Measles viral load may reflect SSPE disease progression

Subacute sclerosing panencephalitis (SSPE) is a rare, slowly progressive neurological disorder caused by the persistent infection with measles virus (MV). Despite much research into SSPE, its pathology remains obscure. We examined autopsy tissues of eight SSPE patients by real time quantitative PCR, immunohistochemistry and immunoblotting to determine viral load. MV N, M and H gene RNA could be detected in the central nervous system (CNS) of all patients and in two non-CNS tissues of one patient. The viral burden between patients differed up to four-fold by quantitative PCR and corresponded with detection of MV protein. The level of both viral RNA and antigen in the brain may correlate with disease progression

Use of Saliva for Early Dengue Diagnosis

The importance of laboratory diagnosis of dengue cannot be undermined. In recent years, many dengue diagnostic tools have become available for various stages of the disease, but the one limitation is that they require blood as a specimen for testing. In many incidences, phlebotomy in needle-phobic febrile individuals, especially children, can be challenging, and the tendency to forgo a dengue blood test is high. To circumvent this, we decided to work toward a saliva-based assay (antigen-capture anti-DENV IgA ELISA, ACA-ELISA) that has the necessary sensitivity and specificity to detect dengue early. Overall sensitivity of the ACA-ELISA, when tested on saliva collected from dengue-confirmed patients (EDEN study) at three time points, was 70% in the first 3 days after fever onset and 93% between 4 to 8 days after fever onset. In patients with secondary dengue infections, salivary IgA was detected on the first day of fever onset in all the dengue confirmed patients. This demonstrates the utility of saliva in the ACA-ELISA for early dengue diagnostics. This technique is easy to perform, cost effective, and is especially useful in dengue endemic countries

Oral fluid collection by post--a pilot study of two approaches.

This pilot study aimed to assess the feasibility of the postal collection of oral fluid samples for surveillance purposes and the effect of two different approaches on the response rates. This cross-sectional, antibody prevalence study collected oral fluid samples and questionnaire data from randomly selected individuals, aged under 45 y, through the post. The individuals were recruited from four general practice registers. In a one stage approach patients were sent the oral fluid kit with the initial invitation letter. In a two stage approach the kits were sent out after written consent had been received. There was little difference in the overall response rates between the two approaches (38% two stage and 41% one stage), though the response rate for the one stage approach was 10% higher in the under-20-y-olds in practices from areas of greater deprivation. The low response partly reflected poor uptake in young adults who may need to be approached through more targeted surveys. In the other age groups additional reminders could prove a cost-effective way of increasing the response rate further

A population-based seroprevalence study of hepatitis A virus using oral fluid in England and Wales.

Population-based seroprevalence studies provide important data on susceptible groups and the potential for future outbreaks. However, the invasive nature of serum collection has limited studies. This paper describes the first postal population-based survey using noninvasive oral fluid technology to collect antibody prevalence data in conjunction with extensive risk factor data to assess the distribution of immunity to common viral infections in England and Wales. These results pertain to hepatitis A virus (HAV). Approximately 5,500 oral fluid samples were collected between August 2001 and May 2002, as well as individual risk factor data through a questionnaire, from persons aged less than 45 years randomly sampled from general practices countrywide. Samples were tested for immunoglobulin G-specific antibody marking a past infection or immunity to HAV using an antibody-capture enzyme-linked immunosorbent assay. The age-specific HAV seroprevalences indicated a low incidence of infection (overall seroprevalence of 18.9% (95% confidence interval: 17.0, 20.9) and of 9.2% (95% confidence interval: 7.1, 11.3) after the exclusion of vaccinees). Vaccination proved the most important determinant of seropositivity. Ethnic minority groups were underrepresented, and adjustment increased the overall prevalence to 20.1% and to 12.1% in unvaccinated individuals. The availability of comprehensive risk factor data allowed the description of two risk profiles related to natural infection and vaccination

Pre-and post-vaccine measles antibody status in infants using serum and oral-fluid testing: an evaluation of routine immunization in Addis Ababa, Ethiopia

Despite the use of measles vaccine, measles incidence in Ethiopia remains a serious public health concern. Progress towards the control of measles requires a national capacity to measure programme effectiveness. This includes evaluation of vaccine effectiveness in infants attending the routine immunization. Objective: To evaluate the effectiveness of the measles routine immunization activities in Addis Ababa. Methods: This study evaluated pre- and post-vaccine antibodies in children attending for routine measles immunization in Addis Ababa. Infants who presented to 3 health centres between September-November, 1998 for routine measles vaccination were enrolled in the study. In total 296 infants (median age 9 months) provided blood and oral-fluid samples, of which 230 (77%) returned to provide post vaccine samples (median interval of 15 days). Screening of sera was undertaken using commercial indirect ELISA kits, and of oral fluids using an in-house IgM-capture ELISA. Results: Pre-vaccination serology showed 1.4% IgM positive, 2.0% IgG positive, and 97.0% seronegative. Post-vaccination seroprevalence of IgM and IgG was 91.3% and 85.0%, respectively, and 92.9% overall. The seroconversion rate was 92.6% (95%CI 88.2-95.7). Based on oral fluid results, 87.3% (95% CI 82.0-91.4) of children showed specific IgM antibody conversion. Conclusion: These results are in support of the recommended age for measles vaccination in Addis Ababa, and show the merit of oral-fluid IgM screening as a non-invasive alternative to blood for assessing vaccine effectiveness. Ethiop.J.Health Dev. 2003; 17(3): 149-15

