HIV diagnoses had fallen by half, and then 129 appeared in two towns

From 2000 to 2014, annual HIV diagnoses in Massachusetts fell 47%.

In August 2016, one community health centre in Lawrence reported **five
new cases among people who inject drugs.** The usual rate across all
providers in Lawrence during 2014–2015 had been fewer than one a month.

By 30 June 2018 the investigation had identified 129 people.

Who they were

Cases were defined three ways — by injection drug use with a connection to
Lawrence or Lowell, by being an injecting or sexual partner of someone in the
outbreak, or **molecularly, by an HIV sequence within 1.5% genetic distance of
another person's in the investigation.** The third catches people who could not
be connected any other way.

What drove it

**Stakeholders reported that fentanyl had replaced heroin locally, was cheaper
in Lawrence than in other cities in the region, and had increased injection
frequency.**

That chain is the whole mechanism. Fentanyl is short-acting, so a person
injects more often — and each injection is an opportunity to share equipment.
The transmission risk rose without anyone's behaviour becoming more reckless.

Interviews with 34 people who inject drugs also reported **sharing syringes
and other equipment, homelessness, incarceration, and exchanging sex for
drugs** in the previous year.

Two obstacles that had nothing to do with the virus

Homelessness and frequent incarceration undermined HIV treatment success —
interrupted treatment, missed appointments, and multiple care providers.
Treatment that makes someone non-infectious requires taking it daily, which
requires a life stable enough to hold a routine.

And syringe services access:

A service that closes at five on a Friday is closed for the two days and the
evenings when most injecting happens.

What the genetics showed

Multiple molecular clusters and unlinked infections — indicating **multiple
introductions of HIV among people who inject drugs, as well as recent and rapid
transmission, alongside some longstanding infections.**

Not one person seeding an outbreak. Several separate introductions into a
population whose injection frequency had risen and whose access to clean
equipment had not.

The response

**Lawrence and Lowell approved state-funded syringe services programmes in 2016
and 2018.** Massachusetts **deployed additional field staff to link people to
care and provide partner services**, and is **expanding services addressing the
homelessness and incarceration behind the instability** — plus continued
testing, field investigation and molecular cluster detection statewide.

**Opioid overdose deaths had been rising rapidly in Lawrence and Lowell since
2013**, with postmortem fentanyl detection rising statewide. The HIV outbreak
and the overdose crisis are the same event seen from two directions.

Source: Centers for Disease Control and Prevention, MMWR.