Biomedical subjects

Wim H M van der Poel

Publications and source records attributed to Wim H M van der Poel.

9 recordsLinked to original sources

PubMed2025

Deep Sequencing Reveals Dual Evolution of SARS-CoV-2: Insights Into Defective Genomes From Wuhan-Hu-1 Variants to Omicron Subvariants.

SARS-CoV-2 has evolved from early variants dominating the first (B.1.5, B.1.1) and second (B.1.177) pandemic waves, which exhibited a higher frequency of minority mutants with deletions leading to Defective Viral Genomes (DVGs) in the spike region near the S1/S2 cleavage site than the Alpha, Beta, and Delta variants. The emergence of Omicron has significantly altered the dominant variant profile, with Omicron subvariants now representing 100% of circulating viruses. To monitor the evolution and adaptation of Omicron in the human population, a deep-sequencing study was performed in RNA samples of BA.1, BA.1.1, BA.2, BA.5, BQ.1.1, XBB.1.5 and BA.2.86 Omicron subvariants. The findings reveal two occurrences of similar evolutionary patterns within SARS-CoV-2 characterized by a shift from a significant to a very low production of DVGs. This event suggests that DVGs might play a role in the virus's spread and adaptation for persistence in infected humans.

SARS-CoV-2↗

PubMed2006

Public health awareness of emerging zoonotic viruses of bats: a European perspective.

Bats classified in the order Chiroptera are the most abundant and widely distributed non-human mammalian species in the world. Several bat species are reservoir hosts of zoonotic viruses and therefore can be a public health hazard. Lyssaviruses of different genotypes have emerged from bats in America (Genotype 1 rabies virus; RABV), Europe (European bat lyssavirus; EBLV), and Australia (Australian bat lyssavirus; ABLV), whereas Nipah virus is the most important recent zoonosis of bat origin in Asia. Furthermore, some insectivorous bat species may be important reservoirs of SARS coronavirus, whereas Ebola virus has been detected in some megachiropteran fruit bats. Thus far, European bat lyssavirus (EBLV) is the only zoonotic virus that has been detected in bats in Europe. New zoonotic viruses may emerge from bat reservoirs and known ones may spread to a wider geographical range. To assess future threats posed by zoonotic viruses of bats, there is a need for accurate knowledge of the factors underlying disease emergence, for an effective surveillance programme, and for a rapid response system. In Europe, primary efforts should be focussed on the implementation of effective passive and active surveillance systems for EBLVs in the Serotine bat, Eptesicus serotinus, and Myotis species (i.e., M. daubentonii and M. dasycneme). Apart from that, detection methods for zoonotic viruses that may emerge from bats should be implemented. Analyses of data from surveillance studies can shed more light on the dynamics of bat viruses, (i.e., population persistence of viruses in bats). Subsequently, studies will have to be performed to assess the public health hazards of such viruses (i.e., infectivity and risk of infection to people). With the knowledge generated from this kind of research, a rapid response system can be set up to enhance public health awareness of emerging zoonotic viruses of bats.

Animals↗

PubMed2006

Detection of noroviruses in foods: a study on virus extraction procedures in foods implicated in outbreaks of human gastroenteritis.

Disease outbreaks in which foods are epidemiologically implicated as the common source are frequently reported. Noroviruses and enteric hepatitis A viruses are among the most prevalent causative agents of foodborne diseases. However, the detection of these viruses in foods other than shellfish is often time-consuming and unsuccessful. In this study, three virus concentration methods were compared: polyethylene glycol (PEG) plus NaCl, ultracentrifugation, and ultrafiltration. Two RNA extraction methods, TRIzol and RNeasy Mini Kit (Qiagen), were compared for detection of viruses in whipped cream and lettuce (as representatives of the dairy and vegetable-fruit food groups, respectively). A seeding experiment with canine calicivirus was conducted to determine the efficiency of each virus extraction procedure. The PEG-NaCl-TRIzol method was most efficient for the detection of viruses in whipped cream and the ultracentrifugation-RNeasy-Mini Kit procedure was best for detection on lettuce. Based on the seeding experiments, food items implicated in norovirus-associated gastroenteritis outbreaks were subjected to the optimal procedure for a specific composition and matrix. No noroviruses were detected in the implicated food items, possibly because the concentration of virus on the food item was too low or because of the presence of inhibitory factors. For each food group, a specific procedure is optimal. Inhibitory factors should be controlled in these procedures because they influence virus detection in food.

Centrifugation↗

PubMed2003

Epidemiology of Norwalk-like virus infections in cattle in The Netherlands.

"Norwalk-like viruses" (NLVs) are the most common cause of acute non-bacterial gastroenteritis in humans. Cattle may be a reservoir of NLVs although never bovine NLVs have been found in humans. To gain more insight into the epidemiology of NLV, infections in cattle in The Netherlands were studied. Individual faecal samples from a large dairy herd and 243 pooled samples from veal calf farms were analysed for NLV by RT-PCR. Calves under 3 months of age in the dairy herd were sampled three to five times with 3-week intervals, whereas dairy cattle were sampled twice with a 2-month interval. In 31.6% (77/243) of the veal calf farm samples and in 4.2% (13/312) of the individual dairy cattle samples NLV was detected. The mean age of virus positive dairy cattle was 2.5 months. The highest numbers of NLV positive veal calf farms in The Netherlands were found in the regions with the highest number of veal calf farms. NLV infected veal calf farms were detected in every month throughout the study period. Cattle appeared to be hosts of NLVs, and virus shedding was weakly associated with diarrhoea. Complete ORF2 sequences were obtained from two calf NLVs and phylogenetic analyses suggested that these strains belong to a distinct cluster (GGIII/2) in between GGI and GGII NLVs of humans. Overall, genetic variation between strains as determined by sequence analysis of the P1/P2 capsid region was limited to 14.6%. Our data shows that NLV is endemic in the cattle population in The Netherlands and genetically distinct from NLVs in humans.

