|MILITARY MEDICINE - ORIGINAL ARTICLE
|Year : 2018 | Volume
| Issue : 2 | Page : 138-140
Clinico-epidemiological study of an adult mumps outbreak in a naval training establishment
Prabhat Chauhan1, Arun Gupta2, Amitabh Mohan3, Anmol Sharma4
1 Department of Medicine, INHS Asvini, Mumbai, Maharashtra, India
2 PMO, INS Kadamba, Karwar, Karnataka, India
3 Department of Surgery, INHS Asvini, Mumbai, Maharashtra, India
4 PMO, INS Gharial, Visakhapatnam, Andhra Pradesh, India
|Date of Submission||16-Mar-2018|
|Date of Acceptance||29-Oct-2018|
|Date of Web Publication||10-Jan-2019|
Surg Cdr Arun Gupta
INS Kadamba, Karwar - 581 308, Karnataka
Source of Support: None, Conflict of Interest: None
Introduction: Outbreaks of mumps are known in places of high population density because of close contact. Studies on mumps outbreak in adults have rarely been documented in India, although globally an epidemiological shift is noticed in the disease from children to young adults because of vaccination against the disease in childhood. Materials and Methods: This outbreak investigation was conducted at a sailor training center of the Indian Navy. All cases of fever with parotitis, orchitis, or features suggestive of mumps were included in the study. The clinical, epidemiological, and demographic data of all the positive cases were analyzed using a standardized questionnaire and review of medical records. Results: A total of 58 cases reported over 3 months. Forty-two cases were from a single division and 13 cases from the same dormitory as the index case. Parotitis (89.7%) was the most common presentations, and orchitis (13.8%) was the most common complication. The attack rate (AR) within the division was 15.46%, with overall AR of 2.32%. The incidence was 23.2 per 1000 per year. Case fatality rate of the disease was nil. Recommendations: Surveillance, early diagnosis, and prompt isolation remain the key to prevent the transmission of illness during an outbreak. Other preventive measures include health education of recruits and their instructors.
Keywords: Adult mumps, outbreak control, parotitis, recruits, subacute intestinal obstruction
|How to cite this article:|
Chauhan P, Gupta A, Mohan A, Sharma A. Clinico-epidemiological study of an adult mumps outbreak in a naval training establishment. J Mar Med Soc 2018;20:138-40
| Introduction|| |
Mumps is an acute, systemic, communicable viral infection characterized by unilateral or bilateral tender, self-limited swelling of the parotid, or other salivary gland(s). Agent responsible is a pleomorphic RNA virus, classified as genus rubulavirus of family paramyxovirus. The incubation period ranges from 14 to 18 days, with extremes of 7 and 23 days, patients are most contagious 1–2 days before the onset of symptoms. In India, sporadic cases and outbreak are reported throughout the year from all regions of the country. Ministry of health and family welfare, Government of India, has reported 45 outbreaks of mumps in 2016.
Outbreaks of the disease are known in places of high population density because of close contact, particularly in hostels, colleges, schools, military barracks, and in poor socioeconomic settings. Globally, an epidemiological shift is noticed in the disease from children to young adults because of vaccination against it in childhood. Studies on mumps outbreak in adults have rarely been documented in India. This study describes an outbreak of mumps in young males at a sailor training center of the Indian Navy.
| Materials and Methods|| |
This outbreak investigation was conducted between March 16 and June 16 (4 months). Recruits were divided into divisions for training purposes. Each division was a mix of different ethnic and social backgrounds who were clubbed in training activities such as physical training, meals, and breaks in between classes and swimming lessons. There was the daily interaction of the divisions. Divisions were accommodated into five dormitories during their stay at the center.
All cases of fever with parotitis, orchitis, or features suggestive of mumps were included in the study. Patients presenting with fever without symptoms suggestive of orchitis or parotitis were excluded from the study. All cases were male, as there was no female recruit at the center. All these cases were admitted to the isolation ward of a secondary care hospital for management.
