Detection Rate Of Rotavirus Research Articles

Global Mortality Associated with Rotavirus Disease among Children in 2004

As new rotavirus vaccines are being introduced in immunization programs, global and national estimates of disease burden, especially rotavirus-associated mortality, are needed to assess the potential health benefits of vaccination and to monitor vaccine impact. We identified 76 studies that were initiated after 1990, lasted at least 1 full year, and examined rotavirus among >100 children hospitalized with diarrhea. The studies were assigned to 5 groups (A-E) with use of World Health Organization classification of countries by child mortality and geography. For each group, the mean rotavirus detection rate was multiplied by diarrhea-related mortality figures from 2004 for countries in that group to yield estimates of rotavirus-associated mortality. Overall, rotavirus accounted for 527,000 deaths (95% confidence interval, 475,000-580,000 deaths) annually or 29% of all deaths due to diarrhea among children <5 years of age. Twenty-three percent of deaths due to rotavirus disease occurred in India, and 6 countries (India, Nigeria, Congo, Ethiopia, China, and Pakistan) accounted for more than one-half of deaths due to rotavirus disease. The high mortality associated with rotavirus disease underscores the need for targeted interventions, such as vaccines. To realize the full life-saving potential of vaccines, it will be vital to ensure that they reach children in countries with high mortality. These baseline figures will allow future assessment of vaccine impact on rotavirus-associated mortality.

Detection of enteric viruses in rectal swabs from children with acute gastroenteritis attending the pediatric outpatient clinics in Sapporo, Japan

Background Gastroenteritis is a world-wide disorder. Numerous studies to identify causative viral agents have been reported for hospitalized patients but there are only a few for outpatients with mild symptoms who are usually managed in the outpatient clinics. Objectives Our aim was to clarify the epidemiological and clinical characteristics of acute gastroenteritis in children who visited the outpatient clinics with various complaints suggestive of gastroenteritis. Study design From December 2003 to December 2005, 877 rectal swabs were collected from patients attending outpatient clinics in Sapporo, Japan. Viral genomes of major five enteric viruses (rotavirus, norovirus, adenovirus, astrovirus and sapovirus) and bocavirus were investigated by RT-PCR or PCR. Results At least one viral agent was found in 326 (37.2%) cases of the 877 studied. Rotaviruses were the most prevalent and were detected in 143 (16.3%) followed by norovirus in 116 (13.2%), adenovirus in 42 (4.8%), astrovirus in 40 (4.6%) and sapovirus in 15 (1.7%) cases. Bocavirus was detected in only 4 (0.5%) cases. Frequent diarrhea and frequent vomiting were prominent in rotavirus and norovirus infection, respectively. Conclusions The prevalence of each enteric virus in outpatients resembled that previously estimated in hospitalized patients, although the detection rate of rotavirus was slightly low. The contribution of bocavirus appears to be small.

Rotavirus Genotype Distribution after Vaccine Introduction, Rio de Janeiro, Brazil

Brazil introduced rotavirus vaccination in March 2006. We studied 133 rotavirus-positive fecal samples collected from February 2005 through December 2007. Genotype G2P[4] was found in 1.4% of samples in 2005, in 44% in 2006, and in 96% in 2007. Rotavirus detection rate decreased from 38% in 2005 to 24% in 2007 (p = 0.012).

Active, Population-Based Surveillance for Severe Rotavirus Gastroenteritis in Children in the United States

