Measles cases across the world

TidyTuesday 2025-06-24

geofacet

data.table

data-viz

Author

gnoblet

Published

June 24, 2025

Overview

This week’s TidyTuesday focused on measles cases across the world. I explored a very minimal viz around red rashes using a global point geofacet.

Dataset

# Libraries
box::use(
  gg = ggplot2,
  ggf = geofacet,
  ggt = ggtext,
  tidytuesdayR[tt_load],
  ggp = patchwork,
  data.table[...],
  sht = showtext,
  syf = sysfonts
)

# Get data
dat <- tt_load("2025-06-24")
dat_month <- dat$cases_month
setDT(dat_month)

Analysis

Data Preparation

# Aggregate by year
dat_month <- dat_month[,
  .(measles_clinical = sum(measles_clinical)),
  by = .(year, iso3)
]

Visualization

# Get grid
data("world_countries_grid1", package = "geofacet")

# Fonts
syf$font_add_google("Fascinate Inline", "Fascinate Inline")
sht$showtext_auto()
sht$showtext_opts(dpi = 600)
title_font <- "Fascinate Inline"

# Measles colors
colors <- c(
  '#F4A6A6', # light coral, reflecting the lighter areas of the rash
  '#E25822', # a strong red-orange, often used for rashes or spots
  '#B22222' # a deep firebrick, suitable for the darker spots or advanced rash stages
)

# Tag
tag <- "<span style='color:#B22222;font-size:22pt;'>Clinically-compatible measles cases</span><br><br>
                <span style='color:#E25822;font-size:14pt;'>A suspected case with fever, maculopapular rash, and at least one of cough, coryza, or conjunctivitis, without a clinical specimen or epidemiological link to a confirmed case.</span>"

# Plot
g <- gg$ggplot(dat_month) +
  gg$aes(
    x = year,
    y = measles_clinical,
    color = measles_clinical,
    size = measles_clinical
  ) +
  gg$geom_point() +
  gg$scale_size_continuous(range = c(0.3, 4.5)) +
  gg$scale_color_gradientn(colors = colors) +
  ggf$facet_geo(~iso3, grid = 'world_countries_grid1') +
  gg$theme_void() +
  gg$labs(tag = tag) +
  gg$theme(
    plot.background = gg$element_rect(fill = 'white'),
    strip.background = gg$element_blank(),
    strip.text.x = gg$element_blank(),
    legend.position = 'none',
    plot.tag.position = c(0.05, 0.15),
    plot.tag = ggt$element_textbox_simple(
      family = title_font,
      width = gg$unit(4.5, "inch"),
      lineheight = 1.2,
      hjust = 0
    )
  )

# Create the main visualization
gg$ggsave('week_25.png', g, height = 10, width = 16, dpi = 600)

Technical Notes