Recent Cholera Publications on PubMed

Characterization of non-typhoidal Salmonella isolates from children with acute gastroenteritis, Kolkata, India, during 2000-2016.

January 29, 2021
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Characterization of non-typhoidal Salmonella isolates from children with acute gastroenteritis, Kolkata, India, during 2000-2016.

Braz J Microbiol. 2020 Jun;51(2):613-627

Authors: Jain P, Chowdhury G, Samajpati S, Basak S, Ganai A, Samanta S, Okamoto K, Mukhopadhyay AK, Dutta S

Abstract
Non-typhoidal Salmonella (NTS) is an important cause of acute gastroenteritis in children. The study was undertaken to determine the isolation rate, serovar prevalence, antimicrobial resistance (AMR) profiles, and molecular subtypes of NTS from a hospital-based diarrheal disease surveillance in Kolkata, India. Rectal swabs were collected from children (< 5 years of age) with acute gastroenteritis from 2000 to 2016. Samples were processed following standard procedures for identification of NTS. The isolates were tested for antimicrobial susceptibility, AMR genes, plasmid profiles, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE) subtypes. A total of 99 (1.0%) Salmonella isolates were recovered from 9957 samples processed. Of the 17 Salmonella serovars identified, S. Worthington (33%) was predominant followed by S. Enteritidis (13%), S. Typhimurium (12%), and others. The isolates showed high resistance towards nalidixic acid (43%), ampicillin (34%), third-generation cephalosporins (32%), and azithromycin (25%), while low resistance was observed for fluoroquinolones (2%). Extended-spectrum beta-lactamase production (blaCTX-M-15 and blaSHV-12 genes) and azithromycin resistance (mphA gene) were common in S. Worthington, while fluoroquinolone resistance (gyrA and parC mutations) was found in S. Kentucky. Diverse plasmid profiles were observed among the isolates. PFGE analysis identified genetically related strains of each serovar in circulation. MLST also revealed phylogenetically clonal isolates of which S. Worthington ST592 and ciprofloxacin-resistant S. Kentucky ST198 were not reported earlier from India. NTS resistant to current drugs of choice poses a potential public health problem. Continuous monitoring of AMR profiles and molecular subtypes of NTS serovars is recommended for controlling the spread of resistant organisms.

PMID: 31898246 [PubMed - indexed for MEDLINE]

Sensor-based localization of epidemic sources on human mobility networks.

January 28, 2021
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Sensor-based localization of epidemic sources on human mobility networks.

PLoS Comput Biol. 2021 Jan 27;17(1):e1008545

Authors: Li J, Manitz J, Bertuzzo E, Kolaczyk ED

Abstract
We investigate the source detection problem in epidemiology, which is one of the most important issues for control of epidemics. Mathematically, we reformulate the problem as one of identifying the relevant component in a multivariate Gaussian mixture model. Focusing on the study of cholera and diseases with similar modes of transmission, we calibrate the parameters of our mixture model using human mobility networks within a stochastic, spatially explicit epidemiological model for waterborne disease. Furthermore, we adopt a Bayesian perspective, so that prior information on source location can be incorporated (e.g., reflecting the impact of local conditions). Posterior-based inference is performed, which permits estimates in the form of either individual locations or regions. Importantly, our estimator only requires first-arrival times of the epidemic by putative observers, typically located only at a small proportion of nodes. The proposed method is demonstrated within the context of the 2000-2002 cholera outbreak in the KwaZulu-Natal province of South Africa.

PMID: 33503024 [PubMed - as supplied by publisher]

The Novel Coronavirus Enigma: Phylogeny and Analyses of Coevolving Mutations Among the SARS-CoV-2 Viruses Circulating in India.

January 27, 2021
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The Novel Coronavirus Enigma: Phylogeny and Analyses of Coevolving Mutations Among the SARS-CoV-2 Viruses Circulating in India.

