Molecular epidemiology of rotavirus diarrhea among children and adults in Nepal: detection of G12 strains with P[6] or P[8] and a G11P[25] strain

In anticipation of a rotavirus vaccine in Nepal, this study was undertaken to determine the distribution of the G and P serotypes and electropherotypes of rotaviruses in order to examine if there is any emerging serotype or unusual strain circulating in children and adults in Nepal. Of 1,315 diarrheal stool specimens, rotavirus was detected by an enzyme-linked immunosorbent assay in 116 (17%) of 666 patients less than 5 years of age, in 18 (7%) of 260 patients 5 to 14 years of age, and in 19 (5%) of 358 patients 15 years of age and older. Approximately 75% of rotavirus diarrhea occurred in children less than 5 years of age. Approximately 70% of rotaviruses found in each of the three age groups belonged to serotype G1P[8]. Interestingly, there were 29 (20%) G12 rotaviruses carrying either P[8] or P[6] and one (0.7%) G11 rotavirus carrying an unusual P[25] genotype. RNA polyacrylamide gel electrophoresis discriminated 19 strains (electropherotypes), among which there were three codominant strains carrying G1P[8] and long RNA patterns. Five electropherotypes were discriminated among G12 rotaviruses, all of which had long RNA patterns. The fact that 20% of rotaviruses were G12 strains carrying either P[8] or P[6] and had multiple electropherotypes suggest that G12 strains are not more rare strains but that they pose an emerging challenge to current and future vaccines. The presence of multiple strains as defined by electropherotypes suggests the richness of the rotavirus gene pool in Nepal, where unusual strains may continue to emerge.     

Culture adaptation and characterization of group A rotaviruses causing diarrheal illnesses in Bangladesh from 1985 to 1986.

Group A rotaviruses collected between 1985 and 1986 during comprehensive surveillance of treated diarrheal episodes occurring in a rural Bangladesh population were culture adapted and characterized by electropherotype, serotype, and subgroup. Of 454 episodes of rotavirus-associated diarrhea, rotaviruses were culture adapted from 381 (84%), and 335 contained 11 electrophoretically identical segments in unpassaged and cultured preparations. These 335 comprised 69 different electropherotypes with between 1 (32 isolates) and 79 representatives. The persistence of specific rotavirus strains within the study population, as defined by the detection of viruses with particular electropherotypes, was generally limited to a period of only a few months. All 335 isolates were serotyped by neutralization with hyperimmune antisera to prototype rotavirus strains representative of serotypes 1 to 4, i.e., Wa, DS-1, P, and ST-3. It was found that 80, 48, 119, and 88 isolates belonged to serotypes 1 to 4, respectively. The concentrations of hyperimmune antisera required to neutralize these isolates, however, were at least threefold greater than those needed to neutralize the homologous strains. Therefore, the isolates appeared to have altered neutralization epitopes from their prototype strains. Furthermore, the serotype 4 isolates were consistently shown to be much more closely related to the serotype 4B VA70 strain than the serotype 4A ST-3 strain. All but two isolates identified as serotypes 1, 3, or 4 had long electropherotypes and were subgroup II, and all but one serotype 2 isolate were subgroup I and had short electropherotypes. The three disparate strains appeared to be genetic reassortants. Evidence is presented that dual infections required for reassortant formation were not uncommon. Thus, formation of multiple reassortants may have been a cause for the observed rapid shift in viral strains within the study population.     

Heterogeneity of VP4 neutralization epitopes among serotype P1A human rotavirus strains.

