The Laboratorian - Volume 2, Issue 2

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The Laboratorian - Volume 2, Issue 2
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October 2010 - Volume 2, Issue 2

Article Index

- SCID Pilot Study
- Medical Parasitology
- Chemistry at WHL

Editorial

Based on results from a spring onsite inspection, the DSHS Laboratory in Austin, Texas has been awarded accreditation by the College of American Pathologists (CAP). The CAP Laboratory Accreditation Program, begun in 1960, is recognized by the federal government as being equal to or more stringent than the government’s own inspection program.

The CAP accreditation award validates the remarkable two-year effort of laboratory staff in partnership with many support personnel and coordinated by the Quality Assurance group. Staff had to become familiar with CAP checklists and implement a number of changes.

During the CAP accreditation process, inspectors examine the laboratory’s records and quality control procedures for the preceding two years. CAP inspectors also examine laboratory staff qualifications, as well as the laboratory’s equipment, facilities, safety program, and records, in addition to the overall management of the laboratory. This stringent inspection program is designed to specifically ensure the highest standard of care in testing.

The Laboratory Services Section (LSS) can trace its roots back to 1896 when the State Health Officer requested the establishment of two laboratory positions: a State Chemist and State Bacteriologist. Testing was in the area of forensic medicine, water quality checks, and malaria. Today, the LSS is comprised of the Women’s Health Laboratory (San Antonio, Texas), South Texas Laboratory (Harlingen, Texas), and the Central Laboratory (Austin, Texas). The Central laboratory boasts the largest testing volume Public Health Laboratory in the United States and the largest testing volume Newborn Screening Program in the world.

by Sean Chaderton, Quality Assurance Officer

 

Did you know?

On May 4, 2009, the Laboratory received a record 1,410 influenza specimens.


NBS Begins Pilot Study Testing for Severe Combined Immunodeficiency Disorder

New baby sleeping safely in dad's hands

The DSHS Newborn Screening Laboratory is currently conducting a pilot study for Severe Combined Immunodeficiency (SCID) newborn screening, in preparation for the possible future addition of SCID to the Texas Newborn Screening (NBS) Panel.

SCID is a group of disorders characterized by a dysfunctional immune system. Infants with SCID develop recurrent infections, leading to death in early childhood. The incidence of SCID is estimated to be one in 100,000 newborns; however, some studies estimate that the actual number is closer to one in 40,000. Treatment in the first months of life can prevent mortality. Currently available definitive treatments include hematopoietic stem cell transplant and enzyme replacement therapy (available only for adenosine deaminase deficiency). There are studies underway to evaluate gene therapy for some of the conditions.

If infants are diagnosed promptly and treated before the onset of severe infections, the survival rate is reported to be around 95 percent. In contrast, the survival rate is 44 percent in SCID patients diagnosed and treated after the onset of infections. Most babies do not survive beyond one year of age if only supportive management is given. Wisconsin and Massachusetts both implemented cost-effective methods for universal newborn screening for SCID. 

The Texas Newborn Screening (NBS) Program currently screens every
nbsBSpunch

infant born in Texas for 29 disorders, including hearing loss. Early detection and management of these disorders helps prevent mortality and morbidity as well as intellectual disability and other catastrophic health problems in affected babies. As babies with SCID appear normal at birth, SCID holds promise as an ideal condition for population-based newborn screening.

 

On May 21, 2010, the Secretary of the U.S. Department of Health and Human Services approved the addition of SCID to the list of screening tests that all children are recommended to get at birth, based on a recommendation from The Secretary’s Advisory Committee on Heritable Disorders in Newborns and Children.

The Texas NBS Program study aims to evaluate, validate, and implement pilot SCID newborn screening tests and algorithms for identification of infants with SCID, in collaboration with New England Newborn Screening Program (NENSP) and with grant support from the Centers for Disease Control and Prevention (CDC). The tests will be performed using the specimens collected for routine newborn screening in Texas. No additional blood or dried blood spots will be needed for this study. Parental informed consent will be obtained for participation in the pilot study and will occur before the parents/newborns are released from the hospital/birthing facility.

If a positive result is found on the newborn screens, the infant’s primary care provider and a pediatric immunologist will be notified with a recommendation for a referral to immunology to obtain a diagnostic evaluation.

This SCID pilot study provides important information that will complement the screening data from studies conducted by the states of Massachusetts and Wisconsin. Study results will also help determine the optimum testing methodology for SCID to be added to the Texas newborn screening panel when funding in available. Ongoing research is critical to the future development of newborn screening services.

by Sharon Newcomb-Kase, Debra Freedenberg, MD, PhD, and David Martinez 


Medical Parasitology Laboratory

The DSHS Laboratory houses many interesting testing areas, but one of the most visually fascinating is the Medical Parasitology Laboratory. Library shelves exhibit a wealth of disparate glass jars in which float preserved parasites, even more varied in appearance, and laboratory benches support several light microscopes with digital displays.

