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1.
Int J Infect Dis ; 112: 136-143, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34517047

RESUMO

OBJECTIVES: Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population. METHODS: A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping. RESULTS: The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00-1.02). CONCLUSIONS: High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam.

2.
Clin Infect Dis ; 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34460902

RESUMO

INTRODUCTION: In Canada, first and second doses of mRNA vaccines against SARS-CoV-2 were uniquely spaced 16 weeks apart, but the duration of single-dose protection remains uncertain. We estimated one- and two-dose mRNA vaccine effectiveness (VE) among healthcare workers (HCWs) in Quebec, Canada including protection against varying outcome severity, variants of concern (VOC), and the stability of single-dose protection out to 16 weeks post-vaccination. METHODS: A test-negative design compared vaccination among SARS-CoV-2 test-positive and weekly-matched (10:1), randomly-sampled, test-negative HCWs using linked surveillance and immunization databases. Vaccine status was defined by one dose ≥14 days or two doses ≥7 days before illness onset or specimen collection. Adjusted VE was estimated by conditional logistic regression. RESULTS: Primary analysis included 5,316 cases and 53,160 controls. Single-dose VE was 70% (95%CI: 68-73) against SARS-CoV-2 infection, 73% (95%CI: 71-75) against COVID-19 illness and 97% (95%CI: 92-99) against associated hospitalization. Two-dose VE was 86% (95%CI: 81-90) and 93% (95%CI: 89-95), respectively, with no associated hospitalizations. VE was higher for non-VOC than VOC (73% Alpha) among single-dose (77%, 95%CI: 73-81 versus 63%, 95%CI: 57-67) but not two-dose recipients (87%, 95%CI: 57-96 versus 94%, 95%CI: 89-96). Across 16 weeks, no decline in single-dose VE was observed with appropriate stratification based upon prioritized vaccination determined by higher versus lower likelihood of direct patient contact. CONCLUSION: One mRNA vaccine dose provided substantial and sustained protection to HCWs extending at least four months post-vaccination. In circumstances of vaccine shortage, delaying the second dose may be a pertinent public health strategy to consider.

3.
Lancet Infect Dis ; 21(11): 1598-1610, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34245682

RESUMO

BACKGROUND: Introduction of human papillomavirus (HPV) vaccination has been slow in low-income and middle-income countries (LMICs) because of resource constraints and worldwide shortage of vaccine supplies. To help inform WHO recommendations, we modelled various HPV vaccination strategies to examine the optimal use of limited vaccine supplies and best allocation of scarce resources in LMICs in the context of the WHO global call to eliminate cervical cancer as a public health problem. METHODS: In this mathematical modelling analysis, we developed HPV-ADVISE LMIC, a transmission-dynamic model of HPV infection and diseases calibrated to four LMICs: India, Vietnam, Uganda, and Nigeria. For different vaccination strategies that encompassed use of a nine-valent vaccine (or a two-valent or four-valent vaccine assuming high cross-protection), we estimated three outcomes: reduction in the age-standardised rate of cervical cancer, number of doses needed to prevent one case of cervical cancer (NNV; as a measure of efficiency), and the incremental cost-effectiveness ratio (ICER; in 2017 international $ per disability-adjusted life-year [DALY] averted). We examined different vaccination strategies by varying the ages of routine HPV vaccination and number of age cohorts vaccinated, the population targeted, and the number of doses used. In our base case, we assumed 100% lifetime protection against HPV-16, HPV-18, HPV-31, HPV-33, HPV-45, HPV-52, and HPV-58; vaccination coverage of 80%; and a time horizon of 100 years. For the cost-effectiveness analysis, we used a 3% discount rate. Elimination of cervical cancer was defined as an age-standardised incidence of less than four cases per 100 000 woman-years. FINDINGS: We predicted that HPV vaccination could lead to cervical cancer elimination in Vietnam, India, and Nigeria, but not in Uganda. Compared with no vaccination, strategies that involved vaccinating girls aged 9-14 years with two doses were predicted to be the most efficient and cost-effective in all four LMICs. NNV ranged from 78 to 381 and ICER ranged from $28 per DALY averted to $1406 per DALY averted depending on the country. The most efficient and cost-effective strategies were routine vaccination of girls aged 14 years, with or without a later switch to routine vaccination of girls aged 9 years, and routine vaccination of girls aged 9 years with a 5-year extended interval between doses and a catch-up programme at age 14 years. Vaccinating boys (aged 9-14 years) or women aged 18 years or older resulted in substantially higher NNVs and ICERs. INTERPRETATION: We identified two strategies that could maximise efforts to prevent cervical cancer in LMICs given constraints on vaccine supplies and costs and that would allow a maximum of LMICs to introduce HPV vaccination. FUNDING: World Health Organization, Canadian Institute of Health Research, Fonds de recherche du Québec-Santé, Compute Canada, PATH, and The Bill & Melinda Gates Foundation. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

