Correspondence: Immunisation; Burning feet; Blood test fasting

It is correct that certain vaccinations are available, fully funded, for adults who have never had a course of vaccinations, and have not been exposed to the condition being vaccinated against. There are three vaccines in this category that are available to anyone, at any age: Td (tetanus/diphtheria), MMR (measles, mumps and rubella) and IPV (polio). The funding includes the Immunisation Benefit Subsidy to cover the cost of delivery. The funding for the age 45 and 65 year Td booster is different in that, unlike other vaccines, the dose is funded, but the cost of administration (Immunisation Benefit Subsidy) is not. The reason for this is largely historical. So in summary, if the Td is being given as a primary course, not a booster dose, then the Immunisation Benefit Subsidy can be claimed.

Some other vaccinations are funded for adults in certain scenarios, such as people pre- or post splenectomy (HiB, Meningococcal A, C, Y and W135 and pneumococcal polysaccharide vaccines), people who are household or sexual contacts of Hepatitis B carriers and Tdap vaccine for women who are pregnant. In addition, influenza vaccination is funded for people aged over 65 years, women who are pregnant and those with a chronic condition outlined within the New Zealand Immunisation Handbook (although funding rules are subject to change).

Other vaccines that may be useful to adults and should be considered, but are not funded, include varicella for those without a history of chicken pox and pneumococcal vaccines for those with chronic chest conditions.

Women have until their 20th birthday to begin the HPV immunisation programme. This means that the first dose must be delivered prior to their twentieth birthday, but subsequent doses may be given beyond this age.

Recommended vaccinations for staff working in primary care

In Table 1 in the article “Recommended vaccinations for staff working in primary care” (BPJ 49; Dec, 2012), some of the table notations were incorrectly labelled. This inadvertently occurred when reproducing the table. The notations have now been corrected in the online version of this article, available from: www.bpac.org.nz

The original table is also available from: www.immune.org.nz

In the “burning feet” sidebar of the article you refer to, ESR was suggested as an investigation that may be considered, along with serum protein electrophoresis and serum free light chains or Bence Jones protein in urine to rule out the possibility of multiple myeloma in a patient with burning feet (and other reasons to suspect multiple myeloma as a cause). We agree that ESR alone is not useful for diagnosing multiple myeloma as it lacks specificity - while ESR is usually elevated in people with multiple myeloma when CRP is normal, there are many other potential causes of a very high ESR. This approach to investigating possible multiple myeloma (i.e. ESR + other tests) is recommended in the British guideline for multiple myeloma,¹ and in other literature.²

However, after consultation with several laboratories and haematologists it appears that the growing consensus in New Zealand is that measurement of ESR is no longer recommended when investigating possible multiple myeloma. A practical approach, if myeloma is suspected, is to first request serum protein electrophoresis. If an increase in immunoglobulins is found, or the test is normal but clinical suspicion remains, the need for further testing (e.g. serum free light chains or Bence Jones protein) should be discussed with a haematologist or other relevant specialist.

National laboratory testing guidelines are currently in development, and it is likely that serum free light chains will be one of several tests that are recommended for restricted use. We will provide an update on these guidelines when they become available.

References

1. Bird J, Owen R, D’sa S, Et al. Guidelines for the diagnosis and management of multiple myeloma 2011. Brit J Haematol. 2011;154(1):32–75.
2. Watson J, Round A, Hamilton W. Raised inflammatory markers. BMJ. 2012;344:e454.

Recommendations for the length of a fasting period for glucose and lipid tests vary between laboratories. The accepted minimum fasting time is eight hours,1 but twelve hours is preferable.

Water may be drunk during the fasting period, but tea and coffee (even without milk) should not be consumed. Caffeine can temporarily produce a small, but detectable, transient increase in serum glucose levels (approximately 10%).² The reason for the increase is not well understood, as overall insulin sensitivity is not affected by caffeine.² It is likely that the effect comes from either increased bioavailability of glucose or from a relative effect on insulin secretion. The effect of caffeine on lipid levels is less significant and is unlikely to alter fasting blood test results (unless milk or cream is also added).³ However, to avoid confusion, it may be best to advise patients not to drink tea or coffee during a fasting period for any fasting blood test.

HbA_1c is recommended in preference to fasting glucose for investigating diabetes in most people, as, among other reasons, the requirements of a fasting glucose test are a significant burden to many patients.

There is increasing debate as to whether a non-fasting lipid test is adequate for a cardiovascular risk assessment. Patient compliance is likely to be higher if a lipid test can be performed “now”, rather than asking the patient to fast and present at a laboratory in the morning. However, current cardiovascular risk assessment guidelines are based on fasting test results.

We hope to follow this debate and update this issue in the future.

For further information on the use of fasting glucose see: “When to use a fasting glucose to diagnose type II diabetes”, Best Tests December (Dec, 2012).

References

1. Editor: Kyle C. A handbook for the interpretation of laboratory tests. 4th ed. Diagnostic Medlab; 2008.
2. Krebs JD, Parry-Strong A, Weatherall M, Et al. A cross-over study of the acute effects of espresso coffee on glucose tolerance and insulin sensitivity in people with type 2 diabetes mellitus. Metabolism 2012;61(9):1231–7.
3. Zargar A, Auttapibarn C, Hee Hong S, Et al. The effect of acute café latte ingestion on fasting serum lipid levels in healthy individuals. J Clin Lipidol 2012;In press, corrected proof.