Showing papers by "Chinese Center for Disease Control and Prevention published in 2004"

VFDB: a reference database for bacterial virulence factors.

Abstract: Bacterial pathogens continue to impose a major threat to public health worldwide in the 21st century. Intensified studies on bacterial pathogenesis have greatly expanded our knowledge about the mechanisms of the disease processes at the molecular level over the last decades. To facilitate future research, it becomes necessary to form a database collectively presenting the virulence factors (VFs) of various medical significant bacterial pathogens. The aim of virulence factor database (VFDB) (http://www.mgc.ac.cn/VFs/) is to provide such a source for scientists to rapidly access to current knowledge about VFs from various bacterial pathogens. VFDB is comprehensive and user-friendly. One can search VFDB by browsing each genus or by typing keywords. Furthermore, a BLAST search tool against all known VF-related genes is also available. VFDB provides a unified gateway to store, search, retrieve and update information about VFs from various bacterial pathogens.

Hematotoxicity in Workers Exposed to Low Levels of Benzene

Abstract: Benzene is known to have toxic effects on the blood and bone marrow, but its impact at levels below the U.S. occupational standard of 1 part per million (ppm) remains uncertain. In a study of 250 workers exposed to benzene, white blood cell and platelet counts were significantly lower than in 140 controls, even for exposure below 1 ppm in air. Progenitor cell colony formation significantly declined with increasing benzene exposure and was more sensitive to the effects of benzene than was the number of mature blood cells. Two genetic variants in key metabolizing enzymes, myeloperoxidase and NAD(P)H:quinone oxidoreductase, influenced susceptibility to benzene hematotoxicity. Thus, hematotoxicity from exposure to benzene occurred at air levels of 1 ppm or less and may be particularly evident among genetically susceptible subpopulations.

Superspreading SARS events, Beijing, 2003.

Abstract: Superspreading events were pivotal in the global spread of severe acute respiratory syndrome (SARS). We investigated superspreading in one transmission chain early in Beijing’s epidemic. Superspreading was defined as transmission of SARS to at least eight contacts. An index patient with onset of SARS 2 months after hospital admission was the source of four generations of transmission to 76 case-patients, including 12 healthcare workers and several hospital visitors. Four (5%) case circumstances met the superspreading definition. Superspreading appeared to be associated with older age (mean 56 vs. 44 years), case fatality (75% vs. 16%, p = 0.02, Fisher exact test), number of close contacts (36 vs. 0.37) and attack rate among close contacts (43% vs. 18.5%, p < 0.025). Delayed recognition of SARS in a hospitalized patient permitted transmission to patients, visitors, and healthcare workers. Older age and number of contacts merit investigation in future studies of superspreading.

School-milk intervention trial enhances growth and bone mineral accretion in Chinese girls aged 10-12 years in Beijing

Abstract: A 2-year milk intervention trial was carried out with 757 girls, aged 10 years, from nine primary schools in Beijing (April 1999 - March 2001). Schools were randomised into three groups: group 1, 238 girls consumed a carton of 330 ml milk fortified with Ca on school days over the study period; group 2, 260 girls received the same quantity of milk additionally fortified with 5 or 8 microg cholecalciferol; group 3, 259 control girls. Anthropometric and bone mineralisation measurements, as well as dietary, health and physical-activity data, were collected at baseline and after 12 and 24 months of the trial. Over the 2-year period the consumption of this milk, with or without added cholecalciferol, led to significant increases in the changes in height (> or =0.6 %), sitting height (> or =0.8 %), body weight (> or 2.9 %), and (size-adjusted) total-body bone mineral content (> or =1.2 %) and bone mineral density (> or =3.2 %). Those subjects receiving additional cholecalciferol compared with those receiving the milk without added 25-hydoxycholecalciferol had significantly greater increases in the change in (size-adjusted) total-body bone mineral content (2.4 v. 1.2 %) and bone mineral density (5.5 v. 3.2 %). The milk fortified with cholecalciferol significantly improved vitamin D status at the end of the trial compared with the milk alone or control groups. It is concluded that an increase in milk consumption, e.g. by means of school milk programmes, would improve bone growth during adolescence, particularly when Ca intake and vitamin D status are low.

Risk factors for SARS among persons without known contact with SARS patients, Beijing, China.

