Persistent socioeconomic and racial and ethnic disparities in pathogen burden in the United States, 1999-2014.

The disproportionate burden of prevalent, persistent pathogens among disadvantaged groups may contribute to socioeconomic and racial/ethnic disparities in long-term health. We assessed if the social patterning of pathogen burden changed over 16 years in a U.S.-representative sample. Data came from 17 660 National Health and Nutrition Examination Survey participants. Pathogen burden was quantified by summing the number of positive serologies for cytomegalovirus, herpes simplex virus-1, HSV-2, human papillomavirus and Toxoplasma gondii and dividing by the number of pathogens tested, giving a percent-seropositive for each participant. We examined sex- and age-adjusted mean pathogen burdens from 1999-2014, stratified by race/ethnicity and SES (poverty-to-income ratio (PIR); educational attainment). Those with a PIR < 1.3 had a mean pathogen burden 1.4-1.8 times those with a PIR > 3.5, with no change over time. Educational disparities were even greater and showed some evidence of increasing over time, with the mean pathogen burden among those with less than a high school education approximately twice that of those who completed more than high school. Non-Hispanic Black, Mexican American and other Hispanic participants had a mean pathogen burden 1.3-1.9 times non-Hispanic Whites. We demonstrate that socioeconomic and racial/ethnic disparities in pathogen burden have persisted across 16 years, with little evidence that the gap is closing.

Systemic Inflammation and Viral Exposure among Young Mexican American Women: Nativity-Related Differences.

BACKGROUND: Factors contributing to elevated inflammation in racial/ethnic minority populations are not well understood. We examined the association of viral exposure with C-reactive protein (CRP) in young Mexican American women. METHODS AND RESULTS: Participants (N=1,141) were currently non-pregnant women of Mexican background, aged 18-39 years, from the cross-sectional National Health and Nutrition Examination Survey (NHANES) 1999-2010. Viral exposure was defined as seropositive status for hepatitis B, and herpes simplex types 1 and 2, and classified as seronegative, seropositive for any one agent, and seropositive for 2 or 3 agents. The association of viral exposure with elevated CRP (3.01-10.00 mg/L) varied by country of birth (P=.001). Among Mexico-born women, those seropositive for 2 or 3 agents had 3.79 times (95% CI: 1.28-11.27) and those seropositive for any one agent 2.56 times (95% CI: 1.12-5.86) the odds of elevated CRP compared with seronegative women, after adjustment for age, country of birth, household density, waist circumference, glycated hemoglobin, and total cholesterol. Among US-born women, the corresponding odds were OR: .32, 95% CI: .12-.86 and OR: .71, 95% CI .43-1.17. CONCLUSIONS: In Mexico-born Mexican American women, viral exposure is associated with higher odds of elevated CRP.

Microbiology of otitis media in Indigenous Australian children: review.

OBJECTIVES: To review research addressing the polymicrobial aetiology of otitis media in Indigenous Australian children in order to identify research gaps and inform best practice in effective prevention strategies and therapeutic interventions. METHODS: Literature review. RESULTS: Studies of aspirated middle-ear fluid represented a minor component of the literature reviewed. Most studies relied upon specimens from middle-ear discharge or the nasopharynx. Culture-based middle-ear discharge studies have found that non-typeable Haemophilus influenzae and Streptococcus pneumoniae predominate, with Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pyogenes isolated in a lower proportion of samples. Alloiococcus otitidis was detected in a number of studies; however, its role in otitis media pathogenesis remains controversial. Nasopharyngeal colonisation is a risk factor for otitis media in Indigenous infants, and bacterial load of otopathogens in the nasopharynx can predict the ear state of Indigenous children. CONCLUSION: Most studies have used culture-based methods and specimens from middle-ear discharge or the nasopharynx. Findings from these studies are consistent with international literature, but reliance on culture may incorrectly characterise the microbiology of this condition. Advances in genomic technologies are now providing microbiologists with the ability to analyse the entire mixed bacterial communities ('microbiomes') of samples obtained from Indigenous children with otitis media.

