Free-Living Amoebae in Iran’s Water: Review – BIOENGINEER.ORG

Report on the Prevalence of Free-Living Amoebae in Iranian Water Sources and Implications for Sustainable Development Goals

Executive Summary

A systematic review and meta-analysis published in Acta Parasitologica provides a comprehensive assessment of the prevalence of pathogenic free-living amoebae (FLA) in Iran’s water sources. The findings indicate widespread contamination across tap, recreational, and natural water bodies, posing a significant public health risk. This report analyzes these findings through the lens of the United Nations Sustainable Development Goals (SDGs), highlighting critical challenges to achieving SDG 3 (Good Health and Well-being) and SDG 6 (Clean Water and Sanitation), and noting intersections with SDG 11 (Sustainable Cities and Communities) and SDG 13 (Climate Action).

Key Findings and Public Health Ramifications

Widespread Contamination and Pathogenic Risk

The meta-analysis synthesizes data from numerous regional studies, revealing a pervasive presence of FLA. The distribution and concentration of these organisms are influenced by geography, season, and water type.

• Pathogenic Genera Identified: The presence of clinically significant amoebae, including Acanthamoeba (associated with keratitis), Naegleria fowleri (the cause of primary amoebic meningoencephalitis), and Balamuthia, was confirmed in various water sources.
• Vulnerable Populations: Immunocompromised individuals and children are at heightened risk of severe, often fatal, infections from these waterborne pathogens.
• Vectorial Capacity: FLAs can act as “Trojan horses,” harboring and protecting other pathogens like Legionella pneumophila from disinfection processes, thereby complicating broader infection control efforts.

Inadequacies in Water Management and Surveillance

The study underscores systemic weaknesses in current water safety frameworks that fail to adequately address the threat posed by FLA.

• Treatment Ineffectiveness: The cystic forms of FLA exhibit high resistance to conventional water treatment methods, including chlorination, allowing them to persist in treated water supplies.
• Surveillance Gaps: Research and monitoring efforts are unevenly distributed, with rural and underserved regions often overlooked despite showing high rates of FLA detection. This disparity points to an urgent need for a coordinated, nationwide surveillance strategy.
• Technological Advancement: While molecular methods like PCR have improved detection accuracy, their application is not yet standard, leading to potential underestimation of the problem in historical and ongoing assessments.

Alignment with Sustainable Development Goals (SDGs)

SDG 6: Clean Water and Sanitation

The prevalence of FLA directly undermines the core objective of SDG 6, which aims to ensure the availability and sustainable management of water and sanitation for all. The findings present a direct challenge to Target 6.1: achieving universal and equitable access to safe and affordable drinking water.

1. Compromised Water Safety: The persistence of pathogenic amoebae in treated tap water demonstrates that current safety standards are insufficient to protect public health, failing the “safely managed” criteria of SDG 6.
2. Infrastructure and Equity Deficits: The higher prevalence in untreated surface water, relied upon by many rural communities, highlights a critical equity gap in access to safe water infrastructure.
3. Need for Modernized Standards: The research serves as a call to action for regulatory bodies to update water quality standards to include monitoring and mitigation strategies for protozoan pathogens like FLA.

SDG 3: Good Health and Well-being

The health impacts of FLA contamination are a direct impediment to achieving SDG 3, particularly its targets on ending epidemics and reducing mortality from environmental pollution.

• Threat of Water-Borne Disease: The presence of FLA contributes to the burden of water-borne diseases, challenging Target 3.3 (end the epidemics of…water-borne diseases). Infections, while rare, have high mortality rates and require specialized clinical intervention.
• Environmental Health Risks: Contamination of water sources represents a significant environmental health hazard, directly relevant to Target 3.9 (substantially reduce the number of deaths and illnesses from…water…contamination and pollution).
• Ocular Health: The link between Acanthamoeba in water and keratitis, especially among contact lens users, is a specific public health issue that requires targeted awareness campaigns to protect community well-being.

Intersecting Goals: Climate Action (SDG 13) and Sustainable Communities (SDG 11)

The study’s implications extend to broader environmental and urban development goals. The report notes that rising global temperatures, a focus of SDG 13 (Climate Action), may expand the ecological niches for thermophilic amoebae like Naegleria fowleri, turning previously safe water bodies into high-risk areas. Furthermore, ensuring the safety of urban tap water is fundamental to SDG 11 (Sustainable Cities and Communities), as reliable access to safe water is a cornerstone of resilient and healthy urban environments.

Recommendations and Strategic Outlook

Policy and Infrastructure Recommendations

To address the challenges identified and advance progress toward the SDGs, the following actions are recommended:

1. Enhance National Surveillance: Implement a coordinated, nationwide monitoring program using modern molecular techniques (e.g., PCR) for accurate and rapid detection of FLA in all water source types.
2. Invest in Advanced Water Treatment: Promote research and investment in new disinfection technologies capable of inactivating or removing resilient amoebic cysts from the water supply.
3. Update Water Safety Regulations: Revise national water quality standards to incorporate specific limits and testing protocols for pathogenic free-living amoebae.
4. Promote Public Health Education: Launch targeted public awareness campaigns regarding the risks associated with recreational water use and proper contact lens hygiene to prevent infections.

