The cholera outbreak in Yemen: lessons learned and way forward

Flip bifurcation analysis and mathematical modeling of cholera disease by taking control measures

To study the dynamical system, it is necessary to formulate the mathematical model to understand the dynamics of various diseases which are spread in the world wide. The objective of the research study is to assess the early diagnosis and treatment of cholera virus by implementing remedial methods with and without the use of drugs. A mathematical model is built with the hypothesis of strengthening the immune system, and a ABC operator is employed to turn the model into a fractional-order model. A newly developed system SEIBR, which is examined both qualitatively and quantitatively to determine its stable position as well as the verification of flip bifurcation has been made for developed system. The local stability of this model has been explored concerning limited observations, a fundamental aspect of epidemic models. We have derived the reproductive number using next generation method, denoted as " R 0 ", to analyze its impact rate across various sub-compartments, which serves as a critical determinant of its community-wide transmission rate. The sensitivity analysis has been verified according to its each parameters to identify that how much rate of change of parameters are sensitive. Atangana-Toufik scheme is employed to find the solution for the developed system using different fractional values which is advanced tool for reliable bounded solution. Also the error analysis has been made for developed scheme. Simulations have been made to see the real behavior and effects of cholera disease with early detection and treatment by implementing remedial methods without the use of drugs in the community. Also identify the real situation the spread of cholera disease after implementing remedial methods with and without the use of drugs. Such type of investigation will be useful to investigate the spread of virus as well as helpful in developing control strategies from our justified outcomes.

Case-area targeted interventions during a large-scale cholera epidemic: A prospective cohort study in Northeast Nigeria

BACKGROUND

Cholera outbreaks are on the rise globally, with conflict-affected settings particularly at risk. Case-area targeted interventions (CATIs), a strategy whereby teams provide a package of interventions to case and neighboring households within a predefined "ring," are increasingly employed in cholera responses. However, evidence on their ability to attenuate incidence is limited.

METHODS AND FINDINGS

We conducted a prospective observational cohort study in 3 conflict-affected states in Nigeria in 2021. Enumerators within rapid response teams observed CATI implementation during a cholera outbreak and collected data on household demographics; existing water, sanitation, and hygiene (WASH) infrastructure; and CATI interventions. Descriptive statistics showed that CATIs were delivered to 46,864 case and neighbor households, with 80.0% of cases and 33.5% of neighbors receiving all intended supplies and activities, in a context with operational challenges of population density, supply stock outs, and security constraints. We then applied prospective Poisson space-time scan statistics (STSS) across 3 models for each state: (1) an unadjusted model with case and population data; (2) an environmentally adjusted model adjusting for distance to cholera treatment centers and existing WASH infrastructure (improved water source, improved latrine, and handwashing station); and (3) a fully adjusted model adjusting for environmental and CATI variables (supply of Aquatabs and soap, hygiene promotion, bedding and latrine disinfection activities, ring coverage, and response timeliness). We ran the STSS each day of our study period to evaluate the space-time dynamics of the cholera outbreaks. Compared to the unadjusted model, significant cholera clustering was attenuated in the environmentally adjusted model (from 572 to 18 clusters) but there was still risk of cholera transmission. Two states still yielded significant clusters (range 8-10 total clusters, relative risk of 2.2-5.5, 16.6-19.9 day duration, including 11.1-56.8 cholera cases). Cholera clustering was completely attenuated in the fully adjusted model, with no significant anomalous clusters across time and space. Associated measures including quantity, relative risk, significance, likelihood of recurrence, size, and duration of clusters reinforced the results. Key limitations include selection bias, remote data monitoring, and the lack of a control group.

CONCLUSIONS

CATIs were associated with significant reductions in cholera clustering in Northeast Nigeria despite operational challenges. Our results provide a strong justification for rapid implementation and scale-up CATIs in cholera-response, particularly in conflict settings where WASH access is often limited.

The Governance of Childhood Vaccination Services in Crisis Settings: A Scoping Review

The persistence of inadequate vaccination in crisis-affected settings raises concerns about decision making regarding vaccine selection, timing, location, and recipients. This review aims to describe the key features of childhood vaccination intervention design and planning in crisis-affected settings and investigate how the governance of childhood vaccination is defined, understood, and practised. We performed a scoping review of 193 peer-reviewed articles and grey literature on vaccination governance and service design and planning. We focused on 41 crises between 2010 and 2021. Following screening and data extraction, our analysis involved descriptive statistics and applying the governance analysis framework to code text excerpts, employing deductive and inductive approaches. Most documents related to active outbreaks in conflict-affected settings and to the mass delivery of polio, cholera, and measles vaccines. Information on vaccination modalities, target populations, vaccine sources, and funding was limited. We found various interpretations of governance, often implying hierarchical authority and regulation. Analysis of governance arrangements suggests a multi-actor yet fragmented governance structure, with inequitable actor participation, ineffective actor collaboration, and a lack of a shared strategic vision due to competing priorities and accountabilities. Better documentation of vaccination efforts during emergencies, including vaccination decision making, governance, and planning, is needed. We recommend empirical research within decision-making spaces.

Association between air raids and reported incidence of cholera in Yemen, 2016-19: an ecological modelling study

BACKGROUND

Yemen continues to endure cholera outbreaks during ongoing conflict and destructive environmental events. Air raids have been used throughout the conflict to target military and civilian infrastructure. We aimed to assess the association between air raids and cholera incidence while taking into account geographical, environmental, economic, and demographic factors that drive outbreaks.

METHODS

In this ecological modelling study, we used data from Sept 12, 2016, to Dec 29, 2019, for the number of air raids, vegetation coverage, surface water, precipitation, temperature, economic variables, and cholera case and population data to model the association between conflict and the weekly incidence of cholera (per 100 000 people) in Yemen. Data were transformed into weekly intervals and governorates were categorised according to air raid severity (the number of raids in the previous 3 months). We used a negative binomial generalised additive model that accounted for geographical location and environmental, temporal, economic, and demographic variables to estimate incidence rate ratios for the association between air raid severity and cases of cholera.

FINDINGS

During the study period, 2 107 912 cases of cholera were reported in Yemen, and a minimum of 11 366 air raids were recorded. After controlling for relevant factors, compared with no air raids, all other levels of air raid severity were significantly associated with cholera incidence. The largest effect was noted in governorates with severe air raid levels (ie, ≥76 during the previous 3 months), which had an incidence rate ratio of 2·06 (95% CI 1·59-2·69; p<0·0001) for cholera compared with governorates with no air raids in the previous 3 months. Economic factors were also significantly associated with increased cholera incidence.

INTERPRETATION

Air raids were significantly associated with the burden of cholera in Yemen, even after controlling for other relevant factors. Quantification of this relationship further shows that the cholera outbreak is largely a result of human action rather than a natural occurrence, and demonstrates the conflict's devastating effects on health. Our findings highlight the need for ceasefire and peacebuilding efforts, as well as infrastructure and economic restoration, to reduce Yemen's cholera burden.

FUNDING

None.

TRANSLATION

For the Arabic translation of the abstract see Supplementary Materials section.

Cholera: An Overview with Reference to the Syrian Outbreak

Cholera is an acute type of diarrheal disease caused by intestinal infection with the toxin-producing bacteria Vibrio cholerae. The disease is still endemic in almost 69 countries, accounting for around 2.86 million cases and 95,000 deaths annually. Cholera is associated with poor infrastructure, and lack of access to sanitation and clean drinking water. The current cholera outbreak in Syria is associated with more than 10 years of conflict, which has devastated infrastructures and health services. There were 132,782 suspected cases reported between August 25, 2022 and May 20, 2023 in all 14 governorates, including 104 associated deaths. The recent earthquake in the region has complicated the situation, with an increase in cholera cases, and hindrance to a response to the disease. Climate change has driven a number of large cholera outbreaks around the world this year. The World Health Organization prequalifies three oral cholera vaccines. Cholera treatment mainly depends on rehydration, with the use of antibiotics in more severe infections. This review gives an overview of cholera bacteriology, pathogenesis, epidemiology, clinical manifestations, diagnosis, management, and prevention in light of global climate change and the ongoing outbreak in Syria, which poses a significant public health threat that requires urgent attention.