We have used serotype-specific VP4 and VP7 neutralizing monoclonal antibodies (Nt-MAbs), as well as subgroup (SG)-specific MAbs, to characterize by enzyme immunoassay rotavirus strains isolated from diarrheic infants in the city of Monterrey, Mexico, from July 1993 to March 1994. Of a total of 465 children studied, 140 were rotavirus positive, including 3 patients infected with non-group A rotaviruses. The SG and VP7 (G) serotype specificities could be determined for 118 (84%) of the 140 rotavirus-positive stool specimens; 4 rotavirus strains were serotype G1 and SGII; 1 strain was serotype G2 and SGI+II; 112 strains were serotype G3 and SGII; 1 strain was serotype G3 and SGI; and none of the strains was serotype G4. Fifty-eight specimens, representing the 13 different group A rotavirus electropherotypes detected, were chosen for VP4 (P) serotyping. Of these, 48 (83%) strains reacted with the P1A serotype-specific Nt-MAb 1A10. None of the strains reacted with the serotype P2-specific Nt-MAbs tested. Not all viruses that reacted with Nt-MAb 1A10 were recognized by Nt-MAbs 2A3 and 2G1, which also recognize P1A strains, indicating heterogeneity of neutralization epitopes among serotype P1A human rotaviruses. This heterogeneity could be relevant for the specificity of the VP4-mediated neutralizing antibody immune response and indicates the need for antigenic characterization, in addition to genomic typing, of the VP4 proteins of circulating human rotavirus field strains.     

Antigenic characterization of rotaviruses isolated in Kenya from 1982 to 1983.

The electropherotypes of human rotavirus RNAs from 100 diarrheic stool specimens collected in two major districts of Kenya from 1982 to 1983 were previously reported (Y. Chiba, C. Miyazaki, Y. Makino, L. N. Mutanda, A. Kibue, E. O. Lichenga, and P. M. Tukei, J. Clin. Microbiol. 19:579-582, 1984). Of these specimens, 25 that contained rotaviruses with different RNA electropherotypes were subjected to a virus isolation experiment with MA-104 cells, and 16 rotavirus strains were isolated. The use of an enzyme-linked immunosorbent assay with subgroup-specific monoclonal antibodies enabled us to successfully subgroup 15 isolates: 4 in subgroup I and 11 in subgroup II. By fluorescent-focus-neutralization test with serotype-specific rabbit antisera, 13 isolates could be serotyped: 7 as serotype 1, 4 as serotype 2, and 2 as serotype 3. Of the remaining three isolates, F153, F247, and G402, the former was doubly neutralizable with serotype 1 and serotype 4 antisera and the latter two were neutralizable with serotype 3 and serotype 4 antisera. Detailed analysis with the antisera against F153 and F247 and four serotype-specific, VP7-directed monoclonal antibodies suggested that F153 is a serotypic mosaic strain with serotype 4-specific VP3 and serotype 1-specific VP7 outer capsid proteins and F247 and G402 are possibly antigenic mosaic strains with serotype 3 and serotype 4 antigens. On the basis of the correspondence of the rotavirus isolate serotypes determined in this study to the electropherotypes reported previously, it was inferred that serotype 1 strains were most prevalent in two districts of Kenya from 1982 to 1983, followed by any type of serotypic mosaic strains.     

Rotavirus serotypes and electropherotypes in Finland from 1986 to 1990

Summary Four epidemic seasons of rotaviruses were studied in Helsinki during 1986–1990. This is the first Scandinavian study, where both electropherotypes and serotypes are determined. Out of 5316 fecal specimens 769 (14.5%) rotavirus positive samples were detected by electron microscopy. Of these, 645 isolates (83.9%) gave a clear RNA pattern in gel electrophoresis and they clustered into 87 electropherotypes. An illustrative number of isolates representing each electropherotype (=E-type) was serotyped using VP7 protein-specific monoclonal antibodies for serotypes G1–G4 and without exceptions, within one E-type only a single serotype specificity was found. After establishment of the serotype of each E-type, the distribution of serotypes was scored as 61.2%, 2.0%, 0.5% and 29.8% for G1–G4, respectively; 6.5% remained untypable. Two seasons had one predominant E-type (Season 1, 1986–87, and Season 3, 1988–89, 84.2% and 80.6% of rotavirus positive samples, respectively). Both were followed by a season with no predominant E-type, but several minor E-types. Altogether, 5 short E-types (13/645 samples) with serotype G2 specificity were found, most of them occurring in Season 2. Only 2 E-types (3 samples) belonged to serotype G3. Group C rotavirus was found in 8 specimens. In this study a shift in serotypes, from G1 to G4, was observed in Finland in 1988/89; a similar shift was reported in many European countries at that time.     

