This implementation guide supports the needs to effectively monitor the HIV key population & and measure their progress towards being virally suppressed. Key populations are defined groups who, due to specific higher-risk behaviors, are at increased risk of HIV, irrespective of the epidemic type or local context. Also, they often have legal and social issues related to their behaviors that increase their vulnerability to HIV (Geneva: World Health Organization, 2016). Key populations also play a role with regards to the dynamics associated with the effective responsiveness towards the epidemic.

Currently, only the following key populations are supported by this implementation guide.

1. Female sex workers (FSW)
2. General population
3. Male sex workers (MSW)
4. Men who have sex with men (MSM)
5. People who inject drugs (PWID)
6. People who use drugs (PWUD)
7. Transgender people

This implementation guide was derived using a functional requirement specification which was developed to support the following key HIV CBS sentinel events.

1. Antiretroviral therapy (ART) regimen switching: According to the World Health Organization (2010), a regimen switch may occur when:
   1. Where available, use viral load (VL) to confirm treatment failure.
   2. Where routinely available, use VL every 6 months to detect viral replication.
   3. A persistent VL of >5000 copies/ml confirms treatment failure.
   4. The VL is not available, use immunological criteria to confirm clinical failure.
2. ART initiation: According to the Initiation of Antiretroviral Therapy | NIH (2019), initiation into ART should happen as fast as possible after HIV diagnosis in order to increase the uptake of ART and linkage to care, decrease the time to viral suppression for individual patients, and improve the rate of virologic suppression among persons with HIV. This is essential to prevent HIV-associated morbidity and mortality.
3. CD4 first/subsequent sampling: The progressions of the HIV disease can be assessed by the immunologic status using the CD4 cell count (Ministry of Health – Moh, 2019). The progressive depletion of the CD4 cell count will eventually result in the weakening of the individuals immune ability to fight against HIV which ultimately leads to the death of patients during the terminal stage of the disease (Pattanapanyasat K, 2012).
4. Death: Patients who have died while infected with the disease.
5. Enrolled to care: Patients who are enrolled into a HIV program in order to receive ART therapy and other HIV related services.
6. HIV diagnosis: HIV can be diagnosed through blood or saliva. If an individual has been diagnosed with HIV, they should immediately be enrolled into care and start ART therapy, regardless of their stage of infection or complications.
7. Viral suppression first/subsequent sampling: Viral load tests are used to diagnose acute HIV infection, guide treatment choices, and monitor response to ART (Drain et al., 2019).

HIV CBS is the systematic reporting of newly diagnosed persons living with HIV (PLHIV) at the time of diagnosis and if applicable subsequent reporting of key clinical events (sentinel events) for that individual during the course of the disease.

The following key HIV CBS indicators have been identified for this implementation guide.

1. To calculate the number of individuals who have been newly diagnosed with HIV within the reporting period.
2. To calculate the number of newly diagnosed HIV positive individuals who have been enrolled into the HIV program within the reporting period.
3. To calculate the number of newly diagnosed HIV positive individuals who have been initiated on ART therapy within the reporting period.
4. To calculate the number of new ART individuals who are virally suppressed within the reporting period.
5. To calculate the number of HIV positive individuals who have died within the reporting period.

The following PEPFAR indicators can be implemented in order to support HIV case reporting.

• (HTS_TST) Calculate the number of individuals who received HIV Testing Services (HTS) and received their test results.
• (HTS_TST_POS) Calculate the number of individuals who received HTS and were diagnosed with HIV.
• (TX_NEW) Calculate the Number of adults and children newly enrolled on ART.
• (TX_CURR) Calculate the number of adults and children currently receiving ART.
• (TX_ML) Calculate the number of ART patients (currently on ART or newly initiating ART) with no clinical contact or ARV pick-up for greater than 28 days since their last expected clinical contact or ARV pick-up.
• (TX_RTT) Calculate the number of ART patients who experienced interruption in treatment (IIT) during any previous reporting period, who successfully restarted ARVs within the reporting period and remained on treatment until the end of the reporting period.
• (TX_PVLS) Calculate the number of ART patients with suppressed VL results (<1,000 copies/ml) documented in the medical or laboratory records/lab information system (LIS) within the past 12 months.

• Even though this implementation guide is able to support some of the key PEPFAR HIV reporting indicators, not all disaggregation groups per indicator will be supported.
• This implementation guide specification is currently limited to this minimum dataset.
• DISI's reference platform architecture enables HIV case reporting at national and sub-national levels.