Blood Bank Case Study: “Oh I’m so confused! What type am I?” Weak D Phenotypes in Pregnant Women

In my July post, “Blood Bank Case Study: What’s Your Type?” I discussed some of the dilemmas when dealing with a weak D phenotype and the fact that there is no standard or general consensus as to the testing performed or terminology to be used in resulting a weak D patient. Results obtained on patient testing also vary depending on the method used, and the anti-D reagent and enhancement used in testing. This can be confusing to medical technologists, physicians and to patients.

For anyone who has not been in the Blood bank for a while, the Du variant was first recognized in 1946 and renamed weak D in 1992. To review last month’s blog, serologic studies have distinguished three broad categories of D variants, weak D, partial D, and DEL, from conventional D. A serologic weak D phenotype is one that has no or weak reactivity (≤2+) of RBCs with an anti‐D reagent at immediate spin, but does agglutinate with antihuman globulin. Since there is no general consensus on how labs perform and report patient testing for weak D, it is left up to individual interpretation as to what type blood these patients should receive, and, if pregnant, if they should receive Rh D immune globulin (Rhogam). Last month I focused on testing, resulting, donors and blood administration. In this blog I will focus on issues concerning weak D in the obstetric population and how labs can move forward now and in the future towards the best patient care and blood management.

About 15% of Caucasians are RhD negative. About 3% are weak D phenotypes.In the genral population, this means that about 0.2% to 1.0% inherit RHD genes that code for serologic weak D phenotypes.2 In Europe and the US, weak D phenotypes are the most common D variants found, but we also know that the prevalence of weak D phenotypes varies by race and ethnicity. Today we have much more information about D antigen expression than we had in the past, because we have the availability to genotype these weak D RBCs. We know that more than 84 weak D types have been identified, but types 1, 2, and 3 account for more than 90% of these in people of European ethnicity.1  Currently, with the mixed ethnicity population in the US, about 80% of people who inherit RHD genes for serologic weak D phenotypes are found to be weak D type 1, 2, or 3.3 We also know that types 1, 2 and 3 are unlikely to become alloimmunized to anti-D, so they can safely be treated as RhD positive and receive RhD positive units.

The introduction of RhD immune globulin in 1968 is one of the great success stories in obstetrics. Rhogam has been used very successfully in developed countries in the prevention and treatment of hemolytic disease of the fetus and newborn due to RhD alloimmunization. The routine recommendation is that women who are candidates for Rhogam receive one dose at approximately 28 weeks’ gestation and a second dose after the delivery of an Rh pos baby. Additional recommendations are for administration of Rhogam after threatened miscarriage, abdominal trauma during pregnancy and before invasive diagnostic procedures.

But, who is a candidate? Any unsensitized woman who is RhD negative and who may be carrying or who delivers an RhD positive baby is a candidate for Rhogam. And, that brings us back to the problem that we have no standardization for the reporting of serological weak D phenotypes.

As an example, let’s look at a patient who has 3 children. Many labs do not do weak D testing on patients and report anyone who is RhD negative at immediate spin as RhD negative. This patient was typed at such a lab (Lab #1) as RhD negative, and received Rhogam for her first pregnancy. During her 2nd pregnancy, she had moved to a different state, and went to another lab (Lab #2) for prenatal testing. This lab performed serologic weak D testing and found this patient to be weak D positive and reported her type as RhD positive. Rhogam was not further discussed during this pregnancy and the patient did not receive Rhogam. The patient had blood drawn during her 3rd pregnancy at yet a third hospital (Lab #3). Some labs distinguish women who are pregnant or of childbearing age from the general population, and have different procedures on the reporting of RhD type on these women. This hospital’s procedure was to do weak D testing on all patients, but, in women of childbearing age, if weak D positive, they report these women as RhD negative. The patient was told she was RhD negative and would be a candidate for Rhogam. At this time the woman thought she remembered that she didn’t get Rhogam with her second pregnancy and was a little confused, but with 2 young children and pregnant with her 3rd, she simply followed the doctor’s recommendation and didn’t question further. When her 3rd child was 4 months old, she attended a Red Cross blood drive at work and donated a unit of blood. Soon she received a blood donor card in the mail that said she was RhD positive. At this point she was thoroughly confused and questioned all the lab results she had had done over the past 6 years. On her next visit to the doctor she questioned her obstetrician. The obstetrician recommended RhD genotyping. The woman was found to be weak D type 2. The doctor explained to her that all blood donors who are weak D are treated as RhD positive, but, that as a patient, policies and procedures vary. However, he also informed her that now that they had her genotype, she would be considered RhD positive. He explained that the genotype was DNA testing, would not need to be repeated, she would not need Rhogam for any future pregnancies and she could safely receive RhD positive blood products.