Anticipating rotavirus vaccines in Brazil: detection and molecular characterization of emerging rotavirus serotypes G8 and G9 among children with diarrhoea in Recife, Brazil

In 2006, Brazil will initiate universal immunization of its 4-million infants with a live attenuated serotype G1P[8] human rotavirus vaccine. In anticipation of the national immunization program, this study was undertaken to characterize rotavirus strains circulating among children in Recife, one of the largest cities in the northeast region of Brazil. Group A rotaviruses were detected in 102 (35%) of 290 faecal specimens collected from children under 5 years of age who presented with acute diarrhoea during a 1-year period between May 2004 and April 2005. In addition to the globally common G1P[8] serotype that accounted for 49% of strains, emerging rotavirus serotypes G8P[6] and G9P[8] represented 2% and 29% of strains, respectively. Following cell culture adaptation, RNA-RNA hybridization demonstrated that two Brazilian G8P[6] rotavirus strains shared a high level of genomic RNA homology with Malawian G8P[6] strains, and a Brazilian G9P[8] strain was related most closely to a G9P[8] strain from India. The results suggest that certain rotavirus strains have a much wider global circulation than generally appreciated. Continued global spread of such strains might challenge the efficacy of current rotavirus vaccines.     

Characterization of neutralization specificities of outer capsid spike protein VP4 of selected murine,lapine, and human rotavirus strains

Neutralization specificities of outer capsid spike protein VP4 of murine rotavirus strains EW (P?[16],G3) and EHP (P?[20],G3) and lapine rotavirus strains Ala (P?[14],G3), C11 (P?[14],G3), and R2 (P?[14],G3) as well as human rotavirus strains PA169 (P?[14],G6) and HAL1166 (P?[14],G8) were determined by two-way cross-neutralization. This was done by generating and characterizing (i) three murine x human, three lapine x human, and two human x human single gene substitution reassortant rotaviruses, each of which bore identical human rotavirus DS-1 strain VP7 (G2), and (ii) guinea pig hyperimmune antiserum raised against each reassortant. Reference rotavirus strains employed in the study represented 10 established VP4 (P) serotypes, including 1A[8], 1B[4], 2A[6], 3[9], 4[10], 5A[2], 5B[2], 5B[3], 6[1], 7[5], 8[11], 9[7], and 10[16] as well as a P serotype unknown P[18]. Murine rotavirus strains EW and EB were demonstrated to share the same P serotype (P10[16]) distinct from (i) 9 established P serotypes, (ii) lapine and human rotavirus strains bearing the P[14] genotype, and (iii) an equine rotavirus strain bearing the P[18] genotype. Both lapine (Ala, C11, and R2) and human (PA169 and HAL1166) rotaviruses were shown to belong to the same VP4 serotype, which represented a distinct new P serotype (P11[14]). P serotype 13[20] was assigned to murine rotavirus EHP strain VP4, which was shown to be distinct from all the P serotypes/genotypes examined in the present study.     

Electropherotypes and serotypes of human rotavirus in Estonia in 1989–1992

Summary The electropherotypes and serotypes of human rotaviruses circulating in Tallinn (Estonia) in 1989–1992 have been studied. Rotaviruses were found in 372 (25.8%) of 1 442 faecal specimens of pediatric patients with acute diarrhea. Polyacrylamide gel electrophoresis of RNA from 318 isolates has revealed 41 electropherotypes. Frequent genomic alterations, including a shift of predominant electropherotypes, were observed during the study period. The serotype of 158 (50.3%) of 314 tested rotavirus isolates was identified using ELISA with VP7-specific monoclonal antibodies against 4 established human rotavirus serotypes. Serotype G1 was found to be largely predominant and accounted for 70.9% of the typeable specimens, serotypes G4, G2, and G3 accounted for 12%, 9.5%, 7.6%, respectively. A major shift to serotype G4 took place in 1990–1991. Serotype G1 was represented by the largest number of electropherotypes. All G1, G3 and G4 isolates were of long and all G2 isolates were of short electropherotypes. According to our results the isolates of an identical electropherotype belong to the same serotype.     

