Prevalence of night blindness and number of individuals affected among preschool-age children and pregnant women in populations of countries at risk of vitamin A deficiency 1995-2005, globally and by WHO region
WHO regional estimates indicate that the highest proportion of preschool-age children affected by night blindness, 2.0%, is in Africa, a value that is four times of that estimated in South-East Asia (0.5%). This also means that Africa has the greatest number of preschool-age children affected with night blindness (2.55 million), and corresponds to almost half of the children affected globally. A comparable and high proportion of pregnant women affected by night blindness are in Africa (9.8%) and South-East Asia (9.9%), each of which is estimated to have over 3 million pregnant women affected, or one third of the pregnant women affected globally.
| WHO region | Preschool-age childrena | Pregnant women | ||
| Prevalenceb (%) | Number affected (millions) |
Prevalence (%) | Number affected (millions) |
|
| Africa | 2.0 (0.8-3.2)c |
2.55 (0.99-4.11) |
9.8 (8.4-11.1) |
3.02 (2.59-3.44) |
| Americas | 0.6 (0.0-1.3) |
0.36 (0.00-0.75) |
4.4 (2.7-6.2) |
0.5 (0.30-0.70) |
| South-East Asia | 0.5 (0.0-2.0) |
1.01 (0.00-3.75) |
9.9 (9.5-10.3) |
3.84 (3.69-4.00) |
| Europe | 0.8 (0.1-1.5) |
0.24 (0.04-0.44) |
3.5 (1.8-5.3) |
0.22 (0.11-0.33) |
| Eastern Mediterranean | 1.2 (0.6-1.7) |
0.77 (0.41-1.12) |
7.2 (5.2-9.2) |
1.09 (0.78-1.39) |
| Western Pacific | 0.2 (0.0-0.4) |
0.26 (0.02-0.50) |
4.8 (0.9-8.6) |
1.09 (0.20-1.97) |
| Global | 0.9 (0.3-1.5) |
5.17 (1.97-8.38) |
7.8 (7.0-8.7) |
9.75 (8.70-10.8) |
a Population subgroups: Preschool-age children (<5 years); Pregnant women (no age range defined).
b Numerator and denominator excludes countries with a 2005 GDP ≥US$ 15 000.
c 95% Confidence Intervals.
Source
WHO. Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO Global Database on Vitamin A Deficiency. Geneva, World Health Organization, 2009.