HIV News from NAM aidsmap

Shigella: the nasty stomach bug you need to know about

Each month in Boyz the team from NAM aidsmap will be reporting the latest news on HIV and sexual health. You can also keep up to date and read more on their website at

Public Health England have issued a warning about a highly drug-resistant strain of a serious bacterial gut infection that can be contracted through sex. Between March and November last year, 17 cases of Shigella dysentery with resistance to several first-line antibiotics were detected in the UK. Most of those affected are gay men.

Standard treatment with first-line antibiotics may not be effective, though other antibiotics will still work.

Shigella is transmitted by contact with very small amounts of human faeces (shit) and can be passed on during sex. Rimming, fingering, fisting, anal sex, handling sex toys after use in the anus, and occasionally oral sex can all carry a risk. The bacteria can easily be passed from fingers to the mouth during sex sessions.

Using condoms for anal sex and latex gloves for fisting, as well as washing your hands frequently, can help prevent transmission of Shigella.

Symptoms typically occur within three days of exposure and include:

Frequent diarrhoea lasting more than 48 hours

Stomach cramps



General weakness and tiredness.

Shigella can be especially serious in people living with HIV who have a low CD4 count (which indicates a weakened immune system).

If you have these symptoms, go to see your GP or a sexual health clinic, mentioning Shigella.


Find out more about Shigella at

PrEP and sexually transmitted infections

Pre-exposure prophylaxis (PrEP) is a pill you can take which stops you getting HIV. But it doesn’t stop you getting chlamydia, gonorrhoea or other sexually transmitted infections (STIs). Some people worry that if more gay men protect themselves with PrEP rather than condoms, rates of STIs will go up.

To see whether this is the case, Dr Ricardo Werner of the Berlin Institute of Health pooled the data from almost 12,000 gay men who’ve taken part in 20 different PrEP studies. His review shows that there are no simple answers.

He did find that STIs are very common in PrEP users – overall, for every 100 men taking PrEP for a year, there may be as many as 84 STIs. But the rates vary between different cities, groups of PrEP users, and individuals.

In fact, some PrEP users have STIs several times in a year and some have none. In one Australian study, 13% of the men had 53% of all the STI diagnoses.

And a simple comparison between PrEP users and non-PrEP users isn’t helpful. That’s because the two groups tend to have different sexual behaviour anyway. Men who don’t always use condoms are most likely to benefit from PrEP and are especially likely to seek it out. The studies show that they often had higher rates of STIs before they took PrEP as well.

Something else that complicates the picture is that PrEP users should attend sexual health clinics for HIV and STI screening every three months. This means that STIs get diagnosed much more quickly in PrEP users than in other people.

This makes the figures on STIs in PrEP users look bad but it’s much better for everyone’s health. In fact, one of the positive spin-offs of PrEP may be that it helps people connect with sexual health clinics and get STIs treated without delay.


Find out more about PrEP at

HIV and the ageing process

There’s scientific debate about whether HIV speeds up the ageing process. There is still a lot that we don’t know about this, but a study from University College London and the University of Amsterdam gives a partial answer.

The researchers wanted to compare ‘chronological age’ (the number of years a person has lived) with ‘biological age’. There is no agreed definition of biological age, but the researchers tried to estimate this by measuring a set of ten molecules found in blood or body tissues. Each one is a sign of age-related changes in the body.

They looked at three groups of people:

People living with HIV (mostly gay men), over the age of 45. Their estimated biological age was 13 years older than their chronological age.

People of the same age who had very similar lifestyles to those living with HIV but were HIV negative. Again, they were mostly gay men and were similar in terms of exercise, diet, smoking, drug use and so on. Their biological age was six years older than their chronological age.

Dutch blood donors – an unusually healthy group of people. Their estimated biological age was seven years younger than their chronological age.

It seems that one reason for the greater biological ageing of people with HIV in this study is viral infections, substance use and other lifestyle factors. These are things the first group have in common with the second group, who were also biologically ‘older’ than their chronological age.

But there must be additional factors that also have an impact on those living with HIV. Despite the fact that they were all currently receiving effective treatment and good medical care, people with HIV in this study had a more advanced biological age than their HIV-negative peers.

The researchers say that some of this is probably due to damage to their immune systems, before they started to take HIV treatment.


Find out more about HIV and the ageing process at

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