Oral Manifestations of Ethnic Chinese HIV- infected Adults on HAART

The dawn of highly active anti-retroviral therapy (HAART) has revolutionized the prognostic outcome of patients infected with HIV. Consequently, type and prevalence of oral manifestations have been reduced significantly with the advent of HAART. OBJECTIVE: to identify the types and prevalence of oral lesions among HIV infected individuals in Hong Kong, on HAART. METHODS: 101 individuals with HIV infection attending the Queen Elizabeth Hospital, Hong Kong were selected. Oral lesions were diagnosed using ECC-clearing house-classification and WHO criteria by a single, calibrated examiner. Data on the type of oral lesion present, CD4+ lymphocyte count, HIV plasma load and past history of oral lesions and the duration of HAART was ...postprin

Identification of differential pharyngeal cytokine profiles during HIV infection

Poster Presentation: no. P90BACKGROUND: Significantly higher pharyngeal shedding of Epstein-Barr virus (EBV) is observed during HIV infection. Increased EBV shedding in pharynx is not affected even during highly active antiretroviral theyrapy (HAART). EBV positive monocyte populations have been shown to carry EBV to pharyngeal mucosa. Human cytokine profiles are often altered to facilitate herpes virus infection. Thus pharyngeal cytokine profiles may influence EBV reactivation and shedding during HIV infection. Our objective was to compare 37 pharyngeal cytokine profiles of HIV-seropositive patients who were or were not receiving HAART therapy …published_or_final_versio

Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels in Nigeria, 2015

Evidence of current and past Middle East respiratory syndrome coronavirus (MERS-CoV) infection in dromedary camels slaughtered at an abattoir in Kano, Nigeria in January 2015, was sought by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and serology. MERS-CoV RNA was detected in 14 (11%) of 132 nasal swabs and antibody in 126 (96%) of 131 serum samples. Phylogenetic analyses demonstrate that the viruses in Nigeria are genetically distinct from those reported in the Arabian peninsula.published_or_final_versio

Variability in the immunogenicity of inactivated seasonal influenza vaccine in children due to age and recent previous influenza vaccination

Poster Session: VaccinesBackground: Annual receipt of trivalent inactivated influenza (TIV) vaccination is recommended for school-age children in some countries. However, there is little data on the variability of the immunogenicity of influenza vaccination in children and how this is affected by their age and recent influenza vaccination history. Materials and Methods: We used data on children in a Hong Kong community-based study who were randomized to receive TIV before the 2009-2010 influenza season. Antibody titers against seasonal and pandemic A(H1N1), seasonal A(H3N2), and two B influenza viruses (B/Brisbane and B/Florida) were measured by hemagglutination inhibition immediately before and 1 month after vaccination (Cowling et al. Clin Infect Dis. 2012). Multivariate regression models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titers following vaccination and update previous findings by considering the correlation between virus strains (Ng et al. Pediatr Infect Dis J. 2013). Results: In 452 subjects, statistically significant rises in the geometric means of all antibody titers were observed, with those against the virus strains included in the TIV rising by geometric means of 7.95 to 13.36; those against pandemic A(H1N1) and B/Florida rose by 1.47 and 4.21, respectively. Geometric standard deviations were between 3.76 and 8.41 around the geometric means, with pandemic A(H1N1) showing the least variability in rises. The most closely correlated titer increases were those for the two influenza B viruses, while increases in pandemic A(H1N1) titers were unrelated to any other titer. Being vaccinated in either of the two previous years significantly reduced the increase in seasonal A(H1N1) and A(H3N2) antibody titers, while among children not vaccinated in the previous 2 years, those aged > 9 years experienced significantly higher increases in the influenza B titers than those aged 6-8 years. Conclusions: Increases in antibody titers following vaccination can vary depending on age and vaccination history. Results from our study suggest that humoral antibody response to TIV may be lower in children receiving repeated vaccination, but receipt of TIV induced seroprotection in most subjects.published_or_final_versio

Interpreting Seroepidemiologic Studies of Influenza in a Context of Nonbracketing Sera

Background: In influenza epidemiology, analysis of paired sera collected from people before and after influenza seasons has been used for decades to study the cumulative incidence of influenza virus infections in populations. However, interpretation becomes challenging when sera are collected after the start or before the end of an epidemic, and do not neatly bracket the epidemic. Methods: Serum samples were collected longitudinally in a community-based study. Most participants provided their first serum after the start of circulation of influenza A(H1N1)pdm09 virus in 2009. We developed a Bayesian hierarchical model to correct for nonbracketing sera and estimate the cumulative incidence of infection from the serological data and surveillance data in Hong Kong. Results: We analyzed 4,843 sera from 2,097 unvaccinated participants in the study, collected from April 2009 to December 2010. After accounting for nonbracketing, we estimated that the cumulative incidence of H1N1pdm09 virus infection was 45% (95% credible interval [CI] = 40%, 49%), 17% (95% CI = 13%, 20%), and 11% (95% CI = 6%, 18%) for children ages 0–18 years, adults 19–50 years, and older adults >50 years, respectively. Including all available data substantially increased precision compared with a simpler analysis based only on sera collected at 6-month intervals in a subset of participants. Conclusions: We developed a framework for the analysis of antibody titers that accounted for the timing of sera collection with respect to influenza activity and permitted robust estimation of the cumulative incidence of infection during an epidemic.postprin

Determinants of serum 25-hydroxyvitamin D in Hong Kong

Vitamin D plays an important role in skeletal health throughout life. Some studies have hypothesised that vitamin D may reduce the risk of other diseases. Our study aimed to estimate age-specific and sex-specific serum 25-hydroxyvitamin D (25(OH)D) status and to identify the determinants of serum 25(OH)D status in Hong Kong, a subtropical city in southern China. In 2009-2010, households in Hong Kong were followed up to identify acute respiratory illnesses, and sera from 2694 subjects were collected in three to four different study phases to permit measurement of 25(OH)D levels at different times of the year. A questionnaire survey on diet and lifestyle was conducted among children, with simultaneous serum collection in April and May 2010. The mean of serum 25(OH)D levels in age groups ranged from 39 to 63 nmol/l throughout the year with the mean values in all age groups in spring below 50 nmol/l. Children aged 6-17 years, and girls and women had significantly lower serum 25(OH)D levels than adults, and boys and men, respectively (all P< 0·001). We estimated that serum 25(OH)D levels in Hong Kong followed a lagged pattern relative to climatic season by 5 weeks with lowest observed levels in early spring (March). For children aged 6-17 years, reporting a suntan, having at least 1 servings of fish/week and having at least 1 serving of eggs/week were independently associated with higher serum 25(OH)D levels. Adequate sunlight exposure and increased intake of dietary vitamin D could improve vitamin D status, especially for children and females in the winter and spring.postprin

Longitudinal study of middle east respiratory syndrome coronavirus infection in dromedary camel herds in Saudi Arabia, 2014–2015

Two herds of dromedary camels were longitudinally sampled with nasal and rectal swabs and serum, between September 2014 and May 2015, and the samples were tested for Middle East Respiratory Syndrome (MERS) coronavirus RNA and antibodies. Evidence of MERS-CoV infection was confirmed in one herd on the basis of detection of virus RNA in nasal swabs from three camels and significant increases in the antibody titers from three others. The three viruses were genetically identical, thus indicating introduction of a single virus into this herd. There was evidence of reinfection of camels that were previously seropositive, thus suggesting that prior infection does not provide complete immunity from reinfection, a finding that is relevant to camel vaccination strategies as a means to prevent zoonotic transmission.published_or_final_versio

Inferring Influenza Infection Attack Rate from Seroprevalence Data

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MERS-CoV in Arabian camels in Africa and Central Asia

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) causing infections in humans is genetically indistinguishable from the virus found in Arabian camels (dromedaries) in the Middle East. Although no primary human case of MERS was reported outside the Arabian Peninsula, camel populations in Africa are known to have high prevalence of antibodies against MERS-CoV. We carried out surveillance for MERS-CoV in dromedaries in Africa and Central Asia. By MERS-CoV spike pseudoparticle neutralization assay we confirmed that camel serum samples from African countries have high prevalence of MERS-CoV antibodies. Using RT-qPCR we detected MERS-CoV positives in camel nasal swabs from all different African countries from which samples were collected. However, dromedary serum and swab samples from Kazakhstan in Central Asia were negative for MERS-CoV by these assays. Phylogenetic analysis of the spike gene revealed that MERS-CoVs from Africa formed a cluster closely related to but distinct from the viruses from the Arabian Peninsula. Results from this study suggest that MERS-CoV is actively circulating in dromedary populations in Africa and the virus in Africa is phylogenetically distinct from that in the Middle East.published_or_final_versio