Tropical Health Matters

Bright C. Orji, Charity I. Anoke, William Robert Brieger presented a poster at ASTMH 2024 in New Orleans that analyzed the ability of national surveys to detect health program outcomes.

Intermittent preventive treatment of malaria in pregnant women (IPTp) promotes health of the mother and unborn child. One noteworthy benefit is reduction of low birth weight (LBW, less than 2.5kg). Large survey data sets aid learning about such benefits on a national scale.

We analyzed data from the 2018 Nigeria Demographic and Health Survey (DHS) to document the impact of IPTp on birth weight. Key variables included IPTp which based on national guidelines is given monthly at antenatal clinics from the 13th week, aiming to provide a minimum of 3 doses. DHS obtained this information from women giving birth in the previous two years.

Birth weight included women giving birth in the previous five years. A quarter had a record of newborn weight reported from a health facility.

Since many did not, women were also asked to estimate the size of the baby at birth: very small, smaller than average, average, larger than average, and very large. We combined the latter three categories into “average or larger”.

Of those giving birth in the past 2 years, 23% took only one dose, 24% took 2 doses, while 17% had 3 or more doses. In the broader sample of those giving birth in the previous 5 years 2.8% estimated that their baby was very small.

Among those women with a record of birth weight, 7% were LBW. Preliminary analysis comparing perceived size and IPTp doses found 3% receiving only one dose thought their baby was “very small” at birth, as did 3% of those taking 2 doses and 4% receiving 3 or more.

Among the subset with a recorded birth weight, 9% who took only one dose of IPTp had LBW baby, as did 7% who received 2 doses, and 6% who got 3 or more doses. It appears possible to compare outcomes (LBW) with interventions (IPTp), but data type and availability may limit conclusions.

Even though a smaller subset of women had access to a recorded birth weight (most women delivered outside a health facility), birth weight appears to provide a better indication of IPTp effectiveness than subjective perceptions of child’s size at birth.

The findings even with limitations show the value of national surveys to justify policies protecting pregnant women from malaria.

The World Health Organization has prepared an important document entitled “Health is the Argument for Climate Action: COP29Health is the Argument for Climate Action: COP29 Special Report on Climate Change and Health”. Malaria and other vector borne diseases are highlighted.

The report addresses diseases carried by mosquitoes by stating that, “Climate change increases the transmission of deadly infectious diseases such as dengue, malaria, West Nile virus” and others which are temperature and rainfall dependent. In particular, malaria transmission is intricately connected with temperature and rainfall patterns, and extreme weather events have been shown to cause rapid spikes in cases.”

Climate change not only effects environmentsClimate change not only effects environments where these diseases thrive, but impacts the livelihoods of populations, reducing their ability to pay for prevention and treatment. Migration and displacement also may result increasing vulnerability to disease.

Two of the report’s recommendations have special bearing on malaria. One is the need to “develop and implement innovative financing mechanisms, such as a global health insurance scheme for climate-vulnerable nations” and communities. A second is the importance of “Strengthen(ing) health surveillance systems, particularly in low-income countries, to better track and respond to climate-related health impacts.”

Recognizing the climate dependence of malaria will be a crucial step in eliminating the disease.