Implementation and evaluation of a SARI surveillance system in a tertiary hospital in Scotland in 2021/2022

OBJECTIVE

To set up and evaluate a new surveillance system for severe acute respiratory infection (SARI) in Scotland.

STUDY DESIGN

Cross-sectional study and evaluation of surveillance system.

METHODS

The SARI case definition comprised patients aged 16 years or over with an acute respiratory illness presentation requiring testing for influenza and SARS-CoV-2 and hospital admission. Data were collected from SARI cases by research nurses in one tertiary teaching hospital using a bespoke data collection tool from November 2021 to May 2022. Descriptive analyses of SARI cases were carried out. The following attributes of the surveillance system were evaluated according to Centers for Disease Control and Prevention (CDC) guidelines: stability, data quality, timeliness, positive predictive value, representativeness, simplicity, acceptability and flexibility.

RESULTS

The final surveillance dataset comprised 1163 records, with cases peaking in ISO week 50 (week ending 19/12/2021). The system produced a stable stream of surveillance data, with the proportion of SARI records with sufficient information for effective surveillance increasing from 65.4% during the first month to 87.0% over time. Similarly, the proportion where data collection was completed promptly was low initially, but increased to 50%-65% during later periods.

CONCLUSION

SARI surveillance was successfully established in one hospital, but for a national system, additional sentinel hospital sites across Scotland, with flexibility to ensure consistently high data completeness and timeliness are needed. Data collection should be automated where possible, and demands on clinicians minimised. SARI surveillance should be embedded and resourced as part of a national respiratory surveillance strategy.

End of 2022/23 Season Influenza Vaccine Effectiveness in Primary Care in Great Britain

BACKGROUND

The 2022/23 influenza season in the United Kingdom saw the return of influenza to prepandemic levels following two seasons with low influenza activity. The early season was dominated by A(H3N2), with cocirculation of A(H1N1), reaching a peak late December 2022, while influenza B circulated at low levels during the latter part of the season. From September to March 2022/23, influenza vaccines were offered, free of charge, to all aged 2-13 (and 14-15 in Scotland and Wales), adults up to 49 years of age with clinical risk conditions and adults aged 50 and above across the mainland United Kingdom.

METHODS

End-of-season adjusted vaccine effectiveness (VE) estimates against sentinel primary-care attendance for influenza-like illness, where influenza infection was laboratory confirmed, were calculated using the test negative design, adjusting for potential confounders.

METHODS

Results In the mainland United Kingdom, end-of-season VE against all laboratory-confirmed influenza for all those > 65 years of age, most of whom received adjuvanted quadrivalent vaccines, was 30% (95% CI: -6% to 54%). VE for those aged 18-64, who largely received cell-based vaccines, was 47% (95% CI: 37%-56%). Overall VE for 2-17 year olds, predominantly receiving live attenuated vaccines, was 66% (95% CI: 53%-76%).

CONCLUSION

The paper provides evidence of moderate influenza VE in 2022/23.

Interim 2023/2024 Season Influenza Vaccine Effectiveness in Primary and Secondary Care in the United Kingdom

BACKGROUND

We report 2023/2024 season interim influenza vaccine effectiveness for three studies, namely, primary care in Great Britain, hospital settings in Scotland and hospital settings in England.

METHODS

A test negative design was used to estimate vaccine effectiveness.

RESULTS

Estimated vaccine effectiveness against all influenzas ranged from 63% (95% confidence interval 46 to 75%) to 65% (41 to 79%) among children aged 2-17, from 36% (20 to 49%) to 55% (43 to 65%) among adults 18-64 and from 40% (29 to 50%) to 55% (32 to 70%) among adults aged 65 and over.

CONCLUSIONS

During a period of co-circulation of influenza A(H1N1)pdm09 and A(H3N2) in the United Kingdom, evidence for effectiveness of the influenza vaccine in both children and adults was found.

Risk of winter hospitalisation and death from acute respiratory infections in Scotland: national retrospective cohort study

OBJECTIVES

We undertook a national analysis to characterise and identify risk factors for acute respiratory infections (ARIs) resulting in hospitalisation during the winter period in Scotland.

DESIGN

A population-based retrospective cohort analysis.

SETTING

Scotland.

PARTICIPANTS

The study involved 5.4 million residents in Scotland.

MAIN OUTCOME MEASURES

Cox proportional hazard models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the association between risk factors and ARI hospitalisation.

RESULTS

Between 1 September 2022 and 31 January 2023, there were 22,284 (10.9% of 203,549 with any emergency hospitalisation) ARI hospitalisations (1759 in children and 20,525 in adults) in Scotland. Compared with the reference group of children aged 6-17 years, the risk of ARI hospitalisation was higher in children aged 3-5 years (aHR = 4.55; 95% CI: 4.11-5.04). Compared with those aged 25-29 years, the risk of ARI hospitalisation was highest among the oldest adults aged ≥80 years (aHR = 7.86; 95% CI: 7.06-8.76). Adults from more deprived areas (most deprived vs. least deprived, aHR = 1.64; 95% CI: 1.57-1.72), with existing health conditions (≥5 vs. 0 health conditions, aHR = 4.84; 95% CI: 4.53-5.18) or with history of all-cause emergency admissions (≥6 vs. 0 previous emergency admissions, aHR = 7.53; 95% CI: 5.48-10.35) were at a higher risk of ARI hospitalisations. The risk increased by the number of existing health conditions and previous emergency admission. Similar associations were seen in children.

CONCLUSIONS

Younger children, older adults, those from more deprived backgrounds and individuals with greater numbers of pre-existing conditions and previous emergency admission were at increased risk for winter hospitalisations for ARI.

Adeno-associated virus 2 infection in children with non-A-E hepatitis

An outbreak of acute hepatitis of unknown aetiology in children was reported in Scotland1 in April 2022 and has now been identified in 35 countries2. Several recent studies have suggested an association with human adenovirus with this outbreak, a virus not commonly associated with hepatitis. Here we report a detailed case-control investigation and find an association between adeno-associated virus 2 (AAV2) infection and host genetics in disease susceptibility. Using next-generation sequencing, PCR with reverse transcription, serology and in situ hybridization, we detected recent infection with AAV2 in plasma and liver samples in 26 out of 32 (81%) cases of hepatitis compared with 5 out of 74 (7%) of samples from unaffected individuals. Furthermore, AAV2 was detected within ballooned hepatocytes alongside a prominent T cell infiltrate in liver biopsy samples. In keeping with a CD4+ T-cell-mediated immune pathology, the human leukocyte antigen (HLA) class II HLA-DRB1*04:01 allele was identified in 25 out of 27 cases (93%) compared with a background frequency of 10 out of 64 (16%; P = 5.49 × 10-12). In summary, we report an outbreak of acute paediatric hepatitis associated with AAV2 infection (most likely acquired as a co-infection with human adenovirus that is usually required as a 'helper virus' to support AAV2 replication) and disease susceptibility related to HLA class II status.

1179 4.5 TONNES OF FOOD WASTED ACROSS A HOSPITAL WARD: A SERVICE EVALUATION OF DIETARY INTAKE AND FOOD WASTE

Introduction

Malnutrition is a debilitating condition in hospitalised older people. There has been limited studies exploring dietary intake and oral nutritional supplement (ONS) compliance in these people. The purpose of this service evaluation was to observe daily energy and protein intake, plate waste and ONS compliance and to report food waste at ward level.

Methods

Three-day dietary (food-only) intake and plate waste of 19 older (≥ 65 years) people on a hospital trauma and orthopaedic (T&O) ward were assessed. Patients were categorised as ‘nutritionally well’ or ‘nutritionally vulnerable’ as per British Dietetics Association’s (BDA) Nutrition and Hydration Digest criteria. Dietary intake was calculated by a Dietitian and compared with adjusted BDA standards to exclude energy and protein from drinks. Ward plate and food trolley waste were weighed after lunch and supper for five days. Thirty-three ONS from 11 patients were collected before disposal and weighed.

Results

Mean age of the patients were 84 ± 9 years (9 female, and 10 male) with the most common injury hip fracture (68.4%). Mean (standard deviation, SD) intake for ‘nutritionally well’ was 1592 (257) kcal/day and 65.7(8.5) g/day protein and ‘nutritionally vulnerable’ (n= 15) 643 (354) kcal/day and 24.8 (14.0) g/day protein. Plate waste for ‘nutritionally well’ was 4.1 (5.8)% at main meals and 1.7 (3.4)% at pudding and for ‘nutritionally vulnerable’ 53.1 (26.6)% at main meals and 38.6 (32.2)% at pudding. Compliance to ONS was 28.3 (38.8)%. The combined mealtime plate waste weighed 6.2 (1.2) kg/day and food-trolley waste 6.2 (0.9) kg/day. This equates to approximately 4526kg/year (4.5T).

Conclusions

Energy and protein intake and compliance to ONS in older T&O patients is sub-optimal. Food waste is high and urgently needs addressing. Further, interventions are warranted to improve dietary intake in hospital and to explore the acceptability of alternative ONS food/drink styles.

Epidemiology of SARS-CoV-2 during the first three waves in Scotland: a national record linkage study

BACKGROUND

The early COVID-19 pandemic in Scotland-defined as the era before widespread access to vaccination and monoclonal antibody treatment-can be characterised into three distinct waves: March-July 2020, July 2020-April 2021 and May-August 2021. Each wave was met with various societal restrictions in an effort to reduce disease transmission and associated morbidity and mortality. Understanding the epidemiology of infections during these waves can provide valuable insights into future pandemic planning.

METHODS

Scottish RT-PCR testing data reported up until 8 August 2021, the day prior to most restrictions being lifted in Scotland, were included. Demographic characteristics including age, sex and social deprivation associated with transmission, morbidity and mortality were compared across waves. A case-control analysis for each wave was then modelled to further compare risk factors associated with death over time.

RESULTS

Of the 349 904 reported cases, there were 18 099, 197 251 and 134 554 in waves 1, 2 and 3, respectively. Hospitalisations, intensive care unit admissions and deaths appeared highest in wave 2, though risk factors associated with COVID-19 death remained similar across the waves. Higher deprivation and certain comorbidities were associated with higher deaths in all waves.

CONCLUSIONS

Despite the higher number of cases reported in waves 2 and 3, case fatality rates were lower: likely a combination of improved detection of infections in younger age groups, introduction of social measures and vaccination. Higher social deprivation and comorbidities resulted in higher deaths for all waves.

POS0999 HIGHER CARDIOVASCULAR MORBIDITY SEEN IN MEN WITH LONGER DELAY TO THE DIAGNOSIS OF AXIAL SPONDYLOARTHRITIS

Background

Diagnostic delay in axial spondyloarthritis (axSpA) is a well-defined feature of the disease, despite increased awareness. Morbidity and mortality are higher in axSpA than the general population1. Much of this excess burden is due to increased comorbidity. However, the association between delayed diagnosis and increased comorbidity in this population is unknown.

Objectives

(1)Examine the relationship between delayed diagnosis and comorbidity in a large cohort of well characterised individuals with axSpA

(2)Assess the impact of sex on the relationship between diagnostic delay and comorbidity.

Methods

The Ankylosing Spondylitis Registry of Ireland (ASRI), a descriptive epidemiological study of the Irish axSpA population, provided the cohort for this study. A standardised clinical assessment was performed on each patient. Delay to diagnosis was calculated as age at diagnosis minus age at symptom onset. Comorbidities were considered as any condition present in addition to axial SpA, excluding extra-musculoskeletal manifestations (EMM). SPSS was used for statistical analysis, with appropriate tests used for normally and non-normally distributed data.

Results

Of the 913 included patients, 659 (72%) were male and mean age was 46 years (SD 13). Detailed baseline clinical and demographic characteristics are outlined in Table 1. Median delay to diagnosis was 5 (2, 12) years. Comorbidity was present in 37% (n=341) of the cohort, with hypertension the most prevalent (see Figure 1).

Table 1.

Baseline demographic and clinical characteristics

VariableAge, mean (SD)45.8 (12.6)Female, n (%)254 (27.8)Caucasian, n (%)819 (96.5)Ever Smoker, n (%)*527 (57.7)HLA-B27 positive, n (%)631 (89.9)Disease duration, median (25th,75th)17.1 (9.5, 27.8)Delay to diagnosis, median (25th, 75th)5.0 (2.0, 12.0)AAU, n (%)308 (34.4)PsO, n (%)150 (16.7)IBD, n (%)96 (10.7)Biologic use, n (%)628 (68.5)BASMI, mean (SD)3.6 (2.1)BASFI, mean (SD)3.4 (2.9)BASDAI, mean (SD)3.9 (2.4)HAQ, median (25th, 75th)0.38 (0.0, 0.9)

The median delay to diagnosis was significantly longer in those with ≥1 comorbidity compared to those with none (7 v 5 years, p<0.01). Hypertension (6 v 5 years, p=0.1) and cerebrovascular disease (10 v 5 years, p=0.03) were associated with a significantly longer delay to diagnosis, with a similar trend seen in those with hyperlipidaemia (7 v 5 years, p=0.09) and ischaemic heart disease (10 v 5 years, p=0.07). The delay to diagnosis was also longer in those that currently (7 v 5 years, p=0.03) or ever smoked (6 v 5 years, p<0.01). The delay to diagnosis was significantly longer in those with depression (9 v 5, p<0.05). The presence of EMM did not contribute to a delay to diagnosis, and there was no association with any categories of medication.

There was no significant difference in the median delay to diagnosis between females (5 v 6 years) for males. However, there were differences in the relationship between delay to diagnosis and the pattern of comorbidities between sexes. There was a significantly (p<0.05) longer delay to diagnosis in men with cerebrovascular disease (12 v 6 years), ischaemic heart disease (10 v 6 years) and diabetes (10 v 6 years), which wasn’t evident in females. Depression was associated with a longer delay to diagnosis in males (10 v 6 years, p<0.05), but not females (6 v 5 years, p=0.5).

Conclusion

Delay to diagnosis of axSpA was associated with a higher prevalence of comorbidities. This was particularly evident in men, with higher cardiovascular morbidity in those with a longer delay to diagnosis. Further research is needed to determine if shortening the delay to diagnosis would reduce the burden of cardiovascular morbidity.

References

[1]Chaudhary et al. All-Cause and Cause-Specific Mortality in Psoriatic Arthritis and Ankylosing Spondylitis: A Systematic Review and Meta-Analysis. Arthritis Care Res. 2021 Nov 17 (online).

Disclosure of Interests

None declared

POS1001 CURRENT SMOKING IS ASSOCIATED WITH LOWER RISK OF UVEITIS AND PERIPHERAL ARTHRITIS IN MALES WITH AXIAL SPONDYLOARTHRITIS

Background

The associations between smoking and extra-axial manifestations of axial spondyloarthritis (axSpA) are inadequately described. Previous observational studies have demonstrated smoking as protective against some but not other manifestations. However, the impact of sex on these associations is unknown.

Objectives

Using a large descriptive epidemiological dataset, we performed a sex-stratified analysis of the association between smoking status and extra-axial manifestations in axSpA.

Methods

This study was carried out within the framework of ASRI (Ankylosing Spondylitis Registry of Ireland), a descriptive epidemiological study of the axSpA population of Ireland. A standardised clinical assessment was performed on each patient, collecting demographic and clinical data. Smoking status was characterised as current, previous or never. The number of cigarettes per day, plus number of years smoking was also collected. Data on the following extra-axial manifestations was collected: arthritis, enthesitis, dactylitis, acute anterior uveitis (AAU), psoriasis (PsO), inflammatory bowel disease (IBD). Standardised measures of disease severity were also collected. Separate logistic regression models were used to define the association between extra-axial manifestations and smoking, controlling for potential confounders. SPSS was used for statistical analysis.

Results

Smoking data was available for 913 out of the 917 axSpA individuals with data in ASRI (mean age 46 (SD 13) years, disease duration 19 (SD 12) years, 72% male, 97% Caucasian). Twenty eight percent (n=259) were current smokers, 29% (n=268) were past smokers and 42% (n=386) were never smokers. Of the current smokers, the mean number of cigarettes per day was 12 (SD 7) and number of years smoking was 22 (SD 12). Thirty one percent had peripheral arthritis, 7% had dactylitis, 18% had enthesitis, 34% had AAU, 17% had psoriasis and 11% had IBD.

Current smokers had a significantly lower prevalence of arthritis and uveitis than past or non-smokers (see Table 1). A sex-stratified analysis was performed. There was no association between smoking status and any extra-axial manifestation in females. However, current smoking was associated with lower prevalence of arthritis in males compared to past or non-smokers (22% v 36% v 42%, p=0.002). A similar pattern was seen for uveitis, where male current smokers had a lower prevalence than non-smokers (24% v 38%, p=0.01). In contrast, psoriasis was more prevalent in men who were current smokers compared to non-smokers (18% v 12%, p=0.01), with no difference seen in females. There was no association with number of cigarettes smoked or number of years smoking.

Table 1.

Association between smoking status and extra-axial manifestations in axSpA.

AxSpA cohortCurrent smokerPast smokerNon-smokerArthritis30.9%22.4%a35.5%b33.3%bDactylitis6.7%5.5%a6.7% a7.4% aEnthesitis18.1%17.4% a16.2% a19.9% aUveitis34.3%27.4%a35.0%b38.6%bPsoriasis16.7%18.5% a19.3% a13.8% aInflammatory bowel disease10.7%9.9% a13.2% a9.5% a

Different subscript letters denote significant (p<0.05) differences between groups. Significant values highlighted in bold.

There was no association between smoking status and disease severity by subjective or objective measures, either for the cohort as a whole or by sex.

When compared to non- or ex-smokers and controlled for potential confounders including sex, age, biologic use, the association remained only between current smokers and lower risk of uveitis (OR 0.68, 95% CI 0.49 to 0.96) and arthritis (OR 0.62, 95% CI 0.43 to 0.88), in separate logistic regression models. The association between current smoking and increased prevalence of psoriasis in males did not remain significant once controlled for confounders (OR 1.10, 96% CI 0.73 to 1.65).

Conclusion

We demonstrated that current smoking is independently associated with a lower risk of uveitis and arthritis in males with axSpA, but not females. More research is needed to further investigate this paradoxical finding.

Disclosure of Interests

None declared

Investigation into cases of hepatitis of unknown aetiology among young children, Scotland, 1 January 2022 to 12 April 2022

On 31 March 2022, Public Health Scotland was alerted to five children aged 3-5 years admitted to hospital with severe hepatitis of unknown aetiology. Retrospective investigation identified eight additional cases aged 10 years and younger since 1 January 2022. Two pairs of cases have epidemiological links. Common viral hepatitis causes were excluded in those with available results. Five children were adenovirus PCR-positive. Other childhood viruses, including SARS-CoV-2, have been isolated. Investigations are ongoing, with new cases still presenting.

Use of HIV Recency Assays for HIV Incidence Estimation and Other Surveillance Use Cases: Systematic Review

BACKGROUND

HIV assays designed to detect recent infection, also known as "recency assays," are often used to estimate HIV incidence in a specific country, region, or subpopulation, alone or as part of recent infection testing algorithms (RITAs). Recently, many countries and organizations have become interested in using recency assays within case surveillance systems and routine HIV testing services to measure other indicators beyond incidence, generally referred to as "non-incidence surveillance use cases."

OBJECTIVE

This review aims to identify published evidence that can be used to validate methodological approaches to recency-based incidence estimation and non-incidence use cases. The evidence identified through this review will be used in the forthcoming technical guidance by the World Health Organization (WHO) and United Nations Programme on HIV/AIDS (UNAIDS) on the use of HIV recency assays for identification of epidemic trends, whether for HIV incidence estimation or non-incidence indicators of recency.

METHODS

To identify the best methodological and field implementation practices for the use of recency assays to estimate HIV incidence and trends in recent infections for specific populations or geographic areas, we conducted a systematic review of the literature to (1) understand the use of recency testing for surveillance in programmatic and laboratory settings, (2) review methodologies for implementing recency testing for both incidence estimation and non-incidence use cases, and (3) assess the field performance characteristics of commercially available recency assays.

RESULTS

Among the 167 documents included in the final review, 91 (54.5%) focused on assay or algorithm performance or methodological descriptions, with high-quality evidence of accurate age- and sex-disaggregated HIV incidence estimation at national or regional levels in general population settings, but not at finer geographic levels for prevention prioritization. The remaining 76 (45.5%) described the field use of incidence assays including field-derived incidence (n=45), non-incidence (n=25), and both incidence and non-incidence use cases (n=6). The field use of incidence assays included integrating RITAs into routine surveillance and assisting with molecular genetic analyses, but evidence was generally weaker or only reported on what was done, without validation data or findings related to effectiveness of using non-incidence indicators calculated through the use of recency assays as a proxy for HIV incidence.

CONCLUSIONS

HIV recency assays have been widely validated for estimating HIV incidence in age- and sex-specific populations at national and subnational regional levels; however, there is a lack of evidence validating the accuracy and effectiveness of using recency assays to identify epidemic trends in non-incidence surveillance use cases. More research is needed to validate the use of recency assays within HIV testing services, to ensure findings can be accurately interpreted to guide prioritization of public health programming.

Inferring population HIV incidence trends from surveillance data of recent HIV infection among HIV testing clients

BACKGROUND

Measuring recent HIV infections from routine surveillance systems could allow timely and granular monitoring of HIV incidence patterns. We evaluated the relationship of two recent infection indicators with alternative denominators to true incidence patterns.

METHODS

We used a mathematical model of HIV testing behaviours, calibrated to population-based surveys and HIV testing services programme data, to estimate the number of recent infections diagnosed annually from 2010 to 2019 in Côte d'Ivoire, Malawi, and Mozambique. We compared two different denominators to interpret recency data: those at risk of HIV acquisition (HIV-negative tests and recent infections) and all people testing HIV positive. Sex and age-specific longitudinal trends in both interpretations were then compared with modelled trends in HIV incidence, testing efforts and HIV positivity among HIV testing services clients.

RESULTS

Over 2010-2019, the annual proportion of the eligible population tested increased in all countries, while positivity decreased. The proportion of recent infections among those at risk of HIV acquisition decreased, similar to declines in HIV incidence among adults (≥15 years old). Conversely, the proportion of recent infections among HIV-positive tests increased. The female-to-male ratio of the proportion testing recent among those at risk was closer to 1 than the true incidence sex ratio.

CONCLUSION

The proportion of recent infections among those at risk of HIV acquisition is more indicative of HIV incidence than the proportion among HIV-positive tests. However, interpreting the observed patterns as surrogate measures for incidence patterns may still be confounded by different HIV testing rates between population groups or over time.

Updates to Spectrum's case surveillance and vital registration tool for HIV estimates and projections

INTRODUCTION

The Case Surveillance and Vital Registration (CSAVR) model within Spectrum estimates HIV incidence trends from surveillance data on numbers of new HIV diagnoses and HIV-related deaths. This article describes developments of the CSAVR tool to more flexibly model diagnosis rates over time, estimate incidence patterns by sex and age group and by key population group.

METHODS

We modelled HIV diagnosis rate trends as a mixture of three factors, including temporal and opportunistic infection components. The tool was expanded to estimate incidence rate ratios by sex and age for countries with disaggregated reporting of new HIV diagnoses and AIDS deaths, and to account for information on key populations such as men who have sex with men (MSM), males who inject drugs (MWID), female sex workers (FSW) and females who inject drugs (FWID). We used a Bayesian framework to calibrate the tool in 71 high-income or low-HIV burden countries.

RESULTS

Across countries, an estimated median 89% (interquartile range [IQR]: 78%-96%) of HIV-positive adults knew their status in 2019. Mean CD4 counts at diagnosis were stable over time, with a median of 456 cells/μl (IQR: 391-508) across countries in 2019. In European countries reporting new HIV diagnoses among key populations, median estimated proportions of males that are MSM and MWID was 1.3% (IQR: 0.9%-2.0%) and 0.56% (IQR: 0.51%-0.64%), respectively. The median estimated proportions of females that are FSW and FWID were 0.36% (IQR: 0.27%-0.45%) and 0.14 (IQR: 0.13%-0.15%), respectively. HIV incidence per 100 person-years increased among MSM, with median estimates reaching 0.43 (IQR: 0.29-1.73) in 2019, but remained stable in MWID, FSW and FWID, at around 0.12 (IQR: 0.04-1.9), 0.09 (IQR: 0.06-0.69) and 0.13% (IQR: 0.08%-0.91%) in 2019, respectively. Knowledge of HIV status among HIV-positive adults gradually increased since the early 1990s to exceed 75% in more than 75% of countries in 2019 among each key population.

CONCLUSIONS

CSAVR offers an approach to using routine surveillance and vital registration data to estimate and project trends in both HIV incidence and knowledge of HIV status.

Achieving consistency in measures of HIV-1 viral suppression across countries: derivation of an adjustment based on international antiretroviral treatment cohort data

INTRODUCTION

The third of the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets is to achieve a 90% rate of viral suppression (HIV viral load <1000 HIV-1 RNA copies/ml) in patients on antiretroviral treatment (ART) by 2020. However, some countries use different thresholds when reporting viral suppression, and there is thus a need for an adjustment to standardize estimates to the <1000 threshold. We aim to propose such an adjustment, to support consistent monitoring of progress towards the "third 90" target.

METHODS

We considered three possible distributions for viral loads in ART patients: Weibull, Pareto and reverse Weibull (imposing an upper limit but no lower limit on the log scale). The models were fitted to data on viral load distributions in ART patients in the International epidemiology Databases to Evaluate AIDS (IeDEA) collaboration (representing seven global regions) and the ART Cohort Collaboration (representing Europe), using separate random effects models for adults and children. The models were validated using data from the World Health Organization (WHO) HIV drug resistance report and the Brazilian national ART programme.

RESULTS

Models were calibrated using 921,157 adult and 37,431 paediatric viral load measurements, over 2010-2019. The Pareto and reverse Weibull models provided the best fits to the data, but for all models, the "shape" parameters for the viral load distributions differed significantly between regions. The Weibull model performed best in the validation against the WHO drug resistance survey data, while the Pareto model produced uncertainty ranges that were too narrow, relative to the validation data. Based on these analyses, we recommend using the reverse Weibull model. For example, if a country reports an 80% rate of viral suppression at <200 copies/ml, this model estimates the proportion virally suppressed at <1000 copies/ml is 88.3% (0.80^0.56 ), with uncertainty range 85.5-90.6% (0.80^0.70 -0.80^0.44 ).

CONCLUSIONS

Estimates of viral suppression can change substantially depending on the threshold used in defining viral suppression. It is, therefore, important that viral suppression rates are standardized to the same threshold for the purpose of assessing progress towards UNAIDS targets. We have proposed a simple adjustment that allows this, and this has been incorporated into UNAIDS modelling software.

Contributions of the EURO 2020 football championship events to a third wave of SARS-CoV-2 in Scotland, 11 June to 7 July 2021

Public Health Scotland used Scottish national contact tracing data to estimate the European football championship (EURO 2020) contributions to a third wave of SARS-CoV-2 infections. From 11 June to 7 July 2021, 2,632 (4%) of 63,874 SARS-CoV-2 cases self-reported attending a EURO 2020 event; 90% were male, of whom 73% were 20-39-year-olds. Most cases attended unofficial gatherings and averaged more contacts than the general population. Targeted guidance on celebrating safely in closed spaces is key.

Trends in knowledge of HIV status and efficiency of HIV testing services in sub-Saharan Africa, 2000-20: a modelling study using survey and HIV testing programme data

BACKGROUND

Monitoring knowledge of HIV status among people living with HIV is essential for an effective national HIV response. This study estimates progress and gaps in reaching the UNAIDS 2020 target of 90% knowledge of status, and the efficiency of HIV testing services in sub-Saharan Africa, where two thirds of all people living with HIV reside.

METHODS

For this modelling study, we used data from 183 population-based surveys (including more than 2·7 million participants) and national HIV testing programme reports (315 country-years) from 40 countries in sub-Saharan Africa as inputs into a mathematical model to examine trends in knowledge of status among people living with HIV, median time from HIV infection to diagnosis, HIV testing positivity, and proportion of new diagnoses among all positive tests, adjusting for retesting. We included data from 2000 to 2019, and projected results to 2020.

FINDINGS

Across sub-Saharan Africa, knowledge of status steadily increased from 5·7% (95% credible interval [CrI] 4·6-7·0) in 2000 to 84% (82-86) in 2020. 12 countries and one region, southern Africa, reached the 90% target. In 2020, knowledge of status was lower among men (79%, 95% CrI 76-81) than women (87%, 85-89) across sub-Saharan Africa. People living with HIV aged 15-24 years were the least likely to know their status (65%, 62-69), but the largest gap in terms of absolute numbers was among men aged 35-49 years, with 701 000 (95% CrI 611 000-788 000) remaining undiagnosed. As knowledge of status increased from 2000 to 2020, the median time to diagnosis decreased from 9·6 years (9·1-10) to 2·6 years (1·8-3·5), HIV testing positivity declined from 9·0% (7·7-10) to 2·8% (2·1-3·9), and the proportion of first-time diagnoses among all positive tests dropped from 89% (77-96) to 42% (30-55).

INTERPRETATION

On the path towards the next UNAIDS target of 95% diagnostic coverage by 2025, and in a context of declining positivity and yield of first-time diagnoses, disparities in knowledge of status must be addressed. Increasing knowledge of status and treatment coverage among older men could be crucial to reducing HIV incidence among women in sub-Saharan Africa, and by extension, reducing mother-to-child transmission.

FUNDING

Steinberg Fund for Interdisciplinary Global Health Research (McGill University); Canadian Institutes of Health Research; Bill & Melinda Gates Foundation; Fonds the recherche du Québec-Santé; UNAIDS; UK Medical Research Council; MRC Centre for Global Infectious Disease Analysis; UK Foreign, Commonwealth & Development Office.

Accuracy of self-reported HIV-testing history and awareness of HIV-positive status in four sub-Saharan African countries

BACKGROUND

In many countries in sub-Saharan Africa, self-reported HIV testing history and awareness of HIV-positive status from household surveys are used to estimate the percentage of people living with HIV (PLHIV) who know their HIV status. Despite widespread use, there is limited empirical information on the sensitivity of those self-reports, which can be affected by nondisclosure.

METHODS

Bayesian latent class models were used to estimate the sensitivity of self-reported HIV-testing history and awareness of HIV-positive status in four Population-based HIV Impact Assessment surveys in Eswatini, Malawi, Tanzania, and Zambia. Antiretroviral (ARV) metabolite biomarkers were used to identify persons on treatment who did not accurately report their status. For those without ARV biomarkers, we used a pooled estimate of nondisclosure among untreated persons that was 1.48 higher than those on treatment.

RESULTS

Among PLHIV, the model-estimated sensitivity of self-reported HIV-testing history ranged from 96% to 99% across surveys. The model-estimated sensitivity of self-reported awareness of HIV status varied from 91% to 97%. Nondisclosure was generally higher among men and those aged 15-24 years. Adjustments for imperfect sensitivity did not substantially influence estimates of PLHIV ever tested (difference <4%) but the proportion of PLHIV aware of their HIV-positive status was higher than the unadjusted proportion (difference <8%).

CONCLUSION

Self-reported HIV-testing histories in four Eastern and Southern African countries are generally robust although adjustment for nondisclosure increases estimated awareness of status. These findings can contribute to further refinements in methods for monitoring progress along the HIV testing and treatment cascade.

Potential effects of disruption to HIV programmes in sub-Saharan Africa caused by COVID-19: results from multiple mathematical models

Background

The COVID-19 pandemic could lead to disruptions to provision of HIV services for people living with HIV and those at risk of acquiring HIV in sub-Saharan Africa, where UNAIDS estimated that more than two-thirds of the approximately 38 million people living with HIV resided in 2018. We aimed to predict the potential effects of such disruptions on HIV-related deaths and new infections in sub-Saharan Africa.

Methods

In this modelling study, we used five well described models of HIV epidemics (Goals, Optima HIV, HIV Synthesis, an Imperial College London model, and Epidemiological MODeling software [EMOD]) to estimate the effect of various potential disruptions to HIV prevention, testing, and treatment services on HIV-related deaths and new infections in sub-Saharan Africa lasting 6 months over 1 year from April 1, 2020. We considered scenarios in which disruptions affected 20%, 50%, and 100% of the population.

Findings

A 6-month interruption of supply of antiretroviral therapy (ART) drugs across 50% of the population of people living with HIV who are on treatment would be expected to lead to a 1·63 times (median across models; range 1·39–1·87) increase in HIV-related deaths over a 1-year period compared with no disruption. In sub-Saharan Africa, this increase amounts to a median excess of HIV deaths, across all model estimates, of 296 000 (range 229 023–420 000) if such a high level of disruption occurred. Interruption of ART would increase mother-to-child transmission of HIV by approximately 1·6 times. Although an interruption in the supply of ART drugs would have the largest impact of any potential disruptions, effects of poorer clinical care due to overstretched health facilities, interruptions of supply of other drugs such as co-trimoxazole, and suspension of HIV testing would all have a substantial effect on population-level mortality (up to a 1·06 times increase in HIV-related deaths over a 1-year period due to disruptions affecting 50% of the population compared with no disruption). Interruption to condom supplies and peer education would make populations more susceptible to increases in HIV incidence, although physical distancing measures could lead to reductions in risky sexual behaviour (up to 1·19 times increase in new HIV infections over a 1-year period if 50% of people are affected).

Interpretation

During the COVID-19 pandemic, the primary priority for governments, donors, suppliers, and communities should focus on maintaining uninterrupted supply of ART drugs for people with HIV to avoid additional HIV-related deaths. The provision of other HIV prevention measures is also important to prevent any increase in HIV incidence.

Funding

Bill & Melinda Gates Foundation.

IgM in human immunity to Plasmodium falciparum malaria

Most studies on human immunity to malaria have focused on the roles of immunoglobulin G (IgG), whereas the roles of IgM remain undefined. Analyzing multiple human cohorts to assess the dynamics of malaria-specific IgM during experimentally induced and naturally acquired malaria, we identified IgM activity against blood-stage parasites. We found that merozoite-specific IgM appears rapidly in Plasmodium falciparum infection and is prominent during malaria in children and adults with lifetime exposure, together with IgG. Unexpectedly, IgM persisted for extended periods of time; we found no difference in decay of merozoite-specific IgM over time compared to that of IgG. IgM blocked merozoite invasion of red blood cells in a complement-dependent manner. IgM was also associated with significantly reduced risk of clinical malaria in a longitudinal cohort of children. These findings suggest that merozoite-specific IgM is an important functional and long-lived antibody response targeting blood-stage malaria parasites that contributes to malaria immunity.

How to achieve the global 90-90-90 target by 2020 in sub-Saharan Africa? A mathematical modelling study

OBJECTIVES

The 90-90-90 target states that by 2020, 90% of people living with HIV should be diagnosed, 90% of those diagnosed treated, and 90% of those treated virally suppressed. We assessed the actions needed in each country of sub-Saharan Africa to achieve the 90-90-90 target.

METHODS

We developed a mathematical model to assess the number of patients needing to start antiretroviral therapy (ART) between 2017 and 2020 to achieve 81% coverage by 2020 in each country, and the proportion of treated patients who are virally suppressed in four scenarios, combining two scenarios of retention (current-level or perfect), and routine viral load monitoring (current or universal coverage). We performed two separate simulations, one using observed failure rates from cohort studies, and one with considerably lower failure rates to set a theoretical lower limit.

RESULTS

Our model projected that 2.9 million people started ART in 2017 in sub-Saharan Africa. If, depending on scenario, at least 2.2-2.7 million patients continue to start ART annually, 81% ART coverage will be reached in 2020 in sub-Saharan Africa on average. In 37% of the countries, a multiple-fold increase in annual number of patients starting ART is needed. Virological suppression >90% in 2020 could be reached only in the best-case scenario assuming low probability of treatment failure, elimination of treatment interruptions, and universal routine viral load monitoring.

CONCLUSION

The 90-90-90 target is realistic in sub-Saharan Africa on average, but not necessarily in all individual countries. Each country should identify and focus on the specific gaps needing attention.

Equity of antiretroviral treatment use in high HIV burden countries: Analyses of data from nationally-representative surveys in Kenya and South Africa

OBJECTIVE

To assess changes and equity in antiretroviral therapy (ART) use in Kenya and South Africa.

METHODS

We analysed national population-based household surveys conducted in Kenya and South Africa between 2007 and 2012 for factors associated with lack of ART use among people living with HIV (PLHIV) aged 15-64 years. We considered ART use to be inequitable if significant differences in use were found between groups of PLHIV (e.g. by sex).

FINDINGS

ART use among PLHIV increased from 29.3% (95% confidence interval [CI]: 22.8-35.8) to 42.5% (95%CI: 37.4-47.7) from 2007 to 2012 in Kenya and 17.4% (95%CI: 14.2-20.9) to 30.3% (95%CI: 27.2-33.6) from 2008 to 2012 in South Africa. In 2012, factors independently associated with lack of ART use among adult Kenyan PLHIV were rural residency (adjusted odds ratio [aOR] 1.98, 95%CI: 1.23-3.18), younger age (15-24 years: aOR 4.25, 95%CI: 1.7-10.63, and 25-34 years: aOR 5.16, 95%CI: 2.73-9.74 versus 50-64 years), nondisclosure of HIV status to most recent sex partner (aOR 2.41, 95%CI: 1.27-4.57) and recent recreational drug use (aOR 2.50, 95%CI: 1.09-5.77). Among South African PLHIV in 2012, lack of ART use was significantly associated with younger age (15-24 years: aOR 4.23, 95%CI: 2.56-6.70, and 25-34 years: aOR 2.84, 95%CI: 1.73-4.67, versus 50-64 years), employment status (aOR 1.61, 95%CI: 1.16-2.23 in students versus unemployed), and recent recreational drug use (aOR 4.56, 95%CI: 1.79-11.57).

CONCLUSION

Although we found substantial increases in ART use in both countries over time, we identified areas needing improvement including among rural Kenyans, students in South Africa, and among young people and drug users in both countries.

HIV Surveillance Among Pregnant Women Attending Antenatal Clinics: Evolution and Current Direction

Since the late 1980s, human immunodeficiency virus (HIV) sentinel serosurveillance among pregnant women attending select antenatal clinics (ANCs) based on unlinked anonymous testing (UAT) has provided invaluable information for tracking HIV prevalence and trends and informing global and national HIV models in most countries with generalized HIV epidemics. However, increased coverage of HIV testing, prevention of mother-to-child transmission (PMTCT), and antiretroviral therapy has heightened ethical concerns about UAT. PMTCT programs now routinely collect demographic and HIV testing information from the same pregnant women as serosurveillance and therefore present an alternative to UAT-based ANC serosurveillance. This paper reports on the evolution and current direction of the global approach to HIV surveillance among pregnant women attending ANCs, including the transition away from traditional UAT-based serosurveillance and toward new guidance from the World Health Organization and the Joint United Nations Programme on HIV/AIDS on the implementation of surveillance among pregnant women attending ANCs based on routine PMTCT program data.

Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub⋆

We present far-infrared observations of Monoceros R2 (a giant molecular cloud at approximately 830 pc distance, containing several sites of active star formation), as observed at 70 μm, 160 μm, 250 μm, 350 μm, and 500 μm by the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on the Herschel Space Observatory as part of the Herschel imaging survey of OB young stellar objects (HOBYS) Key programme. The Herschel data are complemented by SCUBA-2 data in the submillimetre range, and WISE and Spitzer data in the mid-infrared. In addition, C18O data from the IRAM 30-m Telescope are presented, and used for kinematic information. Sources were extracted from the maps with getsources, and from the fluxes measured, spectral energy distributions were constructed, allowing measurements of source mass and dust temperature. Of 177 Herschel sources robustly detected in the region (a detection with high signal-to-noise and low axis ratio at multiple wavelengths), including protostars and starless cores, 29 are found in a filamentary hub at the centre of the region (a little over 1% of the observed area). These objects are on average smaller, more massive, and more luminous than those in the surrounding regions (which together suggest that they are at a later stage of evolution), a result that cannot be explained entirely by selection effects. These results suggest a picture in which the hub may have begun star formation at a point significantly earlier than the outer regions, possibly forming as a result of feedback from earlier star formation. Furthermore, the hub may be sustaining its star formation by accreting material from the surrounding filaments.

Monitoring HIV Treatment and the Health Sector Cascade: From Treatment Numbers to Impact

Although not originally part of the MDGs, HIV treatment has been at the center of global HIV reporting since 2003, marked by achievement of the target of 15 million people receiving treatment before 2015 and 18.2 million (16.1–19.0 million) by mid 2016. Monitoring of treatment has been strengthened with harmonized partner reporting and accountability with regular, annual reports. Beyond treatment numbers, increasingly measures of treatment adherence, retention and outcomes have been reported though with varying quality and completeness. However, with the sustainable development goals (SDGs), monitoring treatment is changing in three important ways. First, treatment monitoring is shifting from numbers to coverage and gaps in a cascade of services to achieve universal access. Secondly, this requires greater emphasis on disaggregated, individual level patient and case monitoring systems, which can better support linkage, retention and chronic, long term care. Thirdly, the prevention, testing and treatment cascade with a clear results chain, links treatment numbers to impact, in terms of reduced viral load, mortality and incidence. This agenda will require a greater contribution of routine impact evaluation alongside monitoring, with treatment seen as part of a cascade of services to ensure impact on mortality and incidence. In conclusion, the shift from monitoring treatment numbers to treatment linked to universal access to prevention, testing and treatment and impact on mortality and incidence, will be critical to monitor, evaluate, and improve HIV programs as part of the SDGs.

Genetic Diversity and Protective Efficacy of the RTS,S/AS01 Malaria Vaccine

BACKGROUND

The RTS,S/AS01 vaccine targets the circumsporozoite protein of Plasmodium falciparum and has partial protective efficacy against clinical and severe malaria disease in infants and children. We investigated whether the vaccine efficacy was specific to certain parasite genotypes at the circumsporozoite protein locus.

METHODS

We used polymerase chain reaction-based next-generation sequencing of DNA extracted from samples from 4985 participants to survey circumsporozoite protein polymorphisms. We evaluated the effect that polymorphic positions and haplotypic regions within the circumsporozoite protein had on vaccine efficacy against first episodes of clinical malaria within 1 year after vaccination.

RESULTS

In the per-protocol group of 4577 RTS,S/AS01-vaccinated participants and 2335 control-vaccinated participants who were 5 to 17 months of age, the 1-year cumulative vaccine efficacy was 50.3% (95% confidence interval [CI], 34.6 to 62.3) against clinical malaria in which parasites matched the vaccine in the entire circumsporozoite protein C-terminal (139 infections), as compared with 33.4% (95% CI, 29.3 to 37.2) against mismatched malaria (1951 infections) (P=0.04 for differential vaccine efficacy). The vaccine efficacy based on the hazard ratio was 62.7% (95% CI, 51.6 to 71.3) against matched infections versus 54.2% (95% CI, 49.9 to 58.1) against mismatched infections (P=0.06). In the group of infants 6 to 12 weeks of age, there was no evidence of differential allele-specific vaccine efficacy.

CONCLUSIONS

These results suggest that among children 5 to 17 months of age, the RTS,S vaccine has greater activity against malaria parasites with the matched circumsporozoite protein allele than against mismatched malaria. The overall vaccine efficacy in this age category will depend on the proportion of matched alleles in the local parasite population; in this trial, less than 10% of parasites had matched alleles. (Funded by the National Institutes of Health and others.).

An audit of HIV care in English prisons

Previous studies have highlighted disparities in care and outcomes in HIV-positive prisoners compared to HIV-positive individuals in the population. We audited clinical outcomes of HIV-positive prisoners accessing care in 2011. Public Health England were notified of 161 prisoners with HIV in the time period studied. Audit proformas were sent to clinics reporting prisoners to the genitourinary medicine clinic activity dataset in 2011. Thirty-two clinics responded. Data for 151 HIV-positive prisoners were reported by 12 clinics, with the other clinics not reporting any prisoners. Outcomes were compared to a previous audit, British HIV Association (BHIVA) and the National AIDS Trust guidelines. Initial CD4 counts were available for 101 patients, of which 42/101 had CD4 <350 cells/mm(3). At reception, viral load data were available for 95 patients, of which 74 were on antiretroviral therapy. Of these, 50/74 (68%) had VL <40 copies/ml. Fifty-one per cent of those on highly active antiretroviral therapy were seen in a specialist clinic less than four weeks after reception. Urgency of referral to a specialist HIV clinic was not related to CD4 or viral load. Twenty-two per cent had hepatitis C co-infection. Clinical outcomes have improved since the last audit but further opportunities exist to optimise care in prisons.

The sexual health of female sex workers compared with other women in England: analysis of cross-sectional data from genitourinary medicine clinics

Background

While female sex workers (FSWs) are assumed to be at increased risk of sexually transmitted infections (STIs), there are limited comparative data with other population groups available. Using routine STI surveillance data, we investigated differences in sexual health between FSWs and other female attendees at genitourinary medicine (GUM) clinics in England.

Methods

Demographic characteristics, STI prevalence and service usage among FSWs and other attendees in 2011 were compared using logistic regression.

Results

In 2011, 2704 FSWs made 8411 recorded visits to 131/208 GUM clinics, (primarily large, FSW-specialist centres in London). FSWs used a variety of services, however, 10% did not have an STI/HIV test at presentation. By comparison with other female attendees, FSWs travelled further for their care and had increased risk of certain STIs (eg, gonorrhoea OR_adj: 2.76, 95% CI 2.16 to 3.54, p<0.001). Migrant FSWs had better sexual health outcomes than UK-born FSWs (eg, period prevalence of chlamydia among those tested: 8.5% vs 13.5%, p<0.001) but were more likely to experience non-STI outcomes (eg, pelvic inflammatory disease OR_adj: 2.92, 95% CI 1.57 to 5.41, p<0.001).

Conclusions

FSWs in England have access to high-quality care through the GUM clinic network, but there is evidence of geographical inequality in access to these services. A minority do not appear to access STI/HIV testing through clinics, and some STIs are more prevalent among FSWs than other female attendees. Targeted interventions aimed at improving uptake of testing in FSWs should be developed, and need to be culturally sensitive to the needs of this predominantly migrant population.

The sexual health of male sex workers in England: analysis of cross-sectional data from genitourinary medicine clinics

OBJECTIVES

Male sex workers (MSW) are thought to be at increased risk of sexually transmitted infections (STI), however, limited comparative data with other groups are available. Disparities among MSWs by migrant status may also exist. Using newly available, cross-sectional surveillance data, the characteristics of MSWs and other male genitourinary medicine (GUM) clinic attendees can be investigated.

METHODS

Demographic characteristics, STI prevalence and service usage among MSWs and other male attendees between 1 January and 31 December 2011 were compared using logistic regression.

RESULTS

In 2011, 627 780 men attended GUM clinics; 488 (0.08%) were identified as MSWs. MSWs used a variety of services, however, one in seven had no HIV test at presentation. Adjusting for demographic factors and self-reported sexual orientation, MSWs had increased risk of some STIs and reinfection compared to other male attendees (eg, ORadj of gonorrhoea infection: 2.21, 95% CI 1.61 to 3.01, p<0.001, 14.1% vs 4.8% reinfected in 2011, p=0.005). Service usage did not vary between migrant and UK-born MSWs, but migrant MSWs were twice as likely to be diagnosed with chlamydia.

CONCLUSIONS

Some STIs are more prevalent and some reinfections more common among MSWs than other male attendees. A minority of MSWs do not appear to access STI/HIV testing through GUM clinics, and targeted interventions to improve uptake of testing in MSWs should be developed. Service usage and sexual health of MSWs does not appear to vary greatly by migrant status, though the increased risk of chlamydia infection among migrant MSWs should be investigated further.

Trends and associations of Trichomonas vaginalis infection in men and women with genital discharge syndromes in Johannesburg, South Africa

OBJECTIVES

To better understand the epidemiology of Trichomonas vaginalis infection, we investigated the association between T vaginalis and demographic, clinical, microbiological and behavioural characteristics of patients presenting with genital discharges to a primary healthcare clinic in Johannesburg, South Africa.

METHODS

During six annual surveys (2007-2012), 1218 cases of male urethral discharge syndrome and 1232 cases of vaginal discharge syndrome were consecutively recruited. Diagnostic methods included nucleic acid amplification (Neisseria gonorrhoeae, Chlamydia trachomatis, T vaginalis and Mycoplasma genitalium), microscopy (bacterial vaginosis and Candida) and serology (Treponema pallidum, herpes simplex virus type 2 (HSV-2) and HIV). Logistic regression analyses and χ2 tests were used to identify predictors of T vaginalis infection.

RESULTS

The prevalence of T vaginalis decreased from 2007 to 2012 (men from 13.4% to 4.8%; women from 33.8 to 23.1%). Overall, 74 (6.1%) men and 291 (23.6%) women were T vaginalis positive, with the highest prevalence in those aged ≥40 years (men 13.6%; women 30.9%). T vaginalis infection occurred more often in pregnant women (adjusted OR (aOR) 2.67; 95% CI 1.29 to 5.54) and in women with serological evidence of T pallidum (aOR 1.63; 95% CI 1.08 to 2.45) or HSV-2 infections (aOR 1.75; 95% CI 1.16 to 2.64). T vaginalis infection occurred less often in men with coexistent gonorrhoea (aOR 0.35; 95% CI 0.21 to 0.57) and in women with either bacterial vaginosis (aOR 0.60; 95% CI 0.44 to 0.82) or Candida morphotypes (OR 0.61; 95% CI 0.43 to 0.86).

CONCLUSIONS

Although the prevalence of T vaginalis infection has decreased over time, it remains an important cause of genital discharge in South Africa, particularly in older patients and pregnant women.

The clinical effectiveness and cost-effectiveness of primary stroke prevention in children with sickle cell disease: a systematic review and economic evaluation

BACKGROUND

Sickle cell disease (SCD) is a recessive genetic blood disorder, caused by a mutation in the β-globin gene. For children with SCD, the risk of stroke is estimated to be up to 250 times higher than in the general childhood population. Transcranial Doppler (TCD) ultrasonography is a non-invasive technique which measures local blood velocity in the proximal portions of large intracranial arteries. Screening with TCD ultrasonography identifies individuals with high cerebral blood velocity; these children are at the highest risk of stroke. A number of primary stroke prevention strategies are currently used in clinical practice in the UK including blood transfusion, treatment with hydroxycarbamide and bone marrow transplantation (BMT). No reviews have yet assessed the clinical effectiveness and cost effectiveness of primary stroke prevention strategies in children with SCD identified to be at high risk of stroke using TCD ultrasonography.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of primary stroke prevention treatments for children with SCD who are identified (using TCD ultrasonography) to be at high risk of stroke.

DATA SOURCES

Electronic databases were searched from inception up to May 2011, including the Cochrane Database of Systematic Reviews (CDSR), the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects (DARE), EMBASE, the Health Technology Assessment (HTA) database, ISI Web of Science Proceedings, ISI Web of Science Citation Index, the NHS Economic Evaluation Database (NHS EED) and MEDLINE.

REVIEW METHODS

The assessment was conducted according to accepted procedures for conducting and reporting systematic reviews and economic evaluations. A de novo Markov model was developed to determine the cost-effectiveness of TCD ultrasonography and blood transfusion, where clinically appropriate, in patients with SCD.

RESULTS

Two randomised controlled trials met the inclusion criteria involving a study population of 209 participants. One compared blood transfusion with standard care for children who are identified as being at high risk of stroke using TCD ultrasonography. In this trial, one patient in the transfusion group had a stroke (1/63) compared with 11 children in the standard care group (11/67). The other trial assessed the impact of halting chronic transfusion in patients with SCD. Sixteen patients in the transfusion-halted group had an event (16/41) (two patients experienced stroke and 14 reverted to abnormal TCD velocity); there were no events in the continued-transfusion group (0/38). No meta-analyses of these trials were undertaken. No relevant economic evaluations were identified for inclusion in the review. The de novo modelling suggests that blood transfusions plus TCD scans (compared with just TCD scans) for patients with SCD at high risk of stroke, aged ≥ 2 years, may be good value for money. The intervention has an incremental cost-effectiveness ratio of £24,075 per quality-adjusted life-year gained, and helps avoid 68 strokes over the lifetime of a population of 1000 patients. The intervention costs an additional £13,751 per patient and generates 0.6 extra years of life in full health per patient. The data available for the economic analysis are limited. Sensitivity analyses and validation against existing data and expert opinion provide some reassurance that the conclusion of the model is reliable but further research is required to validate these findings.

LIMITATIONS

The main limitations relate to the availability of published clinical data; no completed randomised controlled trials were identified which evaluated the efficacy of either BMT or hydroxycarbamide for primary stroke prevention. Both the clinical and cost data available for use in the economic analysis are limited. Sensitivity analyses and validation against existing data and expert opinion provide some reassurance that the conclusions of the model are reliable, but further research is required to validate these findings.

CONCLUSIONS

The use of TCD ultrasonography to identify children at high risk of stroke, and treating these children with prophylactic blood transfusions, appears to be both clinically effective and cost-effective compared with TCD ultrasonography only. However, given the limitations in the data available, further research is required to verify this conclusion. Several research recommendations can be proposed from this review. Clinically, more research is needed to assess the effects and optimal duration of long-term blood transfusion and the potential role of hydroxycarbamide in primary stroke prevention. From an economics perspective, further research is required to generate more robust data on which to base estimates of cost-effectiveness or against which model outputs can be calibrated. More data are required to explain how utility weights vary with age, transfusions and strokes. Research is also needed around the cost of paediatric stroke in the UK.

STUDY REGISTRATION

PROSPERO CRD42011001496.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Rapid increase in gonorrhoea and syphilis diagnoses in England in 2011

There has been a rapid rise in the number of gonorrhoea and syphilis diagnoses in England during 2011, an increase of 25% and 10% respectively. Large increases of both gonorrhoea (61%) and syphilis (28%) were observed among men who have sex with men. Although these rises can partly be attributed to increased testing, ongoing high-levels of unsafe sexual behaviour probably contributed to the rise. The rise in gonorrhoea rates is worrying in an era of decreased susceptibility to treatments.

Rapid increase in gonorrhoea and syphilis diagnoses in England in 2011

There has been a rapid rise in the number of gonorrhoea and syphilis diagnoses in England during 2011, an increase of 25% and 10% respectively. Large increases of both gonorrhoea (61%) and syphilis (28%) were observed among men who have sex with men. Although these rises can partly be attributed to increased testing, ongoing high-levels of unsafe sexual behaviour probably contributed to the rise. The rise in gonorrhoea rates is worrying in an era of decreased susceptibility to treatments.

Allele-specific antibodies to Plasmodium falciparum merozoite surface protein-2 and protection against clinical malaria

IgG and IgG3 antibodies to merozoite surface protein-2 (MSP-2) of Plasmodium falciparum have been associated with protection from clinical malaria in independent studies. We determined whether this protection was allele-specific by testing whether children who developed clinical malaria lacked IgG/IgG3 antibodies specific to the dominant msp2 parasite genotypes detected during clinical episodes. We analysed pre-existing IgG and IgG1/IgG3 antibodies to antigens representing the major dimorphic types of MSP-2 by ELISA. We used quantitative real-time PCR to determine the dominant msp2 alleles in parasites detected in clinical episodes. Over half (55%, 80/146) of infections contained both allelic types. Single or dominant IC1- and FC27-like alleles were detected in 46% and 42% of infections respectively, and both types were equally dominant in 12%. High levels of IgG/IgG3 antibodies to the FC27-like antigen were not significantly associated with a lower likelihood of clinical episodes caused by parasites bearing FC27-like compared to IC1-like alleles, and vice versa for IgG/IgG3 antibodies to the IC1-like antigen. These findings were supported by competition ELISAs which demonstrated the presence of IgG antibodies to allele-specific epitopes within both antigens. Thus, even for this well-studied antigen, the importance of an allele-specific component of naturally acquired protective immunity to malaria remains to be confirmed.