An “HIV cluster” is a group of people living with HIV whose HIV strain appear to be related; they can represent groups of rapid transmission. The Department of State Health Services (DSHS) uses clusters to monitor the HIV epidemic, which improves access to and engagement in, HIV-related services. “HIV cluster response” is how health departments respond to these clusters. New laboratory methods and epidemiological techniques (epidemiology is the study and analysis of the distribution, patterns, and determinants of health and disease conditions in defined populations) allow us to see where HIV may be spreading most rapidly, thereby allowing CDC and DSHS to quickly develop and implement strategies to stop ongoing transmission. Real-time response systems are key to ending the HIV epidemic.

In rapidly growing clusters of HIV, it has been demonstrated that HIV transmission is occurring in these networks at 10-11 times the rate we see in the general population. Focusing prevention efforts in these areas and or groups allow public health staff to make the most impact within our limited budget and resource constraints. Similar to the fact that persons in the acute stage of HIV and who are unaware of their HIV status are more likely to pass on HIV, clusters of HIV may indicate “hot-spots” where we can focus resources and efforts to halt ongoing transmission and new HIV infections.

Molecular analysis using drug resistance HIV genotype data reported to HIV surveillance. This analysis looks for very similar viral RNA sequences that can indicate that two people are closely related in a transmission network. This can mean that person to person transmission is happening in this network at a higher-than-expected rate. We cannot determine directionality of transmission, and patient human DNA is never used for this analysis.

Time/Space cluster detection happens when a higher-than-expected number of new HIV cases are diagnosed in a given geographic location. This analysis looks at monthly diagnoses by county over the past several years. It alerts epidemiologists at central office when a higher than “normal” number of cases are diagnosed.

Sometimes medical providers or DIS notice changes in diagnosis or risk factor collection that seem strange and higher than expected. They contact DSHS to notify the state of a possible cluster.

CDC recommends that everyone between the ages of 13 to 64 get tested for HIV at least one and those in higher risk groups get tested yearly. Knowing your HIV status gives you powerful information to keep you and your partner healthy.

You can ask your health care provider for an HIV test. Many medical clinics, substance abuse programs, community health centers, and hospitals offer them too. You can also find a testing site near you by

• visiting gettested.cdc.gov, or
• calling 800-CDC-INFO (232-4636).

HIV drug resistance testing is a lab test used to determine which HIV treatment will be most effective for a person living with HIV. It can help medical providers to select a drug regimen that will likely be effective in treating your HIV infection. This test is used to determine if your HIV strain is resistance to one or more of the drugs used to treat HIV.

It is recommended that HIV drug resistance testing is conducted at entry to HIV care. You can seek HIV drug resistance testing at your HIV medical care provider or your primary care provider. Testing requires a blood sample.

By law, certain health information is required to be sent to the health department by hospitals, medical providers, and laboratories. The health department is also required to protect and prevent any personal information from being released. De-identified health information is regularly sent to the Centers for Disease control and Prevention (CDC). All health information collected by the health department is confidential.

It is important that you start medical care and begin HIV treatment as soon as you are diagnosed with HIV. Antiretroviral therapy or ART (taking medicine to treat HIV infection) is recommended for all people with HIV, regardless of how long they’ve had the virus or how healthy they are. HIV medicine works by lowering the amount of virus in your body to very low levels. HIV medicine can make the viral load so low that a test can’t detect it (called an undetectable viral load). HIV medicine slows the progression of HIV and helps protect your immune system. If you take HIV medicine as prescribed and get and keep an undetectable viral load, you can stay healthy for many years. Having an undetectable viral load also helps prevent transmitting the virus to others.

• In rapidly growing clusters of HIV, it has been demonstrated that HIV transmission is occurring in these networks at 10-11 times the rate we see in the general population.
• Currently the health department is not notifying PLWH that they are part of a cluster as cluster notification has the possibility of increasing stigma and causing public concern.