JMIR Bioinform Biotech. 2020;1(1):e20735

Authors: Banerjee A, Sarkar R, Mitra S, Lo M, Dutta S, Chawla-Sarkar M

Abstract
Background: The RNA genome of the emerging novel coronavirus is rapidly mutating, and its human-to-human transmission rate is increasing. Hence, temporal dissection of their evolutionary dynamics, the nature of variations among different strains, and understanding the single nucleotide polymorphisms in the endemic settings are crucial. Delineating the heterogeneous genomic constellations of this novel virus will help us understand its complex behavior in a particular geographical region.
Objective: This is a comprehensive analysis of 95 Indian SARS-CoV-2 genome sequences available from the Global Initiative on Sharing All Influenza Data (GISAID) repository during the first 6 months of 2020 (January through June). Evolutionary dynamics, gene-specific phylogeny, and the emergence of the novel coevolving mutations in 9 structural and nonstructural genes among circulating SARS-CoV-2 strains across 12 different Indian states were analyzed.
Methods: A total of 95 SARS-CoV-2 nucleotide sequences submitted from India were downloaded from the GISAID database. Molecular Evolutionary Genetics Analysis, version X software was used to construct the 9 phylogenetic dendrograms based on nucleotide sequences of the SARS-CoV-2 genes. Analyses of the coevolving mutations were done in comparison to the prototype SARS-CoV-2 from Wuhan, China. The secondary structure of the RNA-dependent RNA polymerase/nonstructural protein NSP12 was predicted with respect to the novel A97V mutation.
Results: Phylogenetic analyses revealed the evolution of "genome-type clusters" and adaptive selection of "L"-type SARS-CoV-2 strains with genetic closeness to the bat severe acute respiratory syndrome-like coronaviruses. These strains were distant to pangolin or Middle East respiratory syndrome-related coronavirus strains. With regard to the novel coevolving mutations, 2 groups have been seen circulating in India at present, the "major group" (66/95, 69.4%) and the "minor group" (21/95, 22.1%) , harboring 4 and 5 coexisting mutations, respectively. The "major group" mutations fall in the A2a clade. All the minor group mutations, except 11083G>T (L37F, NSP6 gene), were unique to the Indian isolates.
Conclusions: This study highlights the rapidly evolving SARS-CoV-2 virus and the cocirculation of multiple clades and subclades. This comprehensive study is a potential resource for monitoring the novel mutations in the viral genome, interpreting changes in viral pathogenesis, and designing vaccines or other therapeutics.

PMID: 33496683 [PubMed - as supplied by publisher]

Hepatitis-B virus infection in India: Findings from a nationally representative serosurvey, 2017-18.

January 27, 2021
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Hepatitis-B virus infection in India: Findings from a nationally representative serosurvey, 2017-18.

Int J Infect Dis. 2020 Nov;100:455-460

Authors: Murhekar MV, Santhosh Kumar M, Kamaraj P, Khan SA, Allam RR, Barde P, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D, Tandale BV, Topno RK, Girish Kumar CP, Sabarinathan R, Bitragunta S, Grover GS, Lakshmi PVM, Mishra CM, Sadhukhan P, Sahoo PK, Singh SK, Yadav CP, Kumar R, Dutta S, Toteja GS, Gupta N, Mehendale SM, ICMR – Serosurvey group

Abstract
INTRODUCTION: India introduced a hepatitis-B (HB) vaccine in the Universal Immunization Program in 2002-2003 on a pilot basis, expanded to ten states in 2007-2008 (phase-1), and the entire country in 2011-2012 (phase-2). We tested sera from a nationally representative serosurvey conducted duing 2017, to estimate the seroprevalence of different markers of HB infection among children aged 5-17 years in India and to assess the impact of vaccination.
METHODS: We tested sera from 8273 children for different markers of HB infection and estimated weighted age-group specific seroprevalence of children who were chronically infected (HBsAg and anti-HBc positive), and immune due to past infection (anti-HBc positive and HBsAg negative), and having serological evidence of HB vaccination (only anti-HBs positive). We compared the prevalence of serological markers among children born before (aged 11-17 years) and after (aged 5-10 years) introduction of HB-vaccine from phase-1 states.
RESULTS: Among children aged 5-8 years, 1.1% were chronic carriers, 5.3% immune due to past infection, and 23.2% vaccinated. The corresponding proportions among children aged 9-17 years were 1.1%, 8.0%, and 12.0%, respectively. In phase-1 states, children aged 5-10 years had a significantly lower prevalence of anti-HBc (4.9% vs. 7.6%, p<0.001) and higher prevalence of anti-HBs (37.7% vs. 14.7%, p<0.001) compared to children aged 11-17 years. HBsAg positivity, however, was not different in the two age groups.
CONCLUSIONS: Children born after the introduction of HB vaccination had a lower prevalence of past HBV infection and a higher prevalence of anti-HBs. The findings of our study could be considered as an interim assessment of the impact of the hepatitis B vaccine introduction in India.

PMID: 32896662 [PubMed - indexed for MEDLINE]

Immunity against diphtheria among children aged 5-17 years in India, 2017-18: a cross-sectional, population-based serosurvey.

January 26, 2021
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Immunity against diphtheria among children aged 5-17 years in India, 2017-18: a cross-sectional, population-based serosurvey.

Lancet Infect Dis. 2021 Jan 21;:

Authors: Murhekar MV, Kamaraj P, Kumar MS, Khan SA, Allam RR, Barde PV, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D, Tandale BV, Topno RK, Kumar CPG, Sabarinathan R, Bitragunta S, Grover GS, Lakshmi PVM, Mishra CM, Sadhukhan P, Sahoo PK, Singh SK, Yadav CP, Kumar R, Dutta S, Toteja GS, Gupta N, Mehendale SM, ICMR Serosurvey Group

