The Laboratorian - Volume 4, Issue 1

The Laboratorian - Volume 4, Issue 1
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July 2012 - Volume 4, Issue 1

Article Index

- SCID Screening
- Chagas Disease
- BSL-3 Training


This issue marks three years of publication for The Laboratorian. It’s funny how important public health projects come back around. One year ago, my editorial focused on the Laboratory Newborn Screening (NBS) program, highlighting how we continue to work on "Improving Health Outcomes for Children." Our NBS Laboratory — already the largest testing volume NBS program in the world — is adding another test to the current panel of 28 disorders. In 2011, we received 741,650 specimens, which is about 62,000 per month or 2,456 per work day. With the addition of Severe Combined Immunodeficiency (SCID) to the screening panel in Fall 2012, each newborn in Texas will be screened twice for 29 disorders. For more details, read the article on "SCID Coming Soon to Texas Newborn Screening Panel" in this issue.

I regularly lead Laboratory tours for new employees. Without question, the most visually interesting stop is the Parasitology Laboratory where various organisms are displayed in conjunction with fascinating stories by Team Lead Cathy Snider. Read the article on "Chagas Disease and Laboratory Diagnosis" to join in our show and tell.

Each year the Laboratory’s Emergency Preparedness Branch opens its doors to host Biosafety Level 3 (BSL-3) Training for members of the Laboratory Response Network. Read the article on "BSL-3 Students Learn to Work Safely" to understand the stringent training — from personal protective equipment to emergency procedures — needed to work in a BSL-3 laboratory. Despite my fascination with virology and this kind of high-security laboratory, I’m content to forego this as a tour stop. Here in the DSHS Laboratory, we take safety seriously.

by Jimi Ripley-Black

SCID Coming in Fall to Texas Newborn Screening Panel

A baby boy born in 1912 had a life expectancy of less than 50 years. A baby boy born in 2012 may live beyond the age of 70. Even today, a baby boy born with a rare genetic disorder known as Severe Combined Immunodeficiency (SCID) may not live past the first year, unless the disorder is identified and treatment started before symptoms occur. Achieving the longevity of his peers requires early detection. With treatment, he may go on to live a long and healthy life.

Texas is one step closer to helping babies born with SCID. In a May 2012 news release, the Texas Department of State Health Services (DSHS) announced that SCID will be added to the Texas Newborn Screening Panel in the Fall of 2012. The same newborn screening specimens currently collected and tested for 28 other disorders will be used to screen for SCID at 24-48 hours of age and 1-2 weeks of age, allowing the earliest opportunity for detection of the disorder. It is estimated that 1 in every 40,000 to 100,000 births each year have classical SCID — sometimes referred to as the “bubble boy” disease. This means that in Texas, four to 10 babies born each year are likely to have SCID and — if not detected and treated — those infants would probably die within the first year of life.

Laboratiran using a multipipette for NBS

Certain mutations in genes cause SCID. Most of these mutations are sporadic with no existing family history (1). SCID is one of the most serious and life-threatening immune disorders; however, it can be successfully treated. Early screening within the first few months of life is important; often babies born with SCID appear healthy. Diagnosis is not made until reoccurring, persistent infections that do not respond to medical treatment raise suspicions. A baby with SCID lacks the white blood cells (lymphocytes) to fight off infections. They have no immune system to build up with exposure to infections. Severe illnesses may begin between the ages of three to six months when maternally derived antibodies — transferred from the mother through the placenta — begin to wane. Infections can become severe and develop into conditions like pneumonia or meningitis, which eventually lead to death. Treatment is initially achieved by keeping the baby away from sick people and crowds, use of antibiotics and, ultimately, a hematopoietic stem cell transplant or enzyme replacement therapy.

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 recommended newborn screening tests. From October 2010 to March 2012, the Texas Newborn Screening (NBS) program SCID pilot study screened samples from children whose parents provided consent for the molecular-based test. The pilot study was completed with one abnormal result found. Although the infant with the abnormal result was not diagnosed with SCID, another genetic disorder was identified. Rachel Lee, PhD, Biochemistry and Genetics Branch Manager, was excited that early identification lead to treatment. “This one was identified early and the mom was relieved,” she said.

