Following is a response from DHS Senior Research Associate, Cameron Taylor:
You can use the following code to replicate % of households with IRS in last 12 months. I am not sure which survey you are trying to replicate but this is the standard code that will work with most surveys. If the code below is still not matching be sure to check for any country specific spraying variables hv253d-hv253h that might be applicable to the survey of interest.
Use HR file
g wt= hv005/1000000
replace irs=1 if hv253==1 & (hv253a==1|hv253b==1|hv253c==1)
tab irs [iweight=wt]