Geographical Origin, WASH Access, and Clinical Descriptions for Patients Admitted to a Cholera Treatment Center in Northwest Syria between October and December 2022

Background  On September 10, 2022, a cholera outbreak was declared in Syria for the first time in over a decade of protracted conflict. As of May 20, 2023, 132,782 suspected cases had been reported, primarily in northwest and northeast Syria. We aim to provide a detailed description of water sources and clinical status of a patient cohort seen at a cholera treatment center (CTC) in northwest Syria. Methods  We retrospectively identified patients with confirmed cholera who presented to the CTC in Idlib governorate between October 8 and December 18, 2022. Data were obtained from clinical case records and analyzed in R v4.0.4. Results  Ninety-four patients (55.3% men) were treated at the CTC. Thirty-five patients were severely dehydrated (Plan C treatment), 54 had some dehydration (Plan B), and 5 had no dehydration (Plan A). Most patients were between 11 and 20 years old ( n  = 25, 26.6%) or 31 and 40 years old ( n  = 19, 20.2%). Note that 70.2% ( n  = 66) of patients were seen in November 2022 and most were from Harim district ( n  = 44, 46.8%). Public wells ( n  = 46, 48.9%) and water trucking ( n  = 41, 43.6%) were the most commonly used water sources. Note that 76.6% ( n  = 72) did not have access to chlorine-treated water. Forty-seven patients (50%) had more than five water, sanitation, and hygiene (WASH)-related cholera risk factors. Following treatment, six patients were transferred to another treatment center, three died (case fatality rate: 3.2%), and the remainder were discharged. Conclusion  Most patients reported WASH-related risk factors for cholera, reflecting the poor state of WASH in northwest Syria after over a decade of conflict. This relates to the direct and indirect impacts of urban and periurban violence as well as the underfunded humanitarian response. Strengthening WASH and health promotion are important components to control the outbreak.

Genomic epidemiology reveals multidrug resistant plasmid spread between Vibrio cholerae lineages in Yemen

Since 2016, Yemen has been experiencing the largest cholera outbreak in modern history. Multidrug resistance (MDR) emerged among Vibrio cholerae isolates from cholera patients in 2018. Here, to characterize circulating genotypes, we analysed 260 isolates sampled in Yemen between 2018 and 2019. Eighty-four percent of V. cholerae isolates were serogroup O1 belonging to the seventh pandemic El Tor (7PET) lineage, sub-lineage T13, whereas 16% were non-toxigenic, from divergent non-7PET lineages. Treatment of severe cholera with macrolides between 2016 and 2019 coincided with the emergence and dominance of T13 subclones carrying an incompatibility type C (IncC) plasmid harbouring an MDR pseudo-compound transposon. MDR plasmid detection also in endemic non-7PET V. cholerae lineages suggested genetic exchange with 7PET epidemic strains. Stable co-occurrence of the IncC plasmid with the SXT family of integrative and conjugative element in the 7PET background has major implications for cholera control, highlighting the importance of genomic epidemiological surveillance to limit MDR spread.

The cholera outbreak in Syria: a call for urgent actions

The ongoing cholera outbreak in Syria poses a significant public health threat that requires immediate and comprehensive attention. The spread of the outbreak is attributed to a combination of factors, including displacement due to armed conflict, chronic water insecurity, inadequate water, sanitation, and hygiene infrastructure, climate change-induced droughts, weakened health system capacity, and political instability. The recent earthquake in the region has further complicated the situation, potentially leading to a surge in cholera cases. The limited capacity of the Syrian health system to handle the cholera outbreak, especially after the earthquake, highlights the urgent need for external support. The political instability in the country has hampered effective responses to the outbreak, contributing to the spread of the disease beyond Syria's borders. It is imperative to prioritize aid to address the fragmented response and provide the necessary resources for comprehensive and effective cholera prevention and control measures. The situation calls for an integrated, multi-sectoral approach that prioritizes economic development, universal access to sustainable safe drinking water, and adequate sanitation. Additionally, community engagement and education are essential for effective disease prevention and control. In conclusion, the ongoing cholera outbreak in Syria is a complex issue that requires urgent attention and action. The combination of armed conflict, water insecurity, climate change, and political instability have contributed to the spread of the disease, further compounded by the recent earthquake. To effectively address the outbreak and prevent its further spread, a comprehensive and integrated approach is needed, with support from the international community.

Changing Water-Sanitation Determinants of Cholera over Two Decades in Bangladesh

Cholera is a leading global public health threat, especially in developing countries. This study aimed to determine the changing determinants of cholera related to water-sanitation practices between 1994-1998 and 2014-2018 in Dhaka, Bangladesh. Data of all cause diarrhea cases were extracted from the Diarrheal Disease Surveillance System of the International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, and analysis was performed among three groups: Vibrio cholerae detected as sole pathogen, V. cholerae detected as mixed infection, and detection of no common enteropathogen in stool specimens (reference). Using sanitary toilet, drinking tap water, drinking boiled water, family size greater than five, and slum dwelling were the main exposures. Overall, 3,380 (20.30%) and 1,290 (9.69%) patients were positive for V. cholerae during 1994-1998 and 2014-2018, respectively. In 1994-1998, use of sanitary toilet (adjusted odds ratio [aOR]: 0.86, 95% CI: 0.76-0.97) and drinking tap water (aOR: 0.81, 95% CI: 0.72-0.92) were found to be negatively associated and in 2014-2018, drinking tap water (aOR: 1.47, 95% CI: 1.21-1.78) and slum dwelling (aOR: 1.43, 95% CI: 1.10-1.86) were found to be positively associated with V. cholerae infection after adjusting for age, sex, monthly income, and seasonality. Because the determinants of cholera such as drinking tap water can change over time in developing cities, ameliorating the water, sanitation, and hygiene (WASH) situation is of paramount importance. In addition, in settings such as urban slums, where long-term WASH monitoring might be difficult to achieve, mass vaccination with oral cholera vaccine should be introduced to control cholera.

Genomic epidemiology of Vibrio cholerae during a mass vaccination campaign of displaced communities in Bangladesh

Ongoing diarrheal disease surveillance throughout Bangladesh over the last decade has revealed seasonal localised cholera outbreaks in Cox's Bazar, where both Bangladeshi Nationals and Forcibly Displaced Myanmar Nationals (FDMNs) reside in densely populated settlements. FDMNs were recently targeted for the largest cholera vaccination campaign in decades. We aimed to infer the epidemic risk of circulating Vibrio cholerae strains by determining if isolates linked to the ongoing global cholera pandemic ("7PET" lineage) were responsible for outbreaks in Cox's Bazar. We found two sublineages of 7PET in this setting during the study period; one with global distribution, and a second lineage restricted to Asia and the Middle East. These subclades were associated with different disease patterns that could be partially explained by genomic differences. Here we show that as the pandemic V. cholerae lineage circulates in this vulnerable population, without a vaccine intervention, the risk of an epidemic was very high.

