National Seroprevalence Research Articles

Prevalence and vaccination coverage of Hepatitis B among healthcare workers in Cameroon: A national seroprevalence survey.

Hepatitis B virus (HBV) infection is hyperendemic in Cameroon, and healthcare workers (HCWs) are at high risk of infection. We aimed to assess prevalence, risk factors and vaccine coverage of HBV infection among HCWs in Cameroon. We conducted a cross-sectional study in 16 hospitals across all regions of Cameroon. HCWs were tested for HBV using rapid diagnostic tests (RDT). We collected data on socio-demographics and HBV vaccination status. We estimated prevalence of HBV and used Poisson regression models with robust standard errors to model the prevalence ratios of HBV positivity between covariates. We enrolled 1824 of 1836 eligible HCWs (97.5%). The mean age was 34 (SD: 10) years, 65.3% (n=1787) were women, and 11.4% (n=1747) had three or more doses of the HBV vaccine. Overall, we found a HBV prevalence of 8.7% (95% CI: 5.2%-14.3%). Patient transporters had the highest crude prevalence (14.3%; 95%CI: 5.4%-32.9%), whereas medical doctors had the lowest (3.2%; 95%CI: 0.8%-12.1%). The Far North Region had the highest prevalence of HBV (24.0%; 95%CI: 18.3%-30.8%). HBV prevalence decreased with increasing doses of the HBV vaccine (10.3% for no doses vs 3.5% for three or more doses; P<0.001). In conclusion, approximately 1 in 12 HCWs in Cameroon have evidence of HBV infection, yet fewer than 1 in 6 have been fully vaccinated. Our results illustrate the urgent need to scale up systematic HBV screening and targeted vaccination of HCWs in the region.

Antibodies prevalence against Haemophilus influenzae type b in Jeddah population, Saudi Arabia. I. Total antibodies.

In this national comprehensive seroprevalence study, indirect ELISA test was used to evaluate Haemophilus influenzae type b (Hib) anti-polyribosyl-ribitol phosphate (PRP) total antibodies (IgM, IgG, IgA) in 1,003 sera samples from routine medical check-up of healthy individuals attending the local medical facility in Jeddah, Saudi Arabia in the period from February 2014 to January 2016. Serum anti-CPS antibodies confer immunity against invasive Hib disease. An anti-CPS concentration of ⩾0.15 μg/mL is believed to be a serological indication for short-term immunity protection against invasive Hib disease, while a concentration of ⩾ 1.0 μg/mL is believed to be long-term protective. Results showed higher level of anti-Hib IgG (2.41 μg/ml average geometric mean concentration (GMC) regardless of age and gender, followed by levels of IgM (0.91 μg/ml) and IgA (0.34 μg/ml), reflecting the community immunity against Hib. Low anti-Hib level (< 0.15 μg/ml of anti-PRP IgG) in elderly people (males aged 57-91 years and females aged 35-64 years) may indicate a need for a booster dose of Hib vaccine to elderly people in the community. The IgG prevalence over IgM, and IgM prevalence over IgA indicate the major role of IgG over IgM and IgA in keeping immunity in the track against Hib. Low level of IgM and IgA comparing to IgG may indicate the absence of Hib acute infections in the population.

Ingesting Self-Grown Produce and Seropositivity for Hepatitis E in the United States.

Background Hepatitis E virus (HEV) is a major cause of hepatitis in developing and industrialized countries worldwide. The modes of HEV transmission in industrialized countries, including the United States, remain largely unknown. This study is aimed at evaluating the association between HEV seropositivity and consumption of self-grown foods in the United States. Methods Cross-sectional data was extracted from the 2009–2012 National Health and Nutrition Examination Survey (NHANES). Data from the dietary interview and the serum HEV IgG and IgM enzyme immunoassay test results were linked and examined. Univariate and multivariable logistic regression models were used to evaluate the significance and effect size of an association between self-grown food consumption and hepatitis E seropositivity. Results The estimated HEV seroprevalence in the civilian, noninstitutionalized US population was 6.6% in 2009–2012, which corresponds to an estimated hepatitis E national seroprevalence of 17,196,457 people. Overall, 10.9% of participants who ingested self-grown foods had positive HEV antibodies versus 6.1% of participants who did not consume self-grown foods (P < 0.001; odds ratio (OR) 1.87; 95% CI 1.41–2.48). In the age-stratified multivariable analysis, the correlation between ingesting self-grown foods and HEV seropositivity was significant for participants 40–59 years old, but not overall, or for those < 40 years or ≥60 years. Conclusions Ingesting self-grown food, or simply the process of gardening/farming, may be a source of zoonotic HEV transmission.

