Comment
9
10
11
Maida I, Ríos MJ, Pérez-Saleme L, et al. Profile of patients triply infected with HIV and the hepatitis B and C viruses in the HAART era. AIDS Res Hum Retroviruses 2008; 24: 679–83. Sollima S, Caramma I, Menzaghi B, et al. Chronic coinfection with hepatitis B and hepatitis C viruses in an Italian population of HIV-infected patients. J Acquir Immune Defic Syndr 2007; 44: 606–07. Martín-Carbonero L, Barreiro P, Jiménez-Galán G, et al. Clearance of hepatitis C virus in HIV-infected patients with multiple chronic viral epatiti. J Viral Hepat 2007; 14: 392–95.
12
13 14
Ladep NG, Agaba PA, Agbaji O, et al. Rates and impact of hepatitis on human immunodeficiency virus infection in a large African cohort. World J Gastroenterol 2013; 19: 1602–10. Soriano V, Grint D, D’Arminio-Monforte A, et al. Hepatitis delta in HIV-infected individuals in Europe. AIDS 2011; 25: 1987–92. Fernández-Montero JV, Vispo E, Barreiro P, et al. Hepatitis Delta is a major determinant of liver decompensation events and death in HIV-infected patients. Clin Infect Dis 2014; 58: 1549–53.
Global burden of listeriosis: the tip of the iceberg Listeriosis is a rare but severe infection. Three main invasive forms are described: septicaemia, neurolisteriosis, and maternal–neonatal infection. Listeriosis can also present as febrile gastroenteritis. Its foodborne origin was evidenced in the early 1980s.1 Since then, listeriosis has been implicated in about 80 recognised outbreaks, which led, mainly in high-income countries, to the implementation of national and supranational surveillance systems.2 This implementation of surveillance systems had a key role in the dissection of risk factors and control of outbreaks. However, an estimation of the worldwide burden of listeriosis was still missing. In The Lancet Infectious Diseases, Charline Maertens de Noordhout and colleagues3 report the results of a meta-analysis that estimates for the first time the global number of listeriosis cases, related deaths, and disability-adjusted life years (DALYs).3 An important limitation of this study is that data were available for only 52% of the world population. No information could be retrieved for 3·2 billion people mostly living in Africa, Latin America, and Asia. The authors estimated that 23 150 cases related to listeriosis occurred worldwide in 2010, resulting in 5463 deaths and 172 823 DALYs. Perinatal infections accounted for 20·7% of the cases. As acknowledged by the authors, these mean estimations were based on information from heterogeneous data collection systems with uneven exhaustiveness levels. The absence of data in some regions required the use of a multilevel random-effects model that extrapolates missing national incidences either from other countries of the same WHO subregion or from other WHO subregions. Regions with higher estimated incidence were also those with larger CIs. Such extrapolations are necessary but intrinsically provide poor estimates of the real burden of the disease, in view of important local variations in food www.thelancet.com/infection Vol 14 November 2014
contamination levels, population characteristics, surveillance methods, or health-care systems organisation and proficiency. One would indeed wish to take into account all these variables, which might affect the estimation of incidence and related mortality at the country level. Food contamination is affected by environmental variables such as climate and bacterial biodiversity. Although Listeria monocytogenes isolates seem to be evenly distributed,4 the distribution of putative hypervirulent clones is unknown and could be heterogeneous. Additionally, food production and preparation, storage conditions (refrigeration selectively allows growth of L monocytogenes), food distribution (local or large-scale), and dietary habits (consumer lifestyle, type, and portion of food consumed) all modify individual exposure to L monocytogenes and vary greatly from one WHO subregion to another, and also within a geographical region, in accordance with local resources and cultural discrepancies. Public health policies and their implementation, as well as demographic variables are major factors that should ideally be included in the equation estimating the incidence of listeriosis. For example, maternal– neonatal listeriosis incidence is correlated with fertility rate, whereas non-maternal-neonatal listeriosis mostly affects elderly people and patients receiving immunosuppressive therapies, as well as patients with comorbidities such as diabetes or obesity, both increasingly reported worldwide, but with geographical disparities. Furthermore, the poor availability of diagnostic resources and concomitant occurrence of highly prevalent diseases with similar symptoms might both lead to listeriosis under-reporting. Neonatal mortality is associated to infection in 28% of cases5 and ranges from five in 100 000 people in Europe to 31 in 100 000 in Africa. In regions with higher neonatal
