Seroepidemiology of enteric fever and brucellosis in a developing country

The seroepidemiology of infection due to S. typhi and Brucella spp. in a sub-tropical, developing country of the Middle East was investigated in 130 children of age less than 1 to 15 years, 117 young adults (16-30 years) and in a further 40 adults (greater than 30 years) using an agglutination test to detect antibodies to of S. typhi, B. abortus and B. melitensis. Only 4.5% of the children's and adult's sera respectively showed the presence of antibodies to both O and H antigens of S. typhi with reciprocal titers greater than or equal to 80. Prevalence rates of 11.6%, 11.3% respectively in children and adults of antibodies to B. abortus with reciprocal titers greater than or equal to 80 and similarly 13.1%, 12.4% to B. melitensis were found. The usefulness of a single Widal test to diagnose enteric fever in a non-endemic area and the agglutination test in the diagnosis of brucellosis in an endemic area was investigated. Of 244 patients with suspected enteric fever, the sera of 100 showed reciprocal antibody titers 80 to both O and H antigens and included in these were 8 patients with concurrent culture positivity. Among 138 children and adults with suspected brucellosis, 29 culture proven cases where serologically confirmed and a further 90 were detected serologically. The sera of all the culture proven cases exhibited antibody reciprocal titer greater than or equal to 640. A similar antibody response was noted in seventy-two of the culture negative cases diagnosed serologically for brucellosis. In culture proven, cases B. melitensis was the isolate. Comparative evaluation indicated the potential usefulness of the Rose Bengal Antigen Slide Agglutination Test (Brucelloside Test) as a screening test in the serodiagnosis of human brucellosis.     

The prevalence of helicobacteriosis in regions of Siberia based on serological study data

687 adults in 5 regions of Siberia and 79 children and young persons in Novosibirsk were examined. IgG antibodies to H. pylori in their blood sera were determined with the use the enzyme immunoassay. The detection rate of antibodies among the adult population varied within 70-87%, depending on the region, being somewhat lower among the population north of latitude 60 degrees (75%) in comparison with the population residing south of this latitude (86%, p < 0.001). In Novosibirsk the number of seropositive persons was found to be unrelated to sex, age and clinical manifestations of digestive tract diseases. A high detection rate of antibodies to H. pylori was registered in persons aged 25-34 years with a minor increase in older age groups. In children the detection rate increased with age: 29% in children of 5-10 years old and 56% in children 11-14 years old. By the age of 15 more than a half of the children had antibodies.     

The HIV infection epidemic in the city of Irkutsk under the conditions of drug abuse prevalence

The data on the spread of HIV infection in Irkutsk and Irkutsk Province, starting from March 9, 1999, are presented. The simultaneous appearance of 17 multiple morbidity foci of HIV infection, involving 2,227 persons into the epidemic, within the period of 8 months was noted. The age structure of the epidemic process was represented by 1,846 adults aged 18-50 years (83%), 256 adolescents aged 16-17 years (12.9%), 78 children aged 10-15 years (3.5%) and 17 persons of other ages (0.53%). The leading role in the age structure of the epidemic process belonged to young people aged 10-29 years (90.4% of cases). The epidemiological analysis made it possible to establish the fact that the epidemic was linked with the intravenous injection of heroin. The viral contamination of the drug is not excluded also in the process of its preparation for injection.     

Certain data concerning the analysis of the foci of infectious hepatitis in cases of subsequent occurrence of the disease in families

Materials of epidemiological analysis of familial infectious hepatitis nidality in 104 families are presented. The data obtained pointed to the preponderant affection of children constituting 97.1% of primary and 87.7% of subsequent cases in familial foci. Infection was brought to the families by schoolchildren in 57.7% of the cases, and by organized preschoolchildren--in 31.7% of the cases. The greatest affection of schoolchildren aged from 7 to 14 years in the foci with subsequent occurrence of the disease (77.7%) was explained by their marked age activity. This led to the conclusion that mass prophylaxis with alpha-globulin of these particular groups of children was of primary importance. The differences of the specific ratio of adults who contracted the disease in familial foci and in the region as a whole pointed to the possibility of infection of adults outside the family and on the prevalence in them of serum hepatitis.     

