IV tubing contamination probe echoes a decades-long pattern of infusion-related outbreaks

The Centers for Disease Control and Prevention says it has been notified of reports of black specks, discoloration, or other particulate matter inside the drip chambers of intravenous (IV) tubing, the plastic sets that carry fluid from a bag into a patient's vein. The tubing comes from a single manufacturer, ICU Medical, and the problem has turned up across numerous lots and three separate product types, according to Maine's health department. In some sets the specks appear inside the actual channel the fluid passes through; in most, they are embedded in the plastic itself rather than in the fluid path.

As of the CDC's most recent notice, no patient infections or adverse events have been linked to the contaminated tubing. Maine's investigation, which began earlier, says preliminary reports from at least one other state suggest the issue may extend across a nationally distributed product line rather than being confined to a single facility or region. ICU Medical and the FDA have both issued notices telling health facilities what to do: inspect tubing before use, set aside anything with visible anomalies, and report it either to the manufacturer or through the FDA's MedWatch adverse-event system.

Investigators studying infusion contamination generally sort it into two categories. Intrinsic contamination happens during manufacturing, before the product ever reaches a hospital. Extrinsic contamination happens afterward, during shipping, storage, or when staff prepare and administer the fluid at the bedside. A scoping review of outbreaks in low- and middle-income countries found that of 59 contaminated IV fluids and medicines identified across 50 published outbreak reports since 1975, a third had been contaminated intrinsically, during manufacture, rather than in the hospital.

The same review found that just over half of the contaminated products, excluding nutrition fluids, had been used incorrectly as if they were multi-dose vials, meant to be drawn from repeatedly, when they were designed as single-dose vials meant for one use only. Single-dose vials contain no preserving chemicals to hold back bacterial growth once opened, unlike multi-dose vials, which do. Most patients affected across these outbreaks were children, and the review reported a median case fatality ratio of 21.1%, ranging as high as 87.5% in some outbreaks, among the reported incidents. The bacteria most often responsible belonged to groups called Enterobacterales and non-fermentative Gram-negative bacteria, which together made up about 94% of the isolated organisms.

Infusion-related outbreaks are not new. In a 1971 investigation, the CDC and FDA linked 150 cases of bloodstream infection, and nine deaths, across eight U.S. hospitals in seven states to IV fluid bottles made by Abbott Laboratories, then the source of about 45% of all IV fluid sold in the country. The organisms involved, Enterobacter cloacae and bacteria from the Erwinia group, were unusual causes of bloodstream infection at the time, which helped investigators recognize the pattern.

CDC testing eventually found that the bacteria could survive on the plastic liner inside the bottle caps, and that simply unscrewing a cap, adding medication, and screwing it back on could transfer the organisms into the fluid. The agency isolated the outbreak strains directly from 13 of 1,825 sampled one-liter bottles it later tested. The response at the time included telling hospitals to open containers only right before use, never replace a cap once removed, and change all IV tubing daily. A 1997 editorial note on the case observed that the investigation could not identify a specific defect in how hospitals were managing the IV systems, which pointed investigators toward the manufacturing process itself.

Contamination can also enter through ingredients sourced for pharmacies to mix into injectable drugs, a process called compounding. In 2019, the FDA reported that seven patients at an outpatient clinic developed symptoms including nausea, vomiting, chills, and low blood pressure within minutes of receiving an intravenous injection containing L-glutathione, a substance compounded by a pharmacy using powder repackaged by a company called Letco Medical. One patient developed low blood pressure and breathing difficulty and was hospitalized; a patient from a separate, unrelated case involving the same repackaged powder developed fever and shaking and was admitted for a suspected bloodstream infection.

FDA testing found the powder contained excessive levels of bacterial endotoxin, a substance that can cause reactions ranging from fever to death when it enters the bloodstream, with some samples measuring as much as five times the limit the agency calculated as appropriate for the doses patients had received. The powder had been labeled by its manufacturer for use only in dietary supplements, not for sterile injectable drugs, and the manufacturer's own invoice noted it was not intended for pharmaceutical use. The FDA said that information had not carried through clearly onto the paperwork the compounding pharmacies received, and it urged manufacturers and repackagers to label such ingredients more clearly.

The current investigation into ICU Medical's tubing remains open, and health authorities have stressed that, unlike the 1971 and 2019 cases, no infections or adverse events have so far been tied to the black specks and discoloration reported in the drip chambers. Maine's health department has described the scope as still being determined, based on preliminary reports from more than one state. The scoping review of outbreaks in lower-income countries also flagged gaps that go beyond any single incident, including limited hospital access to properly formulated pediatric IV products and a shortage of published research from lower-income countries generally, which its authors said likely means such contamination events are underreported worldwide.