Characterization of hepatitis virus co-infections in a cohort of immigrants living in southern Italy.

To characterize viral hepatitis co-infections in a cohort of immigrants living in southern Italy. In a prospective multicenter study, all undocumented immigrants and low-income refugees consecutively evaluated for a clinical consultation at one of the five first-level clinical centers in southern Italy from January 2012 to February 2020 were enrolled. All subjects included in the study were screened for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV) and anti-HIV; the HBsAg-positive were screened also for anti-delta. Of the 2923 subjects enrolled, 257 (8%) were HBsAg-positive alone (Control group B), 85 (2.9%) only anti-HCV-positive (Control group C), 16 (0.5%) HBsAg/anti-HCV-positive (Case group BC), and 8 (0.2%) HBsAg/anti-HDV-positive (Case group BD). Moreover, 57 (1.9%) subjects were anti-HIV-positive. HBV-DNA positivity was found less frequently in the 16 subjects in Case group BC (43%) and in the 8 in Case group BD (12.5%) than in the 257 in Control group B (76%; p = 0.03 and 0.0000, respectively). Similarly, HCV-RNA positivity was more frequent in Case group BC than in Control group C (75% vs. 44.7% p = 0.02). The subjects in Group BC had a lower prevalence of asymptomatic liver disease (12.5%) than Control group B (62.2%, p = 0.0001) and Control group C (62.3%, p = 0.0002). Conversely, liver cirrhosis was more frequently identified in Case group BC (25%) than in Control groups B and C (3.11% and 2.35%, p = 0.0000 and 0.0004, respectively). The present study contributes to the characterization of hepatitis virus co-infections in the immigrant population.

Hepatitis D virus infection in a large cohort of immigrants in southern Italy: a multicenter, prospective study.

BACKGROUND: Since few data are available in the literature on the prevalence of anti-Delta-positive subjects in immigrant populations, the aim of the present study was to evaluate the demographic and virological characteristics of HDV infection in a large cohort of immigrants living in southern Italy. METHODS: Between January 2012 and February 2020 all immigrants attending one of the 5 first- level centers were enrolled and screened for HBsAg, the HBsAg-positive for anti-Delta and if positive, for HDV-RNA and HDV genotype. RESULTS: Of the 3521 immigrants observed in the study period, 3417 (97.0%) agreed to be screened; they were mainly males (61%), with a median age of 27 years (IQR 8-74) and came prevalently (58%) from sub-Saharan Africa. Of the 3417 patients enrolled, 319 (9%) subjects were HBsAg-positive, and of those, 8 (2.5%) were anti-Delta-positive. No difference in the demographic and epidemiological characteristics was observed between the anti-Delta-negative vs -positive. Of the 8 anti-Delta-positive subjects, only one was HDV-RNA-positive (viral load: 7050 IU/mL), genotype 1, with clinical signs of cirrhosis. CONCLUSIONS: the present study showed a prevalence of HDV of 2.5% in a large cohort of asymptomatic immigrants, suggesting the need for screening campaigns for viral infections including delta hepatitis in this population.

Correction to: HBV molecular epidemiology and clinical condition of immigrants living in Italy.

The original version of this article unfortunately contained a mistake. The name of the author Mara Caroprese was rendered wrongly. The correct name is shown above.

Occult Hepatitis B Infection in Recent Immigrants to Italy: Occult B Infection in Immigrants.

This study determined the prevalence and clinical features of occult hepatitis B infection (OBI) in a population of recent immigrants to Italy. Two hundred-five immigrants were tested for HBV-infection and were classified as seropositive-OBI or false-OBI. Biochemical/virological activities and imaging diagnostics were determined in anti-HBc-positive subjects. Among the tested subjects, 39.0% were anti-HBc-positive/HBsAg-negative; 11.2% had persistently normal ALT levels with mild detectable HBV-DNA, seropositive-OBI; 6.2% had slightly elevated ALT and positive serum HBV-DNA with a mean level of viral load: 3275 copies/mL-false-OBI. The total prevalence of OBI was 6.8%; 4.4% were seropositive-OBI and 2.4% were false-OBI. Diagnosis by echo-tomography was achieved in 35.7% OBI subjects with alterations of the hepatic echo-texture. We found a moderate prevalence of occult hepatitis B-infection in immigrants. Frequently, these subjects present false-OBI.

HBV molecular epidemiology and clinical condition of immigrants living in Italy.

