Surveillance Of HIV Infection Research Articles

Recent HIV Infection Surveillance Using a Rapid Test for Recent Infection among Persons Newly Diagnosed with HIV in Thailand: Establishment, Implementation, Initial outcomes, and Lessons Learned (Preprint)

Recent HIV Infection Surveillance Using a Rapid Test for Recent Infection among Persons Newly Diagnosed with HIV in Thailand: Establishment, Implementation, Initial outcomes, and Lessons Learned (Preprint)

Programmatic Implications of National Recent HIV Infection Surveillance in Cambodia.

We compared characteristics of HIV diagnosis and recent HIV infection (ie, likely acquired within the last year) in Cambodia. We included individuals ≥ 15 years old accessing HIV testing. From August 2020 to August 2022, 53 031 people were tested for HIV, 6868 were newly diagnosed, and 192 were recently infected. We found differences in geographical burden and risk behaviors with diagnosis and recency (eg, men who have sex with men, transgender women, and entertainment workers had a nearly 2-fold increased odds of testing positive for recent infection compared to being diagnosed with HIV). Recent infection surveillance may provide unique insights into ongoing HIV acquisition to inform programs.

Characterising persons diagnosed with HIV as either recent or long-term using a cross-sectional analysis of recent infection surveillance data collected in Malawi from September 2019 to March 2020

ObjectivesIn Malawi, a recent infection testing algorithm (RITA) is used to characterise infections of persons newly diagnosed with HIV as recent or long term. This paper shares results from recent...

COVID-19 pandemic and its impact on other infections in Northwest Russia

The purpose statement is to assess the course of the COVID-19 pandemic and its impact on the epidemics of HIV infection, viral hepatitis C (HCV), tuberculosis, influenza, and acute respiratory infections in the North-Western Federal District (NWFD) of the Russian Federation during two years of spreading COVID-19 from the standpoint of the possible formation of syndemia or interference between pathogens.Materials and methods. Data collection on HIV infection and HCV was carried out by Pasteur Research Institute of Epidemiology and Microbiology at St. Petersburg Medical Information and Analytical Center using data from federal state statistical observation forms and our own research materials. The indicators of excess mortality from all causes for 2020 in the Northwestern Federal District (NWFD) and in the Russian Federation were analyzed according to the data of the Federal State Statistics Service (ROSSTAT). The results of epidemiological surveillance of HIV infection, viral hepatitis C (HCV), and tuberculosis in the Russian Federation and in the NWED in 2020 and 2021 in comparison with previous years are summarized. Studies of influenza and SARS were carried out by Smorodintsev Research Institute of Influenza and Gamaleya National Research Center for Epidemiology and Microbiology in cooperation with regional support bases. PCR detection of ARVI pathogens was carried out.Results and discussion. An analysis of epidemic indicators across the territories of the Northwestern Federal District of the Russian Federation made it possible to identify the following features: heterogeneity of the incidence of COVID-19 in the population in terms of time and intensity; the prevalence of morbidity in the metropolis (St. Petersburg) and industrial northern regions (the republics of Karelia and Komi). In a comparative aspect, the NWFD belongs to regions with high morbidity and mortality in the Russian Federation. St. Petersburg (378 deaths per 100,000 people in 2021) ranks second after Moscow. In turn, the Vologda, Murmansk, and Arkhangelsk regions, as well as the Komi Republic are among the top ten of the most affected subjects of the Russian Federation in the country. In terms of mortality, St. Petersburg was significantly ahead of all other subjects of the Russian Federation and the national average, which had several probable reasons. The first and second years of the pandemic did not reveal significant changes in epidemic rates of morbidity and mortality from other socially significant infections — HIV, HCV, and tuberculosis at the population level characteristic interference of viruses, where SARS-CoV-2 took the place of interfering, and influenza and SARS pretending or interfering pathogens. It took several months until the beginning of winter 2020 to crowd out seasonal respiratory infections by SARS-CoV-2. Then SARS-CoV-2 tightly captured the epidemic space, leaving no room for traditional respiratory infections, which accounted for less than 5% in early 2022.Conclusion. The COVID-19 epidemic had pronounced developmental features with higher morbidity and mortality in the metropolis and other industrial centers. The pandemic did not significantly affect the patterns of the epidemic course of HIV, HCV, and tuberculosis, which rejected the presence of a syndemic between these pathogens. Interference with respiratory infections — influenza and SARS — was revealed with a clear predominance of SARS-CoV-2.

