Does socio-economic status explain the differentials in malaria parasite prevalence? Evidence from The Gambia
Sheriff T Sonko
1
Malanding Jaiteh
3
James Jafali
2
Lamin BS Jarju
1
Umberto D'Alessandro
2
Abu Camara
5
Musu Komma-Bah
4
Alieu Saho
4
0
17
,
Kanifing
,
The Gambia
1
National Malaria Control Programme
,
Kanifing Institutional Layout, Plot
2
Medical Research Council Laboratories
,
Fajara, Banjul
,
The Gambia
3
Center for International Earth Science Information Network (CIESIN), Columbia University
,
New York
,
USA
4
Gambia Bureau of Statistics, Kanifing Institutional Layout
,
Kanifing
,
The Gambia
5
Islamic Development Bank
,
Jeddah, Kingdom of
Saudi Arabia
Background: Malaria is commonly associated with poverty. Macro-level estimates show strong links between malaria and poverty, and increasing evidence suggests that the causal link between malaria and poverty runs in both directions. However, micro-level (household and population) analyses on the linkages between malaria and poverty have often produced mixed results. Methods: The Gambia Malaria Indicator Survey (MIS) 2010/11 was carried out between November 2010 and January 2011. Laboratory-confirmed malaria and wealth quintiles were used to assess the association of socio-economic status and malaria infection in children and the general population. Simple and multiple logistic regressions and survey data analysis procedures, including linearized standard errors to account for cluster sampling and unequal selection probabilities were applied. Results: Children (six to 59 months) from the second, third, fourth and richest quintiles were significantly less likely to have malaria compared to children from the poorest quintiles. Children (five to 14 years) from the fourth and richest quintiles were also significantly less likely to have malaria compared to those from the poorest quintiles. The malaria burden has shifted from the under-five children (six to 59 months) to children aged five to 14 years. Malaria prevalence was significantly higher in the Central River Region compared to the Upper River Region; and males bear the malaria brunt more than females. Children (six to 59 months) and children (five to 14 years) living in houses with poor walls, floors, roofs and windows were significant associated with higher prevalence of malaria. However, in the general population, only poor wall housing materials were associated with higher prevalence of malaria. Conclusions: Investments in strategies that address socio-economic disparities and improvements in the quality of housing could, in the long term, significantly reduce the malaria burden in the poorest communities.
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Background
The worldwide malaria burden is currently estimated at
about 207 million cases and 627,000 deaths. Sub-Saharan
Africa bears the heaviest brunt, with 90% of all deaths, 77%
among children under-five. Nevertheless, between 2000
and 2012, malaria mortality rates have decreased by 42%
worldwide (by 48% in children under-five) and by 49% in
the African Region (by 54% in children under-five) [1].
Malaria is commonly associated with poverty [2-10].
Macro-level estimates show strong links between malaria
and poverty. For instance, the malaria burden is highest
in the poorest countries, particularly in sub-Saharan
Africa, where poverty is widespread and with little
economic growth over the past quarter century [5,6]. The
gross national product (GNP) in malaria endemic
countries is more than half lower than in non-endemic
countries [6]. The poorest 20% of the worlds population
contribute to 58% of all malaria deaths [11]. Increasing
evidence at macro-level suggests that the causal link
between malaria and poverty runs in both directions [3-6].
A review of micro-level (household and population)
analyses on the link between malaria and poverty has
produced mixed results [12]. Out of nine studies, only two
reported a significant association between malaria and
poverty [12]. Data from 29 demographic and health
surveys (DHS) in 22 countries were used for an
aggregatelevel regional data analysis for West and Central Africa,
and East and Southern Africa, including individual child
and country-by-country analysis. No differences were
found at the household level in the incidence of fever
between the poor and the less poor, though significant
differences were found at more aggregate-levels, i.e.,
country-by-country as opposed to regional-level
analysis [13]. In Ghana, social class was not associated with
risk of malaria infection [14]. In Tanzania, there was no
association between self-reported malaria and
socioeconomic status (SES) but malaria prevalence was
significantly higher among the lower SES individuals [15].
In Nigeria, self-reported malaria or fever was more
frequent among the better-off SES and urban dwellers
[16] though an earlier study showed a heavier malaria
burden among the poor (<US $1/day) compared to the
rich [17]. Contrasting results are function of the
methodology used to measure malaria and poverty. Studies
based on self-reported fever are likely to overestimate
the malaria (...truncated)