Immune structure of the population in some regions of the USSR with respect to Legionella pneumophila

For the first time in the USSR the structure of the immunity of different population groups to L. pneumophila was studied. Antibodies to L. pneumophila were detected in the passive hemagglutination test with the use of erythrocyte diagnosticum prepared at the Gamaleya Research Institute of Epidemiology and Microbiology (Moscow). The survey covered the total number of 2,902 persons in differ nt regions of the USSR, among them 2,430 adults and 472 children. Among the healthy adult population antibodies to L. pneumophila were detected, on the average, in 5.9% of persons. The highest number of persons with antibodies in diagnostic titers was detected among the population of the Baltic Republics (15.9%) and Kazakhstan (10.2%). The survey revealed an essential difference in the number of children aged 3-7 years, found to have antibodies to L. pneumophila, in the Brest region of the Byelorussian SSR (31.4%) and in the Turkmen SSR (1.3%). The high risk groups exposed to L. pneumophila infection were found to include narcological patients with the changed reactivity of the body and healthy adults professionally employed in earth-moving works.     

Characteristics of brucellosis epidemiology in children in the Kazakh SSR

The analysis of brucellosis morbidity among children in the Kazakh SSR for the last 10 years revealed the following facts. The highest morbidity rate among children was registered in zones with developed sheep breeding. Privately owned agricultural animals, mainly small cattle, proved to be the main source of infection, transferred in most cases through contacts. contacts. The occurrence of brucellosis among children was found to be directly related to their age. Most of the sick children were boys. The pronounced seasonal character of brucellosis morbidity, falling mainly on spring and summer, was observed. In surveying the population for brucellosis the use of a complex of sero-allergic tests permitted the detection of a great number of infected subjects. Most sick children showed a typical picture of acute brucellosis. Treatment resulted in their clinical convalescence.,     

A trial of using immunoglobulins of known specificity for preventing hepatitis A in regions with high epidemic activity

The economic effectiveness of immunoglobulin prophylaxis (IGP), carried out among children aged 1-3 at the beginning of a seasonal rise in hepatitis A (HA) morbidity with high coefficients of protection (80-85%), was directly related to the activity of the epidemic process. Preparations with sufficiently high content of antibodies to HA virus sharply decreased the manifestation of this infection. The detection rate of the manifest forms of the infection among children covered by prophylactic measures in the foci of HA was considerably lower than among children who had not received the preparation. IGP exerted no essential influence on the dynamics of the formation of population immunity. A high share of children aged 3-4 years, seropositive to HA virus (up to 90%), validates the inadvisability of carrying out IGP in older groups of children.     

Seroprevalence of IgG antibodies against SARS-CoV-2 among the general population and healthcare workers in India,June–July 2021: A population-based cross-sectional study

BackgroundIndia began COVID-19 vaccination in January 2021, initially targeting healthcare and frontline workers. The vaccination strategy was expanded in a phased manner and currently covers all individuals aged 18 years and above. India experienced a severe second wave of COVID-19 during March–June 2021. We conducted a fourth nationwide serosurvey to estimate prevalence of SARS-CoV-2 antibodies in the general population aged ≥6 years and healthcare workers (HCWs).Methods and findingsWe did a cross-sectional study between 14 June and 6 July 2021 in the same 70 districts across 20 states and 1 union territory where 3 previous rounds of serosurveys were conducted. From each district, 10 clusters (villages in rural areas and wards in urban areas) were selected by the probability proportional to population size method. From each district, a minimum of 400 individuals aged ≥6 years from the general population (40 individuals from each cluster) and 100 HCWs from the district public health facilities were included. The serum samples were tested for the presence of IgG antibodies against S1-RBD and nucleocapsid protein of SARS-CoV-2 using chemiluminescence immunoassay. We estimated the weighted and test-adjusted seroprevalence of IgG antibodies against SARS-CoV-2, along with 95% CIs, based on the presence of antibodies to S1-RBD and/or nucleocapsid protein. Of the 28,975 individuals who participated in the survey, 2,892 (10%) were aged 6–9 years, 5,798 (20%) were aged 10–17 years, and 20,285 (70%) were aged ≥18 years; 15,160 (52.3%) participants were female, and 21,794 (75.2%) resided in rural areas. The weighted and test-adjusted prevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein among the general population aged ≥6 years was 67.6% (95% CI 66.4% to 68.7%). Seroprevalence increased with age (p < 0.001) and was not different in rural and urban areas (p = 0.822). Compared to unvaccinated adults (62.3%, 95% CI 60.9% to 63.7%), seroprevalence was significantly higher among individuals who had received 1 vaccine dose (81.0%, 95% CI 79.6% to 82.3%, p < 0.001) and 2 vaccine doses (89.8%, 95% CI 88.4% to 91.1%, p < 0.001). The seroprevalence of IgG antibodies among 7,252 HCWs was 85.2% (95% CI 83.5% to 86.7%). Important limitations of the study include the survey design, which was aimed to estimate seroprevalence at the national level and not at a sub-national level, and the non-participation of 19% of eligible individuals in the survey.ConclusionsNearly two-thirds of individuals aged ≥6 years from the general population and 85% of HCWs had antibodies against SARS-CoV-2 by June–July 2021 in India. As one-third of the population is still seronegative, it is necessary to accelerate the coverage of COVID-19 vaccination among adults and continue adherence to non-pharmaceutical interventions.

