Impact of vaccination against severe COVID-19 in the French population aged 50 years and above: a retrospective population-based study.

BACKGROUND: Given the widespread implementation of COVID-19 vaccination to mitigate the pandemic from the end of 2020, it is important to retrospectively evaluate its impact, in particular by quantifying the number of severe outcomes prevented through vaccination. METHODS: We estimated the number of hospitalizations, intensive care unit (ICU) admissions and deaths directly averted by vaccination in France, in people aged ≥ 50 years, from December 2020 to March 2022, based on (1) the number of observed events, (2) vaccination coverage, and (3) vaccine effectiveness. We accounted for the effect of primary vaccination and the first booster dose, the circulating variants, the age groups, and the waning of vaccine-induced protection over time. RESULTS: An estimated 480,150 (95% CI: 260,072-582,516) hospitalizations, 132,156 (50,409-157,767) ICU admissions and 125,376 (53,792-152,037) deaths were directly averted by vaccination in people aged ≥ 50 years, which corresponds to a reduction of 63.2% (48.2-67.6), 68.7% (45.6-72.4) and 62.7% (41.9-67.1) respectively, compared to what would have been expected without vaccination over the study period. An estimated 5852 (2285-6853) deaths were directly averted among the 50-59 years old, 16,837 (6568-19,473) among the 60-69 years old, 32,136 (13,651-36,758) among the 70-79 years old and 70,551 (31,288-88,953) among the ≥ 80 years old. CONCLUSIONS: The vaccination campaign in France considerably reduced COVID-19 morbidity and mortality, as well as stress on the healthcare system.

Monitoring the reproductive number of COVID-19 in France: Comparative estimates from three datasets.

BACKGROUND: The effective reproduction number (Rt) quantifies the average number of secondary cases caused by one person with an infectious disease. Near-real-time monitoring of Rt during an outbreak is a major indicator used to monitor changes in disease transmission and assess the effectiveness of interventions. The estimation of Rt usually requires the identification of infected cases in the population, which can prove challenging with the available data, especially when asymptomatic people or with mild symptoms are not usually screened. The purpose of this study was to perform sensitivity analysis of Rt estimates for COVID-19 surveillance in France based on three data sources with different sensitivities and specificities for identifying infected cases. METHODS: We applied a statistical method developed by Cori et al. to estimate Rt using (1) confirmed cases identified from positive virological tests in the population, (2) suspected cases recorded by a national network of emergency departments, and (3) COVID-19 hospital admissions recorded by a national administrative system to manage hospital organization. RESULTS: Rt estimates in France from May 27, 2020, to August 12, 2022, showed similar temporal trends regardless of the dataset. Estimates based on the daily number of confirmed cases provided an earlier signal than the two other sources, with an average lag of 3 and 6 days for estimates based on emergency department visits and hospital admissions, respectively. CONCLUSION: The COVID-19 experience confirmed that monitoring temporal changes in Rt was a key indicator to help the public health authorities control the outbreak in real time. However, gaining access to data on all infected people in the population in order to estimate Rt is not straightforward in practice. As this analysis has shown, the opportunity to use more readily available data to estimate Rt trends, provided that it is highly correlated with the spread of infection, provides a practical solution for monitoring the COVID-19 pandemic and indeed any other epidemic.

Direct impact of COVID-19 by estimating disability-adjusted life years at national level in France in 2020.

BACKGROUND: The World Health Organization declared a pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), on March 11, 2020. The standardized approach of disability-adjusted life years (DALYs) allows for quantifying the combined impact of morbidity and mortality of diseases and injuries. The main objective of this study was to estimate the direct impact of COVID-19 in France in 2020, using DALYs to combine the population health impact of infection fatalities, acute symptomatic infections and their post-acute consequences, in 28 days (baseline) up to 140 days, following the initial infection. METHODS: National mortality, COVID-19 screening, and hospital admission data were used to calculate DALYs based on the European Burden of Disease Network consensus disease model. Scenario analyses were performed by varying the number of symptomatic cases and duration of symptoms up to a maximum of 140 days, defining COVID-19 deaths using the underlying, and associated, cause of death. RESULTS: In 2020, the estimated DALYs due to COVID-19 in France were 990 710 (1472 per 100 000), with 99% of burden due to mortality (982 531 years of life lost, YLL) and 1% due to morbidity (8179 years lived with disability, YLD), following the initial infection. The contribution of YLD reached 375%, assuming the duration of 140 days of post-acute consequences of COVID-19. Post-acute consequences contributed to 49% of the total morbidity burden. The contribution of YLD due to acute symptomatic infections among people younger than 70 years was higher (67%) than among people aged 70 years and above (33%). YLL among people aged 70 years and above, contributed to 74% of the total YLL. CONCLUSIONS: COVID-19 had a substantial impact on population health in France in 2020. The majority of population health loss was due to mortality. Men had higher population health loss due to COVID-19 than women. Post-acute consequences of COVID-19 had a large contribution to the YLD component of the disease burden, even when we assume the shortest duration of 28 days, long COVID burden is large. Further research is recommended to assess the impact of health inequalities associated with these estimates.