Abstract: Most cases of severe acute respiratory syndrome (SARS) have occurred in close contacts of SARS patients. However, in Beijing, a large proportion of SARS cases occurred in persons without such contact. We conducted a case-control study in Beijing that compared exposures of 94 unlinked, probable SARS patients with those of 281 community-based controls matched for age group and sex. Case-patients were more likely than controls to have chronic medical conditions or to have visited fever clinics (clinics at which possible SARS patients were separated from other patients), eaten outside the home, or taken taxis frequently. The use of masks was strongly protective. Among 31 case-patients for whom convalescent-phase (>21 days) sera were available, 26% had immunoglobulin G to SARS-associated coronavirus. Our finding that clinical SARS was associated with visits to fever clinics supports Beijing's strategy of closing clinics with poor infection-control measures. Our finding that mask use lowered the risk for disease supports the community's use of this strategy.

The HIV/AIDS epidemic in China: history, current strategies and future challenges.

Abstract: This article reviews the epidemic of HIV infection and AIDS, the Chinese national policy development in response to the epidemic, and disparities between policies and the need for AIDS prevention in China. The HIV epidemic in China has gone through three phases, and it is now at the rapid expansion phase. Since 1988, HIV/AIDS has been addressed from a legal perspective, but in the early stages laws and regulations actually hindered HIV control efforts. Since 1995 efforts have been made to improve policy decisions. Two major strategic plans were issued in 1998 and 2001, with increased government funding for implementation. Although the challenges facing HIV/AIDs control in China are many, the Chinese government is making a stronger commitment for implementing effective AIDS control measures in the country.

First Report from the Asian Rotavirus Surveillance Network

Abstract: Rotavirus remains the most common cause of severe, dehydrating diarrhea among children worldwide. Several rotavirus vaccines are under development. Decisions about new vaccine introduction will require reliable data on disease impact. The Asian Rotavirus Surveillance Network, begun in 2000 to facilitate collection of these data, is a regional collaboration of 36 hospitals in nine countries or areas that conduct surveillance for rotavirus hospitalizations using a uniform World Health Organization protocol. We summarize the Network's organization and experience from August 2001 through July 2002. During this period, 45% of acute diarrheal hospitalizations among children 0–5 years were attributable to rotavirus, higher than previous estimates. Rotavirus was detected in all sites year-round. This network is a novel, regional approach to surveillance for vaccine-preventable diseases. Such a network should provide increased visibility and advocacy, enable more efficient data collection, facilitate training, and serve as the paradigm for rotavirus surveillance activities in other regions.

Oxidative damage-related genes AKR1C3 and OGG1 modulate risks for lung cancer due to exposure to PAH-rich coal combustion emissions.

Abstract: Lung cancer rates among men and particularly among women, almost all of whom are non-smokers, in Xuan Wei County, China are among the highest in China and have been causally associated with exposure to indoor smoky coal emissions that contain very high levels of polycyclic aromatic hydrocarbons (PAHs). As such, this population provides a unique opportunity to study the pathogenesis of PAH-induced lung cancer that is not substantially influenced by the large number of other carcinogenic constituents of tobacco smoke. Aldo-keto reductases (AKRs) activate PAH dihydrodiols to yield their corresponding reactive and redox-active o-quinones, which can then generate reactive oxygen species that cause oxidative DNA damage. We therefore examined the association between single nucleotide polymorphisms (SNPs) in four genes (AKR1C3-Gln5His, NQO1-Pro187Ser, MnSOD-Val16Ala and OGG1-Ser326Cys) that play a role in the generation, prevention or repair of oxidative damage and lung cancer risk in a population-based, case-control study of 119 cases and 113 controls in Xuan Wei, China. The AKR1C3-Gln/Gln genotype was associated with a 1.84-fold [95% confidence interval (CI) = 0.98-3.45] increased risk and the combined OGG1-Cys/Cys and Ser/Cys genotypes were associated with a 1.93-fold (95% CI = 1.12-3.34) increased risk of lung cancer. Subgroup analysis revealed that the effects were particularly elevated among women who had relatively high cumulative exposure to smoky coal. SNPs in MnSOD and NQO1 were not associated with lung cancer risk. These results suggest that SNPs in the oxidative stress related-genes AKR1C3 and OGG1 may play a role in the pathogenesis of lung cancer in this population, particularly among heavily exposed women. However, due to the small sample size, additional studies are needed to evaluate these associations within Xuan Wei and other populations with substantial exposure to PAHs.