INTRODUCTION: We investigated 170 HBsAg-positive immigrants living in Italy for 1-7 years to ascertain whether they may have become infected in the host country. METHODS: Of 2032 adult immigrants interviewed, 1727 (85%) voluntarily adhered to a screening program for bloodborne or sexually transmitted infections. HBsAg was detected in 170 (9.8%) screened immigrants who completed the diagnostic, clinical and therapeutic process at the nearest clinic of infectious diseases. HBV molecular biology was performed applying a homemade technology. Phylogenetic signal of the datasets was obtained by a likelihood-mapping analysis using TreePuzzle. RESULTS: Of the 170 HBsAg-positive immigrants, 133 were inactive carriers, 29 had chronic hepatitis and 8 compensated cirrhosis. HBV genotype was identified in 109 of the 113 HBV-DNA-positive immigrants and HBV-genotype-E predominated (68.9%). Of these 109, 6 (5.5%) subjects showed an HBV genotype absent or extremely rare in their native country: HBV-genotype-E in three from Eastern Europe and in one from Sri Lanka, possibly acquired from other immigrants from sub-Saharan countries, HBV-genotype-D1 in one from Burkina Faso and one from Senegal, possibly acquired in Italy. CONCLUSION: The data suggest that immigrants may acquire HBV infection in Italy and, therefore, HBV vaccination programs should be extended to all immigrants living in Italy.

Clinical Findings of HCV Chronic Infection in Undocumented Immigrants and Low-Income Refugees in Three Areas of Southern Italy.

INTRODUCTION AND AIM: In recent decades, Italy has become a land of immigration from countries suffering a socio-economic crisis. The aim of this study was to perform an organized screening to identify and offer care to immigrants with HCV infection. MATERIAL AND METHODS: The screening, performed from 2012 to 2015, involved 1,727 immigrants in the Campania and Apulia regions in southern Italy. RESULTS: Screening was accepted by 1,727 (85%) out of 2,032 immigrants interviewed; 70 (4.1%) of the 1,727 were anti-HCV-positive, all unaware of their serological condition, 31 (44.3%) of whom were HCV-RNA-positive and 39 negative. The 31 HCV-RNA-positive immigrants were further investigated at a third-level clinic of infectious diseases. The HCV viral load was 2.6 x 107 ± 7.7 x107 IU/mL, and 35.5% showed HCV-genotype 1a or 1b, 23.8% genotype 2 and 22.6% genotype 3. Two immigrants had liver cirrhosis and, in accordance with the Italian Healthcare Authority guidelines, received an interferon-free regimen and achieved a sustained virological response (SVR); 18 had chronic hepatitis, 6 of whom with a high risk of progression and received interferonbased therapy, with SVR in 4, whereas 12 at low risk were put on a waiting list for future interferon-free treatment, once licensed. The remaining 11 HCV-RNA-positive immigrants were considered HCV inactive chronic carriers and were included in a long-term observational program. CONCLUSION: The screening program can be considered successful since it was accepted by 85% of the subjects interviewed and identified 70 anti-HCV-positive immigrants, all unaware of their clinical and virological condition.

Chronic HBV infection in pregnant immigrants: a multicenter study of the Italian Society of Infectious and Tropical Diseases.

The aims of the study were to estimate the clinical impact of HBV infection in pregnant immigrants and their family members and to identify a useful approach to managing the healthcare of HBsAg-positive immigrants. Included in this study were 143 HBsAg-positive pregnant immigrants of the 1,970 from countries with intermediate/high HBV endemicity who delivered in 8 Italian hospitals in 2012-2013. In addition, 172 family members of 96 HBsAg-positive pregnant immigrants were tested for serum HBsAg. The median age of the 143 HBsAg-positive pregnant immigrants was 31.0±12.1 years and the length of stay in Italy 5.0±4.1 years; 56.5% were unaware of their HBsAg positivity. HBV DNA was detected in 74.5% of the pregnant immigrants, i.e., 94.3% from Eastern Europe, 72.2% from East Asia and 58.1% from Sub-Saharan Africa. HBV DNA ≥2000 IU/mL was detected in 47.8% of pregnant immigrants, associated with ALT ≥1.5 times the upper normal value in 15% of cases. Anti-HDV was detected in 10% of cases. HBsAg was detected in 31.3% of the 172 family members. All HBsAg-positive immigrants received counseling on HBV infection and its prevention, and underwent a complete clinical evaluation. The findings validate the approach used for the healthcare management of the HBsAg-positive immigrant population.

