity but is probably of little clinical importance, was found with mefloquine above the EC(50) level. Provided that further clinical trials support the combination of these drugs, DHA may offer an interesting combination partner for azithromycin owing to its rapid onset of action and the comparatively low effective concentrations (EC(50) = 1.65 nmol/l, EC(90) = 7.10 nmol/l BMM). This combination may serve as an interesting alternative for tetracycline and doxycycline, which cannot be used in pregnant women and children, and exhibit phototoxicity. Nevertheless, the relatively high cost of this combination, as well as the controversial reports of the clinical efficacy, may limit the usefulness of azithromycin in malaria therapy and require an adjustment of previously used treatment regimens.

Animals↗
PubMed2001

Antibody-response to three recombinant hepatitis B vaccines: comparative evaluation of multicenter travel-clinic based experience.

The immunogenicity of three currently used hepatitis B vaccines was compared in an unselected study population in an every day travel clinical setting. Five hundred and eighteen vaccinees received Engerix-B (EB), 990 received Twinrix (TWX), and 366 were immunised with Gen-HB-Vax (GHB). Overall, 88.6% of the vaccinees, tested within the first 6 months after completion of the vaccination series, developed protective levels of anti-HBs (> or = 10 mIU/ml). However, GHB recipients showed significantly lower seroprotection rates (SPR) than EB and TWX recipients (79.3% vs. 87.7% vs. 92.3%, P < 0.000001). GMTs for anti-HBs, tested within 6 months after the third vaccination, showed the lowest results in the GHB group, followed by EB and TWX (142 vs. 523 vs. 1008 mIU/ml, P < 0.000001). TWX vaccinees, however, showing a higher antibody decline rate than EB recipients within the first years after completion of the full immunisation course (30% vs. 25%; P = 0.0538). This study confirms an overall good immune response to the 20 microg-dose vaccine, in the course of a regular clinical setting. The significant difference in SPRs and GMTs to the 10 microg-dose vaccine, however, may influence future immunisation practices for the elderly.

Adolescent↗
PubMed2001

Effects of miltefosine and other alkylphosphocholines on human intestinal parasite Entamoeba histolytica.

The protozoan parasite Entamoeba histolytica is the cause of amoebic dysentery and liver abscess. It is therefore responsible for significant morbidity and mortality in a number of countries. Infections with E. histolytica are treated with nitroimidazoles, primarily with metronidazole. At this time, there is a lack of useful alternative classes of substances for the treatment of invasive amoebiasis. Alkylphosphocholines (alkyl-PCs) such as hexadecyl-PC (miltefosine) were originally developed as antitumor agents, but recently they have been successfully used for the treatment of visceral leishmaniasis in humans. We examined hexadecyl-PC and several other alkyl-PCs with longer alkyl chains, with and without double bond(s), for their activity against two strains of E. histolytica. The compounds with the highest activity were oleyl-PC, octadecyl-PC, and nonadecenyl-PC, with 50% effective concentrations for 48 h of treatment between 15 and 21 microM for strain SFL-3 and between 73 and 98 microM for strain HM-1:IMSS. We also tested liposomal formulations of these alkyl-PCs and miltefosine. The alkyl-PC liposomes showed slightly lower activity, but are expected to be well tolerated. Liposomal formulations of oleyl-PC or closely related alkyl-PCs could be promising candidates for testing as broad-spectrum antiprotozoal and antitumor agents in humans.

Animals↗
PubMed2001

In vivo-in vitro model for the assessment of clinically relevant antimalarial cross-resistance.

Cross-resistance may be considered one of the most important factors leading to decreased drug susceptibility of Plasmodium falciparum. The study aimed to determine whether clinically relevant cross-sensitivity of P. falciparum existed between artemisinin and mefloquine. Seventy-six patients with falciparum malaria were admitted and treated with artemisinin derivatives. Treatment response parameters were assessed and in vitro drug sensitivity tests were performed with artemisinin, mefloquine, quinine, and chloroquine. Distinct in vitro cross-sensitivity between artemisinin and mefloquine was observed (p = 0.604; P < 0.001). To assess the relevance of this finding for clinical cross-resistance, we used an analytical model based on the relation of in vivo treatment response parameters (fever, parasite and symptom clearance) to a single reference drug with in vitro drug sensitivity data of several other drugs. Artemisinin (R = 0.554; P = 0.009) and mefloquine (R = 0.615; P = 0.002) in vitro drug sensitivities were equally well reflected in the in vivo treatment response to artemisinin, thereby suggesting the clinical relevance of in vitro cross-sensitivity.

