Caracterización de la atención a la salud ocupacional en el Policlínico Juan José Apolinaire Pennini. Cienfuegos, 2018 / Characterization of the attention to the Occupational Health in the Policlínico Juan José Apolinaire Pennini. Cienfuegos 2018

RESUMEN Fundamento: considerando que los accidentes de trabajo constituyen cuantiosa fuente de generación de costos y que en Cuba existe una distribución etaria envejecida, la atención a la salud de los trabajadores es un proceso fundamental en la atención primaria de salud. Objetivo: caracterizar la atención a la salud ocupacional en el Policlínico Juan José Apolinaire Pennine de Cienfuegos. Métodos: e studio descriptivo, de corte transversal realizado en 2018. La muestra constituida por trabajadores de la Termoeléctrica Carlos Manuel de Céspedes, escogida por muestreo simple aleatorio y médicos y enfermeras de la familia del policlínico, seleccionados de forma intencional. Para obtener la información se utilizaron dos instrumentos, uno aplicado al personal de la salud, para identificar conocimiento sobre salud ocupacional y otro a los trabajadores de la empresa seleccionada para determinar satisfacción percibida con la atención recibida. Resultados: en los profesionales del policlínico Juan José Apolinaire Pennini de Cienfuegos, se evidencia falta de conocimiento sobre salud ocupacional, al no mostrar claridad sobre riesgos laborales, causas de accidentes de trabajo, exámenes a realizar en población trabajadora y criterios para declarar una enfermedad profesional. Además los pacientes encuestados se encuentran medianamente satisfechos con la atención recibida, fundamentalmente por deficiencias en estabilidad, necesidad e integralidad de la atención. Conclusión: los resultados de la investigación son sugerentes de que existe una relación entre la falta de conocimiento sobre salud ocupacional en trabajadores del policlínico y la insuficiente atención percibida por los pacientes encuestados.

ABSTRACT Background: considering that work accidents constitute a large source of cost generation and that in Cuba there is an aging age distribution, health care for workers is a fundamental process in primary health care. Objective: to characterize occupational health care at the Juan José Apolinaire Pennine Polyclinic in Cienfuegos. Methods: descriptive, cross-sectional study carried out in 2018. The sample made up of workers from the Carlos Manuel de Céspedes Thermoelectric Plant, chosen by simple random sampling, and doctors and nurses from the polyclinic family, intentionally selected. To obtain the information, two instruments were used, one applied to health personnel, to identify knowledge about occupational health and the other to the workers of the selected company to determine perceived satisfaction with the care received. Results: in the professionals of the Juan José Apolinaire Pennini polyclinic in Cienfuegos, there is evidence of a lack of knowledge about occupational health, by not showing clarity about occupational risks, causes of work accidents, examinations to be carried out in the working population and criteria for declaring an occupational disease . In addition, the surveyed patients are moderately satisfied with the care received, mainly due to deficiencies in stability, need and comprehensiveness of care. Conclusion: the research results suggest that there is a relationship between the lack of knowledge about occupational health in polyclinic workers and the insufficient attention perceived by the surveyed patients.

Gastric lymphoma at high risk of perforation successfully managed with chemotherapy alone.

We report the case of a previously healthy 49-year-old woman who presented with upper gastrointestinal bleeding, which was found at laparotomy to be due to high-grade B cell gastric lymphoma. CT scans showed that this was partially adherent to the spleen, with erosion of the gastric wall and suggested impending perforation. Given the risk of perforation, further surgical intervention (gastrectomy and splenectomy) was considered; however, after multidisciplinary team discussion, we chose to offer chemotherapy and careful inpatient observation instead.Our patient made a full recovery with no perforation.The message from our experience and literature review is that medical management may lead to a more favourable outcome in gastric lymphoma than surgery, despite radiological appearances suggesting impending perforation. This approach avoids the risk of the lymphoma progressing at other anatomical sites secondary to delays in giving chemotherapy. If this approach is followed, the patient must be carefully monitored.

Non-Linear Regression Modelling to Estimate the Global Warming Potential of a Newspaper.