4.
Sex Transm Dis ; 48(4): 215-221, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33492093

RESUMO

BACKGROUND: We estimated the lifetime medical costs attributable to sexually transmitted infections (STIs) acquired in 2018, including sexually acquired human immunodeficiency virus (HIV). METHODS: We estimated the lifetime medical costs of infections acquired in 2018 in the United States for 8 STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus (HPV), hepatitis B, and HIV. We limited our analysis to lifetime medical costs incurred for treatment of STIs and for treatment of related sequelae; we did not include other costs, such as STI prevention. For each STI, except HPV, we calculated the lifetime medical cost by multiplying the estimated number of incident infections in 2018 by the estimated lifetime cost per infection. For HPV, we calculated the lifetime cost based on the projected lifetime incidence of health outcomes attributed to HPV infections acquired in 2018. Future costs were discounted at 3% annually. RESULTS: Incident STIs in 2018 imposed an estimated $15.9 billion (25th-75th percentile: $14.9-16.9 billion) in discounted, lifetime direct medical costs (2019 US dollars). Most of this cost was due to sexually acquired HIV ($13.7 billion) and HPV ($0.8 billion). STIs in women accounted for about one fourth of the cost of incident STIs when including HIV, but about three fourths when excluding HIV. STIs among 15- to 24-year-olds accounted for $4.2 billion (26%) of the cost of incident STIs. CONCLUSIONS: Incident STIs continue to impose a considerable lifetime medical cost burden in the United States. These results can inform health economic analyses to promote the use of cost-effective STI prevention interventions to reduce this burden.


Assuntos
Gonorreia , Infecções por HIV , Herpes Genital , Doenças Sexualmente Transmissíveis , Sífilis , Tricomoníase , Feminino , Infecções por HIV/epidemiologia , Herpes Genital/epidemiologia , Humanos , Doenças Sexualmente Transmissíveis/epidemiologia , Tricomoníase/epidemiologia , Estados Unidos/epidemiologia
5.
Sex Transm Dis ; 48(4): 273-277, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33492097

RESUMO

INTRODUCTION: Human papillomavirus (HPV) can cause anogenital warts and several types of cancer, including cervical cancers and precancers. We estimated the prevalence, incidence, and number of persons with prevalent and incident HPV infections in the United States in 2018. METHODS: Prevalence and incidence were estimated for infections with any HPV (any of 37 types detected using Linear Array) and disease-associated HPV, 2 types that cause anogenital warts plus 14 types detected by tests used for cervical cancer screening (HPV 6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68). We used the 2013-2016 National Health and Nutrition Examination Survey to estimate prevalence among 15- to 59-year-olds, overall and by sex. Incidences in 2018 were estimated per 10,000 persons using an individual-based transmission-dynamic type-specific model calibrated to US data. We estimated number of infected persons by applying prevalences and incidences to 2018 US population estimates. RESULTS: Prevalence of infection with any HPV was 40.0% overall, 41.8% in men, and 38.4% in women; prevalence of infection with disease-associated HPV was 24.2% in men and 19.9% in women. An estimated 23.4 and 19.2 million men and women had a disease-associated HPV type infection in 2018. Incidences of any and disease-associated HPV infection were 1222 and 672 per 10,000 persons; incidence of disease-associated HPV infection was 708 per 10,000 men and 636 per 10,000 women. An estimated 6.9 and 6.1 million men and women had an incident infection with a disease-associated HPV type in 2018. CONCLUSIONS: We document a high HPV burden of infection in the United States in 2018, with 42 million persons infected with disease-associated HPV and 13 million persons acquiring a new infection. Although most infections clear, some disease-associated HPV type infections progress to disease. The HPV burden highlights the need for continued monitoring of HPV-associated cancers, cervical cancer screening, and HPV vaccination to track and prevent disease.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero , Detecção Precoce de Câncer , Feminino , Humanos , Incidência , Masculino , Inquéritos Nutricionais , Infecções por Papillomavirus/epidemiologia , Prevalência , Estados Unidos/epidemiologia , Neoplasias do Colo do Útero/epidemiologia
6.
Sex Transm Dis ; 48(4): 278-284, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33492104

RESUMO

INTRODUCTION: We estimated the lifetime medical costs of diagnosed cases of diseases attributable to human papillomavirus (HPV) infections acquired in 2018. METHODS: We adapted an existing mathematical model of HPV transmission and associated diseases to estimate the lifetime number of diagnosed cases of disease (genital warts; cervical intraepithelial neoplasia; and cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers) attributable to HPV infections that were acquired in 2018. For each of these outcomes, we multiplied the estimated number of cases by the estimated lifetime medical cost per case obtained from previous studies. We estimated the costs of recurrent respiratory papillomatosis in a separate calculation. Future costs were discounted at 3% annually. RESULTS: The estimated discounted lifetime medical cost of diseases attributable to HPV infections acquired in 2018 among people aged 15 to 59 years was $774 million (in 2019 US dollars), of which approximately half was accounted for by infections in those aged 15 to 24 years. Human papillomavirus infections in women accounted for approximately 90% of the lifetime number of diagnosed cases of disease and 70% of the lifetime cost attributable to HPV infections acquired in 2018 among those aged 15 to 59 years. CONCLUSIONS: We estimated the lifetime medical costs of diseases attributable to HPV infections acquired in 2018 to be $774 million. This estimate is lower than previous estimates, likely due to the impact of HPV vaccination. The lifetime cost of disease attributable to incident HPV infections is expected to decrease further over time as HPV vaccination coverage increases.


