Epidemic process of pertussis in Moscow

Materials reflecting the dynamics of pertussis morbidity during the period of 1958 - 2003 under the conditions of prolonged mass immunization of the child population with adsorbed DPT vaccine are presented. The planned vaccination of children led to the decrease of pertussis morbidity during the first 10 years, but groundless abstentions from vaccination during the 1980s - 1990s contributed to a sharp rise in morbidity among children of younger age groups. During the recent four years a rise in pertussis morbidity was registered in 2000 (71.79 per 100,000 of the population), followed by the most significant for the last 20 years drop in morbidity in 2002--down to 9.89. But in 2003 the growth of morbidity was again registered (38.67). Recently periodic rises and drops in morbidity occurred simultaneously with the increased coverage of children of younger age groups with vaccination. In recent years changes in the age structure of patients were observed: the specific proportion of school children increased (in 2003 morbidity rates in children aged 6 - 10 years were 288.6 - 270.7), simultaneously high morbidity among children aged up to one year (274.9) was registered. The specific proportion of pertussis-affected children aged above 7 years reached 65%. From the late 1990s until present in 87.1% of cases strains of serotype 1.0.3 prevailed in the population of B. pertussis strains. But in recent years the circulation of strains 1.2.3, spread in the prevaccination period and having toxicity similar to that of strains of serotype 1.0.3, while exceeding them in virulence, in sufficiently high proportion (7.0% in 2002) was noted. This was indicative of the possibility of the unfavorable development of the epidemic process of pertussis infection.     

Serological investigation of Bartonella henselae infections in clinically cat-scratch disease-suspected patients,patients with cardiovascular diseases,and healthy veterinary students in Japan

Seroprevalence of Bartonella henselae was investigated in Japan in 48 individuals clinically suspected of having cat-scratch disease (CSD), 159 patients with cardiovascular diseases, and 129 healthy veterinary students. Of 48 CSD-suspected patients examined, 19 (39.6%) were positive for B. henselae-IgG and 4 (8.3%) for B. henselae-IgM. Of 159 patients with cardiovascular diseases, 5 (3.1%) were positive for B. henselae-IgG. In healthy veterinary students, 14 of 129 (10.9%) were positive for B. henselae-IgG and 1 (0.8%) for B. henselae-IgM. The positive rates of B. henselae-IgG and -IgM in CSD-suspected patients were significantly higher than in other sources. Most CSD-suspected and healthy individuals who were positive for B. henselae antibody had had some contacts with cats. In CSD-suspected patients, the B. henselae positive rate in females was significantly higher than in males, and high seropositive rates to B. henselae were found in younger age groups.     

Epidemiological danger of patients with pulmonary tuberculosis and alcoholism refusing treatment

The comparative evaluation of the epidemiological danger of alcohol-addicted persons with pulmonary tuberculosis who evaded treatment (the test group of 133 persons) and that of tuberculosis patients receiving adequate treatment under hospital conditions (the control group of 162 patients) was made. The morbidity level among relations having contacts with the patients evading treatment exceeded the morbidity level in the families of tuberculosis patients undergoing adequate treatment 4.5-fold for adults and 3.4-fold for children and adolescents, the contamination level in the latter group being twice as high. Although no cases of the disease were registered in the foci of infection where sick persons evading treatment had low bacterial discharge, still the elevated level of infection among children and adolescents in these foci as compared with the foci where tuberculosis patients did not evade treatment (35.0% and 21.7% respectively) indicated that the foci of infection where such aggravating factors as alcohol addiction in the source of infection was present were rightly considered to be epidemiologically most dangerous. Persons suffering with both tuberculosis and alcoholism should be subjected to compulsory hospitalization as early as possible.     