Published Online September 16, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)70903-X See Articles page 1073
1027
Comment
infections and death rates, the pretest probability of perinatal listeriosis would be lower and so would be the performance of a listeriosis diagnostic procedure. Finally, access to health-care facilities and treatment availability obviously affects the outcome and infection-associated mortality. The implementation of a surveillance system is a prerequisite to measure L monocytogenes burden; but equally important are the methods of surveillance, which will determine data quality. In Europe, where most countries have set up national surveillance systems,2 disparities in data collection methods and exhaustiveness limit the relevance of global incidence estimation. Standardised case detection and reporting systems are mandatory to get a precise estimation of the burden of listeriosis, along with capture and recapture studies that assess the exhaustiveness of local reporting.6 In France, this approach has estimated the exhaustiveness of the mandatory reporting above 90%.7 In the past 30 years, important efforts have focused on the understanding of the pathophysiology of listeriosis. L monocytogenes has thereby become a model microorganism for the study of systemic bacterial infections and host responses to infection.8,9 Acquired risk factors for infection have been precisely identified,10 but important gaps remain. Antibiotic therapy based on combined ampicillin and gentamicin has not changed over the past three decades, in the absence of controlled studies.11 Non-maternal-neonatal listeriosis is still associated with 30% mortality, and pregnant women with listeriosis still experience fetal loss in at least 20% of recognised cases.12,13 Any large-scale intervention or prevention plan needs a complete and precise assessment of listeriosis global burden as a first step. A major achievement of this study is to provide
a first global estimation and to clearly delineate areas requiring urgent epidemiological assessment. *Alexandre Leclercq, Caroline Charlier, Marc Lecuit Institut Pasteur, WHO Collaborating Centre and French National Reference Centre for Listeria, Rue du Docteur Roux, 75724 Paris Cedex 15, Paris, France (AL, CC, ML); Institut Pasteur, Biology of Infection Unit, Paris, France (AL, CC, ML); Inserm U1117, Paris, France (AL, CC, ML); and Paris Descartes University, Sorbonne Paris Cité, Institut Imagine, Division of Infectious Diseases and Tropical Medicine, Necker-Pasteur Centre for Infectiology, Necker-Enfants Malades University Hospital, Paris, France (CC, ML) [email protected] We declare no competing interests. 1 2 3
4 5
6
7
8 9
10 11 12
13
Schlech WF 3rd, Lavigne PM, Bortolussi RA, et al. Epidemic listeriosis— evidence for transmission by food. N Engl J Med 1983; 308: 203–06. de Valk H, Jacquet C, Goulet V, et al. Surveillance of listeria infections in Europe. Euro Surveill 2005; 10: 251–55. Maertens de Noordhout C, Devleesschauwer B, Angulo FJ, et al. The global burden of listeriosis: a systematic review and meta-analysis. Lancet Infect Dis 2014; published online Sept 16. http://dx.doi.org/10.1016/ S1473-3099(14)70870-9. Chenal-Francisque V, Lopez J, Cantinelli T, et al. Worldwide distribution of major clones of Listeria monocytogenes. Emerg Infect Dis 2011; 17: 1110–12. WHO. Mortality and global health estimates: child mortality, 2013. http:// apps.who.int/gho/data/view.wrapper.CHILDCODv?lang=en (accessed July 31, 2014). Gibbons CL, Mangen MJ, Plass D, et al. Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods. BMC Public Health 2014; 14: 147. Goulet V, de Valk H, Pierre O, et al. Effect of prevention measures on incidence of human listeriosis, France, 19871997. Emerg Infect Dis 2001; 7: 983–89. Pamer EG. Immune responses to Listeria monocytogenes. Nat Rev Immunol 2004; 4: 812–23. Lecuit M, Vandormael-Pournin S, Lefort J, et al. A transgenic model for listeriosis: role of internalin in crossing the intestinal barrier. Science 2001; 292: 1722–25. Schuchat A, Swaminathan B, Broome CV. Epidemiology of human listeriosis. Clin Microbiol Rev 1991; 4: 169–83. Hof H, Nichterlein T, Kretschmar M. Management of listeriosis. Clin Microbiol Rev 1997; 10: 345–57. Mylonakis E, Hohmann EL, Calderwood SB. Central nervous system infection with Listeria monocytogenes. 33 years’ experience at a general hospital and review of 776 episodes from the literature. Medicine (Baltimore) 1998; 77: 313–36. Mylonakis E, Paliou M, Hohmann EL, et al. Listeriosis during pregnancy: a case series and review of 222 cases. Medicine (Baltimore) 2002; 81: 260–69.
