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Guidelines for the Shipment of
Dried Blood Spot Specimens

Centers for Disease Control and Prevention
Office of Health and Safety | Biosafety Branch
(Date Last Rev'd: March 9, 1995)

This information was published in Infant Screening, Vol. 16, No. 1, March 1993. It was written by:

Richard C. Knudsen1, William E. Slazyk2, Jonathan Y. Richmond1, and W. Harry Hannon2.

  1. Office of Health and Safety, Office of the Director; and
  2. Division of Environmental Health Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention (CDC), Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia, U.S.A.

Guidelines for the Shipment of Dried Blood Spot Specimens

Dried blood spot specimens are clinical specimens collected by carefully applying a few drops of blood, freshly drawn by finger stick with a lancet from adults, or by heel stick with a lancet from infants, onto specially manufactured absorbent specimen collection (filter) paper. The blood is allowed to thoroughly saturate the paper and is air dried for a minimum of 3 hours. Caked or clotted specimens are not acceptable and are therefore not shipped. The specimen collection technique and the specifications for specimen matrix and shipment have been published as a national standard by the National Committee for Clinical Laboratory Standards (1).

Specimen collection materials ("collection kits") for newborn screening may include a sturdy paper overlay that covers the absorbent filter paper containing the dried specimen. These are then enclosed and sealed in a highquality bond envelope. The paper overlay and the sealed bond envelope provide a double-layer barrier that protects casual handlers (i.e., shipping handlers and other nonlaboratory, non-technical personnel) from accidental exposure to the dried blood specimens and protects the specimens from exposure to the environment during shipping.

The dried blood spot specimens must NOT be packaged in airtight, leak-proof plastic bags (1) because the lack of air exchange in the inner environment of a sealed plastic bag causes heat buildup and moisture accumulation that can damage the dried blood spot test substances (2-5). In addition, various chemicals that can adversely affect the test substances in the dried blood spots could leach from these plastics and thus cause incorrect analytical test results. The inclusion of desiccant packs (1) will aid in prevention of moisture accumulation, but shipping conditions are uncontrolled and desiccant has a limited effectiveness.

Dried blood spot specimens are mailed to laboratories where the specimens are subject to various analytical procedures. One of the most important uses of this specimen collection technique is in screening for congenital and inherited metabolic disorders among the more than 4.2 million infants born annually in the United States. Efficient collection, shipment, and analysis of dried blood spot specimens on filter paper comprise the foundation of this important public health service. Other important applications include DNA (genetic) analyses, forensic studies, immunologic studies, and nutritional evaluations of infants, children, and adults.

REGULATIONS APPLICABLE TO PACKAGING AND SHIPPING

The U.S. Department of Health and Human Services regulation 42: Code of Federal Regulations (CFR) Part 72 - "Interstate Shipment of Etiologic Agents" (6) - specifically addresses the packaging and shipment of etiologic agents.

"Occupational Exposure to Bloodborne Pathogens: Final Rule" (7) generally addresses the shipping, transporting and labelling of containers of blood and body fluids. However, 42 CFR Part 72 specifically addresses, in detail, the shipment of biological products, clinical specimens, and etiologic agents. The 42 CFR 72 regulation is the reference source upon which other related guidelines are based.

Applicability of 42 CFR Part 72 to "Dried Blood Spot" Specimens

Paragraph 72.2 on page 48626 states that "No person may knowingly transport or cause to be transported in interstate traffic, directly or indirectly, any material including, but not limited to, diagnostic specimens and biological products which such person reasonably believes may contain an etiologic agent unless such material is packaged to withstand leakage of contents, shocks, pressure changes, and other conditions incident to ordinary handling in transportation."

If no evidence exists that a specific diagnostic specimen (including a dried blood spot), biological product, or other material contains an infectious agent, then there is no need to package the specimen or place a biohazard label on the specimen in compliance with 42 CFR Part 72. The packaging and shipping of these materials must comply with the requirements in 42 CFR Part 72 only if there is evidence that a diagnostic specimen or other material contains an etiologic agent. The package must bear the specified biohazard label to meet the requirements of this regulation.

Note that regulation 42 CFR Part 72 applies only to liquid or semisolid materials--including diagnostic specimens and biological products. Because blood spot specimens are absorbed into filter paper and dried, the packaging requirements of the blood spots as described in paragraph 72.3 on page 48626 do not apply, regardless of the source material. Therefore, all dried blood spot specimens contained on filter paper collection kits may be packaged for shipment in quality-bond paper envelopes, which meets the requirement of "packaged to withstand leakage of contents, shocks, pressure changes, and other conditions incident to ordinary handling in transportation."

However, if a dried blood spot specimen is reasonably believed to contain an etiologic agent (that is, if there is clear, underlying evidence that one or more etiologic agents are present), the packaging envelope should also bear a biohazard label to meet the requirements of this regulation. (This label may be supplemented with appropriate identifiers pertaining to newborn screening program specimens: e.g., "Dried biological materials [nonliquid] on absorbent paper--low biohazard risk.")

How the Proposed Amendment to 42 Part 72 could apply to Dried Blood Spot Specimens

Readers should be aware of the proposed amendment to 42 CFR Part 72, which was published in the Federal Register, March 2, 1990 (8). Final approval and release of this amendment is pending. If this amendment is approved, all human material would require a "clinical specimen" label whether or not such materials contain etiologic agents (e.g., "Dried biological materials [nonliquid] on absorbent paper").