Assuntos
Neoplasia Intraepitelial Cervical , Condiloma Acuminado , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero , Adolescente , Adulto , Condiloma Acuminado/epidemiologia , Análise Custo-Benefício , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/epidemiologia , Adulto Jovem
7.
Lancet ; 397(10272): 398-408, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516338

RESUMO

BACKGROUND: The past two decades have seen expansion of childhood vaccination programmes in low-income and middle-income countries (LMICs). We quantify the health impact of these programmes by estimating the deaths and disability-adjusted life-years (DALYs) averted by vaccination against ten pathogens in 98 LMICs between 2000 and 2030. METHODS: 16 independent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, and yellow fever. Using standardised demographic data and vaccine coverage, the impact of vaccination programmes was determined by comparing model estimates from a no-vaccination counterfactual scenario with those from a reported and projected vaccination scenario. We present deaths and DALYs averted between 2000 and 2030 by calendar year and by annual birth cohort. FINDINGS: We estimate that vaccination of the ten selected pathogens will have averted 69 million (95% credible interval 52-88) deaths between 2000 and 2030, of which 37 million (30-48) were averted between 2000 and 2019. From 2000 to 2019, this represents a 45% (36-58) reduction in deaths compared with the counterfactual scenario of no vaccination. Most of this impact is concentrated in a reduction in mortality among children younger than 5 years (57% reduction [52-66]), most notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 120 million (93-150) deaths will be averted by vaccination, of which 58 million (39-76) are due to measles vaccination and 38 million (25-52) are due to hepatitis B vaccination. We estimate that increases in vaccine coverage and introductions of additional vaccines will result in a 72% (59-81) reduction in lifetime mortality in the 2019 birth cohort. INTERPRETATION: Increases in vaccine coverage and the introduction of new vaccines into LMICs have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained. FUNDING: Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation.


Assuntos
Controle de Doenças Transmissíveis , Doenças Transmissíveis/mortalidade , Doenças Transmissíveis/virologia , Modelos Teóricos , Mortalidade/tendências , Anos de Vida Ajustados por Qualidade de Vida , Vacinação , Pré-Escolar , Controle de Doenças Transmissíveis/economia , Controle de Doenças Transmissíveis/estatística & dados numéricos , Doenças Transmissíveis/economia , Análise Custo-Benefício , Países em Desenvolvimento , Feminino , Saúde Global , Humanos , Programas de Imunização , Masculino , Vacinação/economia , Vacinação/estatística & dados numéricos
9.
Int J Infect Dis ; 102: 254-259, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33115683

RESUMO

OBJECTIVE: The North American coronavirus disease-2019 (COVID-19) epidemic exhibited distinct early trajectories. In Canada, Quebec had the highest COVID-19 burden and its earlier March school break, taking place two weeks before those in other provinces, could have shaped early transmission dynamics. METHODS: We combined a semi-mechanistic model of SARS-CoV-2 transmission with detailed surveillance data from Quebec and Ontario (initially accounting for 85% of Canadian cases) to explore the impact of case importation and timing of control measures on cumulative hospitalizations. RESULTS: A total of 1544 and 1150 cases among returning travelers were laboratory-confirmed in Quebec and Ontario, respectively (symptoms onset ≤03-25-2020). Hospitalizations could have been reduced by 55% (95% CrI: 51%-59%) if no cases had been imported after Quebec's March break. However, if Quebec had experienced Ontario's number of introductions, hospitalizations would have only been reduced by 12% (95% CrI: 8%-16%). Early public health measures mitigated the epidemic spread as a one-week delay could have resulted in twice as many hospitalizations (95% CrI: 1.7-2.1). CONCLUSION: Beyond introductions, factors such as public health preparedness, responses and capacity could play a role in explaining interprovincial differences. In a context where regions are considering lifting travel restrictions, coordinated strategies and proactive measures are to be considered.