National surveillance plan for infectious bovine rhinotracheitis (IBR) in autochthonous Italian cattle breeds: Results of first year of activity

Infectious bovine rhinotracheitis (IBR)/infectious pustular vulvovaginitis (IPV) caused by Bovine alphaherpesvirus 1 (BoHV-1) is a significant disease in domestic and wild cattle. In June 2015, the Ministry of Agriculture, Food and Forestry in Italy approved a national surveillance plan to control and eradicate IBR in beef cattle breeds. The objective of this study was to evaluate the results of the first year of the IBR voluntary surveillance plan in Italy. The aim of the plan is to eradicate IBR in all bovines recorded in the National Herd Book for Italian beef cattle breeds over six years. Monetary incentives are used to encourage breeders to achieve the annual seroprevalence ranges stated in the plan. A Ministerial decree states that all bovines in breeding herds and aged older than 12 months should be serologically tested. Serum samples were tested for presence of the antibody to glycoprotein E of BoHV-1 using commercially available enzyme-linked immunosorbent assays. The national herd seroprevalence was 55.49% (95% confidence interval [CI] 52.01–58.92). Of 25,121 bovines tested for antibodies against BoHV-1, 8014 were positive. The seroprevalence in animals from autochthonous Italian cattle breeds was 31.89% (95% CI 31.31–32.47). Seroprevalence was highest in Podolica cattle (55.14%; 95% CI 54.07–56.21), lowest in Maremmana cattle (9.95%; 95% CI 7.99–12.31), and intermediate in Chianina (22.01%; 95% CI 21.03–23.01), Marchigiana (24.85%; 95% CI 23.52–26.23), and Romagnola (15.60%; 95% CI 14.62–16.64) cattle. These seroprevalence rates indicate a need for intervention to decrease the inevitable severe economic losses arising from BoHV-1 infection. Although some regions in Italy have a long history of combatting BoHV-1 infection, only the province of Bolzano has eradicated IBR.

Importance and Contribution of Community, Social, and Healthcare Risk Factors for Hepatitis C Infection in Pakistan.

Pakistan has a high prevalence of hepatitis C virus (HCV) infection, estimated at 4.9% (2,290/46,843) in the 2007 national HCV seroprevalence survey. We used data from this survey to assess the importance of risk factor associations with HCV prevalence in Pakistan. Exposures were grouped as community (going to the barbers, sharing smoking equipment, having an ear/nose piercing, tattoo, or acupuncture), healthcare (ever having hemodialysis, blood transfusion, or ≥ 5 injections in the last year), demographic (marital status and age), and socio-economic (illiterate or laborer). We used mutually adjusted multivariable regression analysis, stratified by sex, to determine associations with HCV infection, their population attributable fraction, and how risk of infection accumulates with multiple exposures. Strength of associations was assessed using adjusted odds ratios (aOR). Community [aOR females 1.5 (95% confidence interval [CI]: 1.2, 1.8); males 1.2 (1.1, 1.4)] and healthcare [females 1.4 (1.2, 1.6); males 1.2 (1.1, 1.4)] exposures, low socio-economic status [females 1.6 (1.3, 1.80); males 1.3 (1.2, 1.5)], and marriage [females 1.5 (1.2, 1.9); males 1.4 (1.1, 1.8)] were associated with increased HCV infection. Among married women, the number of children was associated with an increase in HCV infection; linear trend aOR per child 1.06 (1.01, 1.11). Fewer infections could be attributed to healthcare exposures (females 13%; males 6%) than to community exposures (females 25%; males 9%). Prevalence increased from 3% to 10% when cumulative exposures increased from 1 to ≥ 4 [aOR per additional exposure for females 1.5 (1.4, 1.6); males 1.2 (1.2, 1.3)]. A combination of community, healthcare, and other factors appear to drive the Pakistan HCV epidemic, highlighting the need for a comprehensive array of prevention strategies.

National South African HIV prevalence estimates robust despite substantial test non-participation.