Though any disease-causing microorganism might be called a parasite, the organisms that are

Parasitology team member using a light microscope
usually referred to as parasites are helminths (worms) and protozoa. Most of these parasites are intestinal pathogens that primarily enter their hosts through ingestion or skin penetration. Both routes require exposure to infective forms, either in feces or encysted in the tissue of animals or plants. Helminths and protozoa have complex life cycles, which are critical to our understanding of these organisms and our knowledge on prevention and control of human infection.

Preserved samples for parasitology visual reference library Parasitology concentration procedure Parasitology concentration procedure: sample filtration

Laboratory diagnosis of intestinal parasites involves the examination of fecal specimens. Feces are collected in special two-vial kits, which are then processed for microscopic examination. The first specimen vial undergoes a concentration process to increase the chances of detecting parasites present in low numbers. This process also removes fecal fat and debris to make visualization easier when the concentrated specimen is examined as a wet mount. Microscopic examination involves a scan for worm eggs or larvae with a 10X objective, and another scan with the 50X oil objective for protozoan cysts. The second specimen vial is used to prepare a stained smear. Feces are rolled onto a slide and then stained using Wheatley's trichrome method. This smear is scanned at a higher magnification, with the 100X oil objective. The trichrome stain helps visualize the fine internal structure of protozoan trophozoite forms. These details of structure help technologists properly identify particular parasites sharing a similar appearance. Occasionally, adult helminths are passed in feces. These worms are macroscopically visible, but to visualize their distinctive morphological features, they are examined under a dissecting microscope.

Digital capture image of hookworm species

"Over 90 percent of the specimens received by the Parasitology Team are submitted by the Texas Refugee Health Program," said Team Lead, Cathy Snider. "These patients are coming to Texas from situations where parasite transmission is very likely—crowded conditions without adequate sanitation systems." Not surprisingly, most of these specimens test positive for the presence of parasites and usually contain multiple species.

In addition to supporting the Refugee Health Program, the Parasitology Team functions as the parasitology reference laboratory for the state of Texas. Reference specimens include feces for intestinal ova and parasite (O&P) examination as well as other tissue and body fluids for extra-intestinal infections. Most often, these are blood specimens to be tested for vector-borne parasites like malaria.

The path to identifying these endoparasites is a lengthy one. By its nature, traditional parasitology testing is a time intensive practice. Helminth eggs and protozoa are visually identified microscopically, distinguished by size and morphology. This is wholly dependent on the pattern-recognition skills of a trained technologist with well prepared specimens and a good

Digital capture image of Trischuris trichura

microscope. DSHS Parasitology Team members spend most of their workday at the scope using the most sophisticated instruments in the laboratory—their brains.

The origin of the word parasite comes from the Greek παράσιτος, pronounced parasitos, liberally translated as “one who eats at another’s table” and literally translated as “beside food.” While not all parasites will dwell in your food, the idea that your mouth and digestive tract are a main factor in the life cycle of human parasitic infections is one to note. Mug shots of eight unique parasites can be viewed on the Medical Parasitology web page on medically important parasites.

by Monty Gomez

 

Action and Reaction: Chemistry at WHL

Photo of a chemistry technologist at work on a Beckman Coulter DXC600 Chemistry Analyzer

Women’s Health Laboratory (WHL) analyzes 50 of the most critical chemistry components to aid in the treatment of patients in Texas. This analysis provides valuable information for diagnosis and treatment of disease.

Five Chemistry technologists bring a total of 134 years of experience to the testing of specimens. The team work is extensive—from STAT (urgent or rush) testing to routine testing and

monitoring patient maintenance—staff at WHL work together to provide accurate and precise results to submitters.

Outside of normal business hours, WHL maintains a 24/7 On-Call technologist to manage STAT testing, phlebotomy, and emergency consultation for the Texas Center for Infectious Disease Tuberculosis hospital, San Antonio State Hospital, and San Antonio State Supported Living Center, which are all located on the same campus.

Most Chemistry tests have a 48-hour turnaround time, but 90 percent are reported within six hours of sample arrival at the lab. STAT samples have a stated turn-around time of two hours, and currently the average is just over 46 minutes from receipt to report. All critical values are reported immediately to the designated staff at the submitting facility.

A clinician can order single Chemistry tests or multi-test panels. The test menu encompasses endocrinology, cardiac enzymes, liver function, electrolytes, lipids, therapeutic drugs, urine chemistries, iron metabolism, thyroid function, metabolic function, glucose tolerance, drugs of abuse, and customized admission panels. The full menu of tests can be obtained by calling the WHL customer service department at (888) 440-5002.

by Cynthia Dennis

 


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THE LABORATORIAN
October 2010, Volume Two, Issue Two
(Publication #E14-13156)
Published by DSHS Laboratory Services Section
PO Box 149347, MC 1947
Austin, TX 78714

512 458 7318
888 963 7111, ext 7318 Toll Free
email The Laboratorian

 

LABORATORY DIRECTOR
Susan U. Neill, PhD
512 458 7318
email Susan

NEWSLETTER EDITOR
Jimi Ripley-Black
512 458 7318, ext 6505
email Jimi

Last updated April 06, 2011