Tropical Medicine & International Health最新文献

Background: Helminthiasis co-exists with malaria in endemic areas; this co-existence can influence anaemia, iron, and folate levels in patients. This study was aimed at assessing the effect of malaria, helminthiasis, and co-infection on anaemia, iron, and folate deficiencies in children.

Methods: The study participants comprised of 1003 children, from whom venous blood and stool samples were obtained. Structured questionnaires were used to assess sociodemographic and household data. Venous blood from children (aged 1-15 years) was analysed for malaria parasitaemia and full blood count. Kato Katz and formol ether concentration techniques were used to analyse stool samples for intestinal parasites. Indirect ELISA was performed on the serum samples to determine iron and folate levels.

Results: Overall, malaria and intestinal helminths prevalence were 54.4% (546/1003) and 15.7% (172/1003), respectively. Ascaris lumbricoides, Taenia spp., hookworm, Trichuris trichiura and Strongyloides stercoralis were identified as mono-infection or in co-infection with malaria (11.4%) or intestinal protozoa (1.5%). These prevalence rates were significantly higher in less urbanised northern study sites (p < 0.0001) and among younger children (p < 0.0001). Malaria (p < 0.0320), intestinal helminths (p < 0.0001) and malaria-helminthiasis co-infection (p < 0.0320) were independent predictors of anaemia. Malaria and intestinal helminths co-infection significantly worsens anaemia (p < 0.001), folate deficiency (p < 0.001) and iron deficiency (p < 0.001) compared to those with malaria only.

Conclusion: Malaria and helminthiasis predominantly affect children and are influenced by age, gender, locality, and urbanisation. Co-infection exacerbates the adverse outcomes associated with malaria.

Objectives: Rickettsioses are frequent causes of treatable febrile illness in Southeast Asia, including Myanmar. Accurate estimates of the incidence of rickettsioses are needed to inform investments in disease prevention and control. We sought to estimate the incidence of rickettsioses among adults and adolescents by combining sentinel hospital surveillance with a healthcare utilisation survey in Yangon, Myanmar.

Methods: We conducted a household-based healthcare utilisation survey in the Yangon Region from 12 March through 5 April 2018. Multipliers derived from this survey were then applied to scrub typhus, murine typhus, and spotted fever group rickettsioses infections identified from a study of adolescent and adult community-onset febrile illness done from 5 October 2015 through 4 October 2016 at Yangon General Hospital to estimate disease incidence. Acute serum was collected at enrolment and convalescent serum 14-30 days after enrolment. Confirmed acute scrub typhus, murine typhus, and spotted fever group infections were diagnosed by a ≥ 4-fold rise between acute and convalescent immunofluorescent antibody test titre to Orientia tsutsugamushi pooled Karp, Kato, and Gilliam antigens; Rickettsia typhi Wilmington strain; and Rickettsia honei and Rickettsia conorii antigens, respectively.

Results: After applying multipliers, we estimated the overall annual incidence of acute scrub typhus among adolescents and adults in the Yangon Region at 211 cases per 100,000 persons, and the overall estimate of acute murine typhus among adults and adolescents was 44 cases per 100,000 persons per year for 2015-2016. There were no confirmed spotted fever group infections.

Conclusions: We provide the first estimates of scrub typhus and murine typhus community incidence in Myanmar. Similar research in children and from other parts of Myanmar, as well as studies of illness duration, complications, and deaths, is needed to estimate the disease burden.

Objectives: Our study aims to (i) evaluate the yield and costs of a fully automated interactive voice response survey as a screening tool for identifying rural respondents for participation in a mortality mobile phone survey, and (ii) compare mortality survey call outcomes among interactive voice response pre-screened and unscreened numbers.

Methods: In order to identify respondents living in rural areas, a short interactive voice response survey was conducted among 24,924 unique mobile phone numbers to determine place of residence (Rural vs. Other). We calculated the proportion of rural numbers derived from the interactive voice response survey among all numbers dialled. Mobile phone numbers screened with interactive voice response were then combined with those generated via random digit dialling and used in a national mortality mobile phone survey in Malawi. Final dispositions for each mobile number dialled were compared for both groups by testing the difference in proportions.

Results: Approximately half of all phone numbers dialled in the interactive voice response survey were answered, and among them, 33.9% indicated that they lived in a rural area. The cost per completed interactive voice response was US$8.75 and just under half of the numbers screened by interactive voice response later resulted in a completed mortality mobile phone survey, at a cost of US$17.4 per completed mortality survey. In comparison, less than a quarter of the numbers that were not screened through interactive voice response resulted in a completed mortality survey (45.3% vs. 22.3%, p <0.001). On average, 12 call attempts were required to complete a mortality survey interview in the unscreened group, compared to 6.3 call attempts among the interactive voice response pre-screened numbers.

Conclusions: Interactive voice response surveys can be used to increase the representation of rural respondents in mobile phone surveys at an acceptable cost. Modifications to the interactive voice response survey process (e.g., survey timing and number of call attempts) should be explored further to increase engagement.