Risk of a blood donation contaminated with hepatitis E virus entering the blood supply before the implementation of universal RNA screening in France.

BACKGROUND AND OBJECTIVES: The risk of a blood donation contaminated with hepatitis E virus (HEV) entering the blood supply before introducing universal HEV-RNA screening in France was estimated to assess the benefit of such a measure. MATERIALS AND METHODS: The results of selective HEV nucleic acid testing (HEV-NAT) performed in mini pool of six plasma donations between 2018 and 2020 were extrapolated to the whole blood donor (BD) population after adjustment on three variables: regional establishment, sex and age group. RESULTS: Among the 246,285 plasma donations collected from 172,635 BDs tested for HEV-RNA, 248 (10.1/10,000) were positive. The extrapolation to all BDs led to an estimated rate of 5.9/10,000 donations (95% confidence interval [CI]: 4.5-7.4) which would be positive to HEV-RNA and a prevalence of 9.9/10,000 BDs (95% CI: 7.5-12.3). This prevalence was 4.4 times higher in males than females (16.8/10,000 vs. 3.8/10,000, p < 10-4 ). The highest prevalence was observed in males in the 30-39 age group (20.5/10,000) and the lowest in females in the 50-70 age group (2.8/10,000). CONCLUSION: The risk of an HEV-RNA-positive donation entering the blood supply was estimated at 1 in 1682 donations. This risk does not translate directly to the risk of HEV transfusion transmission, which mainly depends on the total number of viral particles in the transfused blood component and the sensitivity of NAT.

Bayesian multi-response nonlinear mixed-effect model: application of two recent HIV infection biomarkers.

Since the discovery of the human immunodeficiency virus (HIV) 35 years ago, the epidemic is still ongoing in France. To monitor the dynamics of HIV transmission and assess the impact of prevention campaigns, the main indicator is the incidence. One method to estimate the HIV incidence is based on biomarker values at diagnosis and their dynamics over time. Estimating the HIV incidence from biomarkers first requires modeling their dynamics since infection using external longitudinal data. The objective of the work presented here is to estimate the joint dynamics of two biomarkers from the PRIMO cohort. We thus jointly modeled the dynamics of two biomarkers (TM and V3) using a multi-response nonlinear mixed-effect model. The parameters were estimated using Bayesian Hamiltonian Monte Carlo inference. This procedure was first applied to the real data of the PRIMO cohort. In a simulation study, we then evaluated the performance of the Bayesian procedure for estimating the parameters of multi-response nonlinear mixed-effect models.

A multi-state Markov model using notification data to estimate HIV incidence, number of undiagnosed individuals living with HIV, and delay between infection and diagnosis: Illustration in France, 2008-2018.

Thirty-five years since the discovery of the human immunodeficiency virus (HIV), the epidemic is still ongoing in France. To guide HIV prevention strategies and monitor their impact, it is essential to understand the dynamics of the HIV epidemic. The indicator for reporting the progress of new infections is the HIV incidence. Given that HIV is mainly transmitted by undiagnosed individuals and that earlier treatment leads to less HIV transmission, it is essential to know the number of infected people unaware of their HIV-positive status as well as the time between infection and diagnosis. Our approach is based on a non-homogeneous multi-state Markov model describing the progression of the HIV disease. We propose a penalized likelihood approach to estimate the HIV incidence curve as well as the diagnosis rates. The HIV incidence curve was approximated using cubic M-splines, while an approximation of the cross-validation criterion was used to estimate the smoothing parameter. In a simulation study, we evaluate the performance of the model for reconstructing the HIV incidence curve and diagnosis rates. The method is illustrated in the population of men who have sex with men using HIV surveillance data collected by the French Institute for Public Health Surveillance since 2004.

Discriminating Between Premigration and Postmigration HIV Acquisition Using Surveillance Data.