Abstract
BACKGROUND: Diphtheria is re-emerging as a public health problem in several Indian states. Most diphtheria cases are among children older than 5 years. In this study, we aimed to estimate age-specific immunity against diphtheria in children aged 5-17 years in India.
METHODS: We used residual serum samples from a cross-sectional, population-based serosurvey for dengue infection done between June 19, 2017, and April 12, 2018, to estimate the age-group-specific seroprevalence of antibodies to diphtheria in children aged 5-17 years in India. 8309 serum samples collected from 240 clusters (122 urban and 118 rural) in 60 selected districts of 15 Indian states spread across all five geographical regions (north, northeast, east, west, and south) of India were tested for the presence of IgG antibodies against diphtheria toxoid using an ELISA. We considered children with antibody concentrations of 0·1 IU/mL or greater as immune, those with levels less than 0·01 IU/mL as non-immune (and hence susceptible to diphtheria), and those with levels in the range of 0·01 to less than 0·1 IU/mL as partially immune. We calculated the weighted proportion of children who were immune, partially immune, and non-immune, with 95% CIs, for each geographical region by age group, sex, and area of residence (urban vs rural).
FINDINGS: 29·7% (95% CI 26·3-33·4) of 8309 children aged 5-17 years were immune to diphtheria, 10·5% (8·6-12·8) were non-immune, and 59·8% (56·3-63·1) were partially immune. The proportion of children aged 5-17 years who were non-immune to diphtheria ranged from 6·0% (4·2-8·3) in the south to 16·8% (11·2-24·4) in the northeast. Overall, 9·9% (7·7-12·5) of children residing in rural areas and 13·1% (10·2-16·6) residing in urban areas were non-immune to diphtheria. A higher proportion of girls than boys were non-immune to diphtheria in the northern (17·7% [12·6-24·2] vs 7·1% [4·1-11·9]; p=0·0007) and northeastern regions (20·0% [12·9-29·8] vs 12·9% [8·6-19·0]; p=0·0035).
INTERPRETATION: The findings of our serosurvey indicate that a substantial proportion of children aged 5-17 years were non-immune or partially immune to diphtheria. Transmission of diphtheria is likely to continue in India until the immunity gap is bridged through adequate coverage of primary and booster doses of diphtheria vaccine.
FUNDING: Indian Council of Medical Research.

PMID: 33485469 [PubMed - as supplied by publisher]

Human genome diversity data reveal that L564P is the predominant TPC2 variant and a prerequisite for the blond hair associated M484L gain-of-function effect.

January 20, 2021
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Human genome diversity data reveal that L564P is the predominant TPC2 variant and a prerequisite for the blond hair associated M484L gain-of-function effect.

PLoS Genet. 2021 Jan 19;17(1):e1009236

Authors: Böck J, Krogsaeter E, Passon M, Chao YK, Sharma S, Grallert H, Peters A, Grimm C

Abstract
The endo-lysosomal two-pore channel (TPC2) has been established as an intracellular cation channel of significant physiological and pathophysiological relevance in recent years. For example, TPC2-/- mice show defects in cholesterol degradation, leading to hypercholesterinemia; TPC2 absence also results in mature-onset obesity, and a role in glucagon secretion and diabetes has been proposed. Infections with bacterial toxins or viruses e.g., cholera toxin or Ebola virus result in reduced infectivity rates in the absence of TPC2 or after pharmacological blockage, and TPC2-/- cancer cells lose their ability to migrate and metastasize efficiently. Finally, melanin production is affected by changes in hTPC2 activity, resulting in pigmentation defects and hair color variation. Here, we analyzed several publicly available genome variation data sets and identified multiple variations in the TPC2 protein in distinct human populations. Surprisingly, one variation, L564P, was found to be the predominant TPC2 isoform on a global scale. By applying endo-lysosomal patch-clamp electrophysiology, we found that L564P is a prerequisite for the previously described M484L gain-of-function effect that is associated with blond hair. Additionally, other gain-of-function variants with distinct geographical and ethnic distribution were discovered and functionally characterized. A meta-analysis of genome-wide association studies was performed, finding the polymorphisms to be associated with both distinct and overlapping traits. In sum, we present the first systematic analysis of variations in TPC2. We functionally characterized the most common variations and assessed their association with various disease traits. With TPC2 emerging as a novel drug target for the treatment of various diseases, this study provides valuable insights into ethnic and geographical distribution of TPC2 polymorphisms and their effects on channel activity.

PMID: 33465068 [PubMed - as supplied by publisher]

[Images of cholera in the South of France].

January 20, 2021
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[Images of cholera in the South of France].

Rev Prat. 2020 04;70(4):461-462

Authors: Gourevitch D

PMID: 32877111 [PubMed - indexed for MEDLINE]

Prevalence and antimicrobial profile of Shigella isolates in a tertiary care hospital of North Karnataka: A 12-year study.

January 20, 2021
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Prevalence and antimicrobial profile of Shigella isolates in a tertiary care hospital of North Karnataka: A 12-year study.