Prevalence of antibodies to hepatitis E virus in immigrants: a seroepidemiological survey in the district of Foggia (Apulia-southern Italy).

Hepatitis E virus (HEV) is the etiologic agent of endemically transmitted viral hepatitis. HEV is endemic in developing countries where it occurs in sporadic and endemic forms, but autochthonous sporadic cases of hepatitis E have been reported in North America and in Europe, including Italy. The aim of the present study was to assess the seroprevalence of antibodies to HEV in immigrants from developing countries to the province of Foggia. The seroprevalence of HEV was determined in a cohort of 412 immigrants (mostly from countries in sub-Saharan Africa) who had arrived recently in Italy. Serum samples were tested for anti-HEV by a commercial enzyme immunoassay (EIA) based on recombinant proteins; positive results were confirmed by a Western blot assay (Recomblot HEV). A total of 88 (21.3%) of the 412 serum samples examined were reactive to IgG anti-HEV. Eighty-one of these samples (19.7%) were confirmed by Western blot. Anti-HEV IgM was found in 34/81 subjects (41.9%) of the anti-HEV IgG positive serum samples. Almost all anti-HEV positive subjects were asymptomatic clinically, but alanine aminotransferase serum values were elevated in 28/34 (82.3%) patients with IgM anti-HEV-positive. The results of this study indicate high circulation of HEV in the immigrant population. The high prevalence of acute hepatitis involved mainly subjects who arrived in Italy during the same period from the same countries (Eritrea, Ethiopia, and Somalia).

Congenital Zika Virus Syndrome: Microcephaly and Orofacial Anomalies.

The progressive reappearance of Zika virus (ZIKV) infections since October 2013 and its circulation in >70 countries and territories (from French Polynesia to Brazil and other countries in the Americas, with sporadic spread in Europe and the East) has long been reported as a global public health emergency. ZIKV is a virus transmitted by arthropods (arboviruses), mainly by Aedes mosquitoes. ZIKV can also be transmitted to humans through mechanisms other than vector infection such as sexual intercourse, blood transfusions, and mother-to-child transmission. The latter mode of transmission can give rise to a severe clinical form called congenital Zika syndrome (CZS), which can result in spontaneous abortion or serious pathological alterations in the fetus such as microcephaly or neurological and orofacial anomalies. In this study, beside a succinct overview of the etiological, microbiological, and epidemiological aspects and modes of transmission of Zika virus infections, we have focused our attention on the pathogenetic and histopathological aspects in pregnancy and the pathogenetic and molecular mechanisms that can determine microcephaly, and consequently the clinical alterations, typical of the fetus and newborns, in a subject affected by CZS.

COVID-19 and Oral Lichen Planus: Between an "Intriguing Plot" and the "Fata Morgana Effect".

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to significant morbidity and mortality worldwide since its declaration as a global pandemic in March 2020. Alongside the typical respiratory symptoms, unusual clinical manifestations such as oral lichen planus (OLP) have been observed. OLP is a chronic inflammatory mucocutaneous dermatosis that results from a cell-mediated reaction, and its pathogenesis involves the loss of immunological tolerance. OLP has been associated with several triggering factors, such as certain drugs, stress, smoking, and even some viruses. Exposure to the spike protein antigen of SARS-CoV-2 during an infection can trigger autoimmune reactions and lead to the onset or flare of OLP. The E3 protein ligase TRIM21, which is identified in the lamina propria of OLP lesions, is overexpressed in COVID-19 patients and plays a critical role in autoimmune pathologies. Furthermore, the psychological stress of the lockdown and quarantine can be a trigger for the onset or exacerbation of OLP. However, the diagnosis of OLP is complex and requires a biopsy in order to confirm a clinical diagnosis, rule out other pathologies, and establish the most appropriate therapeutic procedure. Further research is needed to understand the potential link between Co-19 and OLP.

HBV DNA suppression and HBsAg clearance in HBeAg negative chronic hepatitis B patients on lamivudine therapy for over 5 years.

