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Russian health-care workers run high risk of latent tuberculosis
Newsdesk
HPV vaccine mandate stirs controversy in USA As TLID goes to press, US health officials continue to debate the requirement that young girls be inoculated against human papillomavirus (HPV). The vaccine, Gardasil, has been shown to be 100% effective against HPV strains 16 and 18, which together cause 70% of cervical cancers and 90% of genital warts. “The vaccine is a marvel and seems to be extremely safe”, said Gilbert Ross, American Council on Science and Health, a public-health advocacy organisation based in New York City. “If it is given to enough young girls, some degree of community (or herd) immunity might develop to protect even those who are not vaccinated.” Indeed, the vaccine’s efficacy is one factor that does not seem to be in contention. But, Ross notes, the effort to require vaccination before girls enter the sixth grade (around age 12) has created strange bedfellows among
opponents. These include groups who generally distrust drug company motives, advocates who oppose the vaccine’s high cost (US$400 for the three-injection course), conservatives who say mandatory vaccination will encourage sexual activity among young girls, and anti-vaccine activists who are concerned about side-effects. “The idea that vaccination will encourage sexual activity is ridiculous. We heard the same argument about condom distribution and it has been shown time and again scientifically that this is not the case. This comes mainly from parents who are uncomfortable discussing the subject”, asserted Ross. On June 29, 2006, the Advisory Committee on Immunization Practices at the US Centers for Disease Control and Prevention (CDC) recommended that 11–12-year-old girls receive the
vaccine. But individual states decide which vaccines are required for school entry, and state requirements differ. Some bills calling for compulsory HPV vaccination have “opt out” provisions that allow parents to choose not to have their daughters vaccinated, noted Martin Myers (National Network for Immunization Information, Galveston, TX, USA). But advocates are concerned “that if you allow people to opt out of one vaccine, they will opt out of other vaccines that are due at the same time” (New York Times; Feb 17, 2007). Once the mandate on girls is sorted out, health officials might well have to move on to the issue of vaccinating boys. According to the CDC, if studies now underway show efficacy, “this vaccine may be recommended for boys/men, as well”.
Marilynn Larkin
For more information on the HPV vaccine see http://www. cdc.gov/std/hpv/STDFact-HPVvaccine.htm
For more information on the recommendations of the CDC’s Advisory Committee on Immunization Practices see http://www.cdc.gov/std/hpv/ STDFact-HPV-vaccine-hcp.htm
Russian health-care workers run high risk of latent tuberculosis A cross-sectional study of the prevalence of latent tuberculosis infection in Russian health-care workers reveals a gradient of latent tuberculosis infection proportional to exposure. Medical students have low rates of latent tuberculosis infection but this rises in primary health-care providers, doctors, and tuberculosis laboratory workers. “Our findings should help to inform occupational health policy in Russia and elsewhere”, said lead author Francis Drobniewski (University of London, London, UK). The study used an interferon-γ assay, a new blood-based test for tuberculosis infection. Latent tuberculosis infection was seen in 40·8% of staff and was significantly higher in doctors and nurses (39·1%) than in students (8·7%; relative risk 4·5; 95% CI 3·1–6·5). “The high rates of infection seen in this study are not likely to be false-positive results as a result of previous BCG vaccinations”, said Madhukar Pai (McGill University, http://infection.thelancet.com Vol 7 April 2007
Montreal, Canada). Repeated BCG vaccinations and tuberculin skin tests are common in Russia. “In such settings, the conventional tuberculin skin test for tuberculosis infection will perform poorly but the interferon-γ assays are highly specific and not affected by previous BCG vaccinations”, he added. Tony Harries (Ministry of Health, Lilongwe, Malawi) stresses that BCG vaccination does not prevent vaccinated people from becoming infected with Mycobacterium tuberculosis. “In children who do get infected, BCG prevents the development of serious disease, but there is no evidence that repeated vaccinations later in life have any beneficial effect”, he said. With respect to prophylaxis, healthcare workers with latent infection often receive preventive therapy with isoniazid for 6–9 months in developed countries such as the USA and Canada. This reduces the risk of progression from latent infection to active tuberculosis.
However, said Pai, despite the high burden of tuberculosis in health-care workers in low-income countries, such preventive therapy interventions are rarely used; the focus is mainly on identification and treatment of active, not latent, tuberculosis. Harries added: “If the infection involves isoniazidresistant tuberculosis bacilli, the drug is likely not to work”. Harries and Pai agree that the results suggest that tuberculosis infection control measures need to be implemented urgently in Russia and other high-burden countries, and there are important global implications. “The emergence of extensively drug-resistant tuberculosis has created interest in improving tuberulosis infection control activities”, said Pai. The US Centers for Disease Control and Prevention and WHO have published guidelines on how this might be achieved.