The American College of Obstetricians and Gynecologists (ACOG) guidance practice bulletin of 1981 recommended that recommended that RhD‐negative women “whether Du positive or Du negative” were candidates for Rhogam. Shortly afterwards, that recommendation was reversed and revised to read “[a] woman who is genetically Du‐positive is Rh‐positive and administration of Rh immune globulin is unnecessary.1 This remained the recommendation of the group until the latest version of this publication in 2017. The 2017 ACOG guidelines recommend giving Rhogam to weak D positive patients, “in appropriate clinical situations, until further studies are available.”3 Another comparative study published in 2018 reported inconsistency between national groups over how to treat weak D phenotypes and recommended the creation of international guidelines.4

Thus, the controversy over whether a pregnant woman who is weak D positive is RHD positive or RHD negative continues. The latest recommendations, and those of ACOG, are for a move to genotyping patients with a serological weak D phenotype. There are several benefits to this. As we can see from my case study example, genotyping put this woman at ease and gave her definitive answers about her blood type. It also can do the same thing for medical technologists and physicians. RHD genotyping only needs to be performed once on a patient. If performed at the first prenatal appointment, this would alleviate much confusion as to procedures and how to report the results. I have in blood bank, that whenever we have a weak D on a prenatal patient, there are questions about how to result them, and we refer to the SOPs. We also occasionally get a patient who had previously been typed elsewhere where the reporting procedures were different and there is therefore an apparent discrepancy between the current and historical typing. This causes frequent phone calls from physicians and nurses asking for clarifications on weak D types, and questions about Rhogam. Lastly, RHD genotyping could avoid confusion which could lead to transcription and computer entry errors when entering types on these patients. RHD genotyping would solve all of these problems and eliminate confusion.

Additional benefits of RHD genotyping are, if RHD genotyping was performed on all weak D transfusion recipients, we could save as many as 47,700 units of RHD negative RBCs annually.3 With the availabilityof molecular testing, there is no reason to administer RhD negative units to patients who can use RhD positive units. This could help alleviate the constant shortage of RHD negative units. With RHD molecular testing, these critical units could be reserved for patients who are truly RhD negative.

It may not be feasible for all laboratories to perform molecular testing for RHD genotypes, but reference laboratories should offer affordable testing for the most prevalent and clinically relevant RHD genotypes. From a study done of over 3100 laboratories, it was found that, at this time in the US, most labs are managing weak D phenotypes as RhD negative. Laboratories not performing weak D testing are essentially avoiding their detection. Clinical laboratories should instead increase the detection of serological weak D and interpret these with the use of RHD genotyping. Rhogam shortages exists, and RHD genotyping could save thousands of injections of Rhogam annually in the US alone, and at the same time, avoid the unnecessary administration of products to patients. The work group study calculated that annually, approximately 24,700 doses of unnecessary Rhogam could be avoided.1 It is time to move forwards to molecular testing for the best patient care and blood management.


  1. Sandler SG, Flegel, WA, Westhoff CM, et al. It’s time to phase in RHD genotyping for patients with a serologic weak D phenotype. Transfusion 2015;55:680‐9
  2. Garratty G. Do we need to be more concerned about weak D antigens? Transfusion 2005;45:1547‐1551.
  3. Practice Bulletin No. 181: Prevention of Rh D AlloimmunizationObstetrics & Gynecology: August 2017 – Volume 130 – Issue 2 – p e57-e70 doi: 10.1097/AOG.0000000000002232
  4. Sperling, JD et al. Prevention of RhD Alloimmunization: A Comparison of Four National Guidelines. Am J Perinatol. 35(2):110-119. doi: 10.1055/s-0037-1606609. Epub 2017 Sep 14.

-Becky Socha, MS, MLS(ASCP)CM BB CM graduated from Merrimack College in N. Andover, Massachusetts with a BS in Medical Technology and completed her MS in Clinical Laboratory Sciences at the University of Massachusetts, Lowell. She has worked as a Medical Technologist for over 30 years. She’s worked in all areas of the clinical laboratory, but has a special interest in Hematology and Blood Banking. When she’s not busy being a mad scientist, she can be found outside riding her bicycle.