Routine vaccination of US infants against rotavirus was implemented in 2006, prompting the Centers for Disease Control and Prevention New Vaccine Surveillance Network to begin population-based acute gastroenteritis surveillance among US children<3 years of age. This surveillance system establishes baseline estimates of rotavirus disease burden and allows for the prospective monitoring of rotavirus vaccination impact. Eligible children with acute gastroenteritis (>or=3 episodes of diarrhea and/or any vomiting in a 24-hour period) who were hospitalized, were seen in emergency departments, or visited selected outpatient clinics in 3 US counties during the period of January through June 2006 were enrolled. Epidemiological and clinical information was obtained through parental interview and medical chart review, and stool specimens were tested for rotavirus with enzyme immunoassays. Rotavirus-positive specimens were genotyped by using reverse transcription-polymerase chain reaction assays. Stool specimens were collected from 516 of the 739 enrolled children with acute gastroenteritis (181 inpatient, 201 emergency department, and 134 outpatient) and 44% tested positive for rotavirus (227 of 516 specimens). The most common strain was P[8]G1 (84%), followed by P[4]G2 (5%) and P[6]G12 (4%). None of the 516 children had received rotavirus vaccine. The rotavirus detection rate was 50% for hospitalized acute gastroenteritis cases, 50% for emergency department visits, and 27% for outpatient visits. Rotavirus-related acute gastroenteritis cases were more likely than non-rotavirus-related acute gastroenteritis cases to present with vomiting, diarrhea, fever, and lethargy. Directly calculated, population-based rates for rotavirus hospitalizations and emergency department visits were 22.5 hospitalizations and 301.0 emergency department visits per 10 000 children<3 years of age, respectively. A sentinel outpatient clinic visit rate of 311.9 outpatient visits per 10,000 children<3 years of age was observed. Population-based, laboratory-confirmed rotavirus surveillance in the final rotavirus season before implementation of the US rotavirus vaccine program indicated a considerable burden of disease on the US health care system.

Molecular Epidemiologic Analysis of Group A Rotaviruses in Children with Diarrhea in Wuhan City, China, 2007

Background: Rotaviruses are the major etiological cause of acute viral gastroenteritis in infants and young children worldwide, primarily in developing countries, producing a significant disease burden. Methods: To describe epidemiologic features and genetic characteristics of group A rotaviruses causing diarrhea in children and to estimate the relatedness or origin of the rotaviruses, a survey was conducted in Wuhan, China, 2007. A total of 889 stool specimens from diarrheal patients under 14 years old from Wuhan Children’s Hospital were analyzed. Many symptoms such as vomit, cough, fever, dehydration were marked. The positive rotavirus specimens was determined by PAGE and rapid immunochromatographic assay. Results: A total of 236 positive specimens performed further genetic analysis. Genotyping of rotavirus was determined by RT-PCR. By sequencing and phylogenetically assigning, two G9 strains were found out. In total, rotavirus detection rate of all stool specimens is 26.55% (236/889). By PAGE and rapid immunochromatographic assay, the detection coincidence rate was 86.42%. Unfortunately, the detection rate was independent of the symptoms. There were extremly significant differences of the detection rates in different age groups ( 2 = 33.53, P < 0.01). The detection rates in the winter season (42-64%), from October to December, were significantly higher than the other seasons(P < 0.05). Throughout the study period, P[8] was the most frequent P serotype (88.9%), and G3 was the most frequent G serotype (75.3%), and was mostly associated with VP4 genotype P[8](68.4%). And the G-type/P-type combination G3P[8] was the most common, followed by G1P[8], G2P[4] and G3P[6]. G1 +G3P[8], G3 +G9P[8], G2 +G3P[4] and other mixed G/P types were detected also. VP7 gene sequences of G9 rotaviruses were detected out by sequencing for two strains, showed extremely high sequence identities (99—100%) to each other and to a few G9 rotavirus strains reported in Asia. Conclusion: In our present study, the rotavirus-positive rate in children specimens was 26.55% in total. The monthly prevalence of rotavirus infection showed significant winter seasonality. It was evident that the G3P[8] rotaviruses were the most prevalent throughout the study period. These findings suggest that transmission of the G3 rotaviruses might have occurred endemically in Wuhan. The two G9 strains were phylogenetically assigned to lineage 3.