Molecular epidemiology of enterovirus 71 infection in the Western Pacific Region

Abstract: Background: Recently, there have been large outbreaks of hand, foot and mouth disease (HFMD) mainly caused by enterovirus 71 (EV71) associated with severe neurological diseases in the Western Pacific Region (WPR) To monitor the realtime trend of EV71 transmission throughout the WPR, the authors conducted a molecular epidemiological analysis of EV71 infection Methods: Viruses were isolated from clinical samples from patients with HFMD or those with neurological complications The EV71 isolates were identified by microneutralization assay The VP4 and/or VP1 regions of recent EV71 isolates were sequenced and subjected to phylogenetic analysis using reference EV71 strains Results: The phylogenetic analysis of EV71 isolates from the WPR revealed two major genogroups, B and C, based on the nucleotide sequence alignment of the VP1 or VP4 region These two major genogroups were further divided into subgenogroups, B1, B2, B3, and B4 and C1, C2, C3 and C4, respectively Conclusion: The molecular epidemiological analyses of recent and previous EV71 isolates in the WPR indicated that two major genogroups of EV71 are co-circulating in Australia, Malaysia, Singapore, Taiwan and Japan Recent EV71 isolates in Mainland China constitute a new distinct genetic cluster, subgenogroup C4 Two major lineages of EV71 are the major causative agents of the present HFMD epidemics in the WPR and both are considered to be neurovirulent

Neutralizing Antibodies in Patients with Severe Acute Respiratory Syndrome-Associated Coronavirus Infection

Abstract: Background Severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) is the principal etiologic agent of SARS. We analyzed serum samples obtained from 623 patients with SARS in Beijing, to determine whether infection with SARS-CoV can elicit neutralizing antibodies (NAbs). Methods We developed a highly sensitive and safe neutralization assay using the SARS-CoV pseudotyped virus and used this assay to determine the titers of the NAbs in serum samples from patients with SARS. Results We found that 85.9% of serum samples contained NAbs against SARS-CoV and that most of the NAb activities could be attributed to immunoglobulin G. The NAbs became detectable first at 5-10 days after the onset of symptoms, and their levels peaked at 20-30 days and then were sustained for >150 days. The serum samples could neutralize the pseudotype particles bearing the spike glycoproteins from different SARS-CoV strains, suggesting that the NAbs to SARS-CoV were broadly reactive. Conclusions NAbs to SARS-CoV are broadly elicited in patients with SARS and, according to their kinetics, may correlate with viral load during the early stages of the disease. These results suggest that it is possible to develop effective vaccines against SARS and that NAbs provide a potential strategy for treating patients with SARS.

Laboratory diagnosis of four recent sporadic cases of community-acquired SARS, Guangdong Province, China.

Abstract: Four cases of severe acute respiratory syndrome (SARS) that occurred from December 16, 2003, to January 8, 2004, in the city of Guangzhou, Guangdong Province, China, were investigated. Clinical specimens collected from these patients were tested by provincial and national laboratories in China as well as members of the World Health Organization SARS Reference and Verification Laboratory Network in a collaborative effort to identify and confirm SARS-associated coronavirus (SARS-CoV) infection. Although SARS-CoV was not isolated from any patient, specimens from three patients were positive for viral RNA by reverse transcription–polymerase chain reaction assay, and all patients had detectable rises in SARS-CoV–specific antibodies. This study shows the effectiveness of a collaborative, multilaboratory response to diagnose SARS.

Inhibition of Severe Acute Respiratory Syndrome Virus Replication by Small Interfering RNAs in Mammalian Cells

Abstract: Severe acute respiratory syndrome (SARS) is an acute respiratory infectious disease that spread worldwide in early 2003. The cause was determined as a novel coronavirus (CoV), SARS-associated CoV (SARS-CoV), with a single-stranded, plus-sense RNA. To date, no effective specific treatment has been identified. To exploit the possibility of using RNA interference as a therapeutic approach to fight the disease, plasmid-mediated small interfering RNAs (siRNAs) were generated to target the SARS-CoV genome. The expression of siRNAs from two plasmids, which specifically target the viral RNA polymerase, effectively blocked the cytopathic effects of SARS-CoV on Vero cells. These two plasmids also inhibited viral replication as shown by titer assays and by an examination of viral RNA and protein levels. Thus, our results demonstrated the feasibility of developing siRNAs as effective anti-SARS drugs.

The current state of public health in China.

