Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Lange CE, Tobler K, Ackermann M, Favrot C.The number of recognized papillomavirus (PV) species and potential PV genera has dramatically been increasing throughout the past decade. It seems that every host species might potentially harbour a large set of PVs, while the PVs of each species appear to belong to only a few genera. In horses at least three conditions beside the equine sarcoid have been described, being supposedly PV induced namely classical equine papillomas, genital papillomas and aural plaques. We were able to identify the DNA of novel equine PVs (EcPVs) in the two latter disorders where PV involvement had been predicted....
Biggi M, Dyson S.There are no data concerning the accuracy of conventional and computed or digital radiography for evaluation of the equine foot. Objective: To compare conventional film-screen and computed radiography with magnetic resonance imaging (MRI) for detection of distal border fragments of the navicular bone; and to establish which type of fragment was more likely to be detected radiologically. Methods: Horses were included if forelimb lameness was localised to the foot and both radiography and high-field MR images had been acquired. Horses were divided into 2 groups based on acquisition of convention...
Scase T, Brandt S, Kainzbauer C, Sykora S, Bijmholt S, Hughes K, Sharpe S, Foote A.The aetiology of genital squamous cell carcinoma (SCC) in horses remains unknown, but the similarity to the disease in man, for which papillomavirus infection has been shown to be a causal factor, requires to be investigated in horses. Objective: One or more novel papillomaviruses cause equine genital SCC and its associated premalignant lesions. Methods: DNA was extracted from samples of equine genital SCC and performed rolling circle amplification, in order to identify closed circular DNA viral genomes within the samples. The amplified DNA was subcloned and sequenced and the DNA sequence comp...
Widmer A, Fürst A, Bettschart R, Makara M, Geyer H, Kummer M.This clinical report describes two horses with bilateral maxillary fractures following dental treatment. The fractures occurred during dental treatment by a veterinarian, and both had rostral, transverse, and complete bilateral maxillary fractures with instability and minimal displacement. The fractures were repaired using bilateral intraoral wiring with the patients under general anesthesia. The postoperative period was without complications and the fractures healed as expected. Maxillary fractures during or after routine dental treatment are rare, but can occur, especially in older horses. A...
Van Den Top JG, Ensink JM, Gröne A, Klein WR, Barneveld A, Van Weeren PR.Penile and preputial tumours are not uncommon in the horse, but can cause discomfort and lead to serious complications. Several types of tumour of the male external genitalia have been described. The most common type is the squamous cell carcinoma (SCC), which is found mainly in older horses. Reports of a breed predilection for penile tumour formation are equivocal, but castration, coat colour, poor hygiene and various infectious agents have all been suggested to predispose to the development of some types of tumour (e.g. SCC, papilloma and melanoma). Careful assessment of the primary tumour i...
Pigott JH, Ducharme NG, Mitchell LM, Soderholm LV, Cheetham J.The relationship between dorsal displacement of the soft palate (DDSP) and swallowing is unclear. Objective: To quantify the relationship between DDSP and swallowing in horses at exercise. Objective: The frequency of swallowing increases immediately prior to DDSP in horses at exercise. Methods: Videoendoscopic and upper airway pressure data were collated from horses with a definitive diagnosis of DDSP at exercise. Horses with no upper airway abnormalities were matched by age, breed and sex and used as controls. Sixty-nine horses were identified with a definitive diagnosis of DDSP during the st...
Freeman DE, Schaeffer DJ.To evaluate survival rate and complications after jejunocecostomy in horses with colic and to compare outcomes after hand-sewn versus stapled side-to-side jejunocecostomy. Methods: Retrospective cohort study. Methods: 32 horses. Methods: Information was retrieved from medical records and through telephone calls on horses that had a hand-sewn or stapled side-to-side jejunocecostomy for treatment of colic, which was performed by or under the supervision of the same surgeon. Kaplan-Meier life table analysis was used to compare survival times and rates between horses that underwent a hand-sewn or ...
