Hand-Foot-and-Mouth Disease in Calicut

Transcription

1 Hand-Foot-and-Mouth Disease in Calicut C.K. Sasidharan, P. Sugathan, Ramesh AgarwaP, Shashi Khare 1, Shiv LaP and C.K. Jayaram Paniker 2 Baby Memorial Hospital, Calicut, Kerala, ~National Institute of Communicable Disbases, Delhi, 2Microbiology Centre, Calicut, Kerala, India Abstract. Objective: Hand-Foot-and-Mouth Disease (HFMD) is a mild exanthematous illness seen worldwide, affecting mainly children under ten years of age. The causative agents were initially Coxsackie virus type A 16 and related serotypes. The situation changed drastically about thirty years ago with the advent of a new aetiological agent, Enterovirus type 71 ( EV 71 ), which has caused very large outbreaks with severe complications and many deaths. Methods: The authors report an outbreak of papulovesicular lesions on the skin and oral mucosa compatible with the diagnosis of HFMD in children in and around Calicut in October Clinical and laboratory study in collaboration with the National Institute of Communicable Diseases, Delhi. Eighty one children with the syndrome were examined and followed up from October 2003 to February 2004, when the outbreak subsided. Result: The outbreak was mild and all children recovered within 1 to 2 weeks. Conclusion: Acute and convalescent paired serum samples collected from 19 patients were examined at the NICD for IgM antibody against EV 71 by microneutralisation test in cell culture. All the paired samples tested showed significant rise in titre of antibodies, confirming the diagnosis of EV 71 infection in each of them. [Indian J Pediatr 2005; 72 (1) : 17-21] babymhospital org Key words: Hand-Foot-and-Mouth Disease; Enterovirus 71 Hand-Foot-and-Mouth Disease (HFMD) was identified as a clinical entity in 1957 in Toronto, Canada during an outbreak of a mild febrile disease characterized by papulovesicular lesions on the skin and in the mouth, but the name HFMD was first used only in 1960 during a similar outbreak in Birmingham, England. I The causative agents were identified as enteroviruses - principally Coxsackie virus A 16, and also Cox. A 4-7, 9, 10; B 1-3 and 5 serotypes. Infection usually occurs by the fecal-oral route, leading to viremia and invasion of the skin and mucosa. The incubation period is 3-7 days, followed in some cases by a brief prodrome of mild fever and malaise. Clinical illness presents usually with enanthems. Thin-walled vesicles on the hard palate, tongue, lips and buccal mucosa, which ulcerate and may coalesce, make feeding difficult due to pain. These lesions undergo spontaneous healing in 5-7 days. Rarely, the oral lesions may be the only manifestation ('herpangina'), but usually skin lesions also are present. Clusters of papulovesicular lesions occur on the skin, commonly on the hands, fingers, trunk, buttocks and feet. The palms and soles are often affected. The exanthems are usually painless and fade in1-2 weeks without scarring. 2 A change in the severity of the illness took place in the 1970s, when a new pathogen, Enterovirus-71 (EV 71) appeared giving rise to large epidemics with much Correspondence and Reprint requests : Dr. C.K. Sasidharan, Anugraha, East Hill Road, Calicut , Kerala. Fax : fatality among children. Japan, Taiwan, Singapore, Malaysia, Indonesia and other countries in the Asia- Pacific region reported extensive epidemics involving thousands of patients. In Taiwan, a continuing surveillance program was initiated which disclosed that EV-71 was causing succeeding epidemics of varying virulence and intensity. The mortality and complication rates were much more in the later epidemics than in those preceding. Because of this transformation of a mild self limited condition to a killer disease, increasing attention is now being paid to the study of HFMD. India has apparently not had any experience of epidemic HFMD caused by EV-71 infection. Because of the continuing activity of this virus in our neighborhood for about three decades, it is likely that India also might experience an invasion by the virus. Few medical personnel in the country are familiar with HFMD and most are not in a position to make a clinical diagnosis of the cohdition. Therefore during an outbreak of an illness, clinically suggestive of HFMD, we studied its clinical, epidemiological and virological features. MATERIALS AND METHODS The patients studied were children brought with papulovesicular exanthems to the outpatient clinic run by one of us (C.K.Sasidharan). The patients came from Calicut city, its suburbs, as well as from areas within an approximate radius of 30 km. The study began in October 2003 when this was first noticed as a new condition and Indian Journal of Pediatrics, Volume 72~anuary,

