Staphylococcal food poisoning aboard a commercial aircraft

Factors of Airline Selection and Reflight Intention During the Pandemic/Case of Serbian Airlines Users

The global pandemic coronavirus disease 2019 (COVID-19) has caused significant economic changes for all segments of the economy. Travel restrictions have landed several commercial airlines and significantly reduced their revenues. Safety measures are strict and very demanded, especially when it comes to food drinks and beverages served during flights. This article aims to discover the predictors that influenced the intention of the airline’s passengers to travel long-distance flights in unusual conditions of the COVID-19 pandemic and differs from current studies on airline selection and passenger loyalty because it includes changes in the behavior of employees who regularly fly medium- and long-distance flights. Requirements for passenger’s airline selection have been changed, which is why this study aimed to determine which factors influence the selection during reopening after lockdown. Determinants of food quality and safety during flights are a long-term challenge and could affect passengers’ choice of the airline they want to fly. This study was conducted during the reopening period of airlines, during the COVID-19 pandemic, on a sample of 369 Serbian passengers and employees on medium- and long-distance flights, in the period from November 20, 2020 to January 15, 2021. Regression analysis concluded that certain predictors such as food service quality and safety significantly affect the attitude, subjective norms, and perceived behavioral control (PBC) of passengers and trigger the intention that affects behaviors in the choice of the airline during the COVID-19 pandemic, especially when it comes to the flights with medium and long durations. To better interpret the effects, a path analysis was performed in the SPSS Analysis of Moment Structures (AMOS) software, version 26.00 with the aim to examine the importance and significance of causal relationships between groups of variables. The results confirmed the theory of planned behavior; that intentions are a significant mediator between the mentioned independent variables (attitudes about quality and safety of food, drinks and beverages, subjective norms, and perceived behavior control) and passenger behavior when rechoosing the same airline.

In-flight transmission of foodborne disease: How can airlines improve?

Food contamination during air travel presents unique risks to those affected. Foodborne pathogens can cause serious illness among all on board, and potentially jeopardize flight safety. These risks are likely to increase with current trends of "densification" and a predicted massive expansion of air travel. While aircraft are being equipped with ever newer designs with a focus on efficiency and comfort, regulations remained largely unmodified in terms of basic hygiene requirements. Strict guidelines for food hygiene exist for on-ground food settings and catering kitchens. There is uncertainty about hygiene standards on board commercial aircraft, and little regulatory oversight of what happens to food in-flight. In two hypothetical scenarios we indicate the potential risks associated with poor food handling practice onboard aircraft, with the ultimate aim of bringing aviation food safety in line with on-ground regulations. Changes in cabin design alongside adequate training in safe food handling have the potential to increase public health protection. We urge a review of existing in-flight hygiene protocols to better direct the development of regulation, prevention, and intervention measures for aviation food safety.

The Role of Regulatory Mechanisms and Environmental Parameters in Staphylococcal Food Poisoning and Resulting Challenges to Risk Assessment

Prevention, prediction, control, and handling of bacterial foodborne diseases - an ongoing, serious, and costly concern worldwide - are continually facing a wide array of difficulties. Not the least due to that food matrices, highly variable and complex, can impact virulence expression in diverse and unpredictable ways. This review aims to present a comprehensive overview of challenges related to the presence of enterotoxigenic Staphylococcus aureus in the food production chain. It focuses on characteristics, expression, and regulation of the highly stable staphylococcal enterotoxins and in particular staphylococcal enterotoxin A (SEA). Together with the robustness of the pathogen under diverse environmental conditions and the range of possible entry routes into the food chain, this poses some of the biggest challenges in the control of SFP. Furthermore, the emergence of new enterotoxins, found to be connected with SFP, brings new questions around their regulatory mechanisms and expression in different food environments. The appearance of increasing amounts of antibiotic resistant strains found in food is also highlighted. Finally, potentials and limitations of implementing existing risk assessment models are discussed. Various quantitative microbial risk assessment approaches have attempted to quantify the growth of the bacterium and production of disease causing levels of toxin under various food chain and domestic food handling scenarios. This requires employment of predictive modeling tools, quantifying the spatiotemporal population dynamics of S. aureus in response to intrinsic and extrinsic food properties. In this context, the armory of predictive modeling employs both kinetic and probabilistic models to estimate the levels that potentiate toxin production, the time needed to reach that levels, and overall, the likelihood of toxin production. Following risk assessment, the main challenge to mitigate the risk of S. aureus intoxication is first to prevent growth of the organism and then to hamper the production of enterotoxins, or at least prevent the accumulation of high levels (e.g., >10-20 ng) in food. The necessity for continued studies indeed becomes apparent based on the challenges to understand, control, and predict enterotoxin production in relation to the food environment. Different types of food, preservatives, processing, and packaging conditions; regulatory networks; and different staphylococcal enterotoxin-producing S. aureus strains need to be further explored to obtain more complete knowledge about the virulence of this intriguing pathogen.