A case of probable mumps, in this study, was as defined by Center for Disease Control and Prevention (CDC), Atlanta, i.e., a patient presenting with an acute parotitis or other salivary gland swelling lasting for at least 2 days, or orchitis unexplained by another more likely diagnosis, in a person with a positive test for serum anti-mumps immunoglobulin M (IgM) antibody; or a person with epidemiologic linkage to another probable or confirmed case or linkage to a group/community defined by public health authority during an outbreak of mumps.
Admitted patients were subjected to laboratory tests for confirmation of the diagnosis. Mumps was diagnosed by demonstration in acute phase sera of specific IgM antibodies.
The demographic, epidemiological, and clinical data of all the positive cases were analyzed using a standardized questionnaire and review of medical records.
| Results|| |
Index case reported with fever and parotitis on 8 March 2016. It was followed by other trainees of the same division presenting with similar complaints within 2 weeks (incubation period of mumps). The epidemic curve was prepared and is shown in [Figure 1]. It was suggestive of propagated epidemic with person-to-person transmission. The peak of the outbreak reached between 2nd and 4th week with subsequent secondary peaks, before it tailed off documenting the last case at the end of the 13th week. A total of 58 cases reported over 3 months.
Forty-two cases were from a single division and 13 cases from the same dormitory (within the division) as the index case. The average age of the patients was 19.33 ± 1.27 years. The average stay at the hospital was 9 ± 2.4 days. The attack rate (AR) of worst affected dormitory and the division showing maximum number of cases was 24.07% and 15.46%, respectively, with overall AR of 2.32%. The incidence was calculated as 23.2 per 1000 per year. Case fatality rate of the disease in the present outbreak was nil.
Parotitis was the most common presentations and was present in 52 (89.7%) cases at some point during the illness, 33 patients (56.9%) had unilateral, and 19 patients (32.8%) had bilateral involvement. Fever was noted in 34 cases (58.62%). It was intermittent with an average duration of 3.53 days (1–8 days). Fever was high grade in 27 (79.4%) cases. Odynophagia was documented in five cases (8.62%) [Figure 2].
Orchitis was the most common complication present in eight patients (13.8%), with six cases (10.34%) presenting it without a parotitis. These cases were diagnosed on the basis of IgM level for mumps antibodies. Pancreatitis, submandibular gland involvement, and subacute intestinal obstruction (SAIO) were seen in one patient each. Out of 58 patients, 49 did not have any complication.
Preventive measures were instituted simultaneously to contain the outbreak. Extensive health education regarding the mode of spread, prevention, and clinical presentation of mumps was given to recruits and the instructors. The recruits from the division with maximum number of cases were segregated from all other divisions. All instructors were instructed to actively look for cases with fever, facial pain, scrotal pain, or swelling and bring them to medical attention at the earliest. Furthermore, all cases with fever and/or orchitis and/or parotitis were admitted and hence effectively segregated. Swimming was stopped till control of the outbreak.
| Discussion|| |
In the past 15 years, mumps has shifted from being a disease of unvaccinated children into a disease of vaccinated young adults. Similar outbreaks as brought out by this study have been reported in other countries. A 2006 outbreak in the United States with 164 cases of mumps in undergraduates with AR of 0.9%, a 2009–2010 outbreak in Canada documented 790 cases, 57.6% being among 11–24 year age group with AR 4.82% and a 2012 outbreak in the United Kingdom 1557 cases documented, and 67.9% were from 18 to 24 age group reflect a similar demographic trend. Multiple outbreaks in immunized young military recruits have also been documented.
Similar to our study, orchitis was the most common complication, consistent with previous outbreaks studied in a similar population. One recruit developed mild acute pancreatitis due to mumps, it was also brought out by Taii A. in his case report published in journal of the pancreas (2008). No case of SAIO with mumps infection has been documented yet, but our study documents one case of SAIO among the cases. Although causing morbidity, mumps has rarely been fatal, as consistent with our study and other studies on the disease.
