Emergence Of Cholera Research Articles

Factors associated with the cholera outbreak in Al-Mahweet-Yemen: Analytic Study.

The emergence of cholera in 2016 in Yemen, worsened the morbidity and mortality of diarrheal diseases, particularly among children under five. Multiple outbreaks in Yemen are triggered by years of conflict and the collapse of basic infrastructure including water supply and sanitation systems. This study aims to assess factors associated with the cholera outbreak, in a cholera-prone region, in Al-Mahweet, Yemen. We conducted a multivariate analysis of the data collected through a household survey of 384 households in Al-Mahweet, Yemen. Families with children under five years, large households, and those living in Al Mahweet district were associated with a higher incidence of cholera. Water treatment by boiling, filtering, and chlorination as a protective practice against cholera showed a borderline significance, while other WASH practices including regular hand washing, open defection, safe water source, and improved sanitation facilities were statistically insignificant. Community awareness of cholera transmission and prevention measures showed no association with cholera incidence. Findings suggest that living conditions, including large households and lack of access to treated water, increase the risk of cholera. Interventions to increase access to treated water and improve the hygienic conditions of large households are of central importance. Affected communities must receive effective educational campaigns that are adjusted to change hygienic practices and improve knowledge of cholera transmission and protection measures.

Rising cases of cholera in Ethiopia: a need for sustainable wash practices?

Rising cases of cholera in Ethiopia: a need for sustainable wash practices?

New Insights into Vibrio cholerae Biofilms from Molecular Biophysics to Microbial Ecology.

With the discovery that 48% of cholera infections in rural Bangladesh villages could be prevented by simple filtration of unpurified waters and the detection of Vibrio cholerae aggregates in stools from cholera patients it was realized V. cholerae biofilms had a central function in cholera pathogenesis. We are currently in the seventh cholera pandemic, caused by O1 serotypes of the El Tor biotypes strains, which initiated in 1961. It is estimated that V. cholerae annually causes millions of infections and over 100,000 deaths. Given the continued emergence of cholera in areas that lack access to clean water, such as Haiti after the 2010 earthquake or the ongoing Yemen civil war, increasing our understanding of cholera disease remains a worldwide public health priority. The surveillance and treatment of cholera is also affected as the world is impacted by the COVID-19 pandemic, raising significant concerns in Africa. In addition to the importance of biofilm formation in its life cycle, V. cholerae has become a key model system for understanding bacterial signal transduction networks that regulate biofilm formation and discovering fundamental principles about bacterial surface attachment and biofilm maturation. This chapter will highlight recent insights into V. cholerae biofilms including their structure, ecological role in environmental survival and infection, regulatory systems that control them, and biomechanical insights into the nature of V. cholerae biofilms.

A Re-Look at Cholera Pandemics from Early Times to Now in the Current Era of Epidemiology

Cholera affects about three million people annually and kills several thousands. Since 1817 seven cholera pandemics have been described. While the nature of the strains responsible for the first four pandemics are not known, the fifth and sixth pandemics are associated with Vibrio cholerae O1 classical biotype. In the 1960s, V. cholerae El Tor replaced classical strains worldwide, ushering in the seventh pandemic. El Tor cholera is typified with less severe diarrhea, a lower case fatality rate and a higher percentage of asymptomatic cases. Historically, the Indian subcontinent was thought to be the homeland where cholera originated and has been implicated in spreading of the disease. Cholera broke out in Africa and now seems to be continuous and recurrent, leading to high morbidity and mortality in some countries. Current conflicts in the Middle East have been associated with the breakdown of healthcare systems and the emergence of cholera there in a big way. Several discoveries in the past two centuries helped us to understand and manage the disease. Some of the greatest inventions such as rehydration therapy have saved the lives of countless people afflicted with cholera. Whole genome sequencing of V. cholerae and the modern molecular epidemiology of cholera have led to advancements in understanding of the disease and also how the organism has persisted and re-emerged in new areas during the seventh pandemic. Currently, water, sanitation, and hygiene along with the new generation oral cholera vaccines are considered as important interventions and beneficial public health tools in cholera endemic countries and in areas at risk for outbreaks. This review highlights the pandemics that lead to important discoveries and also the new molecular approach in understanding the epidemiology of cholera.

