Recent Cholera Publications on PubMed

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Impact of Annual Bacterial Epizootics on Albatross Population on a Remote Island.

July 27, 2020
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Impact of Annual Bacterial Epizootics on Albatross Population on a Remote Island.

Ecohealth. 2020 Jul 23;:

Authors: Jaeger A, Gamble A, Lagadec E, Lebarbenchon C, Bourret V, Tornos J, Barbraud C, Lemberger K, Delord K, Weimerskirch H, Thiebot JB, Boulinier T, Tortosa P

Abstract
The reduced species richness typical of oceanic islands provides an interesting environmental setup to examine in natura the epidemiological dynamics of infectious agents with potential implications for public health and/or conservation. On Amsterdam Island (Indian Ocean), recurrent die-offs of Indian yellow-nosed albatross (Thalassarche carteri) nestlings have been attributed to avian cholera, caused by the bacterium Pasteurella multocida. In order to help implementing efficient measures for the control of this disease, it is critical to better understand the local epidemiology of P. multocida and to examine its inter- and intra-annual infection dynamics. We evaluated the infection status of 264 yellow-nosed albatrosses over four successive breeding seasons using a real-time PCR targeting P. multocida DNA from cloacal swabs. Infection prevalence patterns revealed an intense circulation of P. multocida throughout the survey, with a steady but variable increase in infection prevalence within each breeding season. These epizootics were associated with massive nestling dies-offs, inducing very low fledging successes (≤ 20%). These results suggest important variations in the transmission dynamics of this pathogen. These findings and the developed PCR protocol have direct applications to guide future research and refine conservation plans aiming at controlling the disease.

PMID: 32705577 [PubMed - as supplied by publisher]

Transmission dynamics of cholera with hyperinfectious and hypoinfectious vibrios: mathematical modelling and control strategies.

July 27, 2020
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Transmission dynamics of cholera with hyperinfectious and hypoinfectious vibrios: mathematical modelling and control strategies.

Math Biosci Eng. 2019 05 16;16(5):4339-4358

Authors: Lin JZ, Xu R, Tian XH

Abstract
Cholera is a common infectious disease caused by Vibrio cholerae, which has different infectivity. In this paper, we propose a cholera model with hyperinfectious and hypoinfectious vibrios, in which both human-to-human and environment-to-human transmissions are considered. By analyzing the characteristic equations, the local stability of disease-free and endemic equilibria is established. By using Lyapunov functionals and LaSalle's invariance principle, it is verified that the global threshold dynamics of the model can be completely determined by the basic reproduction number. Numerical simulations are carried out to illustrate the corresponding theoretical results and describe the cholera outbreak in Haiti. The study of optimal control helps us seek cost-effective solutions of time-dependent control strategies against cholera outbreaks, which shows that control strategies, such as vaccination and sanitation, should be taken at the very beginning of the outbreak and become less necessary after a certain period.

PMID: 31499665 [PubMed - indexed for MEDLINE]

Oral Defense: How Oral Rehydration Solutions Revolutionized the Treatment of Toxigenic Diarrhea.

July 23, 2020
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Oral Defense: How Oral Rehydration Solutions Revolutionized the Treatment of Toxigenic Diarrhea.

Dig Dis Sci. 2020 02;65(2):345-348

Authors: Kaunitz JD

PMID: 31900719 [PubMed - indexed for MEDLINE]

Cholera in travellers: a systematic review.

July 23, 2020
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Cholera in travellers: a systematic review.

J Travel Med. 2019 Dec 23;26(8):

Authors: Connor BA, Dawood R, Riddle MS, Hamer DH

Abstract
Exposure to cholera is a risk for individuals and groups travelling to endemic areas, and the bacteria can be imported to cholera-free countries by returning travellers. This systematic review of the literature describes the circumstances in which cholera infection can occur in travellers and considers the possible value of the cholera vaccine for prevention in travellers. PubMed and EMBASE were searched for case reports of cholera or diarrhoea among travellers, with date limits of 1 January 1990-30 April 2018. Search results were screened to exclude the following articles: diarrhoea not caused by cholera, cholera in animals, intentional cholera infection in humans, non-English articles and publications on epidemics that did not report clinical details of individual cases and publications of cases pre-dating 1990. Articles were reviewed through descriptive analytic methods and information summarized. We identified 156 cases of cholera imported as a consequence of travel, and these were reviewed for type of traveller, source country, serogroup of cholera, treatment and outcomes. The case reports retrieved in the search did not report consistent levels of detail, making it difficult to synthesize data across reports and draw firm conclusions from the data. This clinical review sheds light on the paucity of actionable published data regarding the risk of cholera in travellers and identifies a number of gaps that should drive additional effort. Further information is needed to better inform evidence-based disease prevention strategies, including vaccination for travellers visiting areas of cholera risk. Modifications to current vaccination recommendations to include or exclude current or additional traveller populations may be considered as additional risk data become available. The protocol for this systematic review is registered with PROSPERO (registration number: 122797).

