Hand, Foot and Mouth Disease: A Single Centre Retrospective Study of 403 New Cases and Brief Review of Relevant Indian Literature to Understand Clinical, Epidemiological, and Virological Attributes of a Long-Lasting Indian Epidemic

Abstract

Background: There have been sporadic and periodic large-scale epidemics of hand, foot, and mouth disease (HFMD) with cases at risk for significant morbidity and mortality particularly in Southeast Asia since 1997 and in India since early 2003.

Method: We retrospectively studied 403 cases recorded from 2009 to 2019 and reviewed relevant Indian literature published between 2004 and 2019 to understand clinical, epidemiological, and virological attributes of this long-lasting Indian epidemic.

Result: There were 96.8% children and adolescents (M:F 1.6:1) aged 2 months to 18 years and 84% were aged <5 years. Adult family contacts comprised 3.2%. Only 12 sporadic cases occurred during 2009-2011 followed by increased number from 2012 to 2015 peaking with 30.8% cases in 2013 and declining slowly until the year 2019 with small resurge in 2018. The major peaks occurred during summers with small peaks in autumns. Literature review showed 3332 cases presenting between 2004 and 2019 across Indian states with similar epidemiological trends whereas serotyping identified Coxsackievirus A16 (CV A16) in 83%, Coxsackievirus A6 (CV A6) in 17%, Enterovirus 71 in 4.1%, and multiple strains in 11.7% samples, respectively.

Conclusion: The overall features of this long-lasting HFMD epidemic; affecting children aged <5 years more often than adults, none or minimum neurological or pulmonary complications in few patients, peaks occurring during summer and autumn months, and identity of the pathogenic virus coincide with global trends. However, the continuous spread of the disease across the country appears in sync with pre-epidemic periods of China and Taiwan. It calls for a continuous surveillance and making HFMD a notifiable disease in India.

Keywords: Coxsackievirus A16; HFMD; India; Southeast Asia; coxsackievirus A6; epidemic; human enterovirus 71; onychomadesis; viral infection.

Figure 1

Geographic distribution of hand, foot and mouth disease cases in India (The 403 cases from this study are also shown here together with those reported from Himachal Pradesh in the literature). Note: News papers also reported small outbreaks of HFMD cases between the year 2012 and 2014 from - Delhi, Goa, Srinagar, Arunachal, Meghalaya, Nagaland, Manipur, Tripura, Mizoram, Daman and Diu, Lakshadweep, Punjab, Chandigarh, Haryana, Uttar Pradesh, Bihar, Madhya Pradesh, Chhattisgarh, and Jharkhand

Figure 2

Year wise distribution of HFMD cases from our study centre. The initial number of cases between 2009 and 2011 had increased to peak in 2013. Small peaks occurred in subsequent years

Figure 3

Month wise distribution of HFMD cases from our study centre. The major peaks occurred in 2013-14 during summer months (March to June). Small peaks occurred during autumn months (September to November)

Figure 4

Small multiple round/oval macules and pearly-white vesicles with a red areola over (a) palms and (b) dorsa of feet in a 5-year-old child. Small yellowish-white aphthae-like lesions with surrounding erythematous areola are involving labial mucosa in a 3-year-old child (c). Similar lesions were present over buccal mucosa and anterior palate. Characteristic erythematous macules and pearly-white vesicular lesions are seen over (d) buttocks, and (e) knees in a 3-year-old child

Figure 5

Characteristic skin lesions of hand, foot and mouth disease in mother of an affected child involving palms (a) and feet (b) only. Oral lesions were not perceptible in her

Figure 6

Nail changes of onychomadesis of index fingernail, leukonychia and mild dystrophy of other nails in a 5-yr-old child seen 2 months after HFMD

Figure 7

Year wise distribution of cases reported from India between 2003 and 2019. A rising trend in number of cases was seen from 2003 onwards that peaked between 2012 and 2015 before declining in subsequent years. Sporadic cases are still reported