Preventing Zoonotic Canine Leishmaniasis in Northeastern Brazil: Pet Attachment and Adoption of Community Leishmania Prevention

Visceral leishmaniasis (VL), caused by Leishmania infantum chagasi (L.i. chagasi syn. infantum) in northeastern Brazil, was responsible for 51,000 new VL cases from 1980 to 2003. Household presence of L. infantum-infected dogs is a major risk factor for human infection. Despite culling of dogs based on seropositivity, canine L. infantum seroprevalence remains near 20%, suggesting that dog culling is ineffective for preventing VL spread. We administered a cross-sectional survey to 224 households within 300 m of the homes of VL human patients diagnosed within the last year. The goal was to develop a model for voluntary preventative use based on characteristics and motivations of dog owners. We identified that owner knowledge deficiencies regarding canine transmission of L. infantum associated with increased risk of dog infection (odds ratio [OR] = 3.681, confidence interval [CI] = 1.223, 11.08). Higher owner education was associated with decreased levels of dog seropositivity (OR = 0.40, CI = 0.20, 0.81). Pet attachment (P = 0.036) and perception of risk/disease knowledge (P = 0.040) were significantly associated with willingness to voluntarily purchase canine VL prevention. These results highlight the importance of owner attachment to their pet in implementing reservoir-targeted zoonotic VL prevention.     

Human and canine visceral leishmaniasis in the Papsky District, Namangan Region, Uzbekistan: seroepidemiological and seroepizootological surveys

In 2007 - 2008, four (Chodak, Oltinkan, Gulistan, and Chorkesar) of 9 population aggregates in the Papsky District, Namangan Region, Uzbekistan, where visceral leishmaniasis (VL) cases had been registered in the last years were selected to make seroepidemiological and seroepizootological surveys within the international project funded by INTAS grant 05-100006-8043. The surveys of the populations were conducted visiting their homesteads. These additionally included children's and health care facilities where all children aged less than 14 years were examined. On examining the children, their peripheral blood (approximately 0.1 ml) was taken on filter paper for serological assays. Canine blood was sampled from the vein. Enzyme-linked immunosorbent assay (ELISA) was carried out to detect antibodies to VL pathogens. A total of 521 children were examined for two years, by applying ELISA. Five hundred and fourteen blood samples from children younger than 14 years, 162 dogs, 4 foxes, and 1 cat were tested. Testing 514 children's blood samples for VL pathogen antigen ascertained that in the 4 population aggregates there was an average of 10% VL-seropositive children, including those who were ill with VL at the moment of the examination and had been ill. The highest number of VL-seropositive samples (14.9%) was found in the settlement of Chodak. VL pathogen antibodies were detected in 26 (61.9%) of 42 dogs with the clinical signs of VL. VL-positive tests were found in 26 (21.6%) of 120 apparently healthy dogs. The samples from 4 foxes and 1 cat were negative. Immunological findings indicated that 0-3-year-old children were a group that is most susceptible to VL in the study focus of this disease. The high proportion of dogs with VL may account for the rise in infant morbidity and suggests the epizootic strain in the focus of VL in the Papsky District.     

Prevalence of Toxocara canis infection in household dogs

The prevalence of Toxocara canis infection in household dogs was estimated by examining feces from 1,743 dogs aged between 1 month and 15 years old. Fecal samples from 75 (4.3%) of the 1,743 dogs were positive for the eggs of T. canis. The dogs with positive fecal samples ranged from 1 month to 5 years old in age. The infection rate in dogs aged 1 to 6 months old was significantly (p < 0.01) higher than that in dogs aged 7 months to 2 years old or over 3 years old. Indoor dogs aged 1 to 6 months old showed a significantly (p < 0.01) lower prevalence than outdoor dogs of the same age group. With respect to the place of origin of the dogs, those originating from individual households (5.7%) showed (p < 0.05) a higher prevalence as compared to the animals purchased from pet shops/breeding kennels (3.5%). Considering the origin and the living conditions, the prevalence in indoor dogs originating from individual households was significantly (p < 0.05) higher than that in indoor dogs purchased from pet shops/breeding kennels.     