PMID: 31804684 [PubMed - indexed for MEDLINE]

Climate, Infectious Disease and Health: An Interdisciplinary Perspective: A colloquium was convened by the American Academy of Microbiology to discuss research issues relating to the effects of climate on the incidence and distribution of infectious...

July 21, 2020

Climate, Infectious Disease and Health: An Interdisciplinary Perspective: A colloquium was convened by the American Academy of Microbiology to discuss research issues relating to the effects of climate on the incidence and distribution of infectious disease. The colloquium was held in Montego Bay, Jamaica, June 20–22, 1997.

Book. 1998

Authors: Colwell RR, Patz JA

Abstract
A colloquium was convened by the American Academy of Microbiology to discuss research issues relating to the effects of climate on the incidence and distribution of infectious disease. The colloquium was held in Montego Bay, Jamaica, June 20–22, 1997. The principal findings of the colloquium are summarized below. The global infectious disease burden exceeds several hundred million cases each year, and infectious diseases are estimated to account for one-third of annual human mortality. For many infectious diseases, principally those that are vectorborne, there is a significant amount of data relating diseases incidence to climate or weather factors. With the increasing accumulation of satellite data, a better understanding is emerging of the complex interrelations among weather and climate conditions and the survival and spread of pathogenic microorganisms and disease vectors and hosts. Annual rainfall and temperature averages are important parameters in the demarcation of bioclimate envelopes within which the occurrence of many infectious diseases is concentrated. These factors also have significant effects on variables, such as vector population size, which are related to disease outbreaks and epidemics. Although more is known about the effects of weather and climate conditions on the prevalence of vectorborne disease, there are important links between these factors and the occurrence of waterborne, airborne, soilborne, and foodborne diseases. Large-scale weather disturbances like El Niño can have a dramatic impact on the incidence of many infectious diseases, such as malaria and Rift Valley fever. Scientists have discovered numerous connections between the 1991–1995 El Niño and increases in the incidence of diseases, including cholera and hantavirus pulmonary syndrome. El Niño-related increases in sea-surface temperature and sea-surface height in the Bay of Bengal have been associated with a rise in the number of cholera cases in Bangladesh. Recent findings from the 1997–98 El Niño are providing corroborating evidence for a causal relationship between extreme weather events and disease outbreaks. Better quality and more comprehensive data sets are needed to improve the current understanding of how weather and climate affect the prevalence and occur-rence of infectious disease. This information is essential for developing accurate predictive models of disease outbreaks. Research on climate-disease links is interdisciplinary in scope and includes microbiology, epidemiology, ecology, oceanography, climatology, atmospheric sciences, and marine biology. Progress needs to be made in making data sets more accessible to researchers in these and other disciplines.


PMID: 32687286

Assessment of Bone Turnover Biomarkers in Lead-Battery Workers with Long-Term Exposure to Lead.

July 20, 2020

Assessment of Bone Turnover Biomarkers in Lead-Battery Workers with Long-Term Exposure to Lead.

Int J Occup Environ Med. 2020 07;11(3):140-147

Authors: Kalahasthi R, Barman T, Bagepally BS

Abstract
BACKGROUND: The major portion of lead in the body resides in skeletal system. The bone turnover affects the release of lead into the circulation from bones. The bone turnover biomarkers (BTM) in lead-battery workers with long-term exposure to lead have not been explored yet.
OBJECTIVE: To evaluate the BTM (formation and resorption) in lead-battery workers with long-term exposure to lead in lead-battery manufacturing plant.
METHODS: 176 male lead-exposed workers and 80 matched comparison group were studied. All participants were examined for blood lead levels (BLLs), bone formation biomarkers- serum osteocalcin (OC), alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BALP)-and bone resorption biomarkers-serum pyridinoline (PYD), deoxypyridinoline (DPYD), tartarate-resistant acid phosphatase-5b (TRACP-5b), and urinary hydroxyproline (UHYP).
RESULTS: We found a significantly higher bone formation biomarkers such as BALP (p=0.007) and bone resorption biomarkers, eg, PYD (p=0.048), TRCAP-5b (p=0.001), and UHYP (p=0.001) in lead-exposed workers. A significant (p=0.041) negative correlation (ρ ‑0.128) was noted between BLLs and OC. A significant positive correlation was noted between BLLs and TRACP-5b (ρ 0.176, p=0.005) and UHYP (ρ 0.258, p=0.004). Serum OC (p=0.040) and UHYP (p=0.015) levels changed significantly with BLL level. Bone resorption biomarkers levels- PYD, TRACP-5b, and BALP-were higher among those with higher BLLs levels. The duration of exposure was significantly associated with BALP (p=0.037), DPYD (p=0.016), TRACP-5b (p=0.001), and UHYP (p=0.002) levels.
CONCLUSION: Long-term lead exposure affects the bone turnover.

