Investigations of the Distribution and Persistence of Salmonella and Ciprofloxacin‐Resistant Escherichia coli in Turkey Hatcheries in the UK

This study aimed at gaining information on the presence of Salmonella in UK turkey hatcheries and possible epidemiological links between breeding farms, hatcheries and finishing farms. The presence of ciprofloxacin‐resistant E. coli in hatchery samples, as well as in faecal samples from farms, and trends in occurrence of resistance were also investigated. Over a 2 year‐period, four British turkey hatcheries were visited and intensively sampled for the presence of Salmonella and ciprofloxacin‐resistant E. coli. In two hatcheries, a link could be demonstrated between the presence of certain Salmonella serovars in the hatcheries and on breeding and finishing farms. Within the hatcheries, serovars linked to breeding farms were found more frequently in the poult processing and dispatch areas, whereas serovars identified as ‘resident hatchery contaminants’ were predominantly found inside the hatcher cabinets. Ciprofloxacin‐resistant isolates of S. Senftenberg were identified in one hatchery, which coincided with enrofloxacin treatment of some of the breeding flocks. Ciprofloxacin‐resistant E. coli was found in two hatcheries, and the majority of these isolates showed multidrug resistance.     

Prevalence of Clostridium perfringens in commercial broiler hatcheries.

Clostridium perfringens, a cause of human foodborne and poultry disease, has been isolated from the intestinal tract of poultry and from the processed carcass. Little is known about the incidence and sources of this pathogen in the poultry production environment. To determine if the broiler hatchery is a possible source of C. perfringens, we collected samples from three hatcheries, each operated by a different poultry integrator, and the presence of C. perfringens in these samples was determined. For each sampling period, eggshell fragments, chick fluff from the hatcher, and paper pads stored in the hatchery before use with chicks and after placement beneath chicks for 1 hr were evaluated. Clostridium perfringens was found in eggshell fragments, fluff, and paper pads in each of the three hatcheries. The percentages of C. perfringens-positive samples from the three hatcheries ranged from 13% to 23%, with an overall incidence of 20%. Positive samples were consistently found, i.e., detected on each of the nine sampling days (three sampling days for each of three hatcheries). These results suggest that the hatchery is a potential source/reservoir for C. perfringens in the integrated poultry operation.     

A temporal study of Salmonella serovars from environmental samples from poultry breeder flocks in Ontario between 1998 and 2008

A temporal study was carried out to determine Salmonella prevalence, trends, major serovars, and their clusters from environmental samples, in poultry breeder flocks in Ontario between January 1998 and December 2008. Surveillance data were obtained from the Ontario Hatchery and Supply Flock Policy. Logistic regression with a random effect for flock was used to identify factors [poultry type, year (trend) and season] associated with the prevalence of Salmonella. A cluster detection test was used to identify clusters of common serovars. The period prevalence of Salmonella was 47.4% in broiler-breeder, 25.7% in layer-breeder, and 19.6% in turkey-breeder flocks. The overall trend in the prevalence of Salmonella was decreasing for all breeder types, due primarily to decreasing trends of Salmonella Heidelberg. The seasonal effects varied by year with the highest probability of Salmonella occurring in different seasons. The 4 most common serovars identified were Salmonella Heidelberg, Kentucky, Hadar, and Typhimurium in broiler-breeders; Salmonella Heidelberg, Brandenburg, Thompson, and Typhimurium in layer-breeders; and Salmonella Heidelberg, Saintpaul, Brandenburg, and Muenster in turkey-breeders. Salmonella Enteritidis was infrequently isolated in all poultry breeder types. Temporal clusters of different serovars were identified in all poultry breeder types. Clusters of Salmonella Heidelberg, Typhimurium, and Hadar from environmental samples from breeder flocks were detected during a similar period to clusters from hatchery fluff samples from the same population. Therefore, interventions at the breeder flock-level might help to reduce transmission of Salmonella from breeder flocks to hatcheries and possibly, to lower levels of the poultry production chain.     