BACKGROUND: Migrant populations are overrepresented among persons diagnosed with HIV in the European Union and the European Economic Area. Understanding the timing of HIV acquisition (premigration or postmigration) is crucial for developing public health interventions and for producing reliable estimates of HIV incidence and the number of people living with undiagnosed HIV infection. We summarize a recently proposed method for determining the timing of HIV acquisition and apply it to both real and simulated data. METHODS: The considered method combines estimates from a mixed model, applied to data from a large seroconverters' cohort, with biomarker measurements and individual characteristics to derive probabilities of premigration HIV acquisition within a Bayesian framework. The method is applied to a subset of data from the European Surveillance System (TESSy) and simulated data. FINDINGS: Simulation study results showed good performance with the probabilities of correctly classifying a premigration case or a postmigration case being 87.4% and 80.4%, respectively. Applying the method to TESSy data, we estimated the proportions of migrants who acquired HIV in the destination country were 31.9%, 37.1%, 45.3%, and 45.2% for those originating from Africa, Europe, Asia, and other regions, respectively. CONCLUSIONS: Although the considered method was initially developed for cases with multiple biomarkers' measurements, its performance, when applied to data where only one CD4 count per individual is available, remains satisfactory. Application of the method to TESSy data, estimated that a substantial proportion of HIV acquisition among migrants occurs in destination countries, having important implications for public health policy and programs.

Early assessment of the impact of mitigation measures to control COVID-19 in 22 French metropolitan areas, October to November 2020.

In France, measures including curfew and lockdown were implemented to control the COVID-19 pandemic second wave in 2020. This study descriptively assesses their possible effects, also relative to their timing. A considerable decrease in incidence of COVID-19 cases and hospital admissions was observed 7 to 10 days after mitigation measures were put in place, occurring earlier in metropolitan areas which had implemented these first. This temporal coincidence suggests the measures' positive impact, consistent with international experiences.

Injecting drug use during sex (known as "slamming") among men who have sex with men: Results from a time-location sampling survey conducted in five cities, France.

BACKGROUND: In the last decade, European cities saw the development of "slamming," a practice related to chemsex that combines three elements: a sexual context, psychostimulant drug use, and injection practices. Epidemiological data on this practice is still sparse and media attention might have unintentionally distorted the size of this phenomenon. Therefore, we aimed to estimate the prevalence of men practicing slam and to identify factors associated with this practice. METHODS: We used data from the Prevagay 2015 bio-behavioral survey to estimate the prevalence of slamming practices. A time-location sampling was performed among gay-labeled venues in five French cites. Behavioral information was recorded using a self-administered questionnaire. The HIV and HCV serostatus were investigated using ELISA tests on dried blood spots. The factors associated with slamming were assessed using a multiple logistic regression. We applied a weighting mechanism to enhance the generalizability of the estimates. RESULTS: Among the 2646 men who have sex with men (MSM) included in our study, 3.1% reported slamming at least once during their lifetime (95% confidence interval (CI) = 2.2-4.3) and 1.6% (95% CI = 1-2.3) said they participated in a slamming session in the last 12 months. In the multivariate analysis, both HCV and HIV biological status were strongly associated with practicing "slam" in the last 12 months (OR = 13.37 (95% CI = 3.26-54.81) and 4.73 (95% CI = 1.58-14.44), respectively). Furthermore, a ten-point decrease in mental health scores was linked with the practice with an OR of 1.37 (95% CI = 1.08-1.73), indicating poorer mental health. CONCLUSION: Even though slamming seems to involve a relatively small proportion of MSM, the vulnerability of this sub-group is high enough to justify setting up harm reduction measures and specific care. Training health professionals and creating services combining sexual health and drug dependence could be an effective response.

Screening for Human Immunodeficiency Virus Infection by Use of a Fourth-Generation Antigen/Antibody Assay and Dried Blood Spots: In-Depth Analysis of Sensitivity and Performance Assessment in a Cross-Sectional Study.