PMID: 32683426 [PubMed - as supplied by publisher]

Toxigenic Vibrio cholerae evolution and establishment of reservoirs in aquatic ecosystems.

July 17, 2020
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Toxigenic Vibrio cholerae evolution and establishment of reservoirs in aquatic ecosystems.

Proc Natl Acad Sci U S A. 2020 04 07;117(14):7897-7904

Authors: Mavian C, Paisie TK, Alam MT, Browne C, Beau De Rochars VM, Nembrini S, Cash MN, Nelson EJ, Azarian T, Ali A, Morris JG, Salemi M

Abstract
The spread of cholera in the midst of an epidemic is largely driven by direct transmission from person to person, although it is well-recognized that Vibrio cholerae is also capable of growth and long-term survival in aquatic ecosystems. While prior studies have shown that aquatic reservoirs are important in the persistence of the disease on the Indian subcontinent, an epidemiological view postulating that locally evolving environmental V. cholerae contributes to outbreaks outside Asia remains debated. The single-source introduction of toxigenic V. cholerae O1 in Haiti, one of the largest outbreaks occurring this century, with 812,586 suspected cases and 9,606 deaths reported through July 2018, provided a unique opportunity to evaluate the role of aquatic reservoirs and assess bacterial transmission dynamics across environmental boundaries. To this end, we investigated the phylogeography of both clinical and aquatic toxigenic V. cholerae O1 isolates and show robust evidence of the establishment of aquatic reservoirs as well as ongoing evolution of V. cholerae isolates from aquatic sites. Novel environmental lineages emerged from sequential population bottlenecks, carrying mutations potentially involved in adaptation to the aquatic ecosystem. Based on such empirical data, we developed a mixed-transmission dynamic model of V. cholerae, where aquatic reservoirs actively contribute to genetic diversification and epidemic emergence, which underscores the complexity of transmission pathways in epidemics and endemic settings and the need for long-term investments in cholera control at both human and environmental levels.

PMID: 32229557 [PubMed - indexed for MEDLINE]

Sheltering in Place in a Xenophobic Climate: COVID-19 and Children in Immigrant Families.

July 16, 2020
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Sheltering in Place in a Xenophobic Climate: COVID-19 and Children in Immigrant Families.

Pediatrics. 2020 07;146(1):

Authors: Cholera R, Falusi OO, Linton JM

PMID: 32345687 [PubMed - indexed for MEDLINE]

Spatial dynamics and the basic reproduction number of the 1991-1997 Cholera epidemic in Peru.

July 15, 2020
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Spatial dynamics and the basic reproduction number of the 1991-1997 Cholera epidemic in Peru.

PLoS Negl Trop Dis. 2020 Jul;14(7):e0008045

Authors: Smirnova A, Sterrett N, Mujica OJ, Munayco C, Suárez L, Viboud C, Chowell G

Abstract
After being cholera free for over 100 years, Peru experienced an unprecedented epidemic of Vibrio cholerae O1 that began in 1991 and generated multiple waves of disease over several years. We developed a mechanistic transmission model that accounts for seasonal variation in temperature to estimate spatial variability in the basic reproduction number ([Formula: see text]), the initial concentration of vibrios in the environment, and cholera reporting rates. From 1991-1997, cholera spread following a multi-wave pattern, with weekly incidence concentrated during warm seasons. The epidemic first hit the coastal departments of Peru and subsequently spread through the highlands and jungle regions. The correlation between model predictions and observations was high (range in R2: 58% to 97%). Department-level population size and elevation explained significant variation in spatial-temporal transmission patterns. The overall R0 across departments was estimated at 2.1 (95% CI: 0.8,7.3), high enough for sustained transmission. Geographic-region level [Formula: see text] varied substantially from 2.4 (95% CI: 1.1, 7.3) for the coastal region, 1.9 (0.7, 6.4) for the jungle region, and 1.5 (0.9, 2.2) for the highlands region. At the department level, mean [Formula: see text] ranged from 0.8 to 6.9. Department-level [Formula: see text] were correlated with overall observed attack rates (Spearman ρ = 0.59, P = 0.002), elevation (ρ = -0.4, P = 0.04), and longitude (ρ = -0.6, P = 0.004). We find that both [Formula: see text] and the initial concentration of vibrios were higher in coastal departments than other departments. Reporting rates were low, consistent with a substantial fraction of asymptomatic or mild cases associated with the El Tor cholera biotype. Our results suggest that cholera vibrios, autochthonous to plankton in the natural aquatic environment, may have triggered outbreaks in multiple coastal locations along the Pacific coast of Peru. Our methodology could be useful to investigate multi-wave epidemics of cholera and could be extended to conduct near real-time forecasts and investigate the impact of vaccination strategies.