Assuntos
COVID-19/transmissão , SARS-CoV-2 , Viagem , Adulto , Idoso , COVID-19/epidemiologia , Canadá/epidemiologia , Humanos , Pessoa de Meia-Idade , Modelos Teóricos , Saúde Pública
10.
Lancet Infect Dis ; 21(1): 116-126, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711690

RESUMO

BACKGROUND: Many immigrants are susceptible to varicella on arrival to Canada because of different transmission dynamics in their countries of origin and scarcity of vaccination. Universal childhood vaccination programmes decrease varicella incidence rates through herd immunity, but the accumulating number of susceptible adult immigrants could remain at risk for severe varicella. Our aim was to describe the epidemiology of varicella among immigrants and non-immigrants before and after childhood varicella vaccination. METHODS: We did a population-based, retrospective cohort study of all varicella cases in Quebec, Canada, diagnosed between 1996 and 2014 in administrative health databases linked to immigration data. Cases of varicella met diagnostic codes in the International Classification of Diseases, Ninth and Tenth Revision Canadian modifications. Cases with a co-occurring zoster diagnostic code and immigrants from Australia, New Zealand, the USA, and western European countries were excluded. Vaccination periods included pre-vaccination (1996-98), private vaccination (1999-2005), and public vaccination (2006-14). Incidence rate and comparative rate ratios were estimated using census data. FINDINGS: A total of 231 339 varicella cases diagnosed between Jan 1, 1996, and Dec 31, 2014, were linked to 1 115 696 immigrants who arrived between Jan 1, 1980, and Dec 31, 2014. 1444 herpes zoster cases and 1276 immigrants from Australia, western Europe, New Zealand, and the USA were excluded. Among 228 619 varicella cases, 13 315 (5·8%) occurred in immigrants. In pre-vaccination versus public vaccination periods, varicella incidence declined in immigrants by 87% (95% CI 86·6-87·9; 324·3 cases per 100 000 person-years to 40·9 cases per 100 000 person-years) and in non-immigrants by 93% (92·4-92·7; 484 cases per 100 000 person-years to 36 cases per 100 000 person-years). Mean age at diagnosis increased in both groups (15·1 vs 19·4 years in immigrants and 8·4 vs 12·0 years in non-immigrants). In the public vaccination period, immigrants younger than 50 years had higher varicella rates than non-immigrants, with relative risk ranging from 1·53 (95% CI 1·37-1·72) to 4·64 (3·90-5·53) with the highest risk in adolescents and young adults, and people from Latin America and the Caribbean (age-specific incidence rate ratio [aIRR]I-NI pre-vaccination 2·19 and post-vaccination aIRRI-NI6·07) and south Asia (aIRRI-NI pre-vaccination 3·41 and aIRRI-NI post-vaccination 4·46) and in childbearing women (15-40 years; IRRI-NI 2·48). INTERPRETATION: Immigrant adolescents, young adults, and women of childbearing age had higher age-standardised rates of varicella than non-immigrants, with increasing disparities following vaccine introduction. Immigrants younger than 50 years of age would benefit from targeted vaccination upon arrival to host countries. FUNDING: The Canadian Institutes of Health Research and The Department of Medicine, Jewish General Hospital, Montreal, QC, Canada.


Assuntos
Varicela/epidemiologia , Varicela/prevenção & controle , Emigrantes e Imigrantes/estatística & dados numéricos , Vigilância de Evento Sentinela , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Quebeque/epidemiologia , Estudos Retrospectivos , Adulto Jovem
11.
Prev Med ; 144: 106354, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33309871

RESUMO

The Director-General of the World Health Organization has called for global action towards elimination of cervical cancer as a public health problem. Cervical cancer is caused by human papillomavirus (HPV), an infectious agent with no non-human reservoir. One way to achieve this is through very high levels of vaccine coverage that could enable global eradication of vaccine-type HPV. Using the case study of India, we show that HPV eradication can meet all the Dahlem and Strüngmann criteria for feasibility of eradication. It can be achieved with 90% gender-neutral HPV vaccine coverage together with 95% coverage in high-risk groups such as female sex workers. Such a strategy would likely be cost-effective compared to no vaccination. Although it would be more costly in the short-term than achieving cervical cancer elimination alone, it would save costs in the long-term by removing or at least sharply reducing the need for preventive measures.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Profissionais do Sexo , Neoplasias do Colo do Útero , Análise Custo-Benefício , Estudos de Viabilidade , Feminino , Humanos , Índia , Papillomaviridae , Infecções por Papillomavirus/prevenção & controle , Saúde Pública , Neoplasias do Colo do Útero/prevenção & controle , Vacinação
13.
CMAJ ; 192(40): E1146-E1155, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-32907820

