Evaluation of immune responses to combined hepatitis A and B vaccine in HIV-infected children and children on immunosuppressive medication.

OBJECTIVE: A phase IV interventional study with a combined hepatitis A and B vaccine was conducted in HIV-infected children and children receiving immunosuppressive medication for treatment of rheumatic diseases to evaluate immune responses. METHODS: Both groups (1-16 years of age) received combined (inactivated) HAV and (rDNA) HBV vaccine Ambirix(®) at months 0 and 6. Serum samples were taken at four time points and tested for anti-HAV and anti-HBs antibodies. Anti-HAV concentrations ≥20 mIU/mL or anti-HBs concentrations ≥10 mIU/mL were considered protective. Seropositivity percentages were calculated and geometric mean concentrations (GMCs) were compared by nonparametric Mann-Whitney U-test or Kruskal-Wallis one-way-analysis-of-variance. RESULTS: Of 80 HIV-infected children who completed the study, 67 were HAV-susceptible and 68 HBV-susceptible at enrolment. Of 80 children with rheumatic diseases who completed the study, 65 were HAV-susceptible and 74 HBV-susceptible at enrolment. Immune responses to HAV after first dose of vaccine in both study groups were low: 71% and 55% respectively, whereas immune responses after the second dose were 99% and 100% respectively. Immune response to HBV after first dose of vaccine in both groups was also low: 27% and 17% respectively. Immune responses after the second dose were 97% and 93%, respectively. A larger proportion of children on combination antiretroviral therapy (cART) and of children with viral load <50 copies/mL responded to HBV, and also showed a significantly higher GMC. CONCLUSIONS: Although immune response after full series of combined HAV and HBV vaccine in both groups was excellent and comparable to healthy children, a substantial proportion of both groups was not protected for HAV after first dose of vaccine. This protection gap is especially important for HAV in travel health and postexposure prophylactic treatment: both groups of children should be serologically tested for anti-HAV prior to travel to ensure protection if there is no time to await second dose of vaccine.

Symptoms of infectious diseases in immunocompromised travelers: a prospective study with matched controls.

BACKGROUND: Immunocompromised travelers to developing countries are thought to have symptomatic infectious diseases more often and longer than non-immunocompromised travelers. Evidence for this is lacking. This study evaluates whether immunocompromised short-term travelers are at increased risk of diseases. METHODS: A prospective study was performed between October 2003 and May 2010 among adult travelers using immunosuppressive agents (ISA) and travelers with inflammatory bowel disease (IBD), with their non-immunocompromised travel companions serving as matched controls with comparable exposure to infection. Data on symptoms of infectious diseases were recorded by using a structured diary. RESULTS: Among 75 ISA, the incidence of travel-related diarrhea was 0.76 per person-month, and the number of symptomatic days 1.32 per month. For their 75 controls, figures were 0.66 and 1.50, respectively (p > 0.05). Among 71 IBD, the incidence was 1.19, and the number of symptomatic days was 2.48. For their 71 controls, figures were 0.73 and 1.31, respectively (p > 0.05). These differences also existed before travel. ISA had significantly more and longer travel-related signs of skin infection and IBD suffered more and longer from vomiting. As for other symptoms, no significant travel-related differences were found. Only 21% of immunocompromised travelers suffering from diarrhea used their stand-by antibiotics. CONCLUSIONS: ISA and IBD did not have symptomatic infectious diseases more often or longer than non-immunocompromised travelers, except for signs of travel-related skin infection among ISA. Routine prescription of stand-by antibiotics for these immunocompromised travelers to areas with good health facilities is probably not more useful than for healthy travelers.

Hepatitis C in the general population of various ethnic origins living in the Netherlands: should non-Western migrants be screened?

BACKGROUND & AIMS: Little is known about the HCV prevalence in non-Western migrant populations. To determine whether targeted HCV screening and prevention programs for migrants are needed, we examined HCV prevalence and determinants among non-Western, Western migrants, and the native Dutch population in the Netherlands. METHODS: Data were obtained from four surveys: (1) 3895 heterosexual visitors recruited during biannual surveys at the STI-clinic Amsterdam, 2007-2009; (2) random sample of 4563 pregnant women in Amsterdam, 2003; (3) population-based random sample of 1309 inhabitants of Amsterdam, 2004; (4) population-based random sample of 4428 people living in the Netherlands, 2006-2007. Characteristics associated with HCV-positivity were examined and phylogenetic analysis was used to obtain insight in the geographical origin of HCV strains. RESULTS: HCV seroprevalence in the four surveys was low (0.3-0.6%). In total 4860/14,195 (34%) were non-Western and 9329/14,195 (66%) Western participants (including Dutch). First-generation non-Western migrants were more likely to be HCV-positive (0.7-2.3%) than Western participants (0.1-0.4%). Except for survey 3, second-generation non-Western migrants had a lower HCV prevalence than first-generation migrants, comparable to Western migrants and the Dutch population. Phylogenetic analysis showed that the majority of the HCV-positive, first-generation non-Western non-European migrants were infected with endemic strains which are rarely observed in Europe. CONCLUSIONS: First-generation non-Western migrants are at increased risk for HCV. Phylogenetic analysis suggests that transmission likely took place in the country of origin, causing introduction but no further transmission of endemic HCV strains in the Netherlands. HCV screening and prevention programs should target first-generation, but not second-generation, non-Western migrants.

Travel-related dengue virus infection, The Netherlands, 2006-2007.