Emergence of a hypervirulent neonatal pathogen See Articles page 1083
1028
Many prevention practices have been adopted to decrease the morbidity and mortality associated with infections in newborn babies caused by group B streptococcus. Despite these efforts, the bacterium remains a leading cause of bloodstream infections and meningitis worldwide. Group B streptococcus typically affects babies younger than 7 days (earlyonset) or infants up to 3 months of age (late-onset).
The primary prevention strategy involves prophylactic antibiotic treatment of women during childbirth. In the USA, intrapartum antibiotic prophylaxis contributed to a 65% reduction of early-onset disease, but had no effect on late-onset disease.1 Other studies have reported similar trends.2 However, a report by Vincent Bekker and colleagues in The Lancet Infectious Diseases,3 shows the opposite trend in the Netherlands over www.thelancet.com/infection Vol 14 November 2014
9
10
11
Maida I, Ríos MJ, Pérez-Saleme L, et al. Profile of patients triply infected with HIV and the hepatitis B and C viruses in the HAART era. AIDS Res Hum Retroviruses 2008; 24: 679–83. Sollima S, Caramma I, Menzaghi B, et al. Chronic coinfection with hepatitis B and hepatitis C viruses in an Italian population of HIV-infected patients. J Acquir Immune Defic Syndr 2007; 44: 606–07. Martín-Carbonero L, Barreiro P, Jiménez-Galán G, et al. Clearance of hepatitis C virus in HIV-infected patients with multiple chronic viral epatiti. J Viral Hepat 2007; 14: 392–95.
12
13 14
Ladep NG, Agaba PA, Agbaji O, et al. Rates and impact of hepatitis on human immunodeficiency virus infection in a large African cohort. World J Gastroenterol 2013; 19: 1602–10. Soriano V, Grint D, D’Arminio-Monforte A, et al. Hepatitis delta in HIV-infected individuals in Europe. AIDS 2011; 25: 1987–92. Fernández-Montero JV, Vispo E, Barreiro P, et al. Hepatitis Delta is a major determinant of liver decompensation events and death in HIV-infected patients. Clin Infect Dis 2014; 58: 1549–53.