Rotavirus P[4]G2 in a Vaccinated Population, Brazil

We acknowledge the comments by Patel et al. (1) and by Linhares and Velazquez (2) about our article that documented the presence of a single rotavirus genotype (P[4]G2) in Aracaju, northeastern Brazil, after the introduction of a human, monovalent rotavirus vaccine (3). Both letters emphasize that the predominance of P[4]G2 may be caused by a natural genotype variation unrelated to vaccination. We agree that our observation could be explained by natural variation of circulating rotavirus genotypes in the region, but an alternative possibility is that the introduction of the G1P[8] rotavirus vaccine into the childhood immunization schedule created conditions in which P[4]G2 strains had a selective advantage over strains with which the vaccine shares G type, P type, or both. According to a systematic review of rotavirus genotypes reported in the 25 years preceding introduction of the vaccine in Brazil, the prevalence of P[4]G2 strains varied from 19% (1986–1995) to 12% (1996–2000) to 1% thereafter, thus not reaching the detection rate we observed in Aracaju (R.Q. Gurgel et al., unpub data). Furthermore, in the ensuing 8-month period, no genotype other than P[4]G2 had been detected in Aracaju, suggesting that our initial findings were not spurious (R.Q. Gurgel et al., unpub data). In addition, in a separate study we conducted in Recife, a city 500 km north of Aracaju, we observed a significant increase in the proportion of G2 strains detected from 47% (21/45) during the 3-month period immediately after vaccine introduction (March 2006–May 2006) to 100% (11/11) during the same 3-month period 1 year after the vaccine introduction (March 2007–May 2007) (4). We believe that our findings are consistent with results of field trials that indicated that the vaccine provided relatively less protection against P[4]G2 strains than against other rotavirus strain types (5). The beneficial impact of rotavirus vaccination in northeastern Brazil is reflected in the reduction of the detection rate of rotavirus among severe diarrhea cases in our study in Recife, which fell from 27% (45/166 cases) to 5.0% (11/221 cases) in the postvaccine 3-month reporting periods, respectively (4). Our data from Aracaju are indicative of heterotypic protection, although this is not statistically significant (1), against P[4]G2 strains. Further postlicensure studies in Brazil are required to document continuing effectiveness of the national vaccination program as well as to closely monitor the circulating rotavirus strain types (6).

Rotavirus P[4]G2 in a Vaccinated Population, Brazil

We acknowledge the comments by Patel et al. (1) and by Linhares and Velazquez (2) about our article that documented the presence of a single rotavirus genotype (P[4]G2) in Aracaju, northeastern Brazil, after the introduction of a human, monovalent rotavirus vaccine (3). Both letters emphasize that the predominance of P[4]G2 may be caused by a natural genotype variation unrelated to vaccination. We agree that our observation could be explained by natural variation of circulating rotavirus genotypes in the region, but an alternative possibility is that the introduction of the G1P[8] rotavirus vaccine into the childhood immunization schedule created conditions in which P[4]G2 strains had a selective advantage over strains with which the vaccine shares G type, P type, or both. According to a systematic review of rotavirus genotypes reported in the 25 years preceding introduction of the vaccine in Brazil, the prevalence of P[4]G2 strains varied from 19% (1986–1995) to 12% (1996–2000) to 1% thereafter, thus not reaching the detection rate we observed in Aracaju (R.Q. Gurgel et al., unpub data). Furthermore, in the ensuing 8-month period, no genotype other than P[4]G2 had been detected in Aracaju, suggesting that our initial findings were not spurious (R.Q. Gurgel et al., unpub data). In addition, in a separate study we conducted in Recife, a city 500 km north of Aracaju, we observed a significant increase in the proportion of G2 strains detected from 47% (21/45) during the 3-month period immediately after vaccine introduction (March 2006–May 2006) to 100% (11/11) during the same 3-month period 1 year after the vaccine introduction (March 2007–May 2007) (4). We believe that our findings are consistent with results of field trials that indicated that the vaccine provided relatively less protection against P[4]G2 strains than against other rotavirus strain types (5). The beneficial impact of rotavirus vaccination in northeastern Brazil is reflected in the reduction of the detection rate of rotavirus among severe diarrhea cases in our study in Recife, which fell from 27% (45/166 cases) to 5.0% (11/221 cases) in the postvaccine 3-month reporting periods, respectively (4). Our data from Aracaju are indicative of heterotypic protection, although this is not statistically significant (1), against P[4]G2 strains. Further postlicensure studies in Brazil are required to document continuing effectiveness of the national vaccination program as well as to closely monitor the circulating rotavirus strain types (6).

