key: cord-0010392-p4b08jtf authors: Ijaz, M.K.; Alharbi, S.; Uduman, S.A.; Cheema, Y.; Sheek-Hussen, M.M.; Alkhair, A.R.A.; Shalabi, A.G.; Ijaz, S.S.; Bin-Othman, S.A.; Sattar, S.A.; Liddle, L.F. title: Seasonality and prevalence of rotavirus in Al-Ain, United Arab Emirates date: 2002-11-05 journal: Clin Diagn Virol DOI: 10.1016/0928-0197(94)90002-7 sha: 4b6785dc1c8e0a8ec289190790f7a5c7f1892914 doc_id: 10392 cord_uid: p4b08jtf Background: Rotaviruses are the single most important causative agent of acute neonatal enteritis in most avian and mammalian species including humans. Rotaviruses infections have also been shown to be associated with the elderly, immunocompromised individuals and more recently with epidemic diarrheal illness in adults. Objectives: To study the incidence and the effect of seasonality on the prevalence of rotaviruses in Al-Ain, United Arab Emirates. Study design: A total of 650 stool samples submitted to the laboratories of two University Teaching Hospitals (Al-Ain and Tawam) and a private hospital (Oasis) were examined for the presence of rotaviruses from January 1990–December, 1992, using a commercially available latex agglutination assay. The meteorological data (temperature, relative humidity and rainfall) recorded during the sampling period was analyzed statistically to examine the effect of seasonality on the prevalence of rotavirus cases in Al-Ain, United Arab Emirates. Results: Rotavirus was detected in 21.4% of the samples examined. The predominant number of positive cases (35%) were in the 7–12 months age group. It was interesting to find rotavirus-positive cases in as low an age group as <3 months (3.6%) and as high as 10 years (8.04%). There was no significant difference on infection rates between male and female groups in the study. However, there was a significant difference between the national (38.18%) and non-national children (61.28%). The higher rate of the latter may be due to import of infections. There appeared to be a seasonal pattern of rotavirus occurrence in the cases studied, with a marked increase in the number of positive cases during the months when the relative humidity was low (25–45%) and there was no rainfall. Conclusions: Rotavirus was detected in all age groups with a predominance in 7–12 month age groups, and a higher incidence in non-nationals. There was a marked increase in the number of positive cases during the months when the relative humidity was low (25–45%) and there was no rainfall. These findings are discussed in relation to the epidemiology and prophylaxis of rotavirus infections. To study the incidence and the effect of seasonality on the prewllence ot" rotaviruses in A1-Ain, United Arab Emirates. Teaching Hospitals (A1-Ain and Tawam) and a private hospital (Oasis) were examined for the presence of rotaviruses from January 1990-December, 1992, using a commercially available latex agglutination assay. The meteorological data (temperature, relative humidity and rainfall) recorded during the sampling period was analyzed statistically to examine the effect of seasonality on the prevalence of rotavirus cases in AI-Ain, United Arab Emirates. Results: Rotavirus was detected in 21.4% of the samples examined. The predominant number of positive cases (35%) were in the 7-12 months age group. It was interesting to find rotavirus-positive cases in as low an age group as <3 months (3.6%) and as high as 10 years (8.04%). There was no significant difference on infection rates between male and female groups in the study. However, there was a significant difference between the national (38.18%) *Corresponding author. Fax: (+971) 3-5113(15. 0928-0197,,94,$7.00 :'-', 1994 Elsevier Science B.V. All rights reserved SSDI 0928-0197( 94 )000 I 3-K and liOn-national children (61.28')<,t. The higher rate o1" the latter may be duc to import of infections. There appeared Io bc a seasonal pattern of rolavirus ocCtllTence ill the cases studied, with a marked increase in the number of positix, e cases during the inonths whe11 the relative humidity was low (25 45<){,) and there was no rainfall. Conclusions: Rotavirus \~as detecled in gill age groups with a predominance in 7 12 month age groups, and a higher incidence in ilon-natiol3als. There was a lllarkcd increase in the number o1" positive cases during ttle months \~hen the relative humidity was low (25 45'!;,I ;.lild there was no rainl'all. These findings ;_ire discussed in relation to lhc epidemiolog) ~.ll-ld prophylaxis of rotaxirus infecticms. t:ollowing the discovery of rotavirus in the feces ot" calves sufl'eril3g from diarrhea ( Mebus et al.. 1969) , and in biopsy specimens of an infant's intestinal tissue ( Bishop et al., 1973 ) , it has been reported that rotaviruses are ubiquitous animal and human pathogens that cause significant diarrheal diseases in most lnammalian and avian species (Flewett et al., 1974 : Flewett and Babiuk, 1984 : Estes and Cohen, 1989 : Kapikian et al., 1974 : Kapikian and Chanock, 1990 : Middleton et al.. 1974 . More recently, rotaviruses have been shown to be involved in causing extra-intestinal infections in immunodeficient children (Gilger el al., 1992t . They have been associated with enteritis particularly in young ammals (under one month of age) and in infants (six months to two years). Epidemics of rotavirus among adults ( l h'dy. 1987, tlung. 