BACKGROUND & AIMS: In long-term responder patients, it is unclear whether lamivudine (LAM) monotherapy should be continued or switched to a high-genetic-barrier analogue. This study aims at assessing LAM efficacy over a 5-year period and the residual risk of drug resistance. The rate of HBsAg clearance and LAM long-term safety profile were also evaluated. METHODS: One hundred and ninety-one patients with chronic HBeAg-negative hepatitis B successfully treated with LAM monotherapy for at least 5 years were included. Biochemical and virological tests were assessed every 3 months in all patients and HBsAg quantification was performed in 45/191. Reverse-transcriptase (RT) region was directly sequenced in virological breakthrough patients. RESULTS: One hundred and ninety-one patients (148 males, median age 53 years, 72 with compensated cirrhosis) responding to 60-month LAM monotherapy continued to receive LAM monotherapy beyond the initial 5 years and were followed for an additional 36-month median period (range 1-108). Virological response was maintained in 128/191 patients (67%) and HBsAg clearance was observed in 15/128 (11.7%) after a 32-month median period (range 1-65). The 63 remaining patients (33%) showed virological breakthrough after a 15-month median treatment (range 1-78). RT region analysis was performed in 38/63 breakthrough patients and LAM resistant mutations were found in 37/38. No significant side effects were observed. CONCLUSIONS: In long-term responder patients, continuation of LAM monotherapy resulted in persistent viral suppression in most cases with undetectable HBV DNA by real-time PCR; moreover, 11.7% of these patients cleared HBsAg. Selection of LAM resistance, however, can still occur even after successful long-term therapy, thus emphasising the importance of a careful virological monitoring.

SARS-CoV-2 Infection and Taste Alteration: An Overview.

Since the worldwide spread of SARS-CoV-2 infection, the management of COVID-19 has been a challenge for healthcare professionals. Although the respiratory system has primarily been affected with symptoms ranging from mild pneumonia to acute respiratory distress syndrome, other organs or systems have also been targets of the virus. The mouth represents an important route of entry for SARS-CoV-2. Cells in the oral epithelium, taste buds, and minor and major salivary glands express cellular entry factors for the virus, such as ACE2, TMPRSS2 and Furin. This leads to symptoms such as deterioration of taste, salivary dysfunction, mucosal ulcers, before systemic manifestation of the disease. In this review we report and discuss the prevalence and socio-demographics of taste disturbances in COVID-19 patients, analysing the current international data. Importantly, we also take stock of the various hypothesized pathogenetic mechanisms and their impact on the reported symptoms. The literature indicated that COVID-19 patients frequently present with gustatory dysfunction, whose prevalence varies by country, age and sex. Furthermore, this dysfunction also has a variable duration in relation to the severity of the disease. The pathogenetic action is intricately linked to viral action which can be expressed in several ways. However, in many cases these are only hypotheses that need further confirmation.

Individualized treatment with combination of Peg-interferon alpha 2b and ribavirin in patients infected with HCV genotype 3.

BACKGROUND & AIMS: The benefit of individualizing treatment for patients with genotype 3 HCV infection on the basis of viral clearance at week 4 (wk4-R) has not been firmly established. METHODS: Four hundred and fourteen patients received Peg-interferon alpha-2b plus 1000-1200 mg of ribavirin daily according with body weight > or <75 kg. Patients were randomized to standard 24 weeks (Std24) or to a 12 or 36 weeks variable treatment duration (Var12/36). In the variable treatment arm, patients with or without wk4-R were allocated to either 12 or 36 weeks duration. RESULTS: At treatment week 4, HCV RNA was undetectable in 262 patients (63.3%), 136 in the Std24, and 126 in the Var12/36 group (p=0.41). In patients with wk4-R, end-of-treatment (EOT) responses were 80.4% (CI 85.4-95.3) and 97.6% (CI 94.9-99.9) in the two arms, respectively (p=0.019). In patients without wk4-R, corresponding rates were 61.9% (50.6-73.2) and 75.3% (CI 65.9-84.6) (p=0.08). SVR was attained in 302 patients, 71.4% (CI 65.3-77.6) in the St24 group and 74.3% (CI 58.4-80.3) in the variable 12/36 arm. Among patients with wk4-R, SVR was 81.6% (CI 75.1-88.1) and 82.5% (75.9-89.1), respectively. In patients without wk4-R, SVR amounted to 52.1% (CI 40.4-63.7) and 61.7 (CI 51.1-72.3) in the two arms (p=0.25). CONCLUSIONS: HCV genotype 3 patients with week4-R may be treated safely with 12 weeks of therapy, provided that sufficiently high doses of ribavirin are administered. For patients still viremic at treatment week 4, SVR rates were numerically higher after 36 weeks of treatment than after the currently recommended 24 weeks.