Abstract: In the past 50 years, China has made great achievements in controlling infectious diseases and improving the public's health and hygiene. However, in the twenty-first century, owing to the negative effects brought on by aging of the population and the burdens of diseases, urbanization, industrialization, and globalization, Chinese public health officials are encountering greater difficulties than ever. Old operating models of public health cannot meet present requirements. The main problems are poor capacity to respond to public health emergencies, severe inequality of health care services, and lagging development of public health information systems. Public health in China can gradually meet the requirements of social development and the increasing public demand for health care services only when the public health is directed by informatization, globalization, technification, and humanization.

Long-term SARS coronavirus excretion from patient cohort, China

Abstract: This study investigated the long-term excretion of severe acute respiratory syndrome-associated coronavirus in sputum and stool specimens from 56 infected patients. The median (range) duration of virus excretion in sputa and stools was 21 (14-52) and 27 (16-126) days, respectively. Coexisting illness or conditions were associated with longer viral excretion in stools.

Foodborne disease outbreaks in China from 1992 to 2001 national foodborne disease surveillance system

Abstract: OBJECTIVE To study the foodborne disease outbreaks in the areas covered by National Foodborne Disease Surveillance System. METHODS Total 13 provinces were included in the surveillance system, and the foodborne disease outbreaks data during 1992 to 2001 were collected. RESULTS During 1992-2001, a total of 5770 outbreaks of foodborne disease were reported. These outbreaks caused a reported 162,995 persons to become ill. Among outbreaks for which the etiology was determined, bacterial pathogens caused the largest percentage of outbreaks (38.5%) and the largest percentage of cases (50.9%). Vibrio parahaemolyticus (31.1%) accounted for the largest number of outbreaks and cases. Chemical agents caused 37.5% of outbreaks and 28.6% of cases. CONCLUSION More work needs to be done to improve the foodborne disease surveillance system.

Effects of genetic polymorphisms of metabolic enzymes on cytokinesis-block micronucleus in peripheral blood lymphocyte among coke-oven workers.

Abstract: Exploring the associations between genetic polymorphisms of metabolic enzymes and susceptibility to polycyclic aromatic hydrocarbon (PAH)–induced chromosomal damage is of great significance for understanding PAH carcinogenesis. Cytochrome P 450, glutathione S -transferase, microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, and N -acetyltransferase are PAH-metabolizing enzymes. In this study, we genotyped for the polymorphisms of these genes and assessed their effects on cytokinesis-block micronucleus (CBMN) frequencies in peripheral blood lymphocytes among 141 coke-oven workers and 66 non–coke-oven worker controls. The geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 μmol/mol creatinine, respectively ( P < 0.01). The CBMN frequency (number of micronuclei per 1,000 binucleated lymphocytes) was significantly higher in coke-oven workers (9.5 ± 6.6‰) than in the controls (4.0 ± 3.6‰; P < 0.01). Among the coke-oven workers, age was positively associated with CBMN frequency; the mEH His 113 variant genotype exhibited significantly lower CBMN frequency (8.5 ± 6.5‰) than did the Tyr 113 /Tyr 113 genotype (11.3 ± 6.4‰; P < 0.01); the low mEH activity phenotype exhibited a lower CBMN frequency (8.6 ± 6.8‰) than did the high mEH activity phenotype (13.2 ± 6.7‰; P = 0.01); the GSTP1 Val 105 /Val 105 genotype exhibited a higher CBMN frequency (15.0 ± 5.8‰) than did the GSTP1 Ile 105 /Ile 105 or Ile 105 /Val 105 genotypes (9.3 ± 6.5‰; P < 0.01); the joint effect of high mEH activity phenotype and GSTM1 null genotype on CBMN frequencies was also found. Gene-environment interactions between occupational PAH exposure and polymorphisms of mEH and/or GSTM1 were also evident. These results indicate that the mEH , GSTP1 , and GSTM1 polymorphisms may play a role in sensitivity or genetic susceptibility to the genotoxic effects of PAH exposure in the coke-oven workers.

The epidemic characteristics and preventive measures of hemorrhagic fever with syndromes in China

Abstract: OBJECTIVE To summarize and analyze the epidemic situation of hantaviruses including geographic distribution, types and prevalent intensity of epidemic areas of hantavirus for the last 30 years in China, and to discuss relative preventive measures. METHODS Collecting and analyzing the data of hantaviruses epidemics in China. RESULTS The annual number of cases of hantavirus disease rapidly increased from 3295 in 1970 to 115,804 in 1986 then sustained between 40,000 and 60,000 cases annually in the 1990's, and then decreased thereafter. The epidemic areas existed in all provinces except Qinhai and Xinjiang and there were the hospitalized cases of hantavirus disease reported in other provinces. In recent years, the prevalence of hantavirus infection had increased in some cities, and the seasonal distribution of the cases changed as well. CONCLUSION Data suggested that the new epidemic characteristics of hantaviruses had emerged in China suggesting that it was necessary to strengthen surveillance programs and to take comprehensive preventive measures for the control and prevention of hantaviruses in China.