1988 ) and the elderly havc also been described (Kapikian and Chanock, 1990) . It has been estimated that oxer 500 × 10" cases el'diarrhea occur ammally in humans, resulting either directly or indirectly in approximately 10 × 10" deaths, of which approximately 1 x 10'> deaths have been attributed to rotaviruses ( DeZoysa and Feachem, 1985; and Ratalia, 19{47) . Despite their significant involvement in pcdiatric diarrhea, the role played by, thesc viruses remained undetermined in human populations in the United Arab Emirates ((IAE). The present prelect, therefore, was designed to detine the role of rotaxiruses in pediatric hospitalized diarrheal cases. This information has shed some light on the role of thcsc viruses in acute xiral enteritis in the local population. In addition it defined the eft'cot of seasonaliiy on the prewilence of rotavirus in this part (AI-Ain)of tile t!AE. Stool samples were collccted from tile pediatric wards of hospitalized children sult'ering fl'om diarrhea in tile A1-Ain Medical District. The AI-Ain Medical has three main hospitals serving a population of approximately two hundred thousand. AI-Ain Hospital (serving mainly expatriates but UAE Nationals arc also served here) and Tawam ttospital (serving mainh: UAE nationals but a limited number o1" expatriates, mainly hospital employees or cases referred from A1-Ain hospital are also served here) are the large teaching hospitals with 420 beds and 245 beds respectively. The third hospital, Oasis Hospital is a private hospital which serves both populations and has 45 beds. Stools or rectal swabs were collected in sterile containers and sent immediately to the laboratories of the respective hospitals for rotavirus analysis. These samples underwent routine bacteriological or parasitological examination. The samples were examined for the presence of rotavirus using commercially available latex agglutination assay (Rotazyme, Abbott Laboratories, IL USA or Rotalex, Orion Diagnostica, Espoo, Finland). The statistical analysis was performed using different computer software. Z-Test was applied to determine the significant difference between the two populations. The data was processed on DOS 5.0 editor for statistical analysis on Statistical Package for Social Sciences (SPSS) software. Harvard Graphics software was used for the graphical presentation of both clinical and meteorological data. Between January, 1990 to December, 1992, a total of 650 stool samples were analyzed for the presence of rotavirus. Rotavirus was detected in a total of 139 (21.4'7,,) of the samples submitted to the three hospitals. It was interesting to note that none of the samples which were positive for rotavirus were positive for any other infectious agent. Rotavirus was detected in all age groups under study ( Fig. 1 ) A under three months as well as in the group of over 10 years of age. The rotaviruspositive cases were analyzed statistically to determine if there was any significant difference between different sex groups (rotavirus was detected in 43% of male and 57% of female stool specimens) and no significant difference between the two groups was observed. The rotavirus-positive cases were also analyzed to determine if there is any difference between the local (nationals) [38.18%] and expatriate [61.82%] populations and a significant difference (P < 0.01) between the two populations was observed. To determine the effect of seasonality on the prevalence of rotavirus in diarrheal cases, the meteorological data o13 temperature, relative humidity (RH) and rainfall (RF) during the sampling period (January, 1990 December, 1992) was obtained from the Division of Meteorology. Department of Agriculture, A1-Ain, United Arab Emirates. Rotavirus was detected throughout the year with its predominance durmg the months with low RH and no rainfall, and during the months with relatively low temperature ( Fig. 2 1 Rotaviruses remain an important pathogen-inducing diarrhea in infants and young children in both developed and developing countries of the world. In AI-Ain the population is mixed, i.e., locals and expatriates representing the Middle East, South East Asia, the Subcontinent, North America, Australia and Europe. Therefore, the presence of rotavirus in the A1-Ain population was not a surprise. Rotavirus was detected in all age groups under study and predominately in the 7 12 months age group. It was interesting to note