PMID: 32663235 [PubMed - as supplied by publisher]

A cholera transmission model incorporating the impact of medical resources.

July 14, 2020
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A cholera transmission model incorporating the impact of medical resources.

Math Biosci Eng. 2019 06 06;16(5):5226-5246

Authors: Yang CY, Wang J

Abstract
We propose a mathematical model for the transmission dynamics of cholera under the impact of available medical resources. The model describes the interaction between the human hosts and the pathogenic bacteria and incorporates both the environment-to-human and human-to-human transmission routes. We conduct a rigorous equilibrium analysis to the model and establish the global asymptotic stability of the disease-free equilibrium when R0 ≤ 1 and that of the endemic equilibrium when R0 > 1. As a realistic case study, we apply our model to the Yemen cholera outbreak during 2017-2018. By fitting our simulation results to the epidemic data published by the World Health Organization, we find that different levels of disease prevalence and severity are linked to different geographical regions in this country and that cholera prevention and intervention efforts should be implemented strategically with respect to these regions in Yemen.

PMID: 31499710 [PubMed - indexed for MEDLINE]

Surgeons, plague, and leadership: A historical mantle to carry forward.

July 7, 2020
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Surgeons, plague, and leadership: A historical mantle to carry forward.

Am J Surg. 2020 08;220(2):298-299

Authors: Barr J, Hwang ES, Shortell CK

PMID: 32386712 [PubMed - indexed for MEDLINE]

Deciphering the possible role of ctxB7 allele on higher production of cholera toxin by Haitian variant Vibrio cholerae O1.

July 7, 2020
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Deciphering the possible role of ctxB7 allele on higher production of cholera toxin by Haitian variant Vibrio cholerae O1.

PLoS Negl Trop Dis. 2020 04;14(4):e0008128

Authors: Naha A, Mandal RS, Samanta P, Saha RN, Shaw S, Ghosh A, Chatterjee NS, Dutta P, Okamoto K, Dutta S, Mukhopadhyay AK

Abstract
Cholera continues to be an important public health concern in developing countries where proper hygiene and sanitation are compromised. This severe diarrheal disease is caused by the Gram-negative pathogen Vibrio cholerae belonging to serogroups O1 and O139. Cholera toxin (CT) is the prime virulence factor and is directly responsible for the disease manifestation. The ctxB gene encodes cholera toxin B subunit (CTB) whereas the A subunit (CTA) is the product of ctxA gene. Enzymatic action of CT depends on binding of B pentamers to the lipid-based receptor ganglioside GM1. In recent years, emergence of V. cholerae Haitian variant strains with ctxB7 allele and their rapid spread throughout the globe has been linked to various cholera outbreaks in Africa and Asia. These strains produce classical type (WT) CTB except for an additional mutation in the signal sequence region where an asparagine (N) residue replaces a histidine (H) at the 20th amino acid position (H20N) of CTB precursor (pre-CTB). Here we report that Haitian variant V. cholerae O1 strains isolated in Kolkata produced higher amount of CT compared to contemporary O1 El Tor variant strains under in vitro virulence inducing conditions. We observed that the ctxB7 allele, itself plays a pivotal role in higher CT production. Based on our in silico analysis, we hypothesized that higher accumulation of toxin subunits from ctxB7 allele might be attributed to the structural alteration at the CTB signal peptide region of pre-H20N CTB. Overall, this study provides plausible explanation regarding the hypertoxigenic phenotype of the Haitian variant strains which have spread globally, possibly through positive selection for increased pathogenic traits.

PMID: 32236098 [PubMed - indexed for MEDLINE]

Burden of typhoid fever and cholera: similarities and differences. Prevention strategies for European travelers to endemic/epidemic areas.

July 4, 2020
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Burden of typhoid fever and cholera: similarities and differences. Prevention strategies for European travelers to endemic/epidemic areas.