RESUMO

BACKGROUND: Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely passive, which impedes epidemic control. We defined active testing strategies for SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) for groups at increased risk of acquiring SARS-CoV-2 in all Canadian provinces. METHODS: We identified 5 groups who should be prioritized for active RT-PCR testing: contacts of people who are positive for SARS-CoV-2, and 4 at-risk populations - hospital employees, community health care workers and people in long-term care facilities, essential business employees, and schoolchildren and staff. We estimated costs, human resources and laboratory capacity required to test people in each group or to perform surveillance testing in random samples. RESULTS: During July 8-17, 2020, across all provinces in Canada, an average of 41 751 RT-PCR tests were performed daily; we estimated this required 5122 personnel and cost $2.4 million per day ($67.8 million per month). Systematic contact tracing and testing would increase personnel needs 1.2-fold and monthly costs to $78.9 million. Conducted over a month, testing all hospital employees would require 1823 additional personnel, costing $29.0 million; testing all community health care workers and persons in long-term care facilities would require 11 074 additional personnel and cost $124.8 million; and testing all essential employees would cost $321.7 million, requiring 25 965 added personnel. Testing the larger population within schools over 6 weeks would require 46 368 added personnel and cost $816.0 million. Interventions addressing inefficiencies, including saliva-based sampling and pooling samples, could reduce costs by 40% and personnel by 20%. Surveillance testing in population samples other than contacts would cost 5% of the cost of a universal approach to testing at-risk populations. INTERPRETATION: Active testing of groups at increased risk of acquiring SARS-CoV-2 appears feasible and would support the safe reopening of the economy and schools more broadly. This strategy also appears affordable compared with the $169.2 billion committed by the federal government as a response to the pandemic as of June 2020.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/economia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/economia , Programas de Rastreamento/economia , Pandemias/economia , Pneumonia Viral/diagnóstico , Pneumonia Viral/economia , COVID-19 , Teste para COVID-19 , Canadá , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Humanos , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Reação em Cadeia da Polimerase em Tempo Real/economia , Medição de Risco/economia , Fatores de Risco , SARS-CoV-2
14.
Lancet ; 395(10224): 575-590, 2020 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-32007141

RESUMO

BACKGROUND: The WHO Director-General has issued a call for action to eliminate cervical cancer as a public health problem. To help inform global efforts, we modelled potential human papillomavirus (HPV) vaccination and cervical screening scenarios in low-income and lower-middle-income countries (LMICs) to examine the feasibility and timing of elimination at different thresholds, and to estimate the number of cervical cancer cases averted on the path to elimination. METHODS: The WHO Cervical Cancer Elimination Modelling Consortium (CCEMC), which consists of three independent transmission-dynamic models identified by WHO according to predefined criteria, projected reductions in cervical cancer incidence over time in 78 LMICs for three standardised base-case scenarios: girls-only vaccination; girls-only vaccination and once-lifetime screening; and girls-only vaccination and twice-lifetime screening. Girls were vaccinated at age 9 years (with a catch-up to age 14 years), assuming 90% coverage and 100% lifetime protection against HPV types 16, 18, 31, 33, 45, 52, and 58. Cervical screening involved HPV testing once or twice per lifetime at ages 35 years and 45 years, with uptake increasing from 45% (2023) to 90% (2045 onwards). The elimination thresholds examined were an average age-standardised cervical cancer incidence of four or fewer cases per 100 000 women-years and ten or fewer cases per 100 000 women-years, and an 85% or greater reduction in incidence. Sensitivity analyses were done, varying vaccination and screening strategies and assumptions. We summarised results using the median (range) of model predictions. FINDINGS: Girls-only HPV vaccination was predicted to reduce the median age-standardised cervical cancer incidence in LMICs from 19·8 (range 19·4-19·8) to 2·1 (2·0-2·6) cases per 100 000 women-years over the next century (89·4% [86·2-90·1] reduction), and to avert 61·0 million (60·5-63·0) cases during this period. Adding twice-lifetime screening reduced the incidence to 0·7 (0·6-1·6) cases per 100 000 women-years (96·7% [91·3-96·7] reduction) and averted an extra 12·1 million (9·5-13·7) cases. Girls-only vaccination was predicted to result in elimination in 60% (58-65) of LMICs based on the threshold of four or fewer cases per 100 000 women-years, in 99% (89-100) of LMICs based on the threshold of ten or fewer cases per 100 000 women-years, and in 87% (37-99) of LMICs based on the 85% or greater reduction threshold. When adding twice-lifetime screening, 100% (71-100) of LMICs reached elimination for all three thresholds. In regions in which all countries can achieve cervical cancer elimination with girls-only vaccination, elimination could occur between 2059 and 2102, depending on the threshold and region. Introducing twice-lifetime screening accelerated elimination by 11-31 years. Long-term vaccine protection was required for elimination. INTERPRETATION: Predictions were consistent across our three models and suggest that high HPV vaccination coverage of girls can lead to cervical cancer elimination in most LMICs by the end of the century. Screening with high uptake will expedite reductions and will be necessary to eliminate cervical cancer in countries with the highest burden. FUNDING: WHO, UNDP, UN Population Fund, UNICEF-WHO-World Bank Special Program of Research, Development and Research Training in Human Reproduction, Canadian Institute of Health Research, Fonds de recherche du Québec-Santé, Compute Canada, National Health and Medical Research Council Australia Centre for Research Excellence in Cervical Cancer Control.


