To The Editors:
We write in response to the recent letter by Leggiadro, 1 which stressed the importance of diagnosing complement deficiencies (CD) in patients with meningococcal disease (MCD).
This is in contrast to our service where following a review of 297 MCD patients, we do not routinely screen for CD (incidence, 0.3%). 2
In the US MCD is rare (1.1/100 000; <1 year, 10.7/100 000; 1 to 4 years, 4.7/100 000 3) compared with England, Wales and Northern Ireland (9.1/100,000; <1 year, 162/100 000; 1 to 4 years, 50.9/100 000 4, 5). Incidences vary considerably in other countries. 6–8
Epidemiologic data, first documented by Densen, 9 showed that as the incidence of MCD increases the incidence of CD decreases. The prevalence of CD in patients with MCD varies from <1% to 50%. 9 It is postulated that in epidemic areas protective antibodies rates are low and therefore complement sufficient patients are more likely to be infected than those with CD. The converse is true in regions where is MCD rarer, i.e. the US.
In regions where MCD is relatively common, we suggest CD should be investigated in the following situations: where MCD has been attributed to an unusual serogroup (i.e . not B or C); in patients who have had two separate proven episodes of MCD; and in meningococcal serogroup C vaccine failures. The last category, difficult to define, comprises patients with MCD who have had significant and or recurrent bacterial infection previously. 2
When considering whether to screen MCD patients for CD the local incidences of MCD and if available of CD (in MCD patients) should guide judgments. In regions where universal screening is not adopted, we suggest that patients fulfilling any of the above criteria should be screened.
Scott J. Hackett, M.B., Ch.B., M.R.C.P. (UK)
Terence J. Flood, M.A., M.R.C.P.I.
1. Leggiadro RJ. Systemic meningococcal infection and complement deficiency. Pediatr Infect Dis J 2003; 22: 760–1.
2. Hoare S, El-Shazali O, Clark JE, Fay A, Cant AJ. Investigation for complement deficiency following meningococcal disease. Arch Dis Child 2002; 86: 215–7.
3. Centers for Disease Control and Prevention. Active Core Surveillance (ABCs) Report Emerging Infections Program Network Neisseria meningitidis
, 1999. Available at http://www.cdc.govs/abcs
4. PHLS. Enhanced surveillance of meningococcal disease: cases identified by age in England, Wales and Northern Ireland 1/1/99–31/12/99. Available at http://www.phls.org.uk/topics_az/meningo/meni-tots.htm
5. National Statistics. Population: age and sex, 1971 onwards: Population Trends 112. Available at http://www.statistics.gov.uk/STATBASE/ssdataset.asp?vlnk
=6902, September 2003.
6. Peltola H, Jonsdottir K, Lystad A, Sievers CJ, Kallings I. Meningococcal disease in Scandinavia. Br Med J 1982; 284: 1618–21.
7. de Mateo Ontanon S. Meningococcal disease in Spain, 1990–1997: change in its epidemiological pattern. Rev Esp Salud Publica 2000; 74: 387–96.
8. Piscopo T, Mallia-Azzopordi C, Grech V, Muscat M, Attard-Montalto S, Mallia C. Epidemiology and prognostic factors in meningococcal disease in a small island population: Malta 1994–1998. Eur J Epidemiol 2000; 16: 1051–6.
9. Densen P. Complement deficiencies
and meningococcal disease. Clin Exp Immunol 1991; 86: 57–62.