To assess the incidence of and risk factors for clinical and subclinical dengue virus (DENV) infection, we prospectively studied 1,207 adult short-term travelers from the Netherlands to dengue-endemic areas. Participants donated blood samples for serologic testing before and after travel. Blood samples were tested for antibodies against DENV. Seroconversion occurred in 14 (1.2%) travelers at risk. The incidence rate was 14.6 per 1,000 person-months. The incidence rate was significantly higher for travel during the rainy months. Dengue-like illness occurred in 5 of the 14 travelers who seroconverted. Seroconversion was significantly related to fever, retro-orbital pain, myalgia, arthralgia, and skin rash. The risk for DENV infection for short-term travelers to dengue-endemic areas is substantial. The incidence rate for this study is comparable with that in 2 other serology-based prospective studies conducted in the 1990s.

Travel-related schistosomiasis, strongyloidiasis, filariasis, and toxocariasis: the risk of infection and the diagnostic relevance of blood eosinophilia.

BACKGROUND: This study prospectively assessed the occurrence of clinical and subclinical schistosomiasis, strongyloidiasis, filariasis, and toxocariasis, and the screening value of eosinophilia in adult short-term travelers to helminth-endemic countries. METHODS: Visitors of a pre-travel health advice centre donated blood samples for serology and blood cell count before and after travel. Samples were tested for eosinophilia, and for antibodies against schistosomiasis, strongyloidiasis, filariasis, and toxocariasis. Previous infection was defined as seropositivity in pre- and post-travel samples. Recent infection was defined as a seroconversion. Symptoms of parasitic disease were recorded in a structured diary. RESULTS: Previous infection was found in 112 of 1207 subjects: schistosomiasis in 2.7%, strongyloidiasis in 2.4%, filariasis in 3.4%, and toxocariasis in 1.8%. Recent schistosomiasis was found in 0.51% of susceptible subjects at risk, strongyloidiasis in 0.25%, filariasis in 0.09%, and toxocariasis in 0.08%. The incidence rate per 1000 person-months was 6.4, 3.2, 1.1, and 1.1, respectively. Recent infections were largely contracted in Asia. The positive predictive value of eosinophilia for diagnosis was 15% for previous infection and 0% for recent infection. None of the symptoms studied had any positive predictive value. CONCLUSION: The chance of infection with schistosomiasis, strongyloidiasis, filariasis, and toxocariasis during one short-term journey to an endemic area is low. However, previous stay leads to a cumulative risk of infection. Testing for eosinophilia appeared to be of no value in routine screening of asymptomatic travelers for the four helminthic infections. Findings need to be replicated in larger prospective studies.

Fecal-orally transmitted diseases among travelers are decreasing due to better hygienic standards at travel destination.

OBJECTIVE: To evaluate whether changes in attack rates of fecal-orally transmitted diseases among travelers are related to changes in pretravel vaccination practices or better hygienic standards at travel destination. METHODS: National surveillance data on all laboratory-confirmed cases of travel-related hepatitis A, shigellosis, and typhoid fever diagnosed in the Netherlands from 1995 to 2006 were matched with the number of Dutch travelers to developing countries to calculate region-specific annual attack rates. Trends in attack rates of non-vaccine-preventable shigellosis were compared with those of vaccine-preventable hepatitis A and typhoid fever. Trends were also compared with three markers for hygienic standards of the local population at travel destinations, drawn from the United Nations Development Programme database: the human development index, the sanitation index, and the water source index. RESULTS: Attack rates among Dutch travelers to developing regions declined for hepatitis A, shigellosis, and typhoid fever. Region-specific trends in attack rates of shigellosis resembled trends of hepatitis A and typhoid fever. Declining attack rates of the three fecal-orally transmitted diseases correlated with improvements in socioeconomic, sanitary, and water supply conditions of the local population at travel destination. CONCLUSIONS: These findings suggest that improved hygienic standards at travel destination strongly contributed to the overall decline in attack rates of fecal-orally transmitted diseases among visiting travelers.

Symptoms of infectious diseases in travelers with diabetes mellitus: a prospective study with matched controls.

BACKGROUND: Travelers with diabetes mellitus to developing countries are thought to have symptomatic infectious diseases more often and longer than travelers without diabetes. Evidence for this is needed. This study evaluates whether travelers with diabetes are at increased risk of symptomatic infectious diseases. METHODS: A prospective study was performed between October 2003 and February 2008 among adult medication-dependent travelers with diabetes, with their healthy travel companions without diabetes serving as matched controls. Thus, travelers with diabetes and controls were assumed to have comparable exposure to infection. Data on symptoms of infectious diseases were recorded by using a structured diary. RESULTS: Among 70 travelers with insulin-dependent diabetes, the incidence of travel-related diarrhea was 0.99 per person-month, and the median number of symptomatic days 1.54 per month. For their 70 controls, figures were 0.74 and 1.57, respectively (p > 0.05). Among 82 travelers with non-insulin-dependent diabetes, incidence was 0.75, and the median number of symptomatic days was 1.68. For their 82 controls, figures were 0.70 and 1.68, respectively (p > 0.05). As for other symptoms, no significant travel-related differences were found. Only 17% of travelers with diabetes suffering from diarrhea used their stand-by antibiotics. CONCLUSIONS: Medication-dependent travelers with diabetes traveling to developing countries do not have symptomatic infectious diseases more often or longer than travelers without diabetes. Routine prescription of stand-by antibiotics for travelers with diabetes to areas with good health facilities is probably not more useful than for healthy travelers.