Cryptosporidium Outbreak in Milwaukee

Cryptosporidium Outbreak in Milwaukee

Introduction

The characteristics of a pathogen have a great impact on their ability to spread, the speed of spread, and mitigation strategies and mechanisms to eliminate them. The Milwaukee cryptosporidium outbreak infected 403,000 residents and people visiting the town within two weeks. Additionally, the pathogen killed 69 people, most of them (93%) who were HIV/AIDS infected individuals. Cryptosporidium is both symptomatic and asymptomatic.  The symptoms in people infected include watery diarrhoea containing mucus without leukocytes or blood, dehydration, stomach cramps, and high fever. The following analysis will entail a strategic analysis of the pathogen through evaluating the impacts that it has on society and the efficiency of attempted prevention approaches.

1. Risk Characterization of Pathogen
2. Type of Pathogen and its characteristics

For the case of Milwaukee cryptosporidium outbreak, the pathogen involved was a pathogen. The key characteristic that led to the individual classification of cryptosporidium as a pathogen is that it involved transmission through water. Water and food are the major transmission elements of bacteria. Unlike viral infections that are transmitted through body fluids or air particles, bacterial infections are water-transmitted (Iqbal, Khalid & Hira, 2011). Contamination of one of the two water treatment plants resulted in the transmission of cryptosporidium as revealed in the characteristics seen in symptomatic infected individuals. The characteristics that led to the identification of the pathogens in the infected people in Milwaukee are the symptoms shown. The main characteristic was watery diarrhoea that contained mucus without leukocytes or blood. Other symptoms included dehydration, stomach cramps, and high fever. These are different from viral infections that show characteristics such as coughing among others (Pendar, & Páscoa, 2020).

2. Negative Outcome due to the Pathogen to the Community, and Transmission Methods based on Composition

The major negative impact of cryptosporidium is mortality levels that affect both the young and old, especially the immunocompromised population. In Milwaukee, 69 deaths were resulting from the outbreak, and 93% were HIV-infected individuals (Solo‐Gabriele & Neumeister, 1996). Another negative impact is the high cost required in the treatment of infected people and investment for control mechanisms. For people infected with the pathogen, the costs involved include medical costs, medication costs, and outpatient and ambulance costs. Other effects included productivity losses for sick individuals and their caregivers. Cryptosporidium is transmitted from one individual to the other when it is shed to the environment; cryptosporidium can be found in food, water, soil, and contaminated surfaces that are contaminated with contaminated faeces. These means of transmission are appropriate because the parasite exists for a long time and is resistance to chlorine-based disinfectants due to a hard outer shell that enables it to survive for longer in harsh environment (Collivignarelli et al., 2018). Also, cryptosporidium infection at early childhood is associated with significant impairment in growth, somatic fitness, and intellectual aptitudes.

1. Ecological Perspectives
2. Individual Level

At this level, different individuals have diverse immune system and strength to help prevent succumbing from the disease. The most affected people are those who are immunocompromised.  The pathogen easily results in the death of those with weak immunity because their immune system is easily further weakened because of the already weak immune system. Also, the attitude towards drinking safe or unsafe water will determine how well individuals protect themselves from Cryptosporidium. Policies can include proper diet for immunocompromised individuals to help strengthen their immune system and educating people on the pathogen and importance of proper water treatment methods such as boiling.

2. Relationship Level

The pathogen transmits from individual to others through faecal matter, water, and food. An efficient control method is preventive policies that prohibit waste disposal into water sources and other areas where people live including farms. Proper cleaning and washing of foods are also important as well as hand washing before eating. Also, boiling water and other proper treatment of water through methods that break the shells of the Cryptosporidium is essential.