Animals↗

PubMed2003

Rabies in wildlife in Latvia.

In the Baltic States, lyssaviruses are often detected in wildlife and presumed to constitute an important public health hazard. In order to decrease rabies incidence and eradicate wildlife reservoirs, a national rabies eradication program has been in place. Since 1970 a vaccination program in dogs and cats has been executed, and in 1991 oral vaccination of foxes was started. However, due to an insufficient budget, the latter was not done regularly and nationwide before 2000. Now, the program in force consists of compulsory vaccination of all dogs and cats, and a tetracycline marker vaccine oral vaccination program of foxes in the whole country. In 2001, 151 of 285 (53%) fox jaws were tested positive for tetracycline. All animals showing rabies-like symptoms were killed and tested for rabies. In this way, 250-400 cases of rabies per year were diagnosed in wildlife. To molecularly characterize the prevalent lyssaviruses in wildlife, lyssavirus RNA of 25 recent rabies positive samples, collected in the year 1999, was amplified by RT-PCR. Direct sequencing of the RT-PCR-amplified products of the virus' nucleoprotein encoding region and subsequent sequence analyses resulted in a 99.3-100% homology between isolates and a 99.0-100% similarity with a 1995 genotype I, classical rabies virus (RABV) raccoon dog isolate from Estonia. These results confirmed that RABV is endemic in wildlife in Latvia and should be considered a serious public health threat. To successfully eradicate the wildlife reservoirs, the national rabies eradication program must be continued, and it may need to be intensified.

Animals↗

PubMed2003

Study of lyssaviruses of bat origin as a source of rabies for other animal species in the State of Rio De Janeiro, Brazil.

An epidemic-geographic rabies study was carried out in which 72 animal and human brain samples were analyzed for Lyssaviruses by a direct immunofluorescent technique (DIFT) and a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Fifty-two samples were also tested by a mouse inoculation test. Lyssavirus RNA was detected in 60 of 72 samples. Five DIFT-negative bat samples tested by a nested PCR assay showed evidence of the presence of rabies virus RNA. Sequencing of amplified rabies virus nucleoprotein encoding segments of a selection of the samples resulted in the formation of clusters, corresponding to samples originating from cattle and equines from the same hydrographic basin. Genomically related Lyssavirus strains of bat origin were found in each cluster, most likely because of the role of the bat in the epidemiology of the virus. All samples studied were of genotype 1. With exception of the human sample, all were distinct from the reference sample.

Animals↗

PubMed2002

Cluster of cases of acute hepatitis associated with hepatitis E virus infection acquired in the Netherlands.

Increasing evidence suggests that hepatitis E virus (HEV) infection may occur in developed countries and that swine may act as a reservoir. We report a cluster of 2 confirmed cases and 1 presumptive case of hepatitis associated with HEV. The typed strain from 1 case was related to HEV strains found in North America and Europe, and it was also related to a cluster of swine HEV strains found in The Netherlands. Our findings indicate that locally acquired HEV infections in industrialized countries may be overlooked. Routine testing for HEV infection in patients with acute hepatitis in The Netherlands should be considered before a diagnosis of autoimmune hepatitis is reached and steroid therapy is initiated.

Acute Disease↗

PubMed2002

Hepatitis E: an overview.

The hepatitis E virus (HEV) is a non-enveloped, positive-sense, single-stranded RNA virus with icosahedral symmetry. Although it is related to the alpha-virus superfamily, the HEV is classified as a separate Hepatitis E-like viruses genus. Infection in humans occurs in sporadic and epidemic forms and can cause an acute, self-limited, icteric hepatitis. Recent studies indicate the existence of a reservoir in animals.

Adolescent↗

PubMed2002

An outbreak of diarrhea in a neonatal medium care unit caused by a novel strain of rotavirus: investigation using both epidemiologic and microbiological methods.

OBJECTIVE: In December 1999, an outbreak of diarrhea was reported in a general hospital neonatal medium care unit (NMCU) caused by a novel strain of rotavirus with genotype P[6], G9. An investigation was conducted to determine risk factors for illness among neonates. DESIGN: Rotavirus diagnosis was by latex agglutination and typing by reverse transcriptase polymerase chain reaction. A case-control study was performed using data collected from medical records on exposures in a 3-day period before illness (cases) or a random 3-day period (controls). Environmental swabs were tested for rotavirus. Antenatal blood samples from mothers and blood samples provided by hospital staff were analyzed for rotavirus antibodies. RESULTS: Fifty-six cases of rotaviral illness were confirmed by latex agglutination. Forty-seven of these were among 118 neonates exposed to the NMCU (attack rate, 40%). There was a 4-week period with no clinical cases in the course of the outbreak. Increased frequency (> or = 15 times in 3 days) of ungloved nasogastric feeding was a significant risk factor (adjusted odds ratio, 8.79), controlling for birth weight and gestational age. Environmental sampling showed persistence of the virus on ward surfaces despite cleaning. None of 24 NMCU staff members had high levels of antibodies against P[6], G9. Three (8%) of 38 mothers had high antibody levels; 2 had infants who became ill. The outbreak ended with a 7-day ward closure, disinfection, and introduction of gloved nasogastric feeding. CONCLUSIONS: Case-control studies can be successful in identiffying risk factors for nosocomial outbreaks of diarrhea. High levels of rotavirus antibodies in mothers may not protect infants. The environment may be the most important reservoir of rotavirus during outbreaks.

Case-Control Studies↗