Determinants of relapse after a short (12 weeks) course of antiviral therapy and re-treatment efficacy of a prolonged course in patients with chronic hepatitis C virus genotype 2 or 3 infection.

UNLABELLED: In hepatitis C virus (HCV) genotypes 2 and 3 patients, the high rate of relapse after 12 to 16 weeks of antiviral therapy is the main concern for shortening treatment duration. This study was undertaken to delineate predictors of relapse after short treatment in patients with undetectable HCV RNA at treatment week 4 (RVR), and to report in RVR patients with relapse the sustained virological response (SVR) after a second 24-week course of therapy. RVR patients received pegylated interferon (Peg-IFN) alfa-2b (1.5 microg/kg) and ribavirin (1000-1200 mg/day) for 12 weeks; those who relapsed were re-treated with the same drug doses but for the extended standard duration of 24 weeks. Logistic regression analysis was applied to delineate predictors of relapse by using age, sex, route of transmission, body mass index (BMI), serum alanine aminotransferase (ALT), HCV genotypes, serum HCV RNA levels, and platelet counts as covariates. Of 718 patients with genotypes 2 and 3 who were started on therapy, 496 (69.1%) had undetectable HCV RNA at week 4. Of them, 409 patients (82.5%, CI 79.1-85.8) attained SVR, and 67 (14.1%, CI 10.4-16.5) relapsed. At regression analysis, only platelet count less than 140,000 mm(3) [odds ratio, 2.51; confidence interval (CI), 1.49-4.20] and BMI 30 or higher (odds ratio, 1.7; CI, 1.03-2.70) were independently associated with relapse. Forty-three of 67 patients with relapse agreed to be re-treated, and an SVR was achieved in 30 (70.0%) of them. CONCLUSION: We recommend 12 weeks course of therapy for patients with undetectable HCV RNA at treatment week 4, providing they present with no advanced fibrosis and low BMI.

[Prevalence of Plasmodium spp. in asymptomatic African immigrants assessed by nucleic acid sequence based amplification]. / Rilievo di Plasmodium spp. in immigrati asintomatici mediante tecniche molecolari innovative (NASBA) e valutazione del rischio.

Malaria is one of the most important infectious diseases in the world. Although most cases occur in the tropical regions of Africa, Asia, Central and South America, there is in Europe a significant increase in the number of imported cases in non-endemic countries, in particular due to the higher mobility in today's society. The prevalence of a possible asymptomatic infection with Plasmodium species was assessed using Nucleic Acid Sequence Based Amplification (NASBA) assays on clinical samples collected from 195 study cases with no clinical signs related to malaria and coming from sub-Saharan Africa. In addition, base-line demographic, clinical and socio-economic information was collected from study participants who also underwent a full clinical examination. Sixty-two study subjects (31.8%) were found positive for Plasmodium using a pan Plasmodium specific NASBA based on the small subunit 18S rRNA gene (18S NASBA). Twenty-four samples (38%) of the 62 positive study cases were found positive with a Pfs25 mRNA NASBA, which specifically detects gametocytes of Plasmodium falciparum. This study showed that a substantial proportion of people originating from malaria endemic countries harbour malaria parasites in their blood. If transmission conditions are available, they could be a reservoir.

Blood-borne chronic viral infections in a large cohort of immigrants in southern Italy: A seven-centre, prospective, screening study.

