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We tested for dengue seroconversion among 104 Israeli young adults who traveled to tropical countries for at least 3 months. Seven (6. 7%) seroconverted during travel; four (3.8%) had immunoglobulin (Ig) M antibodies; one was symptomatic with borderline IgM and a rise in IgG; two others (1.9%) had a rise in IgG titers, without detectable IgM. All four IgM-positive patients had traveled to Southeast Asia.
Sporadic cases of symptomatic hepatitis E virus (HEV) infection have been reported in United States travelers to developing countries, including Mexico and Pakistan. To evaluate the risk of exposure in United States travelers, 356 patients seen in our Travel Clinics were tested for antibodies to HEV before and 6 weeks after traveling. Samples obtained 6 months after traveling were available for 211 travelers. IgG and IgM antibodies to HEV were assayed with HEV ELISA diagnostic kits containing 3 recombinant antigens expressed in Escherichia coli representing immunodominant epitopes within open reading frames 2 and 3 of HEV. Nine patients were IgG seropositive in specimens obtained before travel. Four individuals seroconverted. In all 4 patients, IgG seroconversion was demonstrated in samples obtained at least 6 months after return. Samples obtained 6 weeks after return were seronegative for HEV in all 3 patients for whom such samples were available. Travel destinations were diverse: Thailand, China, Russia, and Peru. These data are consistent with an infection acquired while traveling. None of the seropositive subjects reported any symptoms of hepatitis before or after travel. In the absence of overt disease, these results imply that exposure to HEV resulted in subclinical infections.
Sixty puppies were randomly assigned to receive one of two commercially available combination vaccines, and responses to the canine parvovirus and canine distemper virus components of the vaccines were determined by measuring serum antibody titers. The percentage of puppies that seroconverted to canine parvovirus was significantly higher and the mean time for seroconversion was significantly shorter for puppies that received one of the vaccines than for puppies that received the other vaccine. Percentages of puppies that seroconverted to canine distemper virus were not significantly different.
BACKGROUND: Regular testing of military personnel identifies early HIV infection; this identification provides a sentinel cohort in which to describe the evolving molecular epidemiology of HIV-1 transmission. OBJECTIVE: To describe the prevalence and epidemiologic correlates associated with the acquisition of non-subtype B and drug-resistant HIV infections. DESIGN: Cross-sectional study. SETTING: Military referral hospital. PATIENTS: 95 military personnel with HIV-1 seroconversion. MEASUREMENTS: Self-reported questionnaire, CD4 cell counts, plasma HIV-1 RNA levels, and nucleic acid sequence analysis for drug-resistant mutations and HIV-1 genetic subtype. RESULTS: 95 patients were enrolled between February 1997 and February 1998. The likely geographic location of HIV-1 acquisition was overseas in 8% of patients, the United States in 68%, and either overseas or the United States in 24%. Seven patients (7.4%) had subtype E infection; the remainder had subtype B infection. Eight of 31 (26%) treatment-naive patients had mutations in the reverse transcriptase or protease gene associated with drug resistance. CONCLUSIONS: The percentage of HIV-1 non-subtype B infection and antiretroviral drug-resistant mutations was relatively high in U.S. military personnel with recently acquired HIV-1 infection.
BACKGROUND AND AIMS: The prevalence of positivity to anti-HCV antibodies and the incidence of seroconversion in a group of patients undergoing replacement hemodialytic treatment was evaluated using a retrospective analysis. The study was carried out in a hemodialysis centre with no areas and/or equipment dedicated to patients positive to anti-HCV antibodies. The aim was to check whether the rigid application of universal aseptic precautions, which are always adopted by the centre, are sufficient to prevent contagion by hepatitis C virus in patients undergoing dialysis. METHODS: The study was carried out in patients receiving dialysis in the Centre (74 patients at the start of the observation period) for two years (7/95-7/97). Anti-HCV antibodies were assayed every two months using a third generation ELISA tests and positive results were confirmed by RIBA III test. At the start of the observation period, 10/74 patients showed positive levels of anti-HCV antibodies (13.5%). RESULTS: During the period in question none of the patients with negative levels of anti-HCV antibodies at the start of the study became positive. Of the patients undergoing dialysis after 1/7/95, four were already positive for anti-HCV antibodies and none of the others became positive. CONCLUSIONS: The experience confirms that the application of universal aspeptic precautions may be sufficient to prevent the spread of hepatitis C virus in dialysis centres.
