Context: A mumps outbreak has been reported in the southern state of Kerala where, on a single day, 190 cases were recorded . As per data from the Kerala health department, there have been a total of 2,505 cases of this viral infection reported this month, and over two months this year, the number has reached 11,467 cases.

• Despite being a vaccine-preventable disease, mumps has never been a part of the Universal Immunisation Programme (UIP) because of the disease’s no-mortality profile and the perception that it has low public health significance.

• According to the World Health Organization (WHO), vaccination strategies targeting mumps control should be closely integrated with existing measles elimination and rubella control.

What is Mumps Disease?

• Mumps is caused by the paramyxovirus. 

• Mumps is an airborne viral disease primarily affecting children and adolescents. 

• Disease Symptoms: It manifests with symptoms like fever, headache, and painful swelling of the salivary glands, particularly the parotid glands on both sides of the face.

• It is also known as parotitis. 

• It transmits through close contact or airborne droplets from the respiratory system of an infected individual.

• Disease and its complications: In most cases, mumps is self-limiting, but it can lead to complications such as: Swelling of the brain; Hearing loss; Painful inflammation of the testis in adult males

• Age Group: While mumps mostly affects young children, it can infect teenagers and adults.

Is it a cause for concern? 

• Self-Limiting Disease: Mumps is described as a self-limiting disease, meaning it typically resolves on its own with rest and symptomatic management within about two weeks.

• Underreporting: Due to approximately half of infected children developing classical symptoms and around 30% remaining asymptomatic, many cases of mumps go unreported. This suggests that reported cases are likely a significant underestimation of the actual prevalence in the community.

• Public Health Perspective: Historically, measles has been prioritized in public health efforts due to its potential for severe morbidity and mortality, overshadowing the attention given to mumps.

• Emerging Concerns: Despite being less prioritized, recent reports indicate a surge in mumps cases, including complications such as encephalitis, epilepsy, aseptic meningitis, and acute pancreatitis, particularly at Kozhikode Medical College hospital.

• Impact on Reproductive Health: Mumps can affect the gonads (reproductive glands) in both males and females. In males, it poses the rare but significant risk of infertility or reduced sperm count in the long term.

Why is the mumps vaccine not part of the national immunization schedule?

• Lack of Mortality: Mumps typically does not result in fatalities, further contributing to the belief that it may not warrant inclusion in routine vaccination schedules.

• Underestimation of Public Health Significance: Despite arguments from organizations like the Indian Academy of Pediatrics (IAP) that mumps’ public health significance is underestimated, there has been insufficient evidence or data to prompt its inclusion in national immunization programs.

• Poor Documentation and Lack of Studies: Limited documentation of clinical cases, complications, and follow-up data, as well as a scarcity of published studies on mumps, have hindered efforts to fully understand its impact and advocate for its vaccine inclusion.

• Absence of Nationally Representative Data: The lack of nationally representative data on the incidence of mumps in India makes it challenging to assess its burden accurately and advocate for vaccine inclusion based on epidemiological evidence.

• Limited Information on Long-Term Morbidity: While mumps is known to have some impact on reproductive organs, there is very little information available on its actual long-term morbidity profile, further complicating decisions regarding vaccine inclusion.

How can the current outbreaks be controlled?

• Public Awareness Campaigns: Launch comprehensive public awareness campaigns to educate the community about mumps, its symptoms, transmission, and the importance of isolation. Emphasize the significance of vaccination and maintaining good hygiene practices.

• Improve Immunization Coverage: Strengthen efforts to improve general immunization coverage, especially targeting unimmunized children and adolescents. Ensure accessibility to vaccination services in all communities.

• Strict Isolation Measures: Enforce strict isolation measures for mumps patients for the full three-week duration to limit disease transmission. Provide clear guidelines to healthcare facilities and schools on managing mumps cases and preventing spread.

• School Closure: Consider temporary closure of schools during outbreaks to prevent further transmission, especially if a significant number of cases are reported among students. Use the summer break as an opportunity to break the chain of transmission.

• Enhanced Surveillance and Reporting: Implement robust surveillance systems to promptly detect and report mumps cases. Ensure healthcare providers are vigilant in diagnosing and reporting suspected cases to public health authorities for timely intervention.

• Contact Tracing and Monitoring: Conduct thorough contact tracing of individuals who have been in close contact with confirmed mumps cases. Monitor them for symptoms and enforce isolation measures if necessary to prevent secondary transmission.

• Healthcare Provider Training: Provide training to healthcare providers on mumps diagnosis, management, and reporting protocols. Ensure they are equipped to identify and manage cases effectively.

• Community Engagement: Engage with community leaders, schools, and parents to encourage cooperation with control measures. Encourage individuals to seek medical care promptly if they develop symptoms suggestive of mumps.

Road Ahead

• Assessment of Vaccine Effectiveness: Despite the lack of studies on the effectiveness of the mumps vaccine in India, global data suggests that two doses of the MMR vaccine can provide protection ranging from 70% to 95%, provided that coverage is high.

• Integration with Measles and Rubella Control: The World Health Organization (WHO) recommends integrating mumps vaccination strategies with existing efforts for measles elimination and rubella control. This ensures a comprehensive approach to vaccine-preventable diseases.

• Review of Vaccination Policies: Given the resurgence of mumps in Kerala, there is a need to reassess vaccination policies. Kerala’s initiative to replace the second dose of measles vaccination with MMR in 2014 aimed at protecting children from rubella. However, with the introduction of the MR vaccine in the Universal Immunization Programme (UIP) in 2017, Kerala switched to MR vaccine instead of MMR.

• Consideration of Regional Factors: Evaluate regional factors influencing vaccine effectiveness, disease burden, and immunization coverage. Tailor vaccination strategies accordingly to address the specific needs and challenges faced in Kerala.

• Consultation with Experts and Stakeholders: Engage with public health experts, immunization specialists, and stakeholders to review the evidence, assess the impact of different vaccination strategies, and determine the most effective approach moving forward.

• Monitoring and Surveillance: Strengthen monitoring and surveillance systems to track mumps cases, vaccine coverage, and vaccine effectiveness. This data will be crucial for evaluating the impact of vaccination strategies and making informed decisions.

• Policy Decision: Based on the evidence and expert recommendations, make a policy decision regarding the inclusion of MMR vaccine in the Universal Immunization Programme. Consider factors such as vaccine availability, cost-effectiveness, and logistics.

Conclusion

• Addressing the resurgence of mumps in Kerala necessitates a comprehensive approach, including vaccination integration, public awareness, strict isolation measures, and policy review guided by expert consultation and regional considerations.