2 C.K. Sasidharan et al was continued till February 2004 when the outbreak subsided. Month-wise distribution of the 81 children with the syndrome was as follows: 2003 October - 15; November - 49; December - 09; 2004 January - 05; February The history and clinical examination findings of the patients were recorded. Routine laboratory tests of their blood, urine and stool were done. Routine bacteriological cultures were done with throat swabs and stools of the patients. Histopathological study was done with biopsy from a few lesions. Photographs of the lesions were taken in some cases for record. Blood samples of patients were collected on first contact and two weeks later, sera separated and stored in the cold till they were examined together at the National Institute of Communicable Diseases, Delhi. Microneutralisation test was done by standard procedure using Hep-2 cell and EV-71 strain (obtained from the Enterovirus Research Centre, Mumbai). Serial twofold dilutions (1:2 to 1:128) of heat inactivated serum samples in maintenance medium were prepared in duplicate and 100 ml of each dilution added to wells of micro cell TABLE 1. Presenting Symptoms & Signs of HFMD (n=81) Symptoms & Signs No. Fever 58 Running Nose 62 Irritability 43 Salivation 63 Papulovesicular lesions 69 Oral ulcers 75 Palms 58 Hands 58 Elbows 76 Chest 57 Buttocks 32 Thigh 48 Knee 58 Feet 74 Soles 81 culture plate, followed by 100 TCID50 of EV-71 in 0.1 ml and incubated at 37~ for two hours. The micro cell culture plate was then seeded with 1000 Hep-2 cells/well and incubated at 37~ in 5% CO2 for 7 days. Antibody titre was taken as the reciprocal of the highest serum dilution showing no cytopathic effect. The samples were tested in duplicate and all relevant controls included. 3 RESULTS Of 81 patients seen with clinical HFMD, 53 were males and 28 females. The ages ranged from 7 months to 8 years (< 3 yr=65; 3 - <6 = 14; >6 = 02). All had, as presenting signs, papulovesicular lesions on the skin over the extremities, trunk and enanthems over the lips, oral mucosa, tongue and hard palate (Table 1). The presenting complaint was the skin or mucosal lesion. Oral lesions often showed inflammation and ulceration resulting in pain and difficulty in feeding. The exanthems were usually present in clusters of 3 to 10 vesicles. Ulceration of skin lesions was not commonly seen. Routine clinical examination showed only mild fever in a few of the patients; the rest did not show evidence of any systemic illness. Routine blood examination showed results within normal range, except for moderate neutrophil leucocytosis in 59 children. Bacteriological examination of swabs from vesicle fluid and throat did not yield any bacterial pathogens. Biopsy of the vesicle lesion in a few patients showed koilocytic changes consistent with those seen in viral vesicles. Scrapings from vesicle base showed only neutrophils. Serological tests for EV-71 were performed on 19 patients. Their serum samples were collected on first presentation and again days later. Acute and convalescent serum pairs were transported on ice to Delhi for IgM antibody assay. Specific microneutralization tests done in cell cultures showed that all 19 samples of sera TABLE 2. Seroconversion Ratio of Patients, with Their Name & Age No. Name\ Age Antibody No. Name Age Antibody (initials) (yr) Rise in titre (initials) (yr) Rise in titre 1 M 2 4 fold 11 S 9 8 fold 2 A fold 12 D 1 16 fold 3 S fold 13 M 1 8 fold 4 A 8 16 fold 14 A fold 5 S 1 4 fold 15 A 5 6 fold 6 A fold 16 R 1 4 fold 7 S 2 8 fold 17 M 2 4 fold 8 M fold 18 E 2 8 fold 9 A fold 19 R 4 4 fold 10 R fold* * Acute and convalescent serum antibody titres were 1:64 and 1:128 respectively. The acute serum was collected only six days after the onset by which time the titer has risen, and this explains the two fold increase only. But this is considered positive because of the high titre. 18 Indian Journal of Pediatrics, Volume 72~January, 2005

3 Hand-Foot-and-Mouth Disease in Calicut Fig. 1 & 2. Papular eruptions in the gum & tongue with inflamed oral mucosa Fig. 3. Hands showing multiple papulo--vesicular lesions Fig. 4. Elbow with papulo-vesicular lesionsfig.5. Forearm with multiple papulo-vesicular eruptions Indian Journal of Pediatrics, Volume 72~January,

4 C.K. Sasidharan et al Fig. 6. Buttock showing popular eruptions Fig. 7. Knee with papulo-vesicular lesions Fig. 8. Soles with papulo-vesicular lesions Fig.9,10 & 11. Microphotograph of an early lesion showing subcomeal bullae filled with plenty of polymorphonuclear infiltrate and epidermis showing spongiosis epidermotropism. Suprapapillary thinning and enormously dilated papillary capillaries upper dermis showing edema and venodilatation. 20 Indian Journal of Pediatrics, Volume 72--January, 2005

