Should Mumps be Bumped up the Public Health Agenda in India?

Introduction

The Universal Immunisation Programme (UIP) of India does not include the MMR vaccination. It currently vaccinates against measles, however not rubella or mumps [1]. By presenting data collected from the Kashmir Region of India, this paper aims to add to the body of literature supporting inclusion of the mumps vaccination in the UIP on the basis that it is a significant public health problem. We posit that it would be worthwhile ensuring routine MMR vaccination, thereby ensuring robust immunisation against measles and rubella also, tackling associated morbidity, mortality and economic sequelae. Mumps is a viral infection caused by a paramyxovirus. The virus spreads through direct contact with respiratory secretions, saliva or through fomites. It replicates in the upper respiratory tract and the average incubation period is 16 to 18 days. Mumps primarily affects the salivary glands, causing pain, tenderness and swelling in one or both parotid glands. Prodromal symptoms may precede parotitis by several days, consisting of low grade fever, myalgia, anorexia, malaise and headache. Parotitis typically lasts for at least 2 days. Spread is enhanced by longer and closer contact with an infected individual. Therefore it is advised that an infected individual should avoid contact with others from the time of diagnosis until 5 days post-onset of parotitis [2]. Vaccination is recognised as the best way to prevent mumps. The first vaccine against mumps was licensed in the United States in 1967- it is a live attenuated vaccine, given as a simple subcutaneous dose, usually in MMR which is a combination of Measles, Mumps and Rubella. According to the UK Centers for Disease Control, two doses of mumps vaccine are 88% effective at preventing the disease, and one dose is 78% effective. Vaccinated cases are less likely to present severe symptoms or complications than under- or unvaccinated cases [3]. The World Health Organisation and Indian Association of Paediatrics (IAP) recognise the vaccine as a highly effective way of preventing infection- the IAP includes it on its vaccination schedule [4].

Methods

The IDSP has been recording outbreaks of diseases including mumps. The epidemiological methods employed in this instance involved collecting the number of outbreaks and diagnosing cases based on clinical signs and symptoms. The WHO recommended clinical case definition is: ‘acute onset of unilateral or bilateral tender, self-limited swelling of the parotid or other salivary gland, lasting two or more days and without other apparent cause [12].’ Door to door visits occurred for patients in the affected villages and schools, examining for signs and symptoms. Additionally the living conditions and surroundings of the inhabitants were examined. The current rate of cases was compared to the background rate, and the outbreak described with respect to time place and person.

Results

From July 2017- September 2017 15 outbreaks were recorded in the Kashmir region by the IDSP, totalling 260 cases (Figure 2). The outbreaks were across 7 districts in 15 villages. The minimum number of cases in an outbreak was 7 and the maximum 50, averaging 17 patients per outbreak.

Figure 2: Kashmir Mumps Outbreak Data. The largest outbreak was in an educational institution, in keeping with findings from existing literature which indicates that group settings associated with educational institutions are at increased risk of outbreaks, be they small or large [16]. The majority of outbreaks were recorded in the Shopian District, totalling 5 outbreaks with 74 cases overall (Figure 3).

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Discussion

Mumps vaccination is a proven way of preventing infection with the virus, reducing severity of disease if contracted, and reducing transmission.Two doses of the vaccine are 88% effective at protecting against mumps and one dose is 78% effective [3]. Waning immunity is a recognised issue, however on balance with the benefits of vaccination, this paper argues that this is not reason enough to choose not to routinely vaccinate. During mumps outbreaks in highly vaccinated communities, the proportion of cases that occur amongst the vaccinated population may be high. However this should not result in defaulting to the belief that the vaccine is not effective. The effectiveness of the vaccine is assessed by comparing the rate of infection in the vaccinated cohort to the rate of infection in the non- vaccinated cohort. In outbreaks in highly vaccinated populations, the non-vaccinated cohort tends to have a greater infection rate than the vaccinated cohort [3]. Given the existence of the MMR vaccination which is used in many countries globally, we suggest that the benefits of ensuring vaccination against mumps in addition to rubella and measles would be a logical public health intervention that would have highly significant clinical and economic benefits. It would ensure vaccination against mumps in addition to greater immunization rates against measles and rubella.

Conclusion

The Indian Government proposes that mumps is not a significant enough public health problem to warrant routine immunisation, however the data presented from Kashmir suggests otherwise. Environmental methods alone are clearly not preventing outbreaks. Whilst the case study of Shopian District did not have any hospitalisations or deaths, there is still recognised morbidity associated with mumps infection and potential lifelong sequelae for infected individuals, which is a public health concern. Whilst this paper acknowledges that there are other communicable diseases with greater associated morbidity and mortality, it proposes that given the existence of the MMR vaccination, mumps is a virus that could easily be vaccinated against in combination with measles and rubella, joining over 100 countries worldwide who routinely vaccinate against the virus. This paper should be taken into account alongside other literature within the body of evidence that proposes mumps as a significant enough public health problem to warrant investment in prevention through vaccination.

Acknowledgements

State Surveillance Officer (SSO) Kashmir wishes to thank Director Health Services Kashmir, Mission Director NHM and Deputy Director Schemes for their continuous support and motivation. My thanks to Chief Medical officers (CMOs), Medical Superintendents and District Health officers (DHOs) of all the districts of Kashmir Division for their support. Thanks to staff at District Surveillance Units (DSUs) in all the districts. Special thanks are extended to Staff at State Surveillance Unit, namely Ms. Irfana Bhat (DEO), for compilation of data.

Author Statements

We declare that this manuscript is original, has not been published before and is not currently being considered for publication elsewhere. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for- profit sectors. We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. Ethical approval was not required for this paper as we present and analyze a data set obtained from other researchers that is properly anonymised. Informed consent was obtained at the time of original data collection. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.