Risk Factors Associated with Detection of Salmonella in Broiler Litter at the Time of New Flock Placement

In this study, we investigated risk factors associated with the probability to detect Salmonella in samples of litter collected within 2 h prior to new flock placement in 76 grow‐out houses on 38 conventional broiler farms located in the US states of Mississippi, Alabama and Texas. We evaluated characteristics of location and layout of the farm; area adjacent to and surrounding the house; house construction; condition and type of equipment in the house; litter management and other production, sanitation, visitation and biosecurity practices; non‐broiler animal species on the farm; and weather conditions on the 3 days leading up to flock placement. Logistic regression was used to model the relationships between probability to detect Salmonella in litter and potential risk factors. In the screening process, each risk factor was evaluated as a single fixed effects factor in a multilevel model that accounted for variability among the sampled farms and their production complexes and companies. Of almost 370 risk factors screened, 24 were associated with the probability to detect Salmonella in litter. These were characteristics of the surroundings of the house, house construction and conditions, litter management, length of downtimes between flocks in the house, biosecurity and farm location. After investigation of collinearity between these variables and building of models for important risk factor categories, the list of candidate variables for the final model was refined to eight factors. The final model demonstrated that a higher probability of detecting Salmonella in litter was strongly associated with the use of wood to construct the base of the walls or to cover the inside of the broiler house foundation, and with the use of fresh wood shavings to top‐dress or completely replace the litter between flocks.     

On-farm risk factors for Salmonella Enteritidis contamination

Forty layer farms from 2 states participated in a study to examine the risk factors and incidence of Salmonella Enteritidis from multiple samples, including environmental drag swabs from the bird areas, feed, water, flies, rodents, live rodent traps, and environmental swabs from areas occupied by other livestock. Twenty-four of these farms had between 3,000 and 31,000 bird flocks (medium-sized flocks) and 16 had less than 3,000 birds (small-sized flocks). All were housed in cage-free production systems. Twenty-two farms included outside pasture areas for the birds. Most of the participants had just come under the FDA Egg Rule and had not yet tested their flocks (flocks under 3,000 birds are exempt) for Salmonella Enteritidis. Many, however, obtained their pullets from commercial Salmonella Enteritidis-clean breeder sources hatched in National Poultry Improvement Plan hatcheries. Vaccination against Salmonella Enteritidis was performed on 21 of the 40 farms (combination of live and killed vaccines). Salmonella Enteritidis was detected on 7 out of the 40 farms, primarily in rodents, their feces, or from swabs taken inside live traps. Of these 7 Salmonella Enteritidis-positive farms, 3 farms that had vaccinated their pullets with live Salmonella Typhimurium vaccine and killed-Salmonella Enteritidis vaccine; no Salmonella Enteritidis was isolated from the environmental drag swabs taken from the bird area or from the eggs on these farms. However, on the farms that had not vaccinated for Salmonella Enteritidis, the organism was isolated from 4 environmental drag swabs and 3 egg pools. The last 4 farms had flocks under 3,000 birds. No Salmonella Enteritidis was isolated from any of the samples of feed, flies, water, or swabs taken from other livestock areas. Based on the initial findings in this study, we suggest the 2 most important risk factors for Salmonella Enteritidis contamination inside the bird area and in the eggs in these small- and medium-sized flocks are the presence of infected rodents and the absence of an Salmonella Enteritidis vaccination program.     

Hatchery hygiene evaluation as measured by microbiological examination of samples of fluff

The microbial content of 1,180 samples of fluff from hatchers at 18 chick and 6 turkey hatcheries has been determined. The samples were taken (a) 12–15 hr before removal of birds from the hatchers, (b) just before or after theremoval of chicks orpoults, (c) after fumigation and (d) inreplicate from the same hatcher.

Fifty‐eight per cent of the samples of chick fluff contained one million or more bacteria but only 24 per cent contained more than 100,000 coli‐aerogenes bacteria. Moulds were not found in 68 per cent of the samples. Some samples of fluff were examined for coagulase positive staphylococci and fluorescent pseudomonads but these organisms were generally not detected. Bacillus cereus was recovered in very large numbers from a few samples. Bacterial and coli‐aerogenes counts from poult fluff were generally higher than those from chick fluff but the numbers of pseudomonads and coagulase positive staphylococci recovered were generally negligible.

In an intensive study of samples of fluff from one turkey hatchery, it was found that the level of contamination of fluff increased during hatching and the laying season and was accompanied by a decrease in poult quality. Sampling from any location in the hatcher appears to provide a representative indication of overall contamination at that time. Fumigation of fluff and debris generally caused a reduction in the level of contamination in the fluff.

A suggested assessment of hatchery hygiene based on the microbial examination of fluff is given and the advantages and disadvantages of this method are discussed.     

Serotype and genotype diversity and hatchery transmission of Campylobacter jejuni in commercial poultry flocks.