South African (SA) national HIV seroprevalence estimates are of crucial policy relevance in the country, and for the worldwide HIV response. However, the most recent nationally representative HIV test survey in 2012 had 22% test non-participation, leaving the potential for substantial bias in current seroprevalence estimates, even after controlling for selection on observed factors. To re-estimate national HIV prevalence in SA, controlling for bias due to selection on both observed and unobserved factors in the 2012 SA National HIV Prevalence, Incidence and Behaviour Survey. We jointly estimated regression models for consent to test and HIV status in a Heckman-type bivariate probit framework. As selection variable, we used assigned interviewer identity, a variable known to predict consent but highly unlikely to be associated with interviewees' HIV status. From these models, we estimated the HIV status of interviewed participants who did not test. Of 26 710 interviewed participants who were invited to test for HIV, 21.3% of females and 24.3% of males declined. Interviewer identity was strongly correlated with consent to test for HIV; declining a test was weakly associated with HIV serostatus. Our HIV prevalence estimates were not significantly different from those using standard methods to control for bias due to selection on observed factors: 15.1% (95% confidence interval (CI) 12.1 - 18.6) v. 14.5% (95% CI 12.8 - 16.3) for 15 - 49-year-old males; 23.3% (95% CI 21.7 - 25.8) v. 23.2% (95% CI 21.3 - 25.1) for 15 - 49-year-old females. The most recent SA HIV prevalence estimates are robust under the strongest available test for selection bias due to missing data. Our findings support the reliability of inferences drawn from such data.

Dengue seroprevalence and force of primary infection in a representative population of urban dwelling Indonesian children.

BackgroundIndonesia reports the second highest dengue disease burden in the world; these data are from passive surveillance reports and are likely to be significant underestimates. Age-stratified seroprevalence data are relatively unbiased indicators of past exposure and allow understanding of transmission dynamics.Methodology/Principal FindingsTo better understand dengue infection history and associated risk factors in Indonesia, a representative population-based cross-sectional dengue seroprevalence study was conducted in 1–18-year-old urban children. From October to November 2014, 3,210 children were enrolled from 30 geographically dispersed clusters. Serum samples were tested for anti-dengue IgG antibodies by indirect ELISA. A questionnaire investigated associations between dengue serologic status and household socio-demographic and behavioural factors. Overall, 3,194 samples were tested, giving an adjusted national seroprevalence in this urban population of 69.4% [95% CI: 64.4–74.3] (33.8% [95% CI: 26.4–41.2] in the 1–4-year-olds, 65.4% [95% CI: 69.1–71.7] in the 5–9-year-olds, 83.1% [95% CI: 77.1–89.0] in the 10–14-year-olds, and 89.0% [95% CI: 83.9–94.1] in the 15–18-year–olds). The median age of seroconversion estimated through a linear model was 4.8 years. Using a catalytic model and considering a constant force of infection we estimated 13.1% of children experience a primary infection per year. Through a hierarchical logistic multivariate model, the subject’s age group (1–4 vs 5–9 OR = 4.25; 1–4 vs. 10–14 OR = 12.60; and 1–4 vs 15–18 OR = 21.87; p<0.0001) and the number of cases diagnosed in the household since the subject was born (p = 0.0004) remained associated with dengue serological status.Conclusions/SignificanceThis is the first dengue seroprevalence study in Indonesia that is targeting a representative sample of the urban paediatric population. This study revealed that more than 80% of children aged 10 years or over have experienced dengue infection at least once. Prospective incidence studies would likely reveal dengue burdens far in excess of reported incidence rates.

Human Immunodeficiency Virus (HIV) Related Conjunctival Tumours

Background: The huge burden of HIV/AIDS in sub-Saharan Africa has been associated with increased prevalence of malignant conjunctival tumours especially squamous cell carcinoma (SCC). In Nigeria, the national HIV sero-prevalence is 3.4%, and values in the South-South geopolitical zone where this review was performed ranges from 4.1% in Delta to 10.9% in Akwa-Ibom state. Aim: To review HIV and conjunctival tumours in patients seen at the University of Calabar Teaching Hospital (UCTH), Calabar Methodology: This retrospective clinic review of demographic data, clinical features, HIV sero-status and histopathologic findings in patients with conjunctival tumours seen from January 2005 to December 2014 including Ophthalmology clinic records and pathology request forms were analysed Results: A total of 32,102 new patients were seen in the ophthalmic outpatient within the study period, of which 108 patients comprising 57(52.8%) males and 42(38.0%) females had conjunctival tumours. Their ages ranged from 11-85 years, with a mean of 39 years ± 14.98. Histologically, eighty (74.1%) had Squamous cell carcinoma, ten (9.26%) Squamous intraepithelial lesion, six (5.56%) Papilloma, four (3.7%) Kaposis sarcoma, three (2.78%) Naevus and Melanoma each, one each (0.93%) had Conjunctival dysplasia and Lymphoma. The HIV status of only 55 (50.9%) could be ascertained having been documented in patients’ records of whom thirty-seven (67.3%) were HIV positive. Thirty four (>90%) of the HIV positive cases had squamous cell carcinoma. The other 3 patients had kaposis sarcoma, papilloma and conjunctival intraepithelial neoplasia(CIN). Conclusion: In Calabar, conjunctival squamous cell carcinoma is preponderant in HIV sero-positive patients when compared with the sero-negatives.

