Dear Erin,

You raise an important point, but a few comments are needed before answering it.

Prevalence is not a good measure of SAM burden. Incidence would be more appropriate. SAM as indicated by its name is an acute disease and acute conditions are poorly captured by prevalence surveys. As a comparison, you don’t measure the importance of measles or heart diseases as public health problems in a population by doing prevalence surveys, you just count the number of cases, ie you measure incidence. We should do the same for SAM.

SAM prevalence is difficult to measure, as it is statistically a rare event and is submitted to a large margin of error if you don’t use a large sample. Incidence is even more difficult to measure as this can be only measured through a regular surveillance system difficult to set up. So incidence is rarely measured in practice, and prevalence is measured instead. But it is a poor measure of what happens.

There is no reason that CMAM programmes that are only curative can have an effect on SAM incidence. This can be achieved only if these programmes have some preventive component (eg admit for treatment children with a MUAC <120 instead of 115 mm). Curative programmes however can have an effect on mortality even if they have no effect on incidence by reducing case fatality.  

In theory CMAM programmes with a high coverage can have some effect on SAM prevalence even if they have no prevention component (which is not desirable) and no effect on incidence. Prevalence is related to incidence x duration of the disease. When you treat a SAM case, you decrease the duration of the disease and you decrease prevalence even if incidence remains the same. Arguably, you also prevent some deaths, which has an opposed effect on prevalence, as those who die do not appear in prevalence surveys. But overall there should be some reduction of prevalence with a successful CMAM programme. This should be difficult to measure as SAM prevalence itself is difficult to measure for reasons explained above. And of course a reduction of incidence by a preventive component is preferable.

Final comment: the number of SAM cases is usually small compared to total number of malnourished children (MAM + SAM) so CMAM programmes are unlikely to have an effect on overall malnutrition prevalence, which is easier to measure, and is often used to assess the nutritional status of a population.

I hope this helps,

André

As per the global action plan on child wasting, improve treatment of children with wasting is one of the four action areas to reduce prevalence of wasting. As per the framework, the four areas of focus are Reduce incidence of Low brth weight, Improve child health, improve IYCF, and improve treatment of children with wasting. you access the document through the following links

file:///C:/Users/kabebe/Downloads/global-action-plan-child-wasting.pdf