Endemic Cholera in India and Imported Cholera in Russia: What is Common?

The endemicity of cholera in India has been well researched. Among the other endemic areas, Indian subcontinent appears to be the cradle of Vibrio cholerae genovariants, which subsequently spread worldwide. In contrast, all the cholera cases recorded in Russia are of imported origin. In the past century, such importations might result in epidemics, which, however, ended with elimination of toxigenic V. cholerae (TVC) from the affected areas. Currently, the incidence of TVC in water reservoirs or infected returnees from Asian countries are rare events, mostly due to constant surveillance activities. Furthermore, the climatic conditions in the majority of Russian regions are unfavorable for longterm environmental survival of the pathogen. On the other hand, global shifts in climate accompanied by unexpected anomalies in previously stable climatic zones may promote dissemination of imported TVC and emergence of cholera. In some regions of Russia, seasonal weather patterns are pretty similar to Indian. Molecular studies of isolates from diverse territories show that TVC have been introduced into new areas and acquired additional traits, absent in their ancestors.This article describes genomic characteristics of TVC isolates from Russia, India and some other countries. The review is complemented by bioinformatics analysis of important genetic markers to discriminate between clones that emerged in endemic regions and were imported into cholera-free locations. We have found more evidence in support of primary Indian origin of recent genovariants and their ongoing transformation, including the emergence of a new rtxA gene allele with a 60 bp deletion in addition to the previously known null mutation. In certain conditions, TVC could pose a potential threat of spreading epidemic cholera into Russia and other territories. Cholera control requires joint efforts of researchers to learn more about the pathogen at the molecular level for developing effective strategies to protect the humankind throughout the world.

Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador.

Cholera emergence is strongly linked to local environmental and ecological context. The 1991–2004 pandemic emerged in Perú and spread north into Ecuador’s El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae, by polymerase chain reaction (PCR). We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera–estuarine system to anticipate potential future cholera outbreaks.

El Niño, Climate, and Cholera Associations in Piura, Peru, 1991–2001: A Wavelet Analysis

In Peru, it was hypothesized that epidemic cholera in 1991 was linked to El Niño, the warm phase of El Niño-Southern Oscillation. While previous studies demonstrated an association in 1997-1998, using cross-sectional data, they did not assess the consistency of this relationship across the decade. Thus, how strong or variable an El Niño-cholera relationship was in Peru or whether El Niño triggered epidemic cholera early in the decade remains unknown. In this study, wavelet and mediation analyses were used to characterize temporal patterns among El Niño, local climate variables (rainfall, river discharge, and air temperature), and cholera incidence in Piura, Peru from 1991 to 2001 and to estimate the mediating effects of local climate on El Niño-cholera relationships. The study hypothesis is that El Niño-related connections with cholera in Piura were transient and interconnected via local climate pathways. Overall, our findings provide evidence that a strong El Niño-cholera link, mediated by local hydrology, existed in the latter part of the 1990s but found no evidence of an El Niño association in the earlier part of the decade, suggesting that El Niño may not have precipitated cholera emergence in Piura. Further examinations of cholera epicenters in Peru are recommended to support these results in Piura. For public health planning, the results may improve existing efforts that utilize El Niño monitoring for preparedness during future climate-related extremes in the region.

Avian Cholera emergence in Arctic-nesting northern Common Eiders: using community-based, participatory surveillance to delineate disease outbreak patterns and predict transmission risk

Emerging infectious diseases are a growing concern in wildlife conservation. Documenting outbreak patterns and determining the ecological drivers of transmission risk are fundamental to predicting disease spread and assessing potential impacts on population viability. However, evaluating disease in wildlife populations requires expansive surveillance networks that often do not exist in remote and developing areas. Here, we describe the results of a community-based research initiative conducted in collaboration with indigenous harvesters, the Inuit, in response to a new series of Avian Cholera outbreaks affecting Common Eiders (Somateria mollissima) and other comingling species in the Canadian Arctic. Avian Cholera is a virulent disease of birds caused by the bacterium Pasteurella multocida. Common Eiders are a valuable subsistence resource for Inuit, who hunt the birds for meat and visit breeding colonies during the summer to collect eggs and feather down for use in clothing and blankets. We compiled the observations of harvesters about the growing epidemic and with their assistance undertook field investigation of 131 colonies distributed over >1200 km of coastline in the affected region. Thirteen locations were identified where Avian Cholera outbreaks have occurred since 2004. Mortality rates ranged from 1% to 43% of the local breeding population at these locations. Using a species-habitat model (Maxent), we determined that the distribution of outbreak events has not been random within the study area and that colony size, vegetation cover, and a measure of host crowding in shared wetlands were significantly correlated to outbreak risk. In addition, outbreak locations have been spatially structured with respect to hypothesized introduction foci and clustered along the migration corridor linking Arctic breeding areas with wintering areas in Atlantic Canada. At present, Avian Cholera remains a localized threat to Common Eider populations in the Arctic; however expanded, community-based surveillance will be required to track disease spread.

Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates.

BackgroundSince cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hotspots including the African Great Lakes Region and West Africa.Methodology/Principal FindingsIn this study, we applied MLVA (Multi-Locus Variable Number Tandem Repeat Analysis) typing of 337 Vibrio cholerae isolates from recent cholera epidemics in the Democratic Republic of the Congo (DRC), Zambia, Guinea and Togo. We aimed to assess the relationship between outbreaks. Applying this method, we identified 89 unique MLVA haplotypes across our isolate collection. MLVA typing revealed the short-term divergence and microevolution of these Vibrio cholerae populations to provide insight into the dynamics of cholera outbreaks in each country. Our analyses also revealed strong geographical clustering. Isolates from the African Great Lakes Region (DRC and Zambia) formed a closely related group, while West African isolates (Togo and Guinea) constituted a separate cluster. At a country-level scale our analyses revealed several distinct MLVA groups, most notably DRC 2011/2012, DRC 2009, Zambia 2012 and Guinea 2012. We also found that certain MLVA types collected in the DRC persisted in the country for several years, occasionally giving rise to expansive epidemics. Finally, we found that the six environmental isolates in our panel were unrelated to the epidemic isolates.Conclusions/SignificanceTo effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.

Earthquake in Haiti creates cholera epidemic disease and potential economic disaster: Why it is not curable?

Background: An unwelcome guest after the devastating 2010 earthquake in Haiti was the shocking emergence of cholera. Four months after the earthquake, 215936 cases had been reported and of these 4131 patients had been infected and died. Mathematical models have been developed to predict the spread of cholera across the entire country and to explore the effects of disease-control interventions. Methods & Materials: Objective: to predict the timing and spread of regional cholera epidemics in Haiti using a mathematical model and to examine the efficacy of disease-controlled interventions. Design: A mathematical model was employed showing person-to-person within and between the 10 geographic regions of the country. Data was obtained from Haitian hospitalization sources plus the 2009 census data. The model involves both waterborne and person-to-person transmission of cholera in order to predict its spread across the country. The model also attempts to assess the effects of 2 distinct interventions, namely vacination on a limited scale and the provision of clean water. Results: The model predicted a rate of transmission between 2.06 to 2.78 and this closely matched empirical observations. The model also suggested an intervention would reduce the risk of cholera spreading by 3%, and this was estimated to be twice the reduction that would result from simply implementing clean water to the same number of individuals. Although the model purports to project the spread of cholera and offer an intervention, it also acknowledges cholera continuing to take a toll on the population for the near future. Conclusion: Despite limited surveillance data, the model comes close to reported disease patterns. The model is a tool that planners can use to manage the epidemic, gain insights into the behavior of this infectious disease, and provide a useful tool for decision making. The possibility of eradicating cholera is yet to be determined. Should cholera become epidemic in Haiti, it will represent a threat to other countries in the region.

