Enter the Total Parasite Incidences in a year and the Total Population into the calculator to determine the Annual Parasite Index. This calculator can also evaluate any of the variables given the others are known.

## Annual Parasite Index Formula

The following formula is used to calculate the Annual Parasite Index (API).

API = (TPI / TP) * 1000

Variables:

- API is the Annual Parasite Index (per 1000 population)
- TPI is the Total Parasite Incidences in a year
- TP is the Total Population

To calculate the Annual Parasite Index, divide the Total Parasite Incidences in a year by the Total Population. Multiply the result by 1000 to get the API.

## What is an Annual Parasite Index?

The Annual Parasite Index (API) is a measure used in epidemiology to assess the risk and prevalence of malaria in a specific geographical area. It is calculated by dividing the total number of confirmed malaria cases in a year by the total population at risk, and then multiplying the result by 1,000. This index helps health authorities to monitor and evaluate the effectiveness of malaria control programs and to allocate resources efficiently.

## How to Calculate Annual Parasite Index?

The following steps outline how to calculate the Annual Parasite Index (API).

- First, determine the Total Parasite Incidences (TPI) in a year.
- Next, determine the Total Population (TP).
- Next, use the formula API = (TPI / TP) * 1000.
- Finally, calculate the Annual Parasite Index (API).
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem:**

Use the following variables as an example problem to test your knowledge.

Total Parasite Incidences (TPI) = 120

Total Population (TP) = 5000