Prevalence of chronic infections and susceptibility to measles and varicella-zoster virus in Latin American immigrants

The immune status of migrant populations in Europe and implications for vaccine-preventable disease control: a systematic review and meta-analysis

BACKGROUND

Ensuring vaccination coverage reaches established herd immunity thresholds (HITs) is the cornerstone of any vaccination programme. Diverse migrant populations in European countries have been associated with cases of vaccine-preventable diseases (VPDs) and outbreaks, yet it is not clear to what extent they are an under-immunized group.

METHODS

We did a systematic review and meta-analysis to synthesize peer-reviewed published primary research reporting data on the immune status of migrants in EU/EEA countries, the UK and Switzerland, calculating their pooled immunity coverage for measles, mumps, rubella and diphtheria using random-effects models. We searched on Web of Science, Embase, Global Health and MEDLINE (1 January 2000 to 10 June 2022), with no language restrictions. The protocol is registered with PROSPERO (CRD42018103666).

FINDINGS

Of 1103 abstracts screened, 62 met eligibility criteria, of which 39 were included in the meta-analysis. The meta-analysis included 75 089 migrants, predominantly from outside Europe. Pooled immunity coverage among migrant populations was well below the recommended HIT for diphtheria (n = 7, 57.4% [95% confidence interval (CI): 43.1-71.7%] I2 = 99% vs HIT 83-86%), measles (n = 21, 83.7% [95% CI: 79.2-88.2] I2 = 99% vs HIT 93-95%) and mumps (n = 8, 67.1% [95% CI: 50.6-83.6] I2 = 99% vs HIT 88-93%) and midway for rubella (n = 29, 85.6% [95% CI: 83.1-88.1%] I2 = 99% vs HIT 83-94%), with high heterogeneity across studies.

INTERPRETATION

Migrants in Europe are an under-immunized group for a range of important VPDs, with this study reinforcing the importance of engaging children, adolescents and adults in 'catch-up' vaccination initiatives on arrival for vaccines, doses and boosters they may have missed in their home countries. Co-designing strategies to strengthen catch-up vaccination across the life course in under-immunized groups is an important next step if we are to meet European and global targets for VPD elimination and control and ensure vaccine equity.

Infectious diseases in post-trial detention and comparisons with pre-trial detention: A study in Geneva, Switzerland

BACKGROUND

Prevalence rates of infectious diseases in post-trial prisons have been scarcely investigated. Due to the specific characteristics of these prison populations, these prevalence rates may differ from pre-trial prisons and more information is needed for developing adequate prevention and treatment interventions. This study compared prevalence rates of hepatitis B virus (HBV), hepatitis C virus (HCV), susceptibility to varicella zoster virus (VZV) and measles in pre- and post-trial detention.

METHODS

Data were collected in Geneva post-trial prisons among males (n=250), including serological tests, demographics, and risk factors, and were compared to those of the Geneva pre-trial prison (n=273).

RESULTS AND CONCLUSIONS

Incarcerated men in post-trial detention shared a disproportionate burden of infectious diseases compared to community (chronic HBV: 5.9%, HVC: 2.8%, susceptibility to VZV: 5.9%, to measles: 4.7%). Susceptibility to VZV and prevalence rate of HCV were lower in post-trial prisons (p=.034 and p=.080). Prevalence rates of infectious diseases in prison should be interpreted in light of the prison population's characteristics. Screening and treatment should be promoted in all types of prison settings. Since overcrowding and turnover of pre-trial prisons restrict the access to screening, prevention and treatment of infectious diseases, interventions are crucial in post-trial prisons.

Health of undocumented migrants in primary care in Switzerland

Background

Undocumented migrants endure adverse living conditions while facing barriers to access healthcare. Evidence is lacking regarding their healthcare needs, notably in regards to chronic diseases. Our goal was to investigate health conditions in undocumented migrants attended in primary care setting.

Methods

This study was conducted at the primary care outpatient clinic, Geneva University Hospitals, Switzerland. We retrospectively recorded and coded all medical conditions of a random sample of 731 undocumented migrants using the International Classification of Primary Care, 2nd version (ICPC-2). We dichotomized conditions as chronic or non-chronic and considered multimorbidity in the presence of three or more chronic conditions.

Results

Participants originated from 72 countries and were mainly female (65.5%) with a mean age of 42.4 (standard deviation [SD]: 11.4) years. They presented a mean of 2.9 (SD: 2.1; range: 1–17) health conditions. In multivariable analysis, the number of conditions was associated with female gender (p = 0.011) and older age (p <0.001), but not with origin (p = 0.373). The body systems most frequently affected were endocrine, metabolic and nutritional (n = 386; 18.4%), musculoskeletal (n = 308, 14.7%) and digestive (n = 266, 12.8%). Hypertension (17.9%; 95% CI: 15.2%, 29.9%), obesity or overweight (16%; 95% CI: 13.4%, 18.9%) and gastric problems (14.1%; 95% CI: 11.6%, 16.8%) were most prevalent. Overall, 71.8% (95% CI: 68.5%, 75%) participants had at least one chronic condition while 20% (95% CI: 17.2%, 23.1%) had three or more. In multivariable analysis, age (p <0.001) was the only predictor of presenting at least one or three or more chronic conditions.

Conclusions

Undocumented migrants present multiple health problems in primary care settings and bear an important burden of chronic diseases. The extent of multimorbidity highlights the need to provide and facilitate the access to comprehensive and long-term primary healthcare services.

Strongyloides stercoralis infection increases the likelihood to detect Trypanosoma cruzi DNA in peripheral blood in Chagas disease patients

OBJECTIVES

In a previous study performed by our group, Strongyloides stercoralis infection in patients with Chagas disease was associated with higher proportion of Trypanosoma cruzi DNA detection in peripheral blood. The aim of the study was to confirm this association in a larger cohort of patients.

METHODS

Cross-sectional study of all patients with Chagas disease diagnosed from 2005 to 2015 during blood donation at the Catalan Blood Bank. Demographic data and T. cruzi RT-PCR were collected. S. stercoralis infection diagnosis was based on a serological test.

RESULTS

Two hundred and two blood donors were included. T. cruzi RT-PCR was positive in 72 (35.6%) patients, and S. stercoralis serology was positive in 22 (10.9%) patients. Patients with positive S. stercoralis serology had higher proportion of positive T. cruzi RT-PCR than those with negative serology (54.5% vs. 33.3%, P = 0.050), and the difference increased when taking a serological index cut-off of 2.5, which increases the specificity of the test to detect a confirmed strongyloidiasis (60% vs. 33%, P = 0.017).

CONCLUSIONS

Patients with Chagas disease with positive S. stercoralis serology had higher proportion of positive T. cruzi RT-PCR in peripheral blood than those with negative serology, which reflects the potential immunomodulatory effects of S. stercoralis in T. cruzi co-infected patients.

Seroepidemiological trend of strongyloidiasis in the Bolivian Chaco (1987-2013) in the absence of disease-specific control measures

OBJECTIVES

The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013.

METHODS

Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland).

RESULTS

Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987.

CONCLUSIONS

The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections.