̽��ֱ�� of Cambridge - Anne Presanis

Fewer than one in 20 people living with HIV in England expected to be unaware of status by 2025

cjb250 — Fri, 24 Sep 2021 07:49:11 +0000

In 2014, UNAIDS set an ambitious target of 90-90-90 by 2020 – that is, 90% of all people living with HIV will know their HIV status; 90% of all people with diagnosed HIV infection will receive sustained antiretroviral therapy; and 90% of all people receiving antiretroviral therapy will have viral suppression.

According to the Cambridge and PHE team, in 2019 there were an estimated 105,200 people living with HIV in the UK, of whom 94% were aware of their HIV status. In addition, 98% of those living with diagnosed HIV were on treatment, and 97% of these were virally suppressed. In other words, England had already reached the UNAIDS goals.

In a publication today in ̽��ֱ��Lancet Public Health, the researchers extended their analysis of evidence from multiple surveillance, demographic, and survey datasets relevant to HIV in England from estimating HIV prevalence in a single year to estimating the trends over time in HIV prevalence. Trends in the number of people living with HIV, the proportion of people unaware of their HIV infection, and the corresponding prevalence of undiagnosed HIV are reported.

According to their analysis, the estimated number of people in England living with HIV aged 15-74 years who were unaware of their infection halved from 11,600 in 2013 to 5,900 in 2019, with a corresponding fall in prevalence from 0.29 to 0.14 per 1,000 people.

At the same time, the increase in the number of people living with diagnosed HIV resulted in the total number of people living with HIV rising from 83,500 to 92,800 over the same period. ̽��ֱ��percentage of people living with HIV whose infection was diagnosed therefore steadily increased from 86% in 2013 to 94% in 2019, reaching the UNAIDS target in 2016 – and even earlier, in 2013, for Black African heterosexuals.

Professor Daniela De Angelis from the MRC Biostatistics Unit, the study’s senior author, said: “Overall, we see a positive picture for the HIV epidemic in England, with a dramatic fall in the number of people living with undiagnosed HIV. We estimate we are already several years ahead of the UNAIDS 2020 goals and are on target to reach 95% diagnosed by 2025 and to eliminate HIV infections by 2030.

Dr Anne Presanis from the MRC Biostatistics Unit added: “Examined more closely, the situation is not as positive for everyone. We estimate that areas of England outside London have not seen as steep a decrease in undiagnosed HIV prevalence as in London, and there is evidence of missed opportunities to diagnose HIV infections among some population subgroups.”

In England, gay, bisexual, and other men who have sex with men, and Black African heterosexuals remain disproportionately affected by HIV, with considerably higher undiagnosed HIV prevalence per population in 2019 than heterosexuals in other ethnic groups. However, undiagnosed HIV prevalence rates within these communities have seen dramatic falls: for gay, bisexual, and other men who have sex with men, prevalence fell from 13.9 to 5.4 per 1,000, and for Black African heterosexuals prevalence fell from 3.3 to 1.7 per 1,000 population.

London saw more dramatic falls in the prevalence of undiagnosed HIV during the study period than other regions of England, down from 0.74 to 0.31 per 1,000, compared to a decrease from 0.20 to 0.11 per 1,000 outside London.

Although sexual health clinics provide free and confidential HIV testing to all clinic attendees, the researchers estimated that among heterosexuals in an ethnic group other than Black African, undiagnosed prevalence in clinic attendees in 2019 was more than 30 times greater than in those who had not attended in the past year. This implies that sexual health clinics are missing opportunities for testing attendees. This is in line with findings from Public Health England that among individuals outside those subgroups at greatest risk of HIV infection, the proportion declining a HIV test had increased to more than one in four (27%) in 2016.

̽��ֱ��researchers say their estimates have important implications for efforts to eliminate HIV transmission in England and the UK.

Dr Valerie Delpech, head of the HIV Team at Public Health England said: “This research is good news and shows that combination prevention, and in particular HIV testing and early treatment, is working in England. ̽��ֱ��increasing use of pre-exposure prophylaxis among persons at higher risk of HIV has further amplified our response to end HIV transmission. Nevertheless, further reducing the number of people who remain undiagnosed with HIV infection will become very challenging in the coming years. This is particularly the case for heterosexuals who may not consider themselves at risk of HIV.

“ ̽��ֱ��priority must be to ensure that all sexual health clinic attendees are offered and encouraged to accept a HIV test, regardless of ethnicity, rather than the 73% that currently do test. If we can increase the number of clinic attendees unaware of their HIV status who get tested and diagnosed, as well as improve partner notification, the prospect of eliminating HIV transmission becomes increasingly likely.”