Manoj Murhekar and co-workers report on the seroprevalence of anti-SARS-CoV-2 antibodies in India.     

Antidiphtheria and antitetanus antitoxic immunity indices in the population of the Estonian SSR (an assessment of the effectiveness of a planned vaccine prophylaxis)]

In 1972-1974 and 1977 in the Estonian SSR children and adults were surveyed for the presence of antibodies against tetanus and diphtheria toxins (toxoids) by means of the passive hemagglutination test. The level of protection against tetanus was revealed to correspond to the proportion of child population covered by vaccination: in 1977, with 98.8% covered by vaccination, the level of protection among children aged 7 to 14 years and adolescents of 15-19 years exceeded 98%; with the increase of age (every 10-15 years) the level of protection against tetanus regularly decreased. This dynamics correlated with the existing terms of postvaccinal immunity and the epidemiological independence of tetanus as infectiion. The level of protection in child population against diphtheria in 1972-1974 and 1977 lagged behind the level of protection against tetanus and the coverage by vaccination. The diphtheria component of adsorbed DPT vaccine seemed to be unable to ensure the sufficient level and intensity of immunity under conditions of a sharply decreased risk of encounter with the infective agent. In persons aged 40 years and over the indices of immunity against diphtheria were higher than against tetanus. These indices resulted from diphtheria infection at the prevaccination period and could serve as an objective sign in following up the decrease of the process of diphtheria epidemics.     

Synthesis of natural allohemagglutinins of the ABO system in healthy children aged 3 months to 3 years

The work was carried out to establish the titre and score of haemagglutination of natural anti-A and anti-B antibodies in healthy children during the first three years of life. The material studied included 900 healthy children aged between 3 months and 3 years and 100 adults serving as controls. The method of test tube haemagglutination was used for determining the titre and score of alloagglutinins in relation to standard erythrocytes always obtained from the same donors. In addition, in 72 children and 10 adults the levels of IgG, IgA and IgM were determined quantitatively. A statistical analysis of the results showed that the levels of anti-A and anti-B alloagglutinins were relatively high at the age of 3 months / about 25% of the adult levels / and increased very rapidly in the first years of life reaching about 90% of the adult level at the end of the 3rd year of life. Besides that, it was demonstrated that it is useful in clinical practice to use the titre and score of natural alloagglutinins as indicators of humoral immunity, especially in children in the first years of life. Acceleration was demonstrated in the intensity of haemagglutination of natural antibodies in the last 40 years since their titre in the contemporary infantile population / up to the age of 1 year / is about 50% higher than that found in 1929. These findings suggest that increased immune reactivity of children observed presently may be due to prophylactic vaccinations.     

Comparing the Immunogenicity of AS03-Adjuvanted 2009 Pandemic H1N1 Vaccine with Clinical Protection in Priority Risk Groups in England

In England, during pandemic 2009 H1N1, vaccine efficacy and immunogenicity population studies in priority groups were rolled out in parallel to evaluate the pandemic vaccination programme. This provided a unique opportunity to compare immunogenicity and clinical protection in the same population and thus provide insights into the correlates of protection for the pandemic H1N1 2009 vaccine in risk groups. While clinical protection from AS03-adjuvanted pandemic 2009 H1N1 vaccine was high in those aged <25 years and pregnant women, effectiveness in older adults with chronic conditions has been found to be surprisingly poor. Here we present results from the immunogenicity study derived from the same population. Individuals from priority groups eligible for pandemic vaccination attending participating general practices were recruited. Pre and post-vaccination blood samples were collected and HI antibody testing to assess immune response to vaccination performed. The final cohort consisted of 610 individuals: 60 healthy children aged <5 years; 32 healthy pregnant women; 518 individuals from risk groups. Seroconversion rate in healthy children aged <5 years (87%, 95% CI: 75% to 94%) was higher than that of risk groups combined (65%, 95% CI: 61% to 69%) (p<0.001). Multivariable analysis of risk groups showed that the size of response in those who did seroconvert was lower in those who received the 2009/10 seasonal TIV (Fold effect: 0.52, 0.35 to 0.78). Predicted immunological boosting from higher pre-vaccine titres after 2009 pandemic H1N1 vaccination only occurred in children (seroconversion rate = 92%) and not in individuals aged 10 to 39 from risk groups (seroconversion rate = 74%). The lack of clinical protection identified in the same population in older adults from risk groups could be attributed to these lower seroresponses. Current immunogenicity licensing criteria for pandemic influenza vaccine may not correlate with clinical protection in individuals with chronic disease or immunocompromised.     