Estimating the incidence and diagnosed proportion of HIV infections in Japan: a statistical modeling study.

BackgroundEpidemiological surveillance of HIV infection in Japan involves two technical problems for directly applying a classical backcalculation method, i.e., (i) all AIDS cases are not counted over time and (ii) people diagnosed with HIV have received antiretroviral therapy, extending the incubation period. The present study aimed to address these issues and estimate the HIV incidence and the proportion of diagnosed HIV infections, using a simple statistical model.MethodsFrom among Japanese nationals, yearly incidence data of HIV diagnoses and patients with AIDS who had not previously been diagnosed as HIV positive, from 1985 to 2017, were analyzed. Using the McKendrick partial differential equation, general convolution-like equations were derived, allowing estimation of the HIV incidence and the time-dependent rate of diagnosis. A likelihood-based approach was used to obtain parameter estimates.ResultsAssuming that the median incubation period was 10.0 years, the cumulative number of HIV infections was estimated to be 29,613 (95% confidence interval (CI): 29,059, 30,167) by the end of 2017, and the proportion of diagnosed HIV infections was estimated at 80.3% (95% CI [78.7%–82.0%]). Allowing the median incubation period to range from 7.5 to 12.3 years, the estimate of the proportion diagnosed can vary from 77% to 84%.DiscussionThe proportion of diagnosed HIV infections appears to have not yet reached 90% among Japanese nationals. Compared with the peak incidence from 2005–2008, new HIV infections have clearly been in a declining trend; however, there are still more than 1,000 new HIV infections per year in Japan. To increase the diagnosed proportion of HIV infections, it is critical to identify people who have difficulty accessing consultation, testing, and care, and to explore heterogeneous patterns of infection.

Epidemiological HIV infection surveillance among subjects with risk behaviours in the city of Messina (Sicily) from 1992 to 2015.

Epidemiological studies are a key element in determining the evolution and spread of HIV infection among the world population. Knowledge of the epidemiological dynamics improves strategies for prevention and monitoring. We examined 2,272 subjects who voluntarily underwent HIV testing from January 1992 to December 2015. For each subject, an anonymous form was completed to obtain information on personal data, sexual habits and exposure to risk factors. The number of subjects undergoing the screening test has increased over the years and the average age of the tested subjects has decreased over time. The main motivation for undergoing HIV testing is unprotected sex. Although heterosexual subjects taking the test were more numerous than homosexuals in this study, an increase in the latter over time should be highlighted. Although the number of tests performed has increased over the years, the persistence of unprotected sex shows an inadequate perception of risk. Therefore, it is necessary to implement programmes to increase the general awareness of HIV infection. It is also essential to undertake constant monitoring of behaviour, risk perception and the application of the screening test via surveillance systems in order to implement effective and efficient prevention.

Surveillance of HIV Infection among Patients with Tuberculosis in Nepal

Introduction: Tuberculosis is one of the most prevalent infectious disease and significant public health problem in Nepal. The importance of HIV surveillance among tuberculosis (TB) patients is increasingly being recognized as the HIV epidemic continues to fuel the global TB epidemic. In many countries the HIV prevalence in TB patients is a sensitive indicator of the spread of HIV into the general population. The aim of this study is to find out the HIV epidemic among TB patients.Methodology: This was a periodic sentinel survey, i.e. cross-sectional HIV Sero-prevalence survey of all newly registered TB cases above 15 year old to provide point estimate. This survey was carried out in six major diagnostic centres of tuberculosis of Nepal from July 2012 to February 2013. The calculated sample size for the surveillance study was 1000. The findings were processed/analyzed using SPSS (version 16) computer software. Descriptive statistics was used to observe the pattern in each variable.Results: The study revealed that four-fifth (80.9%) TB patients investigated were pulmonary positive and one-fifth (19.1%) extra pulmonary. Prevalence of HIV among tested TB patients was 2.4% and prevalence was comparatively more (2.8%) in Male than Female (1.4%). Sentinel site wise prevalence of HIV was higher (6.7%) in United Mission to Nepal (UMN), Palpa followed by 3.1%, 2.9% and 2.7% in District Public Health Office (DPHO), Kanchanpur, International Nepal Fellowship (INF), Nepalgunj and Regional tuberculosis Centre (RTC), Pokhara respectively. Comparatively prevalence was low (1.3%) in National Tuberculosis Centre (NTC), Thimi and not a single case of HIV among tested TB patients was found in Nepal Anti-TB Association (NATA), Biratnagar. Significant proportion (7.8%) of HIV prevalence was found in the age group of 35-39 years followed by 4.6%, 3.6% and 2.8% among the age group of 40-44 years, 50-54 years and 30-34 years age group respectively.Conclusion: Among all TB/HIV co-infected, significant proportion is found in 35-39 years and lowest in 20-24 age groups. Therefore, it is important to implement targeted interventions in the age group between 30-55 years age group. Provider Initiated Testing and Counseling (PITC) in TB clinical setting plays important role to enroll more TB patients for HIV test.SAARC J TUBER LUNG DIS HIV/AIDS, 2015; 12(1), Page: 25-30

