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PubMed1996

The effect of combined rotavirus and Escherichia coli infections in rabbits.

In rabbits, experimentally induced rotavirus infection results in soft feces only; thus it is unlikely that it is the sole cause of the severe, often fatal diarrhea of weanling rabbits with which it is associated. To determine whether rotavirus acts synergistically with another pathogen, New Zealand White rabbits (10 to 38 weeks old) were inoculated with rotavirus (L:ALA:84) and/or Escherichia coli 015:H-(RDEC-1) via orogastric tube. A single dose of high-titer (10(6) fluorescent focus-forming units) rotavirus was used, whereas E. coli was administered in various doses (10(2) to 10(9) CFU) to determine the titer of E. coli that induced only mild diarrhea but, when combined with rotavirus, resulted in diarrheal disease. Doses of E. coli > 10(6) CFU resulted in infection in almost all rabbits 10 to 16 weeks old, as detected by fecal shedding, regardless of whether rotavirus was inoculated simultaneously. However, inoculation of > 10(6) CFU of E. coli, in conjunction with rotavirus, resulted in increased morbidity and mortality due to diarrheal disease compared with E. coli alone. Inoculation of rabbits 28 to 38 weeks old with similar doses of rotavirus and E. coli caused infection but failed to induce diarrhea, indicating that older rabbits were more resistant to the pathogenic effects of these two agents. A synergistic effect between rotavirus and E. coli occurred, causing more severe diarrheal disease in weanling rabbits than that resulting from either pathogen alone.

Aging↗
PubMedDate not supplied

[Rotaviruses in human and veterinary medicine].

Rotaviruses are the commonest cause of diarrhea and are responsible for more than 25% of all deaths from diarrhea worldwide. Children become infected early in life and most infections in infants older than 3 months are symptomatic. These viruses account for 18 million cases of moderate or severe disease and 900,000 deaths each year. The incidence of rotaviral disease is similar in developed and developing countries but the number of deaths is higher in developing countries. Infections occur throughout the year in developing countries but are seasonal in developed countries, occurring mainly between October and March. The mean age at first infection is 6 to 9 months in developing countries and 9 to 15 months in developed countries. The greater severity of infections in developing countries is associated with malnutrition, lower hygiene standards and the lactose malabsorption and deficiencies of zinc and vitamin A that accompany diarrhea. Many mixed infections also increase the severity of the rotavirus infection. The clinical symptoms of the disease in hospitalized patients are diarrhea, vomiting and dehydration. There is more vomiting than with bacterial infections. The severity of the clinical symptoms depends on the virulence of different strains. The disease is more severe and persistent in patients with reduced immunity. Age also has an effect. All children may have rotavirus in their feces but the percentage of children developing diarrhea is highest at an age of 3 to 6 months and decreases steadily thereafter. Rotaviruses can survive in air and may remain on surfaces for several hours. They are thus often responsible for nosocomial infections. Rotavirus was first identified in cattle in 1969. The virulence of the strain and the age of the calf at infection are important in the pathogenesis of rotaviral infection in cattle. Replacement of villous enterocytes is slow in newborn calves. This means that newborn calves are susceptible to disease caused by strains that are only moderately virulent. They are, however, protected during the first days of life by antibodies transmitted via the colostrum. There is competition between the rate of replication of rotavirus and replacement of enterocytes in older animals so only more virulent strains cause diarrhea in six-week-old calves. Adult animals become resistant to disease, but not to infection. The rotavirus genome consists of 11 segments of double-stranded RNA. Genetic recombination between these segments occurs naturally and can be reproduced in vitro. Recombinants between human and bovine strains have been identified but the epidemiological importance of this is unknown. The genomic segments encode 6 structural proteins (VP) and 5 non-structural proteins (NSP). VP6, the major capsid antigen, present can be used to identify groups of rotaviruses. The presence of VP7 indicates that the virus belongs to the G (glycoprotein) group of serotypes. There are 14 G serotypes, 10 of which can infect humans. The four main G serotypes are G1 to G4, with G1 accounting for 60% of human serotypes. The presence of VP4 identifies the P (protease-sensitive) serotype. The serotypes have different geographic distributions with G1P8 responsible for more than 50% of epidemics worldwide. The WHO project for the control of rotaviral infections focuses on avoiding fecal contamination. This is achieved by ensuring high standards of food hygiene, sewage treatment and chlorinated running water and by introducing vaccination when vaccines become available. Recombinant animal (bovine or simian) and human rotaviruses are currently being tested in phase III studies. Attenuated live human viruses, including cold-adapted strains are being tested in phase I trials. The quadrivalent recombinant rhesuslhuman vaccine had only mild side-effects in children and was effective, giving 82-92% protection against severe diarrhea over two years and 50% protection on average. (ABSTRACT TRUNCATED)

Adult↗
PubMed2005

Experimental infection of pigtailed macaques with a simian rotavirus, YK-1.