Genetic, metabolic and environmental factors involved in the development of liver cirrhosis in Mexico.

Liver cirrhosis (LC) is a chronic illness caused by inflammatory responses and progressive fibrosis. Globally, the most common causes of chronic liver disease include persistent alcohol abuse, followed by viral hepatitis infections and nonalcoholic fatty liver disease. However, regardless of the etiological factors, the susceptibility and degree of liver damage may be influenced by genetic polymorphisms that are associated with distinct ethnic and cultural backgrounds. Consequently, metabolic genes are influenced by variable environmental lifestyle factors, such as diet, physical inactivity, and emotional stress, which are associated with regional differences among populations. This Topic Highlight will focus on the genetic and environmental factors that may influence the metabolism of alcohol and nutrients in the setting of distinct etiologies of liver disease. The interaction between genes and environment in the current-day admixed population, Mestizo and Native Mexican, will be described. Additionally, genes involved in immune regulation, insulin sensitivity, oxidative stress and extracellular matrix deposition may modulate the degree of severity. In conclusion, LC is a complex disease. The onset, progression, and clinical outcome of LC among the Mexican population are influenced by specific genetic and environmental factors. Among these are an admixed genome with a heterogenic distribution of European, Amerindian and African ancestry; a high score of alcohol consumption; viral infections; a hepatopathogenic diet; and a high prevalence of obesity. The variance in risk factors among populations suggests that intervention strategies directed towards the prevention and management of LC should be tailored according to such population-based features.

Fifty years of immunisation in Australia (1964-2014): the increasing opportunity to prevent diseases.

Medicine has seen dramatic changes in the last 50 years, and vaccinology is no different. Australia has made a significant contribution to world knowledge on vaccine-preventable diseases. Certain deadly diseases have disappeared or become rare in Australia following successful introduction of vaccines. As diseases become rarer, public knowledge about the diseases and their serious consequences has decreased, and concerns about potential vaccine side effects have increased. To maintain confidence in immunisations, sharing of detailed information about the vaccines and the diseases we are trying to prevent is integral to the continued success of our public health programme. Modern quality immunisation programmes need to communicate complex information to immunisation providers and also to the general community. Improving immunisation coverage rates and eliminating the gap in coverage and timeliness between Aboriginal and Torres Strait Islander peoples and non-Indigenous people has become a high priority.

Viral respiratory infections among Hajj pilgrims in 2013.

Middle East respiratory syndrome coronavirus (MERS-CoV) has emerged in the Arabian Gulf region, with its epicentre in Saudi Arabia, the host of the 'Hajj' which is the world's the largest mass gathering. Transmission of MERS-CoV at such an event could lead to its rapid worldwide dissemination. Therefore, we studied the frequency of viruses causing influenza-like illnesses (ILI) among participants in a randomised controlled trial at the Hajj 2013. We recruited 1038 pilgrims from Saudi Arabia, Australia and Qatar during the first day of Hajj and followed them closely for four days. A nasal swab was collected from each pilgrim who developed ILI. Respiratory viruses were detected using multiplex RT-PCR. ILI occurred in 112/1038 (11%) pilgrims. Their mean age was 35 years, 49 (44%) were male and 35 (31%) had received the influenza vaccine pre-Hajj. Forty two (38%) pilgrims had laboratory-confirmed viral infections; 28 (25%) rhinovirus, 5 (4%) influenza A, 2 (2%) adenovirus, 2 (2%) human coronavirus OC43/229E, 2 (2%) parainfluenza virus 3, 1 (1%) parainfluenza virus 1, and 2 (2%) dual infections. No MERS-CoV was detected in any sample. Rhinovirus was the commonest cause of ILI among Hajj pilgrims in 2013. Infection control and appropriate vaccination are necessary to prevent transmission of respiratory viruses at Hajj and other mass gatherings.

Cross-sectional study of HPV-16 infection in a population-based subsample of Hispanic adults.