Community-based survey of HIV transmission modes among intravenous drug users in Sichuan, China.

Abstract: Goal:The goal of this study was to investigate the prevalence and different transmission risk factors of HIV among intravenous drug users (IDUs) in the Liangshan Yizu Autonomous Region of Sichuan province, China.Methods:From November 8, 2002, to November 29, 2002, a community-based survey was conduc

The current status of schistosomiasis epidemics in China

Abstract: Objective To analyze the change of tendency on schistosomiasis epidemics in China in the last 5 years. Methods Data on schistosomiasis epidemics in the history and particularly in the last 5 years were collected. Tendency and the re-emerging status after 1998 were analyzed. Results Data in 2003 showed that in 42%, 40% and 53% of the provinces, counties and townships with epidemics, the transmission of the disease has been interrupted or controlled. The number of estimated patients of schistosomiasis and areas with snails were also reduced by 92. 74% and 73. 56%, in 2003. The annual estimated number of chronic cases was around 800 000 and 31 321. 5 hectare of snail infested areas were newly identified in recent 5 years. Among 20 national villages under longitudinal surveillance. 30%, 70% and 35% of the villages were presented a tendency of increase in the rates of human infection. bovine infection and Oncomelania snails infection, respectively. A total of 38 counties from 7 provinces have re- emerged in schistosomiasis transmission after those counties having reached criteria of transmission under control or interrupted. In 6 non-endemic counties, snails were presented, and 16 marshlands in Xan river were found with appearance of acute cases of schistosomiasis. More snail infested areas were found in Shanghai, Zhejiang, and Fujian. Both snail infested areas and newly infeeted cases were occurred in urban areas along the Yangtze River. Conclusion The tendency of increase was presented in focal areas along the Yangtze River, due to changes of environmental, ecological, societal and economic status, as well as on the forces of control.

cagA genotype and variants in Chinese Helicobacter pylori strains and relationship to gastroduodenal diseases.

Abstract: Previous studies have implicated CagA [encoded by cytotoxin-associated gene A (cagA)] in Helicobacter pylori-associated gastroduodenal pathology and distinct subgenotypes of cagA may circulate in different pathological manifestations of cagA-positive H. pylori infection. To investigate cagA genotype and variants in Chinese H. pylori strains and explore their relationship with gastroduodenal diseases, the cagA status of 82 Chinese H. pylori strains was examined and variation in size of the 3′ region of cagA in 71 of these strains was analysed by PCR. cagA was detected in 28 (100 %) of 28 strains from peptic ulcer patients, two (100 %) of two strains from gastric cancer patients, 32 (94.1 %) of 34 strains from chronic gastritis patients and 17 (94.4 %) of 18 strains from healthy volunteers. PCR products of the cagA 3′ variable region were obtained from 71 (92.2 %) of 77 Chinese H. pylori strains and could be classified into subgenotypes I, II and III, which gave PCR products of around 825, 900 and 950 bp, respectively. Subgenotype I cagA predominated in Chinese H. pylori strains (67/71), whereas subgenotype II cagA presented in two isolates from patients with chronic gastritis and subgenotype III presented in two isolates from healthy volunteers. Therefore, neither cagA nor its 3′ region variants can be used as a sole marker for the presence of particular H. pylori-related gastroduodenal diseases in the Chinese population.

Intake of soy foods and soy isoflavones by rural adult women in China.