Experimental rotavirus infection was investigated in pigtailed macaques to study the infectivity, immunity, and pathogenesis of rotavirus. A challenge virus, YK-1, was administered intragastrically to four seronegative macaques (age: 11-16 months). Although none of the monkeys developed diarrhea, an active infection occurred with high titers of rotavirus antigen detected in stools 2-10 days after challenge. These animals developed rotavirus-specific antibody responses similar to those seen following primary exposure to rotavirus. YK-1 was then inoculated in four seropositive macaques (age: 14-16 months). All animals shed viral antigen in their stool, but the titers and duration were significantly less when compared to seronegative macaques. When rechallenged 28 days after initial YK-1 challenge, the macaques demonstrated significant protection against reinfection. All seropositive animals developed a rise in rotavirus-specific serum and fecal antibodies during YK-1 challenge and rechallenge. To independently assess the role of age and preexisting IgG titers to rotavirus, a 4-month-old seronegative and 6-month-old seropositive macaque were inoculated with YK-1. The seronegative macaque shed high titers of virus for 9 days, while the seropositive macaque shed only 3 days and in low titer. These data suggest that a primate model of rotavirus infection using the YK-1 strain may be useful in examining the immune response and protection from infection in pigtailed macaques and indicate that levels and duration of shedding may provide a good measure of protection from natural infection and from that induced by oral or parenteral vaccines.

Animals↗
PubMed1997

Efficacy of the rhesus rotavirus-based quadrivalent vaccine in infants and young children in Venezuela.

BACKGROUND: Rotaviruses are the principal known etiologic agents of severe diarrhea among infants and young children worldwide. Although a rhesus rotavirus-based quadrivalent vaccine is highly effective in preventing severe diarrhea in developed countries, in developing countries its efficacy has been less impressive. We thus conducted a catchment study in Venezuela to assess the efficacy of the vaccine against dehydrating diarrhea. METHODS: In this randomized, double-blind, placebo-controlled trial, 2207 infants received three oral doses of the quadrivalent rotavirus vaccine (4x10(5) plaque-forming units per dose) or placebo at about two, three, and four months of age. During approximately 19 to 20 months of passive surveillance, episodes of gastroenteritis were evaluated at the hospital. RESULTS: The vaccine was safe, although 15 percent of the vaccinated infants had febrile episodes (rectal temperature, > or =38.1 degrees C) during the six days after the first dose, as compared with 7 percent of the controls (P<0.001). However, the vaccine gave 88 percent protection against severe diarrhea caused by rotavirus and 75 percent protection against dehydration, and produced a 70 percent reduction in hospital admissions. Overall, the efficacy of the vaccine against a first episode of rotavirus diarrhea was 48 percent. Horizontal transmission of vaccine virus was demonstrated in 15 percent of the vaccine recipients and 13 percent of the placebo recipients with rotavirus-positive diarrhea. CONCLUSIONS: In this study in a developing country, the quadrivalent rhesus rotavirus-based vaccine induced a high level of protection against severe diarrheal illness caused by rotavirus.

Antibodies, Viral↗
PubMed2005

Epidemiological profile and burden of rotavirus diarrhea in Vietnam: 5 years of sentinel hospital surveillance, 1998-2003.

For 5 years, we have conducted sentinel surveillance for rotavirus at 6 hospitals in 4 cities in Vietnam. Stool samples obtained from >10,000 children <5 years old who were admitted to the hospital with diarrhea have been screened for rotavirus. Overall, 55% of samples were positive, and there was little variability in rates of detection of rotavirus between sites (44%-62%). In Vietnam, the characteristics of rotavirus infection more closely resemble those seen in developed countries, rather than those seen in developing countries: children become infected at an older age, the percentage of stool samples in which rotavirus is detected is extremely high, and the rotavirus strains appear to be the common types, with fewer mixed infections occurring. It is estimated that 5300-6800 children <5 years old die of rotavirus infection each year in Vietnam, representing 8%-11% of all deaths in this age group (cumulative risk per child by age 5 years, 1 in 200 to 1 in 285). Additional studies are ongoing to document the economic cost of the disease and to assess the burden of both fatal cases and milder cases of disease. Study outcomes will provide information for future testing and potential use of a rotavirus vaccine.