J Prev Med Hyg. 2019 Dec;60(4):E271-E285

Authors: Amicizia D, Micale RT, Pennati BM, Zangrillo F, Iovine M, Lecini E, Marchini F, Lai PL, Panatto D

Abstract
The burden of diarrheal diseases is very high, accounting for 1.7 to 5 billion cases per year worldwide. Typhoid fever (TF) and cholera are potentially life-threatening infectious diseases, and are mainly transmitted through the consumption of food, drink or water that have been contaminated by the feces or urine of subjects excreting the pathogen. TF is mainly caused by Salmonella typhi, whereas cholera is caused by intestinal infection by the toxin-producing bacterium Vibrio cholerae. These diseases typically affect low- and middle-income countries where housing is overcrowded and water and sanitation are poor, or where conflicts or natural disasters have led to the collapse of the water, sanitation and healthcare systems. Mortality is higher in children under 5 years of age. Regarding their geographical distribution, TF has a high incidence in sub-Saharan Africa, India and south-east Asia, while cholera has a high incidence in a few African countries, particularly in the Horn of Africa and the Arabian Peninsula. In the fight against these diseases, preventive measures are fundamental. With modern air travel, transmissible diseases can spread across continents and oceans in a few days, constituting a threat to global public health. Nowadays, people travel for many reasons, such as tourism and business. Several surveys have shown that a high proportion of travelers lack adequate information on safety issues, such as timely vaccination and prophylactic medications. The main objective of this overview is to provide information to help European travelers to stay healthy while abroad, and thus also to reduce the potential importation of these diseases and their consequent implications for public health and society. The preventive measures to be implemented in the case of travel to countries where these diseases are still endemic are well known: the adoption of safe practices and vaccinations. It is important to stress that an effective preventive strategy should be based both on vaccinations and on hygiene travel guidelines. Furthermore, the emergence of multidrug-resistant strains is becoming a serious problem in the clinical treatment of these diseases. For this reason, vaccination is the main solution.

PMID: 31967084 [PubMed - indexed for MEDLINE]

Diarrhoeal disease and subsequent risk of death in infants and children residing in low-income and middle-income countries: analysis of the GEMS case-control study and 12-month GEMS-1A follow-on study.

July 4, 2020
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Diarrhoeal disease and subsequent risk of death in infants and children residing in low-income and middle-income countries: analysis of the GEMS case-control study and 12-month GEMS-1A follow-on study.

Lancet Glob Health. 2020 02;8(2):e204-e214

Authors: Levine MM, Nasrin D, Acácio S, Bassat Q, Powell H, Tennant SM, Sow SO, Sur D, Zaidi AKM, Faruque ASG, Hossain MJ, Alonso PL, Breiman RF, O'Reilly CE, Mintz ED, Omore R, Ochieng JB, Oundo JO, Tamboura B, Sanogo D, Onwuchekwa U, Manna B, Ramamurthy T, Kanungo S, Ahmed S, Qureshi S, Quadri F, Hossain A, Das SK, Antonio M, Saha D, Mandomando I, Blackwelder WC, Farag T, Wu Y, Houpt ER, Verweiij JJ, Sommerfelt H, Nataro JP, Robins-Browne RM, Kotloff KL