Indian J Med Microbiol. 2020 Jan-Mar;38(1):101-108

Authors: Jain PA, Kulkarni RD, Dutta S, Ganavali AS, Kalabhavi AS, Shetty PC, Shubhada C, Hosamani MA, Appannanavar SB, Hanamaraddi DR

Abstract
Context: Shigella is a common cause of bacillary dysentery. Although it is reported worldwide, the majority of the infections are seen in developing countries with Shigella flexneri being the most common isolate. Prevalence of Shigella species and their antibiotic susceptibility profiles vary according to geographic area and season.
Aims: In the present study, the epidemiology and antimicrobial profile of Shigella from stool samples received at our hospital for a period of 12 years (January 2006 to December 2017) was evaluated.
Subjects and Methods: A total of 4578 stool samples were collected from the cases of acute gastroenteritis and diarrhoea. Samples were processed for culture and sensitivity according to standard microbiological techniques. The presumptive identification of Shigella species was done using standard conventional biochemical tests and confirmed using antisera.
Results: A total of 189 (4.2%) samples yielded Shigella spp. Isolation of Shigella spp. were more frequent from males (58.2%). S. flexneri was the commonest species isolated (47.6%) followed by Shigella sonnei(11.6%), Shigella dysenteriae (4.2%) and Shigella boydii (2.1%). Non-typeable Shigella was commonly recovered. The isolates showed high resistance to ampicillin (76.7%) and co-trimoxazole (75%) while highest susceptibility was observed to ceftriaxone (79.2%).
Conclusions: S. flexneri was the most prevalent species isolated at this centre. Shigella isolates from the study showed alarming resistance to recommended antibiotics. Non-typeable Shigella accounted for 34.4% isolates. Molecular discrimination between Shigella and Escherichia coli is essential.

PMID: 32719216 [PubMed - indexed for MEDLINE]

Cholera epidemic and quarantine of open ports in Joseon in 1886.

January 20, 2021
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Cholera epidemic and quarantine of open ports in Joseon in 1886.

Uisahak. 2020 Apr;29(1):43-80

Authors: Park H

Abstract
In 1886, cholera was prevalent nationwide in Joseon. This year was not yet the time when the Joseon government officially overhauled quarantine rules to go into effect. Thus, quarantine efforts to prevent cholera varied depending on each of the three opening ports in the Joseon Dynasty. In Wonsan, officials of the three countries(Joseon, Japan and Qing) discussed ways to deal with cholera, and quarantine activities were carried out smoothly. On the other hand, Busan underwent friction and conflict between the parties over the implementation of quarantine rules within the region. When the Japanese consulate said that it would establish quarantine rules first and implement them, officials from various countries, including the Joseon Dynasty, strongly protested against the movement, saying that they did not reach prior consent. On top of that, economic interests were also affecting circumstances of port trade. In Incheon, there were differences between the home country and the local consulate over the urgent issue to be dealt with locally and the legal principles of applying the treaty. Since consular officials were not authorized to establish quarantine rules, the situation was settled into cancellation of the rules already issued there. The Japanese consul working at each port in the Joseon Dynasty suggested specific rules to develop quarantine activities. At this point, we can read Japan's intention to preempt the standard of future quarantine inspections. The enforcement of quarantine rules, however, was a matter that required consent from the Joseon official Gamri, the Acting Commissioner of the Joseon Maritime Customs and diplomats from each country. Furthermore, they had to go through the process of obtaining review and approval from their home countries if there were any problems in the operation of the treaty. The establishment and implementation of quarantine rules were complicated by interests of various players in each country concerning protection of their own citizens. Even though it was timely and the purpose of implementation was good, it could not follow through the quarantine rules as proposed by the Japanese consul at the opening port. The accumulation of quarantine experience and information at each port of Joseon in 1886 provided the foundation for the Joseon government to move toward to establish quarantine rules and implement them with the consent of each country in the following year.

PMID: 32418976 [PubMed - indexed for MEDLINE]

OXA-181-Like Carbapenemases in Klebsiella pneumoniae ST14, ST15, ST23, ST48, and ST231 from Septicemic Neonates: Coexistence with NDM-5, Resistome, Transmissibility, and Genome Diversity.

January 15, 2021
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OXA-181-Like Carbapenemases in Klebsiella pneumoniae ST14, ST15, ST23, ST48, and ST231 from Septicemic Neonates: Coexistence with NDM-5, Resistome, Transmissibility, and Genome Diversity.

mSphere. 2021 Jan 13;6(1):