Surveillance for HIV infection in MSM selected through respondent driven sampling in Beijing, 2005-2012

Objective: To understand the HIV prevalence among men who have sex with men (MSM) and discuss the feasibility of respondent driven sampling (RDS) as a tool to conduct long term HIV surveillance in MSM in Beijing. Methods: From 2005 to 2012 RDS was used to recruit MSM for face-to-face interview with structured questionnaire to collect their demographic characteristics and HIV risk-related behavior. Blood samples were collected from them for HIV test. Results: A total of 427, 540, 607, 614, 616, 602, 579 and 600 MSM were surveyed, respectively, from 2005 to 2012. The HIV infection prevalence increased from 4.2%(95%CI: 1.9-7.0) in 2005 to 10.1% (95%CI: 7.2-13.2) in 2012 (P=0.02). Meanwhile, HIV prevalence substantially increased among MSM aged >25 years, in floating population and with lower education level (≤high school), from 6.4%(95%CI: 2.2-9.5), 3.3%(95%CI: 1.8-5.4) and 5.5% (95%CI: 2.2-8.9) in 2005 to 7.6% (95%CI: 5.4-10.3, P=0.04), 10.7% (95% CI: 7.8-14.6, P=0.04) and 10.4% (95% CI:7.2-14.3, P=0.04) in 2012, respectively. Moreover, the HIV infection prevalence in MSM aged ≤25 years old and with higher education level (>high school) increased from 1.7%(95%CI: 0.4-3.1) in 2009 and 1.1%(95%CI: 0.2-1.7) in 2007 to 13.7%(95%CI: 7.2-20.4) and 9.1%(95%CI: 4.7-13.8) in 2012, respectively, the differences were not significant. Furthermore, the HIV infection prevalence in MSM who had 2-9 male sex partners in the last six months increased from 4.0% (95% CI: 1.0-8.0) in 2005 to 12.6% (95% CI: 8.7-16.7) in 2012 (P=0.02). Conclusions: Studies have shown that RDS is an effective and feasible sampling method for long term HIV surveillance in MSM. The HIV infection prevalence in MSM in Beijing increased from 2005 to 2012, especially among those with older age, in floating population and with lower educational level. More attention should be paid to MSM with younger age and with higher educational level.

Outcomes related to 4864 pregnancies with exposure to lopinavir/ritonavir (LPV/r).