3. Community Level

Herd immunity involves the resistance to the spread of a contagious disease within a population that results if a sufficiently high proportion of the population is immune to the disease, especially through vaccination (Vyas, Kadam & Mashru, 2020). Thus, the best way to increase the immunity of the community is through vaccination. Though there is no vaccine for Cryptosporidium, use of Cp23 and Cp15 surface proteins of sporozoite of C is an important community-level prevention measure. Also, water treatment from the source is an adequate preventive measure.

4. Societal Level

The society should be educated on the importance of information disclosure. The case in Milwaukee for instance caused many infections because the contaminated water treatment plant did not report queries presented on the possibility of contamination. Also, people should seek immediate medical support if they feel unwell. The society should avail medical services to all people especially those with the weak immune system.

Appendix A illustrates the Social-Ecological Mosel (SEM)

5. One Health

The collaborative efforts of multiple disciplines will help prevent contamination by the cryptosporidium pathogen. The strategies should work together at a local, national, and global level to achieve optimum health for people, animals and the environment. Health and prevention will be achieved through working together of human beings, animals, and the environment because they are the means of spreading; they are also preventive means. Appendix B presents the One Health summary.

1. Pathogen Prevention and Control
2. Mitigation Strategies

Vaccination is a strategy that has worked efficiently in preventing other bacterial diseases. Thus, it is a goal that health experts are aiming at.  Vaccines help in preventing infection which ensures a health community. The vaccine aims at reducing disease and shedding of cryptosporidium oocysts for both animals and human. Though an efficient strategy, the vaccine is not yet developed.

A second strategy that has worked for Milwaukee is Application of technological progress to assess water safety and reduce the amount of defectively filtered water to the people. The technology has seen Milwaukee ranked among the cities with most clean water. Technology also is used to assess the safety of water at the source and finished for the presence of cryptosporidium. They function through identifying the presence or absence of the pathogen in water before people consume it. Though these methods are efficient, technology can fail and this could lead to transmission of pathogens to people (Mack & Choffnes, 2009).

The WHO ranked house water treatment as the most appropriate water treatment methods against cryptosporidium. Boiling water and the use of chlorine is another method recommended used to help mitigate cryptosporidium. Boiling water and treatment with chlorine is an effective method used to kill water microorganisms. However, WHO outlined that chlorine water treatment is not effective because of the hard shell of the cryptosporidium pathogen (Peletz et al., 2013). Thus, it is important to use boiling for safer water.

Another strategy is integrated genotyping to enable detection in human and animals. It is done through the use of Multilocus fragment typing (MLFT), which gives efficient differentiation because of its type ability, specificity, accuracy, accuracy, and aptitude to genotypically distinguish bovine-derived Cryptosporidium parvum (Innes et al., 2020). These will help in tracking, surveillance, and epidemiology (Innes et al., 2020). However, the method does not prevent infection but rather identifying the already infected individuals.

Another strategy is treating contaminated cryptosporidium (Innes et al., 2020). Though the method will prevent contamination to other people and animals, the method is difficult to use in asymptomatic infections. Additionally, it would be hard to differentiate between contaminated and non-contaminated livestock and human waste.

1. Pathogen Agency
2. Difference between how biological, chemical and physical agents affect human health

Biological

The biological factor that has made prevention strategies problematic is the incapacity to constantly propagate the parasite in vitro. A second biological challenge issue is the incapacity to cryopreserve the pathogen the way most pathogens are eliminated (Tzipori & Ward, 2002). These are revealed in the absenteeism of properly-characterized reference strain of the bacteria infecting diverse species, sub-species, and classes (Tzipori & Ward, 2002). Thus, human beings continue to get infected by the pathogen.

Chemical

According to Liu et al. (2010), cryptosporidium contains a fluffy layer of glycoproteins, which makes resistance to chemicals such as chlorine used to kill it.

Physical

Cryptosporidium has a protein-lipid–carbohydrate matrix and a thick wall comprising of inner and outer oocyst walls. It is only the thick wall that sheds to the environment. Thus, it is easy to infect human beings even when prevention methods are applied. Also, the pathogen has obscure internal organs, which makes it more penetrative into the human track causing infection. The ability for infection is further increased by the hallmark feature of mature oocysts, which has four sporozoites but no sporocyst (Feix et al., 2020).