Child, Preschool↗
PubMed2005

Rotavirus vaccines: targeting the developing world.

For the past 2 decades, rotavirus infection, the most common cause of severe diarrhea in children, has been a priority target for vaccine development. This decision to develop rotavirus vaccines is predicated on the great burden associated with fatal rotavirus disease (i.e., 440,000 deaths/year), the firm scientific basis for developing live oral vaccines, the belief that increased investment in development at this time could speed the introduction of vaccines in developing countries, and the appreciation that implementation of a vaccine program should result in a measurable decrease in the number of hospitalizations and deaths associated with rotavirus disease within 2-3 years. RotaShield (Wyeth-Ayerst), the first rotavirus vaccine licensed in the United States, was withdrawn after 9 months because of a rare association of the vaccine with the development of intussusception. In the developing world, this vaccine could still have had a measurable effect, because the benefits of preventing deaths due to rotavirus disease would have been substantially greater than the rare risk of intussusception. Two live oral vaccines being prepared by GlaxoSmithKline and Merck have completed large-scale clinical trials. The GlaxoSmithKline vaccine has been licensed in Mexico and the Dominican Republic, and the Merck vaccine could be licensed in the United States within 1 year; several other candidate vaccines are in earlier stages of testing. However, many challenges remain before any of these vaccines can be incorporated into childhood immunization programs in the developing world. First, vaccine efficacy, which has already been demonstrated in children in industrialized and middle-income countries, needs to be proven in poor developing countries in Africa and Asia. The safety of vaccines with regard to the associated risk of intussusception must be demonstrated as well. Novel financing strategies will be needed to ensure that new vaccines are affordable and available in the developing world. Decision makers and parents in developing countries need to know about this disease that has little name recognition and is rarely diagnosed. Finally, for the global effort toward the prevention of rotavirus disease to be successful, special efforts will be required in India, China, and Indonesia, because one-third of all deaths due to rotavirus disease occur in these countries, and because these countries depend almost entirely on vaccines manufactured domestically.

Administration, Oral↗
PubMed2005

Epidemiology and burden of rotavirus diarrhea in Thailand: results of sentinel surveillance.

Diarrhea remains an important cause of morbidity and mortality among children in Thailand, with >1 million cases reported in 2002. In anticipation of the development of vaccines against rotavirus, we evaluated the disease burden associated with rotavirus infection in Thai children and evaluated the rotavirus serotypes now circulating in Thailand. Diarrhea surveillance was conducted at 6 Thai hospitals in different geographic areas. Community-based surveillance was conducted in Huaykrajao District, Kanchanaburi Province. During the 24 months of surveillance, 4057 children were admitted to the 6 participating hospitals, and 1950 stool samples were collected. Of these stool samples, 43% (838) were positive for rotavirus. All rotavirus-positive stool samples were evaluated to identify their serotypes; 54.8% of samples were of serotype G9, which was predominant each year. Other identified rotavirus serotypes included G2, G4, G1, and G3 (17.2%, 5.3%, 0.8%, and 0.1% of isolates, respectively). Approximately one-half of the children hospitalized with rotavirus diarrhea were <1 year old. Community surveillance showed the proportion of cases of rotavirus diarrhea in the community to be much lower than that in the hospitalized population (12.2% vs. 43.0%).

Diarrhea↗
PubMed2006

Vaccines against rotavirus and human papillomavirus (HPV).

OBJECTIVE: To briefly review strategies aimed at the development of rotavirus and HPV vaccines, with emphasis on the current status of studies assessing the safety, reactogenicity, immunogenicity and efficacy of recently developed vaccines. SOURCES OF DATA: This review focuses on articles published from 1996 to 2006, mainly those from the last five years, with special emphasis on data obtained from recently completed studies involving a new live attenuated human rotavirus vaccine and a virus-like particle (HPV) vaccine. SUMMARY OF THE FINDINGS: Strategies for developing rotavirus vaccines ranged from Jennerian approaches to the new human-derived rotavirus vaccine. Currently, two rotavirus vaccines are recognized as both efficacious and safe: a pentavalent human-bovine reassortant vaccine and a vaccine derived from an attenuated rotavirus of human origin. The second of these has been evaluated in more than 70,000 infants all over the world. Prophylactic vaccines against HPV have been tested in more than 25,000 young individuals around the world. Results from phase II and III clinical studies indicate that such vaccines against the most common types of HPV, those linked to both genital warts and 70% of cervical cancers, are safe and highly efficacious. CONCLUSIONS: A future rotavirus immunization program covering 60 to 80% of infants worldwide is likely to reduce by at least 50% the number of rotavirus-associated hospitalizations and deaths. It is also reasonable to expect that implementation of HPV prophylactic vaccines will reduce the burden of the HPV-related diseases that presently impact millions of people around the world.

