You need to remember the state of each input, and only output to the UART if it changes. 

Something like this, just for one input so you get the idea :

    // NB - put these lines outside your loop
    uint8_t uLastRA6State = 0;                // last known state of RA6
    uint8_t uLastRA7State = 0;                // last known state of RA7
    // ... etc. 
    // use one variable for each input

    while (1)
    {
        // ...

        // NB - put this code inside your loop
        if (PORTAbits.RA6 != uLastRA6State)
        {
            // save current state
            uLastRA6State = uLastRA6State ? 0 : 1;

            // output change
            if (uLastRA6State)
                putsUART2("Input: 1 ON\n");
            else
                putsUART2("Input: 1 OFF\n");
        }

        // ... do the same for other inputs, e.g.
        if (PORTAbits.RA7 != uLastRA7State)
        {
            // ... similar to above, for RA7
        }
    }