This shift in age distribution and the occurrence of mumps in vaccinated populations is probably the result of several coincident circumstances including situations promoting the spread of respiratory viruses among young adults (e.g., residence in college dormitories), waning of vaccine immunity with time, lack of endemically circulating wild-type virus to periodically boost vaccine-induced immune responses, and continuing global epidemics. Several studies have been done for measuring the immunity against mumps in young adults., A study from South India revealed low levels of protection of only 85% despite two doses of measles mumps rubella vaccination.
The Advisory Committee on Immunization Practices, CDC currently recommends the 3rd dose of mumps vaccination for persons who have received two doses of mumps vaccination and who are determined to be at high risk of acquiring infection during mumps outbreak. Several countries, including the US military, have adopted booster vaccination as a means of preventing mumps outbreaks especially in military recruits. A similar approach may be studied for prevention in the Indian Armed Forces, which at present does not recommend mumps vaccination to its recruits. Further studies need to be done in India both for civilians and the Armed Forces before homing onto the right strategy.
Surveillance, early diagnosis, and prompt isolation remain the key to prevent the transmission of the illness during an outbreak; thus, limiting the loss of vital training man-hours. Other preventive measures include health education of recruits and their instructors. Studies to determine the level of immunity and home onto optimal strategy such as booster dose of mumps vaccine to counter outbreaks need to be conducted in the Armed Forces.
Limitation of the study
The authors would like to admit that there existed no documentary evidence of previous vaccination and childhood history of mumps was not elicited owing to the poor reliability of such history, and this can be taken as a limitation of this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kasper DL. Harrisons' Principles of Internal Medicine. 19th
ed. New York: McGraw Hill Education Medical. 2015. p. 1129-30.
Urbano PR, Fujita DM, Romano CM. Reemergence of mumps in São Paulo, Brazil – The urgent need for booster shot campaign to prevent a serious infectious disease. Rev Soc Bras Med Trop 2017;50:535-8.
Bloom S, Wharton M. Mumps outbreak among young adults in UK. BMJ 2005;331:E363-4.
Cortese MM, Jordan HT, Curns AT, Quinlan PA, Ens KA, Denning PM, et al.
Mumps vaccine performance among university students during a mumps outbreak. Clin Infect Dis 2008;46:1172-80.
Deeks SL, Lim GH, Simpson MA, Gagné L, Gubbay J, Kristjanson E, et al.
An assessment of mumps vaccine effectiveness by dose during an outbreak in Canada. CMAJ 2011;183:1014-20.
Calvert N, Ashton JR, Garnett E. Mumps outbreak in private schools: Public health lessons for the post-wakefield era. Lancet 2013;381:1625-6.
Eick AA, Hu Z, Wang Z, Nevin RL. Incidence of mumps and immunity to measles, mumps and rubella among US military recruits, 2000-2004. Vaccine 2008;26:494-501.
Taii A, Sakagami J, Mitsufuji S, Kataoka K. Acute pancreatitis from mumps re-infection in adulthood. A case report. JOP 2008;9:322-6.
López-Perea N, Masa-Calles J, Torres de Mier MV, Fernández-García A, Echevarría JE, De Ory F, et al.
Shift within age-groups of mumps incidence, hospitalizations and severe complications in a highly vaccinated population. Spain, 1998-2014. Vaccine 2017;35:4339-45.
Kutty PK, Kruszon-Moran DM, Dayan GH, Alexander JP, Williams NJ, Garcia PE, et al.
Seroprevalence of antibody to mumps virus in the US population, 1999-2004. J Infect Dis 2010;202:667-74.
Malaiyan J, Duraipandian T, Warrier A, Menon T. Low rate of seropositivity (IgG) to mumps component in MMR vaccinees in Chennai, South India. Indian J Med Res 2014;139:949-51.
] [Full text]
Marin M, Marlow M, Moore KL, Patel M. Recommendation of the advisory committee on immunization practices for use of a third dose of mumps virus-containing vaccine in persons at increased risk for mumps during an outbreak. MMWR Morb Mortal Wkly Rep 2018;67:33-8.
[Figure 1], [Figure 2]