diff --git a/DESCRIPTION b/DESCRIPTION
index 93235242..c9dff954 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: AMR
-Version: 2.0.0.9015
-Date: 2023-05-12
+Version: 2.0.0.9018
+Date: 2023-05-17
 Title: Antimicrobial Resistance Data Analysis
 Description: Functions to simplify and standardise antimicrobial resistance (AMR)
   data analysis and to work with microbial and antimicrobial properties by
diff --git a/NEWS.md b/NEWS.md
index d8bfedf6..0dd1195f 100755
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,16 +1,17 @@
-# AMR 2.0.0.9015
+# AMR 2.0.0.9018
 
 ## Changed
 * Added oxygen tolerance to over 25,000 bacteria in the `microorganisms` data set
   * Added `mo_oxygen_tolerance()` to retrieve the values
   * Added `mo_is_anaerobic()` to determine which species are obligate anaerobic bacteria
 * Added LPSN and GBIF identifiers, and oxygen tolerance to `mo_info()`
-* formatting fix for `sir_interpretation_history()`
-* Fixed some WHONET codes for microorganisms and consequently a couple of entries in `clinical_breakpoints`
+* Added SAS Transport files (file extension `.xpt`) to [our download page](https://msberends.github.io/AMR/articles/datasets.html) to use in SAS software
 * Added microbial codes for Gram-negative/positive anaerobic bacteria
 * `mo_rank()` now returns `NA` for 'unknown' microorganisms (`B_ANAER`, `B_ANAER-NEG`, `B_ANAER-POS`, `B_GRAMN`, `B_GRAMP`, `F_FUNGUS`, `F_YEAST`, and `UNKNOWN`)
+* Fixed formatting for `sir_interpretation_history()`
+* Fixed some WHONET codes for microorganisms and consequently a couple of entries in `clinical_breakpoints`
 * Fixed a bug for `as.mo()` that led to coercion of `NA` values when using custom microorganism codes
-* Added SAS Transport files (file extension `.xpt`) to [our download page](https://msberends.github.io/AMR/articles/datasets.html) to use in SAS software
+* Fixed usage of `icu_exclude` in `first_isolates()`
 
 
 # AMR 2.0.0
diff --git a/R/first_isolate.R b/R/first_isolate.R
index b04a613a..1283df01 100755
--- a/R/first_isolate.R
+++ b/R/first_isolate.R
@@ -191,13 +191,13 @@ first_isolate <- function(x = NULL,
   }
   meet_criteria(col_specimen, allow_class = "character", has_length = 1, allow_NULL = TRUE, is_in = colnames(x))
   if (is.logical(col_icu)) {
-    meet_criteria(col_icu, allow_class = "logical", has_length = c(1, nrow(x)), allow_NULL = TRUE)
-    if (length(col_icu) == 1) {
-      col_icu <- rep(col_icu, nrow(x))
-    }
-  } else {
+    meet_criteria(col_icu, allow_class = "logical", has_length = c(1, nrow(x)), allow_NA = TRUE)
+    x$newvar_is_icu <- col_icu
+  } else if (!is.null(col_icu)) {
     meet_criteria(col_icu, allow_class = c("character", "logical"), has_length = 1, allow_NULL = TRUE, is_in = colnames(x))
-    col_icu <- x[, col_icu, drop = TRUE]
+    x$newvar_is_icu <- x[, col_icu, drop = TRUE]
+  } else {
+    x$newvar_is_icu <- NA_real_
   }
   # method
   method <- coerce_method(method)
@@ -251,14 +251,13 @@ first_isolate <- function(x = NULL,
         "Determining first isolates ",
         ifelse(method %in% c("episode-based", "phenotype-based"),
           ifelse(is.infinite(episode_days),
-            "without a specified episode length",
-            paste("using an episode length of", episode_days, "days")
+            paste(font_bold("without"), " a specified episode length"),
+            paste("using an episode length of", font_bold(paste(episode_days, "days")))
           ),
           ""
         )
       ),
-      as_note = FALSE,
-      add_fn = font_black
+      add_fn = font_red
     )
   }
 
@@ -358,8 +357,7 @@ first_isolate <- function(x = NULL,
   # remove testcodes
   if (!is.null(testcodes_exclude) && isTRUE(info) && message_not_thrown_before("first_isolate", "excludingtestcodes")) {
     message_("Excluding test codes: ", vector_and(testcodes_exclude, quotes = TRUE),
-      add_fn = font_black,
-      as_note = FALSE
+      add_fn = font_red
     )
   }
 
