Human campylobacteriosis related to the consumption of raw milk sold by vending machines in Italy: Quantitative risk assessment based on official controls over four years

Nourishing the Human Holobiont to Reduce the Risk of Non-Communicable Diseases: A Cow’s Milk Evidence Map Example

The microbiome revolution brought the realization that diet, health, and safety for humans in reality means diet, health, and safety for the human holobiont/superorganism. Eating healthier means much more than just feeding human cells. Our diet must also nourish the combination of our microbiome and our connected physiological systems (e.g., the microimmunosome). For this reason, there has been an interest in returning to ancestral “complete” unprocessed foods enriched in microbes, including raw milks. To contribute to this inevitable “nourishing the holobiont” trend, we introduce a systematic risk–benefit analysis tool (evidence mapping), which facilitates transdisciplinary state-of-the-science decisions that transcend single scientific disciplines. Our prior paper developed an evidence map (a type of risk–benefit mind map) for raw vs. processed/pasteurized human breast milk. In the present paper, we follow with a comprehensive evidence map and narrative for raw/natural vs. processed/pasteurized cow’s milk. Importantly, the evidence maps incorporate clinical data for both infectious and non-communicable diseases and allow the impact of modern agricultural, food management, and medical and veterinary monitoring outcomes to be captured. Additionally, we focus on the impact of raw milks (as “complete” foods) on the microimmunosome, the microbiome-systems biology unit that significantly determines risk of the world’s number one cause of human death, non-communicable diseases.

Raw milk producers with high levels of hygiene and safety

There is world-wide increasing interest in the consumption of unprocessed, natural food commodities including fresh (unpasteurised) milk and milk products. Consumers are actively seeking out raw milk, partly due to health reasons, but also for taste, freshness, closeness to the producer and to support local agriculture. The need for high levels of hygiene and safety in farms producing raw milk for direct consumption has long been recognised and has led to federal and industry-initiated systems for safe raw milk production. Raw milk producers in North America and Europe have demonstrated that raw milk, intended for direct consumption, can be produced safe and hygienic. The aim of this paper is to describe practices that have been developed for safe raw milk production. The German Vorzugsmilch is a federally regulated programme for legal raw milk production that was established already in the 1930s to provide raw milk with high hygienic standards controlled for zoonotic diseases to consumers. The Raw Milk Institute is a non-profit organisation established in California that has developed a voluntary safe raw milk programme in North America. RAWMI has developed a risk analysis and management system for raw milk dairy farmers to assist farmers in making individually tailored solutions for various production systems. In British Colombia, Canada, small herd share farms have employed good manufacturing practices, a risk management approach and performed monthly samples for pathogens and indicator bacteria to demonstrate safety and consistency. The major components of the raw milk systems applied, and the results of regular milk microbial indicator bacteria are presented. For the German system, the results from standard monthly pathogen tests are compared to zoonotic pathogen tests from other milk sources. The overall results indicate that raw milk can be produced with a high level of hygiene and safety in various systems.

Quantitative Microbial Risk Assessment and Infectious Disease Transmission Modeling of Waterborne Enteric Pathogens

PURPOSE OF REVIEW

Waterborne enteric pathogens remain a global health threat. Increasingly, quantitative microbial risk assessment (QMRA) and infectious disease transmission modeling (IDTM) are used to assess waterborne pathogen risks and evaluate mitigation. These modeling efforts, however, have largely been conducted independently for different purposes and in different settings. In this review, we examine the settings where each modeling strategy is employed.

RECENT FINDINGS

QMRA research has focused on food contamination and recreational water in high-income countries (HICs) and drinking water and wastewater in low- and middle-income countries (LMICs). IDTM research has focused on large outbreaks (predominately LMICs) and vaccine-preventable diseases (LMICs and HICs). Human ecology determines the niches that pathogens exploit, leading researchers to focus on different risk assessment research strategies in different settings. To enhance risk modeling, QMRA and IDTM approaches should be integrated to include dynamics of pathogens in the environment and pathogen transmission through populations.

The consequences of Campylobacter infection

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the clinical, public health and economic consequences of Campylobacter infection.

RECENT FINDINGS

Campylobacter is a leading bacterial cause of food-related illness. Its importance is enhanced by the chronic sequelae that can result from acute infection. Recent advances include a new clinical classification system for neurological sequelae with the aim of speeding accurate diagnosis and appropriate treatment, a better understanding of the mechanisms underlying postinfectious functional gastrointestinal disorders, the emergence of Campylobacter concisus and Campylobacter showae as potential aetiological agents in inflammatory bowel disease, a new mechanism for antimicrobial resistance in campylobacters and a better appreciation of the economic costs.

SUMMARY

Campylobacter infection is very common and can lead to serious chronic sequelae and considerable personal, healthcare and societal costs.