Characteristics of the distribution of the markers of hepatitis B vir us infection among the healthy population of the Tadzhik SSR and Azerbaijan SSR

A total of 708 healthy persons in Tajikistan and 576 healthy persons in Azerbaijan, these groups comprising persons of both sexes and different age groups, were examined by the method of double gel immunodiffusion (the gel precipitation test) and by the passive hemagglutination test for the presence of the markers of hepatitis B virus (HBV) infection (HBsAg and HBeAg) and antibodies to them. This investigation showed that, in accordance with the level of hepatitis B morbidity, HBsAg was significantly more often detected among the population in Tajikistan (7.2%) than in Azerbaijan (2.8%). In both republics HBV carriers occurred most frequently among children aged 1-4 years (4.0% in Azerbaijan and 13.9% in Tajikistan), and among men more frequently than among women. In accordance with different intensity of the spread of HBV infection in the territories under comparison, differences in the age structure of the immune population were noted: in Tajikistan the formation of the immune layer occurred most frequently among younger age groups and in Azerbaijan, among senior adult age groups. The presence of a considerable percentage of persons with HBe-antigenemia (14.3-14.9% as determined by the gel precipitation test) among HBV carriers, observed in Tajikistan and in Azerbaijan, indicates that some of them have undetected chronic hepatitis B.     

Decreased Expression of miR-21, miR-26a,miR-29a,and miR-142-3p in CD4+ T Cells and Peripheral Blood from Tuberculosis Patients

The vast majority of Mycobacterium tuberculosis (M. tuberculosis) infected individuals are protected from developing tuberculosis and T cells are centrally involved in this process. MicroRNAs (miRNA) regulate T-cell functions and are biomarker candidates of disease susceptibility and treatment efficacy in M. tuberculosis infection. We determined the expression profile of 29 selected miRNAs in CD4⁺ T cells from tuberculosis patients and contacts with latent M. tuberculosis infection (LTBI). These analyses showed lower expression of miR-21, miR-26a, miR-29a, and miR-142-3p in CD4⁺ T cells from tuberculosis patients. Whole blood miRNA candidate analyses verified decreased expression of miR-26a, miR-29a, and miR-142-3p in children with tuberculosis as compared to healthy children with LTBI. Despite marked variances between individual donor samples, trends of increased miRNA candidate expression during treatment and recovery were observed. Functional in vitro analysis identified increased miR-21 and decreased miR-26a expression after re-stimulation of T cells. In vitro polarized Interleukin-17 positive T-cell clones showed activation-dependent miR-29a up-regulation. In order to characterize the role of miR-29a (a described suppressor of Interferon-γ in tuberculosis), we analyzed M. tuberculosis specific Interferon-γ expressing T cells in children with tuberculosis and healthy contacts but detected no correlation between miR-29a and Interferon-γ expression. Suppression of miR-29a in primary human T cells by antagomirs indicated no effect on Interferon-γ expression after in vitro activation. Finally, classification of miRNA targets revealed only a moderate overlap between the candidates. This may reflect differential roles of miR-21, miR-26a, miR-29a, and miR-142-3p in T-cell immunity against M. tuberculosis infection and disease.     

Impact of Latent Infection Treatment in Indigenous Populations

The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN) database, and the contacts’ data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI) multidisciplinary teams, according to SESAI’s instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02–1.04) and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59–3.22). The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST) ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07–1.17), age (RR: 1.01, 95% CI: 1.00–1.03), and treatment of latent infection (RR: 0.03, 95% CI: 0.01–0.27). The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33–182). In contacts with TST ≥10 mm, 10 (95% CI: 6–19) latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities.     

Performance of the Interferon Gamma Release Assays in Tuberculosis Disease in Children Five Years Old or Less

Interferon Gamma Release Assays (IGRAs) were developed for the indirect or immunologic diagnosis of tuberculosis infection; however, they have also been used to assist in difficult to diagnose cases of tuberculosis disease in adults, and to a lesser extent, in children, especially in those under 5 years old. We evaluated the utility of using an IGRA in pediatric tuberculosis in younger children in a hospital setting. The diagnostic accuracy of T-SPOT.TB and TST was assessed in 117 children with active tuberculosis and 413 children with respiratory tract infection. Sensitivity and specificity were calculated for the tests used individually and together. Concordance was also calculated. Sensitivity of T-SPOT.TB (82.9%) was higher than TST (78.6% using a 5mm cut-off), especially in children confirmed to have TB. T-SPOT.TB was more specific than TST using a 5mm cut-off (96.1% vs. 70.9%). Combining T-SPOT.TB and TST results improved the sensitivity to 96.6%. In conclusion, the results of the current study indicate that T-SPOT.TB has good sensitivity and specificity, supporting its use among patients of this age. A combination of IGRA and TST would be useful additions to assist in the diagnosis of childhood TB.     