2. Mitigation Strategies

Different mitigation strategies differ on how they work based on the biological, chemical, and physical characteristics of agents. The strategies used to prevent transmission of diseases are based on the composition of the pathogens. Mitigation based on physical characteristics can involve weakening the hard shell of the pathogen. For instance, prevention of cryptosporidium is possible by boiling water to weaken the shell. Also, vaccines can help remove the fluffy layer of glycoproteins component of the pathogen, hence eliminating it or subjecting it to other agents of prevention.

1. Program Strategies
2. Role of Cryptosporidium and Related Features in Health Programs Targeting it

According to Mohammed, Degefu & Jilo (2017), cryptosporidium can survive for several months without loss of its infectivity because of its resistance to a harsh environment. Due to these adverse features of the pathogens, there is no effective therapeutic agent for the control and mitigation of cryptosporidium. The disease continues to be prevalent especially in developed countries and it is the main source of diarrhoea in children. Programs set to mitigate it include improved water management practices like what is done in Milwaukee. Also, creating awareness is an important strategy for the community. Another program is preventing the disposal of waste products into lakes, streams, and rivers. A third strategy is to boil or pasteurize water before consumption. Other programs include further studies to help find a vaccine against the bacteria (Mohammed, Degefu & Jilo, 2017).

2. Public Health programs Prevention and Control Strategies, Locally and Globally

Mitigation strategies for cryptosporidium measures are extensive both at a local and international level. The Center for Disease Control (CDC) recommends good hygiene practices which include washing hands especially in main times when one can spread the infection. CDC argues that alcohol-based sanitizers are not effective in preventing infections. Another strategy involves excluding sick children showing diarrhoea symptoms from childcare environments until the diarrhoea ceases. Prevention measures are also taken against swimming when sick and showing diarrhoea symptoms. Avoid contaminated water and foods (Parasites, 2019). The One Health program is efficient because cryptosporidium affects both animals and human beings (Innes et al., 2020).

1. Special Considerations
2. Important Considerations for Mitigation of Cryptosporidium

According to the World Health Organization, cryptosporidium should remember that the pathogen is extremely resistant to chemical disinfection. Thus, they should take more precaution in the methods they use and try to avoid using chemical control measures that are used for other pathogens. Also, the pathogen is persistent in the environment which means it can be infective even after some months. A third consideration is the extremely small size of cryptosporidium that makes physical control measures relatively ineffective except for water boiling. People should also recall that the pathogen is transmissible by both human and animals. Another consideration is that oocyst shedding occurs in multiple numbers. Lastly, cryptosporidium does not require maturation (Medema et al., 2006).

2. Special Precautions when Preventing Cryptosporidium

Because the pathogen is infective even for a long time, it is important to avoid contact with faeces and use protective gears like disposable gloves during the mitigation process. Also, it is important to constantly wash hands to prevent infection. Isolating the infected individuals from the non-infected ones is also another precaution in preventing spread. Cleaning animal faeces and appropriate disposal is also essential. Additionally, people should wear protective gears when handling infected animals and treating them.

Conclusion

Though there are several strategies put in place to prevent infection by cryptosporidium, infection rates continue to be high especially in children in developing nations. Then WHO and CDC among other programs provide measures to prevent infections. Cryptosporidium has several physical, biological, and chemical adaptations that make prevention hard. Use of chlorine does not prevent contamination by pathogens. Precautions should be taken to control increased infections among people and animals. An efficient way of preventing further spread is the One Health initiative.

References

Centers for Disease Control and Prevention (CDC) (n.d). The Social Ecological Model:  A Framework for Prevention. Retrieved from http://www.cdc.gov/violenceprevention/overview/social-ecologicalmodel.html

(Retrieved October 14, 2020).