Technological innovations are not enough by themselves to achieve social and environmental sustainability in companies. Sustainable development aims to determine the environmental impact of a product and the hidden price of products and services through the concept of radical transparency. This means that companies should show and disclose the impact on the environment of any good or service. This way, the consumer can choose in a transparent manner, not only for the price. The use of the eco-label as a European eco-label, which bases its criteria on life cycle assessment, could provide an indicator of corporate social responsibility for a given product. However, it does not give a full guarantee that the product was obtained in a sustainable manner. The aim of this work is to provide a way of calculating the value of the environmental impacts of an industrial product, under different operating conditions, so that each company can provide detailed information on the impacts of its products, information that can form part of its "green product sheet". As a case study, the daily production of a newspaper, printed by coldset, has been chosen. Each process involved in production was configured with raw material and energy consumption information from production plants, manufacturer data and existing databases. Four non-linear regression models have been trained to estimate the impact of a newspaper's circulation from five input variables (pages, grammage, height, paper type, and print run) with 5508 data samples each. These non-linear regression models were trained using the Levenberg-Marquardt nonlinear least squares algorithm. The mean absolute percentage errors (MAPE) obtained by all the non-linear regression models tested were less than 5%. Through the proposed correlations, it is possible to obtain a score that reports on the impact of the product for different operating conditions and several types of raw materials. Ecolabelling can be further developed by incorporating a scoring system for the impact caused by the product or process, using a standardised impact methodology.

In vitro evaluation of commercial foam Belcils® on Acanthamoeba spp.

Interest in periocular (eyelid and eyelashes margins) hygiene has attracted attention recently and a growing number of commercials eye cleanser and shampoos have been marketed. In the present study, a particular eye cleanser foam, Belcils® has been tested against trophozoites and cysts on the facultative pathogen Acanthamoeba. Viability was tested by the alamarBlue™ method and the foam was tested for the induction of programmed cell death in order to explore its mode of action. We found that a 1% solution of the foam eliminated both trophozoite and cyst stage of Acanthamoeba spp. After 90 min of incubation, Belcils® induced, DNA condensation, collapse in the mitochondrial membrane potential and reduction of the ATP level production in Acanthamoeba. We conclude that the foam destroys the cells by the induction of an apoptosis-like process. The current eye cleanser could be used as part of AK therapy protocol and as prevention from AK infections for contact lens users and post-ocular trauma patients.

Autoimmune pancytopenia occurring late after simultaneous pancreas and kidney transplantation.

A 35-year-old woman presented with a widespread petechial rash and pancytopenia. She underwent simultaneous pancreas and kidney transplantation for type 1 diabetes 8 years previously followed by a renal transplant 1 year prior to presentation, and was taking tacrolimus as long-term immunosuppression. The full blood count showed haemoglobin 97 g/L, platelet count 2×109/L and neutrophil count 0.22×109/L. Peripheral blood film examination confirmed genuine thrombocytopenia in the absence of any haemolytic or malignant features. Serological testing identified autoantibodies against all three blood lineages, consistent with a diagnosis of autoimmune pancytopenia. Treatment with steroids, intravenous immunoglobulins, romiplostim and mycophenolate mofetil achieved only fleeting remissions. Blood counts eventually normalised following the administration of rituximab and a change from tacrolimus to ciclosporin immunosuppression. Cytopenias are a well-recognised complication of post-transplantation care but we believe this to be the first reported case of autoimmune pancytopenia following solid organ transplantation. In this case report, we discuss the approach to investigation of haematological abnormalities post-transplant and the rationale for, and outcome of, the management of this rare case.

In Vitro Activity of Statins against Naegleria fowleri.

Naegleria fowleri causes a deadly disease called primary amoebic meningoencephalitis (PAM). Even though PAM is still considered a rare disease, the number of reported cases worldwide has been increasing each year. Among the factors to be considered for this, awareness about this disease, and also global warming, as these amoebae thrive in warm water bodies, seem to be the key factors. Until present, no fully effective drugs have been developed to treat PAM, and the current options are amphotericin B and miltefosine, which present side effects such as liver and kidney toxicity. Statins are able to inhibit the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which is a key enzyme for the synthesis of ergosterol of the cell membrane of these amoebae. Therefore, the in vitro activity of a group of statins was tested in this study against two types of strains of Naegleria fowleri. The obtained results showed that fluvastatin was the most effective statin tested in this study and was able to eliminate these amoebae at concentrations of 0.179 ± 0.078 to 1.682 ± 0.775 µM depending on the tested strain of N. fowleri. Therefore, fluvastatin could be a potential novel therapeutic agent against this emerging pathogen.