We evaluated the performance of a fourth-generation antigen/antibody (Ag/Ab) assay for detecting HIV-1 infection on dried blood spots (DBS) both in a conventional laboratory environment and in an epidemiological survey corresponding to a real-life situation. Although a 2-log loss of sensitivity compared to that with plasma was observed when using DBS in an analytical analysis, the median delay of positivity between DBS and crude serum during the early phase postacute infection was 7 days. The performance of the fourth-generation assay on DBS was approximately similar to that of a third-generation (antibody only) assay using crude serum samples. Among 2,646 participants of a cross-sectional study in a population of men having sex with men, 428 DBS were found reactive, but negative results were obtained from 5 DBS collected from individuals who self-reported a positive HIV status, confirmed by detection of antiretroviral (ARV) drugs in their DBS. The data generated allowed us to estimate a sensitivity of 98.8% of the fourth-generation assay/DBS strategy in a high-risk population, even including a broad majority of individuals on ARV treatment among those HIV positive. Our study brings additional proofs that DBS testing using a fourth-generation immunoassay is a reliable strategy able to provide alternative approaches for both individual HIV testing and surveillance of various populations.

HCV and HBV prevalence based on home blood self-sampling and screening history in the general population in 2016: contribution to the new French screening strategy.

BACKGROUND: The advent of effective direct-acting antivirals (DAAs), has prompted an assessment of the French Hepatitis C virus (HCV) screening strategy, which historically targeted high-risk groups. One of the options put forward is the implementation of combined (i.e., simultaneous) HCV, Hepatitis B virus (HBV) and HIV screening for all adults at least once during their lifetime ("universal combined screening"). However, recent national survey-based data are lacking to guide decision-making regarding which new strategy to implement. Accordingly, we aimed to provide updated data for both chronic hepatitis C (CHC) and B (CHB) prevalence and for HCV and HBV screening history, using data from the BaroTest and 2016 Health Barometer (2016-HB) studies, respectively. METHODS: 2016-HB was a national cross-sectional phone based health survey conducted in 2016 among 20,032 randomly selected individuals from the general population in mainland France. BaroTest was a virological sub-study nested in 2016-HB. Data collected for BaroTest were based on home blood self-sampling on dried blood spots (DBS). RESULTS: From 6945 analyzed DBS, chronic hepatitis C (CHC) and B (CHB) prevalence was estimated at 0.30% (95% Confidence Interval (CI): 0.13-0.70) and 0.30% (95% CI: 0.13-0.70), respectively. The proportion of individuals aware of their status was estimated at 80.6% (95% CI: 44.2-95.6) for CHC and 17.5% (95% CI: 4.9-46.4) for CHB. Universal combined screening would involve testing between 32.6 and 85.3% of 15-75 year olds according to whether we consider only individuals not previously tested for any of the three viruses, or also those already tested for one or two of the viruses. CONCLUSIONS: Our data are essential to guide decision-making regarding which new HCV screening recommendation to implement in France. They also highlight that efforts are still needed to achieve the WHO's targets for eliminating these diseases. Home blood self-sampling may prove to be a useful tool for screening and epidemiological studies.

Antenatal HIV screening: results from the National Perinatal Survey, France, 2016.

BackgroundUniversal antenatal HIV screening programmes are an effective method of preventing mother-to-child transmission.AimsTo assess the coverage and yield of the French programme on a nationally representative sample of pregnant women, and predictive factors for being unscreened or missing information on the performance/ result of a HIV test.MethodsData came from the medical records of women included in the cross-sectional 2016 French National Perinatal Survey. We calculated odds ratios (OR) to identify factors for being unscreened for HIV and for missing information by multivariable analyses.ResultsOf 13,210 women, 12,782 (96.8%) were screened for HIV and 134 (1.0%) were not; information was missing for 294 (2.2%). HIV infection was newly diagnosed in 19/12,769 (0.15%) women screened. The OR for being unscreened was significantly higher in women in legally registered partnerships (OR: 1.3; 95% CI: 1.1-1.6), with 1-2 years of post-secondary schooling (OR: 1.6; 95% CI: 1.2-2.1), part-time employment (OR: 1.4; 95% CI: 1.1-1.8), inadequate antenatal care (OR: 1.9; 95% CI: 1.5-2.4) and receiving care from > 1 provider (OR: 1.8; 95% CI: 1.1-2.8). The OR of missing information was higher in multiparous women (OR: 1.4; 95% CI: 1.2-1.5) and women cared for by general practitioners (OR: 1.4; 95% CI: 1.1-1.9).ConclusionsThe French antenatal HIV screening programme is effective in detecting HIV among pregnant women. However, a few women are still not screened and awareness of the factors that predict this could contribute to improved screening levels.

Prevalence of hepatitis C infection, screening and associated factors among men who have sex with men attending gay venues: a cross-sectional survey (PREVAGAY), France, 2015.