Assuntos
Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero/prevenção & controle , Adulto , Países em Desenvolvimento , Detecção Precoce de Câncer/métodos , Estudos de Viabilidade , Feminino , Humanos , Incidência , Renda , Programas de Rastreamento/métodos , Modelos Biológicos , Infecções por Papillomavirus/complicações , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Vacinação
15.
Lancet ; 395(10224): 591-603, 2020 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-32007142

RESUMO

BACKGROUND: WHO is developing a global strategy towards eliminating cervical cancer as a public health problem, which proposes an elimination threshold of four cases per 100 000 women and includes 2030 triple-intervention coverage targets for scale-up of human papillomavirus (HPV) vaccination to 90%, twice-lifetime cervical screening to 70%, and treatment of pre-invasive lesions and invasive cancer to 90%. We assessed the impact of achieving the 90-70-90 triple-intervention targets on cervical cancer mortality and deaths averted over the next century. We also assessed the potential for the elimination initiative to support target 3.4 of the UN Sustainable Development Goals (SDGs)-a one-third reduction in premature mortality from non-communicable diseases by 2030. METHODS: The WHO Cervical Cancer Elimination Modelling Consortium (CCEMC) involves three independent, dynamic models of HPV infection, cervical carcinogenesis, screening, and precancer and invasive cancer treatment. Reductions in age-standardised rates of cervical cancer mortality in 78 low-income and lower-middle-income countries (LMICs) were estimated for three core scenarios: girls-only vaccination at age 9 years with catch-up for girls aged 10-14 years; girls-only vaccination plus once-lifetime screening and cancer treatment scale-up; and girls-only vaccination plus twice-lifetime screening and cancer treatment scale-up. Vaccination was assumed to provide 100% lifetime protection against infections with HPV types 16, 18, 31, 33, 45, 52, and 58, and to scale up to 90% coverage in 2020. Cervical screening involved HPV testing at age 35 years, or at ages 35 years and 45 years, with scale-up to 45% coverage by 2023, 70% by 2030, and 90% by 2045, and we assumed that 50% of women with invasive cervical cancer would receive appropriate surgery, radiotherapy, and chemotherapy by 2023, which would increase to 90% by 2030. We summarised results using the median (range) of model predictions. FINDINGS: In 2020, the estimated cervical cancer mortality rate across all 78 LMICs was 13·2 (range 12·9-14·1) per 100 000 women. Compared to the status quo, by 2030, vaccination alone would have minimal impact on cervical cancer mortality, leading to a 0·1% (0·1-0·5) reduction, but additionally scaling up twice-lifetime screening and cancer treatment would reduce mortality by 34·2% (23·3-37·8), averting 300 000 (300 000-400 000) deaths by 2030 (with similar results for once-lifetime screening). By 2070, scaling up vaccination alone would reduce mortality by 61·7% (61·4-66·1), averting 4·8 million (4·1-4·8) deaths. By 2070, additionally scaling up screening and cancer treatment would reduce mortality by 88·9% (84·0-89·3), averting 13·3 million (13·1-13·6) deaths (with once-lifetime screening), or by 92·3% (88·4-93·0), averting 14·6 million (14·1-14·6) deaths (with twice-lifetime screening). By 2120, vaccination alone would reduce mortality by 89·5% (86·6-89·9), averting 45·8 million (44·7-46·4) deaths. By 2120, additionally scaling up screening and cancer treatment would reduce mortality by 97·9% (95·0-98·0), averting 60·8 million (60·2-61·2) deaths (with once-lifetime screening), or by 98·6% (96·5-98·6), averting 62·6 million (62·1-62·8) deaths (with twice-lifetime screening). With the WHO triple-intervention strategy, over the next 10 years, about half (48% [45-55]) of deaths averted would be in sub-Saharan Africa and almost a third (32% [29-34]) would be in South Asia; over the next 100 years, almost 90% of deaths averted would be in these regions. For premature deaths (age 30-69 years), the WHO triple-intervention strategy would result in rate reductions of 33·9% (24·4-37·9) by 2030, 96·2% (94·3-96·8) by 2070, and 98·6% (96·9-98·8) by 2120. INTERPRETATION: These findings emphasise the importance of acting immediately on three fronts to scale up vaccination, screening, and treatment for pre-invasive and invasive cervical cancer. In the next 10 years, a one-third reduction in the rate of premature mortality from cervical cancer in LMICs is possible, contributing to the realisation of the 2030 UN SDGs. Over the next century, successful implementation of the WHO elimination strategy would reduce cervical cancer mortality by almost 99% and save more than 62 million women's lives. FUNDING: WHO, UNDP, UN Population Fund, UNICEF-WHO-World Bank Special Program of Research, Development and Research Training in Human Reproduction, Germany Federal Ministry of Health, National Health and Medical Research Council Australia, Centre for Research Excellence in Cervical Cancer Control, Canadian Institute of Health Research, Compute Canada, and Fonds de recherche du Québec-Santé.


