HIV continues to be one of the most important communicable diseases in the UK. It is an infectionInvasion by organisms that may be harmful, for example bacteria or parasites. that is associated with serious illness and death, high cost of treatment and high numbers of potential years of life lost. Nevertheless, treatment advances over the last fifteen years following the introduction of highly active antiretroviral therapy has resulted in large reductions in AIDSAcquired immune deficiency syndrome, a deficiency of the immune system due to infection with HIV. incidences and deaths in the UK. However, many patients with HIV infection currently remain undiagnosed unfortunately, which means that they are not receiving treatment and support which could improve their health but also significantly reduces the chance of them transmitting the virusA microbe that is only able to multiply within living cells. to their partners. It is to this group that we need to direct our energies as, despite increased levels of testing leading to an increase in the prevalence of diagnosed infections, the prevalence of undiagnosed infections has not changed significantly over the last ten years.
Over 20,000 people in the UK are unaware of their infection
The number of people with HIV in the UK was estimated in the last report from the Health Protection Agency to be 86,500 with 26% of these are people unaware of their infection.
The key stages of HIV infection are as follows:
The symptoms vary and depend on the stage and type of an infection.
Primary HIV infection is classically described as an acuteHas a sudden onset. glandular feverA contagious disease caused by the Epstein-Barr virus, also known as infectious mononucleosis, characterised by a high temperature, sore throat and swollen lymph nodes. type illness occurring 2–6 weeks after infection. It normally lasts for one or two weeks, may be considerably longer in a few patients and for many patients may pass unnoticed.
The main symptoms are as follows:
The combination of symptoms of fever, maculopapular rash and lymphadenopathySwollen lymph nodes. are the most common.
Following acute HIV infection a viral set point which is governed by the unique immune response of the hosts of the virus is reached and patients enter the phase of chronicA disease of long duration generally involving slow changes. HIV infection.
During this time there is a steady reduction in CD4 cells and towards the end of this phase patients may begin to experience constitutionalNo medical condition. symptoms and develop illnesses referred to as indicator diseases. The rate of CD4 decline is very variableLiable to vary or change. with a small minority never progressing to AIDS, for example in long term non-progressors, while other patients may progress more rapidly. With progressiveContinuously increasing in extent or severity. loss of CD4 cells the patient may develop the relatively common symptoms of weight loss, neurocutaneous disease including severe dermatitis, recurrent oral ulceration, and herpes zoster as well as upper respiratory tractThe parts of the body that are involved in respiration. The respiratory tract includes the nasal passages, throat (pharynx), windpipe (trachea), bronchi and lungs. infections.
As the disease progresses and the CD4 declines further, the patients may develop chronic fever, unexplained fever, oral candidaA type of yeast or fungus. The term is sometimes also used to describe the infection resulting from it (candidiasis). The most common is Candida albicans, which causes thrush infections, most often of the vagina or mouth, oral leukoplakia and severe bacterial infections. Finally with advanced disease where the CD4 drops below 200 cells/mm3 patients are at risk of the AIDS-defining opportunistic infections which include PCP (a form of pneumoniaInflammation of one or both lungs.), cerebralRelating to the brain. toxoplasmas, CMV disease and the HIV related tumours such as lymphomaA type of cancer that affects the lymph nodes, part of the immune system. and Kaposi’s sarcomaCancer of the connective tissues..
The newly infected – increasing numbers of new diagnoses reflect the increased levels of HIV testing but many patients are not diagnosed for years after they were infected. However, the Health Protection Agency does try to estimate how many new infections are occurring in the UK and they estimate that there are 3000 new infections among men who have sex with men (MSM) each year and that a quarter of newly diagnosed MSM in 2010 probably acquired their infection in the few months prior to diagnosis. In heterosexual men and women there was estimated to be at least 300 to 400 new infections last year.