According to Dr. Lee, much has to be done to prepare for statewide SCID testing. Preparation is being initiated via conference calls and meetings with immunologists and stake holders. Educational modules are being developed to inform providers about SCID. Equipment, furniture and testing chemicals are being purchased, and a building retrofit is in process to accommodate new instruments, prevent cross-contamination and create space for staff needed for screening. Eight full-time Laboratory employees will be added, and temporary employees have been hired to help implement SCID testing quickly. The Laboratory information management system will also be updated and tested before the first SCID results can be released.

Once SCID testing starts, specimens with repeated positive results will be immediately forwarded to the NBS Program Clinical Care Coordination (CCC) team who will contact the child’s primary care provider (PCP) and send them a SCID information packet that includes an ACT (action) sheet with information on immediate next steps and confirmatory tests, a FACT sheet with parent information, and a list of immunologists in their region. If the additional testing by an immunologist confirms SCID, recommended treatments such as a hematopoietic stem cell transplant or enzyme replacement therapy should be done as soon as possible.

Photo of Cameron and older brother

Jennifer Garcia, a determined and dedicated mother, and now an advocate for SCID awareness and screening, served a key role in the implementation of SCID testing in Texas. On January 4, 2012, Jennifer spoke to the Newborn Screening Laboratory staff at the Texas Department of State Health Services, sharing her own personal story. On March 30, 2011, at the age of nine month, Jennifer’s son Cameron succumbed to pneumonia — the result of an infection that settled in his chest before he was diagnosed with SCID. For more information, read “A Story of Life, Loss, and Advocacy.” Jennifer taught us how a parent suffers if their baby is not screened, diagnosed, and treated in time,” said Dr. Lee.

Jennifer’s advocacy for SCID screening has reached hospitals, legislators, parents and the DSHS Newborn Screening program. She participated as a DSHS volunteer during the pilot study by educating providers about the disorder and how to obtain consent from parents.

NBS laboratorians and CCC staff may never meet the babies they screen and follow-up, but they will have made a difference in their lives through the testing they perform every day. According to Dr. Lee, “This is lifesaving. This is why we are here doing newborn screening. SCID is the only disorder on the NBS panel that has a possible cure — not just a treatment to slow the progress of the disorder or a dietary modification. There is a treatment, and the baby can be healthy.”

(1) Jeffrey Norris “Newborn Screening for Deadly Immune Disorder SCID Possible Due to UCSF Research

by Lucindra "Cindy" Corrigan 

Chagas Disease and Laboratory Diagnosis

Photos of Chagas vectors and disease

The impact of Chagas Disease has been likened to that of HIV/AIDS in the early days of that epidemic. The comparison was made in an intentionally provocative editorial that appeared in the online journal, PLoS Neglected Tropical Disease, titled "Chagas Disease: The New HIV/AIDS of the Americas."

Chagas Disease is caused by Trypanosoma cruzi, a protozoan of the order Kinetoplastida, which also includes the causative agents of African Sleeping Sickness and Leishmaniasis. It is endemic to the American continents below latitude 40 degrees N. This region includes the southern tier of the United States (US); however, most human cases in this country are patients who immigrate from countries in Latin America. The life cycle of the organism in the US is primarily enzootic, circulating in a number of reservoir animal hosts. In other parts of the world, immigration patterns have contributed to the appearance of Chagas Disease in entirely non-endemic areas. Chagas Disease has gone global.

Chagas Disease transmission is primary vector-borne by an insect of the family Reduviidae, usually Triatoma or Rhodnius species. Common names for these insects include cone-nosed bugs, kissing bugs and assassin bugs. Triatomine bugs prey on their hosts for blood meals, usually nocturnally, with a relatively painless bite. The cracked mud walls and thatched roofs of poor rural communities in Latin America are an ideal habitat for the bugs, where they emerge at night to feed on the sleeping human inhabitants. Interestingly, the infective trypanosome is not transmitted by the bite itself, as it is for organisms that live in the salivary glands of their insect vectors. T. cruzi lives in the hind-gut of its vector and is shed in the insect's feces. Exposure of the bite wound or mucous membranes to this infectious fecal material permits the trypanosome to enter the human host and cause Chagas Disease.

