Despite vaccine availability, rotaviruses are still responsible for most severe cases of diarrhea in children under five in low- and middle-income countries, causing more than 200 deaths per year.
This is what a broad study carried out by the Global Pediatric Diarrhea Surveillance Network, coordinated by the World Health Organization (WHO) and with the participation of the Oswaldo Cruz Institute (IOC/Fiocruz).
Published in scientific journal 'BMJ Global Health', the research presents data from the monitoring carried out between 2017 and 2019 in sentinel hospitals in 28 countries, covering the regions of the Americas, Africa, Europe, Asia and Oceania.
The results of the work reinforce the importance of immunization. Considering the countries as a whole, rotavirus was responsible for 33% of hospitalizations. However, the impact of the pathogen dropped by half in places where immunization was offered.
Biologist Irene Maciel performing genetic analysis using the real-time PCR technique at the Laboratory of IOC. Photo: Gutenberg Brito
“This result makes clear the positive impact of the rotavirus vaccine and the need to strengthen and expand this immunization. The WHO recommends that all countries offer the vaccine, however, less than half of the children born in 2018 were vaccinated”, points out virologist José Paulo Gagliardi Leite, researcher at the Comparative and Environmental Virology Laboratory of the IOC and one of the authors of the study.
In addition to rotaviruses, the survey identified other pathogens that cause a significant portion of children's hospitalizations: Shigella bacteria (responsible for 10% of cases), noroviruses (detected in 6,5% of cases) and adenoviruses (confirmed in 5,5% of cases). % of cases).
Based on the data collected, the researchers estimated the number of deaths of children under 5 years of age caused annually by each of the microorganisms in low- and middle-income countries: 208 by rotavirus; 63 thousand for Shigella; 37 for adenoviruses; and 36 for norovirus.
“Diarrhea is one of the top five causes of death for children under five worldwide. There are more than a thousand deaths a day. Knowing the microorganisms that cause the disease is important to devise more effective prevention and control strategies,” says virologist Tulio Fumian, who is also a researcher at the Comparative and Environmental Virology Laboratory of the IOC and one of the authors of the work.
“Thinking about new vaccines, there are already studies underway to develop immunizers against Shigella and norovirus. Based on the data, we see that adenoviruses can also be considered in these initiatives”, adds José Paulo.
The American continent was the only region surveyed where rotavirus was not the main cause of hospitalizations. In South America, most hospitalizations were due to norovirus. In Central America, Shigella bacteria were more prevalent.
The study highlights that the six countries in the region with sentinel hospitals included in the survey (Honduras, Nicaragua, Bolivia, Ecuador, Peru and Paraguay) have offered the rotavirus vaccine in their national immunization programs since 2010.
According to the researchers, the data observed in the research are compatible with the analyzes carried out in Brazil by the Laboratory of Comparative and Environmental Virology of the IOC, which acts as a regional reference center for rotavirus infections for the Ministry of Health and the Pan American Health Organization (PAHO/WHO), receiving around 11 samples per year from XNUMX states in the South, Southeast and Northeast of the country, in addition to samples from Latin American countries (Bolivia, Ecuador, Paraguay and Peru).
“As a reference, we analyze not only severe cases, which require hospitalization, but also outpatient occurrences, especially in outbreak situations. In Brazil, in our last studies, we detected approximately twice as many norovirus infections compared to rotaviruses”, clarifies Tulio.
Conference of genetic analysis results: Laboratory of IOC receives samples from different parts of the country and Latin America. Photo: Gutemberg Brito
The researcher makes a warning: it is necessary to increase vaccination coverage in the country. “In the 2022 analyses, we observed an increase in rotavirus infections. In addition, as the country had low vaccination coverage in 2020 and 2021, it is essential to reverse this decline”, points out the researcher.
Introduced in the National Immunization Program (PNI) in March 2006, the vaccine for rotavirus is administered orally, at 2 and 4 months of life, to protect against acute gastroenteritis caused by the pathogen.