Cholera prevention, control strategies, challenges and World Health Organization initiatives in the Eastern Mediterranean Region: A narrative review

The resurgence of cholera is presenting unusual challenges in the Eastern Mediterranean Region (EMR), where it is considered endemic in nine-member states. The risk of a cholera outbreak spreading to non-endemic countries remains high. We discuss the regional trends of cholera, regional burden, and challenges with a focus on World Health Organization (WHO) initiatives in the region that could be useful in preventing and controlling the disease in similar contexts. Despite significant progress in the control of cholera worldwide, the disease continues to be a major public health problem across the region, where it constitutes both an emerging and re-emerging threat. Recurring cholera outbreaks are an indication of deprived water and sanitation conditions as well as weak health systems, contributing to the transmission and spread of the cholera infection. We note that despite the challenges in eliminating cholera in the region, effective implementation of the proposed WHO EMR Strategic framework, among other measures, could sustain the region's cholera prevention, preparedness, and response needs.

Healthcare workers knowledge of cholera multi-stranded interventions and its determining factors in North-East Nigeria: planning and policy implications

BACKGROUND

Healthcare workers' (HCWs) knowledge of multi-stranded cholera interventions (including case management, water, sanitation, and hygiene (WASH), surveillance/laboratory methods, coordination, and vaccination) is crucial to the implementation of these interventions in healthcare facilities, especially in conflict-affected settings where cholera burden is particularly high. We aimed to assess Nigerian HCWs' knowledge of cholera interventions and identify the associated factors.

METHODS

We conducted a cross-sectional study using a structured interviewer-administered questionnaire with HCWs from 120 healthcare facilities in Adamawa and Bauchi States, North-East Nigeria. A knowledge score was created by assigning a point for each correct response. HCWs' knowledge of cholera interventions, calculated as a score, was recoded for ease of interpretation as follows: 0-50 (low); 51-70 (moderate); ≥ 71 (high). Additionally, we defined the inadequacy of HCWs' knowledge of cholera interventions based on a policy-relevant threshold of equal or lesser than 75 scores for an intervention. Multivariable logistic regression was used to identify the factors associated with the adequacy of knowledge score.

RESULTS

Overall, 490 HCWs participated in the study (254 in Adamawa and 236 in Bauchi), with a mean age of 35.5 years. HCWs' knowledge score was high for surveillance/laboratory methods, moderate for case management, WASH, and vaccination, and low for coordination. HCWs' knowledge of coordination improved with higher cadre, working in urban- or peri-urban-based healthcare facilities, and secondary education; cholera case management and vaccination knowledge improved with post-secondary education, working in Bauchi State and urban areas, previous training in cholera case management and response to a cholera outbreak-working in peri-urban areas had a negative effect. HCWs' knowledge of surveillance/laboratory methods improved with a higher cadre, 1-year duration in current position, secondary or post-secondary education, previous training in cholera case management and response to a cholera outbreak. However, HCWs' current position had both positive and negative impacts on their WASH knowledge.

CONCLUSIONS

HCWs in both study locations recorded a considerable knowledge of multi-stranded cholera interventions. While HCWs' demographic characteristics appeared irrelevant in determining their knowledge of cholera interventions, geographic location and experiences from the current position, training and involvement in cholera outbreak response played a significant role.

Knowledge, Attitudes and Practices on Cholera and Water, Sanitation, and Hygiene among Internally Displaced Persons in Cabo Delgado Province, Mozambique

In disaster situations, cholera outbreaks represent a public health emergency due to their high fatality rates and high spreading risk through camps for refugees and internally displaced persons (IDPs). The aim of this study is to examine water, sanitation, and hygiene attitudes and cholera knowledge, attitude, and practice (KAP) among people living in resettlement sites in Cabo Delgado, the northernmost province of Mozambique. Between January 1 and March 31, 2022, a cross-sectional survey was conducted by administering a face-to-face interview to IDPs and residents in six relocation sites in Cabo Delgado Province. A total of 440 people were enrolled in the study. Overall, 77.8% (N = 342) were female, 61% (N = 268) were younger than 35 years old, and 60.5% (N = 266) reported primary school to be the highest education level. Seventy-five percent (N = 334) of participants lived with children under 5 years old. Thirty-one percent (N = 140) and 11.8% (N = 52) of the respondents reported, respectively, at least one cholera case and at least one diarrheal-related death among their family members in the previous 2 years. In multivariate analysis, being female, being younger than 35 years old, having attained a higher education level, owning a phone, or having soap at home were factors significantly associated with improved cholera KAP. In severely deconstructed social contexts, continuous education and community sensitization are crucial to achieve and maintain positive cholera prevention attitudes.

Knowledge, Attitude, and Practice in a Sample of the Lebanese Population Regarding Cholera

The evaluation of knowledge, attitude, and practices towards an emerging disease is an essential component of public health preventive measures during an outbreak. In October 2022, an outbreak of cholera was reported in Lebanon, which is the first to be reported in the Middle Eastern country for 30 years. This study aimed to explore the level of knowledge as well as attitude and practice of the general public in Lebanon towards cholera. A self-administered structured questionnaire was distributed via an online link to individuals living in Lebanon during October-November 2022. The survey instrument comprised items to assess the sociodemographic data; questions on knowledge about cholera symptoms, transmission, and prevention; as well as attitude and practice questions. Our study involved 553 participants, with a median age of 24 years and a majority of females (72.5%). The results showed that the majority of respondents correctly identified diarrhea as a symptom of cholera and recognized the spread via contaminated water and food. Having a university level education compared with secondary school or less (adjusted odds ratio (aOR) = 2.09), being married compared with single (aOR = 1.67), and working in the medical field compared with unemployed (aOR = 4.19) were significantly associated with higher odds of having good cholera knowledge. Having good knowledge compared with having a poor level of cholera knowledge (aOR = 1.83) and older age (aOR = 1.03) were significantly associated with higher odds of having a good attitude towards cholera. The current study showed an overall high knowledge score on cholera among the Lebanese population. Nevertheless, gaps in cholera knowledge were identified and should be addressed, particularly among workers in the medical field. Thus, we recommend targeted health education to the general population that aims to strengthen the health resilience in the community.

Skin disease and military conflicts: Lessons from the Crimean War (1854-56)

In the Crimean War (1854-56), infamous for its high death rate from disease at 212 per thousand British troops annually - one third of which was due to cholera or dysentery - skin disease was common, accounting for 13% of all admissions and 4.2% of all deaths. Excluding typhus, skin disease caused 252 per thousand annual admissions and 8.8 per thousand annual deaths, with an overall case fatality of 3.4%. The commonest skin diseases were: localised cellulitis/abscess, ulcer, venereal disease, frostbite, scurvy, eruptive rashes and scabies. The biggest number of skin disease-related deaths were from frostbite and scurvy. Cutaneous afflictions with the highest case fatality were erysipelas (27%), gangrene (25%), smallpox (21%) and frostbite (19%). Problems from frostbite lessened during the better provisioned second winter. The experience of skin disease in the Crimea highlights the importance of public health and personal sanitation to skin health in the military context, and shows that skin-related infections and nutritional deficiencies easily develop if environmental conditions deteriorate.

Mucosal and systemic immune responses to Vibrio cholerae infection and oral cholera vaccines (OCVs) in humans: a systematic review

INTRODUCTION

Cholera is an enteric disease caused by Vibrio cholerae, a water-borne pathogen, and characterized by severe diarrhea. Vaccines have been recommended for use by the WHO in resource-limited settings. Efficacies of the currently licensed cholera vaccines are not optimal in endemic settings and low in children below the age of five, a section of the population most susceptible to the disease. Development of next generation of cholera vaccines would require a detailed understanding of the required protective immune responses.

AREA COVERED

In this review, we revisit clinical trials which are focused on the early transcriptional mucosal responses elicited during Vibrio cholerae infection and upon vaccination along with summarizing various components of the effector immune response against Vibrio cholerae.