IntroductionDuring pregnancy, LPV/r is a common anchor drug employed to treat the mother's HIV-1 infection in addition to reducing the risk of mother-to-child transmission (MTCT). The National Study of HIV in Pregnancy and Childhood (NSHPC) conducts a comprehensive population-based surveillance of HIV infection in pregnant women exposed to antiretroviral therapy (ART) in the UK and Ireland; in 2003–2012 over a third of pregnancies reported to the NSHPC involved exposure to LPV/r.MethodsWe undertook a retrospective were descriptive analysis of individual NSHPC patient data, using pregnancy as the unit of observation. Clinical outcomes for pregnancies reported by June 2013, where women were exposed to LPV/r and due to deliver between January 2003 and December 2012, are described.ResultsA total of 4864 LPV/r exposed pregnancies in 4118 women were identified. These resulted in 4702 deliveries with 4759 live and 46 stillborn infants. Seventy five percent of women were born in sub-Saharan Africa, 13% in the UK or Ireland. Median maternal age at conception was 30 years. Nine hundred and eighty (20%) pregnancies were conceived while taking LPV/r, with a median duration of LPV/r exposure of 270 days. A total of 3884 (80%) pregnancies initiated LPV/r after conception, with a median duration of LPV/r exposure of 107 days. Viral load (VL) close to delivery was available for 4083/4702 (87%) deliveries, with VL <50 c/mL in 73% and <1000 c/mL in 94% of women. VL by timing of LPV/r initiation is shown in Table 1. Sixty three percent of deliveries were by C-section, of which 62% were classified as elective and 38% as emergency. Among singleton liveborn infants, 13% were born prior to 37 weeks gestation (2.5% <32 weeks) and 15% had birth weight <2500 g (2.3% <1500 g). HIV infection status was available for 4039 (89%) singleton infants. For the periods 2003–2007 and 2008–2012, MTCT rates were 1.1% (95% CI 0.6–1.6) and 0.5% (95% CI 0.2–0.8) respectively. Hundred and thirty four live born children (2.8%) had at least one congenital abnormality reported.ConclusionsIn the NSHPC database, in women exposed to LPV/r during pregnancy in the UK and Ireland, MTCT rates are low and continue to decline, and are similar to rates in the entire NSHPC cohort of women with diagnosed HIV [1]. The congenital abnormality rate is comparable with that reported for the uninfected population in this geographic region.

P3.131 Trends in HIV Infection Surveillance Data Among Men Who Have Sex with Men in Albania, 1993–2012

BackgroundAlbania is still a low HIV prevalence country, however the recent reports on the growing HIV reported cases per year show an increase of reported HIV among MSM in Albania....

Trends in HIV infection surveillance data among men who have sex with men in Norway, 1995-2011

BackgroundRecent reports on the growing HIV epidemic among men who have sex with men (MSM) in the EU/EEA area were accompanied by an increase of reported HIV among MSM in Oslo, Norway in 2003. Our study with data from 1995 to 2011 has described the recent trends of HIV among MSM in Norway and their socio-demographic and epidemiological characteristics.MethodsThe data were collected from the Norwegian Surveillance System for Communicable Diseases. Cases were described by age, place of infection, clinical presentation of HIV infection, STI co-infection and source partner. We used simple linear regression to estimate trends over time.ResultsDuring the study period, 991 MSM, aged from 16 to 80 years, were newly diagnosed with HIV. No significant trends over time in overall median age (36 years) were observed. Most of the MSM (505, 51%) were infected in Oslo. In the years 1995-2002, 30 to 45 MSM were diagnosed with HIV each year, while in the years 2003-2011 this increased to between 56 and 97 cases. The proportion of MSM, presenting with either AIDS or HIV illness, decreased over time, while asymptomatic and acute HIV illness increased (p for trend=0.034 or less). STI co-infection was reported in 133 (13%) cases. An overall increase of syphilis co-infected cases was observed (p for trend <0.001). A casual partner was a source of infection in 590 cases (60%).ConclusionsThough the increases described could be attributed to earlier testing and diagnosis, no change in the median age of cases was observed. This indicates that it is likely that there has been an increase in HIV infections among MSM in Norway since 2003. The simultaneous increase in STI co-infections indicates risky sexual behaviour and a potential to spread both HIV and other sexually transmitted infections.

Supervision and Quality Control Measures in Annual Sentinel Surveillance for HIV Infection in India

The National Institute of Health and Family Welfare (NIHFW) has been entrusted by the National AIDS Control Organisation (NACO) to undertake monitoring and supervision of annual Sentinel Surveillance (ASS) activity in India since 1998, to ensure that the data obtained are valid. Earlier Regional coordinating teams cooperated with NIHFW in this task. From 2006 onwards, NACO identified five regional institutes covering all the states and Union Territories and Central team members consisting of experts from various organisations for the monitoring and supervision of the ASS cycle to ensure quality control of both epidemiological data collection and HIV testing (NACO 2006a and b). We describe here the process of quality control and observations of the ASS rounds held from 2005 to 2007. The performance of a majority of sites was satisfactory. The testing laboratories usually adhered to standard operating procedures (SOPs). Lacunae observed during the supervisory visits have been enumerated along with the recommendations for the future surveillance rounds.