In Vitro Evaluation of Combined Commercialized Ophthalmic Solutions Against Acanthamoeba Strains.

Acanthamoeba is a free-living amoebae genus which is present worldwide in natural and artificial environments. These amoebae are clinically important as causative agents of diseases in humans and other animals such as a fatal encephalitis or a sight threatening Acanthamoeba keratitis (AK). Lately; studies have focused on the search of novel therapeutic options for AK but also to prevent infections. Furthermore; the evaluation of commercialized products seems to be an option for this case since not clinical assays would be required. Thus; we aimed to test the amoebicidal activity of different mixtures of two commercial ophthalmic solutions: Systane® Ultra; which has already shown anti-Acanthamoeba properties; and Naviblef® Daily Care. In addition, we tested their cytotoxic effect against murine macrophages. At the individual level; Naviblef® Daily Care showed to be the most active product against Acanthamoeba spp. Nevertheless; the combinations of Systane® Ultra and Naviblef® Daily Care; showed an improvement in the activity against trophozoites and cysts of Acanthamoeba castellanii Neff. Moreover; the concentration necessary to generate cytotoxic effect against murine macrophages (J774.1) was much higher than the required for the amoebicidal and cysticidal effect achieved in the most effective mixtures.

Perfil clínico, epidemiológico y geográfico de casos de dengue durante el fenómeno El Niño Costero 2017, Lambayeque-Perú / Clinical, epidemiological and geographic profile of dengue cases during El Niño Costero Phenomenon 2017, Lambayeque-Perú

Introducción: En la actualidad, el dengue persiste como un problema latente para la salud pública en nuestro país; se debe tener en cuenta también que los casos de dengue han presentado una tendencia creciente en los últimos 5 años, en 2017 una cifra de 76 093 casos (3.03 veces más casos en relación con 2016), y 93 muertes, la mayor cifra en los últimos 5 años. Objetivo: Describir el perfil clínico, epidemiológico y geográfico del dengue en la Red EsSalud Lambayeque 2017, durante El Niño Costero. Material y métodos: Pacientes captados por sistema de vigilancia epidemiológica que cuentan con ficha epidemiológica con diagnóstico clínico de dengue de todas las edades, ambos sexos, atendidos en la red asistencial EsSalud-Lambayeque durante el fenómeno El Niño Costero. Se utilizó estadística descriptiva con cálculo de frecuencias absolutas y relativas para las variables cualitativas y media con desviación estándar para las cuantitativas y software libre QGis 2.14 para georreferenciación. Resultados: La edad fue 7.2 + 20.4 años, 27,9 por ciento procedentes de Chiclayo, 52,9 por ciento fueron mujeres, 77 por ciento presentaron dengue sin signos de alarma, 1,5 por ciento fallecidos. De los 874 casos, 335 (38,3 por ciento ) casos fueron positivos 213 (63,5 por ciento ) por laboratorio. La clínica más frecuente fue fiebre, cefalea, artralgia y mialgia. El signo de alarma más frecuente fue disminución de plaquetas. Conclusiones: El dengue afectó en mayor frecuencia a la población adulta, femenina, procedente de Chiclayo; clínicamente sin signos de alarma(AU)

Introduction: At present, dengue fever persists as a latent problem for public health in our country. It should also be borne in mind that the cases of dengue fever have presented a growing trend during the last 5 years, with a number of 76 093 cases in 2017 (3.03 times more cases with respect to the year 2016); and 93 deaths, which represents the highest figure in the last 5 years. Objective: To describe the clinical, epidemiological and geographical profile of dengue fever in the EsSalud Lambayeque Network 2017, during El Niño Costero Phenomenon. Material and Methods: Patients of all ages and both sexes with an epidemiological record of a clinical diagnosis of dengue identified by the epidemiological surveillance system, in the EsSalud-Lambayeque Health Care Network, during El Niño Costero Phenomenon. Descriptive statistics with calculation of absolute and relative frequencies for qualitative variables and mean with standard deviation for quantitative and free software QGis 2.14 for georeferencing. Results: The age was 7.2 + 20.4 years, 27.9 percent from Chiclayo, 52.9 percent were women; 77 percent had dengue without warning signs, 1.5 percent died. Of the 874 cases, 335 ones (38.3 percent) were positive, and 213 (63.5 percent) were diagnosed from reference laboratory. The most frequent clinical symptoms and signs were fever, headache, arthralgia and myalgia. The most frequent alarm sign was decrease in platelet. Conclusions: Dengue fever affected the adult female population from Chiclayo more frequently; presenting no clinical warning signs(AU)