We investigated the genotype and serotype diversity of Campylobacter coli and C. jejuni in two parent flocks of adult hens and their offspring over two rotations in order to evaluate the role of hatchery mediated transmission and/or vertical transmission of campylobacters in broiler flocks. In total, 314 C. jejuni and 32 C. coli isolates from parent and broiler flocks and from the surroundings of broiler houses were typed by flagellin gene PCR/RFLP (fla-typing), and selected isolates were also typed by serotyping and macrorestriction profiling using PFGE (MRP/PFGE). The combined typing results showed that the broiler flocks could be colonised by 1-3 different Campylobacter clones and parent flocks could be colonised by 2-6 different clones. C. coli was isolated from up to 36% of birds in one parent flock, whereas only C. jejuni was isolated from broiler flocks. C. jejuni clones from different flocks were clearly discriminated by fla-typing as well as by MRP/PFGE, except for a few cases where individual isolates belonging to two different clones were found to have altered fla-types. Similarly, one C. coli clone showed pronounced fla-type variation. The present results lead to the conclusion that vertical transmission or horizontal transmission via the hatchery are not significant transmission routes of C. jejuni to broiler chickens under Danish conditions. In the cases where more than one Campylobacter clone simultaneously colonised flocks, we found that the different clones coexisted in flocks rather than excluding each other.     

Risk factors for Salmonella enterica subsp. enterica contamination in French broiler-chicken flocks at the end of the rearing period

Broiler-chicken are often Salmonella carriers. However, these bacteria are responsible for major food-borne human infection, in which poultry-meat products are frequently implicated. In order to prevent Salmonella spread during the slaughtering process, control measures should be implemented at the farm level to reduce the prevalence before slaughtering. The objective of this study was to identify the risk factors for Salmonella contamination in French commercial broiler flocks at the end of the rearing period. A prospective study was carried out in 1996 and 1997 on 86 broiler flocks located in western France. The Salmonella status of the flocks was assessed by means of litter swabs and dust samples analyzed with classical bacteriological methods. Sixty flocks (70%) had at least one contaminated environmental sample and were classified as Salmonella-contaminated flocks. Logistic regression was used to assess association of managerial practices, general hygiene and results of environmental Salmonella recovery, with the odds that the flock itself would be Salmonella-contaminated at the end of the rearing period. Salmonella contamination of the house before placing day-old chicks and the Salmonella contamination of day-old chicks were significantly related to Salmonella contamination of the flock at the end of the rearing period. The risk for Salmonella contamination of the flock was increased when feed trucks parked near the entrance of the change room and when feed meal, instead of small pellets, was provided at the start.     

Changes in eggshell structure and predisposition of broilers to health problems: is there a common pathophysiology?

1. A study of broiler breeder eggs differing in eggshell matrix optical density was conducted to determine the association of eggshell structural quality and the risk of disease in broilers.

2. A total of 10 000 eggs from a broiler breeder flock were examined according to the pre-established criteria, and allocated to groups classified as having a high or low density shell matrix.

3. The eggs from respective groups were incubated and hatched in a commercial hatchery. Samples of unhatched eggs from each group were subjected to detailed examination to establish the cause of reproductive failure. First, quality chicks from each group were raised as separate flocks in a commercial broiler barn. Group performance, morbidity, and mortality were monitored throughout the growth period. All birds were processed in a commercial plant, and condemnation data were compiled.

4. There were significantly more unhatched eggs, and fewer quality chicks in the group classified as having a low density eggshell matrix, in comparison to the high-density group.

5. Embryo pathology accounted for a large proportion of the overall reproductive failure in both groups, with a large proportion of embryos showing anatomical anomalies. The eggs and embryos from the low-density eggshell matrix group were three times more likely to be infected.

6. Significantly higher production losses associated with mortality/morbidity, and condemnations of carcasses at processing were observed in broilers from the low-density eggshell group compared with the high-density eggshell group.

7. It is concluded that common metabolic/physiological changes in breeder hens associated with eggshell pathology may be also risk factors linked with predisposition of broiler chicks to some health problems.