that rotavirus was also recovered in the group of less than 3 months of age. This agreed with the age incidence observed in Nigerian (Oyejide and Fagbami, 1988) , Native American Indians in the United States (Santosham et al., 1985) and Mexican children (Velazquez et al., 1993) . The increasing incidence of rotavirus in children after the age of 6 months coincided with the age weaning usually begins and with the age at which maternally derived antibodies start to decline. Rotavirus have been reported in adults and the elderly (Bourgeois et al., 1993; Hrdy, 1987; Pryor et al., 1987) . In the present study we also observed rotavirus in older children (> 10 years). The importance of rotavirus in this age group and in adults needs further investigation. The role of seasonality in rotavirus dissemination is poorly understood. In our study rotavirus was detected throughout the year, with its predominance during the months with low RH, no rainfall and with relatively low temperature. Cook et al. (1990) have analyzed the data from 34 global studies to investigate the seasonal patterns of rotavirus gastroenteritis and considered their implications on the transmission of the virus. According to their report the global pattern of rotavirus is quite distinct, with its predominance in the cooler months only in the Americas. 111 most of the world the virus is present throughout the year, which suggests that a low level of transmission occurs all the year round and that humans are a suitable reservoir. The results of our study taken together with the findings of Cook et al. (1990) suggest that temperature alone does not account directly for this broad seasonal pattern and that other environmental factors like RH probably play a significant role in the dissemination of rotaviruses (Ansari et al., 1991; ljaz et al., 1984 : 1985a ,b, 1987 Sattar and ljaz, 1987) . Al-Ain is located 150 km east of the capital city of Abu-Dhabi and is 400 meters above sea level. It is a traditional oasis with a climate ranging between a relatively cool, dry winter and a hot, dry summer. The percentage incidence of rotavirus infection during all the years of study revealed that it peaks in the months of March, April, May, October, November and December (Fig. 2) . A comparison of meteorological data with rotavirus percentages throughout the year revealed a significant relationship of the monthly temperature, RH, and RE with rotavirus frequency. More rotavirus-positive cases occurred when there was low temperature, low RH and no RF. Fewer cases occurred in the months with high temperature, RH and rainfall. In conclusion, our observations point towards an endemicity of rotavirus infection in the area studied. The infection was more frequent during the cooler, less humid months and in the periods of low RF. Further studies are indicated to extend this to the other regions of the country, particularly those situated on the coast where RH is much higher throughout the year than in A1-Ain. The virus appears to be responsible lk)r inducing enteritis in the age groups studied (<3 months to > 10 years). Rotavirus has been recovered in diarrheal cases among adults and the elderly {Bourgeois et al., 1993; Hrdy, 1987: Hung, 1988: Kapikian and Chanock, 199{) ). Further studies need to be done to look into the possible involvement of rotavirus infections in similar age groups here in Al-Ain and other parts of the UAE, with particular reference to the involvement of different rotavirus serotypes. The information obtained from such studies should be helpful in designing a rotavirus vaccine to control these infections. Survival and vehicular spread of human rotaviruses, Possible relation to scasonality of outbrcaks Virus particles in epithelial cells of duodenal mucosa from children v, ith acute non-bacterial gastroenteritis. 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In Fields Calf diarrhea (scours): reproduced with a virus from a field outbreak Orbivirus acute gastroenteritis of inl;ancy. Lancet i I988) An epidemiological study of rotavirus diarrhea in a cohort o1" Nigerian infants. Incidence of diarrhea in the first two years of life Acute diarrhea in adults, a prospective study Worldwide opportunities in genetically engineered vaccines Epidemiology of rotavirus diarrhea in prospectively monitored American Indian population Transmission of viral infectious through airborne route Cohort study of rotavirus serotype patterns in symptomatic and asymptomatic infections in Mexican children We are grateful to the laboratory staff of A1-Ain, Oasis and Tawam Hospitals for analysis of stool samples initially. The technical assistance of Mr. Z. Babarindae is highly appreciated in carrying out part of this work. We also acknowledge the support of The Faculty of Medicine and Health Sciences, United Arab Emirates University and the Ministry of Health, United Arab Emirates.