About the data
2.18
Definitions
People’s health is influenced by the environment
the use of oral rehydration therapy have changed over
• Access to an improved water source refers to
in which they live. Lack of clean water and basic
time based on scientific progress, so it is difficult
people with access to at least 20 liters of water
sanitation is the main reason diseases transmitted
to accurately compare use rates across countries.
a person a day from an improved source, such as
by feces are so common in developing countries.
Until the current recommended method for home
piped water into a dwelling, public tap, tubewell,
Access to drinking water from an improved source
management of diarrhea is adopted and applied in
protected dug well, and rainwater collection, within
and access to improved sanitation do not ensure
all countries, the data should be used with caution.
1 kilometer of the dwelling. • Access to improved
safety or adequacy, as these characteristics are
Also, the prevalence of diarrhea may vary by season.
sanitation facilities refers to people with at least
not tested at the time of the surveys. But improved
Since country surveys are administered at different
adequate access to excreta disposal facilities that
drinking water technologies and improved sanitation
times, data comparability is further affected.
can effectively prevent human, animal, and insect
facilities are more likely than those characterized
Malaria is endemic to the poorest countries in the
contact with excreta. Improved facilities range from
as unimproved to provide safe drinking water and to
world, mainly in tropical and subtropical regions of
protected pit latrines to flush toilets. • Child immu-
prevent contact with human excreta. The data are
Africa, Asia, and the Americas. Insecticide-treated
nization rate refers to children ages 12–23 months
derived by the Joint Monitoring Programme (JMP)
nets, properly used and maintained, are one of the
who, before 12 months or at any time before the
of the World Health Organization (WHO) and United
most important malaria-preventive strategies to limit
survey, had received one dose of measles vaccine
Nations Children’s Fund (UNICEF) based on national
human-mosquito contact.
and three doses of diphtheria, pertussis (whooping
censuses and nationally representative household
Prompt and effective treatment of malaria is a criti-
cough), and tetanus (DTP3) vaccine. • Children with
surveys. The coverage rates for water and sanita-
cal element of malaria control. It is vital that suffer-
acute respiratory infection (ARI) taken to health
tion are based on information from service users
ers, especially children under age 5, start treatment
provider are children under age 5 with ARI in the
on the facilities their households actually use rather
within 24 hours of the onset of symptoms, to pre-
two weeks before the survey who were taken to an
than on information from service providers, which
vent progression—often rapid—to severe malaria
appropriate health provider. • Children with diarrhea
may include nonfunctioning systems. While the esti-
and death.
who received oral rehydration and continuous feed-
mates are based on use, the JMP reports use as
Data on the success rate of tuberculosis treatment
ing are children under age 5 with diarrhea in the two
access, because access is the term used in the Mil-
are provided for countries that have submitted data
weeks before the survey who received either oral
lennium Development Goal target for drinking water
to the WHO. The treatment success rate for tuber-
rehydration therapy or increased fluids, with con-
and sanitation.
culosis provides a useful indicator of the quality of
tinuous feeding. • Children sleeping under treated
Governments in developing countries usually
health services. A low rate suggests that infectious
nets are children under age 5 who slept under an
finance immunization against measles and diphthe-
patients may not be receiving adequate treatment.
insecticide-treated net to prevent malaria the night
ria, pertussis (whooping cough), and tetanus (DTP)
An important complement to the tuberculosis treat-
before the survey. • Children with fever receiving
as part of the basic public health package. In many
ment success rate is the case detection rate, which
antimalarial drugs are children under age 5 who were
developing countries lack of precise information on
indicates whether there is adequate coverage by the
ill with fever in the two weeks before the survey and
the size of the cohort of one-year-old children makes
recommended case detection and treatment strat-
received any appropriate (locally defined) antimalarial
immunization coverage difficult to estimate from
egy. Uncertainty bounds for the case detection rate,
drugs. • Tuberculosis treatment success rate is new
program statistics. The data shown here are based
not shown in the table, are available at http://data.
registered infectious tuberculosis cases that were
on an assessment of national immunization cover-
worldbank.org or the original source.
cured or that completed a full course of treatment as
age rates by the WHO and UNICEF. The assessment
Editions before 2010 included the tuberculosis
a percentage of smear-positive cases registered for
considered both administrative data from service
detection rates by DOTS, the internationally rec-
treatment outcome evaluation. • Tuberculosis case
providers and household survey data on children’s
ommended strategy for tuberculosis control. This
detection rate is newly identified tuberculosis cases
immunization histories. Based on the data available,
year’s edition, like last year’s, shows the tuberculo-
(including relapses) as a percentage of estimated
consideration of potential biases, and contributions
sis detection rate for all detection methods, so data
incident cases (case detection, all forms).
of local experts, the most likely true level of immuni-
on the case detection rate cannot be compared with
zation coverage was determined for each year. Acute
data in previous editions.
respiratory infection continues to be a leading cause
For indicators that are from household surveys, the
of death among young children, killing about 2 million
year in the table refers to the survey year. For more
children under age 5 in developing countries each
information, consult the original sources.
year. Data are drawn mostly from household health surveys in which mothers report on number of episodes and treatment for acute respiratory infection. Since 1990 diarrhea-related deaths among children have declined tremendously. Most diarrhea-related deaths are due to dehydration, and many of these deaths can be prevented with the use of oral rehydration salts at home. However, recommendations for
Data sources Data on access to water and sanitation are from the WHO and UNICEF’s Progress on Sanitation and Drinking Water (2010). Data on immunization are from WHO and UNICEF estimates (www.who.int/ immunization_monitoring). Data on children with ARI, with diarrhea, sleeping under treated nets, and receiving antimalarial drugs are from UNICEF’s State of the World’s Children 2010, Childinfo, and Demographic and Health Surveys by Macro International. Data on tuberculosis are from the WHO’s Global Tuberculosis Control: A Short Update to the 2010 Report.
2011 World Development Indicators
105
people
Disease prevention coverage and quality