Claridge HA, Piercy RJ, Parry A, Weller R.REASONS FOR STUDY: Detailed anatomy of the equine cervical articular process joints (APJs) has received little attention in the literature and yet disorders of this joint have been linked to spinal cord compression resulting in severe clinical signs such as ataxia and weakness. This study aimed to describe the 3D anatomy of the APJ in relation to the spinal cord in the horse. Objective: Artificial distension of the APJ causes the joint pouches to extend into the vertebral canal, with the potential for APJ effusion to cause spinal cord compressive disease. Methods: Six cadaveric necks (C1-C7) o...
Hermeyer K, Seehusen F, Gehlen H, Peters M, Wohlsein P.Cutaneous malignant lymphomas are rare in horses and comprise predominantly T-cell-rich B-cell lymphomas. They are characterized by multiple tumour nodules affecting predominantly female horses with a survival rate of months to years. At the final stage, metastases to regional lymph nodes occur, whereas widespread organ involvement is rarely reported. In this case report, a cutaneous T-cell-rich B-cell lymphoma in a 7-year-old standardbred gelding with metastases is described. Clinically, multiple cutaneous and subcutaneous nodules, enlarged superficial lymph nodes, rapid weight loss, and vent...
Asplin KE, Patterson-Kane JC, Sillence MN, Pollitt CC, Mc Gowan CM.Ponies with laminitis associated with insulin resistance and hyperinsulinaemia lack systemic and/or intestinal inflammatory signs, suggesting a different pathogenesis potentially reflected in differing histopathology. Objective: To describe the histological appearance and quantify morphological changes in primary and secondary epidermal lamellae (PEL and SEL) of laminitis lesions from ponies with insulin-induced laminitis. Methods: Equine hoof lamellar tissue was obtained from 4 control ponies and 5 ponies with laminitis induced following infusion of insulin (1036 ± 55 µU/ml) while maintai...
Morrissey NK, Bellenger CR, Ryan MT, Baird AW.To measure the expression of cyclooxygenase-2 (COX-2) mRNA in gastric biopsy specimens serially obtained from horses before, during, and after an 8-day intermittent feed-deprivation trial and to investigate the mucosal location of COX-2. Methods: 9 mixed-breed horses for retrieval of gastric biopsy specimens and 16 additional horses for immunohistochemical analysis. Methods: Gastric biopsy specimens were obtained from 6 horses; 3 of these horses and 3 more participated in an intermittent feed-deprivation trial 9 weeks later. A quantitative PCR assay was used to determine the amount of COX-2 mR...
Urosevic M, Lako B, Milanov D, Urosevic I, Aurich C.Uterine microbiology, antimicrobial susceptibility and endometrial cytology were investigated in a total of 51 mares with fertility problems from 16 different stud farms in Serbia. Uterine cultures were performed after collection with a double guarded uterine swab, and endometrial cytology was evaluated after collection of endometrial cells with a special device (cytology brush). In 21 of 51 mares, at least one bacterial species was isolated from the uterus; the most frequent were Streptococcus equi subsp. zooepidemicus (13 isolates) and E. coli (four isolates). All isolates of Streptococcus e...
Fiske-Jackson AR, Crawford AL, Archer RM, Bolt DM, Smith RK.To describe the diagnosis and treatment of fractures of the deltoid tuberosity. Methods: Case series. Methods: Medical records (1992-2009) of 19 horses with radiographic confirmation of deltoid tuberosity fractures were reviewed. Data retrieved included signalment, clinical and diagnostic imaging findings, and treatment. Outcome was determined by telephone questionnaire of owners and referring veterinarians. Results: Most horses were markedly lame on admission and 53% had reduced protraction of the affected limb. All fractures were identified on a cranio45° medial-caudolateral oblique project...
Kuiper H, Blum N, Distl O.In a 1.5-year-old Oldenburg horse, a clitoris-like structure instead of a penis was identified in the prepuce. The external genital organs did not show any abnormalities at visual inspection except that exteriorization of the penis was not possible, not even under general anesthesia. The horse's owner observed a continuous dripping of urine and a tendency to mild colics beginning 2 weeks after birth. Testosterone concentration was 0.01 ng/ml and therefore under the threshold for geldings, and the horse did not respond to the application of gonadotropin-releasing hormone (GnRH). The inner genit...