Viral gastroenteritis and diversity of rotavirus strains in Colombian children: a systematic review

To determine the epidemiological profile of viruses associated with acute gastroenteritis in children younger than 5 years of age and the distribution of rotavirus genotypes circulating in Colombia. We conducted a review of 23 studies published in Spanish and English, plus an analysis of the detection rates of rotavirus as well as other viruses associated with acute gastroenteritis in young children from 1984 to 2006 in the three Colombian regions. This review also included the only two studies conducted to date (published between 2004 and 2006) reporting G-P rotavirus strains using RT-PCR. The median detection rate of group A Rotavirus was 35.2% (range, 2.2%-57.4%) and those for Calicivirus, Astrovirus and Adenovirus 40/41 were 10.4%, 2.7% and 1.35%, respectively. The more commonly reported rotavirus GP combination, G3P [8] (32.7%) was more frequently documented than both G1P [8] (24.7%) and G2P [4] (22.9%). The G9 genotype, which is considered emergent, was also reported. Group A Rotavirus was frequently associated with diarrhoea in children from the three regions. There was regional variation in rotavirus detection rates. Continual surveillance is needed to inform diarrhoea prevention programs as well as to provide information about the occurrence of native rotavirus strains.

Symptomatic and Subclinical Infection with Rotavirus P[8]G9, Rural Ecuador

During the past decade, rotavirus genotype G9 has spread throughout the world, adding to and sometimes supplanting the common genotypes G1-G4. We report evidence of this spread in a population sample within rural Ecuador. A total of 1,656 stool samples were collected from both patients with diarrhea and from asymptomatic residents in 22 remote communities in northwestern Ecuador from August 2003 through February 2006. Rotavirus was detected in 23.4% of case-patients and 3.2% of controls. From these 136 rotavirus-positive samples, a subset of 47 were genotyped; 72% were of genotype G9, and 62% were genotype P[8]G9. As a comparison, 29 rotavirus-positive stool samples were collected from a hospital in Quito during March 2006 and genotyped; 86% were of genotype P[8]G9. Few countries have reported P[8]G9 rotavirus detection rates as high as those of the current study. This growing prevalence may require changes to current vaccination programs to include coverage for this genotype.

Frequency of Enteropathogen Detection in Suckling and Weaned Pigs with Diarrhea in Japan

Fecal samples from suckling (n=153) and weaned (n=116) piglets with diarrhea in Japan were examined for shedding of viral, bacterial, and parasitic pathogens using culture, microscopic, and polymerase chain reaction methods. In suckling piglets, diarrhea was attributed to infection with a single etiologic agent in 60.8% of cases and with combinations of agents in 22.2%. In weaned piglets, diarrhea was attributed to a single etiologic agent in 43.1% and to combinations of agents in 47.4% of cases. Rotavirus was the most prevalent agent in suckling (67.3%) and weaned (65.5%) piglets. The detection of other pathogens was associated with age of the animals examined. Coccidia were predominantly isolated from suckling piglets, whereas Escherichia coli was found predominantly in weaned piglets. Although a relationship was not observed between detection rate of rotavirus and age of piglets, a single group of rotavirus was detected in 87.5% of suckling piglets whereas multiple groups were detected in 51.6% of weaned piglets. The results of this study confirm that diarrhea in piglets can, to a variable degree, be causally associated with multiple agents. Additionally, these results suggest reasons why this syndrome can be difficult to control.