Collivignarelli, M. C., Abbà, A., Benigna, I., Sorlini, S., & Torretta, V. (2018). Overview of the main disinfection processes for wastewater and drinking water treatment plants. Sustainability, 10(1), 86.

Feix, A. S., Cruz-Bustos, T., Ruttkowski, B., & Joachim, A. (2020). Characterization of Cystoisospora suis sexual stages in vitro. Parasites & vectors, 13(1), 1-13.

Innes, E. A., Chalmers, R. M., Wells, B., & Pawlowic, M. C. (2020). A one health approach to tackle cryptosporidiosis. Trends in parasitology, 36(3), 290-303.

Iqbal, J., Khalid, N., & Hira, P. R. (2011). Cryptosporidiosis in Kuwaiti children: association of clinical characteristics with Cryptosporidium species and subtypes. Journal of medical microbiology, 60(5), 647-652.

Kolff, C. A., Scott, V. P., & Stockwell, M. S. (2018). The use of technology to promote vaccination: A social ecological model based framework. Human Vaccines & Immunotherapeutics, 14(7), 1636-1646.

Liu, Y., Kuhlenschmidt, M. S., Kuhlenschmidt, T. B., & Nguyen, T. H. (2010). Composition and conformation of Cryptosporidium parvum oocyst wall surface macromolecules and their effect on adhesion kinetics of oocysts on quartz surface. Biomacromolecules, 11(8), 2109-2115.

Mack, A., & Choffnes, E. R. (Eds.). (2009). Global issues in water, sanitation, and health: workshop summary. National Academies Press.

Medema, G., Teunis, P., Blokker, M., Deere, D., Davison, A., Charles, P., & Loret, J. F. (2006). WHO guidelines for drinking water quality: Cryptosporidium. WHO, New York, 138.

Mohammed, A., Degefu, H., & Jilo, K. (2017).  Cryptosporidium and Its Public Health Importance.

Parasites, C. D. C. (2019). Cryptosporidium (also known as “Crypto”). Retrieved from https://www.cdc.gov/parasites/crypto/gen_info/prevention-general-public.html

Peletz, R., Mahin, T., Elliott, M., Montgomery, M., & Clasen, T. (2013). Preventing cryptosporidiosis: the need for safe drinking water.

Pendar, M. R., & Páscoa, J. C. (2020). Numerical modeling of the distribution of virus carrying saliva droplets during sneeze and cough. Physics of Fluids, 32(8), 083305.

Solo‐Gabriele, H., & Neumeister, S. (1996). US outbreaks of cryptosporidiosis. Journal‐American Water Works Association, 88(9), 76-86.

Tzipori, S., & Ward, H. (2002). Cryptosporidiosis: biology, pathogenesis and disease. Microbes and Infection, 4(10), 1047-1058.

Vyas, J., Kadam, A., & Mashru, R. (2020). The Role of Herd Immunity in Control of Contagious Diseases. Int. J. Res. Rev, 7, 12.

World Health Organization. (2019). Taking a Multisectoral One Health Approach: A Tripartite Guide to Addressing Zoonotic Diseases in Countries. Food & Agriculture Org..

References

Appendices

Appendix A: The Social-Ecological Model

Adapted from the Centers for Disease Control and Prevention, (2020)

Appendix B: One Health (WHO, 2019)

Appendix C:Life Cycle and Transmission of Cryptosporidium

Figure 1 Life cycle and transmission of Cryptosporidium spp. (Image by Thamonphan Wimonsrinarachai

A detailed account of the life cycle starts from sporulated oocyst (which is rarely morphometric differences among different species) released by the infected host. After that, vertebrate host ingests sporulated oocyst through consumption of contaminated food or drink, and the process of excystation will occur to release 4 infectious sporozoites. This progression occurs in the gastrointestinal tract triggered by CO₂, the temperature of 37°C, pancreatic enzymes, and pH acidic of bile salts