EXPERT OPINION

The inability of currently licensed killed/inactivated vaccines to elicit key inflammatory pathways locally may explain their restricted efficacy in endemic settings. More studies are required to understand the immunogenicity of the live attenuated cholera vaccine in these regions. Various extrinsic and intrinsic factors influence anti-cholera immunity and need to be considered to develop region-specific next generation vaccines.

Fielding vaccines-challenges and opportunities in outbreaks, complex emergencies, and mass gatherings

With the recent COVID-19 pandemic, the importance of vaccine development, distribution, and uptake has come to the forefront of the public eye. Effectively fielding vaccines during an emergency-whether that emergency is a result of an infectious disease or not-requires an understanding of usual vaccine-related processes; the impact of outbreak, complex emergencies, mass gatherings, and other events on patients, communities, and health systems; and ways in which diverse resources can be applied to successfully achieve needed vaccine uptake. In this review, both the emergency setting and briefly vaccine product design are discussed in these contexts in order to provide a concise source of general knowledge from experts in fielding vaccines that can aid in future vaccine ventures and increase general awareness of the process and barriers in various settings.

Mathematical Models for Cholera Dynamics-A Review

Cholera remains a significant public health burden in many countries and regions of the world, highlighting the need for a deeper understanding of the mechanisms associated with its transmission, spread, and control. Mathematical modeling offers a valuable research tool to investigate cholera dynamics and explore effective intervention strategies. In this article, we provide a review of the current state in the modeling studies of cholera. Starting from an introduction of basic cholera transmission models and their applications, we survey model extensions in several directions that include spatial and temporal heterogeneities, effects of disease control, impacts of human behavior, and multi-scale infection dynamics. We discuss some challenges and opportunities for future modeling efforts on cholera dynamics, and emphasize the importance of collaborations between different modeling groups and different disciplines in advancing this research area.

Conflict-related environmental damages on health: lessons learned from the past wars and ongoing Russian invasion of Ukraine

On 24 February 2022, Russian military forces invaded Ukraine. The fighting has already caused unimaginable conditions and millions of people were forced to flee their homes. For decades, conflicts have been linked to environmental pollution, exposure to radioactivity and heavy metals as well as infectious diseases. The invasion may cause specific environmental risks, like the release of radioactive substances from nuclear power plants and contaminated soils. Because international collaboration is one of the most effective ways to address environmental problems, it is critical to establish scientific bodies within a global framework to identify concrete actions and tangible measures to provide immediate assistance to citizens. This commentary discusses the above issues from lessons learned from the past wars and the way forward in the Russian invasion of Ukraine.

Water, Sanitation, and Hygiene (WASH) Practices and Outreach Services in Settlements for Rohingya Population in Cox's Bazar, Bangladesh, 2018-2021

(1) Background: This study aimed to investigate the existing water, sanitation, and hygiene (WASH) policy and practice of the study population and strengthen the evidence base by documenting changes in the WASH policy and practice over 3 years of the Rohingya refugee humanitarian crisis, Cox's Bazar, Bangladesh. (2) Methods: A cross-sectional surveillance design was followed; the sampling of the study population included the Rohingya refugee population and neighborhood host nationals who required hospitalization soon after seeking care and enrolled into the diarrheal disease surveillance in diarrhea-treatment centers. Throughout the study period of 3 years, a total of 4550 hospitalized individuals constituted the study participants. (3) Results: Among the hospitalized Rohingya refugee population; the use of public tap water increased significantly from 38.5% in year 1 to 91% in year 3. The use of deep tube well water significantly changed from 31.3% to 8.2%, and the use of shallow tube well water reduced significantly from 25.8% to 0.4%. Households using water seal latrine were 13.3% in year 1 and increased significantly to 31.7% in year 3. ORS consumption at home changed significantly from 61.5% in the first year to 82.1% in third year. Multivariable analysis demonstrated patients' age groups at 5 to 14 years, and 15 years and more, drinking non-tube well water, soap use after using toilet, use of non-sanitary toilet facility, father's and mother's lack of schooling, and some and severe dehydration were significantly associated with the Rohingya refugee population enrolled into the diarrheal disease surveillance. (4) Conclusion: The findings indicate significant advances in WASH service delivery as well as outreach activities by aid agencies for the Rohingya refugee population living in settlements.

Emerging and Re-emerging Infectious Diseases in the WHO Eastern Mediterranean Region, 2001-2018

BACKGROUND

Countries in the World Health Organization (WHO) Eastern Mediterranean Region (EMR) are predisposed to highly contagious, severe and fatal, emerging infectious diseases (EIDs), and re-emerging infectious diseases (RIDs). This paper reviews the epidemiological situation of EIDs and RIDs of global concern in the EMR between 2001 and 2018.

METHODS

To do a narrative review, a complete list of studies in the field was we prepared following a systematic search approach. Studies that were purposively reviewed were identified to summarize the epidemiological situation of each targeted disease. A comprehensive search of all published studies on EIDs and RIDs between 2001 and 2018 was carried out through search engines including Medline, Web of Science, Scopus, Google Scholar, and ScienceDirect.

RESULTS

Leishmaniasis, hepatitis A virus (HAV) and hepatitis E virus (HEV) are reported from all countries in the region. Chikungunya, Crimean Congo hemorrhagic fever (CCHF), dengue fever, and H5N1 have been increasing in number, frequency, and expanding in their geographic distribution. Middle East respiratory syndrome (MERS), which was reported in this region in 2012 is still a public health concern. There are challenges to control cholera, diphtheria, leishmaniasis, measles, and poliomyelitis in some of the countries. Moreover, Alkhurma hemorrhagic fever (AHF), and Rift Valley fever (RVF) are limited to some countries in the region. Also, there is little information about the real situation of the plague, Q fever, and tularemia.

CONCLUSION

EIDs and RIDs are prevalent in most countries in the region and could further spread within the region. It is crucial to improve regional capacities and capabilities in preventing and responding to disease outbreaks with adequate resources and expertise.

Cholera diagnosis in human stool and detection in water: A systematic review and meta-analysis

Background

Cholera continues to pose a problem for low-resource, fragile and humanitarian contexts. Evidence suggests that 2.86 million cholera cases and 95,000 deaths due to cholera are reported annually. Without quick and effective diagnosis and treatment, case-fatality may be 50%. In line with the priorities of the Global Task Force on Cholera Control, we undertook a systematic review and meta-analysis of diagnostic test accuracy and other test characteristics of current tests for cholera detection in stool and water.

Methods

We searched 11 bibliographic and grey literature databases. Data was extracted on test sensitivity, specificity and other product information. Meta-analyses of sensitivity and specificity were conducted for tests reported in three or more studies. Where fewer studies reported a test, estimates were summarised through narrative synthesis. Risk of Bias was assessed using QUADAS-2.

Results

Searches identified 6,637 records; 41 studies reporting on 28 tests were included. Twenty-two tests had both sensitivities and specificities reported above 95% by at least one study, but there was, overall, wide variation in reported diagnostic accuracy across studies. For the three tests where meta-analyses were possible the highest sensitivity meta-estimate was found in the Cholera Screen test (98.6%, CI: 94.7%-99.7%) and the highest specificity meta-estimate in the Crystal VC on enriched samples (98.3%, CI: 92.8%-99.6%). There was a general lack of evidence regarding field use of tests, but where presented this indicated trends for lower diagnostic accuracy in field settings, with lesser-trained staff, and without the additional process of sample enrichment. Where reported, mean test turnaround times ranged from over 50% to 130% longer than manufacturer’s specification. Most studies had a low to unclear risk of bias.