Sequence analysis of VP4 and VP7 genes of nontypeable strains identifies a new pair of outer capsid proteins representing novel P and G genotypes in bovine rotaviruses

During a limited epidemiological study, the serotype specificities of several isolates of bovine rotavirus, exhibiting identical electropherotypes, from a single cattle farm near Bangalore, India, could not be determined using a panel of serotyping monoclonal antibodies (MAbs) specific for G serotypes 1-6 and 10. To determine the genotypes of these isolates, the nucleotide sequences of the genes encoding the outer capsid proteins VP4 and VP7 of two representative isolates, Hg18 and Hg23, were determined. The corresponding gene sequences from the two isolates were identical, indicating that these isolates represented a single strain of bovine rotavirus. Comparison of the VP4 nucleotide (nt) and the deduced amino acid (aa) sequences with those of several human and animal rotavirus strains representing all of the currently recognized 20 different VP4 (P) genotypes revealed low nt and aa sequence identities of 61.0 to 74.2% and 57.9 to 78.2% for VP4. The percentages of amino acid homology for the VP8* and VP5* regions of VP4 were 37.7 to 67.9 and 68.1 to 84.2%, respectively. The nt and aa sequences of the VP7 gene were also distinct from those of human and animal strains belonging to the previously established 14 VP7(G) serotypes (65.9 to 75.5% nt and 59.5 to 77.6% aa identities). These findings suggest the classification of the VP4 and VP7 genes of the bovine isolates represented by Hg18 as new P and G genotypes and provide further evidence for the vast genetic/antigenic diversity of group A rotaviruses.     

Diversity in Indian equine rotaviruses: identification of genotype G10,P6[1] and G1 strains and a new VP7 genotype (G16) strain in specimens from diarrheic foals in India

Rotaviruses causing severe diarrhea in foals in two organized farms in northern India, during the period from 2003 to 2005, were characterized by electropherotyping, serotyping, and sequence analysis of the genes encoding the outer capsid proteins. Of 137 specimens, 47 (34.31%) were positive for rotavirus and exhibited at least five different electropherotypes (E), E1 to E5. Strains belonging to different electropherotypes exhibited either a different serotype/genotype specificity or a lack of reactivity to typing monoclonal antibodies (MAbs) used in this study. Strains belonging to E1, E2, and E5 exhibited genotype G10,P6[1], G3, and G1 specificities and accounted for 19.0, 42.9, and 9.5% of the isolates, respectively. Though they possessed G10-type VP7, the E1 strains exhibited high reactivity with the G6-specific MAb, suggesting that the uncommon combination of the outer capsid proteins altered the specificity of the conformation-dependent antigenic epitopes on VP7. E3 and E4 strains accounted for 28.6% of the isolates and were untypeable. Sequence analysis of VP7 from E4 strains (Erv92 and Erv99) revealed that they represent a new VP7 genotype, G16. The detection of unexpected bovine rotavirus-derived G10,P6[1] reassortants, G1 serotype strains, and a new genotype (G16) strain in two distant farms reveals an interesting epidemiological situation and diversity of equine rotaviruses in India.     