Authors: Naha S, Sands K, Mukherjee S, Saha B, Dutta S, Basu S

Abstract
Studies on the epidemiology and genomes of isolates harboring OXA-48-like genes in septicemic neonates are rare. Here, isolates producing these carbapenemases which emerged and persisted in an Indian neonatal unit were characterized in terms of their resistome, transmissibility, and genome diversity. Antibiotic susceptibility and whole-genome sequencing were carried out. The sequence types, resistome, virulome, mobile genetic elements, and transmissibility of carbapenem-resistant plasmids were evaluated. Core genome analysis of isolates was shown in a global context with other OXA-48-like carbapenemase-harboring genomes, including those from neonatal studies. Eleven OXA-48-like carbapenemase-producing Klebsiella pneumoniae (bla OXA-181, n = 7 and bla OXA-232, n = 4) isolates belonging to diverse sequence types (ST14, ST15, ST23, ST48, and ST231) were identified. bla OXA-181/OXA-232 and bla NDM-5 were found in a high-risk clone, ST14 (n = 4). bla OXA-181/OXA-232 were in small, nonconjugative ColKP3 plasmids located on truncated Tn2013, whereas bla NDM-5 was in self-transmissible, conjugative IncFII plasmids, within truncated Tn125 Conjugal transfer of bla OXA-181/OXA-232 was observed in the presence of bla NDM-5 The study strains were diverse among themselves and showed various levels of relatedness with non-neonatal strains from different parts of the world and similarity with neonatal strains from Tanzania and Ghana when compared with a representative collection of carbapenemase-positive K. pneumoniae strains. We found that bla OXA-181/OXA-232-harboring isolates from a single neonatal unit had remarkably diverse genomes, ruling out clonal spread and emphasizing the extent of plasmid spreading across different STs. This study is probably the first to report the coexistence of bla OXA-181/232 and bla NDM-5 in neonatal isolates.IMPORTANCE Neonatal sepsis is a leading cause of neonatal mortality in low- and middle-income countries (LMICs). Treatment of sepsis in this vulnerable population is dependent on antimicrobials, and resistance to these life-saving antimicrobials is worrisome. Carbapenemases, enzymes produced by bacteria, can make these antimicrobials useless. Our study describes how OXA-48-like carbapenemases in neonatal septicemic Klebsiella pneumoniae shows remarkable diversity in the genomes of the strains and relatedness with strains from other parts of world and also to some neonatal outbreak strains. It is also the first to describe such resistance due to coproduction of dual carbapenemases, (OXA)-48 and New Delhi metallo-β-lactamase-5, in Klebsiella pneumoniae from neonatal settings. Carbapenemase genes situated on plasmids within high-risk international clones, as seen here, increase the ease and transfer of resistant genetic material. With the WHO treatment protocols not adequately poised to handle such infections, prompt attention to neonatal health care is required.

PMID: 33441403 [PubMed - in process]

Food Safety Challenges in Refugee Camps: What do we know?

January 8, 2021
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Food Safety Challenges in Refugee Camps: What do we know?

J Food Prot. 2021 Jan 07;:

Authors: Garsow AV, Closs G, Campbell EP, Kowalcyk B

Abstract
Refugee camps provide basic necessities such as food, water, shelter, and medical treatment for displaced persons. Unsanitary conditions in refugee camps due to overcrowding, poor sanitation systems, lack of clean water, minimal ways to cook and store food can lead to an increased risk of foodborne illness. This article reviews the limited literature on the epidemiology of foodborne illness in refugee camps, effective risk mitigation strategies and opportunities for future research. Eleven articles were identified, suggesting that research in this area is limited. Identified research focused on three pathogens - Vibrio cholerae , Salmonella spp. and hepatitis E virus - that can lead to serious diseases including cholera, salmonellosis, typhoid fever, and hepatitis E. The research demonstrated that storage and handling of clean water for personal hygiene as well as food preparation were critical components to ensuring food safety. Additionally, knowledge pertaining to best practices for hygiene and food preparation were also identified as important. Gaps in current research include the determination of the prevalence of pathogens in food sold in refugee camps as well as development of culturally relevant food safety supply chain quality management systems. More research that focuses on burden and attribution of foodborne illness as well as food safety interventions in refugee camps is necessary.

PMID: 33411925 [PubMed - as supplied by publisher]

Multiepitope Subunit Vaccine Design against COVID-19 Based on the Spike Protein of SARS-CoV-2: An In Silico Analysis.

January 7, 2021
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Multiepitope Subunit Vaccine Design against COVID-19 Based on the Spike Protein of SARS-CoV-2: An In Silico Analysis.

J Immunol Res. 2020;2020:8893483

Authors: Dar HA, Waheed Y, Najmi MH, Ismail S, Hetta HF, Ali A, Muhammad K

Abstract
The global health crisis caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, has resulted in a negative impact on human health and on social and economic activities worldwide. Researchers around the globe need to design and develop successful therapeutics as well as vaccines against the novel COVID-19 disease. In the present study, we conducted comprehensive computer-assisted analysis on the spike glycoprotein of SARS-CoV-2 in order to design a safe and potent multiepitope vaccine. In silico epitope prioritization shortlisted six HLA I epitopes and six B-cell-derived HLA II epitopes. These high-ranked epitopes were all connected to each other via flexible GPGPG linkers, and at the N-terminus side, the sequence of Cholera Toxin β subunit was attached via an EAAAK linker. Structural modeling of the vaccine was performed, and molecular docking analysis strongly suggested a positive association of a multiepitope vaccine with Toll-like Receptor 3. The structural investigations of the vaccine-TLR3 complex revealed the formation of fifteen interchain hydrogen bonds, thus validating its integrity and stability. Moreover, it was found that this interaction was thermodynamically feasible. In conclusion, our data supports the proposition that a multiepitope vaccine will provide protective immunity against COVID-19. However, further in vivo and in vitro experiments are needed to validate the immunogenicity and safety of the candidate vaccine.

