The Role of AeroCollect in Incubators for Early Aspergillus Detection and Issuance of a “Negative Aspergillus Control” Certificate

 

Dr. Majid Hamid Al-Sayegh

11/ 1/ 2026

Why are incubators a sensitive point for the emergence of aspergillus?

Aspergillus in poultry is one of the most important fungal respiratory diseases, often associated with Aspergillus fumigatus, and is clearly evident in newly hatched chicks during their first few days of life. The danger of this disease lies in the fact that the fungus produces tiny, light spores (conidia) that remain suspended in the air, easily carried by ventilation currents, and then inhaled, reaching deep into the respiratory system. Therefore, incubators—by their very nature—can become an ideal environment for amplifying this risk if conducive conditions are present, such as humidity, heat, organic matter, and the accumulation of down and dust.

During the hatching period, a phenomenon known scientifically as a “sudden increase in aerobic biofilm load” occurs, as down and dust become airborne, and air movement, labor, and transport within sorting and packing areas increase. At this critical juncture, fungal spores—if present in the environment—become more readily dispersed and inhaled, explaining why early losses can occur even in flocks that appear healthy upon arrival. Incubator contamination models have supported the conclusion that environmental samples during hatching (particularly air and down) reflect a surge in microbial pressure within the incubation system.

 

Pathogenesis: What happens inside the chick?

Infection often begins through inhalation. Spores enter the respiratory tract with the air and may settle in the trachea, bronchi, and air sacs. When the exposure dose exceeds the capacity of local defenses to clear the infection (mucus, cilia, phagocytes), the spores begin to germinate and form fungal hyphae, triggering an inflammatory response and ultimately leading to the formation of granulomatous lesions or plaques in the lungs and air sacs. Day-old chicks are more susceptible because:
• Their mucosal and cellular immunity is still immature,
• Environmental exposure in the incubator can be very high over short periods, and
• Post-hatching stress factors (temperature fluctuations, overcrowding, unbalanced ventilation) reduce the efficiency of the early response.

Clinically, panting, respiratory distress, and death may occur within 1–7 days, while post-mortem examination typically reveals nodules or white/yellowish spots on the lungs and air sacs. Recent reviews in poultry confirm that aspergillosis is primarily associated with inhalation of spores from contaminated environments, and that poor ventilation and environmental stress exacerbate the disease.

 

Source of Infection and Transmission Routes in Incubators
It is important to distinguish between the scientific concept of vertical transmission and operational reality. Aspergillosis is not usually a true “vertical” disease from mother to embryo inside the egg, but what can be termed egg-borne contamination may occur: eggshells, egg trays, or incubation equipment become contaminated with spores, which then remain or multiply within the incubator/hatcher environment and are converted into air pressure during hatching. Therefore, the “environment” is the primary driver of infection: incoming air, ventilation systems, filters, condensation, fluff, and dust.

Furthermore, recent discussions about azole resistance of fungi have brought renewed attention to poultry facilities as environments that may harbor fungi of health and veterinary importance, making monitoring environmental fungal load more valuable than relying solely on observing mortality.

The Diagnostic Gap: Why Aren’t Traditional Methods Alone Enough? Some traditional monitoring programs rely on:
• Observing pests in dead chicks,
• Fungal tissue culture,
• or settle plates.

These tools are useful but often too late (after losses have occurred), are not consistently representative (settlement is affected by gravity and air currents), and can be slow compared to the need for rapid management within incubators. This is where the importance of combining classical diagnosis with molecular environmental monitoring comes in, providing an early warning when air pressure begins to rise.

Where Does AeroCollect Come In? Transforming Incubator Air into a Measurable Sample
AeroCollect is used to collect airborne microparticles within incubators, enabling the transformation of air into a sample suitable for molecular analysis (PCR/qPCR). Since Aspergillus spores are among the most important airborne bioparticles in hatchery environments, incorporating AeroCollect into aerodynamic monitoring programs helps monitor spore air pressure within incubators and supports early and systematic decisions regarding hygiene, ventilation, and down and dust management. Published work supports the concept of “airborne surveillance” in poultry using AeroCollect to detect important pathogens such as Campylobacter and Salmonella, reinforcing the operational principle: when the airborne environment is the medium of transmission, air analysis becomes a highly valuable diagnostic tool for early warning and risk management.

Published work supports the concept of “airborne surveillance” in poultry using AeroCollect to detect important pathogens such as Campylobacter and Salmonella, reinforcing the operational principle: when the airborne environment is the medium of transmission, air analysis becomes a highly valuable diagnostic tool for early warning and risk management. A Proposed Practical Program for Incubators (Two-Layer Approach)

To ensure a robust and applicable program, a two-layer approach is recommended:
Layer 1: Routine Aerodynamic Monitoring with AeroCollect (Early Warning) Sampling Points (Fixed):
• Hatcher/Air Exit Area or Center of Hatching Room (where fluff and dust are highest)
• Chick Sorting/Packing Area
• HVAC System (Return and Feed) to monitor filter performance
Timing (Frequent and Clear):
• Before egg insertion (Baseline)
• During peak hatching (highest aerodynamic load)
• After cleaning and disinfection (Check the effectiveness of the procedures)

Analyses:
• qPCR for general detection of Aspergillus (e.g., ITS)
• Qualitative qPCR for A. fumigatus
• Recording results as time points to plot the aerodynamic load trend

Layer Two: Confirmatory Sampling When Suspected or High Load is Present
• Fungal Culture of Down/Dust + Identification
• Examination of Respiratory Suppressions in Cases of Mortality (Dissection/Histology/Cultural Examination)
• Inspection of Moisture Sources: Filters, Ducts, Condensation, Tray Washing and Drying Areas

This approach achieves a crucial balance: rapid early warning of airborne infections and strong evidence through confirmatory diagnosis when needed.

“Aspergillus-Free” Certification: The Correct Scientific Formulation Accepted by Auditing Bodies
From a scientific and regulatory standpoint, no monitoring system can guarantee “100% absence” at all times. Therefore, the strongest professional formulation is a monitoring certificate with negative results within a defined sampling range, timeframe, and plan. This type of certification becomes more reliable when it includes: the sampling locations, dates, type of test, and a “Not Detected Within the Detection Limit” result.

Aspergillus Monitoring in Incubator Certificate (Negative Results): This certificate confirms that on [dates], an environmental monitoring program for the incubator air was implemented at [incubator name/location] using an AeroCollect air sampling device. Laboratory PCR/qPCR tests were then performed to detect Aspergillus spp. and Aspergillus fumigatus according to [methods/protocols]. No Aspergillus targets were detected within the analytical detection limits of the test during the specified sampling points and times. These results support the conclusion that the incubator environment was within the controlled limits for Aspergillus at the time of sampling and constitute official documentation of negative environmental monitoring within the scope of the approved plan. To enhance the acceptance of this certification by clients and regulatory bodies, it is preferable for the analysis to be conducted within a recognized laboratory competency framework, such as ISO/IEC 17025 principles, to ensure the reliability of measurement and documentation.

Added Value: Why will the client consider it a “competitive advantage”?

When you measure the air, you are measuring the factor that actually drives aspergillosis: the air pressure of the spores. This gives incubator management the ability to:
• Detect spikes before mortality occurs,
• Evaluate the effectiveness of cleaning, disinfection, and humidity control,
• Improve ventilation, filtration, and fluff and dust management,
• Issue an official follow-up certificate based on verifiable data.