Global burden of listeriosis: the tip of the iceberg Listeriosis is a rare but severe infection. Three main invasive forms are described: septicaemia, neurolisteriosis, and maternal–neonatal infection. Listeriosis can also present as febrile gastroenteritis. Its foodborne origin was evidenced in the early 1980s.1 Since then, listeriosis has been implicated in about 80 recognised outbreaks, which led, mainly in high-income countries, to the implementation of national and supranational surveillance systems.2 This implementation of surveillance systems had a key role in the dissection of risk factors and control of outbreaks. However, an estimation of the worldwide burden of listeriosis was still missing. In The Lancet Infectious Diseases, Charline Maertens de Noordhout and colleagues3 report the results of a meta-analysis that estimates for the first time the global number of listeriosis cases, related deaths, and disability-adjusted life years (DALYs).3 An important limitation of this study is that data were available for only 52% of the world population. No information could be retrieved for 3·2 billion people mostly living in Africa, Latin America, and Asia. The authors estimated that 23 150 cases related to listeriosis occurred worldwide in 2010, resulting in 5463 deaths and 172 823 DALYs. Perinatal infections accounted for 20·7% of the cases. As acknowledged by the authors, these mean estimations were based on information from heterogeneous data collection systems with uneven exhaustiveness levels. The absence of data in some regions required the use of a multilevel random-effects model that extrapolates missing national incidences either from other countries of the same WHO subregion or from other WHO subregions. Regions with higher estimated incidence were also those with larger CIs. Such extrapolations are necessary but intrinsically provide poor estimates of the real burden of the disease, in view of important local variations in food www.thelancet.com/infection Vol 14 November 2014
contamination levels, population characteristics, surveillance methods, or health-care systems organisation and proficiency. One would indeed wish to take into account all these variables, which might affect the estimation of incidence and related mortality at the country level. Food contamination is affected by environmental variables such as climate and bacterial biodiversity. Although Listeria monocytogenes isolates seem to be evenly distributed,4 the distribution of putative hypervirulent clones is unknown and could be heterogeneous. Additionally, food production and preparation, storage conditions (refrigeration selectively allows growth of L monocytogenes), food distribution (local or large-scale), and dietary habits (consumer lifestyle, type, and portion of food consumed) all modify individual exposure to L monocytogenes and vary greatly from one WHO subregion to another, and also within a geographical region, in accordance with local resources and cultural discrepancies. Public health policies and their implementation, as well as demographic variables are major factors that should ideally be included in the equation estimating the incidence of listeriosis. For example, maternal– neonatal listeriosis incidence is correlated with fertility rate, whereas non-maternal-neonatal listeriosis mostly affects elderly people and patients receiving immunosuppressive therapies, as well as patients with comorbidities such as diabetes or obesity, both increasingly reported worldwide, but with geographical disparities. Furthermore, the poor availability of diagnostic resources and concomitant occurrence of highly prevalent diseases with similar symptoms might both lead to listeriosis under-reporting. Neonatal mortality is associated to infection in 28% of cases5 and ranges from five in 100 000 people in Europe to 31 in 100 000 in Africa. In regions with higher neonatal
Published Online September 16, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)70903-X See Articles page 1073
1027
Comment
infections and death rates, the pretest probability of perinatal listeriosis would be lower and so would be the performance of a listeriosis diagnostic procedure. Finally, access to health-care facilities and treatment availability obviously affects the outcome and infection-associated mortality. The implementation of a surveillance system is a prerequisite to measure L monocytogenes burden; but equally important are the methods of surveillance, which will determine data quality. In Europe, where most countries have set up national surveillance systems,2 disparities in data collection methods and exhaustiveness limit the relevance of global incidence estimation. Standardised case detection and reporting