Guidance for effective elimination of cholera epidemics in a sustainable manner in the Democratic Republic of Congo and other high risk countries

In a re-emerging context of cholera worldwide, especially in Africa, a replicable approach has been developed by governmental, non-governmental and international organisations in the Democratic Republic of Congo, with the support of the Veolia Environnement Foundation. The developed methodology integrates epidemiology studies with water, sanitation and hygiene studies. It consists in effectively eliminating cholera and other waterborne diseases by securing and reinforcing access to potable water, effective sanitation services and hygiene education. A Geographical Information System is used to combine the results of epidemiology studies with water, sanitation and hygiene diagnosis, to establish a scientifically-based cholera hotspots mapping, and identify at risk populations in each of the hotspots. In the D.R.C., the epidemiology studies led to the identification of 8 “hotspots” of cholera emergence in the Eastern part of the country, in the Great Lakes Region, in which preventive actions are being focused. On the long run, preventive interventions are expected to significantly decrease cholera and other waterborne diseases incidence, by increasing access to safe water and reducing unsafe water use for instance. Indeed, more reliable and close water access will encourage better hygiene practices in the households, and will help saving time for women and children generally involved in the water collection. The impact is consequently expected to be broad: sanitary, social and economic. The approach goes far beyond the traditional emergency medical response to cholera epidemics. It is being implemented in the D.R.C. to change the traditional cholera response paradigm from treatment to prevention. Based on the case study being held in the D.R.C., the Global Alliance Against Cholera (G.A.A.C. – www.choleraalliance.org) was created in 2010, bringing together international private and public stakeholders, recognised as experts in the fields of Cholera, Health, Water, Sanitation and Hygiene. The main objective of the Alliance is to advocate for the sustainable multisectoral approach adopted in the D.R.C., at an international level and that can serve as a model for other areas and communities affected by the disease. The G.A.A.C. also works on strategies to better integrate the common approach into affected countries’ national policies, in order to sustainably eliminate this scourge.

Isolation of Vibrio cholera El Tor Inaba From Lemna minor and Eichhornia crassipens Roots in Veracruz, Mexico.

Background:During epidemic periods, the strain Vibrio cholera El Tor has been isolated from the aquatic macrophyte roots of Eichhornia crassipens and Lemna minor, suggesting that aquatic plants could be environmental reservoirs through either a non-specific association or a commensalism relationship. Therefore, it is important to understand V. cholera reservoirs in order to establish prevention strategies against this pathogen.Objectives:Our interest was to determine whether V. cholera could be isolated and typified from L. minor and E. crassipens roots.Materials and Methods:From 2004 to 2005, plants were collected from various ecological niches and the roots were used to isolate V. cholera. Standard bacteriological, biochemical and serological tests were used for its typification.Results:In five out of the nine ecological niches explored, we collected either L. minor or E. crassipens, as these specimens cohabited only in two niches. V. cholera was isolated from both L. minor and E. crassipens roots. The isolated V. cholera showed the same biochemical characteristics as the pure V. cholera strain which was used as a control. The isolated V. cholera corresponded to V. cholera O1 El Tor Inaba, which is the same serotype related to the last outbreak in Mexico.Conclusions:For first time V. cholera El Tor Inaba has been isolated several years after the last emergence of cholera in Mexico. A viable and cultivable V. cholera strain, sourced from freshwater niches in E. crassipens and L. minor roots, suggests the importance of these plants as a permanent aquatic reservoir for these organisms. The monitoring of E. crassipens and L. minor is the responsibility of health institutions in order to evaluate the ongoing risks.

Matter Pictured In Its Place: Cholera and the Slums of London

During the nineteenth century, issues surrounding ‘foreign’ contamination were raised by the emergence of cholera in India, and by its rapid spread and frequent outbreaks in England. Between 1831 and 1866 Britain experienced four epidemics of the disease. While much of the discourse on cholera was textual, images were marshalled to support and visualize the arguments made about the disease and the conditions in which it bred. Cholera appeared to thrive in the fetid environments of the urban poor; therefore, the slums of London were represented as cholera’s home, while their inhabitants were characterized as immoral and unhealthy. Parts of the city were identified as possessing the same conditions as India and the Black Hole of Calcutta. Significantly, while the conflation of cholera with the slums, India, and the threat of degradation was explicitly stated in texts on the disease, the images that accompanied these texts did not directly depict the illness. Although cholera itself was not represented, the pictures moved beyond the texts by powerfully evoking visual tropes of Indian barbarism to confront and unsettle viewers with the dangers the malady posed to the heart of the British Empire.

