The presence of pets in a home during the prenatal period and during early infancy has been associated with a lower prevalence of allergic sensitization and total IgE levels in middle childhood. No studies have examined the effect of pet exposure in a population-based cohort by using multiple early-life measures of serum total IgE. Effect of prenatal indoor pet exposure on the trajectory of total IgE levels in early childhood. Suzanne Havstad MAa, Corresponding Author Contact Information, E-mail The Corresponding Author, G. Journal of Allergy and Clinical Immunology

Of the food pathogens that cost society the most money — in terms of medical care, lost days of work, long-term chronic health problems or deaths — half are found in poultry, pork, beef and other meat products, according to a study due for release Thursday. Washington Post. Study ranks food pathogens by cost to society. April 2011.

An outbreak of Salmonella associated with multiple locations of restaurant chain A in Phoenix, AZ, was identified in July 2008. Raw chicken, contaminated before arrival at the restaurant, was the apparent source of this outbreak. Poor hygiene likely led to cross-contamination of food and work areas. A prolonged outbreak of Salmonella Montevideo infections associated with multiple locations of a restaurant chain in Phoenix, Arizona, 2008. Patel MK, et al. J Food Prot. 2010 Oct;73(10):1858-63.

Infected employees may have contributed to the spread of illness by inadvertently contaminating foods. Errors in food rotation and inadequate refrigeration on ice-chilled salad bars may have facilitated growth of the S Typhimurium but could not have caused the outbreak. A subsequent criminal investigation revealed that members of a religious commune had deliberately contaminated the salad bars. JAMA. August 6, 1997.

An increasing number of illnesses are international in scope, with contamination in a commercial product occurring in one country and affecting persons in several other countries, or tourists being infected abroad and possibly transmitting the pathogen to others at home. World Health Stat Q. 1997;50(1-2):30-50. Epidemiology of foodborne diseases: a worldwide review. Todd EC.

Food poisoning in humans can be caused by many different bacterial genera. While the incidence of food poisoning in England, Wales and Scotland from Salmonella has reached a plateau, there has been an increase in the incidence from Campylobacter. The E. coli O157:H7 food-borne outbreak in Lanarkshire in 1996 led to 21 fatalities.Symp Ser Soc Appl Microbiol. 2000;(29):144S-148S. Food safety through the meat supply chain. Attenborough M, Matthews KR.

A study was undertaken to determine the microbiological status of surfaces used in the preparation of ready-to-eat foods, and to assess cleaning standards and practices in food premises in the UK. A total of 6,533 environmental samples were examined from 1,502 catering (such as restaurants, cafés, and sandwich bars) or retail premises (such as butchers, delicatessens, and bakers): Cleaning cloths were more heavily contaminated with bacteria (Aerobic Colony Count (ACC), Enterobacteriaceae, E. coli, and Staph. aureus) compared to surfaces sampled. Campylobacter spp. were detected in two (0.2%) and Salmonella spp. from one (0.1%) of the cleaning cloths. Commun Dis Public Health. 2003 Apr;6(1):6-17. Study of cleaning standards and practices in food premises in the United Kingdom. Sagoo SK, Little CL, Griffith CJ, Mitchell RT.

Patients with B. hominis were significantly more likely to have traveled and to have consumed untreated water than controls. Doyle et al. Epidemiology and Pathogenicity of Blastocystis hominis JOURNAL OF CLINICAL MICROBIOLOGY, Jan. 1990, p. 116-121.

US health authorities have recalled some 16,300 tonnes of turkey mince potentially contaminated with multidrug-resistant salmonella. So far one man has died, 107 people are ill with 40% requiring hospilisation. Twenty three have tested positive to the most antibiotic-reistant strain - Salmonella heidelberg. (CDC website. 2011)

E. coli from retail chicken (O25:H4-ST131 and O114:H4-ST117) and honeydew melon (O2:H7-ST95) were indistinguishable from or closely related to E. coli from human UTIs. This study provides strong support for the role of food reservoirs or foodborne transmission in the dissemination of E. coli causing common community-acquired UTIs.Emerg Infect Dis. 2010 Jan;16(1):88-95. Food reservoir for Escherichia coli causing urinary tract infections. Vincent C, Boerlin P, Daignault D, Dozois CM, Dutil L, Galanakis C, Reid-Smith RJ, Tellier PP, Tellis PA, Ziebell K, Manges AR.