Toxic effects of selected proprietary dry eye drops on Acanthamoeba.

Amoebae of the genus Acanthamoeba are ubiquitous protists that have been isolated from many sources such as soils, water and the air. They are responsible for infections including fatal encephalitis and a severe keratitis in humans. To date, there is no satisfactorily effective therapeutic agent against this pathogen and the infections it causes are exacerbated by the existence of a resistant cyst stage produced by this amoeba. As dry eye syndrome is a risk factor for Acanthamoeba keratitis, we aimed to evaluate the anti-Acanthamoeba activity of a variety of proprietary eye drops intended to treat dry eye syndrome. From the nine eye drop formulations tested, "Systane Ultra" was determined to be the most active against all tested Acanthamoeba strains. During our investigations into the mode of action of Systane Ultra, we discovered that it decreases mitochondrial membrane potential and ATP levels, induces chromatin condensation, and increases the permeability of the plasma-membrane.

Presence of Acanthamoeba in the ocular surface in a Spanish population of contact lens wearers.

Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis (AK) which mainly affects contact lens wearers and it is commonly related to poor hygiene of contact lenses and their cases. Moreover, treatment of AK is complex due to the existence of a highly resistant cyst stage and if not diagnosed early has poor prognosis, leading to blindness and/or keratoplasty. Even though AK is increasing worldwide as well as awareness among patients and clinicians, it is still a poorly studied pathogen. Additionally, a remaining question to be answered is whether these opportunistic pathogens are present in the ocular surface of healthy contact lens wearers since they are the main group at risk.In order to carry out this study, sterile Schirmer strip tests were collected from a group of individuals all of them contact lens wearers who were attending a local ophthalmology clinic in Tenerife, Canary Islands, Spain. The collected samples (100 eyes of 50 patients) were cultured in 2% Non-Nutrient Agar (NNA) plates and positive plates (16) were then cultured in axenic conditions for further analyses. Molecular analysis classified all isolated strains belonged to Acanthamoeba genotype T4 and osmotolerance and thermotolerance assays revealed that all strains were potentially pathogenic. In conclusion, the ocular surface of contact lens wearers included in this study was colonized by potentially pathogenic strains of Acanthamoeba and should be considered as a risk for AK infection in this region and worldwide.

The additional benefit of residual spraying and insecticide-treated curtains for dengue control over current best practice in Cuba: Evaluation of disease incidence in a cluster randomized trial in a low burden setting with intensive routine control.

BACKGROUND: Aedes control interventions are considered the cornerstone of dengue control programmes, but there is scarce evidence on their effect on disease. We set-up a cluster randomized controlled trial in Santiago de Cuba to evaluate the entomological and epidemiological effectiveness of periodical intra- and peri-domiciliary residual insecticide (deltamethrin) treatment (RIT) and long lasting insecticide treated curtains (ITC). METHODOLOGY/PRINCIPAL FINDINGS: Sixty three clusters (around 250 households each) were randomly allocated to two intervention (RIT and ITC) and one control arm. Routine Aedes control activities (entomological surveillance, source reduction, selective adulticiding, health education) were applied in the whole study area. The outcome measures were clinical dengue case incidence and immature Aedes infestation. Effectiveness of tools was evaluated using a generalized linear regression model with a negative binomial link function. Despite significant reduction in Aedes indices (Rate Ratio (RR) 0.54 (95%CI 0.32-0.89) in the first month after RIT, the effect faded out over time and dengue incidence was not reduced. Overall, in this setting there was no protective effect of RIT or ITC over routine in the 17months intervention period, with for house index RR of 1.16 (95%CI 0.96-1.40) and 1.25 (95%CI 1.03-1.50) and for dengue incidence RR of 1.43 (95%CI 1.08-1.90) and 0.96 (95%CI 0.72-1.28) respectively. The monthly dengue incidence rate (IR) at cluster level was best explained by epidemic periods (Incidence Rate Ratio (IRR) 5.50 (95%CI 4.14-7.31)), the IR in bordering houseblocks (IRR 1.03 (95%CI 1.02-1.04)) and the IR pre-intervention (IRR 1.02 (95%CI 1.00-1.04)). CONCLUSIONS: Adding RIT to an intensive routine Aedes control programme has a transient effect on the already moderate low entomological infestation levels, while ITC did not have any effect. For both interventions, we didn't evidence impact on disease incidence. Further studies are needed to evaluate impact in settings with high Aedes infestation and arbovirus case load.