Seroepidemiology of HIV in Moyamba District, Sierra Leone, 2013-2016

HIV infection is one of the health problems plaguing resource-poor countries. There are limited data on the prevalence in remote towns and districts. In this study we aimed at investigating the seroprevalence of HIV in Moyamba District using data from voluntary counseling and testing(VCT), prevention of mother-to-child transmission of HIV(PMCT) and from blood donors from 2013 to 2016.The seroprevalence of HIV from VCT was 2.87%(357/12434) for the four years, 2013 to 2016. Seroprevalence from PMCT was 0.91%(153/16,745) while the prevalence from healthy blood donors was 1.53%(27/1756). Overall, 537 persons tested positive for HIV out of 30,935 persons tested in Moyamba from 2013 to 2016 with a prevalence of 1.74(95%CI:1.6-1.89%).Statistically, our result is significantly different from the results of the DHS where HIV seroprevalence was reported at 1.0% in Moyamba(P&lt;0.001).Our result provide an update on the HIV situation in Moyamba and shows an epidemic that is consistent with the national seroprevalence of 1.5%.

Hepatitis C in Cameroon: What is the progress from 2001 to 2016?

Chronic hepatitis C is a major public health problem in sub-Saharan countries and particularly in Cameroon where the prevalence rate is around 7.6% in the age group of 55-59 years. Recent investigations into this infection allowed defining a national seroprevalence, characterizing virological and biological profiles of infected patients and identifying medicinal plants of potential interest in hepatitis C therapy. However, in Cameroon, no existing report currently presents a good overview of hepatitis C research in relation to these parameters. This review seeks to discuss major findings published since 2001 that have significantly advanced our understanding of the epidemiology and treatment of hepatitis C in Cameroonian patients and highlight the major challenges that remain to overcome. We performed a systematic search in Pubmed and Google Scholar. Studies evaluating prevalence, treatment, coinfection, and genetic diversity of HCV infection in Cameroon were included. Studies suggest that HCV prevalence in Cameroon would be low (around 1.1%) with a lot of disparities according to regions and age of participants. Elders, pregnant women, blood donors, health care workers, patients on hemodialysis, and homozygous sickle cell patients have been identified as risk groups. Moreover, HCV/HBV coinfection was found more prevalent than HCV/HIV coinfection. Phylogenic studies reported circulation of three main genotypes such genotypes 1, 2, and 4 but little is known about antiviral candidates from the Cameroonian pharmacopeia. In conclusion, some epidemiological data prove that hepatitis C in Cameroon is well known but efforts are still necessary to prevent or control this infection.

Risky exposures and national estimate of HCV seroprevalence among school children in urban Egypt.

Hepatitis C virus (HCV) is a significant cause of morbidity and mortality all over the world, particularly in Egypt. Limited data are available concerning the national seroprevalence and the possible modes of transmission of HCV in the pediatric age group. The aim of this study was to obtain a better estimate of the national hepatitis C seroprevalence and the possible risky exposures among healthy school children in Alexandria; the second biggest city in Egypt. HCV knowledge and counseling for school children were also investigated. A total of 500 school children, age between 6 and 15years were evaluated for HCV seropositivity and interviewed for potential disease risk factors. The seropositivity for Anti-HCV Ab was 2.8%. About 71.4% of seropositive children were 10-15years old. Urban residence, chronic disease, male circumcision and invasive procedures were detected as significant risk factors for acquiring HCV infection among the studied children. The level of awareness of hepatitis C among school children was very low (3.6%) and was correlated with the age and educational level. HCV infection continues to occur in children and is frequently unrecognized. This mandates immediate intervention and robust control strategies in the settings of exposure combined with health education programs to limit further HCV spread.