Institutional risk factors for outbreaks of nosocomial gastroenteritis: survival analysis of a cohort of hospital units in South-west England, 2002-2003.

Nosocomial outbreaks of gastroenteritis are a major burden on hospital inpatient services, costing an estimated pound115 million annually to the English National Health Service. We actively followed-up 171 inpatient units from four major acute hospitals and 11 community hospitals in South-west England for one year. Outbreaks of gastroenteritis were ascertained through an active surveillance network using standard clinical definitions. Survival analysis Cox regression models using an outbreak of gastroenteritis as the endpoint were fitted to identify institutional and operational attributes related to increased outbreak rates at the level of the care unit. Greater number of beds in unit [hazard ratio (HR) 1.22 (per 10 additional beds), 95% confidence intervals (CI) 0.96-1.55] was associated with increased hazard, as were geriatric (HR 2.6, 95%CI 1.6-4.3) and general medical (HR 1.7, 95%CI 1.1-2.6) care units. The average length of stay on a unit was inversely associated with outbreak incidence [HR=0.89 (per additional week of stay), 95%CI 0.80-0.99]. Larger care units and those with higher throughput have increased rates of gastroenteritis outbreaks. These results should guide infection control policy and support the design of hospitals with smaller care units

A randomised placebo-controlled trial to explore the effect of suppressive therapy with acyclovir on genital shedding of HIV-1 and herpes simplex virus type 2 among Zimbabwean sex workers.

OBJECTIVES: To determine the effect of daily acyclovir on genital shedding of HIV-1 and herpes simplex virus type 2 (HSV-2) in a randomised placebo-controlled trial among rural Zimbabwean sex workers. METHODS: 214 women were recruited and tested for HIV-1 and HSV-2 antibodies, HIV plasma viral load, CD4 lymphocyte count and genital swabs for qualitative detection of HIV-1 and HSV-2 genital shedding. Women were randomly assigned to acyclovir 400 mg twice a day for 12 weeks or matching placebo and were followed weekly to detect HIV-1 or HSV-2 genital shedding. Shedding analyses were only undertaken on 125 women co-infected with HSV-2 and HIV-1. Data were analysed using logistic regression, with random effects modelling used to account for repeated measurements on the same women. RESULTS: All women were randomly assigned to acyclovir or placebo; 125 of whom were co-infected with HIV-1 and HSV-2. 69 women were randomly assigned to acyclovir and 56 to placebo. Although twice daily acyclovir reduced rates of HSV-2 genital shedding, (adjusted odds ratio (AOR) 0.24; 95% CI 0.12 to 0.48; less than p<0.001), it had no effect on the proportion of visits at which HIV-1 shedding was detected (AOR 1.08; 95% CI 0.48 to 2.42; p = 0.9). Adherence varied between participants but even when adherence was high (as determined by pill count and extent of HSV-2 suppression) HIV-1 shedding was not reduced. CONCLUSION: Among these HIV-1 and HSV-2-seropositive women, suppressive acyclovir therapy had no effect on the rate of HIV genital shedding despite a reduction in genital HSV-2. Treatment adherence and its measurement clearly affect the interpretation of these results

The seroepidemiology of varicella zoster virus among pregnant Bangladeshi and white British women in the London Borough of Tower Hamlets, UK

We investigated the comparative seroepidemiology of varicella zoster virus (VZV) in pregnant women of two ethnic groups, white British and Bangladeshi, living in an inner city area of London, United Kingdom. Women aged 16-45 years were recruited from antenatal clinics of the Royal London Hospital in the Borough of Tower Hamlets. Complete data were obtained from 275 white British and 765 Bangladeshi women. VZV antibody prevalence was 93.1% (95% CI 89.4-95.8) and 86.0% (95% CI 83.3-88.4) respectively. Women who were born in Bangladesh and lived there at least until the age of 15 years had the lowest odds of being immune (OR 0.37, 95% CI 0.22-0.63). This implies they will have an increased risk of varicella during pregnancy. Women arriving in the United Kingdom in adulthood should be screened routinely during pregnancy and vaccination offered postpartum if they are susceptible