Data on the study of the epidemiology of rotavirus infection in Leningrad

The results obtained in the study of rotavirus infection in Leningrad in 1984-1987 are presented. Enzyme immunoassay techniques were used for the examination of 4,715 children aged 0-14 years and 1,162 adults with diagnosed acute enteral infection of unknown etiology, as well as the control group of 556 of healthy children aged 0-6 years and 77 healthy adults. The rotavirus antigen was detected in 1.210 sick children (25.7%) and 133 sick adults (11.4%), as well as in 6 healthy children (1.1%), but not detected in healthy adults. The following epidemiological regularities of rotavirus infection were established: the highest sick rate among children aged 0-2 years and a low level of rotavirus carriership among healthy persons; the seasonal character of rotavirus infection, its outbreaks occurring in winter and the epidemic periods varying in their character and duration in different years; the prevailing role of rotaviruses in the development of winter rises of acute enteral infection of unknown etiology in the city among children aged 0-2 years. The problem of the respiratory syndrome in rotavirus diarrhea is discussed. The rotavirus antigen was detected in 39 out of 144 children (27%) with diagnosed acute respiratory virus diseases and in 4 out of 99 nasopharyngeal washings (4%) from diarrhea patients. Adenoviruses were shown to play an insignificant role in the etiology of diarrhea (10% of cases).     

Detection of specific antibodies to morbilliviruses, Toxoplasma, and Brucella species in eared seals in North-West of Pacific Ocean

Presence of antibodies to morbilliviruses, Toxoplasma, and Brucella species in eared seals in North-West of Pacific Ocean was studied. Sera from 189 cubs of eared seals from different rookeries and regions. It has been shown that 10-22% of cubs living on Russian coast have antibodies to such dangerous diseases as morbillivirus infection, brucellosis, and toxoplasmosis. Antibodies to the two pathogens were detected in several animals, and brucellosis was more frequently detected associated infection. These results confirm hypothesis that all 3 pathogens are enzootic in eared seals population.     

The territorial and age-related characteristics of the distribution of patients with non-A, non-B viral hepatitis infected via the fecal-oral mechanism in foci of elevated viral hepatitis morbidity in the Uzbek SSR

The study of patients from 10 foci of acute viral hepatitides for the presence of HBsAg (in the passive reverse hemagglutination test) and anti-hepatitis A virus IgM (in the radioimmunoassay) has shown high frequency and variability in the spread of hepatitis non-A, non-B, the prevalence of adults aged 20-29 years and children aged 2-4 years among persons involved into the epidemic process and the tendency towards an increase in the proportion of hepatitis non-A, non-B in the total number of cases of viral hepatitides in the republic.     

Immunoglobulins and antibodies of various classes in children immunized with live oral Shigella sonnei vaccine from the spontaneous mutant]

The authors determined the immunoglobulin and specific antibodies level in the blood serum of 17 children aged from 7 to 10 years during the immunization with live dysentery Some vaccine. Mancini's test demonstrated the absence of any differences in the amount of IgA and IgG in children of the given age group and in adults before the immunization; in comparison with adults, IgM was increased in children. 14 to 20 days after the immunization in children there was a significant elevation of the IgG only, whereas in adults the immunoglobulin level of all the 3 classes increased significantly. The titres of specific antibodies of the IgA-, IgG-classes and of hemagglutinins before the immunization detected by Coombs' test failed to differ in children from the titres of antibodies of these classes in adults; the level of IgM antibodies was much greater in children than in adults. The changes and accumulation of antibodies of various classes in children and adults during the enteral immunization with live dysentery vaccine differed significantly: in children the vaccine stimulated the IgA- and the IgM-antibody synthesis, whereas adults responded to the immunization by increased production of all the 3 antibody classes. On the basis of the noted immunological shifts a conclusions was drawn on a marked local immunization activity of the live enteral Sonne dysentery vaccine from the spontaneous mutant in children.     