Microbiology Case Study: A 57 Year Old Man with Fever

Case History

A 57 year old male with a recent history of a left above the knee amputation developed a fever during the same admission of 101.1°F. His amputation had been complicated by poor wound healing, and he had a simultaneous right leg abscess that grew methicillin-sensitive Staphylococcus aureus. Examination of his wound showed serosanguinous drainage with no erythema or purulence. Blood cultures and a wound swab were sent for microbiological analysis.

Laboratory Findings Wound cultures grew methicillin-resistant Staphyloccocus aureus thought to represent colonization rather than true infection. Blood cultures flagged positive in one anaerobic bottle only at 30 hours. A gram smear showed gram-negative cocci (Image 1). Anaerobic blood plates grew pinpoint colonies (Image 2). MALDI-TOF identified the bacteria as a Veillonella species.

Image 1. Gram stain from anaerobic culture showing gram negative cocci.
Image 2. Growth on anaerobic blood plate.


Veillonella species are gram negative cocci. They are lactate fermenting, obligate anaerobes and are considered normal flora of the intestines and oral mucosa. As such, they are usually regarded as a contaminant. They have, however, been implicated in osteomyelitis, prosthesis infections, and endocarditis. They are particularly associated with poor oral hygiene, chronic periodontitis, and smoking. They have important implications in dental disease due to their ability to form biofilms. They are frequently resistant to ampicillin and have also been noted to be resistant to tetracyclines in periodontal patients. Identification is done by molecular methods, typically MALDI-TOF. PCR has also been developed, but is not routinely used.

This was considered a contamination due the absence of symptoms and isolation in one bottle only. A follow up blood culture was negative. Routine wound care was resumed.


  1. Rovery C, Etienne A, Foucault C, Berger P, Brouqui P. Veillonella montpellierensis endocarditis. Emerg Infect Dis. 2005;11(7):1112–1114.
  2. Mashima I, Theodorea CF, Thaweboon B, Thaweboon S, Nakazawa F. Identification of Veillonella Species in the Tongue Biofilm by Using a Novel One-Step Polymerase Chain Reaction Method. PLoS One. 2016;11(6):e0157516. Published 2016 Jun 21.

-Jonathan Wilcock, MD is a 1st year anatomic and clinical pathology resident at the University of Vermont Medical Center.

-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.

Surgical Pathology Case Study: A 6 Year Old Patient with Sudden Onset Abdominal Pain and a Worrisome Mass on Imaging

Case History

The patient is a 6 year old who developed abdominal pain 2 days prior to admission. The patient was in school when the abdominal pain began, resulting in the patient doubling over in pain. The pain resolved within 1 hour, however, because the initial presentation was an unremitting abdominal pain, the patient was taken to an outside hospital for evaluation. There was no vomiting, diarrhea, or constipation. On physical exam, the patient was very tender to palpation in the right lower quadrant and was unable to tolerate deep palpation. A computed tomography scan was subsequently ordered which showed a large mass in the pelvic peritoneum. The patient was admitted to surgery for an exploratory laparotomy, with resection of the pelvic mass.


Received fresh in the Surgical Pathology laboratory is a 162.5 gm, 10.2 x 7.5 x 4.0 cm lobulated, ovoid mass of pink-tan, rubbery tissue that appears encapsulated by a thin translucent membrane. The margins are inked black and the specimen is serially sectioned revealing glistening, gray-tan soft tissue with focal areas of yellow discoloration and softening. Along one edge of the specimen, there is a 4.0 x 1.5 cm rim of dark red-brown, rubbery tissue (Figure 1). Portions of the fresh specimen are submitted in glutaraldehyde for electron microscopy if needed, RPMI for cytogenetics, and are snap-frozen as well. Touch preparations are also made and gross photographs are taken. Representative sections are submitted as follows:

Cassette 1-7:    Sections of mass including inked capsule

Cassette 8-10:   Representative sections from central portion of mass including areas of softening and discoloration

Cassette 11-13: Additional representative sections of the mass

Image 1. Cut surface of a gray-tan mass with yellow areas of discoloration and hemorrhage around periphery.

