Long-Term Health Outcomes of Foodborne Pathogens

The report from the CDC shows that foodborne illnesses are a serious public health issue in the US, causing tens of millions of acute illnesses and hundreds of thousands of hospital cases and thousands of deaths each year.

The severity of the outbreaks varies from incident to incident and is dependent on the pathogen and the vulnerability of the people who are infected.

However, the report shows that it is the young, the elderly and those people whose immune systems have been suppressed such as people undergoing chemotherapy, or pregnant women, who are most likely to be more severely affected by foodborne pathogens.

"Diarrhoea and vomiting are common symptoms, and in most cases, last for only a few days. However, most foodborne pathogens can cause, in a small percentage of cases, serious acute and/or life-long complications, including: kidney failure; paralysis; seizures; hearing/visual impairments and mental retardation," the report says.

The report analyses the known pathogens and the effect they have on consumers.

Campylobacter is generally transmitted by food and afflicts millions of Americans each year putting more than 10,000 in hospital.

The report says: "Campylobacter is associated with Guillain-Barré syndrome (GBS), the most common cause of neuromuscular paralysis in the United States. GBS patients can become permanently disabled and paralyzed; many require hospital care, and about a third of them require care at rehabilitation facilities, long-term care hospitals, and/or nursing homes."

The report adds that Campylobacter also can trigger arthritis, heart infections, and blood infections.

The CDC says that E. coli O157:H7 infection holds a great risk for children, especially those in the younger age groups.

"Children have the highest incidence rate and are at the greatest risk for developing serious complications," the report says.

"E. coli O157:H7 can develop into hemolytic uremic syndrome (HUS), the leading cause of acute kidney failure in children in the United States. HUS can lead to death, or in some cases to long-term or permanent health problems, including end-stage kidney disease, neurological complications, and insulin-dependent diabetes."

Thousands of Americans are infected by Listeria monocytogenes every year, nearly all of them from contaminated food.

Listeria monocytogenes has also been associated with infections of the brain and the spinal cord.

The report says that this aspect of infection can result in serious neurological dysfunctions or death.

Most reported cases occur in children about four years old, and about one in five people afflicted die as a result of the infection.

Listeriosis can also cause miscarriages in pregnant women or premature or still births.

"Listeriosis survivors often are left with serious neurological dysfunctions, including seizures, paralysis, and impaired ability to see, hear, swallow, or speak," says the report.

"Severe cases often result in partial to total impairment and can require life-long residential care with no possibility of work."

Salmonella, as well as other foodborne bacteria, can trigger reactive arthritis (ReA) in certain individuals. This can cause painful and swollen joints and can greatly a person's ability to work and quality of life.

"In recent years, antibiotic-resistant strains of Salmonella have emerged and their incidence appears to be increasing, particularly in children," says the CDC.

Nearly half of all reported Salmonella cases occur in children.

Another infection that can come from food, Toxoplasma gondii infection, can result in cognitive or visual disabilities, with 80 per cent of infected foetuses or infants emerging as impairment by age 17.

"Impairments from acute foetal or newborn infection by T. gondii can include mild to severe mental retardation, moderate visual impairment, crossed-eyes, and in some cases blindness in one or both eyes," the report says.

The CDC concludes that more research is needed to improve scientific knowledge about the disease.

This will help agencies deal with outbreaks in different populations and parts of the population, particularly among young children.

The CDC has called for epidemiological studies to be able to monitor long term consequences of foodborne illness outbreaks and it adds that follow up studies also should be carried out.

"A new approach is needed to improve our knowledge about the prevalence and scope of foodborne illnesses, as well as the overall burden of foodborne disease," the report says.

"More research is needed to increase our knowledge about the frequency and severity of the long-term health outcomes of foodborne illness, which will, in turn, help identify food safety priorities so that limited resources can be applied appropriately to ensure the greatest public health benefit. State and federal public health agencies charged with the surveillance and oversight of food need stronger research capabilities."

The CDC adds: "Systematic follow-up of foodborne illness cases will greatly enhance our ability to attribute long-term health problems to acute food borne illnesses.

"Population based studies, improved public health surveillance, and increased data sharing will improve our knowledge about the sources, trends, and health outcomes associated with foodborne disease, but sustaining these efforts will require dedicated funding.

"To lower the health, social, and economic burdens of foodborne illness, associated with both its acute impact and its long-term consequences, the United States must support applied foodborne illness research, and begin focusing on the long-term health outcomes associated with foodborne disease."