The regulation would also require that the specimen be packaged in a primary container that "shall be packaged in an outer shipping container using shock resistant material to withstand conditions incident to ordinary handling in transit." Under this proposed amended regulation, dried blood spot specimens could still be packaged in the manner described in this paper, because the filter paper collection kit containing the dried blood spots is the primary container, and the high-quality bond envelope is the outer container.

Risk Evaluation

Dried blood spot specimens are routinely collected for numerous biochemical tests. The presence of an infectious agent in such specimens would be rare and incidental.

If a blood specimen that is absorbed and dried into the filter paper matrix did contain human immunodeficiency virus (HIV), the viral agent would be destroyed as the specimen was dried prior to shipping. When present, HIV is normally of low concentrations in circulating blood (2-3 logs per mL), and at least one log of infectivity titer is lost after several hours at ambient temperature in the dried state (9-11). Hepatitis B virus (HBV), on the other hand, may survive for an extended period of time in dried blood (12). However, when in the dried state, HBV is not readily transmissible. A person could not be exposed to HBV from a dried blood spot unless a suitable liquid, such as water, penetrated the sealed envelope, flowed inside to the absorbent paper, mixed with dried blood to suspend the virus, escaped in sufficient quantity to the external environment, and came in contact with a package handler. Opportunities for infection with HIV or HBV require direct entry into the blood stream through an open cut or penetration.

Thus for a package handler to be infected with HIV or HBV from a dried blood spot in a sealed envelope, a rare combination of circumstances would have to occur: the blood specimen would have to contain viable HIV or HBV; the virus would have to be present in blood in sufficient quantity to cause an infection; the virus would have to survive for extended periods of time in the dried blood spot; liquid would have to penetrate the sealed envelope; the virus would have to escape to the outside environment; and the virus would have to directly enter the bloodstream of a package handler by penetration or through an open wound. In other words, a shipping handler or other casual package handler could be exposed to infectious agents that may occasionally be present in dried blood spot specimens only under the most unusual circumstances -- circumstances that extend beyond those "conditions incident to ordinary handling in transportation."

Summary

Dried blood spot specimens can be shipped or transported by mail or other carrier with no reasonable expectations of occupational exposure to blood or other potentially infectious material. "Universal precautions" are to be followed in collecting and preparing these specimens for shipment. Standard filter paper collection kits should be enclosed and sealed in high quality paper mailers -- ideally, extra-strong, tear-proof, air-permeable, and waterresistant envelopes. These steps provide reasonable safety from occupational exposure and maintain optimal specimen integrity.

REFERENCES

  1. National Committee for Clinical Laboratory Standards. NCCLS Approved Standard LA4-A2. Blood collection on filter paper for neonatal screening programs. Villanova, PA:National Committee for Laboratory Standards, June 1992.
  2. Hannon WH, Lewis DS, Jones WK, Powell MK. A quality assurance program for HIV seropositivity screening of dried-blood spot specimens. Infect Control Hosp Epidemiol 1989;10:8-13.
  3. Levy HL, Simmons JR, MacCready RA. Stability of amino acids and galactose in the newborn screening filter paper blood specimen. J Pediatr 1985;107:757-60.
  4. Davis G, Poholek R. Stability of dried blood spots on paper as used in screening neonates for hypothyroidism. Clin Chem 1979;25:24-25.
  5. Mizuta H, Miyai K, Ichihara K, et al. Radioimmunoassay of "free thyroxin" in dried blood spots on filter paper: preliminary observations on the effective differentiation of subjects with congenital hypothyroidism from those with subnormal thyroxin-binding globulin and normal subjects. Clin Chem 1982:28:507-8.
  6. Federal Register. 42 CFR part 72. Interstate shipment of etiologic agents. 1980;45:48626-7.
  7. Federal Register. 29 CFR part 1910.1030. Occupational exposure to bloodborne pathogens: final rule. 1991;56:64175-82.
  8. Federal Register. 42 CFR part 72. Interstate shipment of etiologic agents: notice of proposed rulemaking. 1990;55:7678-82.
  9. Resnick L, Veren K, Salahuddin SZ, Tondreau S, Markham PD. Stability and inactivation of HTLV-III/LAV under clinical and laboratory environments. JAMA 1986;255:1887-91.
  10. McDougal JS, Martin LS, Cort SP, et al. Thermal inactivation of the acquired immunodeficiency syndrome virus, human T lymphotropic virusIII/lymphadenopathy-associated-virus, with special reference to antihemophilic factor. J Clin Invest 1985;76:875-7.
  11. Evengard B, von Sydow M, Ehrnst A, et al. Filter paper sampling of blood infected with HIV: effect of heat on antibody activity and viral infectivity. Br Med J 1988;297:1178.
  12. Bond WW, Favero MS, Petersen NJ, et al. Survival of hepatitis B virus after drying and storage for one week. Lancet II 1981:550-1.

Biosafety Branch | Office of Health and Safety
Centers for Disease Control and Prevention
404 639-3235

Office of Health and Safety, Centers for Disease Control and Prevention,
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Last Modified: 5/20/97
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