Jan Groen - Academia.edu (original) (raw)

Papers by Jan Groen

International Journal of Epidemiology, Jun 1, 2001

Journal of Medical Virology, May 1, 1994

Journal of Virological Methods, Feb 1, 1989

Journal of Clinical Microbiology, Feb 1, 2002

European Journal of Epidemiology, Jun 1, 1994

Journal of Clinical Pathology, 1989

Journal of Clinical Microbiology, Mar 1, 2000

Measles continues to be a major childhood disease in terms of global morbidity and mortality. In ... more Measles continues to be a major childhood disease in terms of global morbidity and mortality. In the main areas of its endemicity the only available means of diagnosis are based on clinical criteria: the presence of a maculopapular rash and fever accompanied by cough, coryza, and/or conjunctivitis. We have studied 38 clinically diagnosed cases of measles in Khartoum, Sudan, by means of serology, reverse transcriptase PCR (RT-PCR) on throat swabs and virus isolation from lymphocytes. On the basis of serology, 28 patients were diagnosed as having an acute measles virus (MV) infection, while in 10 cases the clinical symptoms proved to have other causes. It was shown that in cases with low serum immunoglobulin M (IgM) levels, an additional measurement of IgG or virus-neutralizing antibodies was necessary to discriminate between patients with an acute MV infection sampled during an early stage of the disease and patients who had experienced an MV infection in the more distant past. The serological laboratory diagnosis was validated by an MV-specific RT-PCR: for all confirmed measles cases tested a fragment of the correct size which hybridized with a third MV-specific primer could be amplified, while all serologically negative cases were also RT-PCR negative. MV could be isolated from 17 out of 23 of the serologically confirmed cases, demonstrating that virus isolation is less reliable as a diagnostic tool than serology or RT-PCR. This study stresses the urgent need for a rapid diagnostic field test for measles.

Archives of Virology, 1985

Clinical and diagnostic laboratory immunology, Jul 1, 2000

Detection of herpes simplex virus type 2 (HSV-2)-specific antibodies by a monoclonal antibody (MA... more Detection of herpes simplex virus type 2 (HSV-2)-specific antibodies by a monoclonal antibody (MAb)blocking enzyme-linked immunoassay (EIA) was compared with detection by a strip immunoblot assay (SIA) in a sexually transmitted disease (STD) clinic population. The study population consisted of 1,683 genitourinary medicine clinic attendees (582 women and 1,101 men). Sera were tested for the presence of HSV-2 antibody by use of the blocking EIA, in which binding of the MAb AP-1 to HSV-2 glycoprotein G-2 (gG-2) is blocked by HSV-2-specific antibody. The Chiron RIBA HSV-1 and-2 strip immunoassay (SIA) utilizes HSV-1and HSV-2-specific or cross-reactive antigens immobilized on nitrocellulose strips (HSV gB-1 and HSV gG-1 peptide bands specific for HSV-1 antibody, HSV-2 gG-2 band specific for HSV-2 antibody, and HSV gD-2 band cross-reactive for HSV-1 and HSV-2 antibodies). A total of 1,612 sera were tested by MAb-blocking EIA for HSV-2 antibody and by SIA for HSV-1 and HSV-2 antibodies. By EIA, 541 (33.6%) sera were positive for HSV-2 antibody and 1,068 sera were negative for HSV-2 antibody; 3 sera gave equivocal results. HSV-2 antibody was detected in 555 (34.4%) sera by SIA; 144 (26%) of these sera possessed only HSV-2 antibody, and 411 (74%) sera contained both HSV-1 and HSV-2 antibodies. SIA detected HSV-1 antibody in 1,155 (71.6%) sera; 744 (64%) of these sera contained HSV-1 antibody alone. Sixteen sera contained antibody against HSV but could not be typed by SIA. A total of 512 sera were positive for HSV-2 antibody by both the EIA and SIA. We concluded that the blocking EIA and SIA showed a high level of agreement in detecting HSV-2 antibody in this population. In contrast to the SIA, the blocking EIA is a useful tool for large epidemiological studies, though the SIA proved to be slightly more sensitive once sera with discrepant results were further tested.

The Netherlands Journal of Medicine, 2000

Europeans travelling to (sub)-tropical countries have an increased risk for infections with Ricke... more Europeans travelling to (sub)-tropical countries have an increased risk for infections with Rickettsia. As serious consequences are associated with delay in specific antibiotic therapy, unequivocal diagnosis of this condition is needed. We focus here on the benefits of early, and consequences of late laboratory diagnosis, and emphasise the need of an increased awareness of rickettsioses among family doctors, as well as medical specialists, in non-endemic areas when evaluating patients with travel associated fever.

The Pediatric Infectious Disease Journal, 2001

From 28 young children in the Netherlands, we isolated a paramyxovirus that was identified as a t... more From 28 young children in the Netherlands, we isolated a paramyxovirus that was identified as a tentative new member of the Metapneumovirus genus based on virological data, sequence homology and gene constellation. Previously, avian pneumovirus was the sole member of this recently assigned genus, hence the provisional name for the newly discovered virus: human metapneumovirus. The clinical symptoms of the children from whom the virus was isolated were similar to those caused by human respiratory syncytial virus infection, ranging from upper respiratory tract disease to severe bronchiolitis and pneumonia. Serological studies showed that by the age of five years, virtually all children in the Netherlands have been exposed to human metapneumovirus and that the virus has been circulating in humans for at least 50 years.