Mykkänen AK, Koho NM, Reeben M, McGowan CM, Pösö AR.Polymorphisms in human lactate transporter proteins (monocarboxylate transporters; MCTs), especially the MCT1 isoform, can affect lactate transport activity and cause signs of exercise-induced myopathy. Muscles express MCT1, MCT4 and CD147, an ancillary protein, indispensable for the activity of MCT1 and MCT4. We sequenced the coding sequence (cDNA) of horse MCT4 for the first time and examined polymorphisms in the cDNA of MCT1, MCT4 and CD147 of 16 healthy horses. To study whether signs of myopathy are linked to the polymorphisms, biopsy samples were taken from 26 horses with exercise-induced...
Pusterla N, Conrad PA, Packham AE, Mapes SM, Finno CJ, Gardner IA, Barr BC, Ferraro GL, Wilson WD.Over a 2-yr study period, we investigated possible endogenous transplacental transmission of Neospora hughesi in 74 mare and foal pairs following the diagnosis of neuronal neosporosis in a weanling foal. Presuckle and postsuckle serum of each foal, serum and colostrum of each periparturient mare, and serum of each mare and foal pair, collected at 3-mo intervals thereafter, were tested for N. hughesi using an indirect fluorescent antibody test (IFAT). Furthermore, whole blood and colostrum samples and placentae were tested for the presence of N. hughesi by real-time PCR. The mares' seroprevalen...
Cehak A, Rohn K, Barton AK, Stadler P, Ohnesorge B.Dynamic nasopharyngeal collapse with upper airway obstruction is an important cause of exercise intolerance in performance horses. Its underlying pathophysiology is not fully understood. We hypothesize that head position affects pharyngeal diameter, and thus head position may be a contributing factor to nasopharyngeal obstruction. Fifteen adult healthy horses were subjected to endoscopy and radiography at rest. The pharyngeal diameter was measured at nine different head and neck positions. The effect of sedation and breathing cycle on the pharyngeal diameter was determined, and the relationshi...
Pavone S, Veronesi F, Genchi C, Fioretti DP, Brianti E, Mandara MT.In this study, pathological changes caused by Anoplocephala perfoliata in the ileocecal junction were investigated in 31 regularly slaughtered mixed-breed horses of both sexes. Our results showed a significant relationship between parasite burden and grading of histopathological lesions in the mucosa and submucosa. Hypertrophy of the circular muscle layer was found in infected horses. Moreover, enteric nervous system evaluation showed a significant injury of intestinal nervous elements in the horses with moderate to high parasitism expressed as an increase of degenerative-regressive changes in...
Holowinski M, Judy C, Saveraid T, Maranda L.Magnetic resonance (MR) imaging is important in diagnosing musculoskeletal injuries in horses. However, there is still much to learn regarding the significance of lesions identified in equine MR images. Of particular importance is the clinical significance of signal change as a function of pulse sequence. We hypothesized that a resolution of tendon, ligament, and bone marrow lesions on short-tau inversion recovery (STIR) images would be associated with a return to soundness, and that a persistence of tendon and ligament lesions on only T1-weighted (T1w) gradient recalled echo (GRE) images woul...
Garrett KS, Woodie JB, Cook JL, Williams NM.A foal was examined for abnormal upper airway noise. Endoscopically, there were narrowed nasal passages and an extralumenal mass of the cranial trachea. Using ultrasonography and magnetic resonance (MR) imaging of the larynx and cranial cervical trachea, irregular margins of the laryngeal cartilages and first tracheal ring containing areas consistent with fluid were identified. In MR images, a widened nasal septum was seen that contained material consistent with fluid. Postmortem examination confirmed the diagnosis of nasal septal, laryngeal, and cranial cervical tracheal cyst-like lesions. Th...
Figueredo LA, Cafarchia C, Otranto D.Fungi of the genus Geotrichum are commonly found in the environment and, in some circumstances, they may cause diseases in humans and animals. Although these fungi have been isolated from skin lesions of some animal species, their pathogenic role in horses remains uncertain. With the aim to investigate the role of Geotrichum candidum as etiological agent of dermatomycoses, a retrospective study of 64 horses presenting skin lesions and suspected to have fungal infections was carried out. For each animal, anamnestic data were recorded and fungal culture were performed using hair. Out of 64 cases...