In 2015, the vaccination rate reached 95% of children under one year old. However, it began to decline from 2016 onwards and the situation worsened during the Covid-19 pandemic. In 2021, only 71% of the little ones were immunized.
“In general, coverage is lower in the North and Northeast regions”, stresses José Paulo.
In addition to vaccination, the researchers highlight other important measures to prevent cases of diarrhea.
“Sanitation is fundamental and has a great impact on cases of bacterial diarrhea. Regarding rotaviruses, noroviruses and adenoviruses, due to their biological characteristics, they can remain infectious for long periods in the environment. Hand hygiene, cleaning and disinfection of places where there may be contamination by feces and vomit is very important. Children with diarrhea should also be kept away from the day care center, to prevent outbreaks from occurring”, lists Leite.
With funding from the Bill & Melinda Gates Foundation and the Global Vaccine Alliance (Gavi), the Global Pediatric Diarrhea Surveillance Network has been continuously monitoring since 2017 hospitalizations of children under five for diarrhea in the 33 sentinel hospitals established.
On the map, the countries with sentinel hospitals included in the survey, in the different regions. The graphs show the percentage of cases attributed to each of the pathogens. Source: article 'Aetiology and incidence of diarrhea requiring hospitalization in children under 5 years of age in 28 low-income and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network'
Samples selected for analysis are sent to one of the eight WHO Regional Reference Laboratories for Rotavirus, among them the Laboratory of Comparative and Environmental Virology of the IOC. The identification of pathogens is carried out through genetic analysis, using the methodology of real-time PCR.
“The test makes it possible to identify 16 pathogens simultaneously, including bacteria, parasites and viruses, which cause acute diarrhea. It also detects microorganism subtypes, such as different species of bacteria or viral genotypes, with a total of 73 variations”, explains biologist Irene Araújo Maciel, technologist responsible for the analysis of the project at the Laboratorio do IOC.
The results obtained are sent to the University of Virginia, in the United States, where the test (called 'Tac Array Card') was developed and where scientists carry out the statistical analysis of the study.
The publication of the first research results was delayed by the Covid-19 pandemic, as health centers and laboratories needed to dedicate efforts to combating SARS-CoV-2. Currently, scientists are analyzing samples for 2020, but the goal is to perform real-time analyzes in the coming years.
“At this moment, we still have the reflection of the pandemic. But in the near future, we hope to do a real-time diagnosis. This will allow for a panoramic and geographical view of the dissemination of microorganisms on the five continents, to monitor outbreaks and compare what happens in different regions”, says José Paulo.
Diarrhea is one of the top five causes of death for children under five worldwide. Photograph: JaCZhou
According to the Ministry of Health, the classic form of rotavirus disease, especially in the age range of six months to two years, is characterized by an abrupt form of vomiting, most of the time there is diarrhea and the presence of high fever. Mild forms may occur in adults and forms that do not show symptoms in newborns and during the first four months of life.
Rotaviruses are transmitted by fecal-oral (stool-mouth) contact, person-to-person contact, and through contaminated water, food, and objects. There is a high concentration of the virus that causes the disease in the feces of infected children. Vomiting is also responsible for the spread of rotavirus and norovirus.
Part of the national vaccination schedule, the vaccine against rotavirus (VORH) is available free of charge in the Unified Health System (SUS). It is essential to be administered at 2 and 4 months of life for babies.
It is also necessary to follow basic care with personal and domestic hygiene, such as always washing your hands before and after using the bathroom, changing diapers, handling/preparing food, breastfeeding, handling dirty materials/objects, touching animals, in addition to washing and disinfect surfaces, utensils and equipment used in food preparation.
The Ministry of Health reinforces that maintaining breastfeeding increases children's resistance against various diseases, including diarrhea, and therefore reinforces the recommendation to avoid early weaning.
Despite vaccine availability, rotaviruses are still responsible for most severe cases of diarrhea in children under five in low- and middle-income countries, causing more than 200 deaths per year.