National prevalence of hepatitis C and B viruses in Mexican blood donors, 2000–2012

IntroductionThe nationwide epidemiological research of transfusion-transmitted diseases is relevant since the information provided by blood banks makes possible the knowledge of the distribution and seroprevalence of diseases, it also allows the indirect verification of the effectiveness of vaccination programs. ObjectiveTo determinate the national seroprevalence of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) in Mexican blood donors in the blood banks registered at the Ministry of Health (SSA) in a 13 year period. Materials and methodsAnalysis of the monthly reports of blood banks (n=555) sent to the National Center of Blood Transfusion (NCBT) and case detection of donors with HBV and HCV positive results (doubly reactive). Additionally, prevalence estimation for each serological marker was performed for the last year (2012) for each state. ResultsA total of 19,096,294 and 18,617,288 monthly reports with results of serological tests for HBV and HCV were respectively found in a period of 13 years (2000–2012). A decrease of 5375 (prevalence=0.47) to 2675 (prevalence=0.15) HBV seropositive cases was observed. The serologic marker for HCV showed an increase of 8170 (prevalence=0.69) to 10,217 (prevalence=0.57) seropositive cases. A higher prevalence was identified for both viruses in the adjacent states of the north border of the countries northern border in the latest report (compared to the national average). ConclusionsA decrease in HBV prevalence to 0.15 in the 13 years period was observed, but the prevalence for HCV marker showed an increase to 0.57, this indicates that HCV remains a potential transfusion transmissible pathogen that needs effective and opportune treatment.

Occurrence and spread of influenza A(H1N1)pdm09 virus infection in Norwegian pig herds based on active serosurveillance from 2010 to 2014.

The incursion of influenza A(H1N1)pdm09 virus was detected by Norway's active serosurveillance of its pig population in 2009. Since then, surveillance data from 2010 to 2014 revealed that 54% of 5643 herd tests involving 1567 pig herds and 28% of 23 036 blood samples screened positive for antibodies against influenza A virus. Positive herds were confirmed to have influenza A(H1N1)pdm09 virus infection by haemagglutination inhibition test. In 50% of positive herd tests, ⩾60% of the sampled pigs in each herd had antibodies against influenza A(H1N1)pdm09 virus. This within-herd animal seroprevalence did not vary for type of production, herd size or year of test. The overall running mean of national herd seroprevalence, and annual herd incidence risks fluctuated narrowly around the means of 45% and 32%, respectively, with the highest levels recorded in the three densest pig-producing counties. The probability of a herd being seropositive varied in the five production classes, which were sow pools, multiplier herds, conventional sow herds, nucleus herds, and fattening herds in descending order of likelihood. Large herds were more likely to be seropositive. Seropositive herds were highly likely to be seropositive the following year. The study shows that influenza A(H1N1)pdm09 virus is established in the Norwegian pig population with recurrent and new herd infections every year with the national herd seroprevalence in 2014 hovering at around 43% (95% confidence interval 40-46%).

Chagas Disease Has Not Been Controlled in Ecuador.

Chagas Disease Has Not Been Controlled in Ecuador.

Using Locally Derived Seroprevalence Data on Measles, Mumps, Rubella, and Varicella by Birth Cohort to Determine Risks for Vaccine-Preventable Diseases During International Travel.

Measles, mumps, rubella, and varicella (MMRV) were common childhood diseases in the United States prior to the introduction of their respective vaccines. Measles was declared eliminated in the United States in 2000. However, 628 cases were reported in 2014, the majority of which have been linked to international travel. The study team set out to investigate the seroprevalence of MMRV in our local population to determine whether such a process can lead to meaningful recommendations for assessing travelers at risk. We conducted a cross-sectional seroprevalence study using a quota sampling method. A total of 460 leftover serum samples were collected from individuals born prior to 1996, who live in the Lehigh Valley region of southeast Pennsylvania. The samples were allocated to five birth-year cohorts, and the seroprevalence of each cohort to MMRV was compared. Additionally, overall seroprevalence of each disease was compared with data from prior national studies. Gender differences within each birth cohort were also assessed. The overall seroprevalence values of measles, mumps, rubella, and varicella were 85.8, 82.8, 96.6, and 97.4%, respectively. There were significant associations between seroprevalence and birth cohort for measles (p = 0.01) as well as mumps (p = 0.037). The overall seroprevalence for our study sample was significantly different from the national seroprevalence results of measles, mumps, and rubella. Our study showed dramatically lower immunity rates for measles and mumps than those shown by prior national seroprevalence studies. The rates in many of the later birth cohorts born after 1966 were significantly lower than the rates reported as necessary to sustain herd immunity. Given that patients' immunization records are not always available or complete, collecting local seroprevalence data may be necessary to more accurately recommend antibody testing and vaccination during pre-travel assessments.

