The Cholera epidemic of 1991-1993

Research Questions/Intro

https://www.pexels.com/photo/person-cleaning-hands-under-water-66346/

For this research kit assignment, I examined the cholera epidemic that affected Latin America from 1991 to 1993, and determined why cholera was able to spread as quickly as it did. Using primary and secondary sources, my goal is to find out how this disease was easily able to spread throughout all of Latin America, and determine how a city can better prepare for a public health crisis, specifically one involving waterborne illnesses like cholera. I also wanted to focus to on how different governments react to public health crises, with the COVID pandemic reminding countries everywhere that preparation is needed to endure a health crisis of this nature. My research questions for this assignment are: 

• What are the most effective prevention methods of spreading waterborne diseases in Latin American cities?
• How has cholera so easily spread throughout Latin America?
• Why and where in Latin America was water quality poor to the degree that it faciliated the spread of cholera in the 1990s?

ee i Narrative/Overview

 The Covid-19 pandemic shined a light on the globe’s preparedness to handle a massive public health crisis, and ensured that countries around the world need to be better equipped to handle the repercussions that come with these crises. However as the Covid pandemic continued, it was clear that it was affecting some countries more severely than others. With the implementation of the vaccine, along with other counter–measures, the virus is becoming more manageable. Similarly, the cholera pandemic of the early 1990s severely impacted Latin America, and exposed the lack of preparedness in certain Latin American countries, who hadn’t experienced a cholera outbreak since the early 1900’s. Cholera is a waterborne disease that is caused by ingestion of contaminated food or water infected with the Vibrio cholerae bacterium. Symptoms take anywhere from 12 hours to 5 days to show on an infected person, and can kill the individual if not treated immediately. Those infected with cholera will likely experience severe diarrhea and dehydration, while those with some extreme cases of cholera have reported shock and seizures. Since the primary source of transmission of the disease is poor water quality, a cholera outbreak is often an indicator of poor city development and inequity.

The disease initially struck the coast of Peru, and then went on and spread to Ecuador and Colombia, eventually spreading throughout Latin America in the ninteenth century. More recently, nearly a million cases were reported throughout all of Latin America, with Peru experiencing the most cases of any country from 1991 to 1993. As the cases and fatalities began to increase, officials for the Pan American Health Organization (PAHO) began to conduct investigations for potential causes for the epidemic, focusing on the poor water supply for the countries most affected by cholera at the time. It was eventually determined that the water supply was inadequately treated, and that the root of the cholera epidemic stemmed from the poorly handled water supply. It’s difficult to determine where exactly in Peru the epidemic started, but researchers have determined several potential theories, including unwashed fruits and vegetables from local food vendors, contaminated food and ice, ballast water discharge, and contaminated drinking water. Through these methods, the disease was easily transported from one person to the next until the PAHO carried out several counter-measures, including chlorination. Chlorine is extremely effective in eliminating the cholera disease from the water supply, and it was far and away the least costly disinfection method.

While some countries were hesitant to implement chlorination, it proved to be effective in eradicating cholera, as it was consistently found to be the most reliable and cheapest way to clear the disease. Contaminated food products were another major source of transmission, and officials of the PAHO began to investigate prevention methods in order to restore the water quality and healthy fish supply. There’s a South American custom of washing and cleaning fish in the ocean before selling them to customers, and with the poor quality of water, combined with many harmful species of plankton lurking in South American waters, this practice was found to be a major culprit for the spread of cholera, and the PAHO began conducting research. It was found that by cooking the fish at 48° C or higher, the Vibrio cholerae bacterium would be successfully eliminated, thus making the fish products safe for consumption. 

