Background
Measles morbillivirus (MV) is one of the most contagious human pathogens known 1.
MV infection occurs worldwide 2, sporadically or through outbreaks, such as the current outbreak in South Africa. Since late 2022, MVoutbreaks have been declared in 5 provinces, namely, Limpopo, Mpumalanga, North West , Gauteng, and Free State. Since the start of the outbreak, a total of approximately 400 cases have been confirmed 3. Due to the highly infectious nature of the virus, coupled with low immunization coverage, the risk of a broader, national outbreak is high. Clinicians should be on high alert for potential MV cases, which will assist with early detection and general outbreak response measures.
Clinical Features and Stages of Infection
MV infection typically presents with fever and a maculopapular rash. Figure 1 expands on the stages of infection. Atypical MV presentations are possible, specifically in patients with partial immunity and those with immune-compromise. The latter group of patients may present without the typical measles rash.
Complications of MV infection
MV infection carries a high risk of developing one or more complication (~ 30% of cases), and can lead to complications involving
almost all organs and systems 6.
Possible complications include (list not exhaustive):
• Diarrhoea (most common)
• Pneumonia
• Encephalitis (Acute demyelinating encephalomyelitis [ADEM], sub-acute sclerosing pan-encephalitis [SSPE], measles inclusion
body encephalitis [MIBE] )
• Immunosuppression and secondary bacterial infections
• Xerophthalmia and blindness
• Otitis media
Treatment and Prevention
There is no specific antiviral agent to treat measles. Treatment is supportive and aimed at alleviating symptoms and preventing complications. Vitamin A should be given to all children with measles to prevent eye damage.
For severe complications such as pneumonia, there has been some anecdotal success with the non-specific antiviral agent, ribavirin 7,8.
For prevention of MV infection, there are safe and effective vaccines (monovalent and the polyvalent MMR vaccine). MV vaccines are typically given as part of the expanded programme on immunization (EPI), in a t wo-dose schedule.
MV vaccines can be used for post-exposure prophylaxis (PEP) if given within 72 hours of the exposure. In cases where vaccination is contraindicated (eg < 6 months of age, pregnancy, severe immune compromise etc) immune globulin may be used for PEP if given within 6 days of the exposure.
Laboratory diagnosis
At Pathcare we offer serological (IgM and IgG) as well as molecular (PCR) testing. See Table 1 for more details. A positive IgM or positive PCR typically confirms an acute MV infection.
Conclusion
During outbreaks of measles it is important to have a high index of suspicion, especially where a patient presents with fever and rash.
Laboratory testing for measles is important, especially at the beginning of an outbreak, or outside of an outbreak setting.
Please note that measles is a notifiable condition in South Africa. Please report all cases to the NICD via the NMC app or by manually
completing the necessary forms, available on the NICD website. For measles testing, a case investigation form needs to be completed in
conjunction with the standard Pathcare request form. Notification forms available at: https://www.nicd.ac.za/diseases-a-z-index/measles/
For further clinical queries and testing advice, contact one of our clinical virologists.
References
1. Strebel PM, Orenstein, WA. Measles. N Engl J Med 2019; 381:349-357. DOI: 10.1056/NEJMcp1905181
2. Gans H, Maldonado YA. Measles: Clinical manifestations, diagnosis, treatment, and prevention. Uptodate. https://www.uptodate.com/contents/
measles-clinical-manifestations-diagnosis-treatment-and-prevention
3. National Institute for Communicable Diseases. South African Measles Outbreak 2023 (18 January 2023). https://www.nicd.ac.za/south-africanmeasles-
outbreak-2023-18-january/
4. Gans H, Maldonado YA. Measles: Epidemiology and transmission. Uptodate. https://www.uptodate.com/contents/measles-epidemiology-andtransmission?
topicRef=3021&source=see_link
5. Department of Health, National Expanded Program on Immunization, Pretoria, South Africa. Republic of South Africa, Expanded Programme on
Immunisation (EPI), National Coverage Survey Report 2020. https://www.health.gov.za/wp-content/uploads/2022/03/National-EPI-Coverage-
Survey_Final-full-report-Dec-2020.pdf
6. Misin A et al. Measles: An Overview of a Re-Emerging Disease in Children and Immunocompromised Patients. Microorganisms 2020, 8, 276;
doi:10.3390/microorganisms8020276
7. Pal G. Effects of ribavirin on measles. J Indian Med Assoc. 2011;109(9):666.
8. Forni AL et al. Severe measles pneumonitis in adults: evaluation of clinical characteristics and therapy with intravenous ribavirin. Clin Infect Dis .
1994;19(3):454.
Prepared by Dr Howard Newman, Clinical Virologist, Pathcare, 021 596 3400.
Credit – The Pathcare News