Journal of Infectious Diseases, 1997

Diagnostic Microbiology and Infectious Disease, 1987

Background: Serologic tests for specific antibody nowadays are widely employed for the diagnosis ... more Background: Serologic tests for specific antibody nowadays are widely employed for the diagnosis of parasitic diseases. Recently, an increasing numbers of kits have adopted enzyme-linked immunosorbent assay (ELISA) for the detection of parasitic antibodies. In this study, we evaluated two ELISA reagents for the diagnosis of parasitic diseases. Methods: A total of 553 serum and 156 CSF samples were assayed using an in-house micro-ELISA and Genedia Ⓡ Ab ELISA (Green cross PBM, Korea) for Cysticercus, Paragonimus westermani, Clonorchis sinensis, and Sparganum. We reviewed the medical records of all patients. The results from Genedia Ⓡ Ab ELISA kit were compared with those from the inhouse micro-ELISA method. Results: The overall concordance rate between the two ELISA tests was 95.5%. When compared with the clinical information, the sensitivity, specificity, positive predictive value, and negative predictive value of the in-house micro-ELISA were 100%, 99.0∼99.6%, 82.4∼96.4%, and 100%, and the respective figures for Genedia Ⓡ Ab ELISA kit were 92.9~100%, 88.0∼ 97.3%, 41.7∼50%, and 99.9~100% with kappa agreement of 0.53-0.63. Comparison of two ELISA methods showed a significant difference (P＜0.05). Retesting of 85 discordant samples showed that the concordance rate of the in-house ELISA was 97.7% and that of Genedia Ⓡ Ab ELISA was 28.2%. Conclusion: Genedia Ⓡ Ab ELISA kit showed an intermediate level of kappa agreement compared with the in-house ELISA. Further studies are necessary to improve the concordance rate of the two methods, and a careful interpretation of these results is required for a precise diagnosis.

Archives of Virology, 2000

Veterinary Microbiology, 1990

During a recent disease outbreak among harbour seals (Phoca vitulina) in the North and Baltic sea... more During a recent disease outbreak among harbour seals (Phoca vitulina) in the North and Baltic seas, more than 17 000 animals have died. The clinical symptoms and pathological findings were similar to those of distemper in dogs. Based on a seroepizootiological study, using a canine distemper virus (CDV) neutralization assay, it was shown that CDV or a closely related morbillivirus (phocid distemper virus-PDV) was the primary cause of the disease. The virus was isolated in cell culture from the organs of dead seals and characterized as a morbillivirus by serology (immunofluorescence neutralization and enzyme-linked immunosorbent assays) and by negative contrast electron microscopy. Experimental infection of SPF dogs resulted in the development of mild clinical signs of distemper and CDV-neutralizing antibodies. The disease was reproduced in seals by experimental inoculation of organ material from animals that had died during the outbreak. However, seals that had been vaccinated with experimental inactivated CDV vaccines were protected against this challenge. This fulfilled the last of Koch's postulates, confirming that the morbillivirus isolated from the seal organs, was the primary cause of the disease outbreak. The recent demonstration of the presence of a similar virus in Lake Baikal seals (Phoca sibirica), which infected these Siberian seals 1 year before the northwestern European seals were infected, raises new questions about the origin of this infectious disease in pinnipeds.

Journal of Virological Methods, 1987

Immuno affinity chromatography with virus neutralizing monoclonal antibodies. directed to the hae... more Immuno affinity chromatography with virus neutralizing monoclonal antibodies. directed to the haemagglutinating protein of canine parvovirus (CPV) was used to purify and concentrate CPV from infected cell culture. The procedure was monitored by testing the respective fractions in an infectivity titration system. in an ELISA. in a haemagglutination assay and by negative contrast electron microscopy to quantify CPV or CPV antigen. The degree of purification was further estimated by testing the fractions for total protein content in a calorimetric method, for bovine serum albumin content in an ELISA and by SDS-PAGE. Over 99% of the contaminating proteins proved to be removed. and 2O?i or 70-90% of infectious CPV or CPV antigen. respectively, was recovered.

Journal of Virological Methods, 1996

Potency control of inactivated rabies vaccines for human and veterinary application is usually un... more Potency control of inactivated rabies vaccines for human and veterinary application is usually undertaken by vaccination-challenge tests (e.g. the mouse potency test). For practical and ethical reasons there is an urgent need to replace in vivo potency control procedures, at least in part, by reliable methods of in vitro potency testing. Quantitative ELISA s,ystems for potency control were developed using monoclonal antibodies (MAbs) directed to the glycoprotein (GP) and to the nucleoprotein (NP) of the virus. Although immuno-capture and competition ELISAs for GP measurement had almost equal sensitivity (detection level GP < 0.1 IU), the competition data showed the best correlation with potency values when a panel of rabies vaccines for human use was tested (r = 0.88, n = 10). The NP values for this panel of vaccines in the competition system (detection level NP < 1 IU) also correlated well with potency values (r = 0.90, n = 10). The competition system proved to be best also with liquid adjuvanted veterinary rabies vaccines of LEAP, PM, PV and SAD origin. The implementation of ELISA systems for potency control of rabies vaccines is discussed.