TEMPORAL AND GEOGRAPHIC TRENDS OF ROTAVIRUS ACTIVITY IN THE UNITED STATES, 1997–2004

Rotavirus (RV) has a characteristic seasonal pattern in the 48 contiguous states of the continental United States, and climatologic factors have been implicated though not confirmed. Since 1997, three significant events occurred, including strong El Niño and La Niña climatologic phenomena, and the brief introduction of a rotavirus (RV) vaccine. We examined trends in RV activity in the continental United States between 1997 and 2004, using data from a network of over 70 laboratories that voluntarily report weekly RV detection rates within the National Respiratory and Enteric Virus Surveillance System (NREVSS). Analysis of NREVSS data indicates characteristic winter activity that begins in the Southwest in December or January, moves across the country, and ends in the Northeast in April or May. This pattern was not affected by the brief use of RV vaccine nor by periods of climate change associated with the El Niño and La Niña phenomena. The temporal and geographic pattern of RV spread in the United States has persisted since its initial description and defies easy explanation. An impact of the RV vaccine was not observed, either because of the limited uptake of the vaccine or the inherent variability of the system. NRVESS permits a gross assessment of RV geographic and temporal trends in the United States, but underscores the need for additional assessment mechanisms.

Sentinel Hospital Surveillance for Rotavirus Diarrhea in Taiwan, 2001–2003

We examined the epidemiological profile of rotavirus infection among children hospitalized for diarrhea in Taiwan, to assess the burden of this disease. From 1 April 2001 through 31 March 2003, children <5 years old with gastroenteritis admitted to 4 sentinel hospitals were enrolled in a surveillance study and had stool specimens tested for the presence of rotavirus, enteric adenovirus, and the bacterial pathogens for which routine screening is performed. For 52% of patients, a recognized enteric pathogen was identified, including rotavirus (43% of patients), bacteria (11%), enteric adenovirus (2.5%), and a mixture of pathogens (3.9%). Rotavirus was detected year-round, but great month-to-month variability made it difficult to identify a distinct seasonal pattern. Rotavirus disease was most common among children 7-23 months old, but the rate of rotavirus detection varied little between the youngest and oldest age groups. The novel strain P[8]G9 was detected most commonly (37% of strains), followed by strains P[8]G1 (31%), P[4]G2 (10%), P[8]G3 (9.3%), and P[8]G4 (3.7%). Rotavirus infection is the most important cause of diarrhea among hospitalized children in Taiwan, and a rotavirus vaccination program for young children might significantly reduce this problem.

Epidemiological features of rotavirus infection in Goiânia, Goiás, Brazil, from 1986 to 2000.

A total of 2,605 faecal specimens from children up to 10 years old with or without diarrhoea were collected. Samples were obtained from 1986 to 2000 in hospitals, outpatient clinics and day-care centers in Goiânia, Goiás. Two methodologies for viral detection were utilized: a combined enzyme immunoassay for rotavirus and adenovirus and polyacrylamide gel electrophoresis. Results showed 374 (14.4%) faecal specimens positive for Rotavirus A, most of them collected from hospitalized children. A significant detection rate of rotavirus during the period from April to August, dry season in Goiânia, and different frequencies of viral detection throughout the years of study were also observed. Rotavirus was significantly related to hospitalization and to diarrhoeal illness in children up to 24 months old. This study reinforces the importance of rotavirus as a cause of diarrhoea in children and may be important in regards to the implementation of rotavirus vaccination strategies in our country.

Rotavirus diarrhea disease burden in Peru: the need for a rotavirus vaccine and its potential cost savings.

To assess the disease burden of rotavirus diarrhea in Peru as well the need for and the potential cost savings with a rotavirus vaccine in that country. To assess the burden of rotavirus diarrhea in Peru, we reviewed published and unpublished reports where rotavirus was sought as the etiologic agent of diarrhea in children. Rotavirus detection rates obtained from these studies were combined with diarrhea incidence rates from a number of national surveys in order to estimate both the burden of rotavirus diarrhea in the country and its associated medical costs. Rotavirus is a significant cause of morbidity and mortality in Peruvian children. In their first 5 years of life, an estimated 1 in 1.6 children will experience an episode of rotavirus diarrhea, 1 in 9.4 will seek medical care, 1 in 19.7 will require hospitalization, and 1 in 375 will die of the disease. Per year, this represents approximately 384,000 cases, 64,000 clinic visits, 30,000 hospitalizations, and 1,600 deaths. The annual cost of medical care alone for these children is approximately US$ 2.6 million--and that does not take into account the indirect or societal costs of the illness and the deaths. Rotavirus immunization provides the prospect of decreasing the morbidity and mortality from diarrhea in Peru, but a vaccine regimen would have to be relatively inexpensive, a few dollars or less per child. Future cost-effectiveness analyses should explore the total costs (medical as well as indirect or societal) associated with rotavirus diarrhea. Newly licensed vaccines should be tested according to both their ability to avert deaths and their efficacy with fewer than three doses. All three of these factors could increase the cost savings associated with a rotavirus vaccine.

