Recent Cholera Publications on PubMed

Microbiological survey and occurrence of bacterial foodborne pathogens in raw and ready-to-eat green leafy vegetables marketed in Tehran, Iran

August 8, 2021

Int J Hyg Environ Health. 2021 Aug 5;237:113824. doi: 10.1016/j.ijheh.2021.113824. Online ahead of print.


Fresh leafy (FL) and ready-to-eat (RTE) vegetables are recognized as an important source of foodborne disease outbreaks worldwide. Currently, there are no data available for the prevalnce of bacterial foodborne pathogens (FBPs) in raw vegetables consumed in Iran. Here, we evalated the presence of common bacterial FBPs among 366 samples of raw vegetables including 274 FL and 92 RTE collected from 21 districts of Tehran. The presence of FBPs were screened using conventional microbiological culture methods and real-time PCR assays. Overall, a higher rate of bacterial contamination was detected in FL compared to RTE samples using both detection methods. The results obtained by microbiological methods showed that Staphylococcus aureus (134/366, 36.6%), followed by Escherichia coli (85/366, 23.2%) and Clostridium perfringens (66/366, 18%) were detetcted as the most prevalent pathogens in this study. Vibrio cholerae was not detected in any of the samples either by microbiological methods or by the real-time PCR assays. There was a noticeable reduction in the proportion of Campylobacter positive samples using conventional microbiological methods (3.5%) compared to the real-time PCR assay (20.7%). The proportion of FL and RTE positive samples obtained by conventional microbiological methods was significantly different (P < 0.05) for C. perfringens, Campylobacter spp. and S. aureus. The proportion of positive samples in FL and RTE vegetables obtained by the real-time PCR assays was significantly different (P < 0.05) for C. perfringens, S. aureus, Helicobacter pylori and STEC/EHEC, the last one was found more frequently in RTE than in FL samples. Our findings indicated a contamination of FL and RTE vegetables in Iran with a range of well-known and emerging FBPs. Positivity and the distribution of bacterial species from the current data indicated different contamination sources, and overall a lack of effective decontamination steps during the production chain. Moreover, further information about the quality of the water, the hygiene measures implemented during the processing, storage and marketing are required to better identify the critical points and define the proper measures.

PMID:34365294 | DOI:10.1016/j.ijheh.2021.113824

A fructose/H(+) symporter controlled by a LacI-type regulator promotes survival of pandemic Vibrio cholerae in seawater

July 31, 2021

Nat Commun. 2021 Jul 30;12(1):4649. doi: 10.1038/s41467-021-24971-3.


The bacterium Vibrio cholerae can colonize the human intestine and cause cholera, but spends much of its life cycle in seawater. The pathogen must adapt to substantial environmental changes when moving between seawater and the human intestine, including different availability of carbon sources such as fructose. Here, we use in vitro experiments as well as mouse intestinal colonization assays to study the mechanisms used by pandemic V. cholerae to adapt to these environmental changes. We show that a LacI-type regulator (FruI) and a fructose/H+ symporter (FruT) are important for fructose uptake at low fructose concentrations, as those found in seawater. FruT is downregulated by FruI, which is upregulated when O2 concentrations are low (as in the intestine) by ArcAB, a two-component system known to respond to changes in oxygen levels. As a result, the bacteria predominantly use FruT for fructose uptake under seawater conditions (low fructose, high O2), and use a known fructose phosphotransferase system (PTS, Fpr) for fructose uptake under conditions found in the intestine. PTS activity leads to reduced levels of intracellular cAMP, which in turn upregulate virulence genes. Our results indicate that the FruT/FruI system may be important for survival of pandemic V. cholerae in seawater.

PMID:34330925 | DOI:10.1038/s41467-021-24971-3

Conflict and COVID-19 in Yemen: beyond the humanitarian crisis

July 23, 2021

Global Health. 2021 Jul 22;17(1):83. doi: 10.1186/s12992-021-00732-1.


BACKGROUND: Yemen has been left in shambles and almost destroyed by its devastating civil war, and is now having to deal with the spread of coronavirus. The Yemeni people have been are left to fend for themselves and faced many problems such as hunger, the ongoing war, infections, diseases and lack of equipment even before the COVID-19 pandemic. All together it is a humanitarian crisis. Only around 50% of the hospitals and healthcare facilities are in full working condition, and even those that are functioning are operating at nowhere near full potential. Healthcare staff and facilities lack necessary essential equipment and money.

CONCLUSION: As, sadly, is common in conflict-affected regions, the violence has brought with it a secondary disaster of infectious disease outbreaks. Yemen is not only battling COVID-19 amid a catastrophic war, but also has to deal with other diseases such as cholera, diphtheria and measles. A number of key measures are needed to support the current efforts against this deadly epidemic and its potential subsequent waves as well as to prevent further epidemics in Yemen.

PMID:34294097 | PMC:PMC8295627 | DOI:10.1186/s12992-021-00732-1

Rising cholera cases: Harnessing the momentum of COVID-19 to strengthen Nigeria's health systems

July 23, 2021

Int J Health Plann Manage. 2021 Jul 22. doi: 10.1002/hpm.3289. Online ahead of print.