This is what a broad study carried out by the Global Pediatric Diarrhea Surveillance Network, coordinated by the World Health Organization (WHO) and with the participation of the Oswaldo Cruz Institute (IOC/Fiocruz).
Published in scientific journal 'BMJ Global Health', the research presents data from the monitoring carried out between 2017 and 2019 in sentinel hospitals in 28 countries, covering the regions of the Americas, Africa, Europe, Asia and Oceania.
The results of the work reinforce the importance of immunization. Considering the countries as a whole, rotavirus was responsible for 33% of hospitalizations. However, the impact of the pathogen dropped by half in places where immunization was offered.
Biologist Irene Maciel performing genetic analysis using the real-time PCR technique at the Laboratory of IOC. Photo: Gutenberg Brito
“This result makes clear the positive impact of the rotavirus vaccine and the need to strengthen and expand this immunization. The WHO recommends that all countries offer the vaccine, however, less than half of the children born in 2018 were vaccinated”, points out virologist José Paulo Gagliardi Leite, researcher at the Comparative and Environmental Virology Laboratory of the IOC and one of the authors of the study.
In addition to rotaviruses, the survey identified other pathogens that cause a significant portion of children's hospitalizations: Shigella bacteria (responsible for 10% of cases), noroviruses (detected in 6,5% of cases) and adenoviruses (confirmed in 5,5% of cases). % of cases).
Based on the data collected, the researchers estimated the number of deaths of children under 5 years of age caused annually by each of the microorganisms in low- and middle-income countries: 208 by rotavirus; 63 thousand for Shigella; 37 for adenoviruses; and 36 for norovirus.
“Diarrhea is one of the top five causes of death for children under five worldwide. There are more than a thousand deaths a day. Knowing the microorganisms that cause the disease is important to devise more effective prevention and control strategies,” says virologist Tulio Fumian, who is also a researcher at the Comparative and Environmental Virology Laboratory of the IOC and one of the authors of the work.
“Thinking about new vaccines, there are already studies underway to develop immunizers against Shigella and norovirus. Based on the data, we see that adenoviruses can also be considered in these initiatives”, adds José Paulo.
The American continent was the only region surveyed where rotavirus was not the main cause of hospitalizations. In South America, most hospitalizations were due to norovirus. In Central America, Shigella bacteria were more prevalent.
The study highlights that the six countries in the region with sentinel hospitals included in the survey (Honduras, Nicaragua, Bolivia, Ecuador, Peru and Paraguay) have offered the rotavirus vaccine in their national immunization programs since 2010.
According to the researchers, the data observed in the research are compatible with the analyzes carried out in Brazil by the Laboratory of Comparative and Environmental Virology of the IOC, which acts as a regional reference center for rotavirus infections for the Ministry of Health and the Pan American Health Organization (PAHO/WHO), receiving around 11 samples per year from XNUMX states in the South, Southeast and Northeast of the country, in addition to samples from Latin American countries (Bolivia, Ecuador, Paraguay and Peru).
“As a reference, we analyze not only severe cases, which require hospitalization, but also outpatient occurrences, especially in outbreak situations. In Brazil, in our last studies, we detected approximately twice as many norovirus infections compared to rotaviruses”, clarifies Tulio.
Conference of genetic analysis results: Laboratory of IOC receives samples from different parts of the country and Latin America. Photo: Gutemberg Brito
The researcher makes a warning: it is necessary to increase vaccination coverage in the country. “In the 2022 analyses, we observed an increase in rotavirus infections. In addition, as the country had low vaccination coverage in 2020 and 2021, it is essential to reverse this decline”, points out the researcher.
Introduced in the National Immunization Program (PNI) in March 2006, the vaccine for rotavirus is administered orally, at 2 and 4 months of life, to protect against acute gastroenteritis caused by the pathogen.
