HIV CLUSTER AND OUTBREAK DETECTION AND RESPONSE

HIV cluster detection and response (CDR) is an important, real-time public health strategy used to find areas where HIV is spreading quickly. It is a main part of the federal program called Ending the HIV Epidemic in the U.S. 

By finding these clusters and outbreaks, CDR helps public health agencies and communities to improve the services for preventing and treating HIV. These important services include:

  • Connecting people to HIV testing
  • Giving people access to medical care
  • Offering pre-exposure prophylaxis (PrEP)

The final goal of CDR is to stop HIV from spreading.

What We Do and Why

  • We use data to find communities affected by rapid HIV spread.
  • We help local public health agencies reach communities and people who urgently need HIV prevention and treatment services.
  • We partner with local organizations to provide needed services in order to stop the spread of HIV and meet people’s needs.

How do we find clusters and outbreaks of HIV? 

  • Medical providers, public health staff, or others in the community may notice an increase in HIV diagnoses among a specific group of people.
  • CDC and health departments analyze HIV surveillance data and may identify areas where HIV diagnoses are increasing.

Data Tools

 

Time-space

Time-space analysis is the process of looking at where something happened (location) and when it happened (time) together to understand a pattern. Time-space cluster analysis uses a computer program to track patterns in HIV diagnoses within certain timeframes and geographical areas. For example, the computer program may track a certain number of new diagnoses during the month of November (time) within a certain county (space). 

Molecular analysis

We use information about the structure of the HIV virus (called molecular information) in public health to follow, study, and stop the spread of infection. We get this information by looking closely at the virus's genetic code. This information usually comes from regular drug resistance tests. By studying these codes, health officials can find HIV clusters—groups of infections that have very similar genetic information. Finding these clusters helps them know where to focus resources, improve prevention efforts (like PrEP), and understand how the virus is spreading in communities.

The HIV genetic data is only about the makeup of the virus itself; it has nothing to do with an individual person’s own genetic makeup. This method of looking at molecular sequence data has been used for many years to track other diseases, such as foodborne infections and tuberculosis. This data helps identify related infections that might otherwise be missed and helps public health efforts focus on the areas that need them most.

How do we respond to clusters and outbreaks of HIV? 

 

Our Usual Process

When a person is newly diagnosed with HIV in West Virginia, we contact that person individually to help link them to services they need, like medical care or housing. We also make sure any of their recent partners, including sex and needle sharing partners, get tested for HIV.

Responding to Clusters of HIV

When HIV is spreading fast, it shows us that our normal system isn't helping the people who need it. When this happens, we may decide that we need to respond with additional activities. If we do, public health staff work with groups in the community, doctors, and others to carry out this plan.

This response plan might include:

  • Doing outreach in the area to offer testing and education.
  • Making medical help like HIV treatment and PrEP easier to get.
  • Giving out free prevention services such as condoms, PrEP, and safer supplies for injecting drugs.
  • Other actions, depending on what the people in the group need the most.

That is why finding these groups, or clusters, is so important. If we find the cluster and the people involved fast, we can give them help, stop the spread of HIV, and keep new cases from happening.

The response ends when the people linked to the cluster have gotten HIV care and other help they need and the data doesn’t show any more rapid transmission. After that, we meet to discuss how it went and what we can do better next time. 

Outbreak Response Plan

Response plans are a good way to be ready if an outbreak happens. They help us know what to do and who to call. The response will change depending on a few things: who is part of the cluster and what they need; where the cluster is and what help is available; and which local groups need to be involved. A single plan for the whole state can’t cover all those different needs.

Our office has created a statewide plan for HIV clusters and outbreaks. This plan explains who in our office finds and keeps track of clusters, and how we would plan a response. We update it each year. We are also working with local health departments and community groups to help them write their part of the plan, which will include specific community needs, resources, and partners.

Resources