Hobo S, Niwa H, Anzai T, Jones JH.In this study, to evaluate the influence of strangles vaccination on serological test results, we investigated the changes in strangles serum antibody levels in horses after vaccination and subsequent intranasal challenge with S. equi. The horses were vaccinated for strangles with either a component vaccine (Group C) or a live vaccine (Group L). We measured changes in strangles serum antibody levels weekly for 20 weeks after vaccinating horses twice for strangles over a 3-week interval, and for 7 weeks after intranasal challenge with S. equi in the same horses. Serum antibody responses to the ...
Podadera JM, Bell RJ, Dart AJ.Two horses presented with a history of severe lameness that was localised to the area around the second phalanx (P2) of one forelimb. Radiographs of the second phalanx of both horses were unremarkable, apart from some smooth periosteal new bone production on the dorsum of P2. Magnetic resonance imaging revealed a non-displaced fracture of P2 in both horses. One horse was euthanased because of a poor prognosis for racing, but the second horse was treated conservatively and salvaged for breeding. Magnetic resonance imaging is a newer imaging modality in horses and may be useful in diagnosing cas...
Quinteros DD, García-López JM, Provost PJ.To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. Methods: The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. Results: The mean age was 10 years (range 2-22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had ty...
Collins NM, Palmer L, Marr CM.The aim of this study was to establish reference values for a series of conventional two-dimensional (2-D) and M-mode echocardiographic variables in Thoroughbred foals at increasing age intervals. Methods: Nineteen healthy Thoroughbred foals (11 males, 8 females) were examined at 1, 2, 4, 8, 12 and 16 weeks of life. Auscultatory findings were recorded and echocardiographic examinations (2-D and M-mode) were performed. Descriptive statistical analyses, including mean, standard deviation and 95% confidence interval for the means, were used to summarise the data. The relationships between selecte...
Corteggio A, Di Geronimo O, Roperto S, Roperto F, Borzacchiello G.Studies regarding the functions of the bovine papillomavirus (BPV) E7 oncoprotein in vivo are lacking and no E7-mediated mechanism underlying mesenchymal carcinogenesis is known. Here, we show that the interaction between the 600 kDa retinoblastoma protein-associated factor (p600) and BPV E7, described in vitro in cultured cells, takes place in vivo in naturally occurring equine sarcoids. In these cancers we detect the expression of E7 and p600, and demonstrate that E7 and p600 co-localize and physically interact. Furthermore, intracellular signals involved in p600 functional activity are foun...
Perron Lepage MF, Gerber V, Suter MM.Subacute interstitial pneumonia with diffuse alveolar damage, marked macrophage infiltration, and intracellular Pneumocystis carinii cysts is described in a 3-month-old Swiss warmblood foal. Clinically, the disease was characterized by sudden onset of respiratory distress with fatal outcome. Based on serum immunoglobulin G (IgG), IgA, and IgM values, no humoral immunosuppression was detected. Spleen, thymus, and bronchial lymph nodes did not reveal lymphoid depletion, as assessed by immunohistochemical staining of CD-3-positive cells. Immunopathogenesis of pulmonary infections with intracellul...
Bueschel D, Walker R, Woods L, Kokai-Kun J, McClane B, Songer JG.A Thoroughbred-Quarter Horse crossbred foal developed hemorrhagic enteritis and died < 48 hours after birth. Gross and histologic findings were suggestive of Clostridium perfringens type C infection, and large numbers of C perfringens were isolated from intestinal contents. However, genotyping of isolates indicated that they were enterotoxigenic C perfringens type A, and isolates were found to produce C perfringens enterotoxin in vitro. This case suggests that enterotoxigenic C perfringens type A may cause enteric disease in horses.
Dixon PM, Savill D, Horbyl A, Reardon RJ, Liuti T.Infundibular caries of the equine maxillary cheek teeth is an important disorder that can lead to dental fracture or apical infection. Treatment by removing food debris and carious dental tissue from affected infundibulae using high-pressure abrasion with aluminium hydroxide micro-particles, followed by filling the cleaned defect with endodontic restorative materials is a recommended treatment. However, although anecdotally considered a successful treatment option, there is currently no objective evidence to support this claim. Forty maxillary cheek teeth (CT) that contained 55 infundibulae wi...