Chest radiography findings in primary pulmonary tuberculosis in children

Plain chest radiography plays a major role in the diagnosis and follow-up of pulmonary tuberculosis in childhood. The aim of our study was to investigate the distribution of characteristic chest radiographic findings at diagnosis in children with pulmonary tuberculosis. The age of the patients and the type and localization of radiographic changes at admission were retrospectively analyzed. We reviewed chest radiographs in 204 children admitted from January 1, 1991 until June 30, 1994 for newly diagnosed pulmonary tuberculosis. Mean age +/- SD was 6.4 +/- 4.2 years (range 0-14). The most common lesion was lymphadenopathy (found in 172 children, 84.3%). It was significantly more common in the youngest age group (0-4 years) and was more significantly present in the right hilo-mediastinal region. Parenchymal changes were found in 125 children (61.3%). They were also significantly more common in the young age group and in the right lung. Other less common lesions included pleuritis, atelectasis, destructive-cavitary lesions and miliary dissemination. In conclusion, the leading radiographic finding in pulmonary tuberculosis in childhood remains hilar lymphadenopathy, but parenchymal changes are clearly strongly present, and should be sought and appreciated in the diagnostic work-up for pulmonary tuberculosis in childhood.     

Family incidence of type B hepatitis

Family incidence of HBsAg-positive viral hepatitis was confirmed to be high. In 499 families with a type B viral hepatitis patient, type B viral hepatitis morbidity among 1116 contacts amounted to 2.24% within 6 months of the primary patients' hospitalization (being 188.2 times higher than semiannual morbidity of the population of the Czech Socialist Republic, CSR) and the prevalence of HBsAg amounted to 8.96% (being 22.4 times higher than among the population of CSR). On deducting positive findings at first blood samplings, which at least partially eliminated individuals who could themselves have been the source of infection for the first patient in each family, the rate for contact cases equalled 0.70% (58.8 times higher morbidity than among the population) and the rate for HBsAg prevalence equalled 2.50% (6.25 times higher than among the population). Among 917 members of 335 families where a case of HBsAg-negative viral hepatitis occured, 0.32% developed HBsAg-positive viral hepatitis within 6 months (26.8 times higher morbidity than population morbidity) and the HBsAg prevalence was 2.94% (7.35 greater than among the population). On deducting the first positive findings no clinical illness remained and HBsAg prevalence equalle 0.98% (2.45 times higher than among the population). The highest HBsAg prevalence was found among contacts aged 0-5 years (17.09% for the whole period, 3.41% after deducting first positive findings) and 40 years and over (10.82% and 3.39%, respectively). Type B viral hepatitis morbidity was again highest in the age groups of 0-5 years (5.12%) and 40 years and over (2.54%) for the whole period. On deducting first positive findings, the 40+ years group displayed the highest morbidity (1.27%), whereas the 0-5 years group displayed zero morbidity. Disclosure of the mechanisms of nonparenteral or inapparently parenteral transmission specific for family environments would be important for the prospect of introducing adequate measures to limit or prevent the spread of type B viral hepatitis.     

