Predictive power of Koplik’s spots for the diagnosis of measles

  • Dominik Zenner Centre for Infection, HPA, London UK/ London School of Hygiene and Tropical Medicine, UK
  • Luis Nacul PHG Foundation, Cambridge, UK/ London School of Hygiene and Tropical Medicine, UK
Keywords: (MeSH), measles, Koplik’s spots, epidemiology, predictive value

Abstract

Introduction: Measles is a major cause of mortality globally. In many countries, management of measles is based on clinical suspicion, but the predictive value of clinical diagnosis depends on knowledge and population prevalence of measles. In the pre-vaccine era with high measles incidence, Koplik's spots (KS) were said to be "pathognomonic". This study prospectively evaluated test properties and diagnostic odds ratios (OR) of KS.

Methodology: Data including KS status were prospectively collected for a six-month period on all suspected measles cases reported to the North-West London Health Protection Unit. Saliva test kits were sent to all cases and KS test properties were analysed against measles confirmation by PCR or IgM testing (gold standard).

Results: The positive predictive value (PPV) of clinically suspecting measles was 50%. Using KS as diagnostic tool improved the PPV to 80% and the presence of KS was associated with confirmed measles in the multi-variable analysis (OR 7.2, 95% Confidence Interval 2.1-24.9, p=0.001).

Conclusion: We found that Koplik's spots were highly predictive of confirmed measles and could be a good clinical tool to enable prompt measles management and control measures, as action often needs to be taken in the absence of laboratory confirmation. We suggest that current clinical case definitions might benefit from the inclusion of KS.

Author Biography

Dominik Zenner, Centre for Infection, HPA, London UK/ London School of Hygiene and Tropical Medicine, UK
Dr Dominik Zenner MD MA MSc MFPH T(GP), is Public Health Registrar at the Centre for Infection, Health Protection Agency, Medical Advisor to the British Paediatric Surveillance Unit (BPSU) and Honorary Research Fellow at the London School of Hygiene and Tropical Medicine (LSHTM). He is also a practicing General Practitioner and currently working on the General Practice Research Database (MRC grant). He has a special interest in HIV and STIs, published internationally and regularly reviews articles in this area for JIDC. As a GP and public health practitioner he also takes an interest in the evaluation of clinical signs and symptoms.
Published
2011-11-30
How to Cite
1.
Zenner D, Nacul L (2011) Predictive power of Koplik’s spots for the diagnosis of measles. J Infect Dev Ctries 6:271-275. doi: 10.3855/jidc.1756
Section
Original Articles