Rotavirus-associated medical visits and hospitalizations in South America: a prospective study at three large sentinel hospitals.

Knowledge of the impact of rotavirus-associated disease on the health care systems of South America can aid in defining strategies for diagnosis, management and prevention. Up to date information on the impact of rotavirus disease in South America is scarce. To determine prospectively the impact of rotavirus disease as a cause of medical visits and hospitalizations at three large sentinel pediatric hospitals in Argentina, Chile and Venezuela. A 2-year prospective surveillance for rotavirus-associated medical visits and hospitalizations was conducted during 1997 through 1998 at three large sentinel public hospitals, one each in Argentina, Chile and Venezuela. A common surveillance protocol was implemented at the three sites, and a representative number of nonbloody diarrhea stool samples from children <36 months of age were tested for rotavirus by enzyme-linked immunosorbent assay. For our target age group, acute diarrhea-associated medical visits/hospitalizations represented 41%/2%, 5%/6% and 9%/13% of all medical visits/all hospitalizations at the Argentinean, Chilean and Venezuelan sites, respectively (P < 0.001 for difference among the three sites). Rotavirus detection rates among a total of 5,801/1,256 medical visit/hospitalization diarrhea stool samples tested were 39%/71% in Argentina, 34%/47% in Chile and 29%/38% in Venezuela (P < 0.01 by chi square for difference among the three sites). Rotavirus was associated with a mean of 1.5, 1.8 and 3% of total medical visits and 1.6, 2.8 and 5% of hospitalizations among children <36 months of age at the Argentinean, Chilean and Venezuelan sites, respectively. Seasonality was evident for medical visits at all three sites (although less striking in Chile) with peak activity occurring between November and May. Rotavirus-associated hospitalizations had a marked peak in Venezuela, represented largely by short stays, but not in Argentina and Chile. Rotavirus was a significant cause of medical visits at all three sentinel sites. Rotavirus caused less hospitalizations than previously reported in Argentina and Chile. On the basis of our findings we estimate that approximately 106,000/ 21,000, 48,000/8,000 and 98,000/31,000 rotavirus-associated medical visits/hospitalizations occur yearly in Argentina, Chile and Venezuela, respectively.

Rotavirus and concurrent infections with other enteropathogens in neonatal diarrheic dairy calves in Spain

Faeces samples from 218, one to 30 days old, diarrheic dairy calves in 65 dairy herds were screened for the presence of rotavirus and concurrent infections with coronavirus, Cryptosporidium, F5 + Escherichia coli and Salmonella spp. Calves were grouped according to their age as follows: 1–7, 8–14, 15–21 and 22–30 days. Rotavirus infection was detected in 46.9%, 45.6%, 33.8% and 48.3% of the calves in the respective age-groups. No significant differences in the detection rate of rotavirus were found among calves on the different age-groups. Rotavirus was the only enteropathogen detected in 39 of the 93 (41.9%) diarrheic calves positive to this agent. Concurrent infections with other enteropathogen(s) were detected in 31.3%, 33.3%, 20.6% and 3.4% of the rotavirus infected calves in the age-groups 1–7, 8–14, 15–21 and 22–30 d, respectively. A significant age-associated decrease in the detection rate of mixed infections ( p<0.01) was found. The detection rates of the other enteropathogens considered in calves with rotavirus infection were 20.4% for coronavirus, 85.2% for Cryptosporidium, 16.7% for F5 + E. coli and 1.8% for Salmonella.

