Hand-foot-mouth disease: outbreak in Shimla

Applicability of duplex real time and lateral flow strip reverse-transcription recombinase aided amplification assays for the detection of Enterovirus 71 and Coxsackievirus A16

BACKGROUND

Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the two main etiological agents of Hand, Foot and Mouth Disease (HFMD). Simple and rapid detection of EV71 and CA16 is critical in resource-limited settings.

METHODS

Duplex real time reverse-transcription recombinase aided amplification (RT-RAA) assays incorporating competitive internal amplification controls (IAC) and visible RT-RAA assays combined with lateral flow strip (LFS) for detection of EV71 and CA16 were developed respectively. Duplex real time RT-RAA assays were performed at 42 °C within 30 min using a portable real-time fluorescence detector, while LFS RT-RAA assays were performed at 42 °C within 30 min in an incubator. Recombinant plasmids containing conserved VP1 genes were used to analyze the sensitivities of these two methods. A total of 445 clinical specimens from patients who were suspected of being infected with HFMD were used to evaluate the performance of the assays.

RESULTS

The limit of detection (LoD) of the duplex real time RT-RAA for EV71 and CA16 was 47 copies and 38 copies per reaction, respectively. The LoD of the LFS RT-RAA for EV71 and CA16 were both 91 copies per reaction. There was no cross reactivity with other enteroviruses. Compared to reverse transcription-quantitative PCR (RT-qPCR), the clinical diagnostic sensitivities of the duplex real time RT-RAA assay were 92.3% for EV71 and 99.0% for CA16, and the clinical diagnostic specificities were 99.7 and 100%, respectively. The clinical diagnostic sensitivities of the LFS RT-RAA assay were 90.1% for EV71 and 94.9% for CA16, and the clinical diagnostic specificities were 99.7 and 100%, respectively.

CONCLUSIONS

The developed duplex real time RT-RAA and LFS RT-RAA assays for detection of EV71 and CA16 are potentially suitable in primary clinical settings.

Risk factors for neurogenic pulmonary edema in patients with severe hand, foot, and mouth disease: A meta-analysis

OBJECTIVE

To investigate the risk factors for neurogenic pulmonary edema (NPE) in patients with severe hand, foot, and mouth disease (HFMD) and to provide evidence for the prevention and treatment of NPE.

METHODS

Several databases were searched (from inception to 2017) to identify case-control studies on risk factors for NPE among patients with severe HFMD. Data were analyzed via meta-analysis. The combined odds ratio (OR) and 95% confidence interval (CI) were calculated using fixed-effects and random-effects models, and a sensitivity analysis and evaluation of publication bias was also performed.

RESULTS

A total of 14 studies involving 557 cases (severe HFMD with NPE) and 1450 controls (severe HFMD) were included. Results for the categorical variables were as follows: hyperglycemia (OR 10.25, 95% CI 4.82-21.76), tachycardia (OR 6.21, 95% CI 3.02-12.75), hypertension (OR 3.79, 95% CI 2.90-4.95), respiratory rhythm abnormality (OR 7.86, 95% CI 2.46-25.12), drowsiness (OR 8.11, 95% CI 4.26-15.44), vomiting (OR 8.96, 95% CI 3.83-20.96), limb tremors (OR 8.96, 95% CI 3.83-20.96), atypical rash (OR 4.27, 95% CI 2.83-6.45). No significant publication bias was found for the different factors.

CONCLUSIONS

Drowsiness ranks first among risk factors for NPE in children with severe HFMD, followed by vomiting, tachycardia, hypertension, breathing rhythm changes, limb tremors, atypical rash, and hyperglycemia.

Delayed Cutaneous Findings of Hand, Foot, and Mouth Disease

OBJECTIVE

To describe various delayed cutaneous findings associated with hand, foot, and mouth disease (HFMD).

METHODS

Patients presenting with clinical features of HFMD were followed-up prospectively for a period of 3 months for the occurrence of delayed cutaneous manifestations.

RESULTS

Out of 68 patients on regular follow-up, 23 (33.8 %) showed different types of skin and nail changes following HFMD. Nineteen showed features of onychomadesis, 9 developed nail discoloration, and Beaus line was noted in 5 patients. Cutaneous desquamation was seen in 7 patients. Spontaneous re-growth of nails occurred in all cases within 12 weeks follow-up. Skin desquamation subsided by 2-4 weeks.

CONCLUSION

Delayed cutaneous findings following HFMD are common.