Evaluation of the anti-Acanthamoeba activity of two commercial eye drops commonly used to lower eye pressure.

Efficient treatments against Acanthamoeba Keratitis (AK), remains until the moment, as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. In this study, two antiglaucoma eye drops were tested for their activity against Acanthamoeba. Moreover, this study was based on previous data which gave us evidence of a possible link between the absences of Acanthamoeba at the ocular surface in patients treated with beta blockers for high eye pressure both containing timolol as active principle. The amoebicidal activity of the tested eye drops was evaluated against four strains of Acanthamoeba using Alamar blue method. For the most active drug the cysticidal activity against A. castellanii Neff cysts and further experiments studying changes in chromatin condensation levels, in the permeability of the plasmatic membrane, the mitochondrial membrane potential and the ATP levels in the treated amoebic strains were done. Even though both eye drops were active against the different tested strains of Acanthamoeba, statistical analysis revealed that one of them (Timolol Sandoz) was the most effective one against all the tested strains presenting IC50s ranging from 0.529% ± 0.206 for the CLC 16 strain to 3.962% ± 0.150 for the type strain Acanthamoeba castellanii Neff. Timolol Sandoz 0.50% seems to induce amoebic cell death by damaging the amoebae at the mitochondrial level. Considering its effect, Timolol Sandoz 0.50% could be used in the case of contact lens wearers and patients with glaucoma.

Incremental cost of implementing residual insecticide treatment with delthametrine on top of intensive routine Aedes aegypti control.

OBJECTIVE: Information on the cost of implementing residual insecticide treatment (RIT) for Aedes control is scarce. We evaluated the incremental cost on top of intensive conventional routine activities of the Aedes control programme (ACP) in the city of Santiago de Cuba, Cuba. METHODS: We conducted the cost analysis study in 2011-2012, from the perspective of the ACP. Data sources were bookkeeping records, activity registers of the Provincial ACP Centre and the accounts of an RIT implementation study in 21 clusters of on average four house blocks comprising 5180 premises. RESULTS: The annual cost of the routine ACP activities was 19.66 US$ per household. RIT applications in rounds at 4-month intervals covering, on average, 97.2% and using 8.5 g of delthametrine annually per household, cost 3.06 US$ per household per year. Delthametrine comprised 66.5% of this cost; the additional cost for deploying RIT comprised 15.6% of the total ACP routine cost and 27% of the cost related to routine adult stage Aedes control. CONCLUSIONS: The incremental cost of implementing RIT is high. It should be weighed against the incremental effect on the burden caused by the array of pathogens transmitted by Aedes. The cost could be reduced if the insecticide became cheaper, by limiting the number of yearly applications or by targeting transmission hot spots.

Bitopic Sphingosine 1-Phosphate Receptor 3 (S1P3) Antagonist Rescue from Complete Heart Block: Pharmacological and Genetic Evidence for Direct S1P3 Regulation of Mouse Cardiac Conduction.