     

Faecal Sampling Underestimates the Actual Prevalence of Salmonella in Laying Hen Flocks

Summary In all European Union member states, Salmonella monitoring in poultry flocks is obligatory. In these monitoring programmes, a limited number of pooled faeces and/or dust samples are collected to determine whether Salmonella is present in the flocks or not. Whether these limited sampling protocols are sufficiently sensitive to detect expected low within‐flock prevalences of an intermittently shed pathogen is not yet clear. In this study, a comparison is made between different sampling procedures for the assessment of the between‐ and within‐flock prevalence of Salmonella in laying hens. In total, 19 farms were sampled. Using a comparable sampling methodology as in the official surveillance programmes, Salmonella could not be detected in any of the flocks. After transportation of the hens to the laboratory and subsequent analysis of cloacal swabs and caecal contents, Salmonella Enteritidis was detected in laying hens from five of 19 farms. The observed within‐flock prevalence ranged from 1% to 14%. Based on the results of this study, it can be expected that, depending on the sampling procedure, different estimates of the prevalence of Salmonella can be obtained and the proportion of Salmonella infected flocks is underestimated based on the results of the official monitoring programme.     

Evaluation of Salmonella serotype distributions from commercial broiler hatcheries and grower houses

By conventional trayliner (hatcheries) and drag swab assembly (broiler houses) culture methods, the isolation distribution of Salmonella serotypes from five commercial broiler hatcheries (three sample times) and 13 broiler farms (eight sample times) was evaluated. A total of 11 different Salmonella serotypes were isolated from hatcheries, with Salmonella heidelberg (9/30) and Salmonella kentucky (6/30) accounting for 50% of the total isolations. Of 700 chick paperpad trayliners sampled, regardless of lot (breeder flock source) or hatchery, 12% were positive for Salmonella. When 10 individual trayliners were cultured from individual lots (same breeder flock source), Salmonella was detected in 24/57 lots (42%). Multiple serotypes were simultaneously isolated from the same lot on three occasions (6%). Of the 21 lots that were serially sampled, the Salmonella serotype detected was different within lots eight times (38%) on at least one occasion of two or more sampling times. Of the 196 individual broiler houses sampled, 44 were positive for Salmonella (42%). Twelve different serotypes were isolated from broiler houses during this study. The serotypes isolated most frequently were S. heidelberg (34/94) and S. kentucky (22/94). These two serotypes accounted for 59.6% (56/94) of the total broiler house isolations. Of the 38 houses that were serially sampled, two or more serotypes were detected in the same broiler house on 20 occasions (53%). Of the 38 serially sampled houses (four or more times), a consistent Salmonella serotype was detected in five houses (13%). In only 5 of the 38 (13%) serially sampled houses did we fail to detect Salmonella on four or more samplings. No significant difference in Salmonella isolation frequency was observed between poultry houses using new or used litter. These data support previous findings indicating that paratyphoid Salmonella serotypes are prevalent in some broiler hatcheries and houses. Further, the observation of multiple serotypes simultaneously and serially isolated from the same breeder hatchery lots suggests that breeder flocks may be infected with more than one serotype, possibly providing a source for multiple serotype infections in progeny grower flocks.     

Epidemiological associations between characteristics of registered broiler chicken flocks in Canada and the Salmonella culture status of floor litter and drinking water

A Canada-wide flock management survey of 294 randomly selected commercial broiler chicken flocks was conducted during 1989-1990. The prevalence of flocks that yielded Salmonella from cultures of floor litter or drinking water, and the prevalence of floor litter samples that yielded Salmonella, were significantly associated (p < 0.05) with the age of the flock and the region of Canda in which the flock was located. Culture of Salmonella from the drinking water was significantly associated (p < 0.05) with the type of drinker used, the dead bird disposal method, and the region of Canada in which the flock was located. There was a significantly greater risk (p < 0.05) of contamination of drinking water with Salmonella from trough drinkers (odds ratio = 7.99) and plastic bell drinkers (odds ratio = 6.10) than from nipple drinkers. No significant associations were found between pest control, restrictions on visitors, clean-out methods, or water sanitization and the culture of salmonellae from floor litter or drinking water.     

The horizontal transfer of Salmonella between the lesser mealworm (Alphitobius diaperinus) and poultry manure

There is need to determine the nature of enduring reservoirs of Salmonella contributing to perpetual contamination within poultry flocks. The dispersal of Salmonella between birds, litter and the lesser mealworm has been established, but the extent that these act as critical components in the epidemiology of Salmonella infection during broiler grow‐out and flock rotation has not been delineated; in particular, the level of participation by the lesser mealworm beetles (LMB) as agents of retention and dispersal. This study defines this route of transmission and provides empirical data on bacterial loads that facilitate Salmonella transfer. Results showed differential Salmonella transfer dependent on bacterial concentration. At 10³ cfu/ml, only a small, but not significant, amount of Salmonella was transferred, from the LMB to the manure and back to uninfected LMB; while from 10⁵ to 10⁷ cfu/ml, a significant acquisition and transfer occurred both internally and externally to the LMB over 4 and 24 hr exposures. These data will be used in correlation with facility management practices to develop intervention strategies to mitigate the establishment and spreading of reservoir Salmonella populations contributing to pre‐harvest contamination of poultry flocks.     

