Measles Virus Immunity Level Study in Particular Population Groups of the Republic of Guinea Within the Framework of Global Measles Elimination Program. Report 2

Within a framework of the state measles elimination program, in April, 2018 a level of measles herd immunity was assessed in 1899 Moscow hospital medical workers aged from 19 to 69 years and older. All subjects enrolled in the study were vaccinated against measles or recovered after measles infection. Serum samples were collected from subjects and examined by ELISA for measles IgG antibodies with the Vector-Best IgG-measle test system (Russia). It was found that 278 (14.6%) and 1621 (85.4%) subjects were seronegative (< 0.18 IU/mL) and seropositive (> 0.18 IU/ml), respectively. Age-related group distribution of 1855 serum samples revealed that percentage of seronegative subjects was in: aged 19—23 years was -38.5%; 24-28 and 29-33 years - 22.2%; 34-38 years - 27.5%; 39-43 years - 25.8%; 44-48 years - 16.8%; 49-53 and 54-58 years — 8.6% and 8.3%, respectively; 59-63 years old — 4.9%; 64-68 and over 69 years old — 0%. Moreover, mean level of measles IgG antibodies increased proportionally to age of medical workers from 0.58 IU/ml (19-23 years) to 2.94-2.72 IU/ml (64-68 and over 69 years). The data obtained indicate that a cohort of measles susceptible subjects (from 38.5% to 16.8%), respectively, is identified among young and middle age (from 19 to 48 years) individuals. It is assumed that two-dose measles vaccination in childhood does not contribute to the long-term preservation of protective levels of measles antibodies, thereby justifying a need to administer a three-dose measles vaccine.

Section: Discussionunclassified

Level of measles herd immunity assessed in hospital medical workers within a framework of the state measles elimination program

Костинов

Филатов

Журавлев

et al. 2020

“…Самый низкий показатель серопревалентности установлен среди детей I и II возрастных групп: совокупно их доля составила 47,8% (p < 0,05). Как и в предыдущие годы [3,4,5], дети до 5 лет остаются самой уязвимой когортой населения, несмотря на то, что в 2018 г. в ГР была проведена кампания дополнительной иммунизации.…”

Section: таблица 1 выявление специфических Igм к вирусу кори в образцах сывороток крови жителей гвинейской республики разных возрастных гunclassified

2019–2020 measles in the Republic of Guinea: epidemic features and herd immunity

Лаврентьева

Бичурина

Antipova

et al. 2021

Self Cite

Introduction. In connection with the Ebola epidemic in the West African countries, including the Republic of Guinea, a failure in implementing measles immunization program was noted. A proportion of measles seronegative subjects in 2017 was 52.4% of total examined individuals. In 2018, a high proportion of measles cases among children aged 1–5 years (61.6%) was identified. In order to stop the 2018 outbreak, the Supplemental Immunization Campaign was conducted in the Konakri and Nzerekore prefectures in the Republic of Guinea. The aim of this study was to examine the 2019–2020 measles epidemic situation and assess the measles population immunity in the Republic of Guinea. Materials and methods. Measles-specific antibodies were examined in 1697 blood serum samples collected from residents of different regions of the Republic of Guinea, aged from 7 months to 76 years, obtained in 2019–2020, and tested retrospectively. The ELISA test systems Anti-Measles Virus ELISA (IgM) Euroimmun and Anti-Measles Virus ELISA (IgG) Euroimmun (Germany) were used. The presence of serum IgM measles antibodies was considered as acute measles infection. Statistical analysis was performed using the software package Statistica 6.0. Results. Blood sera (n = 638) were tested for IgM-measles, and in 46.6% of cases the diagnosis was confirmed by laboratory tests. The biggest proportion of the total cases (61.6%) was found in children aged 1–4 years. The second most important age group was 5–9 years of age, the third is children under 1 year: 18.5% and 11.8% of the total number of patients, respectively. Measles infection was registered in vaccinated patients in 7.4% of the total number of laboratory-confirmed cases. 1059 subjects were examined for IgG measles antibody. The lowest seroprevalence rate was found among children under 4 years of age (47.8%). The highest (85.5%) was found among subjects of 40 years old and older. Conclusion. Measles in GR remains a poorly controlled infection. As in the previous years of observation (2017–2018), children under 5 years of age are the most vulnerable cohort of the population, despite the 2018 DI campaign conducted in a number of GR territories. More problems with the measles control in the Republic of Guinea are expected in the period from 2021, as along with the COVID-19 epidemic, Ebola is repeatedly registered in the country. The Republic of Guinea particularly requires assistance from the international community to implement the WHO measles elimination program on a global scale.

“…Подъем заболеваемости связан со снижением охвата плановой вакцинацией с 90,5% в 2012 г. до 52% в 2015 г. [3,4,7]. Программа вакцинопрофилактики кори была нарушена вследствие развития гуманитарного кризиса в странах, вовлеченных в эпидемию лихорадки Эбола [9,11].…”

Section: Abstract: Measles Measles Elimination Program Africa Vaccination Revaccinationunclassified

Detection of measles cases in the Republic of Guinea in 2017–2018

Лаврентьева

Бичурина

Антипова

et al. 2020

Self Cite

In 2017, WHO reported 596 confirmed measles cases in Guinea Republic connected to the 2016-2017 epidemic outbreak that was stopped after additional immunization (SIA) against measles in two provinces of the country. Improving the effectiveness of SIA is associated with the identification of epidemiologically significant groups of the population. The aim of the study was to analyze 2017-2018 measles cases and assess population immunity to measles virus in the Republic of Guinea. Materials and methods. A total of 810 blood serum samples collected from patients with maculo-papular rash and clinical diagnosis " measles?" were tested for measles virus-specific IgM-and IgG antibody level. 445 sera of conditionally healthy individuals aged 7 months to 67 years were examined for anti-measles virus IgG antibody level. Immunoglobulins of classes M and G were detected by ELISA with test systems Anti-Measles Virus ELISA (IgM) Euroimmun (Germany) and Anti-Measles Virus ELISA(IgG) Euroimmun (Germany). Results and discussion.In 2017-2018, the epidemic process of the measles in the Republic of Guinea proceeded very intensively, being markedly prevalent in children among age groups. In 2018, more than half of the cases (61.6%) were identified in children aged 1 to 5 years old; the second most abundant age group was children under one year (18.6%), probably due to violated measles vaccination, which in GR are subject to children of nine months of age. It was found that 16.4% of patients (60 out of 366) had documented data on measles vaccination. Potentially, high proportion of measles cases among pre-vaccinated subjects was due to insufficient immune response to a single immunization in children of 9 months of age.Moreover, lowered vaccine-related properties might also be violated "cold chain" during vaccine transportation occurring in tropical climate. Analyzing 445 subjects revealed that total number of measles virus seronegative subjects was 8.3%. However, the vast majority of them were children and young adults aged 7 months to 22 years, where 52.4% of seronegative subjects were identified. Thus, the data obtained indicate that intensive measles virus circulation in human population was continued that necessitate interventions for improving epidemiological surveillance, extend routine measles vaccination coverage and conduct SIAs against measles in GR.