PMID: 33274246 [PubMed - indexed for MEDLINE]

Pandemics and the development of scientific methods in the history of epidemiology

January 6, 2021

Colomb Med (Cali). 2020 Sep 30;51(3):e104564. doi: 10.25100/cm.v50i3.4556.

NO ABSTRACT

PMID:33402752 | PMC:PMC7744110 | DOI:10.25100/cm.v50i3.4556

The "Scourge of the Renaissance". A Short Review About Treponema pallidum infection.

January 2, 2021
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The "Scourge of the Renaissance". A Short Review About Treponema pallidum infection.

Endocr Metab Immune Disord Drug Targets. 2020;20(3):335-343

Authors: Santacroce L, Bottalico L, Topi S, Castellaneta F, Charitos IA

Abstract
BACKGROUND: There is not a time in the history when epidemics did not loom large: infectious diseases have always had civilisation and evolution-altering consequences. Throughout history, there have been a number of pandemics: cholera, bubonic plague, influenza, smallpox are some of the most brutal killers in human history. Historical accounts of pandemics clearly demonstrate that war, unhygienic conditions, social and health inequality create conditions for the transmission of infectious diseases, and existing health disparities can contribute to unequal morbidity and mortality. The Renaissance was a period of European cultural, artistic, political and economic "rebirth" following the Middle Ages, but it was also the time when new infectious disease appeared, such as Syphilis. The epidemic spread of Syphilis began between the late 15th century and early 16th century due to the increased migration of peoples across Europe. The rapid spread of venereal syphilis throughout Europe suggests the introduction of a disease into a population that had not previously been exposed. Syphilis is a type of treponematosis, which includes syphilis, bejel, yaws, and pinta, but, while syphilis is venereal disease, the others are nonvenereal. Syphilis was, at the beginning, a disease of great severity due to its novelty, as the population had no time to gain any immunity against this venereal disease.
METHODS: The purpose of this study is to investigate the origin of syphilis and the evolution of the treatments from the empiric means to the discovery of penicillin, but also to understand how this venereal disease has largely influenced human lifestyle and evolution.
CONCLUSION: The first of the three hypotheses about its origins is the Columbian hypothesis, which states that Columbus's crew acquired syphilis from Native Americans and carried it back to Europe in 1493 A. D. On the contrary, the second hypothesis (pre-Columbian) asserts that syphilis was present in Europe long before Columbus's voyage and was transferred to the New World by Columbus's men. The Unitarian theory argues that syphilis, bejel, yaws, and pinta are not separate diseases but they represent syndromes caused by slightly different strains of one organism. Nowadays, Syphilis' origin is still uncertain and remains controversial. However, the large impact on the social behavior and international public health is an important reason to investigate about its origins and how to prevent the transmission.

PMID: 31625831 [PubMed - in process]

A protracted cholera outbreak among residents in an urban setting, Nairobi county, Kenya, 2015.

January 1, 2021
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A protracted cholera outbreak among residents in an urban setting, Nairobi county, Kenya, 2015.

Pan Afr Med J. 2020;36:127

Authors: Kigen HT, Boru W, Gura Z, Githuka G, Mulembani R, Rotich J, Abdi I, Galgalo T, Githuku J, Obonyo M, Muli R, Njeru I, Langat D, Nsubuga P, Kioko J, Lowther S

Abstract
Introduction: in 2015, a cholera outbreak was confirmed in Nairobi county, Kenya, which we investigated to identify risk factors for infection and recommend control measures.
Methods: we analyzed national cholera surveillance data to describe epidemiological patterns and carried out a case-control study to find reasons for the Nairobi county outbreak. Suspected cholera cases were Nairobi residents aged >2 years with acute watery diarrhea (>4 stools/≤12 hours) and illness onset 1-14 May 2015. Confirmed cases had Vibrio cholerae isolated from stool. Case-patients were frequency-matched to persons without diarrhea (1:2 by age group, residence), interviewed using standardized questionaires. Logistic regression identified factors associated with case status. Household water was analyzed for fecal coliforms and Escherichia coli.
Results: during December 2014-June 2015, 4,218 cholera cases including 282 (6.7%) confirmed cases and 79 deaths (case-fatality rate [CFR] 1.9%) were reported from 14 of 47 Kenyan counties. Nairobi county reported 781 (19.0 %) cases (attack rate, 18/100,000 persons), including 607 (78%) hospitalisations, 20 deaths (CFR 2.6%) and 55 laboratory-confirmed cases (7.0%). Seven (70%) of 10 water samples from communal water points had coliforms; one had Escherichia coli. Factors associated with cholera in Nairobi were drinking untreated water (adjusted odds ratio [aOR] 6.5, 95% confidence interval [CI] 2.3-18.8), lacking health education (aOR 2.4, CI 1.1-7.9) and eating food outside home (aOR 2.4, 95% CI 1.2-5.7).
Conclusion: we recommend safe water, health education, avoiding eating foods prepared outside home and improved sanitation in Nairobi county. Adherence to these practices could have prevented this protacted cholera outbreak.