Conclusions

Currently available Rapid Diagnostic Tests can potentially provide high diagnostic and detection capability for cholera. However, stronger evidence is required regarding the conditions required to secure these levels of accuracy in field use, particularly in low-resource settings.

Registration

PROSPERO (CRD42016048428).

Dynamic mapping of cholera outbreak during the Yemeni Civil War, 2016-2019

Widespread destruction from the Yemeni Civil War (2014-present) triggered the world's largest cholera outbreak. We compiled a comprehensive health dataset and created dynamic maps to demonstrate spatiotemporal changes in cholera infections and war conflicts. We aligned and merged daily, weekly, and monthly epidemiological bulletins of confirmed cholera infections and daily conflict events and fatality records to create a dataset of weekly time series for Yemen at the governorate level (subnational regions administered by governors) from 4 January 2016 through 29 December 2019. We demonstrated the use of dynamic mapping for tracing the onset and spread of infection and manmade factors that amplify the outbreak. We report curated data and visualization techniques to further uncover associations between infectious disease outbreaks and risk factors and to better coordinate humanitarian aid and relief efforts during complex emergencies.

Gold nanoparticle-based optical nanosensors for food and health safety monitoring: recent advances and future perspectives

Modern society has been facing serious health-related problems including food safety, diseases and illness. Hence, it is urgent to develop analysis methods for the detection and control of food contaminants, disease biomarkers and pathogens. As the traditional instrumental methods have several disadvantages, including being time consuming, and having high cost and laborious procedures, optical nanosensors have emerged as promising alternative or complementary approaches to those traditional ones. With the advantages of simple preparation, high surface-to-volume ratio, excellent biocompatibility, and especially, unique optical properties, gold nanoparticles (AuNPs) have been demonstrated as excellent transducers for optical sensing systems. Herein, we provide an overview of the synthesis of AuNPs and their excellent optical properties that are ideal for the development of optical nanosensors based on local surface plasmon resonance (LSPR), colorimetry, fluorescence resonance energy transfer (FRET), and surface-enhanced Raman scattering (SERS) phenomena. We also review the sensing strategies and their mechanisms, as well as summarizing the recent advances in the monitoring of food contaminants, disease biomarkers and pathogens using developed AuNP-based optical nanosensors in the past seven years (2015-now). Furthermore, trends and challenges in the application of these nanosensors in the determination of those analytes are discussed to suggest possible directions for future developments.

The utilisation of vaccines in humanitarian crises, 2015-2019: A review of practice

BACKGROUND

The risk factors that emerge with the onset and protraction of humanitarian crises leave populations at a heightened risk of excess morbidity and mortality from vaccine-preventable diseases (VPDs). There is currently little clarity on which vaccines are being used in crises throughout the world, and whether vaccination decisions correspond to local disease threats. This review aimed to collect and analyse such information.

METHODS

We reviewed vaccination services from January 2015 to June 2019 across all 25 humanitarian responses that had an activated coordination mechanism during this period. A range of online sources and informants within the humanitarian sector were consulted to compile data on which vaccines were provided in each crisis, and the modality and timing of vaccine provision. The package of vaccination services since the start of each crisis was then compared with local disease burden (baseline + excess due to crisis-emergent risk factors).

RESULTS

The range of vaccines used in humanitarian crises appears limited. When offered, vaccines were primarily delivered through the pre-existing routine schedule, with few supplementary actions taken in recognition of the need for rapidly enhancing population immunity. Vaccine packages mostly did not address the actual range of VPDs that likely accounted for substantial disease risk.

CONCLUSIONS

This review suggests inconsistencies and inequities in vaccine provision to crisis-affected populations. A consistent, standardised and broader approach to vaccine use in crises is needed.

Learning from the Past: Pandemics and the Governance Treadmill

Global human health threats, such as the ongoing COVID-19 pandemic, necessitate coordinated responses at multiple levels. Public health professionals and other experts broadly agree about actions needed to address such threats, but implementation of this advice is stymied by systemic factors such as prejudice, resource deficits, and high inequality. In these cases, crises like epidemics may be viewed as opportunities to spark structural changes that will improve future prevention efforts. However, crises can also weaken governance and reinforce systemic failures. In this paper, we use the concept of the governance treadmill to demonstrate cross-level dynamics that help or hinder the alignment of capacities toward prevention during public health crises. We find that variation in capacities and responses across local, national, and international levels contributes to the complex evolution of global and local health governance. Where capacities are misaligned, effective local prevention of global pandemic impacts tends to be elusive in the short term, and multiple cycles of crisis and response may be required before capacities align toward healthy governance. We demonstrate that this transition requires broader societal adaptation, particularly towards social justice and participatory democracy.

Modalities and preferred routes of geographic spread of cholera from endemic areas in eastern Democratic Republic of the Congo

Cholera is endemic along the Great Lakes Region, in eastern Democratic Republic of the Congo (DRC). From these endemic areas, also under perpetual conflicts, outbreaks spread to other areas. However, the main routes of propagation remain unclear. This research aimed to explore the modalities and likely main routes of geographic spread of cholera from endemic areas in eastern DRC. We used historical reconstruction of major outbreak expansions of cholera since its introduction in eastern DRC, maps of distribution and spatiotemporal cluster detection analyses of cholera data from passive surveillance (2000–2017) to describe the spread dynamics of cholera from eastern DRC. Four modalities of geographic spread and their likely main routes from the source areas of epidemics to other areas were identified: in endemic eastern provinces, and in non-endemic provinces of eastern, central and western DRC. Using non-parametric statistics, we found that the higher the number of conflict events reported in eastern DRC, the greater the geographic spread of cholera across the country. The present study revealed that the dynamics of the spread of cholera follow a fairly well-defined spatial logic and can therefore be predicted.

The impact of social and environmental extremes on cholera time varying reproduction number in Nigeria

Nigeria currently reports the second highest number of cholera cases in Africa, with numerous socioeconomic and environmental risk factors. Less investigated are the role of extreme events, despite recent work showing their potential importance. To address this gap, we used a machine learning approach to understand the risks and thresholds for cholera outbreaks and extreme events, taking into consideration pre-existing vulnerabilities. We estimated time varying reproductive number (R) from cholera incidence in Nigeria and used a machine learning approach to evaluate its association with extreme events (conflict, flood, drought) and pre-existing vulnerabilities (poverty, sanitation, healthcare). We then created a traffic-light system for cholera outbreak risk, using three hypothetical traffic-light scenarios (Red, Amber and Green) and used this to predict R. The system highlighted potential extreme events and socioeconomic thresholds for outbreaks to occur. We found that reducing poverty and increasing access to sanitation lessened vulnerability to increased cholera risk caused by extreme events (monthly conflicts and the Palmers Drought Severity Index). The main limitation is the underreporting of cholera globally and the potential number of cholera cases missed in the data used here. Increasing access to sanitation and decreasing poverty reduced the impact of extreme events in terms of cholera outbreak risk. The results here therefore add further evidence of the need for sustainable development for disaster prevention and mitigation and to improve health and quality of life.