The trypanosome that causes Chagas Disease can also be transmitted congenitally, so the child of an infected mother is at risk. Approximately 5-10 percent of infected women pass the infection to their babies. Chagas Disease is also transmitted effectively through blood transfusions and organ transplants. This route of transmission is of growing concern and is the cause of increased screening efforts in blood and tissue centers. A minor but important transmission route is through the ingestion of food contaminated by insect vectors. There have been significant outbreaks of acute Chagas Disease associated with the ingestion of fresh sugar cane, acai berries, and guava juice in Brazil and Venezuela.

The progression of Chagas Disease starts with an incubation period of one to two weeks. This period may be asymptomatic or characterized by fever. Some patients will display inflammation at the site of inoculation (chagoma) or unilateral swelling of the upper and lower eyelids (Romana's sign). Only about one percent of patients present with severe acute disease, which may include myocarditis, pericardial effusion and meningoencephalitis. Severe acute disease is more frequent with transmission through contaminated food; this may be dose related. After 8-12 weeks, the acute infection transitions into an asymptomatic indeterminate phase that may last decades before clinically apparent chronic disease develops in 20-30 percent of infected persons.

Chronic Chagas Disease is characterized by cardiomyopathy in the cardiac form and pathology of the esophagus and colon in the digestive form. Chagas Disease may also exhibit mixed cardiac and digestive symptoms. In immune compromised patients, neurological symptoms may also manifest.

Chagas Disease, or American Trypanosomiasis, was first described in 1909 by Dr. Carlos Chagas, a Brazilian clinician and scientist who isolated its etiological agent, discovered its vector and worked out the salient features of its epidemiology. It was then, and still is, a significant source of morbidity and mortality in Latin America. The World Health Organization (WHO) estimates that 10 million people are infected globally, most in Central and South America. Chagas ranks highest among the parasitic diseases in the Americas, where it causes five times the death and disability of malaria.

Photo of Dr. Chagas in his lab

The DSHS Laboratory works closely with the Centers for Disease Control and Prevention to route specimens for Chagas Disease testing to the CDC Laboratory. It is CDC policy to laboratory confirm a diagnosis themselves before releasing antiparasitic medications to treating physicians. This is in compliance with the investigational drug use protocols. Recent attention to Chagas Disease has increased the number of specimens submitted to DSHS for routing to CDC, and hopefully that will mean more asymptomatic blood donors who test serologically positive have the opportunity for treatment before infection with Trypanosoma cruzi develops into serious disease.

Laboratory diagnosis is made microscopically during the acute phase of Chagas Disease. Circulating trypomastigotes in the peripheral bloodstream can be detected on a giemsa stained peripheral smear or by molecular methods. Once the infection enters the chronic phase, characterized by amastigotes in smooth muscle tissue, serological testing is more useful. Routinely, an Enzyme Immuno Assay (EIA) test is used for screening purposes, which is then confirmed by Immuno Fluorescence Assay (IFA) or Radio Immuno Precipitation Assay (RIPA) tests. Chronic disease is usually diagnosed based on symptoms and patient history. An abnormal electrocardiogram, apparent heart enlargement on a chest radiograph and signs of congestive heart failure may prompt serological testing for T. cruzi. This testing may also be indicated when barium contrast studies of the esophagus and colon display abnormalities.

Chagas Disease prevention strategies vary in the developing and the developed world. In developing countries, prevention includes application of insecticide in houses and surrounding areas, house improvements to prevent infestation, personal preventative measures like bed-nets, and good hygiene practices in food preparation. Early diagnosis is also accomplished via the screening of newborns of infected mothers and siblings of infected children. In developed countries, the security of the blood and tissue supply is of crucial importance. Cases of Chagas Disease transmission have occurred not only in blood transfusions, but also in organ transplants of the kidney, pancreas, liver and heart. Estimates vary, but probably 90 percent of the U.S. blood supply is serologically screened for Chagas Disease. However, screening is not mandated by law.