Epidemiological patterns of tuberculosis in Croatia in the period 1996-2005

The last comprehensive publication on tuberculosis in Croatia and the earliest impact of war, besides the yearly routine reports, was done in 1996 in Croatian. We were, therefore, interested to explore incidence trends and to highlight the early post-war tuberculosis epidemiological patterns in the next ten years period (1996-2005). A retrospective analysis of epidemiological data on all registered tuberculosis cases in Croatia searching the databases of 21 Croatian Public Health Institutes and the National Tuberculosis Registry was made. During the study period, the total tuberculosis incidence rates in Croatia dropped from 45 to 25.8/100 000 inhabitants. The average highest age-specific rates were recorded in the age group > or = 65 years being in decrease in all age groups. Paediatric cases (0-14 years) represented 4.5% of all cases. Tuberculosis cases among males were recorded in 64% cases, and 83.6% were indigenous population. Tuberculosis was bacteriologically confirmed in 67.7% cases. A low proportion of drug resistance (3.3%) was recorded. During 1985-2005, 56 tuberculosis cases among 242 AIDS cases were reported. Tuberculosis mortality showed a decreasing trend (p < 0.001). However, tuberculosis has still had the highest mortality rates among infectious diseases in Croatia. Despite the War chain of events and tuberculosis programmatic changes, tuberculosis incidence rates in Croatia have been decreasing but they are still far away from national target, incidence rate of 10/100 000 declared in 1998 and much higher than in European Union and Western Europe. Tuberculosis among children, resistance to tuberculosis drugs and HIV prevalence, significant problems in many European countries, have not caused problems in tuberculosis control in Croatia. This favourable epidemiological situation must be kept and improved through strengthened tuberculosis control measures.     

Characteristics and trends in the development of an epidemic process of Sonne and Flexner dysentery among preschool children

The results of studies indicate that the morbidity rates of dysentery among children attending preschool institutions and children brought up at home converged in recent years. This phenomenon was most pronounced among children of the kindergarten age group. At the same time dysentery caused by Sh. sonnei and Sh. flexnery produced a higher morbidity rate among children attending nursery in comparison with that among children of the same age group brought up at home. Group infections in preschool institutions were caused by Sh. sonnei in 89.1% of cases and by Sh. flexneri in 10.9% of cases. Outbreaks due to the transfer of infection through everyday contacts were observed only in dysentery caused by Sh. sonnei, constituting 71.4% of the total number of dysentery outbreaks.     

Morbidity and mortality in acute viral hepatitides in a hyperendemic region. The role of viral hepatitis E

Official annual statistical data on morbidity in acute viral hepatitides (AVH), including the number of lethal cases, for 1985-1995 were analyzed. Mortality rates per 100,000 of the population at the period of 11 years were calculated for different age groups, sex and the place of residence. 396 and 99 patients were examined for the presence of serological markers of hepatitides A, B and E, respectively, at the periods of epidemic rises in morbidity and satisfactory epidemic situation. In the course of 11 years AVH caused the death of 22,405 persons. In 1985-1987 the average mortality level (ML) reached 12.3-17.8 per 100,000 of the population (with morbidity being 1,200-1,400 and was essentially higher among the rural population in comparison with the urban population. During these years the highest ML, was registered among children aged 0-2 years (190-50 per 100,000) and, among adults, mainly among women aged 20-29 years (21.4-19.6 per 100,000). During the years when the epidemic of AVH was absent, ML among these groups was essentially lower: 40-20 among children aged 0-2 years and 4-5 among women aged 20-29 years. In 1987 in the Fergana Valley hepatitis E was detected in 72.2% of all examined patients, and in the southern areas of the country in 68.7%. A sharp rise on mortality among women of the productive age at the period of the epidemic rise of AVH morbidity in the endemic region indicated that this epidemic was linked with hepatitis E. High ML among young children may be indicative of a highly unfavorable course of hepatitis E in the group of infants, which had never been registered before. This newly established regularity may be used for the retrospective diagnostics of the outbreak of hepatitis E.     

Role of carriers of the hepatitis B surface antigen as possible sources of infection in children's collectives

The complex clinico-epidemiological and laboratory surveys of the children and the staff in 71 institutions for children of preschool age were made at the period of increased viral hepatitis morbidity in these institutions, and the dynamic observations of 11 children's institutions having children with prolonged HBs-antigenemia were carried out. In the foci of viral hepatitis the level of antigenemia in the children and the staff exceeded (p less than 0.01) that in the control group. The dynamic observations (lasting up to 6 years) of the groups containing HBsAg-carriers revealed that 6 children, previously HBsAg-negative, showed a short-term HBs-antigenemia in the absence of any evidence of the parenteral (instrumental) route of infection. This fact indicates that the role of HBsAg-carriers as the possible sources contributing to the transfer of hepatitis B through everyday contacts in children's institutions cannot be ruled out. Periodic clinico-epidemiological and laboratory surveys of groups with HBsAg-carriers are recommended.     