The predicted increase of GI patients will significantly intensify the already heavy burden of GI diseases to a level where national healthcare systems of EU Member States may no longer be able to cover the costs. United European Gastroenterology Research (EUG) 2012:

Infection - the risks:

Blasto. is transmitted person to person through the ingestion of cysts in contaminated food or water. Blasto's thick walled cysts have been found in streams and other water sources, including in water which has been chlorinated.

D.fragilis lacks a cyst stage to protect it from the outside environment. Instead the parasite is thought to hitch a ride inside the human pinworm Enterobius vermicularis.

Other sources of infection include farm and zoo animals.

If you are concerned that your dog or cat may be passing on the infection don't be because:

Pets also infer health benefits on humans: A US study recently determined that children whose mothers had an indoor pet during pregnancy have lower levels of Immunoglobulin E, and may be less likely to develop asthma and other allergies. More here.

Unhygienic humans are more of a problem than pets. People who fail to wash their hands after going to the toilet — which is a good number of us according to studies undertaken by the London School of Hygiene & Tropical Medicine. More below.

Coming into contact someone with another's poo is fairly easy, but usually our resident beneficial bacteria protects us against rapid colonisation by bad bugs. However, if Blasto. or D.fragilis are already present in the bowel, but are being kept under control by our beneficial bacteria, then a bacterial infection caught from infected food or water could potentially help Blasto. and D.fragilis to colonise more of the bowel.

Other people's hands:

Studies undertaken by The London School of Hygiene and Tropical Medicine have come up with some alarming statistics:

One in six mobile phones are contaminated with feces. Contamination of mobile phones and hands revealed for Global Handwashing Day. London School of Tropical Hygiene & Medicine. October 2011

Seventy-percent men and fifty percent of women using toilets at UK service-stations failed to wash their hands with soap after using the toilet. Is the person next to you washing their hands with soap? London School of Tropical Hygiene & Medicine. 2009.

A similar study by the School as part of Global Handwashing Day, found that the hands of one in four UK commuters tested positive to bacteria which comes from faeces. In some parts of the UK, up to 60% of commuter's hands tested positive for fecal contamination. Northerners' hands up to three times dirtier than those living in the South. London School of Tropical Medicine & Hygiene. October 2008.


Australian schools are a distribution centre for bacteria and viruses yet school toilets were not required to contain soap." Essential Infection Control. October 2011.

More than half the toilets in primary schools in Wales in the UK were dirty of unacceptable stated Government Inspectors:

Research indicates that school toilets have been identified as areas where certain infections or diseases may be picked up by individuals. This is done in a number of ways – via toilet seats, chain handles, water taps, drinking taps or fountains, soap and other dispensers. These infections include very serious ones such as Hepatitis A and a number of gastrointestinal infections. Where facilities for hand washing and drying are of a poor standard, or not even available, the likelihood of transmission is then extended throughout the school and beyond." Lifting the Lid on the Nation's school toilets. Children's Commissioner for Wales, 2004.

Eating out

In 2010 over 2000 Australian cafes, restaurants and takeaway shops in NSW received fines for hygiene offences (Beware your local eatery. SMH. 2010).

The US and UK have their share of dirty eateries as highlighted in renowned chef Gordon Ramsay's tv show 'Kitchen Nighmares'.

In the US the Toledo-Lucas County Health Department carried out inspections in 70 Ohio restaurants and found enteric bacteria which can indicate fecal contamination. In over 50% of establishments enteric bacteria was found on food contact surfaces, cooler or freezer door handles and on handwashing sink faucets. (Kassa H et al. J Food Prot. 2001.).


Human sewage used to grow food on Australian farms was responsible for a breakout of stomach bugs according to this report in Sydney's Daily Telegraph.