Caltabilota TJ, Earl LR, Thompson DL, Clavier SE, Mitcham PB.Four experiments were conducted 1) to assess the use of glucose responses to insulin injections as a means of estimating insulin sensitivity in horses and 2) to compare the insulin sensitivities of normal horses vs. those displaying hyperleptinemia (HL). In Exp. 1, HL mares and geldings (n = 4 each) and 4 mares and geldings with normal leptin concentrations (NL) were injected intravenously with 20 and 100 mU/kg of BW of bovine insulin on 2 separate occasions in December 2008. In Exp. 2, the experimental protocol was repeated in late April 2009. In Exp. 1, the 20 mU/kg of BW dose of insulin cau...
Johnson JS, Hibler CP, Tillotson KM, Mason GL.An adult horse was euthanatized following a clinical diagnosis of cauda equina neuritis. Significant gross postmortem and histopathologic findings were limited to the sacral spinal cord and cauda equina. The sacral spinal cord, meninges, and spinal nerve roots were expanded and partially effaced by sclerosing granulomatous inflammation with necrosis. The lesion contained numerous nematode larvae and fewer adults with a rhabditiform esophagus having a corpus, isthmus, and valved bulb. Female nematodes were amphidelphic and didelphic with reflexed ovaries. These morphologic features confirm Hali...
Junge RE, Sundberg JP, Lancaster WD.In a retrospective study encompassing 13 years of diagnostic work, papillomas and squamous cell carcinomas from horses were screened for papilloma-virus antigens, using the peroxidase-antiperoxidase technique. Papillomas were most commonly found on the penis and vulva, followed by cutaneous, ocular, and oral locations. Squamous cell carcinomas were most frequently located on the third eyelid and cornea, followed by genital, oral, maxillary sinus, and cutaneous sites. Papillomavirus structural antigens were detected in 7 cutaneous and 5 genital papillomas, but not in squamous cell carcinomas.
Crispe EJ, Lester GD, Robertson ID, Secombe CJ.Ambient temperature has been identified as a risk factor for exercise-induced pulmonary haemorrhage (EIPH) in racing Thoroughbreds. This warranted a more expansive investigation of climatic conditions on the incidence and severity of EIPH. The impact of other variables such as the type of bit used, tongue ties and nonstandard shoes has not been reported and also warrant investigation. Objective: To examine the effect of various climatic variables as contributing risk factors for EIPH. Other previously uninvestigated variables as well as standard track and population factors will also be examin...
Hanche-Olsen S, Teige J, Skaar I, Ihler CF.Cases of hindlimb digital extensor weakness of unknown etiology have been observed in Norway since 1995. Objective: We hypothesized that the observed bilateral extensor weakness was attributable to neuropathy of the distal nerves and that this was related to environmental factors, possibly dietary. Methods: Seventy-five horses with digital extensor weakness occurring from 1995 to 2004 are described. Methods: Eleven horses were examined at The Norwegian School of Veterinary Science, and the medical records of 64 horses seen in ambulatory practice were reviewed. Results: There was no apparent se...
Butler J, Khan S, Scarzella G.Two young American miniature horses from the same farm were evaluated by a veterinarian due to presence of lethargy, anorexia, and cardiac arrhythmias. Both horses were treated aggressively with IV fluids and other supportive measures. The first horse died approximately 72 hr after the start of clinical signs and the second horse was humanely euthanized due to poor response to treatment. Oleander toxicosis was suspected based on the types of clinical signs present and due to several oleander plants and dried leaves present on the property. Oleander toxicosis was confirmed by the presence of ol...
Sykes CA, Uzal FA, Mete A, Ochoa J, Filigenzi M, Poppenga RH, Asin J.A presumptive postmortem diagnosis of oleander () poisoning is made based on the histological observation of cardiomyocyte degeneration and necrosis, which is considered to be a reliable diagnostic marker, and can be confirmed via the detection of oleandrin in tissues or fluids. However, cardiac lesions may not be present in every case, and autolysis can often preclude the identification of subtle changes in the cardiomyocytes. Several studies of experimental oleander poisoning have noted the presence of renal lesions in multiple mammalian species, and case studies of accidental exposure have ...