Molecular epidemiologic analysis of group A rotaviruses in adults and children with diarrhea in Wuhan city,China, 2000–2006

Summary To compare epidemiologic features and genetic characteristics of group A rotaviruses causing diarrhea in children and adults, a survey was conducted in Wuhan, China, during the period of Dec. 2000–May 2006. A total of 3839 stool specimens from diarrheal patients from eight hospitals were analyzed. Winter seasonality was observed for rotavirus diarrhea in both adults and children, showing overall rotavirus-positive rates of 9.0 and 23.9%, respectively. Throughout the study period, G3 was the most frequent G serotype in both adults and children (detection rates 86.2 and 87.8%, respectively), and was mostly associated with VP4 genotype P[8], VP 6 genotype II (subgroup II), and NSP4 genotype B. G3 rotaviruses were differentiated into eight electropherotypes, among which seven types were found in specimens from both adults and children. VP7 gene sequences of G3 rotaviruses from adults and children (6 and 4 strains, respectively), detected in different years and different hospitals, showed extremely high sequence identities (99–100%) to each other and to a few G3 rotavirus strains reported in Asia. However, lower sequence identities (82–96%) were observed to most of the human and animal G3 rotaviruses reported so far, including some Chinese strains. These findings indicate that in Wuhan, China, epidemic and genetic features of rotaviruses are similar in adults and children, and it has been suggested that G3 rotaviruses that might have originated from the same rotavirus were circulating among children and adults as prevailing viruses. In this study, two rotavirus strains, G9P[8] strain L169, derived from an adult, and G4P[6] strain R479, derived from a child, were isolated and genetically analyzed. The VP7 gene of L169 belongs to a major lineage of G9 rotaviruses that are globally widespread, but is distinct from G9 rotaviruses reported previously in China. The strain R479 had a VP7 gene which was divergent from most G4 human rotaviruses and showed an unusual dual subgroup specificity, I + II. The R479 VP6 gene does not belong to the main clusters of subgroup I and II rotaviruses phylogenetically, but is related to those of the porcine rotaviruses and some unusual human rotaviruses represented by the RMC321 strain isolated in eastern India.     

Diversity of human rotavirus G9 among children in Turkey

Between September 2004 and December 2005 a prospective study was conducted to understand the epidemiology of rotavirus infection among children with diarrhea attending two hospitals in Ankara, Turkey. Rotavirus was detected in 39.7% of the 322 stool samples and affected mainly children in the age group of 6-23 months. More than 70% and 39% of these cases occurred in children <2 and <1 year of age, respectively. In the temperate climate of Ankara rotavirus infection was prevalent throughout the year. Serotype G1P[8] was dominant followed by G9P[8]. In 38 samples a total of 5 electropherotypes were detected. All G9P[8] were of long electropherotype except one of short electropherotype. A proportion of G1 and G9 strains were in combination with P[6], P[4] or P nontypable. Mixed serotypes were responsible for 2.4% of the infections. A phylogenetic tree constructed with the deduced amino acid sequences of the VP7 gene showed that 16 Turkish G9 strains clustered with rotaviruses of lineage III. One G9 strain formed a new lineage, lineage IV with the Sri Lankan G9 rotaviruses. In the phylogenetic tree of the VP8* gene, the Turkish G9P[6] rotaviruses clustered with human strains of lineage Ia. Increased diversity of the G/P type combination and the presence of infection throughout the year in Turkey was a situation similar to developing countries. The occurrence of rotavirus infection at later age and low level of mixed infections in Turkey represented the situation of developed countries. This study suggests that diverse G9 rotaviruses are emerging in Turkey.     

Epidemiological study of the G serotype distribution of group A rotaviruses in Kenya from 1991 to 1994.