OBJECTIVE: This study aimed to estimate the prevalence and correlates of seropositivity to human papillomavirus (HPV)-16 in a subsample of adults who participated in the parent study Epidemiology of Hepatitis C in the adult population of Puerto Rico (PR). SETTING: The parent study was a population-based household survey aimed to estimate the seroprevalence of hepatitis C and other viral infections (hepatitis A, hepatitis B, HIV, and herpes simplex type 2) in PR (n=1654) between 2005 and 2008. PARTICIPANTS: A subsample of the last 450 consecutive adults aged 21-64 years, recruited between February 2007 and January 2008, who participated in the parent study and agreed to participate in HPV testing. PRIMARY AND SECONDARY OUTCOME MEASURES: The samples were tested by ELISA for HPV-16 viral-like particle-specific immunoglobulin G. Information on sociodemographic, health, and lifestyle characteristics was collected. Logistic regression modelling was used to estimate the prevalence odds ratio (POR) to assess factors associated to HPV-16 seropositivity. RESULTS: Prevalence of seropositivity to HPV-16 was 11.3%. Seroprevalence was higher in women (15.8%) than men (5.6%; p=0.001). After adjusting for age and sex, ever smokers (POR 2.06, 95% CI 1.08 to 3.92) and participants with at least five lifetime sexual partners (POR 2.91, 95% CI 1.24 to 6.81) were more likely to be HPV-16 seropositive. CONCLUSIONS: HPV-16 seropositivity is similar to that reported in the USA (10.4%) for NHANES 2003-2004 participants, although different assays were used in these studies. While future studies should evaluate HPV seroprevalence using a larger population-based sample, our results highlight the need to further understand the burden of HPV infection and HPV-related malignancies in PR, population with a low vaccine uptake.

Might infection explain the higher risk of coronary heart disease in South Asians? Systematic review comparing prevalence rates with white populations in developed countries.

OBJECTIVES: South Asians in developed countries such as the UK are at comparatively high risk of coronary heart disease for reasons which are not fully understood. One unexplored hypothesis is more infections in this ethnic group. This study assessed whether the prevalence of infections among South Asians differs from that among White populations of European origin in developed countries. STUDY DESIGN: Systematic review. METHODS: Medline, Web of Science and Google Scholar databases were searched. In addition, reference lists and citations were reviewed. RESULTS: Twenty-one studies reported prevalence rates and mean antibody levels of infection with 17 different pathogens or non-specific markers of infection. Among bacterial infections, higher rates of Escherichia coli and Mycobacterium tuberculosis infection were found in South Asians. No consistent differences were found for periodontal pathogens, Helicobacter pylori, Staphylococcus aureus, Chlamydia pneumoniae and Mycobacterium avium. For viral pathogens, higher rates of hepatitis A, hepatitis B and cytomegalovirus; and lower rates of herpes simplex, hepatitis C, human immunodeficiency virus and varicella zoster virus were found among South Asians. No difference was seen in the prevalence of hepatitis G virus in South Asians. Levels of non-specific markers of infection (total immunoglobulin G, endotoxin) were higher in South Asians. CONCLUSIONS: The number of studies was small. Differences in the prevalence of specific infections were found, but the current evidence is insufficient to support or reject the hypothesis under examination. Further studies are warranted.

Successful application of a simple specimen transport method for the conduct of respiratory virus surveillance in remote Indigenous communities in Australia.

OBJECTIVE: Surveillance programs and research for acute respiratory infections in remote Aboriginal communities are complicated by difficulties in the storage and transport of frozen samples to urban laboratories for testing. This study assessed the sensitivity of a simple method for transporting respiratory samples from a remote setting for viral PCR compared with frozen specimens. METHODS: We sampled every individual who presented to a remote Aboriginal community clinic in a non-epidemic respiratory season. Two anterior nasal swabs were collected from each participant. The left nare specimen was mailed to the laboratory via routine postal services. The right nare specimen was transported frozen. Testing for 16 viruses was undertaken using real-time multiplex PCR. RESULTS: A total of 140 participants were enrolled who contributed 150 study visits. Respiratory illnesses accounted for 10% of the reasons for presentation. Sixty-one viruses were identified in 50 (33.3%) presentations for 40 (28.6%) individuals; bocavirus and rhinovirus were the most common viruses identified (14.0% and 12.6% of episodes respectively). The sensitivity for any virus detected in mailed specimens was 67.2% (95%CI 55.4, 78.9) compared to 65.6% (95%CI 53.7, 77.5) for frozen specimens. CONCLUSION: The mailing of unfrozen nasal specimens from remote communities does not compromise the viability of the specimen for viral studies.