BACKGROUND: Over the last 20 years, Hepatitis C virus (HCV) infection prevalence has dramatically increased among HIV-infected men who have sex with men (MSM) in many countries worldwide. It is suspected that this increase is primarily driven by sexual behaviours linked to blood exposure. Monitoring these behaviours is crucial to understand the drivers of the epidemic. This study assessed the prevalence of chronic HCV infection among MSM attending gay venues and associated chronic HCV risk factors. HCV screening and associated factors were described. METHODS: The cross-sectional survey PREVAGAY, based on time-location sampling, was conducted in 2015 among MSM attending gay venues in 5 French metropolitan cities. A self-administered questionnaire was completed and capillary whole blood on dried blood spots (DBS) collected. Possible factors associated with chronic HCV prevalence and with HCV screening in the previous year were investigated using Poisson regression. RESULTS: Chronic HCV infection prevalence from DBS analysis was 0.7% [IC95%: 0.3-1.5] in the study's 2645 participants and was 3.0% [1.5-5.8] in HIV-positive MSM. It was significantly higher in those who reported the following: (lifetime) slamming (with or without the sharing of injection equipment); (during the previous year) fisting and chemsex, unprotected anal intercourse with casual partners, using gay websites and/or of mobile-based GPS applications, and having more than 10 sexual partners. Only 41.3% [38.2-44.5] of the participants reported HCV screening during the previous year. Screening was significantly more frequent in MSM under 30 years of age, those who were HIV-positive, those vaccinated against hepatitis B and meningococcus C, and those who reported the following (during the previous year): more than 10 sexual partners, at least one sexually transmitted infection and fisting. CONCLUSION: Chronic HCV infection prevalence in MSM attending gay venues was significantly higher in HIV-positive MSM and in those with risky sexual behaviours. Reflecting current screening recommendations for specific populations, previous HCV screening was more frequent in HIV-positive individuals and those with risky sexual behaviours. Nevertheless, HCV screening coverage needs to be improved in these populations. Comprehensive medical management, which combines screening and linkage to care with prevention strategies, is essential to control HCV among MSM.

Emerging Shiga-toxin-producing Escherichia coli serogroup O80 associated hemolytic and uremic syndrome in France, 2013-2016: Differences with other serogroups.

To generate hypotheses on possible sources of Shiga toxin-producing Escherichia coli (STEC) serogroup O80 associated hemolytic-uremic syndrome (HUS), we explored differences in factors associated with STEC O80 associated HUS, compared with STEC O157 or STEC of other serogroups, in France during 2013-16. STEC was isolated from 153/521 (30%) reported HUS cases: 45 serogroup O80, 46 O157 and 62 other serogroups. Median ages were 1.1 years, 4.0 years and 1.8 years, respectively. O80 infected patients were less likely to report ground beef consumption (aOR [adjusted Odds Ratio] 0.14 95% CI [Confidence Interval] 0.02-0.80) or previous contact with a person with diarrhea or HUS (aOR 0.13 95%CI 0.02-0.78) than patients infected with STEC O157. They were also less likely to report previous contact with a person presenting with diarrhea/HUS than patients infected with other serogroups (aOR 0.13 95%CI 0.02-0.78). STEC O80 spread all over France among young children less exposed to known risk factors of O157 or other STEC infections, suggesting the existence of different reservoirs and transmission patterns.

Estimated Annual Numbers of Foodborne Pathogen-Associated Illnesses, Hospitalizations, and Deaths, France, 2008-2013.

Estimates of the annual numbers of foodborne illnesses and associated hospitalizations and deaths are needed to set priorities for surveillance, prevention, and control strategies. The objective of this study was to determine such estimates for 2008-2013 in France. We considered 15 major foodborne pathogens (10 bacteria, 3 viruses, and 2 parasites) and estimated that each year, the pathogens accounted for 1.28-2.23 million illnesses, 16,500-20,800 hospitalizations, and 250 deaths. Campylobacter spp., nontyphoidal Salmonella spp., and norovirus accounted for >70% of all foodborne pathogen-associated illnesses and hospitalizations; nontyphoidal Salmonella spp. and Listeria monocytogenes were the main causes of foodborne pathogen-associated deaths; and hepatitis E virus appeared to be a previously unrecognized foodborne pathogen causing ≈68,000 illnesses in France every year. The substantial annual numbers of foodborne illnesses and associated hospitalizations and deaths in France highlight the need for food-safety policymakers to prioritize foodborne disease prevention and control strategies.