Hepatitis C virus (HCV) seroconversion was detected by routine screening in a haemodialysis patient, Patient 1. Serological investigations were undertaken over the following 3 months to determine if further transmission to other patients on the unit had occurred. No additional cases were identified. Twenty-two haemodialysis patients known to have HCV infection were investigated using molecular epidemiological methods to determine if transmission between patients had occurred. HCV viraemia was demonstrated by polymerase chain reaction in 19 of 22 patients (86%). Genotyping showed that eight patients were infected with genotype 1, three with genotype 3 and eight, including Patient 1, with genotype 2. Phylogenetic analysis of viral sequences from the eight patients with genotype 2 revealed three, including Patient 1,with a novel subtype of HCV type 2, and revealed close similarity between viral sequences from patient 1 and those from one other patient, suggesting transmission. This was consistent with haemodialysis histories. Among other patients with genotype 2, there were two with subtype 2a and three others with three separate novel subtypes, as yet undesignated. With the exception of patient 1, all patients infected with novel subtypes were of Afro-Caribbean origin. The HCV prevalence among patients on the haemodialysis unit was high (14%), which may reflect the ethnicity of our haemodialysis population. This case emphasises the risk of nosocomial transmission and the importance of infection control procedures on haemodialysis units, and highlights the usefulness of molecular epidemiological techniques for the investigation of outbreaks of HCV infection.
The rate of seroconversion from percutaneous needlestick exposure to HIV infection is approximately 0.3 per cent. To investigate the possibility of local confinement of HIV, 100 to 200 nm Tc-99m sulfur colloid particles were injected in the canine model subcutaneously at the knee level and collected proximally at the groin from the cannulated femoral vein and lymphatic channel. Tourniquet compression (250 mm Hg) was used as an intervention to possibly restrict particle spread. It was found that particles arrived in the blood at 2.81 +/- 0.54 minutes, with later arrival in the lymph at 6.0 +/- 1.47 minutes. Tourniquet application delayed the appearance of the particulate matter in the blood up to 7.11 +/- 1.5 minutes and in lymph up to 40.0 +/- 5.10 minutes. The concentration of radioactivity in the lymph was higher than in the venous blood. The distribution of the particles reflected by flux was comparable in both pathways. The accumulation curves did not reach plateaus during 45 minutes in lymph and 15 minutes in blood. Radioactive scanning revealed that about 90 per cent of the injected particles remained locally with gradual release for at least 45 minutes. Our results suggest that HIV, introduced by needlestick injury, can be contained for possible viricidal treatment if the response includes rapid immobilization and tourniquet of the area.
Cats with no prior exposure to cat fleas were exposed to fleas infected with Rickettsia felis and monitored monthly for seroconversion via an indirect fluorescent assay (IFA). Each of 12 cats continually infested with fleas, seroconverted by four months post-exposure. Three of six cats fed on by 50 fleas for 15 minutes once per week also seroconverted by month four. Rickettsia felis DNA was detected by PCR in the blood of five of the 16 cats.
We present a case of an exceptionally late HCV seroconversion in a hemodialysis patient. The clinical case illustrates the difficulty of appropriately and quickly isolating a HCV infected patient, and it demonstrates the necessity to consider all the dialysis patients as potentially infectious patients. The standard precautions in hemodialysis must be applied routinely to all the patients, because the diagnosis of the HCV infection is very often late, and on some occasions it is difficult to interpret correctly the results of the available diagnostic tests.