SARS-CoV-2 infection in households with and without young children: Nationwide cohort study,Denmark, 27 February 2020 to 26 February 2021

BackgroundInfections with seasonally spreading coronaviruses are common among young children during winter months in the northern hemisphere; the immunological response lasts around a year. However, it is not clear if living with young children changes the risk of SARS-CoV-2 infection among adults.AimOur aim was to investigate the association between living in a household with younger children and the risk of SARS-CoV-2 infections and hospitalisation.MethodsIn a nationwide cohort study, we followed all adults in Denmark aged 18 to 60 years from 27 February 2020 to 26 February 2021. Hazard ratios of SARS-CoV-2 infection by number of 10 months to 5 year-old children in the household were estimated using Cox regression adjusted for adult age, sex and other potential confounders. In a sensitivity analysis, we investigated the effect of the children''s age.ResultsAmong 450,007 adults living in households with young children, 19,555 were tested positive for SARS-CoV-2, while among 2,628,500 adults without young children in their household, 110,069 were tested positive for SARS-CoV-2 (adjusted hazard ratio (aHR) = 1.10; 95% confidence interval (CI): 1.08–1.12). Among adults with young children, 620 were hospitalised with SARS-CoV-2, while 4,002 adults without children were hospitalised with SARS-CoV-2 (aHR = 0.97; 95% CI: 0.88–1.08). Sensitivity analyses found that an increasing number of younger children substantially increased the risk of SARS-CoV-2 infection but not hospitalisation.ConclusionLiving in a household with young children was associated with a small increased risk of SARS-CoV-2 infection.     

Sero-epidemiology of Toxocara canis infection among aboriginal schoolchildren in the mountainous areas of north-eastern Taiwan

A sero-epidemiological study of Toxocara canis infection was conducted among Atayal schoolchildren (aged 7-12 years) residing in the mountainous areas of north-eastern Taiwan. The 73 children investigated were each checked for anti-Toxocara IgG, in ELISA based on the larval excretory-secretory antigens of T. canis larvae. A short, self-administered questionnaire was then used to collect relevant information from each subject, including data on the keeping of dogs, playing in soil, eating raw vegetables, and whether the subjects normally washed their hands before eating. Once the seropositive children had been identified, odds ratios (OR), with their corresponding 95% confidence intervals (CI) and P-values, were calculated for each potential risk factor. When diluted 1:64, sera from 42 (57.5%) of the children gave a positive result in the ELISA, indicating that these 42 children were seropositive for T. canis infection. Seropositivity did not appear to be associated with the age or gender of the subject, the eating of raw vegetables, or the regular failure to wash hands prior to a meal. Compared with the other subjects, however, those who admitted living in a household where dogs were kept (OR = 3.79; CI = 1.23-11.69; P = 0.02) or playing in soil (OR = 3.00; CI = 1.10-8.16; P = 0.03) appeared at increased risk of seropositivity.     

Transmission of Helicobacter pylori infection in families of preschool-aged children from Minas Gerais, Brazil

We evaluated the role of the family in the transmission of Helicobacter pylori infection in preschool-aged children from a rural district in the State of Minas Gerais, Brazil. Sixty-six families (66 index children, 63 mothers, 60 fathers and 134 siblings), defined as at least one parent living in the same household with at least one offspring up to 8 years old, were studied. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression controlling for age, gender, number of children in household and H. pylori status of the father, mother and siblings. The prevalence of the infection was 69.7% (469 of 673) and it increased with age (P < 0.001). Positive mothers were a strong and independent risk factor for infection (OR 22.70; 95% CI 2.31-223.21). Positive siblings were also positively associated with infection (OR 1.81; 95% CI 1.01-3.30).     

Risk factors for in-hospital mortality of visceral leishmaniasis patients in eastern Uganda

Objective  To identify risk factors for in-hospital mortality in patients treated for visceral leishmaniasis (VL) in Uganda.
Methods  Retrospective analysis of VL patients' clinical data collected for project monitoring by Médecins Sans Frontières in Amudat, eastern Uganda.
Results  Between 2000 and 2005, of 3483 clinically suspect patients, 53% were confirmed with primary VL. Sixty-two per cent were children <16 years of age with a male/female ratio of 2.2. The overall case-fatality rate during pentavalent antimonial ( n  = 1641) or conventional amphotericin B treatment ( n  = 217) was 3.7%. There was no difference in the case-fatality rate between treatment groups ( P  > 0.20). The main risk factors for in-hospital death identified by a multivariate analysis were age <6 years and >15 years, concomitant tuberculosis or hepatopathy, and drug-related adverse events. The case-fatality rate among patients >45 years of age was strikingly high (29.0%).
Conclusion  Subgroups of VL patients at higher risk of death during treatment with drugs currently available in Uganda were identified. Less toxic drugs should be evaluated and used in these patients.     

Longitudinal cohort study of the epidemiology of malaria infections in an area of intense malaria transmission II. Descriptive epidemiology of malaria infection and disease among children.