Animals↗
PubMed2000

Rotavirus serotypes: classification and importance in epidemiology, immunity, and vaccine development.

The development and implementation of safe and effective vaccines to prevent the enormous health burden of rotavirus-associated disease is a global public health goal. Human rotaviruses, the major aetiological agents of severe infantile diarrhoea worldwide, display surprisingly diverse and complex serotypic specificities. Ten VP7 serotypes and 7 VP4 serotypes have so far been detected. An increasing number of observations, obtained from analyses of (i) natural rotavirus infections in infants and young children, (ii) experimental rotavirus infections in laboratory animals, and (iii) extensive rotavirus vaccine field trials performed in different populations of various parts of the world, appears to support the concept that serotype-specific antibodies to rotaviruses play an important role in protection against rotavirus-associated illnesses. Thus, the first licensed rotavirus vaccine (RRV-based quadrivalent vaccine) was designed to cover the epidemiologically important VP7 serotype 1, 2, 3, and 4.

Antibodies, Viral↗
PubMed2000

Rotavirus vaccines.

The past few years have seen important developments in understanding the epidemiological and virological characteristics of rotaviruses, and rapid progress has been made in rotavirus vaccine development, but further challenges remain before a vaccine is introduced into widespread use. The licensure of the first rotavirus vaccine, a tetravalent rhesus-based rotavirus vaccine, in the United States in 1998, marked a significant advance in preventing the morbidity associated with rotavirus diarrhea. The association between the tetravalent rhesus-based rotavirus vaccine and intussusception has created significant hurdles as well as new opportunities to study the pathogenesis of rotavirus and rotavirus vaccine infection. Several other rotavirus vaccine candidates are in late stages of development, and results from trials have been encouraging.

Journal Article↗
PubMed2001

Rotavirus epidemiology and surveillance.

There is extensive antigenic and genomic diversity among co-circulating human rotaviruses. They are differentiated into groups, subgroups and types. There are at least 7 groups (A-G) and 4 subgroups within group A. To distinguish types within group A, a dual classification system has been established with the glycoprotein VP7 defining G types, and the protease-sensitive protein VP4 defining P types. At least 14 G types and more than 20 P types have been distinguished, of which at least 10 G types and at least 11 P types have been found in humans. Using the typing system, the complex molecular epidemiology of rotaviruses was investigated. Rotaviruses of different G and P types co-circulate. The main types found are G1P1A[8], G2P1B[4], G3P1A[8], G4P1A[8]; their relative incidence rates change over time in any one location and are different at the same time between different locations. Viruses with G/P constellations such as G1P1B[4] and G2P1A[8] are mostly natural reassortants of the co-circulating main virus types emerging after double infection of hosts. Viruses carrying G and or P types not represented in the four most common types, e.g. G8P[8], G1P[6] or G9P[6], could be introduced into the population by reassortment with animal viruses, or directly from animals or exotic human sources. Naturally circulating rotaviruses constantly undergo point mutations which can be used to classify lineages and sublineages within types. The full significance of human infections with group B and C rotaviruses remains to be established. Surveillance of rotavirus types in different parts of the world is essential to monitor the emergence of new types or of new G/P constellations which may predominate over time. The efficacy and effectiveness of any future rotavirus vaccine may differ depending on the predominant natural strain types. Detailed epidemiological and molecular surveillance data should be utilized to study the transmission dynamics of rotaviruses.

Amino Acid Sequence↗
PubMed2002

Circulation of the novel G9 and G8 rotavirus strains in Nigeria in 1998/1999.