Staphylococcus aureus and staphylococcal food-borne disease: an ongoing challenge in public health

Staphylococcal food-borne disease (SFD) is one of the most common food-borne diseases worldwide resulting from the contamination of food by preformed S. aureus enterotoxins. It is one of the most common causes of reported food-borne diseases in the United States. Although several Staphylococcal enterotoxins (SEs) have been identified, SEA, a highly heat-stable SE, is the most common cause of SFD worldwide. Outbreak investigations have found that improper food handling practices in the retail industry account for the majority of SFD outbreaks. However, several studies have documented prevalence of S. aureus in many food products including raw retail meat indicating that consumers are at potential risk of S. aureus colonization and subsequent infection. Presence of pathogens in food products imposes potential hazard for consumers and causes grave economic loss and loss in human productivity via food-borne disease. Symptoms of SFD include nausea, vomiting, and abdominal cramps with or without diarrhea. Preventive measures include safe food handling and processing practice, maintaining cold chain, adequate cleaning and disinfection of equipment, prevention of cross-contamination in home and kitchen, and prevention of contamination from farm to fork. This paper provides a brief overview of SFD, contributing factors, risk that it imposes to the consumers, current research gaps, and preventive measures.

International outbreak investigation of Salmonella Heidelberg associated with in-flight catering

Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10.2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

Staphylococcus aureus and its food poisoning toxins: characterization and outbreak investigation

Staphylococcal food poisoning (SFP) is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs) preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All of them have superantigenic activity whereas half of them have been proved to be emetic, representing a potential hazard for consumers. This review, divided into four parts, will focus on the following: (1) the worldwide story of SFP outbreaks, (2) the characteristics and behaviour of S. aureus in food environment, (3) the toxinogenic conditions and characteristics of SEs, and (4) SFP outbreaks including symptomatology, occurrence in the European Union and currently available methods used to characterize staphylococcal outbreaks.

Food-poisoning and commercial air travel

With the introduction of budget airlines and greater competitiveness amongst all airlines, air travel has now become an extremely popular form of travel, presenting its own unique set of risks from food poisoning. Foodborne illness associated with air travel is quite uncommon in the modern era. However, when it occurs, it may have serious implications for passengers and when crew are affected, has the potential to threaten safety. Quality, safe, in-flight catering relies on high standards of food preparation and storage; this applies at the airport kitchens (or at subcontractors' facilities), on the aircraft and in the transportation vehicles which carry the food from the ground source to the aircraft. This is especially challenging in certain countries. Several foodborne outbreaks have been recorded by the airline industry as a result of a number of different failures of these systems. These have provided an opportunity to learn from past mistakes and current practice has, therefore, reached such a standard so as to minimise risk of failures of this kind. This review examines: (i) the origin of food safety in modern commercial aviation; (ii) outbreaks which have occurred previously relating to aviation travel; (iii) the microbiological quality of food and water on board commercial aircraft; and (iv) how Hazard Analysis Critical Control Points may be employed to maintain food safety in aviation travel.