Magnarelli LA, Ijdo JW, Van Andel AE, Wu C, Fikrig E.To develop and evaluate a polyvalent ELISA incorporating a highly specific recombinant antigen (p44) for diagnosis of granulocytic ehrlichiosis in dogs and horses. Methods: 32 dogs and 43 horses. Methods: Results of the ELISA were compared with results of indirect fluorescent antibody (IFA) staining and western immunoblotting incorporating whole-cell antigen. Results: For the canine and equine samples, percentages of samples with positive IFA staining, western immunoblotting, and ELISA results were similar. For 29 (91 %) canine samples and 30 (70%) equine samples, results of IFA staining, west...
Swink JM, Gilsenan WF.Botulism and tetanus are the 2 primary manifestations of neurologic disease caused by clostridial toxins. Only a small dose of clostridial toxin is required to induce severe, and often fatal, disease. Consequently, definitive diagnosis of either disease is nearly impossible to achieve antemortem or postmortem; presumptive diagnosis is usually made based on physical and neurologic examination findings. Because the severity of clinical signs can worsen rapidly, prognosis worsens when therapeutic intervention is delayed. Highly effective vaccines are available against both botulism and tetanus an...
Gilger BC, Davidson MG, Nadelstein B, Nasisse M.To determine clinical features of cystic granula iridica in horses and outcome of horses treated with an ophthalmic neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Methods: Retrospective study. Methods: 8 horses. Methods: An ophthalmic Nd:YAG laser was used to deflate cysts in all horses. Results: Horses were examined because of visual impairment (n = 5), decreased jumping performance (2), or head shaking (1). Clinical signs associated with cysts resolved in all horses after treatment. Short- and long-term complications did not develop, and cysts did not recur. Conclusions: Cystic granula ir...
Koenig JB, Westlund A, Nykamp S, Kenney DG, Melville L, Cribb N, Oberbichler D.The accuracy of using radiographs to diagnose cervical facet osteoarthritis (CFA) in horses is undetermined. Further investigation is required to determine the clinical significance of radiographic evidence of CFA, the prevalence of radiographic changes in horses without clinical signs, and the long-term efficacy of intra-articular CFA treatment. The objectives of this study is to compare degenerative changes of the cervical facet joints of the cervical vertebrae on radiographs of horses with clinical signs of CFA with healthy cohort-matched horses, to compare clinical findings between groups,...
Bertone JJ, Traub-Dargatz JL, Wrigley RW, Bennett DG, Williams RJ.Four horses with diarrhea had radiographic evidence of large quantities of sand in the gastrointestinal tract. Initially, none of the horses had sufficient fecal sand quantity to suggest sand enteropathy. Diarrhea resolved in all horses within 2 days of oral administration of psyllium hydrophilic mucilloid. Historically, all 4 horses had lost weight or had difficulty maintaining weight. After treatment was administered, the horses either gained weight or were easier to maintain in good condition.
Mendoza FJ, Perez-Ecija RA, Monreal L, Estepa JC.Coagulation disorders are frequently diagnosed, especially in hospitalized equidae, and result in increased morbidity and mortality. However, hemostatic reference intervals have not been established for donkeys yet. Objective: To determine whether the most common coagulation parameters used in equine practice are different between healthy donkeys and horses. Methods: Thirty-eight healthy donkeys and 29 healthy horses. Methods: Blood samples were collected to assess both coagulation and fibrinolytic systems by determination of platelet count, fibrinogen concentration, clotting times (prothrombi...
Morley PS.Surveillance for nosocomial infection and disease is a critical component in an integrated and highly effective infection control program. Surveillance activities provide a sensory role to guide ongoing control practices so that they are focused and efficient. Without input from surveillance results, infection control practices are likely to be guided more by emotion and opinion than by data and evidence. This article discusses issues to be considered when developing effective nosocomial infection surveillance programs as well as the historical perspective of surveillance efforts for nosocomia...