Signatures of Cholera Outbreak during the Yemeni Civil War, 2016-2019

The Global Task Force on Cholera Control (GTFCC) created a strategy for early outbreak detection, hotspot identification, and resource mobilization coordination in response to the Yemeni cholera epidemic. This strategy requires a systematic approach for defining and classifying outbreak signatures, or the profile of an epidemic curve and its features. We used publicly available data to quantify outbreak features of the ongoing cholera epidemic in Yemen and clustered governorates using an adaptive time series methodology. We characterized outbreak signatures and identified clusters using a weekly time series of cholera rates in 20 Yemeni governorates and nationally from 4 September 2016 through 29 December 2019 as reported by the World Health Organization (WHO). We quantified critical points and periods using Kolmogorov–Zurbenko adaptive filter methodology. We assigned governorates into six clusters sharing similar outbreak signatures, according to similarities in critical points, critical periods, and the magnitude of peak rates. We identified four national outbreak waves beginning on 12 September 2016, 6 March 2017, 28 May 2018, and 28 January 2019. Among six identified clusters, we classified a core regional hotspot in Sana’a, Sana’a City, and Al-Hudaydah—the expected origin of the national outbreak. The five additional clusters differed in Wave 2 and Wave 3 peak frequency, timing, magnitude, and geographic location. As of 29 December 2019, no governorates had returned to pre-Wave 1 levels. The detected similarity in outbreak signatures suggests potentially shared environmental and human-made drivers of infection; the heterogeneity in outbreak signatures implies the potential traveling waves outwards from the core regional hotspot that could be governed by factors that deserve further investigation.

Environmental parameters associated with incidence and transmission of pathogenic Vibrio spp

Vibrio spp. thrive in warm water and moderate salinity, and they are associated with aquatic invertebrates, notably crustaceans and zooplankton. At least 12 Vibrio spp. are known to cause infection in humans, and Vibrio cholerae is well documented as the etiological agent of pandemic cholera. Pathogenic non-cholera Vibrio spp., e.g., Vibrio parahaemolyticus and Vibrio vulnificus, cause gastroenteritis, septicemia, and other extra-intestinal infections. Incidence of vibriosis is rising globally, with evidence that anthropogenic factors, primarily emissions of carbon dioxide associated with atmospheric warming and more frequent and intense heatwaves, significantly influence environmental parameters, e.g., temperature, salinity, and nutrients, all of which can enhance growth of Vibrio spp. in aquatic ecosystems. It is not possible to eliminate Vibrio spp., as they are autochthonous to the aquatic environment and many play a critical role in carbon and nitrogen cycling. Risk prediction models provide an early warning that is essential for safeguarding public health. This is especially important for regions of the world vulnerable to infrastructure instability, including lack of 'water, sanitation, and hygiene' (WASH), and a less resilient infrastructure that is vulnerable to natural calamity, e.g., hurricanes, floods, and earthquakes, and/or social disruption and civil unrest, arising from war, coups, political crisis, and economic recession. Incorporating environmental, social, and behavioural parameters into such models allows improved prediction, particularly of cholera epidemics. We have reported that damage to WASH infrastructure, coupled with elevated air temperatures and followed by above average rainfall, promotes exposure of a population to contaminated water and increases the risk of an outbreak of cholera. Interestingly, global predictive risk models successful for cholera have the potential, with modification, to predict diseases caused by other clinically relevant Vibrio spp. In the research reported here, the focus was on environmental parameters associated with incidence and distribution of clinically relevant Vibrio spp. and their role in disease transmission. In addition, molecular methods designed for detection and enumeration proved useful for predictive modelling and are described, namely in the context of prediction of environmental conditions favourable to Vibrio spp., hence human health risk.

A Review of the Environmental Trigger and Transmission Components for Prediction of Cholera

Climate variables influence the occurrence, growth, and distribution of Vibrio cholerae in the aquatic environment. Together with socio-economic factors, these variables affect the incidence and intensity of cholera outbreaks. The current pandemic of cholera began in the 1960s, and millions of cholera cases are reported each year globally. Hence, cholera remains a significant health challenge, notably where human vulnerability intersects with changes in hydrological and environmental processes. Cholera outbreaks may be epidemic or endemic, the mode of which is governed by trigger and transmission components that control the outbreak and spread of the disease, respectively. Traditional cholera risk assessment models, namely compartmental susceptible-exposed-infected-recovered (SEIR) type models, have been used to determine the predictive spread of cholera through the fecal–oral route in human populations. However, these models often fail to capture modes of infection via indirect routes, such as pathogen movement in the environment and heterogeneities relevant to disease transmission. Conversely, other models that rely solely on variability of selected environmental factors (i.e., examine only triggers) have accomplished real-time outbreak prediction but fail to capture the transmission of cholera within impacted populations. Since the mode of cholera outbreaks can transition from epidemic to endemic, a comprehensive transmission model is needed to achieve timely and reliable prediction with respect to quantitative environmental risk. Here, we discuss progression of the trigger module associated with both epidemic and endemic cholera, in the context of the autochthonous aquatic nature of the causative agent of cholera, V. cholerae, as well as disease prediction.

Diarrhea treatment center (DTC) based diarrheal disease surveillance in settlements in the wake of the mass influx of forcibly displaced Myanmar national (FDMN) in Cox's Bazar, Bangladesh, 2018

BACKGROUND

In August 2017, after a large influx of forcibly displaced Myanmar nationals (FDMN) in Cox's Bazar, Bangladesh diarrhea treatment centers (DTCs) were deployed. This study aims to report the clinical, epidemiological, and laboratory characteristics of the hospitalized patients.

METHODS

The study followed cross-sectional design. In total 1792 individuals were studied. Other than data, a single, stool specimen was subjected to one step rapid visual diagnostic test for Vibrio cholerae. The provisionally diagnosed specimens of cholera cases were inoculated into Cary-Blair Transport Medium; then sent to the laboratory of icddr,b in Dhaka to isolate the colony as well as perform antibiotic susceptibility tests. Data were analyzed by STATA and analyses included descriptive as well as analytic methods.

RESULTS

Of the total 1792 admissions in 5 DTCs, 729 (41%) were from FDMN settlements; children <5 years contributed the most (n = 981; 55%). Forty percent (n = 716) were aged 15 years and above, and females were predominant (n = 453; 63%). Twenty-eight percent (n = 502) sought treatment within 24h of the onset of diarrhea. FDMN admissions within 24h were low compared to host hospitalization (n = 172, 24% vs. n = 330, 31%; p<0.001). Seventy-two percent (n = 1295) had watery diarrhea; more common among host population than FDMN (n = 802; 75% vs. n = 493; 68%; p<0.001). Forty-four percent admissions (n = 796) had some or severe dehydration, the later was common in FDMN (n = 46; 6% vs. n = 36; 3%, p = 0.005). FDMN often used public taps (n = 263; 36%), deep tube-well (n = 243; 33%), and shallow tube well (n = 188; 26%) as the source of drinking water. Nearly 96% (n = 698) of the admitted FDMN used pit latrines as opposed to 79% (n = 842) from the host community (p<0.001). FDMN children were often malnourished. None of the FDMN reported cholera.

CONCLUSION

No diarrhea outbreak was detected, but preparedness for surges and response readiness are warranted in this emergency and crisis setting.

Forms of Health System Fragmentation During Conflict: The Case of Yemen

The continuous and protracted conflict in Yemen has evolved into the worst humanitarian situation in modern history. All public structures in the country, including the health system and its basic functions, have been under tremendous pressures. One of the key obstacles to improve the health outcomes in Yemen is fragmentation of the health system. This study aims at exploring and documenting the forms of health system fragmentation in humanitarian and conflict-affected contexts by studying Yemen as a case study. We collected national qualitative data from key informants through in-depth interviews. A pool of respondents was identified from the Ministry of Public Health and Population, donors, and non-governmental organizations. Data were collected between May and June 2019. We interviewed eight key informants and reviewed national health policy documents, and references provided by key informants. Interviews were recorded, transcribed, and analyzed using qualitative content analysis. We further conducted a literature review to augment and triangulate the findings. Six themes emerged from our datasets and analyses, representing various forms of fragmentation: political, structural, inter-sectoral, financial, governance, and health agenda-related forms. Health system fragmentation in Yemen existed before the conflict eruption and has aggravated as the conflict evolves. The humanitarian situation and the collapsing health system enabled the influx of various national and international health actors. In conclusion, the protracted conflict and fragile situation in Yemen have accentuated the fragmentation of the health system. Addressing these fragmentations' forms by all health actors and building consensus on health system agenda are recommended. Health system analysis and in-depth study of fragmentation drivers in Yemen can be beneficial to build common ground and priorities to reduce health system fragmentation. Furthermore, capacity building of a health system is fundamental for the humanitarian development nexus, health system integration, and recovery efforts in the future.