Community Incidence of Campylobacteriosis and Nontyphoidal Salmonellosis, France, 2008-2013.

Community incidence estimates are necessary to assess the burden and impact of infections on health and to set priorities for surveillance, research, prevention, and control strategies. The current study was performed to estimate the community incidence of campylobacteriosis and nontyphoidal salmonellosis in France from the number of laboratory-confirmed cases reported to the national reference center (NRC). The probabilities of a case in the community visiting a doctor, having a stool sample requested, having a positive laboratory test, and having the case reported to the NRC were estimated using data of national surveillance systems, national hospitalization and health insurance databases, and specific surveys informing about these parameters. Credible intervals (CrI) were calculated using Monte Carlo simulation. In addition, we estimated the number of hospitalizations for both infections in France. The annual community incidence rate in France is estimated at 842 cases per 100,000 (90%CrI 525-1690) for campylobacteriosis and 307 cases per 100,000 (90%CrI 173-611) for salmonellosis. The annual number of hospitalizations is estimated at 5182 for campylobacteriosis and 4305 for salmonellosis. The multiplication factors between cases ascertained by the surveillance system and cases in the community were 115 for campylobacteriosis and 20 for salmonellosis. They are consistent with estimates reported in other countries, indicating a high community incidence of campylobacteriosis and salmonellosis in France.

Increased risk of miscarriage among women experiencing physical or sexual intimate partner violence during pregnancy in Guatemala City, Guatemala: cross-sectional study.

BACKGROUND: Violence against women by their male intimate partners (IPV) during pregnancy may lead to negative pregnancy outcomes. We examined the role of IPV as a potential risk factor for miscarriage in Guatemala. Our objectives were: (1) To describe the magnitude and pattern of verbal, physical and sexual violence by male intimate partners in the last 12 months (IPV) in a sample of pregnant Guatemalans; (2) To evaluate the influence of physical or sexual IPV on miscarriage as a pregnancy outcome. METHODS: All pregnant women reporting to the maternity of a major tertiary care public hospital in Guatemala City from June 1st to September 30th, 2006 were invited to participate in this cross-sectional study. The admitting physician assessed occurrence of miscarriage, defined as involuntary pregnancy loss up to and including 28 weeks gestation. Data on IPV, social and demographic characteristics, risk behaviours, and medical history were collected by interviewer-administered questionnaire. Laboratory testing was performed for HIV and syphilis. The relationship between IPV and miscarriage was assessed through multivariable logistic regression. RESULTS: IPV affected 18% of the 1897 pregnant Guatemalan women aged 15-47 in this sample. Verbal IPV was most common (16%), followed by physical (10%) and sexual (3%) victimisation. Different forms of IPV were often co-prevalent. Miscarriage was experienced by 10% of the sample (n = 190). After adjustment for potentially confounding factors, physical or sexual victimisation by a male intimate partner in the last 12 months was significantly associated with miscarriage (ORadj 1.1 to 2.8). Results were robust under a range of analytic assumptions. CONCLUSIONS: Physical and sexual IPV is associated with miscarriage in this Guatemalan facility-based sample. Results cohere well with findings from population-based surveys. IPV should be recognised as a potential cause of miscarriage. Reproductive health services should be used to screen for spousal violence and link to assistance.

A multistate approach for estimating the incidence of human immunodeficiency virus by using HIV and AIDS French surveillance data.

Before the introduction of highly active antiretroviral therapy (HAART) in 1996, monitoring the epidemics of HIV infection was extensively based on back-calculating the number of new HIV infections from AIDS surveillance data and knowledge of the AIDS incubation period distribution. However, the increase in the AIDS incubation period induced by HAART has complicated the use of AIDS diagnosis data only, and made it necessary to supplement these data with HIV diagnosis data. We explore the advantage of combining HIV and AIDS surveillance data in the context where the HIV diagnosis data are available only for the most recent years. Extending the earlier work of Aalen et al. (Statist. Med. 1997; 16(19):2191-2210) based on a discrete-time Markov model that describes simultaneously disease progression, HIV diagnosis and treatment intake, we propose a penalized likelihood approach to estimate smooth HIV incidence, together with HIV diagnosis rates. The smoothing parameter is chosen using an approximated cross-validation criterion. In a simulation study, we show that incorporation of HIV test information improves the precision of the estimation of the incidence of infections in recent periods. The method is illustrated using HIV and AIDS surveillance data collected by the Institut de Veille Sanitaire, France.