Histologically, the mass is composed of sheets and nests of small round cells along thin fibrous septa, giant multinucleated cells, and rare strap cells. Necrosis less than 5%. The margins are positive, although the specimen is unoriented. Venous and lymphatic invasion is absent. Immunohistochemical (IHC) stains are ordered and the results are listed below:

Positive IHC stains: Myogenin, desmin, CD56 and Bcl-2

Negative IHC stains: S-100, keratin AE1/AE3, CAM 5.2, SMA, CD99, Fli-1, WT-1, and EMA

In addition to the IHC stains, a portion of tissue was sent for cytogenetics testing, which showed a chromosomal translocation at t(2;13)(q35;q14). Based on the histologic appearance, IHC stains, and cytogenetic testing, the specimen was signed out as an alveolar rhabdomyosarcoma with a pathologic stageof pT2b, N0, MX.

Following the diagnosis, the patient was placed on a chemotherapy regimen of Vincristine, Adriamycin, Etoposide and Cytoxan, as well as radiation therapy.


Rhabdomyosarcoma is the most common malignant soft tissue tumor in children and is the most common malignant solid tumor in children after neuroblastoma and Wilms tumor, accounting for 5-10% of all childhood tumors. 90% of these tumors occur in patients under the age of 25, and approximately 70% occur in children under 10 years of age. The most common locations of rhabdomyosarcoma are in the head and neck region, followed by the genitourinary system, extremities and then torso.

The 2013 World Health Organization classification of skeletal muscle tumors divided rhabdomyosarcoma into four types based on histology:

  1. Embryonal rhabdomyosarcoma (botryoides and anaplastic variant)
  2. Alveolar rhabdomyosarcoma (solid and anaplastic variant)
  3. Pleomorphic rhabdomyosarcoma
  4. Spindle cell/sclerosing rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) accounts for approximately 20-30% of all rhabdomyosarcoma tumors, with no genetic predisposition. Although it is most common in teenagers, ARMS affects all ages. Most patients will present with a painless soft tissue mass, but based on the size and location of the mass, it may cause mass effect. A quarter of patients will have metastasis at the time of diagnosis, most commonly to the bone marrow, bones, and lymph nodes.

Grossly, ARMS presents as a solid, well-defined mass with a fleshy, tan-gray cut surface. Histologically, it is composed of small, blue, round cells and occasional round to spindle shaped rhabdomyoblasts. When compared to embryonal rhabdomyosarcoma, the rhabdomyoblasts in ARMS are slightly larger. ARMS is broken down into two subtypes: the classic subtype and the solid subtype. In the classic subtype, the tumor is composed of nests of cells that adhere to the edges of fibrous septa, resembling pulmonary alveoli (hence the name alveolar rhabdomyosarcoma). Multinucleated giant cells with a peripherally located nuclei may also be present. In the solid subtype, there will be nests and sheets of neoplastic cells that are separated by thin fibrovascular septa, but will not form in the classic alveolar pattern (Image 2).

Image 2. 20x photomicrograph demonstrating the neoplastic cells lining up along thin fibrous septa, giving the appearance of pulmonary alveoli

Due to the various appearances of rhabdomyosarcoma, it has become important to integrate immunohistochemical (IHC) stains and molecular testing into the diagnosis. The most common IHC stains that are used to determine the rhabdomyoblastic differentiation of a sarcoma is through the use of Myogenin and Myogenic differentiation 1 (MyoD1) stains, in which both stains will be positive in rhabdomyosarcoma. These two stains can be furthered used to help narrow down a diagnosis of ARMS because if more than 50% of the neoplastic cells express Myogenin, this is highly suggestive of a diagnosis of ARMS (Figure 3). In ARMS, the MyoD1 will have a variable expression. Additional positive IHC stains for ARMS can include: desmin, P-cadherin, and bcl-2.

Image 3. Myogenin IHC stain demonstrating a strong, homogenous expression

To go along with IHC stains, molecular testing has been shown to be affective with determining the type of rhabdomyosarcoma. There have been two translocations that have been identified in ARMS. The first is at t(2;13)(q35;q14), which results in a fusion of the PAX3 gene with the FOXO1 gene (previously known as the FKHR gene). This translocation is present in 60% of all ARMS cases, and has been found to occur mostly in older children and younger adults. The second translocation is at t(1;13)(p36;q14), which results in a fusion of the PAX7 gene with FOXO1, and is present in approximately 20% of all ARMS cases. The remaining 20% are fusion negative, and are associated with the solid subtype histologically. There is early preliminary data that shows a less aggressive disease course in patients with the PAX7-FOXO1 fusion, compared to those with the PAX3-FOXO1 fusion.