A study of the aetiological agents of childhood diarrhoea in Lagos, Nigeria

From December 1989 to May 1990, 315 faecal samples from children under 5 years old with diarrhoea (215) and without diarrhoea (100) seen at paediatric clinics were investigated for bacterial, viral and parasitic enteropathogens. Standard and recently described methods were used for the investigations, which revealed that 74.9% of children with diarrhoea were infected with enteropathogens compared with 28% of controls. In the diarrhoeal group, 59.1% had a bacterial, 26.5% a viral and 2.3% a parasitic aetiology. Rotavirus was the pathogen most frequently detected, accounting for 22.3% of positive findings in the group with diarrhoea versus 9% in the control group. Other important agents were: enterotoxigenic Escherichia coli (ETEC) (14.4 versus 6%), enteropathogenic E. coli (EPEC) (10.7 versus 5%), enteroadherent E. coli (EAEC) (9.3 versus 4%), enterohaemorrhagic E. coli (EHEC) (5.1 versus 3%) and Salmonella spp. (3.3 versus 1%). The following enteropathogens were detected exclusively in the diarrhoeal stools: Shigella spp. (5.1%), Yersinia enterocolitica (0.9%), Aeromonas hydrophila (1.4%), Entamoeba histolytica (0.5%), Giardia lamblia (0.5%), Trichomonas hominis (0.5) and Trichuris trichiura (0.9%). The detection rates of rotavirus, EPEC and EAEC were much greater in the diarrhoeal than in the control patients. No Vibrio cholerae, enteroinvasive E. coli (EIEC), Plesiomonas spp. or Cryptosporidium spp. were detected in this study. Our data suggest that both the traditional and newly recognised diarrhoeal agents are important causes of diarrhoea in the children under 5 years old in Lagos, Nigeria.

Rotavirus diarrhea in Jewish and Bedouin children in the Negev region of Israel

We conducted a 1-year prospective study in the Negev region of southern Israel to determine the epidemiologic and clinical patterns of rotavirus diarrhea. A total of 605 patients were studied, 392 Bedouins and 213 Jews, 441 of whom had diarrhea (449 episodes) and 164 did not. Rotavirus was the most common organism detected in children with diarrhea (63 of 444; 14%) but was rarely found in controls (3 of 163; 2%) (P less than 0.001). In 22% (12 of 54) of the rotavirus-positive patients, at least one other organism was also detected. The rate of rotavirus detection decreased as age increased, from 18% in the first year to 8% in the third year of life. Hospitalization with rotavirus diarrhea occurred more frequently in the summer. However, during winter, when diarrhea was less prevalent in the community, the proportion of cases associated with rotavirus was higher. Compared with controls, malnourished children were more likely to be hospitalized. However, rotavirus was detected in similar proportions among well-nourished and malnourished cases with diarrhea. The most prevalent rotavirus serotype was type 1 (in 69%), followed by types 4 and 2 (18 and 13%, respectively). We estimated that during the study period, approximately 2% of all Bedouin infants vs. only 0.2% of Jewish infants were hospitalized with rotavirus disease in their first year of life. Clinical signs and symptoms and stool appearance were not useful in predicting rotavirus detection. Malnutrition seems to be an important indicator of disease severity, which may explain why the toll of rotavirus-associated morbidity and mortality is particularly high among children in developing countries.

Influence of humidity on rotavirus prevalence among Nigerian infants and young children with gastroenteritis.

Rotaviruses were detected by counterimmunoelectro-osmophoresis in the feces of 16 (13.8%) of 116 infants and young children with gastroenteritis during a 5-month period (September 1979 through January 1980) in Ife, Nigeria. The rate of rotavirus detection varied inversely with relative humidity and was highest in December (38.5% positive) when the humidity was lower. There was not such a distinct relationship with temperature or vapor pressure; and although the rate of rotavirus detection was higher in the drier months (November to January; 19.3% positive) than in the rainy season months (September and October; 8.5% positive), the average humidity was lower in the drier months than in the rainy months. Low relative humidity (49 to 78%) is apparently the most important environmental factor for rotavirus survival and spread in this area.