Infectious complications in kidney transplant: a Lebanese perspective.

OBJECTIVES: Infections remain a frequent, potentially life-threatening complication of kidney transplant. SUBJECTS AND METHODS: Between 1998 and 2006, we evaluated the incidence of infections in 114 kidney transplant patients, with a 1-year follow-up. All patients received a posttransplant anti-infectious prophylaxis regimen. Induction therapy was given to 94 patients (82.4%), and maintenance immunosuppression consisted of calcineurin inhibitor (cyclosporin microemulsion or tacrolimus), together with mycophenolate mofetil and prednisone. RESULTS: In total, 56 patients (49.1%) developed a total of 95 infections up to 1-year after kidney transplant, including 46 in-hospital infections in 38 patients. Bacterial infections were the most frequent (97.8%), and were mainly urinary, followed by drain, central line catheter, and pulmonary infections. The most-frequent isolated bacteria were E. coli, followed by Klebsiella, Acinetobacter, and Pseudomonas. No viral infections were detected. Up to 1 year after discharge from the hospital, 49 infections occurred in 26 patients, of which 79.5% were bacterial; mainly urinary tract infections due to E. coli, in addition to 7 cases of cytomegalovirus, 1 herpes, and 2 cases of fungal infections. CONCLUSIONS: This is the first Lebanese study that deals with posttransplant infections in kidney transplant patients and underscores the importance of close patient monitoring and follow-up. Comparison with international data shows similar patterns.

Aboriginal health worker screening for sexually transmissible infections and blood-borne viruses in a rural Australian juvenile correctional facility.

INTRODUCTION: In Australia, Aboriginal youth are disproportionately represented in juvenile detention centres. We assessed the prevalence of sexually transmissible infections (STIs) and blood-borne viruses (BBVs) identified by an Aboriginal Health Worker (AHW)-led screening program delivered to male detainees of a rural juvenile detention centre. METHODS: A retrospective review of first screening visit data was performed. Demographic and behavioural data were collected and the prevalence of STI/BBV was assessed. RESULTS: Over a 4-year period to November 2004, 101 screens on new medium-to-long-term detainees were performed. The median age of participants was 17 years (range 14-20) and 87% were Aboriginal. Most reported multiple lifetime sexual partners (mean 14, range 0-60) and a minority had used a condom for the last episode of vaginal intercourse. Injecting drug use and non-professional tattoos or piercings were both reported by over one-third of participants, with over 80% reporting previous incarceration. One-quarter of those screened were newly diagnosed with one or more STI/BBV. The most common infection identified was urethral chlamydia (prevalence 16.3%, 95% confidence interval 10.0-25.5%), although the prevalence of newly diagnosed syphilis, hepatitis B and hepatitis C were each over 5%. Many participants remained susceptible to hepatitis B. CONCLUSION: An AHW-led STI/BBV screening program identified a large number of asymptomatic and previously undiagnosed infections in this group of young male detainees. Such an education and screening program using skilled Aboriginal staff not affiliated with the correctional system could have a substantial impact on the prevalence of STI/BBV among juvenile detainees.

Infectious burden and carotid plaque thickness: the northern Manhattan study.