Profile of food handlers working in food service establishments located within the premises of a medical college in Delhi, India

OBJECTIVES

To find out: (1) the socio-demographic and professional characteristics of food handlers working in food service establishments located in the campus of a medical college in New Delhi, (2) the prevalence of morbid conditions among them and their health-care-seeking behaviour and immunization status.

STUDY DESIGN

Cross-sectional study

METHODS

A total of 151 food handlers working in 18 food service establishments were interviewed regarding their socio-demographic and professional characteristics, history of substance use, disease if any and health care sought for it, immunization status and pre-placement and in-service medical examination. They were also subjected to clinical examination. Stool examination was done for 129 study subjects.

RESULTS

The majority were less than 40 years of age (60.3%), male (97.4%), Hindu (95.3%), literate (80.1%) and had the habit of substance use (75.5%). Most of them (94.7%) had one or more morbid conditions, important ones being dental caries (50.3%), worm infestation (41.1%) and injuries/burns on hands (39.7%). The health seeking behaviour, immunization status in relation to enteric group of fevers and tetanus and pre-placement and in-service medical examination were observed to be unsatisfactory.

CONCLUSION

The findings of the study highlight the need of creating awareness among food handlers about various measures of maintaining food hygiene and ensuring their good health through pre-placement and inservice medical examination.

Real-time quantitative PCR of Staphylococcus aureus and application in restaurant meals

Staphylococcus aureus is considered the second most common pathogen to cause outbreaks of food poisoning, exceeded only by Campylobacter. Consumption of foods containing this microorganism is often identified as the cause of illness. In this study, a rapid, reliable, and sensitive real-time quantitative PCR was developed and compared with conventional culture methods. Real-time quantitative PCR was carried out by purifying DNA extracts of S. aureus with a Staphylococcus sample preparation kit and quantifying it in the LightCycler system with hybridization probes. The assay was linear from a range of 10 to 10(6) S. aureus cells (r2 > 0.997). The PCR reaction presented an efficiency of >85%. Accuracy of the PCR-based assay, expressed as percent bias, was around 13%, and the precision, expressed as a percentage of the coefficient of variation, was 7 to 10%. Intraday and interday variability were studied at 10(2) CFU/g and was 12 and 14%, respectively. The proposed method was applied to the analysis of 77 samples of restaurant meals in Valencia (Spain). In 11.6% of samples S. aureus was detected by real-time quantitative PCR, as well as by the conventional microbiological method. An excellent correspondence between real-time quantitative PCR and microbiological numbers (CFU/g) was observed with deviations of < 28%.

Airplanes and Infectious Disease

Air travel is associated with crowded conditions that can facilitate the transmission of airborne infectious diseases. The risk of contracting such diseases depends on the presence of an infected person who is shedding infectious particles and sufficient exposure of a sensitive person to achieve an adequate dose to cause disease. Proximity to the infectious person and the length of time spent near the person are the most important risks for contracting a disease. Ventilation patterns play a lesser role in disease transmission. Well-documented outbreaks of influenza, severe acute respiratory syndrome (SARS), and tuberculosis have occurred. Other common respiratory illnesses have probably also been spread via aircraft, but outbreaks remain unrecognized. Research on the spread of infectious disease in aircraft has focused on sampling for microorganisms in air (which has little relevance), and on the development of models to predict the risks for specific diseases.

Nosocomial antibiotic-associated diarrhea associated with enterotoxin-producing strains of methicillin-resistant Staphylococcus aureus

OBJECTIVES

The aim of this study is to present new evidence that enterotoxin-producing strains of methicillin-resistant Staphylococcus aureus may cause nosocomial antibiotic-associated diarrhea.

METHODS

We conducted a prospective study that utilized standard methods to exclude other bacterial, parasitic, and viral pathogens as causes of nosocomial diarrhea in patients with heavy growth of methicillin-resistant S. aureus in their stool. Staphylococcal enterotoxin assays were performed on S. aureus strains recovered from patients' stools and on stool specimens from affected patients. Retrospective cohort studies compared the severity of diarrhea in patients with methicillin-resistant S. aureus-associated diarrhea with that of patients whose stool did not contain the organism and with patients colonized or infected with enterotoxin-negative methicillin-resistant S. aureus strains.