Seroconversion rates of hepatitis B vaccination with increasing antigen doses, in 77 haemodialysis (HD) patients were studied in randomly divided two groups. The first group received the standard 20 microg recombinant HBsAg (rHBsAg) dose, and the second group 40 microg at the 0, 1st and 2nd months of HD. At the end of the study, there were no statistically significant differences between the two groups in the response rates of protective antibody, but the response was always higher in the second group. On the other hand, strong positive antibody response (> or = 100 mlU/ml) according to dates of each dose were as 7.4%, 13.1%, 28.9% and 42.2% in the first group and 50.0%, 50.0%, 60.0% and 52.9% in the second group respectively, and there were statistically significant differences between the two groups in the first three months. We concluded that vaccination with higher antigen doses resulted in a stronger antibody response in the early period in our HD patients. No HBV infection was observed in these two groups in the study period.
In the paper are stated the data of ten years observations of the occurrences of the seroconversion in the patients at the dyalized treatment in the dyalized center in Tesanj. The seropositiveness to B and C hepatitis was 16.5%, what is the usual percentage for the local population. The serconversion to the positive C hepatitis occurred in one patient, and that in the first year of the dialyzed treatment, what remains the possibility the dyalizis began in the period of the incubation. The separation of the seropositive apparati for the dyalisisi from the rest made the sufficient organizational measure by the dyalized center.
This study determined the proportion of captive juvenile and adult African wild dogs (Lycaon pictus) that developed protective titres of rabies neutralising antibodies following ingestion of a chicken head bait/SAG-2 oral rabies vaccine combination. A single chicken head containing 1.8 ml of SAG-2 vaccine (10(8.0) TCID50/ml) in a plastic blister was fed to each of eight adult and three juvenile wild dogs. Bait ingestion resulted in a significant rise in serum neutralising antibody titres. Overall seroconversion rate was eight out of 11 (72.7%), and all the puppies and five out of eight (62.5%) adults showed potentially protective levels of antibodies on day 31. The mean post-vaccination neutralising antibody titre was within the range reported to be protective against challenge with virulent rabies virus in other species.
Hepatitis C is diagnosed frequently in persons with HIV infection. However, the diagnosis of HIV infection during treatment of hepatitis C has not been reported. We present a case of acute HIV seroconversion in a patient who was not responding to interferon therapy for treatment of hepatitis C.
INTRODUCTION: Patients on hemodialysis belong to a high risk group of patients that are exposed to viral hepatitis. The aim of the study was to evaluate the prevalence and incidence of HCV infection seroconversion in this high risk group of patients. PATIENTS AND METHODS: Patients were followed up from January 1997 until January 2002. During this five-year period, the dialysis population increased. There were 99 patients (58 m/41 f) in January 1997, 43 of them seropositive. Out of 186 patients recorded in January 2002, 44 had anti-HCV antibodies. The following parameters were recorded: sex, age, hemodialysis duration, number of blood transfusions, and hepatitis markers. HCV antibodies were determined by third--generation ELISA method (Behring). RESULTS: The study included 164 patients (75 f/92 m), mean age 47.2 +/- 4.2 years, and mean hemodialysis duration 6.2 +/- 4.2 years. In January 1997, HCV antibodies were detected in 43/99 patients with a prevalence of 43.51%. During five-year follow-up, the highest prevalence of hepatitis C was 44% in 1998, with an extremely high incidence of 40% (8 patients became seropositive). In the first three years of the follow-up, the number of blood transfusions and duration of hemodialysis were the main risk factors for HCV transmission. The mean length of hemodialysis of seropositive patients was 6.92 +/- 4.23 in seropositive patients and 2.44 +/- 1.82 in seronegative patients (p < 0.001). Anti-HCV positive patients received significantly more blood transfusions (8.2 +/- 4.36) as compared to seronegative patients. Upon the introduction of preventive measures in 2000 and 2001, which included strict disinfection of monitors and working surfaces, connecting anti-HCV positive and anti-HCV negative patients to different machines, and use of erythropoietin, the incidence rate decreased, and in January 2002, it was 11% with a prevalence of 25%. CONCLUSION: HCV infection is frequent among hemodialysis patients. The number of blood transfusions and duration of hemodialysis as well as sharing the same dialysis machines were the main risk factors of transmission of HCV infection. The use of erythropoietin and preventive measures, along with the use of appropriate protocols and separation of HCV positive from HCV negative patients led to a decrease in the prevalence and incidence of hepatitis C in our hemodialysis population.