PMID: 32849982 [PubMed - in process]

Pandemic Vibrio cholerae shuts down site-specific recombination to retain an interbacterial defence mechanism.

December 29, 2020
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Pandemic Vibrio cholerae shuts down site-specific recombination to retain an interbacterial defence mechanism.

Nat Commun. 2020 12 07;11(1):6246

Authors: Santoriello FJ, Michel L, Unterweger D, Pukatzki S

Abstract
Vibrio cholerae is an aquatic microbe that can be divided into three subtypes: harmless environmental strains, localised pathogenic strains, and pandemic strains causing global cholera outbreaks. Each type has a contact-dependent type VI secretion system (T6SS) that kills neighbouring competitors by translocating unique toxic effector proteins. Pandemic isolates possess identical effectors, indicating that T6SS effectors may affect pandemicity. Here, we show that one of the T6SS gene clusters (Aux3) exists in two states: a mobile, prophage-like element in a small subset of environmental strains, and a truncated Aux3 unique to and conserved in pandemic isolates. Environmental Aux3 can be readily excised from and integrated into the genome via site-specific recombination, whereas pandemic Aux3 recombination is reduced. Our data suggest that environmental Aux3 acquisition conferred increased competitive fitness to pre-pandemic V. cholerae, leading to grounding of the element in the chromosome and propagation throughout the pandemic clade.

PMID: 33288753 [PubMed - indexed for MEDLINE]

Geographical distribution and antibiotics susceptibility patterns of toxigenic Vibrio cholerae isolates from Kisumu County, Kenya.

December 29, 2020
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Geographical distribution and antibiotics susceptibility patterns of toxigenic Vibrio cholerae isolates from Kisumu County, Kenya.

Afr J Prim Health Care Fam Med. 2020 Dec 08;12(1):e1-e6

Authors: Awuor SO, Omwenga EO, Daud II

Abstract
BACKGROUND: Multiple drug resistance has become a major threat to the treatment of cholera. Recent studies in Kenya have described the epidemiology, especially the risk factors, of cholera; however, there is little information on the phenotypic and drug susceptibility patterns of Vibrio cholerae (V. cholerae) in outbreaks that in the recent past have occurred in western Kenya.
AIM: To characterise and determine the antibiotics' susceptibility profiling of toxigenic V. cholerae isolates from Kisumu County.
SETTING: The project was conducted in Kisumu County, Kenya.
METHODS: A total of 119 V. cholerae O1, biotype El Tor, isolates collected during 2017 cholera outbreak in Kisumu County were used for this study. The samples were cultured on thiosulphate-citrate-bile salts sucrose (TCBS) agar and biochemical tests were carried out using standard procedures. Susceptibility tests were conducted by using various conventional antibiotics against standard procedures.
RESULTS: Of the 119 isolates, 101 were confirmed to be V. cholerae belonging to serotypes Inaba and Ogawa, with Inaba being the predominant serotype (73.95%). The isolates were susceptible to ciprofloxacin (100%), ofloxacin (100%), gentamycin (100%), doxycycline (99%), ceftriaxone (99%) and streptomycin (96.04%) antimicrobials, and resistant to erythromycin (53.47%), amoxicillin (64.4%), nalidixic acid (83.2%) and ampicillin (89.11%), with high resistance to cotrimoxazole (99%) and tetracycline (97%).
CONCLUSION: Vibrio cholerae was resistant to multiple antibiotics, including those commonly used in the management of cholera. Taken together, there is a need to carry out regular surveillance on antimicrobial drug resistance during outbreaks.

PMID: 33354982 [PubMed - in process]

Evaluation of community based surveillance in the Rohingya refugee camps in Cox's Bazar, Bangladesh, 2019

December 28, 2020

PLoS One. 2020 Dec 23;15(12):e0244214. doi: 10.1371/journal.pone.0244214. eCollection 2020.

ABSTRACT

BACKGROUND: Following an influx of an estimated 742,000 Rohingya refugees in Bangladesh, Médecins sans Frontières (MSF) established an active indicator-based Community Based Surveillance (CBS) in 13 sub-camps in Cox's Bazar in August 2017. Its objective was to detect epidemic prone diseases early for rapid response. We describe the surveillance, alert and response in place from epidemiological week 20 (12 May 2019) until 44 (2 November 2019).

METHODS: Suspected cases were identified through passive health facility surveillance and active indicator-based CBS. CBS-teams conducted active case finding for suspected cases of acute watery diarrhea (AWD), acute jaundice syndrome (AJS), acute flaccid paralysis (AFP), dengue, diphtheria, measles and meningitis. We evaluate the following surveillance system attributes: usefulness, Positive Predictive Value (PPV), timeliness, simplicity, flexibility, acceptability, representativeness and stability.