Seroprevalence of Herpes Simplex Virus Type 1 and Type 2 and Coinfection With HIV and Syphilis: The First National Seroprevalence Survey in Saudi Arabia.

Herpes simplex virus (HSV) infection is one of the most common viral infections worldwide. Genital herpes is associated with other sexually transmitted infections (STIs) including HIV. Data on prevalence of HSV infections and other STIs in the Kingdom of Saudi Arabia are limited. We conducted the first national seroprevalence survey to determine the prevalence and epidemiology of HSV infection among adult Saudis and coinfection with other STIs. Serology was used to detect HSV-1, HSV-2, HIV, and syphilis infections among 4985 participants recruited from across the Kingdom. The overall prevalence of HSV-1 and HSV-2 in the enrolled population was 88.8% and 1.26%, respectively. Although not significant for HSV-2, HSV infection was more prevalent among females, those working, and those who were married (married, divorced, or widowed), especially those married at a younger age. Prevalence of both viruses was statistically significantly higher among those with low education and increased with age. Prevalence of Treponema pallidum antibodies and HIV in the sampled population was very low (0.55% and 0.06%, respectively), as was their prevalence among HSV-2-positive participants (1.6% for both). The correlation between HSV-2 infection and other STIs was significant for HIV (P < 0.0001) but not for T. pallidum antibodies (P = 0.25). Herpes simplex virus type 1 infection is highly prevalent in Saudi Arabia and mostly acquired before adulthood. Herpes simplex virus type 2 prevalence is very low, acquired in adulthood, and increased with age. Monitoring the prevalence of HSV infection can help inform targeted strategies to prevent new infections, neonatal transmission, and the spread of other STIs in the Kingdom.

Partner HIV serostatus disclosure and determinants of serodiscordance among prevention of mother to child transmission clients in Nigeria

BackgroundSerodiscordance exists when the known HIV result of one member of a couple pair is positive while that of his/her partner is negative. In sub-Saharan Africa, in stable long-term couple partnerships (married or cohabiting), serodiscordance is a growing source of HIV-transmissions. This study aimed to ascertain across Nigeria, serodiscordance prevalence, partner HIV status disclosure and explore associations between suspected determinants and serodiscordance among PMTCT enrolled HIV positive pregnant women and their partners.MethodsA retrospective Quality of Care performance evaluation was conducted in July 2013 among 544 HIV positive pregnant enrolees of PMTCT services in 62 comprehensive facilities across 5 of Nigeria’s 6 geo-political zones. Data of client-partner pairs were abstracted from pre-existing medical records and analysed using chi-square statistics and logistic regression.ResultsA total of 544 (22 %) of 2499 clients with complete partner details were analysed. Clients’ age ranged from 15 to 50 years with a mean of 30 years. Serodiscordant prevalence was 52 % and chi-square test suggests no significant difference between serodiscordant and seroconcordant clients and their partners (p = 0.265). Serodiscordant rates were closely associated trend wise with national HIV sero-prevalence rates and the median CD4+ count was 425 ul/mm3 (IQR: 290–606 ul/mm3). Similar proportion of clients (99 %) received testing and agreed to disclose status to their partners. Yet, there was no association between clients agreement to disclose HIV status to their partners and these partners getting tested and receiving results (p = 0.919). Significantly, 87 % of clients in concordant HIV positive relationships appeared to be symptomatic (WHO clinical stage 3 or 4) compared to 13 % clients in HIV-discordant relationships (p < 0.003). Client’s age and CD4+ count did not aptly predict serodiscordance (Wald = 0.011 and 0.436 respectively). However, the WHO clinical staging appeared to be a better predictor of serodiscordance and concordance than other variables (Wald = 3.167).ConclusionsThe results suggest that clinical staging (WHO) could be a better predictor of client- partner pair discordant or concordant HIV serostatus. Early partner testing and notification can avert seroconversion, hence properly designed and mainstreamed interventions that target serodiscordant couples are essential.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2155-x) contains supplementary material, which is available to authorized users.