Paediatric HUS Cases Related to the Consumption of Raw Milk Sold by Vending Machines in Italy: Quantitative Risk Assessment Based on Escherichia coli O157 Official Controls over 7 years

A quantitative risk assessment (RA) was developed to estimate haemolytic-uremic syndrome (HUS) cases in paediatric population associated with the consumption of raw milk sold in vending machines in Italy. The historical national evolution of raw milk consumption phenomenon since 2008, when consumer interest started to grow, and after 7 years of marketing adjustment, is outlined. Exposure assessment was based on the official Shiga toxin-producing Escherichia coli O157:H7 (STEC) microbiological records of raw milk samples from vending machines monitored by the regional Veterinary Authorities from 2008 to 2014, microbial growth during storage, consumption frequency of raw milk, serving size, consumption preference and age of consumers. The differential risk considered milk handled under regulation conditions (4°C throughout all phases) and the worst time-temperature field handling conditions detected. In case of boiling milk before consumption, we assumed that the risk of HUS is fixed at zero. The model estimates clearly show that the public health significance of HUS cases due to raw milk STEC contamination depends on the current variability surrounding the risk profile of the food and the consumer behaviour has more impact than milk storage scenario. The estimated HUS cases predicted by our model are roughly in line with the effective STEC O157-associated HUS cases notified in Italy only when the proportion of consumers not boiling milk before consumption is assumed to be 1%. Raw milk consumption remains a source of E. coli O157:H7 for humans, but its overall relevance is likely to have subsided and significant caution should be exerted for temporal, geographical and consumers behaviour analysis. Health education programmes and regulatory actions are required to educate people, primarily children, on other STEC sources.

Tracing Back Clinical Campylobacter jejuni in the Northwest of Italy and Assessing Their Potential Source

Food-borne campylobacteriosis is caused mainly by the handling or consumption of undercooked chicken meat or by the ingestion of contaminated raw milk. Knowledge about the contributions of different food sources to gastrointestinal disease is fundamental to prioritize food safety interventions and to establish proper control strategies. Assessing the genetic diversity among Campylobacter species is essential to our understanding of their epidemiology and population structure. We molecularly characterized 56 Campylobacter jejuni isolates (31 from patients hospitalized with gastroenteritis, 17 from raw milk samples, and 8 from chicken samples) using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) in order to trace the source of the disease. We also used a population genetic approach to investigate the source of the human cases from six different reservoirs of infection. MLST identified 25 different sequence types and 11 clonal complexes (CCs) (21, 658, 206, 353, 443, 48, 61, 257, 1332, 354, 574) and these included several alleles not cited previously in the PubMLST international database. The most prevalent CCs were 21, 206, and 354. PFGE showed 34 pulsotypes divided between 28 different clusters. At the fine scale, by means of PFGE and MLST, only two human cases were linked to raw milk, while one case was linked to chicken meat. The investigation revealed the presence of several genotypes among the human isolates, which probably suggests multiple foci for the infections. Finally, the source attribution model we used revealed that most cases were attributed to chicken (69.75%) as the main reservoir in Italy, followed to a lesser extent by the following sources: cattle (8.25%); environment (6.28%); wild bird (7.37%); small ruminant (5.35%), and pork (2.98%). This study confirms the importance of correlating epidemiological investigations with molecular epidemiological data to better understand the dynamics of infection.

Stability of a Tick-Borne Flavivirus in Milk

The tick-borne flaviviruses (TBFV) occur worldwide and the tick-borne encephalitis virus (TBEV) members of the group often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that the virus can be excreted in the milk of infected animals. Additionally, the virus remains infectious after exposure to low pH levels, similar to those found in the stomach. To evaluate the survival of virus in milk, we studied the stability of the BSL-2 TBFV, Langat virus, in unpasteurized goat milk over time and after different thermal treatments. Virus was stable in milk maintained under refrigeration conditions; however, there was a marked reduction in virus titer after incubation at room temperature. High temperature, short time pasteurization protocols completely inactivated the virus. Interestingly, simulation of a typical thermal regime utilized for cheese did not completely inactivate the virus in milk. These findings stress the importance of proper milk handling and pasteurization processes in areas endemic for TBEV.

Development of an Innovative Raw Milk Dispenser Based on Nanofluid Technology

This paper presents the comparative analysis of a traditional raw milk dispenser and an innovative prototype based on nanofluid technology. The traditional raw milk dispenser consists of an off-the-shelf upright air-cooled refrigerator sold on the market, whereas the innovative prototype presents a tank equipped with a serpentine tube jacket operated with Al2O3–ethylene glycol aqueous solution nanofluid. The systems are experimentally analysed in the ambient temperature range of 19–35°C to evaluate the energy performance and the temperature control of the milk tank. The innovative prototype is demonstrated to be superior from the point of view of both energy saving and food safety. In fact, the innovative prototype exhibits a 63–70% energy saving with respect to the traditional one. Furthermore, the prototype distributor is able to reach the “safe” temperature of 4°C in about half of the time required by traditional system and it keeps the milk always in the “safe” temperature range 2–3°C, while the traditional distributor displays locally milk temperature higher than 4°C.