Adult↗
PubMed2000

Seroprevalence of diphtheria immunity among injured adults in Austria.

Over a period of 1 year a seroepidemiological study was conducted at the outpatient clinic of a trauma department. Immunity to diphtheria was determined in serum samples from 558 injured patients (205 women and 353 men, age from 18 to 70). Diphtheria-antitoxin concentrations were measured with an enzyme immunoassay and a tissue culture toxin-neutralization assay. Sero-immunity was classified as susceptibility (<0.01 IU/ml), basic protection (0.01-<0.1 IU/ml) and full protection (>/=0.1 IU/ml) against the toxic manifestations of the disease. A total of 27.1% of the subjects were susceptible to diphtheria, 26.5% had basic protection, and 46.4% were fully protected. The median antitoxin concentration reached 0.08 IU/ml (0. 0-0.29; quartiles Q25-Q75). A non linear trend toward decreasing immunity with increasing age was observed (P<0.001) and females proved less protected than males (P=0.006). The country of original immunization (Austria, Western European countries, Eastern European countries and Non European countries) had no influence on sero-immunity (P=0.49). Multiple linear regression analysis revealed that age (P<0.001) and gender (P=0.004) had a significant independent influence on diphtheria immunity level, whereas the country of original immunization was not significant (P=0.72).

Adolescent↗
PubMed2000

Local and systemic immune responses to combined vibrio cholerae CVD103-HgR and salmonella typhi ty21a live oral vaccines after primary immunization and reimmunization.

The local and systemic antibody responses elicited following concomitant primary immunization and reimmunization with the live oral attenuated Vibrio cholerae CVD103-HgR and Salmonella typhi Ty21a vaccine strains were determined in healthy adult volunteers. A more pronounced serum vibriocidal antibody response was generated after primary immunization compared to reimmunization 2.5 or 3.5 yr later. The seroconversion rate (> or =4-fold rise over baseline) was 81% subsequent to primary immunization versus 57% (p=0.018) and 65% (p=0.639) upon reimmunization at 2.5 and 3.5 yr, respectively. A similar trend was observed for serum anti-S. typhi lipopolysaccharide (LPS) antibodies. After primary immunization, 48% of subjects manifested a significant rise in coproantibody levels to V. cholerae LPS while 60% did so for cholera toxin (CT). Upon reimmunization, the response rate for LPS ranged from 38% at 2.5 yr to 56% at 3.5 yr (p>0.05), while that for CT varied from 31% (p=0. 007) to 50% (p=0.541) at 2.5 and 3.5 yr, respectively. The anti-S. typhi IgA coproantibody response rate was 70% subsequent to primary immunization versus 47% at 2.5 yr (p=0.021) and 63% at 3.5 yr (p=0. 77).

Adult↗
PubMed2000

Mefloquine concentration profiles during prophylactic dose regimens.

A pharmacokinetic study with (malaria) prophylactic doses of mefloquine hydrochloride was conducted in 12 healthy adult subjects (Caucasians), 6 females and 6 males, mean age 29.2 +/- 6.4 years, mean weight 70.6 +/- 13.4 kg. Doses of 250 mg mefloquine were administered on days 0, 1, 7, 14, 21 and 28. Six subjects received a further 5 weekly doses of 250 mg mefloquine, the others 5 further weekly doses of 125 mg. After the third dose the protective threshold mefloquine concentration in blood plasma was achieved in all subjects. In female subjects, mean Cmin ss, Cmax ss and AUCd 0-35 were significantly higher than in males. After the fifth dose, mean Cmax in females reached 1692 ng/ml (4.48 mumol/l), equivalent to a high therapeutic concentration. This is apparently due to a generally lower body weight and a narrower volume of distribution in women. Adverse reactions were significantly more frequent in women than in men. Headache, anorexia, insomnia and vertigo were the most common side effects. The lesser tolerability of mefloquine in females may be due to the higher drug concentrations in this group. This may indicate the need for appropriate adjustment of the prophylactic dose regimen of mefloquine in females.

Adult↗
PubMed2000

[Congenital malaria due to Plasmodium falciparum and Plasmodium malariae].