BACKGROUND AND PURPOSE: The overall burden of prior infections may contribute to atherosclerosis and stroke risk. We hypothesized that serological evidence of common infections would be associated with carotid plaque thickness in a multiethnic cohort. METHODS: Antibody titers to 5 common infectious microorganisms (ie, Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpesvirus 1 and 2) were measured among stroke-free community participants and a weighted index of infectious burden was calculated based on Cox models previously derived for the association of each infection with stroke risk. High-resolution carotid duplex Doppler studies were used to assess maximum carotid plaque thickness. Weighted least squares regression was used to measure the association between infectious burden and maximum carotid plaque thickness after adjusting for other risk factors. RESULTS: Serological results for all 5 infectious organisms were available in 861 participants with maximum carotid plaque thickness measurements available (mean age, 67.2+/-9.6 years). Each individual infection was associated with stroke risk after adjusting for other risk factors. The infectious burden index (n=861) had a mean of 1.00+/-0.35 SD and a median of 1.08. Plaque was present in 52% of participants (mean, 0.90+/-1.04 mm). Infectious burden was associated with maximum carotid plaque thickness (adjusted increase in maximum carotid plaque thickness 0.09 mm; 95% CI, 0.03 to 0.15 mm per SD increase of infectious burden). CONCLUSIONS: A quantitative weighted index of infectious burden, derived from the magnitude of association of individual infections with stroke, was associated with carotid plaque thickness in this multiethnic cohort. These results lend support to the notion that past or chronic exposure to common infections, perhaps by exacerbating inflammation, contributes to atherosclerosis. Future studies are needed to confirm this hypothesis and to define optimal measures of infectious burden as a vascular risk factor.

Testing for sexually transmitted infections and blood borne viruses on admission to Western Australian prisons.

BACKGROUND: Prison populations are known to be at high risk of sexually transmitted infections (STIs) and blood borne viruses (BBVs). In accordance with State health guidelines, the Western Australian Department of Correctional Services' policy is to offer testing for STIs and BBVs to all new prison entrants. This audit was undertaken to assess the completeness and timeliness of STI and BBV testing among recent prison entrants in Western Australia, and estimate the prevalence of STIs and BBVs on admission to prison. METHODS: A retrospective audit of prison medical records was conducted among 946 individuals admitted to prison in Western Australia after the 1st January 2005, and discharged between the 1st January and 31st December 2007 inclusive. Quota sampling was used to ensure adequate sampling of females, juveniles, and individuals from regional prisons. Main outcomes of interest were the proportion of prisoners undergoing STI and BBV testing, and the prevalence of STIs and BBVs. RESULTS: Approximately half the sample underwent testing for the STIs chlamydia and gonorrhoea, and almost 40% underwent testing for at least one BBV. Completeness of chlamydia and gonorrhoea testing was significantly higher among juveniles (84.1%) compared with adults (39.8%; p < 0.001), and Aboriginal prisoners (58.3%) compared with non-Aboriginal prisoners (40.4%; p < 0.001). Completeness of BBV testing was significantly higher among adults (46.5%) compared with juveniles (15.8%; p < 0.001) and males (43.3%) compared with females (33.1%; p = 0.001). Among prisoners who underwent testing, 7.3% had a positive chlamydia test result and 24.8% had a positive hepatitis C test result. CONCLUSION: The documented coverage of STI and BBV testing among prisoners in Western Australia is not comprehensive, and varies significantly by age, gender and Aboriginality. Given the high prevalence of STIs and BBVs among prisoners, increased test coverage is required to ensure optimal use of the opportunity that prison admission presents for the treatment and control of STIs and BBVs among this high risk group.

Risk factors and viruses associated with hospitalization due to lower respiratory tract infections in Canadian Inuit children : a case-control study.