Co‐circulation HIV‐1 subtypes B, C, and CRF31_BC in a drug‐naïve population from Southernmost Brazil: Analysis of primary resistance mutations

In Southernmost Brazil HIV-1 subtypes B, C, and CRF31_BC co-circulates and, since 1996 with the implementation of free access to highly active antiretroviral treatment (HAART), this epidemic is under a quite characteristic selective pressure. The profile of mutations and polymorphisms in the protease (PR) and reverse transcriptase (RT) genes of HIV-1 from untreated patients living in Porto Alegre, Southernmost Brazil were evaluated in order to identify the subtypes and circulating drug resistant genotypes. Blood samples from 99 HIV-1 positive drugs-naïve patients were collected from 2006 to 2007 in Porto Alegre, Brazil. HIV PR and RT genes were amplified, sequenced, and subtyped. The HIV-1 genotyping was performed by partial sequence analysis of the pol in the HIV Drug Resistance Database of Stanford University. Phylogenetic analyses allowed to classify the HIV samples according to their subtypes: B (26.2%), C (39.4%), F (1.1%), CRF31_CB (19.2%), and URF (14.1%). Eight (8.1%) samples showed primary resistance mutations according to the Calibrated Population Resistance tool based in the 2009 Surveillance Drug Resistance Mutation list. Two samples presented resistance mutations to PI, three NRTI and three NNRTI. There was no significant association between presence of resistant genotypes and subtypes, but resistance mutations seem to be less frequent in the subtype C. In addition, this study describes for the first time the mutational profile of CRF31_BC to PI, NRTI, and NNRTI. Genetic analyses of HIV-1 from naïve patients are a promising and important method for surveillance of HIV infection.

Change of Positive Selection Pressure on HIV-1 Envelope Gene Inferred by Early and Recent Samples

HIV-1 infection has been on the rise in Japan recently, and the main transmission route has changed from blood transmission in the 1980s to homo- and/or hetero-sexual transmission in the 2000s. The lack of early viral samples with clinical information made it difficult to investigate the possible virological changes over time. In this study, we sequenced 142 full-length env genes collected from 16 Japanese subjects infected with HIV-1 in the 1980s and in the 2000s. We examined the diversity change in sequences and potential adaptive evolution of the virus to the host population. We used a codon-based likelihood method under the branch-site and clade models to detect positive selection operating on the virus. The clade model was extended to account for different positive selection pressures in different viral populations. The result showed that the selection pressure was weaker in the 2000s than in the 1980s, indicating that it might have become easier for the HIV to infect a new host and to develop into AIDS now than 20 years ago and that the HIV may be becoming more virulent in the Japanese population. The study provides useful information on the surveillance of HIV infection and highlights the utility of the extended clade models in analysis of virus populations which may be under different selection pressures.

Epidemiología de la infección por virus de la inmunodeficiencia humana. Retraso en el diagnóstico

Epidemiological surveillance of HIV infection has made notably progress over the last decade, improving knowledge of its characteristics and adapting treatment accordingly. On the other hand, the delayed diagnosis of HIV infection is still an important problem to reduce transmission and improve epidemic control both national and internationally. Although the increased availability of new testing technologies over the last ten years, progress, although statistically significant,in reducing late diagnosis in Spain has been, insufficient in terms of public health, meaning that additional efforts should be put in place to review strategies and increase accessibility to tests, population awareness and decrease the lost opportunities for early diagnosis.

Increase in HIV diagnoses among men who have sex with men in New Zealand from a stable low period

To describe trends in HIV diagnoses among men who have sex with men (MSM) in New Zealand 1996-2008, and to identify characteristics associated with HIV diagnoses in the resurgent phase. Data collected through routine surveillance of HIV infection, where the mode of transmission included homosexual contact, were analysed over the period 1996-2008. Annual HIV diagnoses were low during 1996-2000, rose sharply between 2001 and 2005, and remained at an elevated plateau between 2006 and 2008. Over a quarter were attributed to HIV infection acquired overseas (28.6%). Trends in diagnoses of locally acquired HIV infection closely mirrored the trend of three diagnosis phases. Increases in locally acquired HIV occurred among virtually all characteristics of MSM. However, compared with MSM diagnosed in the low phase 1996-2000, individuals diagnosed in the resurgent phase 2001-05 were more likely to be aged 30-39, to have tested HIV-negative within the previous 2 years, to live in the Northern region encompassing Auckland, and to be of non-European ethnicity. The per capita HIV diagnosis rate among MSM was lowest in 1997, at 22.0 per million males aged 15-64, and highest in 2005 at 66.7 per million. The increase in HIV diagnoses among MSM in New Zealand was primarily due to an increase in locally acquired HIV infection, which disproportionately affected some groups of MSM. Factors driving this change in local epidemic conditions need to be identified. The rate of new HIV diagnoses among MSM remains low by international standards.

