A study in China provided estimates of the incidence of five pathogens, with norovirus at the top.
By examining rates across gender and age groups, scientists can identify priority populations for targeted preventive interventions aimed at reducing the burden of disease. These insights help develop public health policies and manage food safety risks.
The traditional passive surveillance system often misses specific pathogens and is plagued by underreporting and underdiagnosis, which complicates understanding the burden of disease. However, a study published in China CDC Weekly found that the creation of a laboratory-based foodborne disease surveillance platform in 2011 improved disease tracking.
The study developed a pyramid model to estimate the incidence of five pathogens. The model takes into account steps such as patients seeking care, hospitals collecting stool samples, laboratories analyzing these samples and the subsequent identification of pathogens.
Incidence by age and gender
Scientists merged data from hospital surveillance and previous community surveys in China with census data to estimate the incidence of diarrheal diseases. Pathogens included Salmonella, Vibrio parahaemolyticus, Shigella, diarrheagenic E. coli (DEC), and norovirus.
The prevalence of infection by five pathogens varied significantly between genders, with men showing a higher overall prevalence. Salmonella, DEC and norovirus were more common in men than in women. In contrast, Vibrio parahaemolyticus was more common in women.
Southern China had the highest prevalence of these pathogens, while Northeast China had the lowest.
Norovirus showed the highest incidence and mainly affects children between the ages of 1 and 4 years. However, only a fraction of these cases are attributable to transmission via food. Salmonella was most common in infants under 1 year of age, followed by the 1 to 4 year age group.
The highest incidence of Vibrio parahaemolyticus was among people aged 35 to 44, likely due to a preference for raw or undercooked seafood, including shellfish, scientists said. DEC was most common in the 20 to 24 year old group. Shigella had the lowest incidence, with the highest rates among children aged 5 to 9 years.
“This study provides the first estimates of the incidence of five pathogens by age and sex derived from active surveillance data on foodborne illness in China. These findings serve as a critical basis for informed decision-making and regulation when assessing food safety risks based on disease burden,” researchers said.
Mushroom poisoning
In another outbreak report, four patients in Yunnan province were affected by Cordierites frondosus poisoning in two incidents. Cordierites frondosus is a type of poisonous mushroom.
The condition of two patients worsened after they were re-exposed to sunlight on the seventh day after the initial poisoning. In the other incident, two patients reported a mild, needle-like sensation on areas of their skin exposed to the sun on the twelfth day after poisoning.
Scientists said it is advisable to avoid sunlight for at least two weeks after poisoning.
In May and June 2023, four cases of suspected mushroom poisoning were treated in a hospital: patients developed photosensitive dermatitis 21 to 45 hours after ingesting wild wood ear mushrooms. The Chinese CDC worked with the local hospital to investigate.
Findings suggest that poisonings were caused by the consumption of cordierite leaves, a wild mushroom species similar to the traditionally edible Auricularia fungi.
Symptoms of photosensitive dermatitis include redness, swelling, itching, blistering, and sharp pain in the face and hands. These symptoms are increased by exposure to sunlight.
The four patients were three men and one woman, aged 45 to 57 years. Two patients had gastrointestinal complaints three hours after consuming mushrooms. The development of photosensitive dermatitis in all patients occurred 21 to 45 hours after consuming 30 to 50 grams of mushrooms.
Local officials have posted signs in villages with information about poisonous mushrooms native to Yunnan. The signs are intended to educate residents on identifying poisonous mushrooms and understanding the risks of mushroom poisoning. Since this action was taken, no other cases of similar poisoning have been reported.
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