An epidemiological study on the G serotype distribution of group A rotaviruses (GARV) isolated in Kenya was carried out in one urban hospital in Nairobi and in two rural hospitals in Nanyuki and Kitui to clarify the prevalent G serotypes before future introduction of the ready licensed rotavirus vaccine in Kenya. A total of 1,431 stool specimens were collected from children, who were mainly outpatients, aged from 0 to 6 years old with acute gastroenteritis from August 1991 to July 1994. Samples positive for GARV by conventional ELISA were then analyzed by subgrouping and serotyping ELISA and by PAGE. To ascertain the G serotypes of viruses in samples that were unable to be typed by serotyping ELISA, polymerase chain reaction was also attempted. The prevalence of GARV was 28.4% in the urban hospital, 22.5% in Nanyuki, and 13.7% in Kitui. Among rotavirus-positive samples, subgroup II rotaviruses were detected in 63.1%, and subgroup I rotaviruses were 25.9%. Serotype G4 was most prevalent, accounting for 41.6% followed by 23.3% of serotype G1, 17.0% of serotype G2, and serotype G3 was rarely isolated. Seven strains of serotype G8/P1B rotavirus was detected for the first time in Kenya by RT-PCR. Eleven specimens with an unusual composition of subgroup, serotype, and electropherotype were atypical GARV in which the P-serotype was P1A, P1B, or P2. Although uncommon GARV serotype G8/P1B and atypical GARV were detected, the four major GARV serotypes, G1 through G4, should be targeted at this moment for vaccination to control this diarrheal disease in Kenya. Continuous monitoring of the G- and P-serotype distribution of GARV should provide important information about the impact of rotavirus vaccination in Kenya.     

Genetic relatedness among human rotavirus genes coding for VP7, a major neutralization protein, and its application to serotype identification.

Antigenic characterization of human rotaviruses by plaque reduction neutralization assay has revealed four distinct serotypes. The outer capsid protein VP7, coded for by gene 8 or 9, is a major neutralization protein; however, studies of rotaviruses derived from genetic reassortment between two strains have confirmed that another outer capsid protein, VP3, is in some cases equally important in neutralization. In this study, the genetic relatedness of the genes coding for VP7 of human rotaviruses belonging to serotypes 1 through 4 was examined by hybridization of their denatured double-stranded genomic RNAs to labeled single-stranded mRNA probes derived from human-animal rotavirus reassortants containing only the VP7 gene of their human rotavirus parent. A high degree of homology was demonstrated between the VP7 genes of strain D and other serotype 1 human rotaviruses, strain DS-1 and other serotype 2 human rotaviruses, strain P and other serotype 3 human rotaviruses, and strain ST3 and other serotype 4 human rotaviruses. Hybrid bands could not be demonstrated between the VP7 gene of D, DS-1, P, or ST3 and the corresponding gene of human rotaviruses belonging to a different serotype. RNA specimens extracted from the stools of 15 Venezuelan children hospitalized with rotavirus diarrhea were hybridized to each of the reassortant probes representing the four human serotypes. All five viruses with short RNA patterns showed homology with the DS-1 strain VP7 gene; two of these were previously adapted to tissue culture and shown to be serotype 2 strains by tissue culture neutralization. Of the remaining 10 viruses with long RNA patterns, 2 hybridized only to the D strain VP7 gene, 6 hybridized only to the P strain VP7 gene, and 2 hybridized only to the ST3 strain VP7 gene. Hybridization using single human rotavirus gene substitution reassortants as probes may provide an alternative method for identifying the VP7 serotype of field isolates that would circumvent the need for tissue culture adaptation.     

Antigenic and genetic characterization of serotype G2 human rotavirus strains from South Africa from 1984 to 1998

Within South Africa, cyclic peaks of serotype G2P[4] rotavirus infection have been observed and these strains were prevalent in some locations. To examine the cyclic phenomenon of serotype G2 rotaviruses, historical stool collections from South Africa spanning 15 years were screened for G2 strains. Subgroup (VP6) ELISA, polyacrylamide gel electrophoresis (PAGE), and P genotyping were performed on 43 G2 strains to investigate the associated DS-1 genogroup characteristics. Antigenic variation of the gene encoding the major neutralization glycoprotein (VP7) was also investigated using G2-specific monoclonal antibodies. In addition, the VP7 gene of 14 serotype G2 strains was sequenced to examine genetic variation. Serotype G2 strains from South Africa displayed a 10 year cyclic pattern with major epidemics occurring in 1987 and 1997. Serotype G2 strains were also found co-dominant with G(1) strains in 1984, 1990, and 1993. The G2 strains from the major epidemics appeared to have emerged from community strains in a manner similar to that suggested for G(1) strains The serotype G2 strains displayed subgroup I specificity and short electropherotypes characteristic of DS-1 genogroup rotavirus strains but appeared to differ in the VP4 gene. Genetic analyses revealed three major serotype G2 lineages, i.e., strains isolated prior to 1987, strains isolated between 1988 and 1994, and strains isolated from 1995. The use of monoclonal antibodies and PCR primers designed against older G2 strains has resulted in the failure to serotype G2 strains circulating currently.     