OBJECTIVES: To examine risk factors for lower respiratory tract infections (LRTI) hospital admission in the Canadian Arctic. METHODS: This was a case-control study during a 14-month period among children less than 2 years of age. Cases were admitted to the Baffin Regional Hospital in Iqaluit, Nunavut with LRTI. Controls were age matched and came from Iqaluit and 2 communities. Odds ratios (ORs) of hospital admission for LRTI were estimated through multivariate conditional logistic regression modeling for following risk factors: smoking in pregnancy, Inuit race, prematurity, adoption status, breast-feeding, overcrowding, and residing outside of Iqaluit. Viruses in nasophayngeal aspirates were sought at the time of each hospital admission. RESULTS: There were 101 age-matched cases and controls. The following risk factors were significantly associated with an increased risk of admission for LRTI (adjusted OR): smoking in pregnancy (OR = 4.0; 95% CI: 1.1-14.6), residence outside of Iqaluit (OR = 2.7; 95% CI: 1.0 -7.2), full Inuit race (OR = 3.8; 95% CI: 1.1-12.8), and overcrowding (OR = 2.5, 95% CI: 1.1- 6.1). Non-breast-fed children had a 3.6-fold risk of being admitted for LRTI (95% CI: 1.2-11.5) and non-breast-fed adopted children had a 4.4-fold increased risk (95% CI: 1.1-17.6) when compared with breast-fed, nonadopted children. Prematurity was not associated with an increased risk of admission. Viruses were identified in 88 (72.7%) of admissions, with respiratory syncytial virus being identified in the majority of admissions, 62 (51.2%). Multiple viruses were isolated in 19 (15.7%) admissions. CONCLUSIONS: Smoking during pregnancy, place of residence, Inuit race, lack of breast-feeding, and overcrowding were all independently associated with increased risk of hospital admission for LRTI among Inuit children less than 2 years of age. Future research on the role of adoption and genetics on the health of Inuit children are required.

Có vay có tra (What goes around comes around): culture, risk and vulnerability to blood-borne viruses among ethnic Vietnamese injecting drug users.

INTRODUCTION AND AIMS: Ethnic and cultural differences in vulnerability to drug-related harms have received little attention in Australia. The current study aimed to explore the influence of cultural beliefs and practices on vulnerability to blood-borne viral infections (BBVIs) among ethnic Vietnamese IDUs and to identify barriers to this group accessing health and preventive programmes. DESIGN AND METHODS: Observational fieldwork and in-depth interviews (n = 58) were conducted in South Western Sydney. Participants were recruited using a mix of snowball and theoretical sampling strategies. Open coding was used to inductively classify data into themes and data examined for regularities and variations in relationships between and within themes. RESULTS: Participants embraced pluralistic approaches to prevention, diagnosis and treatment, relying on co-existing layers of beliefs and utilising both traditional and western remedies. Four main cultural characteristics influenced vulnerability to BBVIs: trust and obligation, stoicism, the importance of 'face' and beliefs in fate. Other factors influencing injecting risk included low levels of knowledge, being in a state of withdrawal, availability of sterile injecting equipment and environmental constraints. Barriers to accessing services included stigma and discrimination, concerns in relation to confidentiality, long waiting times, resistance to pharmacotherapy treatment and language and financial barriers. DISCUSSION AND CONCLUSIONS: Results indicate a need for interventions based on culturally specific meanings and contexts of health, illness and risk. By understanding how culture impacts risk and protective behaviours among ethnic Vietnamese IDUs, clinicians and other service providers will be better equipped to meet the needs of this vulnerable group.

Improving the accuracy of Aboriginal and non-Aboriginal disease notification rates using data linkage.

BACKGROUND: Routinely collected infectious disease surveillance data provide a valuable means to monitor the health of populations. Notifiable disease surveillance systems in Australia have consistently reported high levels of completeness for the demographic data fields of age and sex, but low levels of completeness for Aboriginality data. Significant amounts of missing data associated with case notifications can introduce bias in the estimation of disease rates by population subgroups. The aim of this analysis was to evaluate the use of data linkage to improve the accuracy of estimated notification rates for sexually transmitted infections (STIs) and blood borne viruses (BBVs) in Aboriginal and non-Aboriginal groups in Western Australia. METHODS: Probabilistic methods were used to link disease notification data received in Western Australia in 2004 with core population health datasets from the established Western Australian Data Linkage System. A comparative descriptive analysis of STI and BBV notification rates according to Aboriginality was conducted based on the original and supplemented notification datasets. RESULTS: Using data linkage, the proportion of STI and BBV notifications with missing Aboriginality data was reduced by 74 per cent. Compared with excluding notifications with unknown Aboriginality data from the analysis, or apportioning notifications with unknown Aboriginality based on the proportion of cases with known Aboriginality, the rate ratios of chlamydia, syphilis and hepatitis C among Aboriginal relative to non-Aboriginal people decreased when Aboriginality data from data linkage was included. CONCLUSION: Although there is still a high incidence of STIs and BBVs in Aboriginal people, incompleteness of Aboriginality data contributes to overestimation of the risk associated with Aboriginality for these diseases. Data linkage can be effectively used to improve the accuracy of estimated disease notification rates.