Reexamining El Niño and Cholera in Peru: A Climate Affairs Approach

Abstract In the 1990s Peru experienced the first cholera epidemic after almost a century. The source of emergence was initially attributed to a cargo ship, but later there was evidence of an El Niño association. It was hypothesized that marine ecosystem changes associated with El Niño led to the propagation of V. cholerae along the coast of Peru, which in turn initiated the onset of the epidemic in 1991. Earlier studies supported this explanation by demonstrating a relationship between elevated temperatures and increased cholera incidence in Peru; however, other aspects of El Niño–Southern Oscillation (ENSO) and their potential impacts on cholera were not investigated. Therefore, this study examines the relationship between El Niño and cholera in Peru from a holistic view of the ENSO cycle. A “climate affairs” approach is employed as a conceptual framework to incorporate ENSO’s multidimensional nature and to generate new hypotheses about the ENSO and cholera association in Peru. The findings reveal that ENSO may have been linked to the cholera epidemic through multiple pathways, including rainfall extremes, La Niña, and social vulnerability, with impacts depending on the geography of teleconnections within Peru. When the definition of an ENSO event is examined, cholera appears to have emerged either during ENSO neutral or La Niña conditions. Furthermore, the analysis herein suggests that the impact of El Niño arrived much later, possibly resulting in heightened transmission in the austral summer of 1992. In conclusion, a modified hypothesis with these new insights on cholera emergence and transmission in Peru is presented.

Bones of Contention: Corpse Traffic and Ottoman-Iranian Rivalry in Nineteenth-Century Iraq

This article examines Ottoman responses to Iranians bringing corpses for burial in holy Shi`i sites in Ottoman Iraq, and focuses on questions of sovereignty, frontiers, commerce, and sanitation. Bringing together the Shi`is of both sides of the Ottoman-Iranian frontier, this curious border crossing constituted a major point of contention between the Ottoman Empire and Safavid and Qajar Iran. One of the most persistent religio-economic activities of Middle Eastern history, corpse traffic continued almost unabated until the emergence of cholera as a global health threat. The emergence of cholera and discussions around corpse traffic and pilgrimage to the `atabat helped transform one of the longest running unresolved issues of the Islamic world: namely, the undefined border between the Ottoman Empire and Iran.

Don't Drink the Water

Zimbabwe's 2008-09 cholera outbreak holds the dubious distinction of being Africa's worst on record. At the end of May 2009, the World Health Organization reported 98,424 cases of the disease and 4276 deaths. Other sources estimate that the number of cases has topped 100,000 since September 2008. ' The near-collapse of the country's water and sanitation infrastructure has dramatically reduced Zimbabweans' access to clean water and proper sewage treatment systems. With a case fatality rate of over four percent, Zimbabwe's cholera outbreak has exacerbated problems in a country already weakened by economic collapse and political mismanagement.Cholera outbreaks are relatively rare in the absence of war, so why did it happened in Zimbabwe in 2008 and 2009? We cannot understand the answer to that question without examining government policies and actions in the years prior to the outbreak. The cholera outbreak in Zimbabwe is both a humanitarian crisis and symptomatic of political decisions made by the Zimbabwean government. Cholera did not emerge out of nowhere in Zimbabwe; it emerged because government policies allowed it to emerge. Epidemics do not just happen. They are not random events. They have histories, write Barnett and Whiteside.2 We can identify direct relationships between the policies and decisions of President Robert Mugabe and his ZANU-PF (Zimbabwe African National Union- Patriotic Front) party and cholera's emergence. The takeover of municipal water supplies by the national government to weaken the opposition Movement for Democratic Change (MDC) and the government's economic mismanagement have worked in tandem to allow cholera to flourish.Understanding the underlying dynamics that gave rise to the cholera outbreak in the first place, though, does not necessarily tell us how we should respond to this humanitarian crisis. If the cholera outbreak in Zimbabwe occurred because the government did not effectively provide public goods to its citizenry, how can the social contract be reestablished? Does the international community have a role to play? If so, should it work through official state channels?This article has two goals. First, it seeks to demonstrate how infectious disease outbreaks like cholera in Zimbabwe are political crises as much as epidemiological ones. Specific government policies give rise to the conditions under which a disease like cholera can flourish. Second, it aims to outline potential remedies to prevent future cholera outbreaks. The international community can potentially play a role in preventing future cholera outbreaks in Zimbabwe, but the bulk ofthe burden lies with Zimbabwe. This speaks to larger questions about the role ofthe international community in protecting and promoting health worldwide. Health has traditionally been the province of national governments, but the international community has taken a greater interest in health and infectious disease in recent years. This has led to questions about the appropriate balance between the two, and the case of cholera in Zimbabwe offers us an opportunity to explore that balance.CHOLERA OUTBREAK IN ZIMBABWECholera spreads via a bacterium, Vibrio cholerae, where water supplies, sanitation, food safety, and hygiene practices are inadequate and poor sanitation and unsafe drinking water supplies predominate.3 Symptoms frequently occur within two to three days of exposure. These include a bloated feeling in the abdomen, generally with no accompanying fever, that quickly gives way to very watery stool. Cholera can cause severe dehydration and kidney failure, leading to death in as few as 18 hours. Without treatment, mortality rates can range from 50 to 90 percent, making it one of the most historically feared of diseases. However, treatment with oral rehydration therapies is remarkably effective if administered in a timely fashion, bringing the case fatality rate below one percent.Cholera also has a history of creating political divisions within societies. …