Assuntos
Neoplasias do Colo do Útero/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Países em Desenvolvimento , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Renda , Lactente , Recém-Nascido , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Modelos Biológicos , Mortalidade/tendências , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/virologia , Vacinação/métodos , Organização Mundial da Saúde , Adulto Jovem
16.
Lancet Glob Health ; 8(4): e536-e544, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32105613

RESUMO

BACKGROUND: The Papillomavirus Rapid Interface for Modelling and Economics (PRIME) has been used around the world to assess the health impact and cost-effectiveness of human papillomavirus (HPV) vaccination in girls. We updated PRIME with new data and methods for demography, disability weights, and cervical cancer burden, and generated revised estimates of the health impact of HPV vaccination at the global, regional, and national levels for 177 countries. METHODS: PRIME was updated with population demography of the UN World Population Prospects (UNWPP) 2019 revision, disability weights of the Global Burden of Disease (GBD) 2017 study, and cervical cancer burden from the Global Cancer Incidence, Mortality and Prevalence (GLOBOCAN) 2018 database. We estimated the lifetime health benefits for bivalent or quadrivalent and nonavalent vaccination of 9-year-old and 12-year-old girls at 90% coverage during 2020-29 in 177 countries. Health impact was presented in terms of cervical cancer cases, deaths, or disability-adjusted life-years (DALYs) averted per 1000 vaccinated girls in comparison with the counterfactual scenario of no vaccination, and the number of girls needed to be vaccinated to prevent a single case, death, or DALY. FINDINGS: In estimating the health impact of HPV vaccination of 9-year-old girls, the combined updates to demography, disability weights, cervical cancer burden estimates resulted in a 26% increase in the estimated number of cases averted, a 51% increase in deaths averted, and a 72% increase in DALYs averted per 1000 vaccinated girls for both the bivalent or quadrivalent and nonavalent vaccines, compared with previous estimates. With the updated model, the bivalent or quadrivalent HPV vaccine was estimated to avert 15 cases, 12 deaths, and 243 DALYs per 1000 vaccinated girls, and the nonavalent HPV vaccine was estimated to avert 19 cases, 14 deaths, and 306 DALYs per 1000 vaccinated girls. The health benefits of vaccination of 12-year-old girls were estimated to be similar but slightly decreased in comparison with vaccination of 9-year-old girls. INTERPRETATION: HPV vaccination provides greater health benefits and is more cost-effective than was previously estimated. The demography update, which incorporates population aging, has the largest effect on the health impact estimates. The WHO African region is expected to gain the greatest health benefits and should be prioritised for HPV vaccination. FUNDING: Gavi, the Vaccine Alliance; Bill & Melinda Gates Foundation.


Assuntos
Saúde Global/estatística & dados numéricos , Vacinas contra Papillomavirus/administração & dosagem , Neoplasias do Colo do Útero/prevenção & controle , Criança , Demografia/estatística & dados numéricos , Pessoas com Deficiência/estatística & dados numéricos , Feminino , Humanos , Modelos Teóricos , Neoplasias do Colo do Útero/epidemiologia
17.
PeerJ ; 8: e8516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32095350

RESUMO

Introduction: Human papillomavirus (HPV) is the most common sexually transmitted infection (STI) worldwide. Despite recommendations for HPV vaccination of young women from health authorities, parental concerns were raised whether vaccination could induce unsafe sexual behaviour in young women. Therefore, the primary aim of this study was to investigate if HPV vaccination in healthcare seeking adult women in Luxembourg was associated with unsafe sexual behaviour. Methods: Seven hundred twenty-nine women (mean age = 22.5; range 18-43 years) were recruited either at Luxembourg family planning centres or at private gynaecology practices. All participants completed a questionnaire on vaccination status and sexual behaviour. Poisson and logistic regressions were used to study the association between sexual behaviour and vaccination status (N = 538). Both models were restricted to women younger than 26 years, since the first cohort being vaccinated would be 25 years old at the time of sampling. Assortativity of sexual mixing by age was also assessed for further transmission modelling for women <30 years reporting age of last/current sexual partner (N = 649). Women older than 29 years were excluded from the assortativity analysis due to restricted sample size. Results: In total, 386/538 (71.8%) of participants reported receiving HPV vaccine. Vaccination uptake significantly varied by nationality and was higher in Portuguese 112/142 (78.9%) and in Luxembourgish 224/313(71.6%) residents, and lower in residents of other nationalities 50/83 (60.2%) (p = 0.011). HPV vaccination was not associated with unsafe sexual behaviour such as shorter relationship duration with current or last sexual partner (odds ratio (OR) = 1.05, 95% CI [0.94-1.16]), younger age of sexual debut (OR = 1.00, 95% CI [0.88-1.14]), increased number of lifetime sexual partners (OR = 0.95, 95% CI [0.87-1.03), higher age difference with sexual partner (OR = 1.01, 95% CI [0.95-1.08]), condom use (OR = 0.97, 95% CI [0.60-1.56]), nor with other factors like smoking (OR = 0.73, 95% CI [0.47-1.15]) and nationality. HPV vaccination was only associated with younger age (OR = 0.84, 95% CI [0.75-0.94]). Relationship duration, age of sexual debut, age difference with sexual partner, smoking, age and non-Portuguese foreign nationality were predictors of number of lifetime sexual partners. Assortativity analysis revealed that young women chose sexual partners who were 2.3 years older on average. Conclusions: Our study found no association between unsafe sexual behaviour and HPV vaccination.