Pediatric urolithiasis in Croatia

A retrospective review was performed of the records of 148 Croatian children with urolithiasis treated between 1989 and 2003. The study evaluated age, gender, family history, clinical symptoms, location of stone, laboratory findings, stone composition, mode of treatment and compared our results with data from higher and lower socio-economic countries. The mean age of our patients was 9.38 years (10 months to 18 years). Thirty-seven children (25%) were less than 5 years (group 1), 44 (29.7%) were between 5 and 10 years (group 2) and 67 (45.3%) were older than 10 years of age (group 3). There were 60 girls and 88 boys with overall male to female ratio of 1.47. Abdominal pain (83%) and haematuria (59.5%) were the main symptoms in the groups 2 and 3. Urinary tract infection was predominant symptom in the group 1 (62.1%). Calculi were located in the kidney in 90 children (60.8%), in the ureter in 39 (26.4%), in the bladder in 8 (5.4%). Urinary tract anomalies with or without infection were associate with a greater frequency of urolithiasis in the youngest age group and hypercalciuria was predominant cause in children over 5. Stone analysis was performed in 80 children. Predominant constituent of stones was calcium oxalate (48.7%), followed by struvite (25%), calcium phosphate (13.7%), cystine (10%) and uric acid (1.2%). Calcium oxalate stones were most common in all age groups. Struvite stones were most prevalent in the children younger than 5 years of age. Most patients (33.1%) underwent surgery for removal of their calculi. In 31.8% of children stones were passed spontaneously and the highest spontaneous passage rate was in the group 3 (37.3%). Stone composition, location and etiology in Croatian children are similar to those in developed Western countries.     

Measles morbidity among children inoculated against this infection

In the serological survey of 2009 children immunized against measles 285 children (14.2%) were found to be seronegative to this infection in the hemagglutination inhibition test with 4 hemagglutinating units of the antigen. Among 1724 immunized children showing positive response to vaccination and placed under dynamic observation for 11 years, 2 cases of measles were registered. At the same time, in the dynamic observation of 111 seronegative children 66 measles cases (59.5%) were registered during the above period, while among 169 children, also seronegative, but receiving booster immunization against measles, morbidity rate was only 1.2%. In some vaccinees the decrease of postvaccinal immunity to seronegative values was observed, but such decrease had no essential influence on the morbidity level among the vaccines. The increase of measles morbidity among schoolchildren immunized against this infection was due not to the decrease of their postvaccinal immunity, but to their concentration in schools and to their more intensive contacts with the sources of infection in comparison with children of preschool age.     

Prevalence of enterotoxigenic Bacteroides fragilis in patients with diarrhea: a controlled study

In this age matched controlled study performed in Malatya, a city in east region of Turkey, enterotoxigenic Bacteroides fragilis (ETBF) was investigated in stool specimens obtained from children and adults with and without diarrhea. A nested polymerase chain reaction (PCR) method was used to detect the enterotoxin gene of B. fragilis in a total of 418 stool samples, including 221 samples from 117 children (aged 0-16 years) and 104 adults (aged >16 years) with diarrhea, and 197 samples from 102 children and 95 adults as control group that was the same age group with those having diarrhea. ETBF was detected in 13 of 117 diarrheal children (11.1%) and 8 of 102 control children (7.8%) (P>0.05). In children aged 1-5 years, the rate of ETBF was significantly higher in patients than in controls (25% versus 9.5%, respectively; P<0.05). On the other hand ETBF was detected similar rates (2.2% and 2.4%, respectively) in children younger than 1 year in both patients and controls. ETBF positivity was not significantly difference between patient and control groups who were older than 5 years of age and adults. The frequency of ETBF in the controls was slightly higher in older persons than in younger ones; however, it was not significant. The rate of ETBF as the only enteropathogen in the patients with ETBF was significantly higher than in controls with ETBF (88% versus 39%, respectively; P<0.02). We found that in east region of Turkey, the prevalence of ETBF was higher in the childhood diarrhea, particularly in aged 1-5. As the only enteropathogen, ETBF may play an important role in diarrheal diseases. Persons after 6 years old can be carrier for ETBF regardless diarrhea.     