Comparison of Staphylococcus aureus recovered from personnel in a poultry hatchery and in broiler parent farms with those isolated from skeletal disease in broilers.

Personnel from one broiler hatchery, and workers on 18 separate broiler parent farms which supply the hatchery, were tested for hand and nasal carriage of Staphylococcus aureus. In both locations, nasal carriage of S. aureus was more common than hand carriage. A total of 63 S. aureus strains were characterised by biotyping, protein A analysis and pulsed field gel electrophoresis (PFGE) typing. Of these, 36 were recovered from broiler hatchery personnel, 14 from broiler parent farm personnel and 13 from cases of skeletal disease in commercial broilers. Biotyping and protein A analysis indicated that none of the strains recovered from hatchery personnel were of the poultry biotype, but that two strains recovered from the hands of two broiler parent farm personnel could be grouped together with 12/13 of strains recovered from skeletal disease in broilers, as poultry biotypes. PFGE-typing could not distinguish 9/13 strains recovered from skeletal disease in broilers and one of the strains from the broiler parent farm personnel from isolate 24 (I. 24), which is the predominant S. aureus strain type associated with clinical disease in N. Ireland broiler flocks. The present study found no evidence of nasal carriage of S. aureus strains of poultry biotype by humans. The finding of hand carriage by broiler parent farm personnel, suggests that handling by personnel may contribute to the dissemination of I. 24 or other S. aureus strains associated with skeletal disease in broilers.     

SOME HATCHERY FACTORS INVOLVED IN EARLY CHICK MORTALITY

Observations made in a commerical broiler hatchery revealed that chicks hatched over a period of 48 hours. Chick mortality to 10 days of age was 3.2% for those hatched at the commencement of the hatch, 1.2% for those hatched at peak of hatch and 52.9% for those hatched at the end of hatching. Chicks hatched early were more prone to dehydration while late hatching chicks had a higher incidence of leg weakness. Chicks held for 48 hours in hatcher machines lost 12.5% to 21.7% of their hatching weight and 79.4% of the hatching weight of the yolk sac. Normal 10-day mortality from this hatchery in winter months was observed to be 2.4% but was reduced to 1.2% when staggered setting times of donor flocks was employed by removing chicks from the machines 3 hours after 100% hatch, but was increased to 5.6% by holding chicks in the hatchery in chick boxes for 24 hours at 70 degrees C.     

Some factors affecting downgrading in eggs,especially damage in transit

From data collected over the course of a year in a commercial broiler hatchery it was possible to infer the positions in the boxes that had been occupied during transit from farm to hatchery by 25,179 eggs subsequently downgraded upon candling. Two thousand seven hundred eggs were sampled from each of 168 consignments; the total number of eggs sampled was nearly half a million. They came from flocks of two strains and were candled by four candlers. Analysis of variance showed the downgrading rate to depend on (a) identity of the candler, (b) strain, (c) sample, which was confounded with flock and season, and (d) position of the egg in the box. Positional variation occurred in all three dimensions. Vertically (between trays) the downgrading showed a linear increase from top to bottom. Horizontally (within trays) the variation was such that eggs near the corners were at greatest risk, followed by those in the middle of the sides. Those in the centre of the tray were at least risk. The horizontal variation is believed to be due to damage caused by unidentified external objects (at the corners) and by the string with which the boxes were tied (at the middle of the sides). Within‐box variation accounted for the downgrading of 1 egg in 200. There is a need for further work on the design of egg trays and boxes.     

Therapeutic use of enilconazole in broiler chicks with aspergillosis

The course of a spontaneous outbreak of aspergillosis in a broiler flock was studied. Up to the 10th day of life the total mortality was 8%. Surviving broiler had an average body weight of 141 g on the 7th day of life, in contrast to the normal body weight of 150 g per bird. Aspergillosis was diagnosed in another three broiler flocks as well in an early stage of infection. Treatment with Enilconazole (Clinafarm Spray, Janssen, Neuss) in these flocks at a single time via spray in a dosage of 1.5 g enilconazole per 10 m2 housing ground obviously reduced mortality from the second day on after treatment. The average body weight of 7-day-old broiler was in a normal range. The success of the treatment depends on an early diagnosis and immediate start of the therapy. The source of infection (hatchery, transport, litter etc.) should be discovered and eliminated to prevent flocks from further infections.     