 This research kit focuses on the cholera epidemic of 1991-1993. Intriguingly,  Uruguay was the only country in Latin America that did not report any cases of cholera. Unfortunately, I couldn’t find any information to offer an explanation as to why Uruguay didn’t report any cases, as the sources I looked at for this assignment didn’t offer any insight about this. A common thread in the sources I examined was that since the cholera epidemic began in Peru, most of these sources solely focused on Peru, and how the country changed as a whole due to the public health crisis, which made it difficult to find data for all Latin American countries. Of all the sources I looked at for this project, I found that Fred Reiff’s firsthand account of the cholera epidemic to be the most helpful since he was a PAHO official during the cholera epidemic, and his unique perspective provided some useful information for my research kit, including that chlorination was the most effective and cost-efficient method of prevention at the time, as well as providing key insight into the resistance movements that started to form in response to the PAHO introducing chlorination to restore the water supply.

It’s important to note that many Latin American countries, especially Peru, had perfect hospitable conditions for a health crisis involving waterborne illnesses like cholera, since the quality of the water supply in these countries were lacking from the get go, and stayed this way years before the onset of the epidemic. This epidemic was the result of a combination of unfortunate factors, which were ill-fated preexisting conditions, and misguided leadership. 

Primary Sources Annotated Bibliography

Reiff, Fred. “The Latin American Cholera Epidemic of the 1990’s: My View from the Inside.” Water Quality and Health Council, https://waterandhealth.org/safe-drinking-water/latin-american-cholera-epidemic-1990s-view/

In this article for the Water Quality and Health Council, Fred Reiff offers his first-hand account of the cholera epidemic that swept through Latin America in the 1990’s. Reiff served as an official for the Pan American Health Organization (PAHO), which is an office within the World Health Organization. Reiff was tasked with assisting the PAHO in preventing the spread of waterborne illnesses throughout Latin America. The PAHO began to implement chlorination as their main source of prevention against cholera. Reiff notes that a resistance began to form in response to the chlorine tests of the water supply, and this resistance stemmed from concern over the public’s exposure to disinfection byproducts (DBP’S), which are essentially small compounds of chlorine and other matter in water. Reiff notes the drastic difference in a person’s health between contracting cholera and potentially consuming a DBP. Despite DBP’s being far less harmful to the body compared to cholera, the concern over ingesting them began to increase, with Reiff stating that some members of the PAHO feared they would be sued if they went ahead with the chlorination of the water. Reiff concludes by stating that the cholera epidemic of the early 1990’s should serve as a wake up call to these countries so that a similar event can’t repeat. 

“Epidemic Cholera in Latin America: Spread and Routes of Transmission.” EPA, Environmental Protection Agency, https://pubmed.ncbi.nlm.nih.gov/8544225/

In this journal article, JP Guthmann discusses potential culprits for the spread of cholera in Latin America in the 1990’s. Guthmann highlights a link between the rates of cholera and the drinking water in certain Latin American cities. Guthmann documents the spread of cholera, noting the initial wave of the disease found on the coast of Peru, and how it quickly spread to other Latin American countries, specifically Ecuador and Colombia. Guthmann records that Peru had the greatest proportion of cholera cases and incidence rate out of all Latin American countries, noting that most cholera cases that were reported in 1991 were from Peru. Along with documenting the spread of the disease, Guthmann uncovers some routes of transmission, including contaminated drinking water, contaminated food and water from local food vendors, as well as contaminated crab meat transported in luggage. Although the source of the epidemic is still unknown, it’s most likely to have been the result of one of these factors. Guthmann concludes that the majority of Latin American countries lack sufficient water sanitation resources, and that these would be extremely helpful in preventing another cholera epidemic, as well as preventing the spread of other major waterborne illnesses. 

https://idsc.niid.go.jp/iasr/CD-ROM/records/14/image/I1580701.HTM

 Koo, Denise, et al. Epidemic Cholera in Latin America, 1991-1993: Implications of Case Definitions Used for Public Health Surveillance1. 1996, https://iris.paho.org/bitstream/handle/10665.2/27604/ev30n2p134.pdf?sequence=1&isAllowed=y. 