An epidemiological survey investigating the prevalence of rotavirus infection in infants and young children with acute diarrhoea was undertaken in Jos State, Nigeria, between January 1998 and April 1999. In total, 672 faecal specimens were collected from children aged between 1 and 60 months with acute infantile gastroenteritis. The 10-20% stool suspensions were examined by an ELISA for the presence of group A rotavirus antigen (Rotavirus IDEIA, Dako, UK). Only 116 specimens (17.3%) were positive for the group A rotavirus antigen detected by this ELISA. The rotavirus-positive specimens were analysed with monoclonal antibodies specific for rotavirus VP6 subgroup I and II, and for VP7 serotypes G1-G4, G8, and G9. Of the rotavirus strains that could be subgrouped, VP6 subgroup I and II strains circulated at similar levels. Amongst the strains that could be serotyped, VP7 G9 strains predominated occurring in 17 cases, with G3 (n = 10) and G1 (n = 9) strains occurring in lower numbers. Four G8 strains were detected and only one G2 and no G4 strains were identified. This report extends the description of the global distribution of G9 rotavirus strains.

Antibodies, Monoclonal↗
PubMed1988

Systemic lymphoproliferative responses to rotavirus.

In comparison with healthy adults, elderly patients and patients who had received renal transplants had significantly lower lymphoproliferative responses to rotavirus (P = 0.04, P = 0.002, respectively) and phytohaemagglutinin (P = 0.001). However, following acute rotavirus infection, elderly persons mounted good lymphoproliferative and specific antibody responses to rotavirus. No lymphoproliferative response or specific antibody to rotavirus was detected in a child with cartilage hair hypoplasia. In cord blood samples, specific antibodies were detected in the absence of a lymphoproliferative response to rotavirus. Increases in lymphoproliferative responses as well as specific antibodies were not detected in immune adult recipients of a human rotavirus vaccine (RIT 4375), but a recipient of a bovine vaccine (RIT 4237) had an increase in lymphoproliferative response to rotavirus between 13 and 28 days postvaccination. Stimulation indices for both rotavirus and phytohaemagglutinin within the vaccine groups were comparable to the healthy laboratory personnel group.

Adult↗
PubMed1988

Investigation of hospital-acquired rotavirus gastroenteritis using RNA electrophoresis.

Rotavirus is a common cause of diarrhoea both in the community and in the hospital. Because of this, it may be difficult to determine whether crossinfection has occurred in the hospital, an important finding as review of hygienic techniques and ward closure may be indicated. We therefore investigated the use of Polyacrylamide gel electrophoresis (PAGE) of the rotavirus RNA genome as a means of distinguishing between rotavirus strains in order to assess its role in the evaluation of apparent hospital-acquired rotavirus diarrhoea. Suspected examples of hospital-acquired rotavirus gastroenteritis were studied on an infectious diseases ward and a general infant ward. PAGE analysis demonstrated that crossinfection had not occurred on the infectious diseases ward, even though this was indicated clinically; a single source outbreak involving 11 patients was confirmed on the general infant ward, as all cases showed an identical rotavirus electropherotype. Following ward closure an endemic rotavirus electropherotype was detected, which affected 17 patients over a 3-month period. Electrophoresis of rotavirus RNA is a useful and practical technique in the analysis of hospital-acquired gastroenteritis and can indicate appropriate clinical action.

Cross Infection↗
PubMed1991

Rotavirus infection of the oropharynx and respiratory tract in young children.

Oropharyngeal aspirates were obtained from 89 infants hospitalized with respiratory illnesses accompanied or not by diarrhea and 33 control patients without the diseases. Rotavirus was detected from 25 of these patients by immunocytology, isolation of the virus in cultures of MA104 cells, or both. None of the control patients gave a positive result. The infection involves squamous cells and globlet cells probably originating from the oropharynx, and ciliated columnar epithelial cells from the respiratory tract. The virus from 2 specimens was propagated by repeatedly passaging in the cultures and found to have characteristic morphology of rotavirus. The electrophoretic patterns of the viral RNA extracted from them are closely similar to those obtained with the rotavirus genome extracted from the stool of the same patients. Repeated stool specimens were also obtained, and sera were paired from some of these subjects. All but one of the patients who gave a positive virology for their aspirates also showed a significant rise in the titres of common group A rotavirus antibody, neutralizing antibody against one or more of serotypes of rotavirus, or both. Patients who excreted rotavirus in their stools were younger and had significantly lower titres of rotavirus antibodies in their acute sera, than those who shedded the virus in the oropharynx but did not excrete the virus in repeated stool specimens. The prevalence of rotavirus in the oropharyngeal aspirates from these patients surpassed that of adenovirus, respiratory syncytial virus, influenza virus, and herpes simplex virus combined.