Assessing evidence of a potential Salmonella transmission across the poultry food chain

Enhanced Salmonella surveillance programmes in poultry were implemented in all European Member States, with minimum prevalence targets for a list of targeted serotypes to safeguard food and public health. Based on the Belgian Salmonella surveillance programme and focusing on poultry, the overarching aim of this study was to highlight possible Salmonella transmissions across the food chain (FC). For this purpose, firstly, the prevalence patterns of Salmonella (targeted and the most prevalent non-targeted) serotypes along the FC were described over time. Secondly, the effectiveness of the control measures against vertical transmission (breeders to 1-day-old broiler and layer chicks) was indirectly assessed by looking into the odds of targeted serotypes detection. Thirdly, it was appraised if Salmonella prevalence can significantly increase during broilers and layers production. In addition, it was tested if being tested negative at the end of production in broilers when tested positive at the entrance is serotype dependent (targeted vs. non-targeted serotypes). Results showed that, firstly, the prevalence patterns of the listed serotypes were inconstant over time and across the FC. Secondly, the odds of Salmonella targeted serotype detection in 1-day-old broiler and in 1-day-old layer flocks were lower than in breeder flocks while, thirdly, infection during broiler and layer production can lead to significant increase in positivity in subsequent samples. Finally, being infected by a targeted or by non-targeted serotype at the entrance of the flock poorly reflects the Salmonella status at the end of production. Note that this study did not make a distinction between the different sources of contamination and the effects of sampling methods and isolation methods should be subject to further investigation.     

Identification and selection of food safety‐related risk factors to be included in the Canadian Food Inspection Agency’s Establishment‐based Risk Assessment model for Hatcheries

Towards the continuous improvement of its inspection system, the Canadian Food Inspection Agency (CFIA) is developing an Establishment‐based Risk Assessment model for Hatcheries to allocate inspection resources based on the food safety risk associated with the Canadian hatcheries falling under its jurisdiction. The objectives of the current study were to identify and select critical food safety‐related risk factors that would be included in this model, with a main focus on Salmonella. A literature review was used to develop a comprehensive list of risk factors that could potentially contribute to the food safety risk attributed to Canadian hatcheries operating in all production streams (breeders, layers, broilers, turkeys, waterfowl and game birds). The development of this list used a selection process that was conducted according to the availability of data sources, the clarity of definition and the measurability of the selected risk factors. A panel of experts reviewed and adjusted the identified risk factors. A final list of 29 risk factors was generated; 20 originated from the scientific literature and nine from the expert panel. Risk factors were grouped in three clusters according to whether they pertained to the inherent risk (nine factors identified), risk mitigation (nine factors identified) or compliance of a hatchery with its preventive control plan and regulatory requirements (11 factors identified). Criteria for assessing each risk factor were defined based on common practices used in the Canadian hatchery industry. This comprehensive list of risk factors and criteria represents useful information to support the design and implementation of a Canadian risk assessment model for hatcheries, but could also be used by like‐minded food safety authorities.     

Reducing airborne pathogens and dust in commercial hatching cabinets with an electrostatic space charge system

Commercial hatcheries typically infuse hydrogen peroxide or formaldehyde gas into hatching cabinets to reduce airborne pathogens that may lead to disease transmission during the hatch. A nonchemical option, an electrostatic space charge system (ESCS), was customized for full-sized commercial hatching cabinets and was tested extensively in broiler hatcheries. The ESCS cleans air by transferring a strong negative electrostatic charge to dust and microorganisms that are aerosolized during the hatch and collecting the charged particles on grounded plates or surfaces. In studies with three poultry companies, the ESCS resulted in significant (P < 0.0001) reductions of airborne dust of 77%-79%, in Enterobacteriaceae and fungus levels not significantly different (P > or = 0.05) from those with formaldehyde, and in 93%-96% lower Enterobacteriaceae than with no treatment or with hydrogen peroxide treatment (P < 0.01). The ESCS significantly (P < 0.05) reduced airborne Salmonella by 33%-83% compared with no treatment or hydrogen peroxide treatment. Results of this study suggest that the ESCS is a viable alternative to chemical treatment for reducing airborne pathogens in full-sized commercial hatchers, and it also provides dust control and containment, which should be helpful in reducing cross contamination and loading of ventilation ducts within different areas of the hatchery.