For more information on latent tuberculosis infection in Russian health-care workers see PLoS Med 2007; 4: e55; DOI:10.1371/journal. pmed.0040055
Kathryn Senior 251
HPV vaccine mandate stirs controversy in USA As TLID goes to press, US health officials continue to debate the requirement that young girls be inoculated against human papillomavirus (HPV). The vaccine, Gardasil, has been shown to be 100% effective against HPV strains 16 and 18, which together cause 70% of cervical cancers and 90% of genital warts. “The vaccine is a marvel and seems to be extremely safe”, said Gilbert Ross, American Council on Science and Health, a public-health advocacy organisation based in New York City. “If it is given to enough young girls, some degree of community (or herd) immunity might develop to protect even those who are not vaccinated.” Indeed, the vaccine’s efficacy is one factor that does not seem to be in contention. But, Ross notes, the effort to require vaccination before girls enter the sixth grade (around age 12) has created strange bedfellows among
opponents. These include groups who generally distrust drug company motives, advocates who oppose the vaccine’s high cost (US$400 for the three-injection course), conservatives who say mandatory vaccination will encourage sexual activity among young girls, and anti-vaccine activists who are concerned about side-effects. “The idea that vaccination will encourage sexual activity is ridiculous. We heard the same argument about condom distribution and it has been shown time and again scientifically that this is not the case. This comes mainly from parents who are uncomfortable discussing the subject”, asserted Ross. On June 29, 2006, the Advisory Committee on Immunization Practices at the US Centers for Disease Control and Prevention (CDC) recommended that 11–12-year-old girls receive the
vaccine. But individual states decide which vaccines are required for school entry, and state requirements differ. Some bills calling for compulsory HPV vaccination have “opt out” provisions that allow parents to choose not to have their daughters vaccinated, noted Martin Myers (National Network for Immunization Information, Galveston, TX, USA). But advocates are concerned “that if you allow people to opt out of one vaccine, they will opt out of other vaccines that are due at the same time” (New York Times; Feb 17, 2007). Once the mandate on girls is sorted out, health officials might well have to move on to the issue of vaccinating boys. According to the CDC, if studies now underway show efficacy, “this vaccine may be recommended for boys/men, as well”.
Marilynn Larkin
For more information on the HPV vaccine see http://www. cdc.gov/std/hpv/STDFact-HPVvaccine.htm
For more information on the recommendations of the CDC’s Advisory Committee on Immunization Practices see http://www.cdc.gov/std/hpv/ STDFact-HPV-vaccine-hcp.htm
Russian health-care workers run high risk of latent tuberculosis A cross-sectional study of the prevalence of latent tuberculosis infection in Russian health-care workers reveals a gradient of latent tuberculosis infection proportional to exposure. Medical students have low rates of latent tuberculosis infection but this rises in primary health-care providers, doctors, and tuberculosis laboratory workers. “Our findings should help to inform occupational health policy in Russia and elsewhere”, said lead author Francis Drobniewski (University of London, London, UK). The study used an interferon-γ assay, a new blood-based test for tuberculosis infection. Latent tuberculosis infection was seen in 40·8% of staff and was significantly higher in doctors and nurses (39·1%) than in students (8·7%; relative risk 4·5; 95% CI 3·1–6·5). “The high rates of infection seen in this study are not likely to be false-positive results as a result of previous BCG vaccinations”, said Madhukar Pai (McGill University, http://infection.thelancet.com Vol 7 April 2007
Montreal, Canada). Repeated BCG vaccinations and tuberculin skin tests are common in Russia. “In such settings, the conventional tuberculin skin test for tuberculosis infection will perform poorly but the interferon-γ assays are highly specific and not affected by previous BCG vaccinations”, he added. Tony Harries (Ministry of Health, Lilongwe, Malawi) stresses that BCG vaccination does not prevent vaccinated people from becoming infected with Mycobacterium tuberculosis. “In children who do get infected, BCG prevents the development of serious disease, but there is no evidence that repeated vaccinations later in life have any beneficial effect”, he said. With respect to prophylaxis, healthcare workers with latent infection often receive preventive therapy with isoniazid for 6–9 months in developed countries such as the USA and Canada. This reduces the risk of progression from latent infection to active tuberculosis.
However, said Pai, despite the high burden of tuberculosis in health-care workers in low-income countries, such preventive therapy interventions are rarely used; the focus is mainly on identification and treatment of active, not latent, tuberculosis. Harries added: “If the infection involves isoniazidresistant tuberculosis bacilli, the drug is likely not to work”. Harries and Pai agree that the results suggest that tuberculosis infection control measures need to be implemented urgently in Russia and other high-burden countries, and there are important global implications. “The emergence of extensively drug-resistant tuberculosis has created interest in improving tuberulosis infection control activities”, said Pai. The US Centers for Disease Control and Prevention and WHO have published guidelines on how this might be achieved.
For more information on latent tuberculosis infection in Russian health-care workers see PLoS Med 2007; 4: e55; DOI:10.1371/journal. pmed.0040055
Kathryn Senior 251