The authors of this report examine the total number of cases reported in various Latin American countries. The creators of the report sent a questionnaire regarding cholera case definitions to 20 Latin American countries that reported cases of cholera to the Pan American Health Organization (PAHO). The questionnaire was sent to all Latin American countries that reported cases of cholera, and asked how a reported case of cholera was defined (pg. 135). The goal of the report was to examine different definitions of cholera cases throughout Latin America, as well as determining regional trends of cholera cases. The report concluded that some countries only reported cases of cholera that were confirmed by a laboratory, whereas some countries reported cases based on epidemiologic criteria. Through the data collected from the questionnaire, the authors of this report determined that the Latin American countries that only report laboratory-confirmed cases are greatly underreporting cases, since some symptoms of cholera don’t require treatment used in laboratories(pg. 139). The authors of the report conclude by highlighting that cholera surveillance is necessary in order to prevent the spread of the disease, and that the only way cholera surveillance can be effective is if the cases are being reported accurately, which can be done by separating lab-confirmed cases and clinical cases. 

Tauxe R, Mintz E and Quick R. Epidemic Cholera in the New World: Translating Field Epidemiology into New Prevention Strategies. Emerging Infectious Diseases; 1:141-146https://hetv.org/resources/safewater/pub/pub/tauxe_r.htm

The authors of this report delve into the history of the cholera epidemic, highlighting  its origins off the coast of Peru, as well as offer multiple solutions for the issues present throughout Latin America that contributed to the rampant spread of the disease by explaining their investigation into the epidemic in cooperation with the PAHO and national public health authorities. As a result of their investigation, the authors of the report discovered multiple sources of contaminated water, with the main route of contamination  coming from poorly maintained municipal systems. Water coming from these municipal systems can be contaminated in several ways, including leaky pipes, lack of residual chlorine disinfectant, and frequent pressure drops. The authors provide several ways to solve these issues, including a unique method of adding citrus juice to water. Their research found that the acid in the juice was able to kill the cholera bacteria in the water. Other prevention methods noted by the authors include boiling the water and adding chlorine bleach. Uncooked seafood, such as fish and crab meat, was another major source of transmission, as many fishermen and food vendors sold their food products uncooked. The authors of the report, as well as the PAHO, urge citizens to heat/reheat and wash their food products thoroughly before eating, since many people avoided these measures and involuntarily spread cholera to other parts of Latin America. 

Secondary Sources Annotated Bibliography

Panisset, Ulysses B. “International Health Statecraft : The Case of Peru’s 1991 Cholera Epidemic.” Semantic Scholar, 1 Jan. 1996, https://www.semanticscholar.org/paper/International-health-statecraft-%3A-the-case-of-1991-Panisset/4c1f31a50a2e25f74b14a59097b259d25c720a3e. 

This report discusses the beginning of the cholera epidemic on Peru’s coast, and the devastating impact the epidemic had on the Peruvian economy in 1991. Panisset also offers new insight into Peru’s poor leadership during this time, and why this was a major catalyst for the rampant spread of the disease. Once it became public knowledge that cholera was discovered in Peru’s waters and would likely spread to nearby countries, many Latin American countries began to stop trading with Peru. Argentina, Bolivia, Chile, and Ecuador all began to boycott imports of food products from Peru, which caused around $28 million lost in Peruvian exports (pg. 22-23).  In addition to poor preexisting living conditions, Peru was failed by its health minister at the time, Dr. Carlos Vidal, who had to resign a few months into the epidemic after unsuccessfully regulating the fishing and agriculture industries during the initial wave of the disease (pg. 23). Panisset argues that the Latin American cholera epidemic of 1991 could have been prevented had Peru, as well as many other countries, implemented a health intelligence process, which would have included strategic planning, epidemiological surveillance, and information gathering. Panisset essentially states that if Peru had addressed its water quality earlier, as well as used more effective planning strategies beforehand, the epidemic would have been much more manageable to Peru’s citizens and economy. 

