Clinical Features for Mild Hand, Foot and Mouth Disease in China

Abstract

Background: Mild hand, foot and mouth disease (HFMD) is at a critical stage owing to its ease of communicability and a higher risk of developing severe complications and death. Clinical diagnosis of mild HFMD was made by the presenting symptoms and signs (symptoms in brief) alone. We aim to evaluate the frequencies of symptoms in a retrospective case series study.

Methods: We collected epidemiological, demographic, clinical, and laboratory data from outpatient and inpatient settings on the clinical data warehouse system. We principally described the frequencies of symptoms of mild HFMD. Correlations between symptoms with laboratory-confirmed cases were then analyzed.

Results: The clinical data warehouse system included 3649 probable cases, between 2010 and 2012, of which 956 (26.20%) were laboratory confirmed. The peak incidence was identified in children 2 years of age. A total of 370 of the 956 laboratory confirmed cases (38.70%) were associated with enterovirus 71 (EV71). Logistic regression analysis adjusted for geographical variables, age, sex, month of onset, and time from onset to diagnosis showed that the clinical features constipation (P<0.0001; adjusted OR, 95%CI (2.99, 2.28-3.91)), and blisters (P<0.0001; adjusted OR, 95%CI (2.16, 1.82-2.56)) were positively correlated with the confirmed cases.

Conclusions: This is the largest case series study, including all the guideline-mentioned symptoms of mild HFMD. Our findings suggest that blisters and constipation should be considered as potential warning signs while front-line clinicians manage surges of children diagnosed with mild HFMD during a pandemic.

Fig 1. Geographical distribution of probable cases and laboratory-confirmed cases of mild HFMD by Chinese province.

Fig 2. Age distribution of mild HFMD from the Clinical Data Warehouse System and other reports.

C#, probable data; L#, laboratory confirmed data.

Fig 3. The arc diagram of symptoms and signs of patients with mild HFMD.

The symptoms and signs were included in the guideline issued by China (black nodes, Guide Group) or previous study (grey nodes, Potential Warnings Group).

Fig 4. Most Frequent On Symptoms and Signs Sorted by Relative Risk.

The first panel displays the percent of symptoms and signs, with different symbols for each group. The second panel displays the relative risk of a symptom on the laboratory-confirmed cases relative to the probable cases, with 95% confidence intervals for a 2 × 2 table.