RESULTS

During an 18-month period, 11 patients had nosocomial antibiotic-associated diarrhea associated with enterotoxin-producing strains of methicillin-resistant S. aureus. Other common bacterial, parasitic, and viral pathogens were excluded. S. aureus strains from the 11 patients produced staphylococcal enterotoxin A, A and B, or D. Eighty-nine percent of patients had the same enterotoxin(s) in stool specimens as produced by the strain recovered from their stool. Case patients had a greater number of days of diarrhea than patients without methicillin-resistant S. aureus in their stool (p < 0.001), or randomly selected patients colonized or infected with enterotoxin-negative methicillin-resistant S. aureus (p < 0.001).

CONCLUSIONS

Our findings provide evidence that enterotoxin-producing strains of methicillin-resistant S. aureus may cause nosocomial antibiotic-associated diarrhea. Greater recognition of this disease should result in more rapid and appropriate treatment of affected patients.

Transmission of infectious diseases during commercial air travel

Because of the increasing ease and affordability of air travel and mobility of people, airborne, food-borne, vector-borne, and zoonotic infectious diseases transmitted during commercial air travel are an important public health issue. Heightened fear of bioterrorism agents has caused health officials to re-examine the potential of these agents to be spread by air travel. The severe acute respiratory syndrome outbreak of 2002 showed how air travel can have an important role in the rapid spread of newly emerging infections and could potentially even start pandemics. In addition to the flight crew, public health officials and health care professionals have an important role in the management of infectious diseases transmitted on airlines and should be familiar with guidelines provided by local and international authorities.

Estimation of tuberculosis risk on a commercial airliner

This article estimates the risk of tuberculosis (TB) transmission on a typical commercial airliner using a simple one box model (OBM) and a sequential box model (SBM). We used input data derived from an actual TB exposure on an airliner, and we assumed a hypothetical scenario that a highly infectious TB source case (i.e., 108 infectious quanta per hour) travels as a passenger on an 8.7-hour flight. We estimate an average risk of TB transmission on the order of 1 chance in 1,000 for all passengers using the OBM. Applying the more realistic SBM, we show that the risk and incidence decrease sharply in a stepwise fashion in cabins downstream from the cabin containing the source case assuming some potential for airflow from more contaminated to less contaminated cabins. We further characterized spatial variability in the risk within the cabin by modeling a previously reported TB outbreak in an airplane to demonstrate that the TB cases occur most likely within close proximity of the source TB patient.

Infection and the gut

Gastrointestinal symptoms, including vomiting, are caused by a variety of infective organisms in children, many of which are self-limiting and resolve within a week, but others are potentially much more serious in their consequences. Diarrhea, vomiting and abdominal pain are common but nonspecific symptoms. Investigation is dictated by the likely causative organism, given the age and presentation of the child. The role of bacteria in the pathogenesis of necrotizing enterocolitis, recognition that Yersinia, Campylobacter and Salmonella may produce symptoms difficult to distinguish clinically from appendicitis, the viral causes of idiopathic intussusception, the occurrence of intussusception after administration of rotavirus vaccine, and the evidence incriminating mycobacterium avium subspecies paratuberculosis in the aetiology of Crohn disease are discussed.

Genotypes and enterotoxicity of Staphylococcus aureus isolated from the hands and nasal cavities of flight-catering employees

Hand and nasal samples of flight-catering staff were collected from 1995 to 1997 to find employees carrying Staphylococcus aureus. Altogether 153 hand samples and 136 nose samples were taken. Nasal sampling showed a higher prevalence of S. aureus among food handlers (29%) than hand sampling (9%). A high proportion of the strains (46%) were enterotoxigenic, and a considerable amount of food handlers carried enterotoxigenic S. aureus, 6% and 12% according to hand and nasal sampling, respectively. Pulsed-field gel electrophoresis macrorestriction profiles revealed a total of 32 different types associated with the 35 employees carrying S. aureus. In most cases, the same type colonized both the hand and nose of a person. Despite the wide variety of types found, one strain colonized five persons and the second most common strain was associated with four food handlers. The predominant toxin produced was B, which was produced by the most common strain. The results showed that nasal sampling is a good way to detect S. aureus carriers, whereas hand sampling may fail to reveal carriers. The high proportion of enterotoxigenic strains show that a food handler harboring S. aureus must be considered a potential source of enterotoxigenic strains for airline meals.