The Epidemiology of Hand, Foot and Mouth Disease in Asia: A Systematic Review and Analysis

CONTEXT

Hand, foot and mouth disease (HFMD) is a widespread pediatric disease caused primarily by human enterovirus 71 (EV-A71) and Coxsackievirus A16 (CV-A16).

OBJECTIVE

This study reports a systematic review of the epidemiology of HFMD in Asia.

DATA SOURCES

PubMed, Web of Science and Google Scholar were searched up to December 2014.

STUDY SELECTION

Two reviewers independently assessed studies for epidemiologic and serologic information about prevalence and incidence of HFMD against predetermined inclusion/exclusion criteria.

DATA EXTRACTION

Two reviewers extracted answers for 8 specific research questions on HFMD epidemiology. The results are checked by 3 others.

RESULTS

HFMD is found to be seasonal in temperate Asia with a summer peak and in subtropical Asia with spring and fall peaks, but not in tropical Asia; evidence of a climatic role was identified for temperate Japan. Risk factors for HFMD include hygiene, age, gender and social contacts, but most studies were underpowered to adjust rigorously for confounding variables. Both community-level and school-level transmission have been implicated, but their relative importance for HFMD is inconclusive. Epidemiologic indices are poorly understood: No supporting quantitative evidence was found for the incubation period of EV-A71; the symptomatic rate of EV-A71/Coxsackievirus A16 infection was from 10% to 71% in 4 studies; while the basic reproduction number was between 1.1 and 5.5 in 3 studies. The uncertainty in these estimates inhibits their use for further analysis.

LIMITATIONS

Diversity of study designs complicates attempts to identify features of HFMD epidemiology.

CONCLUSIONS

Knowledge on HFMD remains insufficient to guide interventions such as the incorporation of an EV-A71 vaccine in pediatric vaccination schedules. Research is urgently needed to fill these gaps.

Vesiculobullous Disorders in Children

OBJECTIVE

To study the frequency and clinical pattern of vesiculobullous disorders in children.

METHODS

A retrospective chart review of all children diagnosed with vesiculobullous disorders over a period of 36 mo from January 2011 through December 2013 was performed. All children 18 y and below were included in the study.

RESULTS

A total of 213 children presenting with vesiculobullous lesions were examined during the study period. Vesiculobullous disorders constituted 3.6 % of the total 5889 dermatoses seen during this period. The most common vesiculobullous disorder in children was infections (129, 60.6 %), followed by genodermatoses (35, 16.4 %), inflammatory disorders (33, 15.5 %), drug reaction (7, 3.3 %) and trauma (5, 2.3 %). Autoimmune and metabolic disorders constituted 1.4 % (three children) and 0.5 % (one child) respectively.

CONCLUSIONS

This study highlights the varied spectrum of vesiculobullous disorders seen in the pediatric population. Cutaneous infections and inherited disorders were the most common disorders observed in the present study.

Comparative epidemiology and virology of fatal and nonfatal cases of hand, foot and mouth disease in mainland China from 2008 to 2014

This study aimed to analyze the epidemiology and virology of fatal and nonfatal hand, foot, and mouth disease (HFMD) cases in Mainland China. A total of 10,714,237 survivors and 3046 deaths were reported from 2008 to 2014 June, with a case fatality rate of 0.03%. The morbidity of the survivors increased from 37.6/100,000 in 2008 to 139.6/100,000 in 2013 and peaked in 2012 at 166.8/100,000. However, the mortality varied around 0.03-0.04/100,000 across the time. Most of the survivors were distributed in the southern and eastern China, predominantly in the Guangxi and Hainan Province, whereas deaths were dominant in southern (Guangxi) and southwestern (Guizhou) China. The two groups showed similar seasonal fluctuations from 2008 to 2014, peaking in spring and early summer. Of the total cases, 93.97% were children less than 5 years of age, with those ≤ 2 years old accounting for 60.08% versus 84.02% in the survivor and death groups, respectively. Boys were at higher risk of infection than girls in both groups. Five years of virological surveillance showed that 43.73%, 22.04%, and 34.22% of HFMD cases were due to EV71, CoxA16 and other enteroviruses, respectively. EV71 was encountered in most deaths, with no substantial effect of age, gender, month, and year on incidence. Subgenotype C4a was the prevalent EV71 strain in Mainland China, with no significant difference in the VP1 gene related to virulence between the two groups. In conclusion, based on the largest population study, fatal and nonfatal HFMD cases, mainly caused by C4a of EV71, are circulating in Mainland China with a low-cause fatality rate.