Antibodies, Viral↗
PubMed1992

Passive immunizations of suckling mice and infants with bovine colostrum containing antibodies to human rotavirus.

After immunizing 8-month pregnant Holstein cows with the human rotavirus MO strain, cow colostrum containing neutralizing antibody to four different serotypes of human rotavirus, designated Rota colostrum, was obtained. Oral inoculation of human rotavirus MO strain into 5-day-old BALB/c mice causes gastroenteritis characterized by diarrhea. Using this small animal model, passive protection of suckling mice against human rotavirus infection was achieved with the use of Rota colostrum. Rota colostrum completely protected against rotavirus infection, but purified IgG and IgA obtained from Rota colostrum were unable to protect against infection. After grouping randomly 20 infants from a baby care center, 10 infants received 20 ml of Rota colostrum per day for 2 weeks and 10 control infants did not. Rotavirus-associated diarrhea developed in 7 of 10 infants in the control group. None of the three infants in the every day recipient group of Rota colostrum had such symptoms, and one of three infants in the every other day recipient group developed rotavirus-induced diarrhea. All four infants who received Rota colostrum after symptoms appeared developed diarrhea. Oral administration of Rota colostrum seems to be an effective and safe means of preventing diarrhea caused by human rotavirus infection.

Age Factors↗
PubMed1994

Serological response to rotavirus infection in newborn infants.

We report the identification of rotavirus in stools of newborn infants at the "Hospital Materno Infantil de Caricuao" (HMIC) as well as the infants' serological responses to various rotavirus strains. The serological responses of another group of rotavirus-positive neonates studied previously at the "Maternidad Concepcion Palacios" (MCP) hospital was also evaluated. Fifty-four of 266 (20%) newborns examined at HMIC shed rotavirus. The infection rate was higher among infants admitted to the nursery (75%) than in those "rooming in" with their mothers (7%) (P < .01). Eleven of the 54 neonates (20%) had diarrhea; seven of them experienced mild, short-lived episodes, whereas five had frequent diarrhea bouts or diarrhea lasting for over 3 days; the remaining 43 infants were asymptomatic. Twenty-seven of 28 rotavirus specimens tested at HMIC had VP7 serotype 4 specificity and one belonged to VP7 serotype 1; VP4 typing performed on 24 of the viruses by RNA hybridization showed these viruses to be similar to the M37 strain, a rotavirus previously associated with asymptomatic infections in newborns at MCP. IgA seroresponses were detected in eight of 11 infants born at HMIC (73%), but most failed to developed neutralization responses to homologous or heterologous strains. Newborn infants who had shed the M37 rotavirus strain at MCP reacted similarly: 16 of 24 (67%) developed a rotavirus IgA rise, but only 29% developed a neutralization response.

Antibodies, Viral↗
PubMed2005

Changing epidemiology of rotavirus G-types circulating in Hong Kong, China.

Group A rotaviruses are the most common cause of severe diarrhoeal disease in young children worldwide. The development of a vaccine is advocated by the World Health Organization. Obtaining local baseline information regarding rotavirus strain variation is important to ensure matching of circulating and vaccine strains. The current study was undertaken to determine the epidemiology of rotavirus G-types in Hong Kong in anticipation of a vaccination program. From 2001 to 2002 over a period of one year, diarrhoeal stool specimens known to be positive for rotavirus were subjected to G-typing by reverse transcriptase-polymerase chain reaction using nested type-specific primers. Rotavirus G-type distribution was correlated with patient demographics. Among 747 rotavirus positive stool specimens, 723 strains could be G-typed as G1 (302, 40.4%), G2 (128, 17.1%), G3 (231, 30.9%), G4 (24, 3.2%), and G9 (38, 5.1%). G1 strains were found predominantly in those 5 years old or younger (P < 0.0001), while G2 strains were more prevalent among those over 5 years of age (P < 0.001). When compared with similar studies in 1983 to 1984 and 1999 to 2000, there were significant changes in the prevalence of various G-types, with consistent detection of G9 strains in the current study. It is concluded that rotavirus G-type distribution in Hong Kong has varied with time. Continuous monitoring of the epidemiology of rotavirus is important, especially in anticipation of the introduction of a vaccine, in order to document its impact and to ensure its continued effectiveness.

Adolescent↗