A large-scale longitudinal cohort project was initiated in western Kenya in June 1992. Between June 1992 and July 1994, 1,848 children less than 15 years of age were monitored prospectively for a mean of 236 days. During this period, 12,035 blood smears were examined for malaria and only 34% were found to be negative. Parasite prevalence (all species) decreased with age (from a high of 83% among children 1-4 years old to 60% among children 10-14 years old). Even more dramatic decreases were noted in the prevalence of high density falciparum infection (from 37% among children 12-23 months old to < 1% among 10-14-year-old children) and in clinical malaria (20% to 0.3% in the same age groups). Children < 1 year of age accounted for 55% of all cases of anemia detected. Anemia was consistently associated with high density infection in children < 10 years of age (20% to 210% increased risk relative to aparasitemic children). These results demonstrate the relationship between high-density malaria infection and two clinical manifestations of malarial illness.     

四川省黑热病流行病学和防治（摘要）

通过近２０年的调查研究，弄清了四川省流行因素及特点。犬是该病主要传染源，ＶＬ的发生和流行与犬的数量及其感染率有着密切关系。犬的感染率超过１５％可出现ＶＬ流行，低于１５％ＶＬ发病率低。１０岁以下儿童发病占患者总数的７２．２％，只要不养狗就可以控制新生儿童感染，ＶＬ病人的分布主要在沿江、河的滩地和山坡上的居民聚居地。消灭病犬、治疗病人和在疫点用杀虫剂滞留喷洒能有效控制ＶＬ流行。１９９４年的发病 为２     

Prevalence of Helicobacter pylori infection in children from an urban community in north-east Brazil and risk factors for infection

OBJECTIVES: To investigate the prevalence of Helicobacter pylori infection in a randomly selected population of children from a low income community in Brazil and the risk factors for infection. DESIGN: A cross-sectional, randomised study of prevalence and risk factors. SUBJECTS: Children living in an urban community in north-east Brazil. METHODS: H. pylori infection was determined using the C-urea breath test. Risk factors were assessed using a structured interview schedule. RESULTS: The overall prevalence of H. pylori was 56% (197/353). The infection was most common for those aged 12-14 years. In this group 75.4% (49/65) (95% CI, 63.1-85) of all children were positive for H. pylori, while in children less than 2 years of age 35.1% (13/37) (95% CI, 20.2-52.5) were positive. The prevalence of H. pylori increased significantly with age (P < 0.0001). In the bivariate analysis, a significant difference was found in the prevalence of H. pylori infection and age, number of persons per room, the number of children per household, cup sharing, and type of drinking water (P < 0.05). However, after logistic regression modelling only age (odds ratio (OR) = 1.3; 95% confidence interval (CI), 1.07-1.65), and number of persons per room (OR = 2.58; 95% CI, 1.4-4.6) were risk factors for H. pylori infection. CONCLUSIONS: H. pylori is highly prevalent among children in a north-eastern Brazilian community characterised by poor living conditions, and this infection is largely acquired during early childhood. The infection increased with age, and domestic overcrowding. Further longitudinal studies must examine in depth the possible modes of transmission of the organism in young children.     

Hepatitis A seroprevalence in children and adolescents aged 1-18 years among a low socioeconomic population in Izmir, Turkey

The age-specific prevalence of hepatitis A virus (HAV) infection and risk factors were evaluated in a low socioeconomic population in Izmir. Children and adolescents 1-18 years of age admitted to the outpatient clinics for follow-up visits, or healthy children between April-December 2009 were investigated for anti-HAV antibodies by a cross-sectional study. A questionnaire on sociodemographic and hygiene information was obtained from the parents. All unvaccinated children against HAV were grouped according to their age. Seven hundred and twenty-nine children were enrolled in the study. Total HAV IgG seropositivity was 29.5% while age related values were as follows: 1-2 years, 21.4%; 2.1-5 years, 15.1%; 5.1-8 years, 20.1%; 8.1-11 years, 32.6%; 11.1-14 years, 44.3% and 14.1-18 years, 52.4%. The presence of anti-HAV IgG was associated significantly with low family income and lack of education of parents and living in a crowded family. HAV infection was endemic in a population of children living in Izmir. Anti-HAV vaccination should be considered for preschool children because teenagers are at risk of infection in this region.     