The groups at highest risk for HIV in the UK are MSM and people from black African communities; however these are not the only ones at risk. There are increasing numbers of people who have acquired their infection through heterosexual sexual contact in the UK. The other main routes of transmission are in sharing needles and syringes and mother to child transmission, however, in the UK these fortunately make up a very small proportion of cases with very few babies being infected in utero.
Although HIV infection is a problem across the UK there is a particularly large concentration of cases in London with more than 40% of infections reported in London residents.
Prognosis has improved immeasurably for patients with HIV infection in the UK and this is related to highly active antiretroviral therapy. We now have 24 licensed antiretroviral agents with drugs from a number of classes. These include the nucleoside reverse transcriptase inhibitors, the non-nucleoside reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors and CCR5 antagonistsDrugs that are used to counter the effects of naturally occurring chemicals in the body./entry inhibitors. All the drugs work by interfering with viral replicationThe process by which DNA makes copies of itself when a cell divides., some drugs are co-formulated and it is now usual for patients to be on a simple regimen of once, or at most twice, daily treatments.
Another very significant advance in the management of patients with HIV infection has been the availability of genotypic resistanceThe ability of a microbe, such as a type of bacteria, to resist the effects of antibiotics or other drugs. tests which have identified transmitted and acquired resistance and enabled clinicians to make the optimal drug choices for an individual when starting therapy and when patients develop virological failure. Many of the drugs do have both short- and long-term toxicities and given the number of drugs available regimens can be changed to one that is optimal for an individual patient.
The quality of HIV care in the UK is high and comparison with data from the US shows that treatment is superior in the UK. Based on London data, 80% of newly diagnosed patients were seen in an HIV clinic within one month of diagnosis. One year after starting therapy 90% had an undetectable viral load (less than 50 copies per ml) and 93% of those receiving care for more than a year had a CD4 count of over 200 cells per mm3. The uptake of HIV testing in antenatal clinics is very high with 95% having an HIV test, which has led to very small numbers of children being infected by mother-to-child transmission. In sexually transmitted infection clinics 77% of attendees in England agree to HIV testing.
In my clinic at the Royal Free Hospital there are approximately 3,000 patients receiving care. Around 38% acquired their infection heterosexually and approximately 30% are female. In 1993 there were 10.7 deaths per 100 patient-years and by 2008 this had fallen to 2 events per 100 patient-years. There were 28 AIDS events per 100 patient-years in 1992 which had fallen to 2.3 events per 100 patient-years by 2008. This has resulted in a dramatic reduction in hospitalisations with 38.1 hospitalisations per 100 patient-years in 1992 falling to 4.6 hospitalisations per 100 patient-years in 2008. The average CD4 cell count at the Royal Free of our patient clinical population was 290 cells per mm3 and by 2008 this had risen to 520 cells per mm3.
To put this in another way, anyone diagnosed with AIDS now, compared to twenty years ago, can expect both a more successful chance of life, as well as an improved quality of life.
We have become increasingly aware that for many patients infected with HIV an important factor is the management and treatment of the long-term consequences of the infection itself and the long-term toxicities of antiretroviral therapy. These include increased cardiovascular risk, osteoporosisA condition resulting in brittle bones due to loss of bony tissue., renalRelating to the kidney. disease, an increase in non-AIDS related cancers and neuro-cognitive disorders. It is essential that patients with HIV infection are looked after by physicians experienced in the management of this chronic infection.
I finally want to end on a plea for doctors in the UK to think about HIV infection in both general practice and secondary care. As discussed earlier, late diagnosis remains a considerable cause of serious illness and death and it is essential that HIV antibodyOne of a group of special proteins in the blood that are produced in response to a specific antigen and play a key role in immunity and allergy. testing is recommended by doctors when patients see them with clinical problems that could be related to HIV infection. The days when an HIV test needed individual counselling are gone. Any healthcare professional should be able to offer this to their patients when clinically indicated in high prevalence areas (greater than 2/1000 diagnosed with HIV infection). The routine offer and recommendation to accept an HIV test for all adult general practice patients and general medical admissions should be implemented.