BACKGROUND: Aim of this study was to evaluate the prevalence of blood-borne chronic viral infections in immigrants living in southern Italy and identify factors associated to viral infections. METHODS: A prospective screening program was performed in seven clinical centers operating in Campania, Apulia and Calabria regions in southern Italy, in order to identify immigrants with HBV, HCV or HIV infections. RESULTS: Of 4,125 immigrants observed in the study period, 3,839 (93.0%) agreed to be screened: 381 (9.9%) resulted HBsAg-positive, 136 (3.5%) anti-HCV, 62 (1.6%) anti-HIV and 1,448 (37.7%) HBsAg-negative and anti-HBc-positive. Ongoing or previous HBV infection was observed more frequently in males (p = 0.02 and p < 0.001, respectively), whereas HIV infection in females (p = 0.01). Immigrants from western Africa showed a higher rate of HBsAg positivity (p < 0.0001), HBsAg negativity/anti-HBc positivity (p < 0.0001) and anti-HIV positivity (p = 0.004) compared with those from other geographical areas. At multivariate analysis, ongoing HBV infection was associated with male sex (OR 1.49, 95% CI: 1.04-2.14) and origin from western Africa (OR 4.67, 95% CI: 1.70-12.80) and eastern Europe (OR 3.44, 95% CI: 1.17-10.08). HCV infection showed the tendency to be more frequent among males (OR 1.84, 95% CI: 0.99-3.42). HIV infection was associated with an older age (OR 1.04, 95% CI: 1.01-1.06), origin from western Africa (OR 4.09, 95% CI: 1.26-13.29) and female sex (OR 2.38, 95% CI: 1.29-4,39; p = 0.006). CONCLUSIONS: The high prevalence of HBV, HCV and HIV infections in our large cohort of immigrants should definitively prompt Italian Healthcare Authorities to develop adequate cost-effective screening policies.

Individualized treatment duration for hepatitis C genotype 1 patients: A randomized controlled trial.

UNLABELLED: It was hypothesized that in hepatitis C virus (HCV) genotype 1 patients, variable treatment duration individualized by first undetectable HCV RNA is as effective as standard 48-week treatment. Patients (n = 696) received peginterferon alfa-2a, 180 mg/week, or peginterferon alfa-2b, 1.5 mg/kg/week, plus ribavirin, 1000-1200 mg/day, for 48 weeks (standard, n = 237) or for 24, 48, or 72 weeks if HCV-RNA-negative at weeks 4, 8, or 12, respectively (variable, n = 459). Sustained virologic response (SVR) was achieved in 45.1% [95% confidence interval (CI) 38.8-51.4] of the patients in the standard group and in 48.8% (CI 44.2-53.3) of the patients in the variable group (P = 0.37). The percentages of patients who first achieved undetectable HCV RNA at weeks 4, 8, or 12 were 26.7%, 27.8%, and 11.3%, respectively. In the standard treatment group, 87.1%, 70.3%, and 38.1% of patients who first achieved undetectable HCV RNA at 4, 8, or 12 weeks attained SVRs, respectively. In the variable group, corresponding SVR rates were 77.2%, 71.9%, and 63.5%. Low viremia levels and young age were independent predictors of response at week 4 [rapid virologic response (RVR)]. RVR patients with baseline viremia >or=400,000 IU/mL achieved higher SVR rates when treated for 48 weeks rather than 24 weeks (86.8% versus 73.1%, P = 0.14). The only predictive factor of SVR in RVR patients was advanced fibrosis. CONCLUSION: Variable treatment duration ensures SVR rates similar to those of standard treatment duration, sparing unnecessary side effects and costs.

Prevalence of Plasmodium spp. in malaria asymptomatic African migrants assessed by nucleic acid sequence based amplification.

BACKGROUND: Malaria is one of the most important infectious diseases in the world. Although most cases are found distributed in the tropical regions of Africa, Asia, Central and South Americas, there is in Europe a significant increase in the number of imported cases in non-endemic countries, in particular due to the higher mobility in today's society. METHODS: The prevalence of a possible asymptomatic infection with Plasmodium species was assessed using Nucleic Acid Sequence Based Amplification (NASBA) assays on clinical samples collected from 195 study cases with no clinical signs related to malaria and coming from sub-Saharan African regions to Southern Italy. In addition, base-line demographic, clinical and socio-economic information was collected from study participants who also underwent a full clinical examination. RESULTS: Sixty-two study subjects (31.8%) were found positive for Plasmodium using a pan Plasmodium specific NASBA which can detect all four Plasmodium species causing human disease, based on the small subunit 18S rRNA gene (18S NASBA). Twenty-four samples (38%) of the 62 18S NASBA positive study cases were found positive with a Pfs25 mRNA NASBA, which is specific for the detection of gametocytes of Plasmodium falciparum. A statistically significant association was observed between 18S NASBA positivity and splenomegaly, hepatomegaly and leukopaenia and country of origin. CONCLUSION: This study showed that a substantial proportion of people originating from malaria endemic countries harbor malaria parasites in their blood. If transmission conditions are available, they could potentially be a reservoir. Therefore, health authorities should pay special attention to the health of this potential risk group and aim to improve their health conditions.