We report a unusual case of neuralgic amyotrophy (NA) occurring during the seroconversion stage of an HIV infection. Combined with previously published cases, our observation suggests that NA associated with HIV could belong to the group of early multiplex mononeuritis. Neurologists should be aware of HIV infection when managing a patient with NA.
We report a case involving orthotopic heart transplantation in which a recipient, known to be serologically negative for hepatitis B virus infection, received a heart from a donor known before transplantation to be hepatitis B surface antigen positive. The recipient was treated prospectively with a combination of hepatitis B immune globulin and hepatitis B vaccine. After 10 months of follow-up, the recipient has not experienced seroconversion or viremia from hepatitis B virus and has remained without symptoms by both clinical and laboratory measurements.
OBJECTIVE: This study was aimed to determine the levels of antibodies against Bordetella pertussis, Haemophilus influenzae type b (Hib) and Poliovirus type 1 in preterm children after immunization with acellular pertussis (Infanrix-DTPa) and Hib conjugate (Hiberix) vaccines as well as inactivated vaccine against poliomyelitis (Imovax Polio). MATERIAL AND METHODS: 32 children were given 3 doses of Infanrix-DTPa and Hiberix vaccines as well as Imovax Polio vaccine. Samples of blood were taken from children 4 weeks after application the 3-rd dose of vaccines and compared with the initial levels of antibodies (seroconversion was evaluated in 32 children immunized with both infanrix-DTPa and Hiberix and in 20 ones immunized with Imovax Polio). We evaluated the postvaccinal immunity against Bordetella pertussis and Hib by means of Immunoenzymatic methods (ELISA), with commercially available test kits (Bordetella pertussis ELISA KIT, Genzyme Virotech GmbH, Rüsselsheim, Germany and BINDAZYME Human Anti Haemophilus Influenzae Enzyme Immunoassay Kit, The Binding Site, Birmingham, U.K.); antibodies against Poliovirus type 1 were assessed using neutralisation method. RESULTS: All the children (100%) demonstrated protective levels of antibodies after Immunization with 3-rd doses of Infanrix-DTPa and Hiberix. Only one child (5%) didn't respond when Imovax Polio was applied. The observed increase of postvaccinal antibodies titers as to all applied antigens was statistically significant (p < 0.05). No significant correlations between birth weight, gestational age and the achieved levels of postvaccinal antibodies were noticed. CONCLUSIONS: Our results prove that nearly all the preterm infants achieve the protective levels of antibodies against pertussis, Hib and poliomyelitis. Hiberix due to its high immunogenicity should be applied in the obligatory vaccination schedules, especially in preterm infants.
A 32-year-old male was admitted to our intensive care unit for low cardiac output syndrome. Echocardiography was suggestive of extensive hypokinesia and the ejection fraction was 0.22. Serological tests, including anti-HIV antibodies (ELISA), were negative. The patient was intubated and an intra-aortic balloon pump was inserted. Twenty-four hours after admission a paracorporeal left ventricular assist device (LVAD-MEDOS) was implanted. The left ventricular function showed progressive improvement with normalization of the ejection fraction on day 19. The device was removed on day 20. Before discharge, the patient admitted that he had had unprotected sex with numerous male acquaintances; anti-HIV testing turned positive. The final diagnosis was fulminant myocarditis during HIV seroconversion.