Factory farms are places where farm animals live short, tormented lives. Their waste products contaminates waterways, carrying with it bacteria, viruses and parasites. In 2006 the Bush administration granted factory farms licence to pollute America's waterways. Only thanks to a legal challenge mounted in 2010 against the Environmental Protection Authority (EPA) by environmentally concerned non-profits, factory farm polluters now have to report to the EPA about how they dispose of their manure and other animal waste. Read more

Agricultural runoff is the single largest source of water pollution in the nation’s rivers and streams, according to the Environmental Protection Agency (E.P.A.). An estimated 19.5 million Americans fall ill each year from waterborne parasites, viruses or bacteria, including those stemming from human and animal waste, according to a study published last year in the scientific journal Reviews of Environmental Contamination and Toxicology." The New York Times. 2012

As if polluting America's waterways isn't bad enough, factory farming has created an acid-resistant form of the food-born bacteria E. coli. The stomach of grain fed cows is highly acidic and scientists have found that E. coli from grain fed cattle has evolved to become resistant to strong acids. Stomach acid acts as a barrier to ill health by killing the bugs before they reach the intestine. This means that new breed of E.coli can now easily travel into the intestine. Some strains of E. coli are pathogens that cause intestinal infections. Two percent of E.coli harboured by grain fed cattle is E.coli 0157 - a strain which has caused the deaths of children. E. coli, just like the cysts of Blasto., can survive in and spread through water.

How food is produced:

Salads, fruit and fruit juice:

In 2004 The Foodborne and Diarrheal Diseases Branch of the CDC warned that eating uncooked fruit, vegetable, salad, or juice is not risk free. Foods most often implicated in data analysed between 1973 to 1997 by the Foodborne Outbreak Surveillance System were: salad, lettuce, juice, melon, sprouts, and berries. In the US these foods were associated with 16,058 illnesses, 598 hospitalizations, and eight deaths. (J Food Prot. 2004).

Two-hundred and eight samples of bagged lettuce purchased in Connecticut and New York tested positive to fecal coliform bacteria - with some samples testing positive to extremely high levels of fecal contamination. (March 2010 Consumer Reports Magazine.)

Between 1995 and 2005 orange juice, apple juice and other types of fruit juice were implicated in more than a thousand outbreaks of illness reported to the Centre for Disease Control. Some of the disease causing bugs identified were Salmonella, cryptosporidium and two potentially deadly strains of E.coli. Despite these outbreaks, some juice operations are exempt from processing requirements or do not comply with food regulations. They continue to be implicated in outbreaks of illness. (J Food Prot. 2008 Feb;71(2):356-64.)

Forty-eight percent of samples taken from beverages served at US soda fountains were positive for coliform bacteria. Coliforms are an indication of poor sanitation and fecal contamination. More than 11% contained Escherichia coli and over 17% contained Chryseobacterium meningosepticum - a bug associated with a 57% mortality rate. (Medicine (Baltimore) 1997). Other nasties included Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia, all bacteria which proved to be resistant to one or more of 11 antibiotics tested. (International Journal of Food Microbiology 31 January 2010).

Travel & holidays

Travel to exotic locales and countries where parasites are endemic obviously will increase the risk of exposure to bugs such as Blasto. and D.fragilis, but it's not necessary to leave the country to become infected.

Blasto. can be caught from swimming pool or lake water because Blasto's thick walled cysts can survive in water, including in water which has been chlorinated.

Bore, well and tank water pose a risk for becoming infected: A number of people over the years have tested positive after drinking well or tank water whilst holidaying at a place where drinking water was collected.

People who regularly drink from these sources but have never fallen ill often convince others it's safe to do so. A camper contacted me because she had fallen ill soon after drinking from a stream whilst on a hike in the US wilderness. Another seasoned hiker convinced both her and the woman's hiking buddy that the water was safe to drink. She fell ill with GI and systemic symptoms and tested positive to Blasto. Her friend, who drank from the same stream, had no symptoms and wasn't tested.


Steps to avoid infection or reinfection:

Heating or cooking food is the best way to inactivate food-borne pathogens. Peel fruit or wash thoroughly in soapy water before eating.

Pregnant women should ensure that their food is obtained from reputable establishments; stored, handled, and cooked properly; and consumed within a couple of days of purchasing. Can Fam Physician. 2010 Apr;56(4):341-3. Food-borne illnesses during pregnancy: prevention and treatment. Tam C, Erebara A, Einarson A.

Wash hands well in soapy hot water before preparing food, before eating, and of course after using the toilet.

The Australian Food Authority's Scores on Doors program is a step forward for customers - but it doesn't go far enough. Restaurants, cafes and other food outlets are not compelled to display a ratings certificate. More about the scheme here

This excellent blog about food safety, or rather lack of it, is maintained by Professor Douglas Powell, Food Safety Dept at Kansas State University.

CDC Website: Food-Related Illness and Death in the United States & Handwashing: Clean Hands Save Lives..