In order to determine the best treatment course, patients who are diagnosed with rhabdomyosarcoma are divided into a low risk, intermediate risk or high risk group based on the pathologic stage, clinical stage and clinical group. The pathologic stage is determined using the Pretreatment TNM Staging System that was set forth by the Intergroup Rhabdomyosarcoma Study (IRS) group (not the same as the TNM staging system put out by the American Joint Committee on Cancer) below:

The clinical stage is then determined using the TNM staging above and the Pretreatment Clinical Staging System below that is also put out by the IRS group:

In the above Clinical Staging System, a favorable site is defined as occurring in the orbit, biliary tract, head and neck region (excluding parameningeal) and genitourinary region (excluding prostate and bladder). Any other site not listed is considered unfavorable. Next, a clinical group is assigned based on the extent of the disease using the Clinical Grouping System below, which again is put out by the IRS group:

Lastly, based on the clinical stage and clinical group determined above, the patient is assigned a risk group of either low risk, intermediate risk, or high risk using the Children’s Oncology Group guidelines listed below:

When compared to embryonal rhabdomyosarcoma, which is the most common type of rhabdomyosarcoma, ARMS has a worst prognosis. The IRS group clinical group and stage can help to predict the overall outcome of the patient, with the standard treatment regimen composed of surgery, radiation therapy and chemotherapy.


  1. Dziuba I, Kurzawa P, Dopierala M, Larque A, Januszkiewicz-Lewandowska D. Rhabdomyosarcoma in Children – Current Pathologic and Molecular Classification. Pol J Pathol. 2018;69(1):20-32. doi:10.5114/pjp.2018.75333
  2. Liu H, Zhao W, Huang M, Zhou X, Gong Y, Lu Y. Alveolar rhabdomyosarcoma of nasopharynx and paranasal sinuses with metastasis to breast in a middle-aged woman: a case report and literature review. Int J Clin Exp Pathol. 2015;8(11):15316–15321. Published 2015 Nov 1.
  3. Owosho AA B Ch D, Huang SC Md, Chen S Mbbs, et al. A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome. Oral Oncol. 2016;61:89–97. doi:10.1016/j.oraloncology.2016.08.017
  4. Ozer E. Alveolar Rhabdomyosarcoma. Pathology Outlines. Revised March 26, 2019. Accessed July 26, 2019.
  5. Rudzinski ER, Anderson JR, Hawkins DS, Skapek SX, Parham DM, Teot LA. The World Health Organization Classification of Skeletal Muscle Tumors in Pediatric Rhabdomyosarcoma: A Report From the Children’s Oncology Group. Arch Pathol Lab Med. 2015;139(10):1281–1287. doi:10.5858/arpa.2014-0475-OA
  6. Rhabdomyosarcoma Staging and Clinical Risk Groups. Stanford Medicine Surgical Pathology Criteria. Accessed August 10, 2019

-Cory Nash is a board certified Pathologists’ Assistant, specializing in surgical and gross pathology. He currently works as a Pathologists’ Assistant at the University of Chicago Medical Center. His job involves the macroscopic examination, dissection and tissue submission of surgical specimens, ranging from biopsies to multi-organ resections. Cory has a special interest in head and neck pathology, as well as bone and soft tissue pathology. Cory can be followed on twitter at @iplaywithorgans.

When Gender Goes Awry in Electronic Health Records

For most people working in laboratory medicine, their first encounter with transgender patients likely arose from an issue involving the Electronic Health Record (HER). For me, I was called into the reference lab, because an abnormally high estradiol result was found by the referring lab. They were concerned this might be coming from a hormone secreting tumor, but inspection of the patient’s record revealed they had been taking higher than recommended doses of their feminizing hormones.

Today I will share stories from issues that arise in EMR when gender doesn’t equal sex. While these may not specifically happen to all of you, I hope they can be informative or help you anticipate future problems.