Genetic polymorphisms of viral infection-associated Toll-like receptors in Chinese population.

Toll-like receptors (TLRs) play a pivotal role in an innate immunity system, which controls inflammation responses and further instructs development of adaptive immunity. We enrolled 250 Han Chinese in Taiwan screening for the single nucleotide polymorphisms (SNPs) in TLRs associated with viral infection, including TLR2, TLR3, TLR4, TLR7, TLR8, and TLR9. The 6 SNPs not hitherto identified in Chinese populations, including TLR3 1377 C>T, TLR3 -7 C>A, TLR7 Gln11Leu, TLR7 IVS1+1817 G>T, TLR8 Met1Val, and TLR8 -129 G>C, had minor allele frequencies of 38%, 23%, 22.3%, 3%, 16.0%, and 16.0%, respectively. The frequencies of 2 common SNPs, TLR9, -1486 T>C and 2848 G>A, were 28% and 44%, respectively. As compared with other ethnic populations, Chinese displayed an opposite allele frequency of TLR8 Met1Val and TLR8 -129 G>C to Caucasians and African Americans. In addition, TLR2 Arg677Try, TLR2 Arg753Gln, TLR4 Asp299Gly, and TLR4 Thr399Ile that were apparent in approximately 10% of Caucasians were not detected in Chinese. In conclusion, obvious ethnic differences in TLR polymorphisms may in part reflect the ethnic diversity of host viral susceptibility.

Racial difference in endothelial function: role of the infective burden.

There is much evidence to suggest the existence of racial differences between blacks and whites in the behaviour of endothelial function. Infective state, sustained by viral or bacterial agents, may injure the endothelial surface favouring the onset and progression of atherosclerotic process, mainly by an inflammatory mechanism. The aim of the study was to investigate endothelial function, expressed as brachial flow-mediated vasodilation (FMV), in black and white healthy subjects, along with antibody titer to cytomegalovirus, hepatitis virus (B, C), herpes virus-1 and 2, Epstein-Barr, Chlamydia pneumoniae and the expression of adhesion molecules. We enrolled 22 young (mean age 27+/-8 years) healthy subjects of black race (10 males) and 20 healthy young subjects (10 males, mean age 28+/-9 years) of white race. Total infectious burden (TIB) was defined as the number of serological positive infections. Black subjects have a reduced brachial FMV (6.9+/-3.5% versus 11.6+/-3.0%, p<0.01) and increased values of hsCRP (0.35+/-0.15 mg/dL versus 0.07+/-0.08 mg/dL, p<0.05), white cells (8578+/-1041/mmc versus 5833+/-998/mmc, p<0.01) and adhesion molecules (respectively: sVCAM-1 945+/-142 versus 779+/-93, sICAM-1 534+/-107 ng/mL versus 325+/-80 ng/mL; both p<0.01) in comparison to white subjects. The total infectious burden in black race was significantly higher than in white race (5+/-1 versus 2+/-1, p<0.01). At the univariate analysis, brachial FMV was significantly related to the levels of adhesion molecules (respectively: sVCAM-1 r=-0.49; sICAM-1 r=-0.50, both p<0.05), hsCRP (r=-0.47, p<0.05) and white blood cells (r=-0.43, p<0.05). TIB was associated with brachial FMV (r=-0.64, p<0.05), sVCAM-1 (r=0.55, p<0.05) and hsCRP (r=0.47, p<0.05). At the multivariate analysis the only predictive variables for brachial FMV were hsCRP, TIB and brachial diameter (respectively: beta=-0.49, -0.19, -0.54, all p<0.05). This study confirms that endothelial reactivity is impaired in young African black patients; moreover its behavior is strictly related to the inflammatory state and to the total infectious burden.