RESULTS: Between epidemiological weeks 20 and 44, an average of 97,340 households were included in the CBS per surveillance cycle. Household coverage reached over 85%. Twenty-one RDT positive cholera cases and two clusters of AWD were identified by the CBS and health facility surveillance that triggered the response mechanism within 12 hours. The PPV of the CBS varied per disease between 41.7%-100%. The CBS required 354 full-time staff in 10 different roles. The CBS was sufficiently flexible to integrate dengue surveillance. The CBS was representative of the population in the catchment area due to its exhaustive character and high household coverage. All households consented to CBS participation, showing acceptability.

DISCUSSION: The CBS allowed for timely response but was resource intensive. Disease trends identified by the health facility surveillance and suspected diseases trends identified by CBS were similar, which might indicate limited additional value of the CBS in a dense and stable setting such as Cox's Bazar. Instead, a passive community-event-based surveillance mechanism combined with health facility-based surveillance could be more appropriate.

PMID:33362236 | PMC:PMC7757896 | DOI:10.1371/journal.pone.0244214

Delineating and Analyzing Locality-Level Determinants of Cholera, Haiti.

December 23, 2020
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Delineating and Analyzing Locality-Level Determinants of Cholera, Haiti.

Emerg Infect Dis. 2021 Jan;27(1):170-181

Authors: Griffiths K, Moise K, Piarroux M, Gaudart J, Beaulieu S, Bulit G, Marseille JP, Jasmin PM, Namphy PC, Henrys JH, Piarroux R, Rebaudet S

Abstract
Centre Department, Haiti, was the origin of a major cholera epidemic during 2010-2019. Although no fine-scale spatial delineation is officially available, we aimed to analyze determinants of cholera at the local level and identify priority localities in need of interventions. After estimating the likely boundaries of 1,730 localities by using Voronoi polygons, we mapped 5,322 suspected cholera cases reported during January 2015-September 2016 by locality alongside environmental and socioeconomic variables. A hierarchical clustering on principal components highlighted 2 classes with high cholera risk: localities close to rivers and unimproved water sources (standardized incidence ratio 1.71, 95% CI 1.02-2.87; p = 0.04) and urban localities with markets (standardized incidence ratio 1.69, 95% CI 1.25-2.29; p = 0.0006). Our analyses helped identify and characterize areas where efforts should be focused to reduce vulnerability to cholera and other waterborne diseases; these methods could be used in other contexts.

PMID: 33350917 [PubMed - as supplied by publisher]

Vibrio cholerae O1 transmission in Bangladesh: insights from a nationally representative serosurvey.

December 22, 2020
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Vibrio cholerae O1 transmission in Bangladesh: insights from a nationally representative serosurvey.

Lancet Microbe. 2020 Dec;1(8):e336-e343

Authors: Azman AS, Lauer SA, Bhuiyan TR, Luquero FJ, Leung DT, Hegde ST, Harris JB, Paul KK, Khaton F, Ferdous J, Lessler J, Salje H, Qadri F, Gurley ES

Abstract
Background: Pandemic Vibrio cholerae from cholera-endemic countries around the Bay of Bengal regularly seed epidemics globally. Without reducing cholera in these countries, including Bangladesh, global cholera control might never be achieved. Little is known about the geographical distribution and magnitude of V cholerae O1 transmission nationally. We aimed to describe infection risk across Bangladesh, making use of advances in cholera seroepidemiology, therefore overcoming many of the limitations of current clinic-based surveillance.
Methods: We tested serum samples from a nationally representative serosurvey in Bangladesh with eight V cholerae-specific assays. Using these data with a machine-learning model previously validated within a cohort of confirmed cholera cases and their household contacts, we estimated the proportion of the population with evidence of infection by V cholerae O1 in the previous year (annual seroincidence) and used Bayesian geostatistical models to create high-resolution national maps of infection risk.
Findings: Between Oct 16, 2015, and Jan 24, 2016, we obtained and tested serum samples from 2930 participants (707 households) in 70 communities across Bangladesh. We estimated national annual seroincidence of V cholerae O1 infection of 17·3% (95% CI 10·5-24·1). Our high-resolution maps showed large heterogeneity of infection risk, with community-level annual infection risk within the sampled population ranging from 4·3% to 62·9%. Across Bangladesh, we estimated that 28·1 (95% CI 17·1-39·2) million infections occurred in the year before the survey. Despite having an annual seroincidence of V cholerae O1 infection lower than much of Bangladesh, Dhaka (the capital of Bangladesh and largest city in the country) had 2·0 (95% CI 0·6-3·9) million infections during the same year, primarily because of its large population.
Interpretation: Serosurveillance provides an avenue for identifying areas with high V cholerae O1 transmission and investigating key risk factors for infection across geographical scales. Serosurveillance could serve as an important method for countries to plan and monitor progress towards 2030 cholera elimination goals.
Funding: The Bill & Melinda Gates Foundation, National Institutes of Health, and US Centers for Disease Control and Prevention.

PMID: 33345203 [PubMed]

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