Future Research Directions

Continued research is essential for developing evidence-based policies and interventions.

• Predictive Modeling: Develop models based on environmental parameters (temperature, pH, nutrient levels) to identify potential FLA hotspots and inform preventive measures.
• Clinical Diagnostics: Improve and disseminate rapid diagnostic tools for clinical settings to ensure timely and accurate identification of amoebic infections, thereby improving patient outcomes.
• Interdisciplinary Collaboration: Foster collaboration between environmental scientists, microbiologists, public health officials, and clinicians to create integrated strategies for risk mitigation.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

1. SDG 3: Good Health and Well-being
   • The article’s central theme is the public health threat posed by free-living amoebae (FLA) in water sources. It discusses severe and often fatal infections like keratitis and those caused by Naegleria fowleri (the “brain-eating amoeba”), directly linking water contamination to human health and disease. The text emphasizes the vulnerability of immunocompromised individuals and children, reinforcing the connection to public health outcomes.
2. SDG 6: Clean Water and Sanitation
   • The research fundamentally assesses the quality of various water sources in Iran, including tap water, lakes, and rivers. It highlights the “pervasive presence of FLA” and reveals that “conventional water treatment methods may not always effectively eliminate these resilient organisms.” This directly addresses the challenges of ensuring safe drinking water and managing water quality.
3. SDG 11: Sustainable Cities and Communities
   • The study analyzes contamination in “urban tap water supplies” and points to “water infrastructure” as a critical factor in FLA prevalence. This connects the issue to the provision of safe and basic services within cities and communities, a core component of SDG 11.
4. SDG 13: Climate Action
   • The article explicitly links climate change to the expanding threat of FLA. It states, “Increasing temperatures and fluctuating rainfall patterns potentially expand the ecological niches inhabitable by thermophilic species like Naegleria fowleri.” This highlights the need for adaptive water safety management in response to climate-related hazards.

2. What specific targets under those SDGs can be identified based on the article’s content?

1. Under SDG 3 (Good Health and Well-being):
   • Target 3.3: By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases. The article directly addresses this by focusing on pathogenic amoebae that cause water-borne diseases and calls for measures to prevent and control these infections.
   • Target 3.d: Strengthen the capacity of all countries, in particular developing countries, for early warning, risk reduction and management of national and global health risks. The study’s call for “coordinated nationwide monitoring protocols,” “improved diagnostic acumen,” and “public awareness campaigns” aligns perfectly with this target.
2. Under SDG 6 (Clean Water and Sanitation):
   • Target 6.1: By 2030, achieve universal and equitable access to safe and affordable drinking water for all. The finding that FLA are present in tap water and are resistant to conventional treatment directly challenges the “safety” aspect of drinking water supplies.
   • Target 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally. The presence of pathogenic amoebae is a form of biological pollution, and the article’s findings underscore the need to improve water quality by removing these contaminants.
3. Under SDG 11 (Sustainable Cities and Communities):
   • Target 11.5: By 2030, significantly reduce the number of deaths and the number of people affected and substantially decrease the direct economic losses relative to global gross domestic product caused by disasters, including water-related disasters, with a focus on protecting the poor and people in vulnerable situations. Widespread disease outbreaks from contaminated municipal water can be considered a water-related disaster, and the article’s focus on risk mitigation for vulnerable populations supports this target.
4. Under SDG 13 (Climate Action):
   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries. The article’s recommendation for “adaptive water safety management and surveillance systems that can respond dynamically to environmental changes” is a direct response to the climate-related hazard of expanding pathogen niches.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

1. Prevalence of FLA in Water Sources:
   • The meta-analysis itself provides a baseline measurement of FLA prevalence across different water types (tap, recreational, natural). Tracking these prevalence rates over time would serve as a direct indicator of water quality (relevant to Target 6.3) and the safety of drinking water (Target 6.1).
2. Effectiveness of Water Treatment Technologies:
   • The article states that FLA cysts show “remarkable resistance to chlorination.” An indicator of progress would be the development and implementation of new disinfection technologies capable of eliminating these resilient organisms, and the percentage of water systems using such effective methods (relevant to Target 6.1).
3. Incidence of Water-borne Amoebic Infections:
   • The article mentions specific diseases like Acanthamoeba keratitis. A key public health indicator would be the number of reported cases of such infections. A reduction in incidence would signify progress towards Target 3.3.
4. Establishment of Surveillance and Monitoring Systems:
   • The study identifies “gaps in surveillance and reporting” and calls for “coordinated nationwide monitoring protocols.” The establishment and operational capacity of such systems would be a clear indicator of strengthened health risk management (relevant to Target 3.d).
5. Implementation of Public Awareness Campaigns:
   • The article highlights the “necessity for public awareness campaigns about safe water practices.” The number, reach, and effectiveness of these campaigns would be a measurable indicator of proactive public health efforts (relevant to Target 3.d).

4. Summary Table of SDGs, Targets, and Indicators

Source: bioengineer.org