Cholera Outbreak in Hadhramout, Yemen: The Epidemiological Weeks 2019

Background and aims: Cholera is a disease of acute watery diarrhea caused by Vibrio cholerae usually transmitted through contaminated water. In this study, we collected and analyzed the related epidemiological data to determine cholera outbreak in Hadhramout, Yemen during the disease epidemic in 2019. Methods: A cross-sectional study was conducted according to screening rapid diagnostic and confirmatory laboratory culture testing methods for diagnosing clinically cholera cases. Results: Suspected cholera cases were tested by rapid diagnostic test (RDT) and 399 (50.5%) out of 794 cases were determined positive, and 76(9.6%) of them were confirmed by laboratory culture test (LCT) with statistically significant difference. Serotype V. cholerae O1 was also detected in patients’ diarrhea. Females were the most affected by the disease manifested in 201 (25.3%) and 43 (5.4%) when tested by RDT and LCT, respectively, with no statistically significant difference. The highest proportion of cholera cases (224) were reported in the age group less than 15 years (56.1%) with statistically significant difference when tested by RDT, and 45(13.3%) when tested by LCT with insignificant statistics difference. Hajr directorate was revealed to be the most affected with 242 (30.47%) followed by Mukalla city directorate with 108 (13.60%) when the cases were tested by RDT; while Hajr and Mukalla city directorates reported 55 (7.0%) and 15 (2.0%), respectively, when it was confirmed by LCT with a statistically significant difference. Conclusion: Severe cholera outbreak occurred during the epidemiological weeks in 2019 in Hadhramout coast. V. cholerae O1 serotype was the causative agent of cholera. Females and age group less than 15 years were the most affected by the disease. Hajr and Mukalla city directorates reported serious outbreak cholera cases.

Severe dehydration among cholera patients in Yemen: A cohort profile

Introduction

Introduction Cholera, an acute diarrheal illness caused by ingestion of food or water contaminated with Vibrio cholerae, is one of the major causes of morbidity and mortality globally. The occurrence of outbreaks of cholera are difficult to prevent in low and middle-income countries, especially those under armed conflicts.

Methods

This study aimed to describe the characteristics of a cohort of inpatients with cholera in two main hospitals in Taiz and Sana'a, Yemen, between 3^rd February 2017 and 8^th December 2017. Patient data were entered into an excel database and analyzed using STATA 16.1. Descriptive summaries of patient's data were presented as frequencies and percentages. Patients' demographic and clinical characteristics were compared using the Chi-square test.

Results

Preliminary findings from 172 hospitalizations for cholera during the study period include 163 that were severely dehydrated (94.8%). Age, education, hand hygiene, sanitation, water source, stool content and malnutrition were significantly associated with severe dehydration.

Conclusions

This data contributes to a greater understanding of the associated risk factors for the occurrence of the infectious disease in the study region. Future study will analyze the risks for severe dehydration and diarrhea, and the associated healthcare costs.

Conflict Resilience of Water and Energy Supply Infrastructure: Insights from Yemen

Political instability and conflicts are contemporary problems across the Middle East. They threaten not only basic security, but also infrastructure performance. Supply infrastructure, providing basic services such as water and electricity, has been subjected to damage, capacity deterioration, and the bankruptcy of public providers. Often, in conflict countries such as Yemen, the continuity of basic supply is only possible thanks to adaptation efforts on the community and household levels. This paper examines the conflict resilience of water and energy supply infrastructure in Yemen during the armed conflict 2015–today. It contributes to resilience studies by linking knowledge on state fragility and conflicts, humanitarian aid, and infrastructure resilience. The paper presents adaptation responses of communities and public entities in the water and energy sectors in Yemen and critically evaluates these responses from the perspective of conflict resilience of infrastructure. The gained insights reaffirm the notion about the remarkable adaptive capacities of communities during conflicts and the importance of incorporating community-level adaptation responses into larger efforts to enhance the conflict resilience of infrastructure systems.

Antimicrobial resistance in enteric bacteria: current state and next-generation solutions

Antimicrobial resistance is one of the largest threats to global health and imposes substantial burdens in terms of morbidity, mortality, and economic costs. The gut is a key conduit for the genesis and spread of antimicrobial resistance in enteric bacterial pathogens. Distinct bacterial species that cause enteric disease can exist as invasive enteropathogens that immediately evoke gastrointestinal distress, or pathobionts that can arise from established bacterial commensals to inflict dysbiosis and disease. Furthermore, various environmental reservoirs and stressors facilitate the evolution and transmission of resistance. In this review, we present a comprehensive discussion on circulating resistance profiles and gene mobilization strategies of the most problematic species of enteric bacterial pathogens. Importantly, we present emerging approaches toward surveillance of pathogens and their resistance elements as well as promising treatment strategies that can circumvent common resistance mechanisms.

The practice of evaluating epidemic response in humanitarian and low-income settings: a systematic review

BACKGROUND

Epidemics of infectious disease occur frequently in low-income and humanitarian settings and pose a serious threat to populations. However, relatively little is known about responses to these epidemics. Robust evaluations can generate evidence on response efforts and inform future improvements. This systematic review aimed to (i) identify epidemics reported in low-income and crisis settings, (ii) determine the frequency with which evaluations of responses to these epidemics were conducted, (iii) describe the main typologies of evaluations undertaken and (iv) identify key gaps and strengths of recent evaluation practice.

METHODS

Reported epidemics were extracted from the following sources: World Health Organization Disease Outbreak News (WHO DON), UNICEF Cholera platform, Reliefweb, PROMED and Global Incidence Map. A systematic review for evaluation reports was conducted using the MEDLINE, EMBASE, Global Health, Web of Science, WPRIM, Reliefweb, PDQ Evidence and CINAHL Plus databases, complemented by grey literature searches using Google and Google Scholar. Evaluation records were quality-scored and linked to epidemics based on time and place. The time period for the review was 2010-2019.

RESULTS

A total of 429 epidemics were identified, primarily in sub-Saharan Africa, the Middle East and Central Asia. A total of 15,424 potential evaluations records were screened, 699 assessed for eligibility and 132 included for narrative synthesis. Only one tenth of epidemics had a corresponding response evaluation. Overall, there was wide variability in the quality, content as well as in the disease coverage of evaluation reports.

CONCLUSION

The current state of evaluations of responses to these epidemics reveals large gaps in coverage and quality and bears important implications for health equity and accountability to affected populations. The limited availability of epidemic response evaluations prevents improvements to future public health response. The diversity of emphasis and methods of available evaluations limits comparison across responses and time. In order to improve future response and save lives, there is a pressing need to develop a standardized and practical approach as well as governance arrangements to ensure the systematic conduct of epidemic response evaluations in low-income and crisis settings.

Prevalence and diversity of enteric pathogens among cholera treatment centre patients with acute diarrhea in Uvira, Democratic Republic of Congo

BACKGROUND

Cholera remains a major global health challenge. Uvira, in the Democratic Republic of the Congo (DRC), has had endemic cholera since the 1970's and has been implicated as a possible point of origin for national outbreaks. A previous study among this population, reported a case confirmation rate of 40% by rapid diagnostic test (RDT) among patients at the Uvira Cholera Treatment Centre (CTC). This study considers the prevalence and diversity of 15 enteric pathogens in suspected cholera cases seeking treatment at the Uvira CTC.