Humoral imunity to pertussis in children with diabetes of type 1

To determine the state of humoral immunity to pertussis in children with insulin-dependent diabetes, IgG antibodies to pertussis toxin (PT) were determined in blood serum samples by means of EIA. In a group of children aged up to 6 years the highest percentage (100%) received the complete course of vaccination against pertussis with Russian adsorbed DPT vaccine, containing whole-cell pertussis monovaccine, while in a group over 6 years the complete vaccination course (3 vaccinations and 1 revaccination) had 53.4% of children. Pertussis morbidity was considerably higher in nonvaccinated subjects than in children with 4-fold vaccination (p < 0.001). The coefficient of association (Q) was 0.84. Children of all age groups were found to have low and average titers of antibodies to PT. The regressive analysis showed a decrease in antibodies in persons completely immunized against pertussis by the age of 6 years old. The presence of antibodies in nonimmunized persons showed that cases of pertussis or carrier state took place among the population. High titers of antibodies, indicative of recent cases of pertussis, were registered in all age groups, but high titers of antibodies were registered mostly in the group of children over 13 years old (p < 0.05), which confirmed an increase in pertussis morbidity in adolescents. Thus, vaccination against pertussis effectively protected children with diabetes of type 1, aged up to 6 years. For more prolonged protection the vaccination and revaccination of children aged over 4 years old is necessary.     

Seroepidemiology of Helicobacter pylori infection in Greece

Abstract Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylrori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.49% of children aged 1–10 years, 67.1% of recruits (20–27 years) and 70% of blood donors (20–50 years). The prevalence of antibodies did not differ iwth sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in Western Europe.     

Seroepidemiology of Helicobacter pylori infection in Greece

Helicobacter pylori infection is strongly associated with chronic gastritis and peptic ulceration. As the prevalence of H. pylori infection in southern European populations is not known, a serological survey of 1069 samples from three different age groups in the Greek population was carried out with an enzyme-linked immunosorbent assay (ELISA) for antibodies to these bacteria. The antigen was an ultracentrifuged supernate of whole cell sonicates of 5 isolates of H. pylori assessed by electrophoresis and by immunoblotting with negative and positive sera. The sensitivity of the test was 97.43% and the specificity 100% for IgG antibodies; IgA and IgM antibodies to the antigen preparation were not found. Antibodies to H. pylori were detected among 39.4% of children aged 1-10 years, 67.1% of recruits (20-27 years) and 70% of blood donors (20-50 years). The prevalence of antibodies did not differ with sex in each of the age groups. The proportion of individuals with antibodies to H. pylori was higher in the younger age groups than those reported for similar age groups in western Europe.     

Hepatitis A foci in children's collectives studied by using clinico-biochemical, virological and serological diagnostic methods

In 4 foci of hepatitis A (HA) at children's institutions in Moscow 218 children and 30 staff members were examined. Simultaneously with clinico-biochemical studies, specific IgM and IgG in the blood and hepatitis A virus (HAV) antigen in feces were determined by radioimmunoassay. Different forms of HA were detected in 29.1% of children in kindergartens, 19.4% of school children and 3.3% of adults, which was due to great differences in the size of the immune stratum among them (IgG to HAV was detected in 8-10% of children aged 3-6 years and in 83% of adults). In 2/3 of children with HA in the foci the disease was not accompanied by jaundice, 1/5 of them having the inapparent form of this infection. In 45% of the patients HAV antigen was detected in feces, irrespective of the form of HA, 5-14 days before the appearance of hyperfermentemia, and in 2/3 of them this antigen was also detected during the first 6 days after that. Simultaneously with an increase in aminotransferase activity, all of the HA patients showed the presence of specific IgM in their blood.     

Rubella-neutralizing and haemagglutinin-inhibiting antibodies in children of different ages

Rubella neutralization and haemagglutinin-inhibition tests were used to determine the incidence of rubella antibodies in the sera of 235 children and adolescents aged 1 month to 20 years. The tests showed good agreement in the detection of rubella antibodies resulting from acute infection. Maternal antibodies became undetectable within six months after birth. The proportion of children possessing rubella antibodies was found to be about 23% by the age of 5 years, rising sharply to 80% in the 6–12 years age group and 83% in the 13–20 years age group. Results indicate that the incidence of rubella infection may be higher in females than in males. The correlation between statements concerning a past history of rubella and immune status was poor, particularly in the older age groups. Any policy for vaccination against rubella must take into account the difficulties of identifying nonimmune persons in a large population.