In 2015, the vaccination rate reached 95% of children under one year old. However, it began to decline from 2016 onwards and the situation worsened during the Covid-19 pandemic. In 2021, only 71% of the little ones were immunized.
“In general, coverage is lower in the North and Northeast regions”, stresses José Paulo.
In addition to vaccination, the researchers highlight other important measures to prevent cases of diarrhea.
“Sanitation is fundamental and has a great impact on cases of bacterial diarrhea. Regarding rotaviruses, noroviruses and adenoviruses, due to their biological characteristics, they can remain infectious for long periods in the environment. Hand hygiene, cleaning and disinfection of places where there may be contamination by feces and vomit is very important. Children with diarrhea should also be kept away from the day care center, to prevent outbreaks from occurring”, lists Leite.
With funding from the Bill & Melinda Gates Foundation and the Global Vaccine Alliance (Gavi), the Global Pediatric Diarrhea Surveillance Network has been continuously monitoring since 2017 hospitalizations of children under five for diarrhea in the 33 sentinel hospitals established.
On the map, the countries with sentinel hospitals included in the survey, in the different regions. The graphs show the percentage of cases attributed to each of the pathogens. Source: article 'Aetiology and incidence of diarrhea requiring hospitalization in children under 5 years of age in 28 low-income and middle-income countries: findings from the Global Pediatric Diarrhea Surveillance network'
Samples selected for analysis are sent to one of the eight WHO Regional Reference Laboratories for Rotavirus, among them the Laboratory of Comparative and Environmental Virology of the IOC. The identification of pathogens is carried out through genetic analysis, using the methodology of real-time PCR.
“The test makes it possible to identify 16 pathogens simultaneously, including bacteria, parasites and viruses, which cause acute diarrhea. It also detects microorganism subtypes, such as different species of bacteria or viral genotypes, with a total of 73 variations”, explains biologist Irene Araújo Maciel, technologist responsible for the analysis of the project at the Laboratorio do IOC.
The results obtained are sent to the University of Virginia, in the United States, where the test (called 'Tac Array Card') was developed and where scientists carry out the statistical analysis of the study.
The publication of the first research results was delayed by the Covid-19 pandemic, as health centers and laboratories needed to dedicate efforts to combating SARS-CoV-2. Currently, scientists are analyzing samples for 2020, but the goal is to perform real-time analyzes in the coming years.
“At this moment, we still have the reflection of the pandemic. But in the near future, we hope to do a real-time diagnosis. This will allow for a panoramic and geographical view of the dissemination of microorganisms on the five continents, to monitor outbreaks and compare what happens in different regions”, says José Paulo.
Diarrhea is one of the top five causes of death for children under five worldwide. Photograph: JaCZhou
According to the Ministry of Health, the classic form of rotavirus disease, especially in the age range of six months to two years, is characterized by an abrupt form of vomiting, most of the time there is diarrhea and the presence of high fever. Mild forms may occur in adults and forms that do not show symptoms in newborns and during the first four months of life.
Rotaviruses are transmitted by fecal-oral (stool-mouth) contact, person-to-person contact, and through contaminated water, food, and objects. There is a high concentration of the virus that causes the disease in the feces of infected children. Vomiting is also responsible for the spread of rotavirus and norovirus.
Part of the national vaccination schedule, the vaccine against rotavirus (VORH) is available free of charge in the Unified Health System (SUS). It is essential to be administered at 2 and 4 months of life for babies.
It is also necessary to follow basic care with personal and domestic hygiene, such as always washing your hands before and after using the bathroom, changing diapers, handling/preparing food, breastfeeding, handling dirty materials/objects, touching animals, in addition to washing and disinfect surfaces, utensils and equipment used in food preparation.
The Ministry of Health reinforces that maintaining breastfeeding increases children's resistance against various diseases, including diarrhea, and therefore reinforces the recommendation to avoid early weaning.
The non-profit reproduction of the text is allowed as long as the source is cited (Comunicação / Instituto Oswaldo Cruz)
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