Abstract: This study evaluated the intake of soy foods and soy isoflavones by rural adult women and potential determinant factors. Soy food consumption and information on age, education and medical history were collected on 1,188 subjects in Gansu Province and Hebei Province, China using a food frequency questionnaire to gather data on food intake over the past year. Weight and height were simultaneously measured. The results showed that 1139 (95.9%) rural women consumed soy foods in the past year. The average intake of soy foods and isoflavones was 38.7 +/- 58.2 (median = 23.5) g/d and 17.7 +/- 26.6 (median= 8.9) mg/d, respectively. Tofu accounted for the most contribution to their intake. The soy isoflavone intake ranged between 0-35 mg/day in 89.2% of subjects. Gansu women had higher intakes of soy foods and isoflavones than Henbei women (P< 0.05). Women aged 41-50 years consumed less soy foods and isoflavones than the 20-30-year olds and 31-40 year olds(P < 0.05). The intake of soy foods (P< 0.01) and isoflavones (P< 0.01) by women who experienced secondary education or above was significantly higher than illiterate women. Women without a medical history had a higher soy isoflavone intake than women with a medical history, but the difference was not statistically significant. These results suggest that the intake of soy isoflavones by Chinese rural adult women was much higher than women in Western countries. The distribution of intake was skewed to the right and varied among women in regard to region, age group and education level.

Effectiveness of personal protective measures in prevention of nosocomial transmission of severe acute respiratory syndrome

Abstract: OBJECTIVE To evaluate the effectiveness of personal protective measures of health care workers (HCWs) against severe acute respiratory syndrome (SARS). METHODS A case-control study from ten hospitals in Guangdong, with 180 non-infected and 77 infected staff members that accessed the isolation unit every day, and participated in direct first aid for severe SARS patients. All participants were surveyed about how they were using personal protective equipment (PPE), protective drugs and hygiene habits when caring for patients with SARS. Statistical analysis was done with either chi(2) or Fisher's exact test for univariate analysis, whereas we used forward stepwise selection (Waldesian) for logistic regression. RESULTS Univariate analysis showed that mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting", gargle, "membrane protection", "taking shower and changing clothing after work", "avoid from eating and drinking in ward", oseltamivir phospha tall had protective effects (P < 0.05), but stepwise logistic regression showed significant differences for mask (OR = 0.78, 95% CI: 0.60 - 0.99), goggles (OR = 0.20, 95% CI: 0.10 - 0.41) and footwear (OR = 0.58, 95% CI: 0.39 - 0.86). Analysis for linear trend in proportions showed that dose response relationship existed in mask, gown, gloves, goggles, footwear, gargle, "membrane protection" and "taking shower and changing dree after work" (P < 0.01). The attack rate of HCWs who were rescuing severe SARS patients without any PPE was 61.5% (16/26). It seemed that the more the protective measures were used, the higher the protective effect was (P < 0.001), and could reach 100% if mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting" were all used at the same time. CONCLUSIONS Nosocomial infection of SARS can be prevented effectively by precautions against droplets and personal contact. HCWs must take strict protection according to the guidance of WHO or Chinese MOH and pay attention to personal hygiene.

Detection of epidermodysplasia verruciformis-associated human papillomavirus DNA in nongenital seborrhoeic keratosis.

Abstract: Summary Background DNA of epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) has been widely detected in lesions of malignant skin tumours, benign tumours and other proliferative diseases of epithelial origin. Objectives To investigate the presence of EV-associated HPV DNA in nongenital seborrhoeic keratosis (SK) and to elucidate the prevalence of distinct HPV genotypes. Methods We investigated HPV DNA in 55 nongenital SK biopsies, which were compared with 48 normal skin biopsies (healthy controls) using a nested polymerase chain reaction (PCR) using consensus primers CP65/CP70 and CP66/CP69. The positive PCR products were retracted and used to prepare recombination clones with T-vector. Distinct clones were analysed with endonucleases, and HPV genotypes were identified by direct sequencing. Results EV-associated HPV DNA was detected in 42 of 55 (76%) nongenital SK biopsies vs. only 13 of 48 (27%) healthy controls (χ2 = 22·087; P < 0·005). The prevalence was higher in patients with more than five lesions than in those with only one lesion (P < 0·05). Ten distinct HPV genotypes were detected in the nongenital SK biopsies: HPV 20, 23, 5, renal transplant recipient (RTR) X7, HPV 17, 37, 17b, RTRX4, RTRX4b and strain SK3. HPV 20 was found in 26 of 42 (62%) positive specimens, followed by HPV 23 (11 of 42, 26%) and HPV 5 (six of 42, 14%). Existence of multiple HPV genotypes was observed in 12 of 42 (29%) positive specimens. In healthy controls, five genotypes of EV-associated HPV (HPV 20, 23, 5, 17 and RTRX4) were detected, with the same predominant genotype of HPV 20 (five of 13, 38%). Several distinct HPV genotypes were found to coexist in four of 13 (31%) positive specimens. Conclusions This study provides some evidence that EV-associated HPVs might play a part in the pathogenesis of nongenital SK.