The molecular pharmacology of the G protein-coupled receptors for sphingosine 1-phosphate (S1P) provides important insight into established and new therapeutic targets. A new, potent bitopic S1P3 antagonist, SPM-354, with in vivo activity, has been used, together with S1P3-knockin and S1P3-knockout mice to define the spatial and functional properties of S1P3 in regulating cardiac conduction. We show that S1P3 is a key direct regulator of cardiac rhythm both in vivo and in isolated perfused hearts. 2-Amino-2-[2-(4-octylphenyl)ethyl]propane-1,3-diol in vivo and S1P in isolated hearts induced a spectrum of cardiac effects, ranging from sinus bradycardia to complete heart block, as measured by a surface electrocardiogram in anesthetized mice and in volume-conducted Langendorff preparations. The agonist effects on complete heart block are absent in S1P3-knockout mice and are reversed in wild-type mice with SPM-354, as characterized and described here. Homologous knockin of S1P3-mCherry is fully functional pharmacologically and is strongly expressed by immunohistochemistry confocal microscopy in Hyperpolarization Activated Cyclic Nucleotide Gated Potassium Channel 4 (HCN4)-positive atrioventricular node and His-Purkinje fibers, with relative less expression in the HCN4-positive sinoatrial node. In Langendorff studies, at constant pressure, SPM-354 restored sinus rhythm in S1P-induced complete heart block and fully reversed S1P-mediated bradycardia. S1P3 distribution and function in the mouse ventricular cardiac conduction system suggest a direct mechanism for heart block risk that should be further studied in humans. A richer understanding of receptor and ligand usage in the pacemaker cells of the cardiac system is likely to be useful in understanding ventricular conduction in health, disease, and pharmacology.

Estrategia didáctica para la formación científica de los estudiantes de tecnología de la salud / Didactic strategy for the scientific training of the health technology students

En este trabajo se presenta una estrategia didáctica conformada por cuatro etapas, dirigida a los estudiantes de tecnología de la salud que cursan las carreras de optometría, óptica y rehabilitación en salud, con vistas a dinamizar y desarrollar la autoformación científica de estos a través del proceso docente-educativo de la disciplina Informática e Investigación. La validación de la estrategia y su implementación se realizaron mediante los criterios de especialistas, con la aplicación de métodos teóricos y prácticos, y de procedimientos para la recolección de la información, que posteriormente fue tabulada. Los principales resultados se significaron a través del incremento en la participación de las actividades científicas como forma evaluativa final de algunas asignaturas, el mejoramiento en la calidad de los trabajos presentados, el aumento de la motivación por las actividades investigativas y el incremento de los estudiantes afiliados a las sociedades científicas de sus carreras(AU)

In this work, a didactic strategy formed by four stages, directed to the health technology students who study the optometry, optics and rehabilitation careers is presented, with the objective of making dynamic and developing their scientific self-training through the teaching-educational process of the Computing and Investigation disciplines. The validation of the strategy and its implementation were carried out by means of the specialists criteria, with the use of theoretical and practical methods, and of procedures for gathering the information that was tabulated later on. The main results were represented by the increase in the participation on scientific activities as final evaluative way of some subjects, the improvement in the quality of the presented works, the increase of motivation for investigative activities and the increase of affiliated students to the scientific societies of their careers(AU)

Detection of Acanthamoeba on the ocular surface in a Spanish population using the Schirmer strip test: pathogenic potential, molecular classification and evaluation of the sensitivity to chlorhexidine and voriconazole of the isolated Acanthamoeba strains.

Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis, which is often associated with the misuse of contact lenses. However, there is still a question remaining to be answered, which is whether these micro-organisms are present on the ocular surface of healthy individuals. Therefore, the aim of this study was to determine the presence of Acanthamoeba on the ocular surface in healthy patients and also in those with other ocular surface infections. Sterile Schirmer test strips were used to collect samples from a group of patients who attended an ophthalmology consultation at the Hospital del Norte, Icod de los Vinos, Tenerife, Canary Islands. Most of the patients (46 individuals, 79.31  %) presented ocular surface pathologies such as blepharitis or conjunctivitis; the rest did not present any pathology. None of the patients included in the study wore contact lenses. The collected samples were cultured in 2  % non-nutrient agar plates and positive plates were then cultured in axenic conditions for further analyses. Molecular analysis classified all isolated strains as belonging to Acanthamoeba genotype tbl4, and osmotolerance and thermotolerance assays revealed that all strains were potentially pathogenic. Furthermore, all strains were assayed for sensitivity against voriconazole and chlorhexidine. Assays showed that both drugs were active against the tested strains. In conclusion, the Schirmer strip test is proposed as an effective tool for the detection of Acanthamoeba on the ocular surface.