METHODS

We used the Luminex xTAG® multiplex PCR to test for 15 enteric pathogens, including toxigenic strains of V. cholerae in rectal swabs preserved on Whatman FTA Elute cards. Results were interpreted on MAGPIX® and analyzed on the xTAG® Data Analysis Software. Prevalence of enteric pathogens were calculated and pathogen diversity was modelled with a Poisson regression.

RESULTS

Among 269 enrolled CTC patients, PCR detected the presence of toxigenic Vibrio cholerae in 38% (103/269) of the patients, which were considered to be cholera cases. These strains were detected as the sole pathogen in 36% (37/103) of these cases. Almost half (45%) of all study participants carried multiple enteric pathogens (two or more). Enterotoxigenic Escherichia coli (36%) and Cryptosporidium (28%) were the other most common pathogens identified amongst all participants. No pathogen was detected in 16.4% of study participants. Mean number of pathogens was highest amongst boys and girls aged 1-15 years and lowest in women aged 16-81 years. Ninety-three percent of toxigenic V. cholerae strains detected by PCR were found in patients having tested positive for V. cholerae O1 by RDT.

CONCLUSIONS

Our study supports previous results from DRC and other cholera endemic areas in sub-Sahara Africa with less than half of CTC admissions positive for cholera by PCR. More research is required to determine the causes of severe acute diarrhea in these low-resource, endemic areas to optimize treatment measures.

TRIAL REGISTRATION

This study is part of the impact evaluation study entitled: "Impact Evaluation of Urban Water Supply Improvements on Cholera and Other Diarrheal Diseases in Uvira, Democratic Republic of Congo" registered on 10 October 2016 at clinicaltrials.gov Identification number: NCT02928341 .

Cholera knowledge, socioeconomic and WaSH characteristics in Aden - Yemen, 2017: a community-based comparative survey

OBJECTIVES

To improve prevention and control response to the cholera outbreak, we sought to assess and compare the community's cholera awareness and needs in high and low epidemic areas in Aden.

METHODS

A community-based comparative survey was conducted in 2017. We used multi-stage cluster sampling. Eligible household heads in high and low epidemic areas were interviewed. The data collected from both areas using a pretested questionnaire.

RESULTS

Cholera cases and mortality were higher in high epidemic areas compared with low epidemic areas. Socioeconomic, water, sanitation, and hygienic conditions were poorer in high epidemic areas compared with low epidemic areas. Knowledge of cholera transmission and prevention was sub-optimal in both areas. We found a mismatch between the delivered education and distributed preventive materials.

CONCLUSIONS

Stakeholders should tailor the design, content, and implementation of future cholera prevention and control methods to meet the needs of the community. Future educational camping should focus on the transmission prevention, including vaccination. Education and sustainable interventions should be implemented to improve the water, sanitation, and hygiene.

Health-related publications on people living in fragile states in the alert zone: a bibliometric analysis

Background

Fragile states pose a global challenge. Assessing health research activity on people living in these states can help identify neglected health domains in fragile settings. The objective of the current study was to assess and describe health research activity on people living in fragile states in the alert zone.

Method

A bibliometric method was applied using SciVerse Scopus. Research articles published on people in fragile states in the alert zone were retrieved and analyzed. The Fragile State Index (FSI) score was used for selection of states in the alert zone. The analysis was limited to 1 year; 2018.

Results

The search query found 2299 research articles giving an average of 2 research articles per one million population per year in the selected fragile states. The number of research articles per one million population was not significantly correlated (p = 0.053; r = − 0.349) with FSI scores. However, it was significantly correlated with the extent of international research collaboration (p < 0.01, r = 065). Research on communicable diseases was the largest research domain (763 articles; 33.2%) followed by maternal/women’s health (430 articles; 18.7%), non-communicable diseases (291 articles; 12.7%), health system/policy (271 articles; 11.8%) and psychosocial and mental health (89; 3.9%). There were three research themes in the research domain of infectious diseases: HIV/AIDS; water-borne infectious diseases; and miscellaneous infectious diseases such as tuberculosis and malaria. The top ten cited articles were mainly on infectious diseases, particularly on malaria and Lassa fever. Of all the retrieved documents, 727 (31.6%) research articles appeared in national/regional journals while the remaining appeared in international journals. The World Health organization was the most active funding organization for research on fragile states. Top ten active institutions were mainly based in fragile states with the lowest FSI score, specifically Ethiopia, Uganda, Nigeria, and Pakistan.

Conclusion

Research on fragile states was relatively low. Research on mental health and health system/policy should be encouraged. Collaboration and funding might help academic institutions in fragile states to make health problems in these countries more visible.

Unique challenges to control the spread of COVID-19 in the Middle East

The COVID-19 pandemic is spreading at unprecedented pace among the Middle East and neighboring countries. This region is geographically, economically, politically, culturally and religiously a very sensitive area, which impose unique challenges for effective control of this epidemic. These challenges include compromised healthcare systems, prolonged regional conflicts and humanitarian crises, suboptimal levels of transparency and cooperation, and frequent religious gatherings. These factors are interrelated and collectively determine the response to the pandemic in this region. Here, we in-depth emphasize these challenges and take a glimpse of possible solutions towards mitigating the spread of COVID-19.

Yemen's Cholera Epidemic Is a One Health Issue

Yemen has been faced with the worst cholera epidemic of modern times, with more than 1 million suspected cases and 3000 deaths at the time of writing. This problem is largely due to the longstanding civil war between pro-government forces and the Houthi armed movement, which has severely damaged already vulnerable sanitation and healthcare facilities and systems in the country. It is further compounded by a dire lack of basic amenities, chronic malnutrition, and unfavourable weather conditions. Another contributory component may be aerial transfer by cholera-infected chironomid insects. To contain the spread of cholera in Yemen, a nation-wide armistice should be negotiated, and national and local committees must be convened to coordinate efforts on the ground. Community isolation facilities with proper sanitation, reliable disposal systems, and a clean water supply should be set up to isolate and treat sick patients. The continuity of vaccination programmes should be ensured. Public health campaigns to educate local communities about good hygiene practices and nutrition are also necessary. The One Health paradigm emphasizes a multi-sectoral and transdisciplinary understanding and approach to prevent and mitigate the threat of communicable diseases. This paradigm is highly applicable to the ongoing cholera crisis in Yemen, as it demands a holistic and whole-of-society approach at the local, regional, and national levels. The key stakeholders and warring parties in Yemen must work towards a lasting ceasefire during these trying times, especially given the extra burden from the mounting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak worldwide.

Armed conflict, a neglected determinant of childhood vaccination: some children are left behind

Vaccination is an indisputable intervention that has tremendously mitigated the global burden of vaccine-preventable diseases (VPDs). The number of armed conflicts globally seems to be at an all-time high, with devastating effects on vaccination coverage. This paper will examine how armed conflicts affect childhood vaccination and lead to the reemergence and spread of VPDs. Unarguably, socioeconomic factors, population demographics, the apparent long vaccination timetable, multiple vaccine doses, lack of trust in vaccination processes and the rumor of the adverse effects of some vaccines unnerve some parents and create a puzzle. By bringing under the global floodlight, the impact of armed conflicts which contextually affect vaccination coverage, this article will help strengthen the advocacy for vaccination, and call for the fortification of existing treaties on the rule of engagement during conflicts. In order to eliminate or eradicate VPDs, strategies to reach children that are left behind during conflicts is paramount.