@@ -372,8 +370,7 @@ first_isolate <- function(x = NULL,
     check_columns_existance(col_specimen, x)
     if (isTRUE(info) && message_not_thrown_before("first_isolate", "excludingspecimen")) {
       message_("Excluding other than specimen group '", specimen_group, "'",
-        add_fn = font_black,
-        as_note = FALSE
+        add_fn = font_red
       )
     }
   }
@@ -455,15 +452,13 @@ first_isolate <- function(x = NULL,
         message_("Basing inclusion on key antimicrobials, ",
           ifelse(ignore_I == FALSE, "not ", ""),
           "ignoring I",
-          add_fn = font_black,
-          as_note = FALSE
+          add_fn = font_red
         )
       }
       if (type == "points") {
         message_("Basing inclusion on all antimicrobial results, using a points threshold of ",
           points_threshold,
-          add_fn = font_black,
-          as_note = FALSE
+          add_fn = font_red
         )
       }
     }
@@ -505,34 +500,28 @@ first_isolate <- function(x = NULL,
       x$newvar_genus_species != "" &
       (x$other_pat_or_mo | x$more_than_episode_ago)
   }
-
+  
+  decimal.mark <- getOption("OutDec")
+  big.mark <- ifelse(decimal.mark != ",", ",", " ")
+  
   # first one as TRUE
   x[row.start, "newvar_first_isolate"] <- TRUE
   # no tests that should be included, or ICU
   if (!is.null(col_testcode)) {
     x[which(x[, col_testcode] %in% tolower(testcodes_exclude)), "newvar_first_isolate"] <- FALSE
   }
-
-  if (!is.null(col_icu)) {
+  if (any(!is.na(x$newvar_is_icu)) && any(x$newvar_is_icu == TRUE, na.rm = TRUE)) {
     if (icu_exclude == TRUE) {
       if (isTRUE(info)) {
-        message_("Excluding ", format(sum(col_icu, na.rm = TRUE), big.mark = " "), " isolates from ICU.",
-          add_fn = font_black,
-          as_note = FALSE
-        )
+        message_("Excluding ", format(sum(x$newvar_is_icu, na.rm = TRUE), decimal.mark = decimal.mark, big.mark = big.mark), " isolates from ICU.",
+                 add_fn = font_red)
       }
-      x[which(col_icu), "newvar_first_isolate"] <- FALSE
+      x[which(x$newvar_is_icu), "newvar_first_isolate"] <- FALSE
     } else if (isTRUE(info)) {
-      message_("Including isolates from ICU.",
-        add_fn = font_black,
-        as_note = FALSE
-      )
+      message_("Including isolates from ICU.")
     }
   }
 
-  decimal.mark <- getOption("OutDec")
-  big.mark <- ifelse(decimal.mark != ",", ",", " ")
-
   if (isTRUE(info)) {
     # print group name if used in dplyr::group_by()
     cur_group <- import_fn("cur_group", "dplyr", error_on_fail = FALSE)
@@ -560,11 +549,12 @@ first_isolate <- function(x = NULL,
   # handle empty microorganisms
   if (any(x$newvar_mo == "UNKNOWN", na.rm = TRUE) && isTRUE(info)) {
     message_(
-      ifelse(include_unknown == TRUE, "Included ", "Excluded "),
+      ifelse(include_unknown == TRUE, "Including ", "Excluding "),
       format(sum(x$newvar_mo == "UNKNOWN", na.rm = TRUE),
         decimal.mark = decimal.mark, big.mark = big.mark
       ),
-      " isolates with a microbial ID 'UNKNOWN' (in column '", font_bold(col_mo), "')"
+      " isolates with a microbial ID 'UNKNOWN' (in column '", font_bold(col_mo), "')",
+      add_fn = font_red
     )
   }
   x[which(x$newvar_mo == "UNKNOWN"), "newvar_first_isolate"] <- include_unknown
@@ -572,10 +562,11 @@ first_isolate <- function(x = NULL,
   # exclude all NAs
   if (anyNA(x$newvar_mo) && isTRUE(info)) {
     message_(
-      "Excluded ", format(sum(is.na(x$newvar_mo), na.rm = TRUE),
+      "Excluding ", format(sum(is.na(x$newvar_mo), na.rm = TRUE),
         decimal.mark = decimal.mark, big.mark = big.mark
       ),
-      " isolates with a microbial ID 'NA' (in column '", font_bold(col_mo), "')"
+      " isolates with a microbial ID `NA` (in column '", font_bold(col_mo), "')",
+      add_fn = font_red
     )
   }
   x[which(is.na(x$newvar_mo)), "newvar_first_isolate"] <- FALSE