Chagas Disease treatment options are currently very limited. Two antiparasitic medications are used:  benznidazole and nifurtimox. Both medications are contraindicated by pregnancy and renal or hepatic failure, and their side effects are common and more severe with increasing age. In the U.S., these medications are only available through CDC under investigational drug use protocols. Antiparasitic treatment is indicated for all acute, congenital and reactivated Chagas Disease. It is indicated for chronic disease in children up to 18 years of age. Treatment is also recommended for adults up to 50 years of age without advanced cardiomyopathy. Treatment for chronic disease in adults over 50 should be individualized, weighing the benefits and risks for the patient.

by Cathy Snyder 

BSL-3 Students Learn to Work Safely

The Emergency Preparedness Branch (EPB) of the Laboratory Services Section hosted its third annual Biosafety Level 3 (BSL-3) training course on May 9-12, 2012. A BSL-3 laboratory works with agents that may cause serious or severe illness and have the potential to be spread through respiratory transmission. The EPB has leveraged the professional and subject matter expertise from previous training to develop a multi-faceted BSL-3 training course. This course satisfies the Select Agent Regulation 42CFR training requirement for individuals who work in BSL-3 environments and was primarily developed for members of the Texas Laboratory Response Network (LRN). This free program emphasizes biosafety and biosecurity procedures that are unique to and critical for personnel who work in a BSL-3 laboratory environment. The objectives of the BSL-3 training are to:

Photo of BSL-3 Training participant

  • Demonstrate an understanding of laboratory design and the qualitative differences in biosafety levels;
  • Discuss biosafety cabinet (BSC) design and proper techniques for operating within a BSC;
  • Describe the various types of personal protective equipment (PPE) used in a BSL-3 environment and successfully demonstrate its proper use;
  • Discuss requirements and regulations of the select agent program; and
  • Demonstrate a broad understanding of emergency procedures for the BSL-3 laboratory environment.

The BSL-3 course is comprised of CD-based computer training, developed in-house by the EPB, and a practical portion in the BSL-3 laboratory. The students take the CD-based training prior to arrival at the DSHS Laboratory. Day one is a full day that opens with attendees taking the first in a series of hand written assessments. The lecture portion of the course follows and includes exercises. This covers all biosafety levels (1-4), differences between biosafety and biosecurity, BSC and laboratory design, and regulations involved in maintaining a BSL-3 laboratory. The remainder of the first day and the entire second day are spent hands-on in the laboratory, where participants put the theory into practice.

Training participants are taught to operate at the highest level of of safety using proper personal protective equipment required in a BSL-3 laboratory. In the first activity, students must learn and recite the 21 steps involved in the donning and doffing procedure. These 21 steps teach the proper techniques to put on and carefully remove the protective suit.

Only after they are properly geared do they enter the laboratory. At this time, students see how the BSC operates and offers protection; they see what happens if it fails to work properly. They also practice emergency drills. Participants learn how to safely clean a spill and report the incident. They learn what to do in the case of a “man down” situation. Students also learn best practices in the event of a natural disaster affecting the laboratory and potentially causing a power failure. Some of these scenarios are not typically encountered when working in the BSL-3; however, familiarty is important in order to respond appropriately in an emergency.

A new member of the Biothreat Team, Wanda Songy, attended this training and said “I thought the BSL-3 training was intense but effective. We covered the most important practical points that need to be thought about daily while working in BSL-3, including the donning and doffing procedures, as well as the more administrative tasks, including how written SOPs and even access to this building are all part of biosafety. It was hard work, but I think, as a student and a new person to the BSL-3 lab, I got a lot out of it.”

Learning the proper techniques, skills and safety practices needed to work with infectious agents helps protect the personnel and the surrounding environment from exposure. Participants from around the state of Texas take what they have learned and apply the skills and knowledge in their own laboratory. With hard work and coordination from the Biothreat Team and the Emergency Preparedness Branch, the BSL-3 training has been a success.

by Vanessa Telles 

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July 2012, Volume Four, Issue One                          (Publication #E14-13156)
Published by DSHS Laboratory Services Section
PO Box 149347, MC 1947
Austin, TX 78714

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Grace Kubin, PhD
512 458 7318
email Grace

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

Last updated July 20, 2012