Abstract
BACKGROUND: The Global Enteric Multicenter Study (GEMS) was a 3-year case-control study that measured the burden, aetiology, and consequences of moderate-to-severe diarrhoea (MSD) in children aged 0-59 months. GEMS-1A, a 12-month follow-on study, comprised two parallel case-control studies, one assessing MSD and the other less-severe diarrhoea (LSD). In this report, we analyse the risk of death with each diarrhoea type and the specific pathogens associated with fatal outcomes.
METHODS: GEMS was a prospective, age-stratified, matched case-control study done at seven sites in Africa and Asia. Children aged 0-59 months with MSD seeking care at sentinel health centres were recruited along with one to three randomly selected matched community control children without diarrhoea. In the 12-month GEMS-1A follow-on study, children with LSD and matched controls, in addition to children with MSD and matched controls, were recruited at six of the seven sites; only cases of MSD and controls were enrolled at the seventh site. We compared risk of death during the period between enrolment and one follow-up household visit done about 60 days later (range 50-90 days) in children with MSD and LSD and in their respective controls. Approximately 50 pathogens were detected using, as appropriate, classic bacteriology, immunoassays, gel-based PCR and reverse transcriptase PCR, and quantitative real-time PCR (qPCR). Specimens from a subset of GEMS cases and controls were also tested by a TaqMan Array Card that compartmentalised probe-based qPCR for 32 enteropathogens.
FINDINGS: 223 (2·0%) of 11 108 children with MSD and 43 (0·3%) of 16 369 matched controls died between study enrolment and the follow-up visit at about 60 days (hazard ratio [HR] 8·16, 95% CI 5·69-11·68, p<0·0001). 12 (0·4%) of 2962 children with LSD and seven (0·2%) of 4074 matched controls died during the follow-up period (HR 2·78, 95% CI 0·95-8·11, p=0·061). Risk of death was lower in children with dysenteric MSD than in children with non-dysenteric MSD (HR 0·20, 95% CI 0·05-0·87, p=0·032), and lower in children with LSD than in those with non-dysenteric MSD (HR 0·29, 0·14-0·59, p=0·0006). In children younger than 24 months with MSD, infection with typical enteropathogenic Escherichia coli, enterotoxigenic E coli encoding heat-stable toxin, enteroaggregative E coli, Shigella spp (non-dysentery cases), Aeromonas spp, Cryptosporidium spp, and Entamoeba histolytica increased risk of death. Of 61 deaths in children aged 12-59 months with non-dysenteric MSD, 31 occurred among 942 children qPCR-positive for Shigella spp and 30 deaths occurred in 1384 qPCR-negative children (HR 2·2, 95% CI 1·2-3·9, p=0·0090), showing that Shigella was strongly associated with increased risk of death.
INTERPRETATION: Risk of death is increased following MSD and, to a lesser extent, LSD. Considering there are approximately three times more cases of LSD than MSD in the population, more deaths are expected among children with LSD than in those with MSD. Because the major attributable LSD-associated and MSD-associated pathogens are the same, implementing vaccines and rapid diagnosis and treatment interventions against these major pathogens are rational investments.
FUNDING: Bill & Melinda Gates Foundation.

PMID: 31864916 [PubMed - indexed for MEDLINE]

Cholera outbreak in Addis Ababa, Ethiopia: A case-control study.

July 3, 2020
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Cholera outbreak in Addis Ababa, Ethiopia: A case-control study.

PLoS One. 2020;15(7):e0235440

Authors: Dinede G, Abagero A, Tolosa T

Abstract
BACKGROUND: Cholera remains a significant public health problem in more than one-third of the countries of the world. Cholera outbreak has become more common in Addis Ababa particularly in the rainy seasons; however, there is a paucity of data on risk factors associated with cholera outbreaks rendering interventions difficult. We investigated the outbreak to identify its etiology, source, risk factors and in order to control the outbreak.
METHODS: We compared cases with health center-based unmatched controls (1:2). Cases were patients aged ≥5 years with acute watery diarrhea, with or without vomiting while controls were persons aged ≥5 years without history of acute watery diarrhea. We interviewed our study participants using structured questionnaire to collect demographic and cholera risk factors data. We described the outbreak over time, and then tested our hypotheses using unconditional logistic regression.
RESULTS: The outbreak began on 7 September, 2017 reaching its peak on 23 September, 2017 and ended on 01 October, 2017. We identified a total of 25 cases (Median age: 38 years; IQR: 20 years) and recruited 50 controls (Median age: 35 years; IQR: 29 years). All case-patients had acute watery diarrhea and dehydration requiring intravenous fluids. All cases were admitted to cholera treatment center but there were no deaths. Stool and water samples yielded isolates of Vibrio cholerae O1 of serological subtype Ogawa. Consumption of contaminated holy water (AOR: 20.5, 95%CI: 3.50, 119.61) and raw vegetables (AOR: 15.3, 95%CI: 3, 81.51) were independent risk factors whereas washing hands with soap after visiting latrine (AOR: 0.04, 95%CI: 0.01, 0.25) was independent protective factor.
CONCLUSION: Our findings demonstrated cholera foodborne transmission via consumption of raw vegetables, and its waterborne transmission via consumption of contaminated holy water. Washing hands with soap after visiting latrine was protective. We recommended cooking of vegetables and promoting hand washing.

PMID: 32614915 [PubMed - as supplied by publisher]

Authors' response.

July 3, 2020
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Authors' response.

Indian J Med Res. 2020 May;151(5):496

Authors: Gupta N, Potdar V, Praharaj I, Giri S, Sapkal G, Yadav P, Choudhary ML, Dar L, Sugunan AP, Kaur H, Munivenkatappa A, Shastri J, Kaveri K, Dutta S, Malhotra B, Jain A, Nagamani K, Shantala GB, Raut S, Vegad MM, Sharma A, Choudhary A, Brijwa M, Balakrishnan A, Manjunatha J, Pathak M, Srinivasan S, Banu H, Sharma H, Jain P, Sunita P, Ambica R, Fageria B, Patel D, Rajbongshi G, Vijay N, Narayan J, Aggarwal N, Nagar A, Gangakhedkar RR, Abraham P

PMID: 32611921 [PubMed - in process]

Healthcare workers & SARS-CoV-2 infection in India: A case-control investigation in the time of COVID-19.