Six years' experience with the discontinuation of BCG vaccination: 3. Transmission of tubercle bacilli in an unvaccinated population

Setting: Mass BCG vaccination of newborns has been discontinued since 1986 in one third of the Czech Republic (30 000 newborns annually) except for babies with a high risk of tuberculosis.Objective: The transmission and risk of tuberculosis infection were evaluated in non-BCG-vaccinated children representing a population living in satisfactory socio-economic conditions.Design: In 1986–1992, of 184 648 children tuberculin tested at 2-year intervals, 283 were infected.Results: The risk of infection was low (0.04%). Infections very rarely occurred in children below the age of 1 year and the highest rate was in children 2–3 years old. The sources of infection were found in the families of only one half of the youngest children and in 10% of the older ones. In the remaining children occasional contacts with sources outside the family must be taken into account, but the mode of contact and transmission of infection were not identified. The only factor contributing to tuberculosis transmission was the high population density.Conclusion: The risk of infection was low and identified sources of tuberculosis were rare in a stable population of children without evident risk factors. Children were infected by occasional contact with tuberculous cases outside of their families. The unfavourable factors associated with living in overcrowded industrialised settlements contributed to the risk of infection of non-BCG-vaccinated children.     

The epidemiology of viral hepatitis in children in South Texas: increased prevalence of hepatitis A along the Texas-Mexico border.

An initial retrospective study of 194 children demonstrated a high prevalence of hepatitis A but not hepatitis B or C infection among children living along the Texas-Mexico border. A larger prospective study of hepatitis A was conducted with 285 children (aged 6 months to 13 years) living in 3 sociodemographically dissimilar areas of South Texas. Children living in colonías along the border had a significantly higher prevalence of hepatitis A virus infection (37%) than children living in urban border communities (17%) or in a large metropolitan area (San Antonio [6%]). Independent risk factors for hepatitis A infection included increased age, colonía residence, and history of residence in a developing country. Use of bottled water (vs. municipal or spring/well water) and years of maternal secondary education were protective. Improved sanitation or routine hepatitis A vaccination in early childhood may reduce the prevalence of hepatitis A in these areas.     

Epidemiological aspects and risk factors of toxocariasis in a pediatric population in Sri Lanka

This cross-sectional study, carried out over a period of 11 months, investigated the relationship between Toxocara seropositivity, socio-demographic and environmental variables in a pediatric population. Risk factors for Toxocara infection were assessed by direct interview of parent or guardian using a structured pre-tested questionnaire. Eosinophilia and presence of helminth eggs or protozoan cysts in a fecal smear were recorded. Diagnosis of Toxocara seropositivity in children was based on IgG Toxocara Microwell Serum Elisa Kits. The ELISA test was regarded as positive if the optical density was 0.3 units or above. Unadjusted and adjusted odds ratios were calculated to determine risk factors for disease. The proportion of children who were positive for Toxocara antibodies in the study population was 20%. Children being exposed to a puppy of less than 3 months at home, visiting a playground frequently, living in a poorly constructed house and dogs having access to playgrounds were significant risk factors on univariate analysis. Of these four variables, only the first three variables (OR 19, OR 4 and OR 3, respectively) remained significant risk factors on the multivariate model. Presence of eosinophilia in seropositive children was significantly higher than the seronegative group (77% vs 40%; p < 0.001). This study indicates that dogs contribute significantly to children being seropositive for toxocariasis in Sri Lanka. Implementation of public health programs specifically focused on anti-parasitic treatment of dogs is recommended.     

Toxocara seroprevalence in children from a subtropical city in Argentina

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.     

Virgin soil: the spread of visceral leishmaniasis into Uttar Pradesh, India

We conducted a cross-sectional study to determine the incidence of visceral leishmaniasis (VL) and risk factors in two villages in Uttar Pradesh, India reported to have had a recent outbreak. In 245 households with 2,203 people, we detected 3 current VL cases, 32 past cases, and 8 VL deaths since 2001 (annual incidence = 6 per 1,000). Risk factors included living in the same household as a VL case (odds ratio [OR] = 76, P < 0.0005 in one village and OR = 22, P < 0.0005 in the other village), sleeping downstairs and outside in the summer (OR = 4.7, P = 0.004), and an age > or = 15 years old (OR = 2.9, P = 0.024). Increasing cattle density was a risk factor in one village but not the other. We were not able to determine the route by which VL entered the villages. Our data demonstrate a new spread of VL in previously unaffected areas. We recommend carefully supervised spraying with DDT, surveillance to pinpoint other affected villages, and efforts to increase availability of diagnostic and treatment facilities.     