Secretory diarrhea in children: newly recognized toxins and hormone-secreting tumors

This review of bacterial toxins and hormones that stimulate diarrhea shows that we have learned much concerning the pathophysiology of these diarrheal states; however, we have much yet to learn. It is hoped that research will continue to enlighten us with regard to the pathophysiology, diagnosis, and treatment for these disease processes.

The application of hazard analysis critical control point (HACCP) in a flight catering establishment improved the bacteriological quality of meals

Following an outbreak of salmonellosis affecting 415 passengers on flights in 1991, the associated flight catering establishment located on a Greek island was surveyed for two years. During the first year of the survey, the bacteriological quality of food was not satisfactory. In an attempt to maximize food safety for crew and passengers the HACCP approach was implemented in 1993. Since its application, greatly supported by the management and staff, the bacteriological quality of aircraft meals was considerably improved.

Distribution of enterotoxigenic Staphylococcus aureus in ready-to-eat foods in eastern Nigeria

Out of 880 samples of commonly consumed meat, fish and vegetable ready-to-eat foods from eastern Nigeria examined, 552 (62%) yielded coagulase-positive Staphylococcus aureus, with 269 (48%) of the strains being enterotoxigenic. Two cowpea-based foods, akara and moin moin, whose methods of preparation and sale involve little or no post-processing hand contact, contained the smallest numbers of S. aureus. All the water samples from food preparation centres analysed, which had repeated hand contact during food preparation, yielded coagulase-positive S. aureus. Generally, organisms producing enterotoxin A were the most frequently encountered, followed by producers of enterotoxin B. Among fish samples, however, the predominant strains were producers of enterotoxin B and enterotoxin A, in that order. The frequency of enterotoxins C- and D-producing strains was about the same for the samples investigated.

Medical aspects of commercial air travel

Commercial airline travel is so fast and easy that it attracts many people with significant underlying chronic disease. Although most airlines claim no ill effects from the stresses of air travel, airlines that fly longer routes tend to report a higher incidence of in-flight emergencies and sudden deaths than those that fly shorter routes. Reasons for these differences are discussed. The Federal Aviation Administration has recently upgraded the first aid kits carried by the airlines. Airlines must now report all untoward medical incidents to the government; this policy will permit the collection of better data concerning the true incidence of in-flight emergencies. Future studies should be oriented toward an analysis of the first aid kit's effectiveness and deficiencies. Emergency physicians are often required to make recommendations concerning the advisability of travel for patients who become ill away from home. Better criteria exist for making well-informed decisions for patients with obstructive pulmonary disease than for patients with other chronic diseases. A series of studies has suggested that physicians should recommend supplemental oxygen for normocapnic jet passengers who have a resting preflight Pao2 (at sea level) less than 67 mmHg. If available, preflight altitude stress testing should be performed on hypercapnic obstructive airways patients who request permission to fly. Poorly supported recommendations have been promulgated by several major professional organizations concerning flight advisability in a wide variety of other diseases. If these recommendations are followed strictly, people who become ill away from home can expect significant difficulty in returning home shortly after hospital discharge.

Clinical aspects of outbreak of staphylococcal food poisoning during air travel

An outbreak of staphylococcal food poisoning among 364 charter-flight passengers and crew members is described. Symptoms appeared just before landing, about an hour after a meal containing contaminated ham had been served. 143 passengers were admitted to hospital. 1 patient developed acute anuria and 1 had hemiplegia and aphasia; both recovered. Fever and bloody stools were recorded with unusual frequency.