The undiagnosed chronically-infected HCV population in France. Implications for expanded testing recommendations in 2014.

BackgroundRecent HCV therapeutic advances make effective screening crucial for potential HCV eradication. To identify the target population for a possible population-based screening strategy to complement current risk-based testing in France, we aimed to estimate the number of adults with undiagnosed chronic HCV infection and age and gender distribution at two time points: 2004 and 2014.MethodsA model taking into account mortality, HCV incidence and diagnosis rates was applied to the 2004 national seroprevalence survey.ResultsIn 2014, an estimated 74,102 individuals aged 18 to 80 were undiagnosed for chronic HCV infection (plausible interval: 64,920-83,283) compared with 100,868 [95%CI: 58,534-143,202] in 2004. Men aged 18-59 represented approximately half of the undiagnosed population in 2014. The proportion of undiagnosed individuals in 2004 (43%) varied from 21.9% to 74.1% in the 1945-1965 and 1924-1944 birth cohorts. Consequently, age and gender distributions between the chronically-infected (diagnosed and undiagnosed) and undiagnosed HCV populations were different, the 1945-1965 birth cohort representing 48.9% and 24.7%, respectively.ConclusionsMany individuals were still undiagnosed in 2014 despite a marked reduction with respect to 2004. The present work contributed to the 2014 recommendation of a new French complementary screening strategy, consisting in one-time simultaneous HCV, HBV and HIV testing in men aged 18-60. Further studies are needed to assess the cost-effectiveness and feasibility of such a strategy. We also demonstrated that data on the undiagnosed HCV population are crucial to help adapt testing strategies, as the features of the chronically-infected HCV population are very distinct.

An epidemiological assessment towards elimination of rubella and congenital rubella syndrome in Singapore

ObjectiveIn line with regional and global goals for the elimination of rubella and congenital rubella syndrome (CRS), we reviewed the epidemiological situation in Singapore, based on surveillance reports on rubella and CRS, national immunization coverage and seroprevalence surveys. The aim of our review was to identify current gaps and steps taken to achieve the targets set by the World Health Organization (WHO) Western Pacific Regional Office (WPRO). MethodsEpidemiological data on clinical and laboratory-confirmed rubella cases, including CRS, notified to the Communicable Diseases Division, Ministry of Health, Singapore, from 2003 to 2013 were collated and analyzed. Vaccination coverage against rubella was obtained from the National Immunization Registry and School Health Services of the Health Promotion Board. The changing prevalence of rubella was determined from periodic serological surveys. FindingsThe incidence of indigenous rubella cases per million population decreased from 37.2 in 2008 to 7.6 in 2013 and there had been no indigenous case of CRS in 2012 and 2013. Therapeutic abortions performed due to rubella infections had become uncommon. The annual measles, mumps, and rubella (MMR) vaccination coverage in childhood population remained high ranging from 93% to 96%. The overall susceptibility to rubella in women aged 18–44 years had reduced significantly from 15.8% in 2004 to 11.0% in 2010. The prevalence of IgG antibody against rubella among Singapore children aged 1–17 years was maintained at 87.3% in 2008–2010. ConclusionAll available data indicated that Singapore has made good progress towards the elimination of rubella and CRS. It has attained the targets set by the WHO WPRO for 2015. In preparation for verification of rubella elimination, an enhanced surveillance system has been implemented to ensure that all reported cases are laboratory confirmed, and genotyping of rubella virus strains isolated is carried out to provide evidence for interruption of endemic transmission.

A national survey to determine prevalence of Trypanosoma cruzi infection among pregnant women in Ecuador.

A nationwide survey was conducted to obtain an estimate of Chagas disease prevalence among pregnant women in Ecuador. As part of a national probability sample, 5,420 women seeking care for delivery or miscarriage at 15 healthcare facilities were recruited into the study. A small minority of participants reported knowing about Chagas disease or recognized the vector. A national seroprevalence of 0.1% (95% confidence interval [95% CI] = 0.0-0.2%) was found; cases were concentrated in the coastal region (seroprevalence = 0.2%; 95% CI = 0.0-0.4%). No cases of transmission to neonates were identified in the sample. Seropositive participants were referred to the National Chagas Program for evaluation and treatment. Additional studies are necessary to determine if areas of higher prevalence exist in well-known endemic provinces and guide the development of a national strategy for elimination of mother-to-child transmission of Chagas disease in Ecuador.