Transgender issues came up at one of our institutions when providers were getting dozens of messages in their in-baskets about new flagged lab results for multiple patients. This is very annoying, because they have to address each of these messages or they are out of compliance with the hospital. An investigation revealed that all of the patients involved were transgender patients. In order to get estradiol, sold as oral contraception pills, the pharmacy had to administratively change their sex in the EHR for approval, then change it back.

This moved their corresponding reference ranges out of sync, which triggered a new results flag. Changing the sex back triggered other flags and more messages. This was finally resolved after a committee was convened and several meetings occurred, but no one would have anticipated this type of issue arising from a simple action to get patients their medicine.

Sometimes transgender patients have their sex changed legally. If an EHR only includes one sex entry instead of gender and sex assigned at birth, then certain lab errors may prevent processing of important samples. The pregnancy test for a transgender man could be auto-rejected. This can be an issue even for providers in front of the patient as was recently reported in a case to the NEJM about a transman who was mistaken as obese instead of pregnant and miscarried their child.

Similarly, a prostate biopsy from a transgender woman could be auto-rejected by a surgical pathology system as an inappropriate specimen type for the patient. Even further, an EHR could fail to prompt a provider from making a prostate cancer risk assessment in a transgender woman, which could result in improper screening.

I would recommend that EHR includes three separate fields (sex assigned at birth, gender, and legal sex) to fully recognize transgender patients and provide optimal personalized healthcare to them.


  1. Gupta S, Imborek KL, Krasowski MD. Challenges in Transgender Healthcare: The Pathology Perspective. Lab Med. 2016 Aug; 47(3):180-188.
  2.  Stroumsa D, Roberts EFS, Kinnear H, Harris LH. The Power and Limits of Classification – A 32-YearOld Man with Abdominal Pain. N Engl J Med. 2019 May 16;380(20):1885-1888. doi:10.1056/NEJMp1811491.

-Jeff SoRelle, MD is a Chief Resident of Pathology at the University of Texas Southwestern Medical Center in Dallas, TX. His clinical research interests include understanding how the lab intersects with transgender healthcare and improving genetic variant interpretation.

The Disaster Risk Assessment

There are multiple types of risk assessments required when managing a laboratory safety program. OSHA’s Bloodborne and Airborne pathogens standards require assessing the risk of employees’ exposure to particular lab hazards. Risk assessments can be used to determine whether or not to add an emergency eyewash station, and all lab chemicals need to be assessed for the hazards they pose. These are just some assessments that are needed, and there are particular steps to take when performing them. But what about the lab emergency management plan? Should the lab perform a risk assessment for that? The answer is yes, although the terminology used may be different. To prepare a disaster readiness plan for the lab, the risk assessment that is needed is known as a Hazard Vulnerability Analysis (HVA).

The Centers for Medicare & Medicaid Services (CMS) requires that all healthcare facilities use an “all-hazards” approach when considering emergency preparedness and planning. While some laboratories may be included with the facility-wide disaster plan, the lab should absolutely have its own plan with specific instructions that apply directly to the department. That means the lab should also consider an all-hazards approach.

It may seem daunting to try to consider every possible disaster that could occur in the department, but that is not exactly what the directive from CMS dictates. An all-hazards approach means that emergency plans should be scalable or flexible so that it can be used for many types of disasters. The plan should focus on the lab’s ability to continue to offer services, especially those deemed critical, as a disaster situation unfolds.

The first step to the plan creation is the risk assessment- the Hazard Vulnerability Analysis. The HVA can be a table that lists all of the potential types of disaster; natural, man-made, facility-specific, etc. List as many as you can think of, and be sure to include specific disasters that may be particular to your locale (earthquakes, blizzards, etc.). Rate each disaster type by probability, severity of impact, and level of readiness of the lab to respond. Using that data, you can calculate the risk percentage for each emergency type.

One other requirement imposed by CMS is that facilities must include emerging infectious diseases as one potential type of hazard class. With the advent of particular diseases in the past years like Ebola, Zika, and certain influenza types, it is important to consider how an outbreak would affect lab operations and staffing. The risk level of infectious diseases may vary as incidents and outbreaks occur in particular geographic regions or if pandemics arise.

The HVA should be reviewed and updated as necessary each year. Things change that can affect what is on your HVA list. The addition of a nearby airport might make you consider adding airline disaster to the HVA. A change in weather patterns could occur as well. In 2011 a surprise earthquake in Virginia made state facilities re-look at their HVA list of possible emergency situations. Also, the actual list of disasters might not change, but there may be a change in the potential of a particular incident occurring.