Determining Mycobacterium tuberculosis Infection among BCG-Immunised Ugandan Children by T-SPOT.TB and Tuberculin Skin Testing

Background

Children with latent tuberculosis infection (LTBI) represent a huge reservoir for future disease. We wished to determine Mycobacterium tuberculosis (M.tb) infection prevalence among BCG-immunised five-year-old children in Entebbe, Uganda, but there are limited data on the performance of immunoassays for diagnosis of tuberculosis infection in children in endemic settings. We therefore evaluated agreement between a commercial interferon gamma release assay (T-SPOT.TB) and the tuberculin skin test (TST; 2 units RT-23 tuberculin; positive defined as diameter ≥10 mm), along with the reproducibility of T-SPOT.TB on short-term follow-up, in this population.

Methodology/Principal Findings

We recruited 907 children of which 56 were household contacts of TB patients. They were tested with T-SPOT.TB at age five years and then re-examined with T-SPOT.TB (n = 405) and TST (n = 319) approximately three weeks later. The principal outcome measures were T-SPOT.TB and TST positivity. At five years, 88 (9.7%) children tested positive by T-SPOT.TB. More than half of those that were T-SPOT.TB positive at five years were negative at follow-up, whereas 96% of baseline negatives were consistently negative. We observed somewhat better agreement between initial and follow-up T-SPOT.TB results among household TB contacts (κ = 0.77) than among non-contacts (κ = 0.39). Agreement between T-SPOT.TB and TST was weak (κ = 0.28 and κ = 0.40 for T-SPOT.TB at 5 years and follow-up, respectively). Of 28 children who were positive on both T-SPOT.TB tests, 14 (50%) had a negative TST. Analysis of spot counts showed high levels of instability in responses between baseline and follow-up, indicating variability in circulating numbers of T cells specific for certain M.tb antigens.

Conclusions/Significance

We found that T-SPOT.TB positives are unstable over a three-week follow-up interval, and that TST compares poorly with T-SPOT.TB, making the categorisation of children as TB-infected or TB-uninfected difficult. Existing tools for the diagnosis of TB infection are unsatisfactory in determining infection among children in this setting.     

Epidemiological characterisation of acute and chronic hepatitis B in Uzbekistan

The epidemiological survey of 126 foci with patients having acute hepatitis B (AHB) and 120 foci with patients having chronic hepatitis B (CHB) was conducted. The observation of the susceptible members of the family showed that a significantly higher level of infection was found in persons having contacts with CHB patients (44.4 +/- 2.3%) in comparison with the members of the families of AHB patients (33.2 +/- 2.3%). The study revealed that children under 14 years were actively involved into the epidemic process; in these children the highest levels of infection were observed in the families of AHB patients (40.2 +/- 3.7%) and CHB patients (57.1 +/- 3.5%). High detection rate of HbsAg were noted in brothers and sisters in the foci of AHB (42.3 +/- 6.4%) and the foci of CHB (52.3 +/- 5.4%), also in parents: 32.4 +/- 5.2% and 46.5 +/- 4.2%, in children: 28.8 +/- 3.4% and 35.6 +/- 3.6% respectively.     

The spread of HB virus infection in familial foci in a territory hyperendemic for hepatitis B

Epidemiological surveillance with the use of highly sensitive techniques for the indication of markers of hepatitis B (HB) virus infection in their dynamics has made it possible to find out that at a territory, hypersensitive for HB, along the existing high risk of this infection as the result of parenteral medical manipulations the intensive natural transmission of HB virus infection occurs under the conditions of everyday contacts with sources of the infection, patients with chronic forms of HB virus infection being of the highest epidemic importance. Under these conditions, children aged up to 7 years have been found to belong to the highest risk group. As a consequence, children of this age should be covered in future by specific preventive measures against HB. The spread of the epidemic process of HB virus infection in family foci is usually manifested by anicteric (usually not diagnosed) forms of this infection. All these circumstances make it expedient to develop antiepidemic and prophylactic measures in the foci of HB.