Review of schistosomiasis and soil transmitted helminthiasis situation in Ghana sheds light on promising new treatment strategies

September 12th, 2013

It’s hard to keep the conversation polite when the topics of discussion are schistosomiasis (SCH) and soil-transmitted helminths (STH), two of the world’s nastiest neglected tropical diseases (NTDs). So, don’t say you haven’t been fairly warned.

NTD experts work to reshape Ghana’s national treatment strategy for SCH and STH. Photo: Joseph Koroma, FHI360

People get SCH and STH when they come into contact with worm eggs that have been excreted in human feces or urine, which contaminate the soil and water sources near their homes, which are typically located in areas that lack adequate sanitation. They get sick by inadvertently ingesting either the eggs or the larvae when using contaminated water to prepare food or wash their utensils or hands. Or they get sick when larvae in contaminated soil or water penetrate their skin while they work, play, swim or bathe.

SCH (or “snail fever”) and STH (also known as roundworm, hookworm or whipworm, depending on the parasite) are diseases of poverty that  thrive in tropical and sub-tropical areas, most often affecting communities without potable water and adequate sanitation. Chronic SCH and repeated STH infections make people so ill that they can’t work, study, or take care of themselves and their families.  Sometimes, they even die. In children these diseases can cause anemia, stunting and reduced ability to learn–any of which can set them up for a lifetime of poor health and little hope for success, even if they are lucky enough to get treatment for their infection.

In spite of efforts to fight these and other NTDs, SCH and STH continue to make life miserable for many people around the world, especially in African countries such as Ghana. All 170 of Ghana’s health districts (HD) are endemic for both diseases, even though the country has been providing its people with treatments in all 170 HDs since 2008–at least annually for STH, plus 70 HDs receive additional lymphatic filariasis treatments with ivermectin and albendazole, which are also effective against STH; and at least once every three years (depending on baseline prevalence in each HD, in accordance with previous WHO treatment guidelines) for SCH.

Although it has certainly gone a long way toward helping prevent and cure infections, the current treatment regimen hasn’t been enough to rid Ghana of STH and SCH entirely. But the good news is that this may soon change, thanks to a few recent events.

Ghana’s NTD Program Manager outlines the country’s current STH and SCH situation. Photo: Joseph Koroma, FHI360

First, the World Health Assembly passed a new resolution (WHA65.21) a little over a year ago, calling for the elimination of SCH as a public health problem, which prompted the World Health Organization (WHO) to create new treatment guidelines to redouble efforts to interrupt disease transmission in endemic countries. Then just this summer, Ghana’s NTD experts teamed up with partners to conduct an internal review of the parasitological and treatment data for SCH and STH and to redefine the country treatment strategy for both diseases.

The review took shape in the form of a two-day workshop on June 26-27, 2013, and included a systematic, detailed review of programmatic issues, as well as a thorough assessment of parasitological data, treatment data and all program activities relating to SCH and STH.  Following this review and assessment, the experts devised recommendations for parasitological monitoring of both diseases and realigning the national treatment strategies with the new WHO guidelines.

After studying the new WHO guidelines and WHA resolution as well as reviewing and discussing the parasitology and treatment data, the thirteen participating experts from Ghana’s national NTD Program (NTDP), the country’s School Health Education Program, the Volta Region Authority (VRA), the Noguchi Memorial Institute of Medical Research (NMIMR), Catholic Relief Services Ghana and the END in Africa project, went to work on drafting their recommendations for the way forward.

Five key recommendations emerged from their work:

1. Since SCH and STH treatments had been given to children while they were at school, the program had not been reaching school-aged children (SAC) who did not attend school. To improve coverage, the NTDP will need to use community volunteers to identify SAC who do not go to school within the targeted communities during future mass treatments of at-risk populations.
2. The NTDP’s baseline and study site parasitological data is of sufficiently high quality and will be useful for monitoring the impact of ongoing mass treatments of at-risk populations.
3. Several steps need to be taken in Ghana’s NTDP over the next few years to set the country on the path toward doing its part to achieve the goal set forth in Resolution WHA65.21–namely, to eliminate SCH as a public health problem and interrupt its transmission in Ghana.  First, districts with moderate (10%-49%) or high (≥50%) SCH prevalence will need to treat entire at-risk communities, rather than just SAC. However, districts with low SCH prevalence (<10%) can safely continue treating SAC alone.  The program will implement these changes over the next 2 years.
4. The NTDP will conduct an impact assessment survey in 2015, and the results will be used to realign district treatment strategies, when necessary. For example, if the survey shows that prevalence has dropped from moderate to low in a particular district, then the treatment strategy for that district will be adjusted accordingly.
5. The NTDP will continue to collaborate with the NMIMR and the VRA on research around SCH and STH; and students will be encouraged to select topics relating to SCH and STH for their theses. This will permit the NTDP to support in-depth research in areas identified as  needing special attention.