systems are mandatory to get a precise estimation of the burden of listeriosis, along with capture and recapture studies that assess the exhaustiveness of local reporting.6 In France, this approach has estimated the exhaustiveness of the mandatory reporting above 90%.7 In the past 30 years, important efforts have focused on the understanding of the pathophysiology of listeriosis. L monocytogenes has thereby become a model microorganism for the study of systemic bacterial infections and host responses to infection.8,9 Acquired risk factors for infection have been precisely identified,10 but important gaps remain. Antibiotic therapy based on combined ampicillin and gentamicin has not changed over the past three decades, in the absence of controlled studies.11 Non-maternal-neonatal listeriosis is still associated with 30% mortality, and pregnant women with listeriosis still experience fetal loss in at least 20% of recognised cases.12,13 Any large-scale intervention or prevention plan needs a complete and precise assessment of listeriosis global burden as a first step. A major achievement of this study is to provide
a first global estimation and to clearly delineate areas requiring urgent epidemiological assessment. *Alexandre Leclercq, Caroline Charlier, Marc Lecuit Institut Pasteur, WHO Collaborating Centre and French National Reference Centre for Listeria, Rue du Docteur Roux, 75724 Paris Cedex 15, Paris, France (AL, CC, ML); Institut Pasteur, Biology of Infection Unit, Paris, France (AL, CC, ML); Inserm U1117, Paris, France (AL, CC, ML); and Paris Descartes University, Sorbonne Paris Cité, Institut Imagine, Division of Infectious Diseases and Tropical Medicine, Necker-Pasteur Centre for Infectiology, Necker-Enfants Malades University Hospital, Paris, France (CC, ML) [email protected] We declare no competing interests. 1 2 3
4 5
6
7
8 9
10 11 12
13
Schlech WF 3rd, Lavigne PM, Bortolussi RA, et al. Epidemic listeriosis— evidence for transmission by food. N Engl J Med 1983; 308: 203–06. de Valk H, Jacquet C, Goulet V, et al. Surveillance of listeria infections in Europe. Euro Surveill 2005; 10: 251–55. Maertens de Noordhout C, Devleesschauwer B, Angulo FJ, et al. The global burden of listeriosis: a systematic review and meta-analysis. Lancet Infect Dis 2014; published online Sept 16. http://dx.doi.org/10.1016/ S1473-3099(14)70870-9. Chenal-Francisque V, Lopez J, Cantinelli T, et al. Worldwide distribution of major clones of Listeria monocytogenes. Emerg Infect Dis 2011; 17: 1110–12. WHO. Mortality and global health estimates: child mortality, 2013. http:// apps.who.int/gho/data/view.wrapper.CHILDCODv?lang=en (accessed July 31, 2014). Gibbons CL, Mangen MJ, Plass D, et al. Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods. BMC Public Health 2014; 14: 147. Goulet V, de Valk H, Pierre O, et al. Effect of prevention measures on incidence of human listeriosis, France, 19871997. Emerg Infect Dis 2001; 7: 983–89. Pamer EG. Immune responses to Listeria monocytogenes. Nat Rev Immunol 2004; 4: 812–23. Lecuit M, Vandormael-Pournin S, Lefort J, et al. A transgenic model for listeriosis: role of internalin in crossing the intestinal barrier. Science 2001; 292: 1722–25. Schuchat A, Swaminathan B, Broome CV. Epidemiology of human listeriosis. Clin Microbiol Rev 1991; 4: 169–83. Hof H, Nichterlein T, Kretschmar M. Management of listeriosis. Clin Microbiol Rev 1997; 10: 345–57. Mylonakis E, Hohmann EL, Calderwood SB. Central nervous system infection with Listeria monocytogenes. 33 years’ experience at a general hospital and review of 776 episodes from the literature. Medicine (Baltimore) 1998; 77: 313–36. Mylonakis E, Paliou M, Hohmann EL, et al. Listeriosis during pregnancy: a case series and review of 222 cases. Medicine (Baltimore) 2002; 81: 260–69.
Emergence of a hypervirulent neonatal pathogen See Articles page 1083
1028
Many prevention practices have been adopted to decrease the morbidity and mortality associated with infections in newborn babies caused by group B streptococcus. Despite these efforts, the bacterium remains a leading cause of bloodstream infections and meningitis worldwide. Group B streptococcus typically affects babies younger than 7 days (earlyonset) or infants up to 3 months of age (late-onset).
The primary prevention strategy involves prophylactic antibiotic treatment of women during childbirth. In the USA, intrapartum antibiotic prophylaxis contributed to a 65% reduction of early-onset disease, but had no effect on late-onset disease.1 Other studies have reported similar trends.2 However, a report by Vincent Bekker and colleagues in The Lancet Infectious Diseases,3 shows the opposite trend in the Netherlands over www.thelancet.com/infection Vol 14 November 2014
