Gastrointestinal Pathogen Trends

Many respiratory pathogens are seasonal, making their appearance at roughly the same time every year. That’s why late fall through spring has become known as flu season (or, more accurately, respiratory season). When it comes to gastrointestinal pathogens, however, the patterns are not so clear-cut. Some GI bugs seem to be affected by the season—but many do not.

BIOFIRE^® Syndromic Trends (Trend) illustrates the difficulty of pinpointing one yearly “gastrointestinal season.”

A wide array of pathogens can cause gastrointestinal illnesses, including bacteria, viruses, and parasites. Here are a few pathogens that demonstrate the variety of seasonality and transmission trends among these pathogens:

Somewhat Seasonal

Norovirus is a very contagious virus that causes vomiting and diarrhea. Anyone can get infected and sick with norovirus. Some of the possible transmission methods for norovirus are direct contact with an infected person, consuming contaminated food or water, or touching contaminated surfaces and then putting your unwashed hands in your mouth. Norovirus can spread extremely easily; people with norovirus illness can shed billions of norovirus particles—and it only takes a few virus particles to make other people sick.¹

According to the CDC, “Norovirus illnesses and outbreaks are usually more common in cooler winter months. The majority of all outbreaks occur from November to April in countries above the equator, and from May to September in countries below the equator.”² Data from BIOFIRE Trend shows norovirus reaching a peak in March-April for the past two years.

Year-round Spread

Clostridioides (Clostridium) difficile (C. diff) is a bacterium that causes diarrhea and colitis. Anyone can become infected with C. diff, but it’s most commonly acquired by people who’ve recently taken antibiotics or those who’ve been hospitalized or spent time in a nursing home. Additionally, those who’ve already had a C. diff infection are more prone to repeat infections: about one in six patients who get C. diff will get it again in the subsequent 2–8 weeks.³

People over the age of 65 are also at increased risk for C. diff. One in 11 people over the age of 65 diagnosed with a healthcare-associated C. diff infection die within one month.³

Data from BIOFIRE Trend indicates that C. difficile infections remain fairly constant throughout the year.

Setting-related Spread

The highly infectious sapovirus spreads easily in settings where there is close contact between people, including daycare centers, schools, hospitals, nursing homes, and ships. Sapovirus may cause isolated, sporadic cases, or it can cause outbreaks of acute gastroenteritis. While all age groups are affected, children younger than five years of age have the highest burden of disease. Closely related to norovirus, the sapovirus can cause common gastroenteritis symptoms like vomiting and diarrhea, which typically resolve within one week.⁴

Waterborne Transmission

Cryptosporidium is a microscopic parasite that can be spread in several different ways, but water (drinking water and recreational water) is the most common way it spreads. The United States has seen outbreaks of Cryptosporidium in waterparks, community swimming pools, and in daycare centers. Cryptosporidium is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very tolerant to chlorine disinfection—and that’s why it’s a leading cause of waterborne disease among humans in the United States.⁵

Gastrointestinal Infections

Many gastrointestinal pathogens can cause illness—no matter the time of year—but the symptoms are often similar, making it difficult to diagnose a gastrointestinal infection based on symptoms alone.

Traditional stool testing methods are slow, labor intensive, and lack sensitivity. However, syndromic testing with the BIOFIRE^®FILMARRAY^® Gastrointestinal (GI) Panel can help quickly reveal an infectious etiology. The BIOFIRE GI Panel identifies 22 targets associated with gastrointestinal illness, including bacteria, viruses, and parasites, with results in about an hour.

About BIOFIRE Syndromic Trends

BIOFIRE Trend is a software solution that delivers visual insights into the targets detected by BIOFIRE^® FILMARRAY^® Systems. This cloud-based network compiles BIOFIRE^® FILMARRAY^® Panel infectious disease testing results from participating organizations, using that data to deliver local, regional, and global reports.

Participating organizations have access to site-specific trends for the BIOFIRE Panels they use; they can also view data from other BIOFIRE Panels in the regional view. Syndromic testing generates data that can be vital for infectious disease doctors, antimicrobial stewardship committees, infection control committees, and epidemiologists.

Learn more about BIOFIRE Trend and how to join the BIOFIRE Trend network.

References:

CDC. About Norovirus. Accessed 22 Aug 2022. Retrieved from: https://www.cdc.gov/norovirus/about/index.html, accessed 8/22/22
CDC. Norovirus Worldwide. Accessed 23 Aug 2022. Retrieved from: https://www.cdc.gov/norovirus/trends-outbreaks/worldwide.html
CDC. What is C. diff. Accessed 19 Aug 2022. Retrieved from: https://www.cdc.gov/cdiff/what-is.html.
Oka T, et al. Comprehensive review of human sapoviruses. Clin Microbiol Rev 2015; 28: 32–53.
CDC. Parasites – Cryptosporidium. Accessed 19 Aug 2022. Retrieved from: https://www.cdc.gov/parasites/crypto/index.html, accessed 8/19/22