Recently, there has been a surge in cholera cases in Nigeria. With the exhausting health resources and the overwhelming attention towards COVID-19, Nigeria is in danger of worsening the epidemiological profile of cholera in the country. Thus, it is pertinent to address the surge to prevent further weakening of the country's health system. In this paper, we, therefore, explore the various interrelated factors accounting for the surge in Nigeria. It is therefore suggested that multifaceted public health strategies be employed that leverage the current level of disease preparedness and response capacities to the COVID-19 pandemic to reduce the impacts of cholera. These measures will not only help in strengthening the country's health system but also enhance the achievement of the relevant strategies toward eradicating cholera.

PMID:34296467 | DOI:10.1002/hpm.3289

Non-cholera Vibrio species - currently still rare but growing danger of infection in the North Sea and the Baltic Sea

July 16, 2021

Internist (Berl). 2021 Jul 16. doi: 10.1007/s00108-021-01086-x. Online ahead of print.


BACKGROUND: The abundance of non-cholera Vibrio spp. in the aquatic environment shows a positive correlation with water temperatures. Therefore, climate change has an important impact on the epidemiology of human infections with these pathogens. In recent years large outbreaks have been repeatedly observed during the summer months in temperate climate zones.

OBJECTIVE: To inform medical professionals about the potentially life-threatening diseases caused by non-cholera Vibrio spp.

MATERIAL AND METHODS: Review of the current literature on infections with non-cholera Vibrio spp. in general and on the epidemiological situation in Germany in particular.

RESULTS: Non-cholera Vibrio spp. predominantly cause wound and ear infections after contact with contaminated seawater and gastroenteritis after consumption of undercooked seafood. As there have not been mandatory notification systems for these pathogens in Germany up to March 2020, a high number of unreported cases must be assumed. Immunosuppressed and chronically ill patients have a much higher risk for severe courses of diseases. If an infection with non-cholera Vibrio spp. is suspected anti-infective treatment should be promptly initiated and surgical cleansing is often necessary for wound and soft tissue infections.

CONCLUSION: Due to the ongoing global warming an increased incidence of human infections with non-cholera Vibrio spp. must be expected in the future. Medical professionals should be aware of these bacterial pathogens and the potentially life-threatening infections in order to enable timely diagnostics and treatment.

PMID:34269833 | DOI:10.1007/s00108-021-01086-x

Temperature and risk of infectious diarrhea: a systematic review and meta-analysis

July 16, 2021

Environ Sci Pollut Res Int. 2021 Jul 15. doi: 10.1007/s11356-021-15395-z. Online ahead of print.


Infectious diarrhea (ID) is an intestinal infectious disease including cholera, typhoid and paratyphoid fever, bacterial and amebic dysentery, and other infectious diarrhea. There are many studies that have explored the relationship between ambient temperature and the spread of infectious diarrhea, but the results are inconsistent. It is necessary to systematically evaluate the impact of temperature on the incidence of ID. This study was based on the PRISMA statement to report this systematic review. We conducted literature searches from CNKI, VIP databases, CBM, PubMed, Web of Science, Cochrane Library, and other databases. The number registered in PROSPERO is CRD42021225472. After searching a total of 4915 articles in the database and references, 27 studies were included. The number of people involved exceeded 7.07 million. The overall result demonstrated when the temperature rises, the risk of infectious diarrhea increases significantly (RRcumulative=1.42, 95%CI: 1.07-1.88, RRsingle-day=1.08, 95%CI: 1.03-1.14). Subgroup analysis found the effect of temperature on the bacillary dysentery group (RRcumulative=1.85, 95%CI: 1.48-2.30) and unclassified diarrhea groups (RRcumulative=1.18, 95%CI: 0.59-2.34). The result of the single-day effect subgroup analysis was similar to the result of the cumulative effect. And the sensitivity analysis proved that the results were robust. This systematic review and meta-analysis support that temperature will increase the risk of ID, which is helpful for ID prediction and early warning in the future.

PMID:34268683 | DOI:10.1007/s11356-021-15395-z

Precision of Serologic Testing from Dried Blood Spots Using a Multiplex Bead Assay

July 13, 2021

Am J Trop Med Hyg. 2021 Jul 12;105(3):822-827. doi: 10.4269/ajtmh.21-0140.


Multiplex bead assays (MBAs) for serologic testing have become more prevalent in public health surveys, but few studies have assessed their test performance. As part of a trachoma study conducted in a rural part of Ethiopia in 2016, dried blood spots (DBS) were collected from a random sample of 393 children aged 0 to 9 years, with at least two separate 6-mm DBS collected on a filter card. Samples eluted from DBS were processed using an MBA on the Luminex platform for antibodies against 13 antigens of nine infectious organisms: Chlamydia trachomatis, Vibrio cholera, enterotoxigenic Escherichia coli, Cryptosporidium parvum, Entamoeba histolytica, Camplyobacter jejuni, Salmonella typhimurium Group B, Salmonella enteritidis Group D, and Giardia lamblia. Two separate DBS from each child were processed. The first DBS was run a single time, with the MBA set to read 100 beads per well. The second DBS was run twice, first at 100 beads per well and then at 50 beads per well. Results were expressed as the median fluorescence intensity minus background (MFI-BG), and classified as seropositive or seronegative according to external standards. Agreement between the three runs was high, with intraclass correlation coefficients of > 0.85 for the two Salmonella antibody responses and > 0.95 for the other 11 antibody responses. Agreement was also high for the dichotomous seropositivity indicators, with Cohen's kappa statistics exceeding 0.87 for each antibody assay. These results suggest that serologic testing on the Luminex platform had strong test performance characteristics for analyzing antibodies using DBS.

