Since I couldn’t find enough data, I’ve decided to change my problem
definition.
New Problem
Definition: The rising incidence and prevalence of dengue in Latin America
during the last two decades.
Dengue incidence and prevalence are rising in endemic
areas of the tropical and subtropical regions. On the basis of mathematical
model estimates, approximately 50 million infections occur each year. In the
past, the burden of the disease has fallen on countries in South-East Asia and
the Western Pacific regions, but a dramatic increase of cases has been reported
in the Latin America during the last decade.
The World Health Organization (WHO), and its regional
body in the Americas, the Pan American Health Organization (PAHO), keeps the
dengue infection records for the 35 nations and 9 sub-regions of the territory.
They carry an active surveillance through which they measure the number of
cases reported on each country during each epidemiological week.
The total classic dengue fever cases reported in the
Region were 1,033,417 (16.4/100,000) during the 80s, 2,725,405 (35.9/100,000)
during the 90s, and 4,759,007 (71.5/100,000) during 2000–7. Similarly, the
number of dengue hemorrhagic fever (DHF) cases increased over time from 13,398 (0.2/100,000)
during the 80s, to 58,419 (0.8/100,000) during the 90s, to 111,724
(1.7/100,000) during 2000–7. The DHF cases as a percentage of total dengue
cases also increased from 1.3% to 2.1% to 2.4%. Epidemic cycles were observed
every 3–5 years with an increased frequency of DHF cases and fatalities caused
by dengue during epidemic years. From 1980 through1987, 242 deaths were
reported (1.8% of all DHF cases) compared with 1,391 deaths during 2000–7 (1.2%
of all DHF cases).
The number of countries with an average incidence greater
than 100/100,000 increased from 5 during the 80s to 7 during the 90s, and then
to 15 during 2000–7. During the 27-year study period, Brazil reported the
majority of dengue cases (54.5%) and Venezuela reported the highest number of
DHF cases (35.1%) during the same period. In general, reported cases of both
forms of dengue increased over time in all of the countries of the region, with
the exception of those in the Hispanic Caribbean.
These data constitutes a direct indicator for the rising
incidence and prevalence of dengue in the Region. I couldn’t find any indirect
indicators for measuring dengue prevalence and incidence, but this is pretty
strong data (even though it does not consider all the number of cases which are
not reporter to the local public health institutions), but they do represent
the general tendency considered for this study.
Sources:
Martín, José Luis: The
Epidemiology of Dengue in the Americas Over the Last Three Decades: A Worrisome
Reality; http://new.paho.org/hq/dmdocuments/2010/Jan%202010%20AJTMH%20Dengue%20BZ%20GD%20AB%20OS%20JSL%20OB%20MGG.pdf
World Health Organization, Dengue Alerts, http://new.paho.org/hq/index.php?option=com_moreinfo&moduleid=1011&Itemid=363
World Health Organization, Descripción de la situación epidemiologica
actual del dengue en las Amèricas;
http://new.paho.org/hq/index.php?option=com_content&task=view&id=4494&Itemid=2481
Hi Isabella, good start.
ReplyDeletePlease make sure you check the grammer of the problem statement so it is a complete sentence. Also a couple of things:
Who is affected ?
Are you concerned about Dengue infection, or mortality from dengue ?
Indirect indicators might be related to changes in sanitation in the areas you are looking at, changes in the number or presence of surveillance systems for the infection, or changes in number of vector control programs to control the vector.