July 3, 2020
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Healthcare workers & SARS-CoV-2 infection in India: A case-control investigation in the time of COVID-19.

Indian J Med Res. 2020 May;151(5):459-467

Authors: Chatterjee P, Anand T, Singh KJ, Rasaily R, Singh R, Das S, Singh H, Praharaj I, Gangakhedkar RR, Bhargava B, Panda S

Abstract
Background & objectives: Healthcare workers (HCWs) are at an elevated risk of contracting COVID-19. While intense occupational exposure associated with aerosol-generating procedures underlines the necessity of using personal protective equipment (PPE) by HCWs, high-transmission efficiency of the causative agent [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] could also lead to infections beyond such settings. Hydroxychloroquine (HCQ), a repurposed antimalarial drug, was empirically recommended as prophylaxis by the National COVID-19 Task Force in India to cover such added risk. Against this background, the current investigation was carried out to identify the factors associated with SARS-CoV-2 infection among HCWs in the country.
Methods: A case-control design was adopted and participants were randomly drawn from the countrywide COVID-19 testing data portal maintained by the ICMR. The test results and contact details of HCWs, diagnosed as positive (cases) or negative (controls) for SARS-CoV-2 using real-time reverse transcription-polymerase chain reaction (qRT-PCR), were available from this database. A 20-item brief-questionnaire elicited information on place of work, procedures conducted and use of PPE.
Results: Compared to controls, cases were slightly older (34.7 vs. 33.5 yr) and had more males (58 vs. 50%). In multivariate analyses, HCWs performing endotracheal intubation had higher odds of being SARS-CoV-2 infected [adjusted odds ratio (AOR): 4.33, 95% confidence interval (CI): 1.16-16.07]. Consumption of four or more maintenance doses of HCQ was associated with a significant decline in the odds of getting infected (AOR: 0.44; 95% CI: 0.22-0.88); a dose-response relationship existed between frequency of exposure to HCQ and such reductions (χ[2] for trend=48.88; P <0.001). In addition, the use of PPE was independently associated with the reduction in odds of getting infected with SARS-CoV-2.
Interpretations & conclusions: Until results of clinical trials for HCQ prophylaxis become available, this study provides actionable information for policymakers to protect HCWs at the forefront of COVID-19 response. The public health message of sustained intake of HCQ prophylaxis as well as appropriate PPE use need to be considered in conjunction with risk homoeostasis operating at individual levels.

PMID: 32611916 [PubMed - in process]

National sero-surveillance to monitor the trend of SARS-CoV-2 infection transmission in India: Protocol for community-based surveillance.

July 3, 2020
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National sero-surveillance to monitor the trend of SARS-CoV-2 infection transmission in India: Protocol for community-based surveillance.

Indian J Med Res. 2020 May;151(5):419-423

Authors: Kumar MS, Bhatnagar T, Manickam P, Kumar VS, Rade K, Shah N, Kant S, Babu GR, Zodpey S, Girish Kumar CP, Vivian Thangaraj JW, Chatterjee P, Kanungo S, Pandey RM, Murhekar M, Singh SK, Sarkar S, Muliyi JP, Gangakhedkar RR, Reddy DCS

Abstract
Conducting population-based serosurveillance for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) will estimate and monitor the trend of infection in the adult general population, determine the socio-demographic risk factors and delineate the geographical spread of the infection. For this purpose, a serial cross-sectional survey would be conducted with a sample size of 24,000 distributed equally across four strata of districts categorized on the basis of the incidence of reported cases of COVID-19. Sixty districts will be included in the survey. Simultaneously, the survey will be done in 10 high-burden hotspot cities. ELISA-based antibody tests would be used. Data collection will be done using a mobile-based application. Prevalence from the group of districts in each of the four strata will be pooled to estimate the population prevalence of COVID-19 infection, and similarly for the hotspot cities, after adjusting for demographic characteristics and antibody test performance. The total number of reported cases in the districts and hotspot cities will be adjusted using this seroprevalence to estimate the expected number of infected individuals in the area. Such serosurveys repeated at regular intervals can also guide containment measures in respective areas. State-specific context of disease burden, priorities and resources should guide the use of multifarious surveillance options for the current COVID-19 epidemic.

PMID: 32611913 [PubMed - in process]

Gold-standard cholera diagnostics are tarnished by lytic bacteriophage and antibiotics.