5 Hand-Foot-and-Mouth Disease in Calicut had significant rise in titres of IgM antibody against EV- 71 (Table 2). All patients appeared cured within days. No specific treatment was given, though analgesics and antipyretics were used in some cases. The lesions healed by crusting which left no permanent scars. No sequelae were noticed on observation for one month after recovery. DISCUSSION In recent decades, many new diseases have appeared and old diseases reappeared in new forms. These emerging and re-emerging infections have posed severe problems in public health in various countries. HFMD caused by EV-71 appears to be one such, which has undergone a transformation from a minor self limited illness to a major epidemic, causing many deaths and leaving serious neurological and other sequelae. This has been particularly so in Asian countries, from Japan and Taiwan in the north to Malaysia, Indonesia and Singapore in the south. Taiwan has reported results of a continuing surveillance program against HFMD from Thousands of'patients have been investigated. Their observation that the disease which was milder in the beginning, acquired more virulence in subsequent attacks is alarmingd Like other non-polio enteroviruses, EV-71 also can cause a number of different clinical conditions, ranging from asymptomatic infection, to aseptic meningitis, encephalitis, flaccid paralysis, myocarditis, pulmonary hemorrhage, diarrhea and HFMD. Three genotypes of EV-71, A,B and C have been recognized. The relations, if any between the genotypes and virulence have not been established, though in Taiwan, isolates from successive epidemics have been shown to have different genotypes predominant. 5 There has been only one recorded isolation of EV-71 from India so far. In 2003, Deshpande and colleagues from the Enterovirus Research Centre, Mttmbai isolated a strain of EV-71 from the stool of a 5-year-old-child from Haryana with acute flaccid paralysis (AFP) following oral polio vaccine. This was a lone case as no other EV-71 strain was found among non-polio enteroviruses from 101 AFP cases from the same area. This was genetically different from the A,B and C genotypes of EV-71 and has been proposed as a new genotype D. 6 Viral isolation attempts have not been made during the present study. Some stool samples from patients and contacts have been stored for further tests. However, the finding that all 19 paired serum samples from patients tested showed fourfold or greater rise in antibody against EV-71 in specific microneutralisation test is conclusive proof that the virus was the causative agent. In the case of enteroviruses, specific serology is a more reliable evidence than virus isolation from stools, because the latter may be due to carrier state which is very common, but rise of antibody proves current infection. This report deals only with 81 patients over a period of four months, but that number represents only patients presenting before a single pediatric consultant. There are very many pediatricians and hospitals in this area who could have seen similar patients, without considering the diagnosis of HFMD. Many other patients would have consulted general p'ractitioners, dermatologists, physicians or other categories of doctors. No attempts were made to assess to assess the numbers involved, but enquiries from doctors revealed that they also had seen patients with similar lesions during the period. Early detection of an outbreak is important in initiating control measures. There is no specific vaccine or antiviral agent against EV-71. The use of oral polio vaccine and of acyclovir has been reported, but no beneficial results have been published. Prevention therefore depends largely on public health promotion. In India now, when children as well as adults report with vesicular lesions, they are often labeled as herpes, varicella or some other eruptive illness. As most of them are self limited and heal soon, there is no pressure for further investigation. HFMD is not usually considered in differential diagnosis because it is not a familiar condition now. This report may be useful in providing awareness of this potentially dangerous threat. There is now evidence for the presence of EV-71 in India, by way of its isolation from a suspected Gullain-Barre patient in the North, and this serologically proved outbreak in the South. The virus has been seeded into a vast population of presumably nonimmune subjects, in an environment favoring fecaloral transmission, a combination that bodes ill for the future. Acknowledgement Authors express their sincere gratitude to Dr.K.G.Alexander, Chief Physician and Managing Director, Baby Memorial Hospital, Calicut for providing the necessary laboratory facilities and permitting to use the hospital records for this study. REFERENCES 1. Tindall J, Miller G. Hand Foot and Mouth Disease. Cutis 1972; 9 : Nelson Text Book of Pediatrics. 17 ~ edn, Hand-Foot-And- Mouth Disease, Lenette EH, Schmidt NJ. Cell culture techniques. In Diagnostic Procedures for Viral, Rickettsial and Chlamydial Infections. American Public Health Association, Washington DC-20005, 5 ~ edn. 1975; 4. Ho M, Chen ER, Hsu Kt I, Twu SJ, Chen KW, Tsai SF et al. New Eng ] Medicine 1999; 341 : Wang VR, Tuan YC, Tsai HP, Yan JJ, Liu CC, Su IJ. Change of Major Genotype of Entero Virus 71 in Out breaks of Hand Foot and Mouth Disease in Taiwan between J Clin Microbio12002; 40(1): Deshpande JM, Nadkarni SS, Francis PP. Enterovirus 71 isolated from a case of acute flaccid paralysis in India represents a new genotype. Current Science 2003; 84; Indian Journal of Pediatrics, Volume 72---January,