̽��ֱ��research was funded by the Medical Research Council and Public Health England.

Reference
Presanis AM, et al. Trends in undiagnosed HIV prevalence in England and implications for eliminating HIV transmission by 2030: an evidence synthesis model. Lancet Public Health; 23 Sept 2021; DOI: 10.1016/S2468-2667(21)0042-0

England is on track to have diagnosed 95% of people living with HIV by 2025, putting it in a strong position to eliminate HIV transmission by 2030, say researchers at the MRC Biostatistics Unit, ̽��ֱ�� of Cambridge, and Public Health England (PHE).

Overall, we see a positive picture for the HIV epidemic in England, with a dramatic fall in the number of people living with undiagnosed HIV

Daniela De Angelis

Andy McCarthy

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Patients with SARS-CoV-2 Delta variant were more likely to be admitted to hospital compared to patients with Alpha variant

sc604 — Tue, 31 Aug 2021 09:29:45 +0000

In a new study published in ̽��ֱ��Lancet Infectious Diseases, researchers at Public Health England and the MRC Biostatistics Unit, ̽��ֱ�� of Cambridge, found that the estimated risk of hospital admission was two times higher for individuals diagnosed with the Delta variant of the SARS-CoV-2 virus, compared to those with the Alpha variant, after adjusting for differences in age, sex, ethnicity, deprivation, region of residence, date of positive test and vaccination status. When broadening the scope to look at the risk of either hospital admission or emergency care attendance, the risk was 1.45 times higher for Delta than Alpha.

This is the largest study to date to report on the risk of hospitalisation outcomes for cases with the Delta compared to the Alpha variant, using 43,338 Alpha and Delta cases confirmed through whole-genome sequencing who tested positive for COVID-19 between 29th March and 23rd May 2021. It is crucial to note that most of the Alpha and Delta cases in the study were unvaccinated or only partially vaccinated: 74% were unvaccinated, 24% were partially vaccinated, and only 2% were fully vaccinated. ̽��ֱ��results from this study therefore primarily tell us about the risk of hospital admission for those who are unvaccinated or partially vaccinated. Given the small number of hospitalised vaccinated cases, it has not been possible to estimate reliably if the hospitalisation risk differed between Delta and Alpha cases who had been fully vaccinated.

̽��ֱ��Delta variant is now the most common SARS-CoV-2 lineage in several higher-income and lower-income countries on all continents, currently accounting for more than 99% of new cases in England [2]. ̽��ֱ��evidence provided in this study therefore has implications for healthcare practice, planning and response in countries with ongoing or future Delta variant outbreaks, particularly in unvaccinated or partially vaccinated populations. As previous studies have shown Delta and Alpha spread more rapidly than previous variants [2–4], the combination of faster transmission and the current study’s finding of higher risk of severe disease requiring hospital admission in unvaccinated populations implies a more severe burden on healthcare of Delta outbreaks than of Alpha epidemics.

Previous studies have shown the available COVID-19 vaccines are highly effective against symptomatic infections with the Alpha variant [5], and are effective against symptomatic infections with the Delta variant, particularly after a full vaccination cycle with two doses [6,7]. For those who despite vaccination become infected, the vaccination protects against admission to hospital [8].

Dr Anne Presanis, Senior Statistician at the MRC Biostatistics Unit said:

"Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic. Getting fully vaccinated is crucial for reducing an individual’s risk of symptomatic infection with Delta in the first place, and, importantly, of reducing a Delta patient’s risk of severe illness and hospital admission.”

Dr Gavin Dabrera, Consultant Epidemiologist at Public Health England, said:

“This study confirms previous findings that people infected with Delta are significantly more likely to require hospitalisation than those with Alpha, although most cases included in the analysis were unvaccinated.

We already know that vaccination offers excellent protection against Delta and as this variant accounts for over 99% of COVID-19 cases in the UK, it is vital that those who have not received two doses of vaccine do so as soon as possible.

It is still important that if you have COVID-19 symptoms, stay home and get a PCR test as soon as possible.”

Reference:
Katherine A Twohig et al. 'Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with alpha (B.1.1.7) variants of concern: a cohort study.' ̽��ֱ��Lancet Infectious Diseases (2021). DOI: 10.1016/S1473-3099(21)00475-8

Largest study to date analysing more than 40,000 COVID-19 cases finds a two-fold increased risk of hospitalisation from delta versus alpha variant infections.

Getting fully vaccinated is crucial for reducing an individual’s risk of symptomatic infection with Delta in the first place, and, importantly, of reducing a Delta patient’s risk of severe illness and hospital admission

Anne Presanis

Steven Cornfield via Unsplash

Patient receives Covid-19 vaccine

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