An improved data-collection form for the surveillance of HIV infection in Italy

Background: The data-collection form used for Italy's recently established national HIV surveillance systemdoes not include sufficient information to thoroughly describe the dynamics of the epidemic. In addition,comparisons with data from other European countries are difficult. To address this issue, we have developeda more detailed form based on forms used in other European countries.Methods: Data-collection forms used in other countries were evaluated, and the information collected wascategorised by topic. Based on this evaluation, a form was developed for use in Italy.Results: The forms used in other countries are more detailed than the Italian form, and we propose addingthe following information to the Italian form: i) the year of entry in Italy for non-nationals; ii) testing pattern(i.e., the number of tests in the previous two years and during lifetime); iii) whether or not infection wasrecent, based on the antibody avidity index, and which test and cut-off were used; iv) whether or not testingwas performed in the acute phase of infection, based on symptoms; and v) a checklist of reasons forundergoing testing. We also added a “Comments” section for information not recorded elsewhere on theform.Discussion: The more detailed form will allow for a more thorough description of the characteristics of newlyinfected persons and of the dynamics of the epidemic in Italy, which is fundamental for prevention and controlinitiatives. It will also allow for comparisons to be made against data from other European countries, revealingimportant similarities and differences.

O653 Sentinel surveillance of HIV infection in pregnant women in RIMS Imphal

O653 Sentinel surveillance of HIV infection in pregnant women in RIMS Imphal

Chlamydia in the Pacific Region, the Silent Epidemic

Second generation surveillance of HIV infection and sexually transmitted infections (STIs) among pregnant women in 6 Pacific Island Countries and Territories were undertaken to improve knowledge and to make recommendations on future prevention and management of STIs. Cross-sectional studies, using standardized questionnaire, laboratory tests, and protocols were undertaken in Fiji, Kiribati, Samoa, Solomon Islands, Tonga, and Vanuatu between 2004 and 2005. For each country, between 200 and 350 pregnant women aged 15 to 44 years were consecutively recruited from antenatal clinics located in the main hospital of the major urban centre of each Pacific Island Countries and Territories. Consenting participants were interviewed about their socio-demographic characteristics and their sexual behavior, and were tested for HIV, chlamydia, syphilis (Treponema pallidum antibody seroactivity), and gonorrhoea. Amongst the 1618 pregnant women studied, the most prevalent STI was chlamydia with 26.1% of women under 25 and 11.9% of women aged 25 years and over being positive. Highest infection was detected in single teenage women with 38.1% positive for chlamydia. The overall prevalence of gonorrhoea and syphilis was 1.7% and 3.4%, respectively. No case of HIV was detected. Chlamydia infection was independently associated with younger age, being nulliparous, single status, multiple lifetime sexual partners, and commercial sex activity. In a population of young women, chlamydia infection was endemic. Regional leadership is needed to implement strategies to prevent the spread of chlamydia and to implement HIV and STI prevention and management.

Near Full-Length Genomic Analysis of a Novel Subtype A1/C Recombinant HIV Type 1 Isolate from Canada

The rapid introduction of non-B HIV-1 subtypes into Quebec, mostly from persons from regions where HIV prevalence is high and where different variants circulate, means that recombination must now be an important consideration in the epidemiologic surveillance of HIV infection. No circulating recombinant form (CRF), currently involving exclusively subtypes A1 and C, exists in the Los Alamos HIV database. This study presents a near full-length genomic analysis of a novel HIV-1 recombinant involving subtypes A1 and C. Bootscanning revealed that the recombinant structure involves three breakpoints that separate the genome into four regions, alternating between subtypes A1 and C. The intersubtype recombinant breakpoint in the pol gene was at midpoint between the protease and reverse transcriptase open reading frames. This is the first report of a recombinant involving subtypes A1 and C in Canada, the epidemiologic significance of which is not yet known.