July 3, 2020
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Gold-standard cholera diagnostics are tarnished by lytic bacteriophage and antibiotics.

J Clin Microbiol. 2020 Jul 01;:

Authors: Nelson EJ, Grembi JA, Chao DL, Andrews JR, Alexandrova L, Rodriguez PH, Ramachandran VV, Sayeed MA, Wamala JF, Debes AK, Sack DA, Hryckowian AJ, Haque F, Khatun S, Rahman M, Chien A, Spormann AM, Schoolnik GK

Abstract
A fundamental, clinical and scientific concern is how lytic bacteriophage, as well as antibiotics, impact diagnostic positivity. Cholera was chosen as a model disease to investigate this important question because cholera outbreaks enable large enrollment, field methods are well established, and the predatory relationship between lytic bacteriophage and the etiologic agent Vibrio cholerae share commonalities across bacterial taxa. Patients with diarrheal disease were enrolled at two remote hospitals in Bangladesh. Diagnostic performance was assessed as a function of lytic bacteriophage detection and exposure to the first-line antibiotic azithromycin detected in stool samples by mass spectrometry. Among diarrheal samples positive by nanoliter quantitative PCR for V. cholerae (n=78/849), the odds that a rapid diagnostic test (RDT) or qPCR was positive was reduced by 89% (OR 0.108; 95%CI 0.002-0.872) and 87% (OR 0.130; 95%CI 0.022-0.649) when lytic bacteriophage were detected, respectively. The odds that a rapid diagnostic test (RDT) or qPCR was positive was reduced by more than 99% (OR 0.00; 95% CI: 0.00-0.28) and 89% (OR 0.11; 95% CI: 0.03-0.44) when azithromycin was detected, respectively. Analysis of additional samples from South Sudan found similar phage effects on RDTs; antibiotics were not assayed. Cholera burden estimates may improve by accommodating for the negative effects of lytic bacteriophage and antibiotic exposure on diagnostic positivity. One accommodation is using bacteriophage detection as proxy for pathogen detection. These findings have relevance for other diagnostic settings where bacterial pathogens are vulnerable to lytic bacteriophage predation.

PMID: 32611794 [PubMed - as supplied by publisher]

Genomic analysis of pathogenic isolates of Vibrio cholerae from eastern Democratic Republic of the Congo (2014-2017).

July 2, 2020
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Genomic analysis of pathogenic isolates of Vibrio cholerae from eastern Democratic Republic of the Congo (2014-2017).

PLoS Negl Trop Dis. 2020 04;14(4):e0007642

Authors: Irenge LM, Ambroise J, Mitangala PN, Bearzatto B, Kabangwa RKS, Durant JF, Gala JL

Abstract
BACKGROUND: Over the past recent years, Vibrio cholerae has been associated with outbreaks in sub-Saharan Africa, notably in Democratic Republic of the Congo (DRC). This study aimed to determine the genetic relatedness of isolates responsible for cholera outbreaks in eastern DRC between 2014 and 2017, and their potential spread to bordering countries.
METHODS/PRINCIPAL FINDINGS: Phenotypic analysis and whole genome sequencing (WGS) were carried out on 78 clinical isolates of V. cholerae associated with cholera in eastern provinces of DRC between 2014 and 2017. SNP-based phylogenomic data show that most isolates (73/78) were V. cholerae O1 biotype El Tor with CTX-3 type prophage. They fell within the third transmission wave of the current seventh pandemic El Tor (7PET) lineage and were contained in the introduction event (T)10 in East Africa. These isolates clustered in two sub-clades corresponding to Multiple Locus Sequence Types (MLST) profiles ST69 and the newly assigned ST515, the latter displaying a higher genetic diversity. Both sub-clades showed a distinct geographic clustering, with ST69 isolates mostly restricted to Lake Tanganyika basin and phylogenetically related to V. cholerae isolates associated with cholera outbreaks in western Tanzania, whereas ST515 isolates were disseminated along the Albertine Rift and closely related to isolates in South Sudan, Uganda, Tanzania and Zambia. Other V. cholerae isolates (5/78) were non-O1/non-O139 without any CTX prophage and no phylogenetic relationship with already characterized non-O1/non-O139 isolates.
CONCLUSIONS/SIGNIFICANCE: Current data confirm the association of both DRC O1 7PET (T)10 sub-clades ST69 and ST515 with recurrent outbreaks in eastern DRC and at regional level over the past 10 years. Interestingly, while ST69 is predominantly a locally endemic sequence type, ST515 became adaptable enough to expand across DRC neighboring countries.

PMID: 32310947 [PubMed - indexed for MEDLINE]

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