If your lab or facility has not yet performed the HVA risk assessment, there is no need to panic. There are several model HVA tools available on line that can be used. As with any risk assessment, be sure to keep documentation readily available, review it each year, and make sure staff are trained about not only the HVA process, but in how to use the emergency management plan as well. There is a great amount of work that can go into preparing for a disaster, and training and drills for your staff will help to facilitate a smoother activation of the plan when the real emergency situation occurs.

Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years experience as a certified medical technologist. Today he is the Laboratory Safety Officer for Sentara Healthcare, a system of seven hospitals and over 20 laboratories and draw sites in the Tidewater area of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.

Microbiology Case Study: An 83 Year Old Male with Fever

Case History

The infectious disease service was consulted on an 83 year old male for fever.

His past medical history was significant for diabetes mellitus, anemia and renal insufficiency. He initially presented 3 weeks ago with chills, rigors and fever to 103 degrees Fahrenheit. For the past several months, the patient has had weight loss (10-20 pounds over an unspecified timeframe), fatigue and new iron deficiency anemia. A heart murmur was heard on physical exam. The patient was admitted for suspicion of sepsis and he was started on empiric antibiotics vancomycin and ceftriaxone. Three sets of blood cultures were drawn prior to initiation of antibiotics, which were all positive for gram positive cocci in pairs and chains. Transesophageal echocardiogram (TEE). TEE showed large vegetation on posterior mitral leaflet measuring 1cm x 1.8 cm, and a smaller mass on the anterior leaflet. A week after admission, a mitral valve replacement was performed followed and a portion of the valve was sent for culture (Figure 1).

Laboratory Identification

Image 1. Gram stain from mitral valve specimen showing a large accumulation of gram positive cocci in chains (100x magnification).
Image 2. Brown-Hopps stain of the surgically resected mitral valve tissue vegetation showing sheets of gram positive bacteria (40x magnification).


The gram positive organism from blood and mitral valve culture was identified as Streptococcus mitis by MALDI-TOF mass spectrometry. S. mitis is a member of the Streptococcus genus. Streptococci have a number of features that aid in laboratory identification: they are Gram positive, catalase-negative, spherical/ovoid, with organisms that are usually found in chains. They are facultative anaerobes.

More specifically, S. mitis belongs to the viridans streptococci group which includes Streptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius, among many others. The most common infection caused by viridans streptococci is bacterial endocarditis, as in the case of this patient. Other infections can include brain abscesses, liver abscesses, dental caries, and bacteremia.

Patients with bacterial endocarditis have an infection of the heart valves or the endoecardial wall that leads to formations of vegetations. These vegetations are composed of thrombotic debris and organisms (Image 2), often associated with destruction of cardiac tissue. Its onset often involves severe symptoms including fever, chills, and weakness. Fever is the most consistent symptom of infective endocarditis, but it may be subtle or even absent in some cases, especially in older adults. Weight loss and flu-like symptoms may also be seen. Left-sided infective endocarditis, as in the case of our patient, will present with murmur in 90% of cases. In long-standing infective endocarditis, patients may present with Roth spots (retinal hemorrhages), Osler nodes (subcutaneous nodules in the digits), microthromboemboli (which appear as splinter hemorrhages under fingernails and toenails), and Janeway lesions (red nontender lesions on the palms or soles).

In the laboratory, the diagnosis of S. mitis and other viridians streptococci is often detected via blood culture as in the case of this patient. Once the blood culture bottle becomes positive, a Gram stain is performed, which shows Gram positive cocci in chains (Image 1). These features are helpful in differentiating Streptococcus from Staphylococcus (which appears as clusters instead of chains). Biochemical testing can be done to narrow down the species and identify S. mitis, which is optochin resistant (as opposed to S. pneumonia), acetoin negative (in contrast to most other viridans organisms), and urease negative (which differentiates it from S. vestibularis which is urease positive).

Surgical pathology can also aid in diagnosis by microscopically identifying vegetations on the affected valve (Image 2). Treatment of bacterial endocarditis is usually with penicillin or ceftriaxone, however susceptibility testing should be performed on S. mitis and other viridians streptococci because resistance can occur to penicillin. Blood cultures are followed until they are negative for 72 hours. In the case of our patient, his cultures became negative shortly after he started treatment. Susceptibility testing showed that the organism is sensitive to penicillin and ceftriaxone. The patient was continued on ceftriaxone and is clinically improving.