Characterization of unusual G8 rotavirus strains isolated from Egyptian children

Summary.  We report the first detection of P[14], G8 rotaviruses isolated in Egypt from the stool of children participating in a 3 year study of rotavirus epidemiology. Two strains, EGY1850 and EGY2295, were characterized by a serotyping enzyme immunoassay (EIA), virus neutralization, and sequence analysis of the genes encoding VP7 and the VP8^* portion of the VP4 gene. These two strains shared a high level of homology of their VP7s (87.8% nucleotide [nt], 97.2% amino acid [aa]) and VP4s (89.6% nt, 97.1% aa) and had the highest VP7 identity to serotype G8 (>82% nt, >92% aa) and VP4 identity to genotype P[14] (≥81% nt, >91% aa) strains. Serological results with a VP7 G8-specific and VP4 P[14]-specific neutralizing monoclonal antibodies supported the genetic classification of EGY1850 and EGY2295 as P[14], G8. Genogroup analysis supports earlier findings that human G8 rotaviruses may be genetically related to bovine rotaviruses. These findings demonstrate that our understanding of the geographic distribution of rotavirus strains is incomplete, emphasize the need to monitor rota- virus serotypes, and extend the known distribution of serotype G8 and genotype P[14] strains in Africa. Received Nvember 3, 1998 Accepted February 14, 1999     

Clinical manifestations of the rotavirus infection and his relation with the electropherotypes and serotypes detected during 1998 and 1999 in Merida, Yucatan, Mexico.

BACKGROUND: Group A rotavirus (RV) is associated with acute infectious diarrhea (AID) in children and adults. The clinical manifestations of RV infection are classified as slight, moderate and severe and could be the results of differing rotaviral serotypes. Attempts have been made to correlate the severity of the infection with specific RV groups, subgroups (SG) serotypes and electropherotypes, but the results have been inconclusive. OBJECTIVE: To correlate the severity of the RV infection with the strains of RV isolated from the patients. STUDY DESIGN: 142 feces were collected from patients with AID caused by RV. The samples were subjected to polyacrylamide gel electrophoresis (PAGE) to determine the electrophoretic pattern and immunoenzymatic assays with monoclonal antibodies specific for serotype, SG and group. The Program EPIINFO 6.0 was used to analyze the correlation. RESULTS: The 142 RV strains isolated were from group A and long electrophoretic pattern. Respect to the symptoms were classified, 43 (30%) as slight; the RV isolates corresponding to these patients were 35 of serotype G1P1A SG II; 4 G1P1A SG I and II; 1 G1P1A SG Non I Non I; 1 G3 SG II; 1 G3 SG Non I and Non II and 1 G3 SG I and II. 89 (53%) of patients showed moderate clinical symptoms. 58 isolates of RV were G1P1A SG II; 11 G1P1A SG Non I Non II; 9 G1P1A SG I and II; 1 G1P1B SG II; 1 G4P1A SG II; 1G1 and G4 SG I and II; 6 G3 SG Non I Non II; 2 G3 SG II. The severe RV infection occurred in only 10 (7%). 8 were serotype G1P1A SG II and 2 were G1P1A SG I and II. CONCLUSION: This study demonstrated that the severity of AID has no significant statistical relationship to the specific RV strains isolated from the patients.