Vibrio cholerae in the environment.

The emergence of cholera has been a significant public health problem around the world and battle to completely control this deadly disease continues. Prevalence of Vibrio cholerae (V. cholerae) microorganisms in the environment was considered as the most important factor in this regard. Soil, fresh water, sea water, aquatic plants, animals and some birds have been made target for search if they were providing reserve shelter to the causative agent during inter epidemic periods. Multiple environmental factors have been considered to have the aetiological relationship as no single source is found to host the microorganisms in an inter-epidemic period. We have attempted to review the literature from different parts of the world; encompassing experimental and isolation studies of pathogenic and non-pathogenic strains of V. cholerae in the environment. The non-pathogenic strains were also included due to converting behavior of the agents in the changing environmental scenario to pathogenic forms.

New insights on the emergence of cholera in Latin America during 1991: the Peruvian experience.

After a century of absence, in late January 1991, Vibrio cholerae invaded the Western Hemisphere by way of Peru. Although a number of theories have been proposed, it is still not understood how that invasion took place. We reviewed the clinical records of persons attending hospital emergency departments in the major coastal cities of Peru from September through January of 1989/1990 and 1990/1991. We identified seven adults suffering from severe, watery diarrhea compatible with a clinical diagnosis of cholera during the four months preceding the cholera outbreak, but none during the previous year. The patients were scattered among five coastal cities along a 1,000 km coastline. We postulate that cholera vibrios, autochthonous to the aquatic environment, were present in multiple coastal locations, and resulted from environmental conditions that existed during an El Nino phenomenon. Once introduced into the coastal communities in concentrations large enough for human infection to occur, cholera spread by the well-known means of contaminated water and food.

Emergence of cholera in the Central African Republic.

Emergence of cholera in the Central African Republic.

Molecular evolution of Vibrio cholerae O1 strains isolated in Lima, Peru, from 1991 to 1995.

Following the emergence of cholera in Lima, Peru, in 1991, isolates of Vibrio cholerae O1 biotype El Tor recovered from patients in various parts of Lima were selected and characterized. Ribotyping and pulsed-field gel electrophoresis (PFGE) revealed four BglI ribotypes and eight NotI PFGE types among 50 V. cholerae O1 strains recovered from patients with cholera in Lima from 1991 to 1995, with certain genotypes appearing to cluster geographically. While differences in ribotype and PFGE type patterns suggest that genetic changes are occurring in the strain responsible for the Latin American cholera epidemic, more frequently than previously reported, 40 (80%) O1 strains showed an identical ribotype pattern and 41 (82%) strains showed closely related PFGE types, types 1, 2, or 3, that differed by less than three restriction fragments. All strains were susceptible to nine antibacterial agents studied. In 1991, more than 95% of the clinical V. cholerae O1 strains were serotype Inaba, whereas from 1992, serotype Ogawa began to predominate, with more than 90% of the isolates being of the Ogawa serotype in 1995. The small differences in genotypes of V. cholerae O1 is remarkable because cholera is highly seasonal in coastal areas of Peru and support the hypothesis that the epidemic strain reemerges from an environmental source. However, the relative high rate of genetic changes within V. cholerae O1 as shown by ribotyping and PFGE should be taken into consideration when typing patterns of V. cholerae O1 associated with cholera in Latin America are evaluated.