PMID:34255738 | DOI:10.4269/ajtmh.21-0140

Global projections of temperature-attributable mortality due to enteric infections: a modelling study

July 10, 2021

Lancet Planet Health. 2021 Jul;5(7):e436-e445. doi: 10.1016/S2542-5196(21)00152-2.


BACKGROUND: Mortality due to enteric infections is projected to increase because of global warming; however, the different temperature sensitivities of major enteric pathogens have not yet been considered in projections on a global scale. We aimed to project global temperature-attributable enteric infection mortality under various future scenarios of sociodemographic development and climate change.

METHODS: In this modelling study, we generated global projections in two stages. First, we forecasted baseline mortality from ten enteropathogens (non-typhoidal salmonella, Shigella, Campylobacter, cholera, enteropathogenic Escherichia coli, enterotoxigenic E coli, typhoid, rotavirus, norovirus, and Cryptosporidium) under several future sociodemographic development and health investment scenarios (ie, pessimistic, intermediate, and optimistic). We then estimated the mortality change from baseline attributable to global warming using the product of projected annual temperature anomalies and pathogen-specific temperature sensitivities.

FINDINGS: We estimated that in the period 2080-95, the global mean number of temperature-attributable deaths due to enteric infections could be as low as 6599 (95% empirical CI 5441-7757) under the optimistic sociodemographic development and climate change scenario, or as high as 83 888 (67 760-100 015) under the pessimistic scenario. Most of the projected temperature-attributable deaths were from shigellosis, cryptosporidiosis, and typhoid fever in sub-Saharan Africa and South Asia. Considerable reductions in the number of attributable deaths were from viral infections, such as rotaviral and noroviral enteritis, which resulted in net reductions in attributable enteric infection mortality under optimistic scenarios for Latin America and the Caribbean and East Asia and the Pacific.

INTERPRETATION: Temperature-attributable mortality could increase under warmer climate and unfavourable sociodemographic conditions. Mitigation policies for limiting global warming and sociodemographic development policies for low-income and middle-income countries might help reduce mortality from enteric infections in the future.

FUNDING: Japan Society for the Promotion of Science, Japan Science and Technology Agency, and Spanish Ministry of Economy, Industry, and Competitiveness.

PMID:34245714 | DOI:10.1016/S2542-5196(21)00152-2

Distribution of virulence factors and its relatedness towards the antimicrobial response of enterotoxigenic Escherichia coli (ETEC) strains isolated from patients in Kolkata, India

July 9, 2021

J Appl Microbiol. 2021 Jul 9. doi: 10.1111/jam.15206. Online ahead of print.


AIM: Enterotoxigenic Escherichia coli (ETEC) is one of the most widely recognized diarrheal pathogens in developing countries. Advancement of ETEC vaccine development depends on the antigenic determinants of the ETEC isolates from a particular geographical region. So, the aim here was to comprehend the distribution of virulence determinants of the clinical ETEC strains of this region. Additionally, attempt was made to find any correlation with the antimicrobial response pattern.

METHODS AND RESULTS: Multiplex PCR was employed to identify virulence determinants followed by confirmatory singleplex PCR. For observation of antibiotic response, the Kirby-Bauer method was used. Out of 379 strains, 46% strains harboured both the enterotoxins ST and LT, whereas 15% were LT only. Among the major colonization factors, CS6 (41%) was the most prevalent followed by CFA/I (35%) and CFA/III was the lowest (3%). Among the minor colonization factors, CS21 (25%) was most prevalent, while CS15 showed the lowest (3%) presence. Among the non-classical virulence factors, EatA (69%) was predominant. ETEC strains harbouring CS6 showed resistance towards commonly used drug Ciprofloxacin (70%).

CONCLUSION: CS6 and elt+est toxin genes co-occurred covering 51% of the isolates. CS21 was found in most strains with est genes (43%). EatA was found to occur frequently when ST was present alone or with LT. CS6-harboring strains showed an independent correlation to antimicrobial resistance.

SIGNIFICANCE AND IMPACT OF STUDY: This study would aid in identifying the commonly circulating ETEC isolates of Kolkata, India, and their prevalent virulence determinants. Knowledge of antibiotic resistance pattern would also help in the appropriate use of antibiotics. Further, the study would aid in identifying the multivalent antigens suitable for region-specific ETEC vaccine with maximum coverage.

PMID:34242448 | DOI:10.1111/jam.15206