19.
Ann Intern Med ; 172(1): 22-29, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31816629

RESUMO

Background: In the United States, the routine age for human papillomavirus (HPV) vaccination is 11 to 12 years, with catch-up vaccination through age 26 years for women and 21 years for men. U.S. vaccination policy on use of the 9-valent HPV vaccine in adult women and men is being reviewed. Objective: To evaluate the added population-level effectiveness and cost-effectiveness of extending the current U.S. HPV vaccination program to women aged 27 to 45 years and men aged 22 to 45 years. Design: The analysis used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), an individual-based transmission dynamic model of HPV infection and associated diseases, calibrated to age-specific U.S. data. Data Sources: Published data. Target Population: Women aged 27 to 45 years and men aged 22 to 45 years in the United States. Time Horizon: 100 years. Perspective: Health care sector. Intervention: 9-valent HPV vaccination. Outcome Measures: HPV-associated outcomes prevented and cost-effectiveness ratios. Results of Base-Case Analysis: The model predicts that the current U.S. HPV vaccination program will reduce the number of diagnoses of anogenital warts and cervical intraepithelial neoplasia of grade 2 or 3 and cases of cervical cancer and noncervical HPV-associated cancer by 82%, 80%, 59%, and 39%, respectively, over 100 years and is cost saving (vs. no vaccination). In contrast, extending vaccination to women and men aged 45 years is predicted to reduce these outcomes by an additional 0.4, 0.4, 0.2, and 0.2 percentage points, respectively. Vaccinating women and men up to age 30, 40, and 45 years is predicted to cost $830 000, $1 843 000, and $1 471 000, respectively, per quality-adjusted life-year gained (vs. current vaccination). Results of Sensitivity Analysis: Results were most sensitive to assumptions about natural immunity and progression rates after infection, historical vaccination coverage, and vaccine efficacy. Limitation: Uncertainty about the proportion of HPV-associated disease due to infections after age 26 years and about the level of herd effects from the current HPV vaccination program. Conclusion: The current HPV vaccination program is predicted to be cost saving. Extending vaccination to older ages is predicted to produce small additional health benefits and result in substantially higher incremental cost-effectiveness ratios than the current recommendation. Primary Funding Source: Centers for Disease Control and Prevention.


Assuntos
Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Adulto , Fatores Etários , Análise Custo-Benefício , Feminino , Custos de Cuidados de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/economia , Vacinas contra Papillomavirus/economia , Resultado do Tratamento , Estados Unidos/epidemiologia , Adulto Jovem
20.
Vaccine ; 38(6): 1302-1314, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31870572

RESUMO

OBJECTIVES: This study aimed to systematically review the literature on the efficacy and immunogenicity of single-dose HPV vaccination compared to no vaccination or multi-dose schedules among vaccine trial participants. METHODS: Medline, EMBASE, Global Health Database and Cochrane Central Register of Controlled Trials were searched for publications and conference abstracts (dated January 1999-August 2018) using MeSH and non-MeSH terms for human papillomavirus AND vaccines AND (immunogenicity OR efficacy/effectiveness) AND dosage. Search results were screened against pre-specified eligibility criteria. Data were extracted from included articles, and a narrative synthesis conducted on efficacy against HPV16/18 infection and humoral immunogenicity. RESULTS: Seven of 6,523 unique records identified were included in the review. Six were nested observational studies of participants randomised to receive two or three doses in three large HPV vaccine trials, in which some participants did not complete their allocated schedules. One small pilot study prospectively allocated participants to receive one or no vaccine dose. Frequency of HPV16/18 infection was low (e.g. <1% for 12-month-persistent infection) in all vaccinated participants up to seven years post vaccination and did not significantly differ by number of doses (p > 0.05 in all cases). Frequency of infection was significantly lower in one-dose recipients compared to unvaccinated controls (p < 0.01 for all infection endpoints in each study). HPV16/18 seropositivity rates were high in all HPV vaccine recipients (100% in three of four studies reporting this endpoint), though antibody levels were lower with one compared to two or three doses. CONCLUSIONS: This review supports the premise that one HPV vaccine dose may be as effective in preventing HPV infection as multi-dose schedules in healthy young women. However, it also highlights the paucity of available evidence from purpose-designed, prospectively-randomised trials. Results from ongoing clinical trials assessing the efficacy and immunogenicity of single-dose HPV vaccination compared to currently-recommended schedules are awaited.


Assuntos
Imunogenicidade da Vacina , Infecções por Papillomavirus , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/imunologia , Vacinação/métodos , Feminino , Papillomavirus Humano 16/imunologia , Papillomavirus Humano 18/imunologia , Humanos , Imunidade Humoral , Esquemas de Imunização , Estudos Observacionais como Assunto , Infecções por Papillomavirus/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto
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