Increasing tourism and growing numbers of immigrants from malaria-endemic countries are leading to a higher importation rate of rare tropical disorders in European countries. We describe, to the best of our knowledge, the first case of connatal malaria in Austria. The patient is the first child of a 24 year old mother who was born in Ghana and immigrated to Austria one and a half years before delivery. She did not stay in an endemic region during this period and did not show fever or any other signs of malaria. The boy was healthy for the first six weeks of his life. In the 8th week of life he was admitted to our hospital due to persistent fever of unknown origin. On physical examination he showed only mild splenomegaly. Routine laboratory testing revealed mild hemolytic anemia with a hemoglobin value of 8.3 g/l. In the blood smear Plasmodium falciparum and Plasmodium malariae were detected. Oral therapy with quinine hydrochloride was successful and blood smears became negative for Plasmodia within 6 days. This case shows that congenital malaria can occur in children of clinically healthy women who were born in malaria-endemic areas even one and a half year after they have immigrated to non-endemic regions.

Adult↗
PubMed2000

Effect on diphtheria immunity of combined tetanus and diphtheria booster vaccination in adults.

The effect of a single booster injection of an adult formulation of a combined diphtheria-tetanus vaccine (Td) on diphtheria-specific immunity was evaluated. The booster injection, containing 2 IU diphtheria toxoid per dose, was given as part of the surgical wound management for adults with open soft tissue injuries. Diphtheria antitoxin concentrations were determined in serum samples from 534 patients (199 women and 335 men, aged 18-70 years) using an enzyme immunoassay and a tissue culture toxin neutralization assay. Seroimmunity against diphtheria toxin was classified at three levels: susceptibility, basic protection, and full protection against the toxic manifestations of the disease. Before vaccination, 27.1% of the subjects were susceptible to diphtheria, 26.5% had basic protection, and 46.4% were fully protected. Six weeks (minimum 25 days, maximum 98 days) after a single booster injection, 89.7% of the subjects achieved full protection against diphtheria, and only 3.9% had antitoxin levels below the protective level. The median increase from the prevaccination to postvaccination antitoxin concentration was found to be 14-fold (4.4-47; quartiles Q25 to Q75). The change in antitoxin levels after revaccination was higher in older age groups (P< 0.001), whereas neither sex (P = 0.86) nor the country of previous immunization with a different national immunization schedule (P=0.61) had a significant influence on the revaccination effect. Systemic adverse reactions were rare, and local reactions of clinical significance were reported in only 1.9% of subjects.

Adolescent↗
PubMed2000

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Journal Article↗
PubMed2000

Different HBs antibody versus lymphoproliferative responses after application of a monovalent (hepatitis B) or combined (hepatitis A + hepatitis B) vaccine.

BACKGROUND: The aim of the study was to evaluate a possible adjuvanticity of simultaneous hepatitis A (HAV) vaccination for the development of HBs-specific antibodies and lymphoproliferative responses in prophylactic immunization with hepatitis B (HBV). METHODS: Thirty-nine volunteers were vaccinated (schedule: 0/1/6 months) either with a bivalent HAV/HBV (18 individuals) or with HBV (recombinant HBs-antigen) vaccine alone (21 individuals). Anti-HBs antibody titers and lymphoproliferative responses as consequence of stimulation of peripheral blood mononuclear cells (PBMC) with HBs were evaluated and compared between the two groups before second vaccination, before and 1 month after booster. RESULTS: Geometric mean titers were higher at all time points in the group treated with the combined vaccine. On the other hand, after the booster injection, HBs-induced stimulation indices in PBMC were higher in the group vaccinated with HBs alone. Neither the difference in antibody titers nor in proliferative responses reached the level of statistical significance. Interestingly, the inverse relation between cellular proliferation and antibodies was significant, indicating that cellular reactivity is not in all cases a useful marker to evaluate the intensity of the induced immunity. CONCLUSIONS: The magnitude of the T-lymphocyte response may eventually not be decisive for the subsequent antibody response. Both vaccination strategies led to a cellular and humoral immune response and resulted in protective levels of HBs-specific antibodies.

Adjuvants, Immunologic↗
PubMed2000

Double-blind, randomized, placebo controlled pilot study evaluating efficacy and reactogenicity of an oral ETEC B-subunit-inactivated whole cell vaccine against travelers' diarrhea (preliminary report).

Diarrhea caused by enterotoxigenic E.coli (ETEC) is an important health problem in developing countries and in travelers to these areas. In previous trials formulations of ETEC vaccines containing the B-subunit of cholera toxin, which is antigenically similar to the heat labile enterotoxin of ETEC, and the most prevalent colonization factor antigens of ETEC, were shown to stimulate relevant mucosal immune responses in volunteers from Sweden and Egypt.

Adult↗