Lam, Connie, et al. “Evolution of Seventh Cholera Pandemic and Origin of 1991 Epidemic, Latin America.” Emerging Infectious Diseases, U.S. National Library of Medicine, July 2010, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321917/. 

The authors of this report begin by offering a potential cause of the cholera epidemic in 1990’s Latin America. The water contamination off the coast of Peru was likely the result of the discharge of contaminated ballast water from international trade ships coming into Peruvian ports. The report also finds that the epidemic in Latin America increased in parallel to the increase in cases in Africa, which the authors theorize that the epidemic in Latin America might have been brought over from Africa and are thus the same strain. Further microscopic analysis indicates that the strain affecting Africa likely underwent mutation and evolution before it impacted Latin America while still sharing some microscopic similarities. The authors of the report were able to definitively conclude after several tests that the cholera epidemic of Latin America was not brought over from Asia. With these results in mind, the authors of the report summarize that the Latin American cholera epidemic in 1991 was most likely the result of mass migration from Africa to Latin America. They also concluded that newly arisen genotypes, or groups, were able to easily spread cholera and other diseases because they were occuring at the same time in several countries. 

Quevedo F;Arámbulo P;Escalante JA;Estupiñán J;Almeida C;Cuellar J; “[Risk of Transmission of Cholera by Fish Products: Regional Perspective in South America].” Revue Scientifique Et Technique (International Office of Epizootics), U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/9580317/. 

The authors of this report offer additional insight as to how cholera was able to rapidly spread off of the coast of Peru. Economic and political conflicts, combined with the poor hygienic state of the affected countries, allowed cholera to easily be spread throughout Latin America and devastate communities. The authors of this report argue that contaminated fishery products were the main cause of the spread of cholera in Latin America, despite initially lacking evidence to support this argument. While the exact cause of contamination is unknown, the authors offer multiple possible explanations, all of them directly linking back to the poor water quality found in most Latin American countries. Many South American countries have a custom of marketing fishery products in ports and docks by “washing” them in sea water that is already polluted by phytoplankton and zooplankton, and it’s here where the cross-contamination can occur, as the disease can reach fruits and vegetables at the retail marketing level. As a result, the majority of fish products being sold throughout many Latin American areas were infected with cholera before being sold to customers. The authors also argue that these fish were not prepared correctly, which was another factor that contributed to the rampant spread of the disease. The authors conducted research and found that applying a temperature higher than 48° C can effectively eliminate the disease. 

Smith, Colleen. “The Political Ecology of Cholera in Peru.” University of Colorado at Boulder, 2012. uhttps://scholar.colorado.edu › downloads

In this report, Smith explains how the cholera epidemic was the product of structurally produced vulnerability, and how human and political ecology were important factors in shaping Peru before, during, and after the epidemic. Smith begins the report by stating that the poorer indigenous populations were hit the hardest by the epidemic, especially due to the fact that minimal health services could be provided to those areas (pg. 4). Poverty was a major factor for the spread of cholera in Peru, as the poorer citizens had less access to housing, clean water, and food, thus creating an ideal breeding ground for cholera to spread (pg. 11). Another alarming point Smith mentions in the report is the failure of the Peruvian government to act accordingly in response to the health crisis. The Ministry of Health was ill-equipped to handle a public health crisis of this nature, as they had limited supplies to treat those infected, as well as possible prevention methods (pg. 5). In an effort to downplay the threat of the disease, as well as escaping responsibility for the spread, the president of Peru at the time, Alberto Fujimori, ate raw seafood during a televised broadcast. This backfired however, as Fujimori soon contracted the disease, and the nation was sent into a panic (pg. 5).

Glossary

• Disinfection byproducts (DBP) 
  • unwanted compounds that are products of chemical reactions between chlorine and naturally occurring organic matter in source water

• Ballast
  • heavy material, such as gravel, sand, iron, or lead, placed low in a vessel to improve its stability

• Cross-contamination
  • the physical movement or transfer of harmful bacteria from one person, object or place to another