-Haytham Hasan, MD, is an Anatomic and Clinical Pathology resident at NorthShore Evanston Hospital (University of Chicago).

-Erin McElvania, PhD, D(ABMM), is the Director of Clinical Microbiology NorthShore University Health System in Evanston, Illinois. Follow Dr. McElvania on twitter @E-McElvania. 

An ASCP Volunteer’s Experience Abroad

I volunteered in April 2019 in Tanzania at the Kilimanjaro Christian Medical Center. I was there specifically to teach breast mastectomy grossing. There are two pathologists at KCMC, Dr. Mremi and Dr. Patrick, but finding time in their schedule to work with them proved to be the biggest challenge. The pathologists have many responsibilities outside of just looking at slides. Dr. Alex Mremi is the head of the department, but he also teaches at the medical school and meets with medical students. The pathologists at KCMC perform autopsies, including the forensic autopsies that would normally be sent to a medical examiner or coroner’s office in the United States. Dr. Mremi was pulled away one day to do an autopsy and two other days to go to court to discuss autopsy findings. One of the days Dr. Mremi also performed an FNA, where he was not only preparing the slides, but procuring the specimen from the patient himself.

In the end I was able to go over one mastectomy case with each pathologist, but I had hoped to discuss my case study examples and talk to them about the differences in our grossing techniques in greater detail. When the pathologists were busy I would go over grossing techniques of the less complex specimens with the lab aides that perform grossing. Unfortunately the lab aides have responsibilities as accessioner, histotech, grossing aide, transcriptionist, etc. They do it all, so it was equally difficult to find time in their busy schedule. In addition to scheduling conflicts, there was also the issue of ventilation in the gross room. Because there is a window fan, but not proper ventilation, whoever is grossing could only be in the gross room for a limited amount of time before formalin exposure would be too much. I did bring a formalin 3m mask that was donated by a colleague of mine with some replacement cartridges that I hope they will implement into their routine.

In retrospect I wish I had known how difficult it would be to schedule my grossing time with both the pathologists and the lab aides. It takes a forceful and persistent personality to wrangle people into the gross room when they are bogged down with their other work. I wish I had known about this blog before my trip to Tanzania because this seems to have been previously stated by PAs. I would also recommend that the PA make sure to have all their transportation arrangements and initial appointments at the hospital set up in advance because you will essentially be dropped in a place with no Wi-Fi. I made sure to arrange all of this with the help of Alpa Pandya, Dr. Milner’s assistant, who was incredibly helpful. If you are able to exchange money in advance or schedule a trip to the bank with your airport driver this will be very helpful. The day I arrived was a Sunday so banks were closed. It was somewhat of a challenge to find a restaurant or local transportation that would take US dollars. I would recommend getting your visa before your trip because this may prove difficult to accomplish at the airport upon arrival. Be sure to get all the recommended vaccines and anti-malarial medicine if necessary in the area you are travelling. I was very surprised to see no mosquitos at all during my entire trip and find out that malaria is nearly eradicated in the Kilimanjaro region. I also had my clothing sprayed with an anti-bug spray that may have helped keep flies away from me. I would recommend people learn basic phrases (hello, thank you, please, etc.) in the language of the country they are visiting to be more respectful of the local people. Language apps such as Duolingo or Babel are a great help.

I recommend that if a PA is volunteering in a low resourced setting they find out exactly what would be most beneficial to the pathology department in that setting. Since my trip was more focused on breast mastectomy grossing I brought Lester, breast diagrams, templates, inking diagrams, breast protocols and procedures from my hospital, as well as multiple case examples. Some of which I laminated in advance so they could be used again and again in this setting. If I were to volunteer again I would try to set up a more concrete schedule in advance with exact times blocked out to discuss techniques, be in the gross room or give presentations. I am incredibly grateful I got to have this experience, I only wish I was able to make more of an impact. I hope that more PAs will continue to volunteer and that pathologists will participate in the telepathology volunteer roles to free up more time for the few pathologists in these low resource environments. Thank you again to ASCP, Dr. Milner and Alpa for this opportunity!

-Faith Fletcher is a Pathologists Assistant at Henry Ford Hospital in Detroit, Michigan.