Effect of mesophilic anaerobic biodigestion on taenia solium EGG survival, viability, and infectivity: an approach for future implementation to control helminth infections

The National Institute of Allergy and Infectious Diseases (NIAID) awarded a $134,067 Project Grant under the Allergy and Infectious Diseases Research program (CFDA 93.855) to Asociación Benéfica Prisma (Prisma), a Peruvian non-profit organization, effective September 11, 2025, with a completion date of August 31, 2030. The award supports research investigating the effect of mesophilic anaerobic digestion (MAD) on the survival, viability, and infectivity of Taenia solium eggs as a mechanism to enhance the biosafety of biodigester systems used in low- and middle-income countries. MAD systems process fecal waste to produce cooking fuel and nutrient-rich biosolids for agricultural use, offering significant sanitation and economic benefits to rural communities; however, the systems pose health risks if they do not adequately eliminate parasitic helminths.

The funded research will conduct experimental studies to evaluate egg survival and viability under incremental MAD exposure durations, assess infectiousness through animal infection studies and tissue analysis, and generate data to support future optimization and community-level interventions. Prisma will perform fieldwork, laboratory research, and scientific analysis to determine whether MAD systems effectively destroy T. solium eggs and, if not, identify modifications to maximize egg killing. The ultimate goal is to establish evidence-based modifications to MAD systems that can be evaluated as public health interventions to control helminth infections in rural agricultural regions where such systems could provide the greatest impact on sanitation infrastructure and disease control.

Abstract

Mesophilic anaerobic digestion (MAD) is a cost-effective technology used for household waste treatment and renewable energy production in low- and middle-income countries. IT involves the use of mesophilic anaerobic digestion to process fecal waste, producing gas that can be used as cooking fuel. Additionally, the biosolids and bioliquids produced as byproducts are nutrient-rich and can be used as soil and foliar fertilizers, making MAD systems an attractive option for rural communities lacking sanitation and energy infrastructure. Despite their advantages, biodigesters can pose significant risks to human health. While previous studies have reported adequate biosafety of the effluents, they have primarily focused on bacterial pathogens, which are relatively easy to destroy. The highly pathogenic helminth species, such as taenia solium, which can lead to devastating infections of the central nervous system if the eggs are ingested, have largely been ignored. The transmission of T. Solium primarily occurs in rural agricultural regions, which are the same regions where MAD systems could provide the greatest sanitation and economic benefits. There is an urgent need to determine whether MAD systems destroy T. Solium eggs and, if not, how to optimize EGG killing. To this end, experiments will be conducted to evaluate the survival and viability of eggs with incremental duration of exposure to the MAD system. The infectiousness of eggs will be evaluated by feeding them to pigs and conducting necropsies to detect the presence of parasite cysts in muscle tissue. The main future goal is to modify the MAD systems to maximize EGG killing and then evaluate these systems in a community setting as an intervention to control helminths. If successful, this system will not only improve hygiene in rural endemic areas but also positively impact the environment by reducing the use of firewood as cooking fuel and decreasing indoor smoke that affects lung health, particularly among women. Most of my research is related to evaluating the transmission dynamics of T. Solium. In recent years, we have learned about the behavior of this parasite in endemic areas such as the northern and highland regions of peru and have developed transmission models that help US understand how this parasite can return to previous levels after interventions that cannot be applied permanently. In general, my interest as an early career researcher is to assess the impact of diseases both in silico and in the field and to focus scarce resources on developing interventions with high public health impact.