Relationship between viral load and self-report measures of medication adherence among youth with perinatal HIV infection

Poor adherence to antiretroviral therapy (ART) contributes to disease progression and emergence of drug-resistant HIV in youth with perinatally acquired HIV infection (PHIV +), necessitating reliable measures of adherence. Although electronic monitoring devices have often been considered the gold-standard assessment in HIV research, they are costly, can overestimate nonadherence and are not practical for routine care. Thus, the development of valid, easily administered self-report adherence measures is crucial for adherence monitoring. PHIV+youth aged 7–16 (n = 289) and their caregivers, enrolled in a multisite cohort study, were interviewed to assess several reported indicators of adherence. HIV-1 RNA viral load (VL) was dichotomized into >/≤400 copies/mL. Lower adherence was significantly associated with VL >400 copies/mL across most indicators, including ≥1 missed dose in past seven days [youth report: OR = 2.78 (95% CI, 1.46–5.27)]. Caregiver and combined youth/caregiver reports yielded similar results. Within-rater agreement between various adherence indicators was high for both youth and caregivers. Inter-rater agreement on adherence was moderate across most indicators. Age ≥13 years and living with biological mother or relative were associated with VL >400 copies/mL. Findings support the validity of caregiver and youth adherence reports and identify youth at risk of poor adherence.     

Respiratory syncytial virus evaluation among asymptomatic and symptomatic subjects in a university hospital in Sao Paulo,Brazil, in the period of 2009‐2013

Background

The respiratory syncytial virus (RSV) is recognized as an important cause of respiratory tract infections. Immunocompromised patients, healthcare workers (HCWs) and children contacts are at increased risk of acquiring the infection. However, the impact of asymptomatic infection in transmission has not been well studied. Objectives: this study evaluated the frequency and viral load (VL) of RSV in nasal swab samples of individuals with different risk factors for acquiring infection in a university hospital in Sao Paulo, Brazil.

Methods

We included 196 symptomatic children and their 192 asymptomatic caregivers, 70 symptomatic and 95 asymptomatic HCWs, 43 samples from symptomatic HIV‐positive outpatients, and 100 samples of asymptomatic HIV patients in the period of 2009‐2013.

Results

RSV infection was detected in 10.1% (70/696) of samples, 4.4% (17/387) of asymptomatic patients, and 17.1% (53/309) from symptomatic patients. (P < .0001). The VL of symptomatic patients (4.7 log copies/mL) was significantly higher compared to asymptomatic patients (2.3 log copies/mL). RSV detection among asymptomatic caregivers (6.8%; 13/192) was significantly higher compared to other asymptomatic adults, HIV and HCWs (2.0%; 4/195; P = .0252). A close contact with an infected child at home was an important risk to RSV acquisition [OR 22.6 (95% CI 4.8‐106.7)]. Children who possibly transmitted the virus to their asymptomatic contacts had significantly higher viral load than children who probably did not transmit (P < .0001).

Conclusions

According to our results, it is important to know if people circulating inside the hospital have close contact with acute respiratory infected children.     

The northward spread of leishmaniasis in Italy: evidence from retrospective and ongoing studies on the canine reservoir and phlebotomine vectors

Visceral leishmaniasis (VL) incidence has been increased in Italy in humans and dogs since the 1990s, with new foci being detected within traditional boundaries of endemic transmission but also in northern regions previously regarded as non-endemic. To monitor the putative VL spreading, surveillance was implemented in northern continental Italy comprising: analysis of human cases recorded from 1990 through 2005; retrospective literature analysis of canine leishmaniasis (CanL) and phlebotomine sandfly records through 2002; prospective investigations in dogs from 2003 through 2005 and surveys on sandflies in 2003 and 2004. Two-hundred-thirty human cases (11% of Italian cases) were recorded. Their stratification by age and HIV status disclosed a sharp decrease of HIV/VL co-infections paralleled by concomitant increase of paediatric and HIV-negative adult patients during the study period. Four patients had no travel history. Seven leishmaniasis foci were retrospectively identified since 1990, whereas prospective investigations in dogs disclosed 47 autochthonous clinical cases and 106 autochthonous seropositives among 5442 dogs (2.1%) from 16 foci of six regions. Parasites were typed as Leishmania infantum MON-1. Four vector species were identified among 1696 Phlebotomus (Larroussius) collected specimens. Comparisons with historical data showed that P. perniciosus and P. neglectus have increased in density and expanded their geographic range in the study area. Northern continental Italy is now focally endemic for VL and a moderate risk for human disease does exist, although the intensity of transmission seems to be lower than in traditional settings of Mediterranean VL.