Objectives: Molecular xenomonitoring is a surveillance method for vector-borne diseases where vectors are tested for molecular pathogen markers. Testing is typically on pools (groups) of vectors. Molecular xenomonitoring is a sensitive and efficient complement to human-based surveillance. However, existing statistical guidance for the appropriate design and analysis of molecular xenomonitoring surveys has key gaps. We reviewed the literature to understand the common objectives, survey designs, and analysis methods for molecular xenomonitoring surveys for two vector-borne neglected tropical diseases: lymphatic filariasis and onchocerciasis.

Methods: We searched peer-reviewed literature for studies published between 1999 and 2022 that presented the results of surveys that collected vectors in field surveys and used a molecular test for the presence of the causative pathogens for lymphatic filariasis and onchocerciasis.

Results: Out of 1225 works identified in the database search, a total of 76 studies (lymphatic filariasis: 45; onchocerciasis: 31) across 30 countries were included in the review. The five most common objectives were determination of elimination status after mass drug administration, comparison of vector and human infection indicators, evaluation of an intervention, comparison of vector collection methods and comparison of laboratory techniques. Nearly all studies used a cluster or hierarchical sampling framework to collect vectors (72/76), but very few studies accounted for this in their designs (2/76) or analysis (1/76). While few studies justified the number of vectors included in each pool (5/76), nearly all studies accounted for pooled testing when calculating pathogen prevalence from results (69/76). Few studies justified the number or selection of collection sites or total sample size (16/76).

Conclusions: Published molecular xenomonitoring surveys for lymphatic filariasis and onchocerciasis had varied objectives, study designs and analysis methods, but proper consideration of survey design was frequently missing from the analysis. There is a need for statistical tools and guidance to enable appropriate design and analysis of molecular xenomonitoring surveys while accounting for disease, objective and context-specific considerations.

Zoonotic diseases whose transmission processes are sensitive to environmental characteristics represent an important public health burden in Australia, particularly in Queensland. This study aimed to analyse the epidemiology of hospitalisations from the four main environmental zoonotic diseases-leptospirosis, melioidosis, Q fever, and Ross River virus-from 2012 to 2019 in Queensland. Our analyses reveal an increasing trend of hospitalisation incidence for melioidosis, stable incidence for Q fever and Ross River virus infection, and a declining trend for leptospirosis. We identified sex and age disparities in hospitalisations, with males being more likely to be hospitalised for leptospirosis, melioidosis, and Q fever compared to females. We also uncovered discrepancies between hospitalisation and notification data, which could be attributed to diagnostic and reporting criteria. The findings of this study show that the epidemiological patterns of hospitalisation are different to the notification for the same diseases and underscore the importance of accurate recording and reporting of zoonoses-related hospitalisations to inform environmental public health interventions.

Objectives: Crimean-Congo haemorrhagic fever is a lethal tick-borne disease characterised by initially nonspecific symptoms. While thrombocytopenia and leucopenia are established diagnostic markers, there is a need for earlier indicators. This study evaluates lymphopenia as a marker for Crimean-Congo haemorrhagic fever.

Methods: This retrospective study analysed patients admitted with arthropod bites from 2018 to 2021. Patients were classified based on initial leucocyte and platelet counts into Group 1 (normal values) and Group 2 (low values). Within Group 1, patients were classified as Group 1B if they developed thrombocytopenia and leucopenia during follow-up, whereas those with stable counts were designated as Group 1A. Variance and ROC curve analysis were used to evaluate blood counts.

Results: Of 914 evaluated patients, 870 with normal CBCs were categorised into Group 1, and 44 with low counts into Group 2. Within Group 1, 16 patients subsequently developed thrombocytopenia and leucopenia (Group 1B), while the rest remained stable (Group 1A). All patients in Groups 1B and 2 were later confirmed to have Crimean-Congo haemorrhagic fever via RT-PCR. Initial lymphocyte counts varied significantly, with 2.7 × 10⁹/L in Group 1A, 0.52 × 10⁹/L in Group 1B, and 0.42 × 10⁹/L in Group 2, with notable reductions observed in Group 1B and Group 2 (p < 0.001). ROC analysis showed lymphocyte counts below 1.19 × 10⁹/L were the most sensitive and specific for Crimean-Congo haemorrhagic fever (area under curve is 0.976 [95% CI: 0.957-0.995]), exceeding traditional markers.

Conclusions: Lymphocyte depletion precedes changes in leucocyte and platelet counts, affirming its potential as an early diagnostic marker for Crimean-Congo haemorrhagic fever. Early detection through lymphocyte monitoring could improve patient management and reduce transmission in endemic areas.

Objectives: Industrial zones are large, unsupervised areas with a high risk of Aedes vector infestation because of the presence of diverse artificial breeding habitats. Unlike community-based Aedes surveys, research on vector breeding in industrial settings is limited. Therefore, this research aimed to explore Aedes vector infestation levels in industrial regions, their breeding places and the presence of dengue virus transmission.

Methods: An Aedes immature survey was conducted in 70 industrial units of an urban industrial estate of Puducherry, following standard protocols by the National Centre for Vector Borne Disease Control. The collected immatures were reared for adult emergence and species identification. Larval indices and breeding habitat contribution for Aedes aegypti and Aedes albopictus were carried out. Furthermore, adult traps were set up to detect the presence of Dengue viral RNA in adult mosquitoes. Chi-square statistics were performed to find the association of breeding positivity with industry types and container types.

Results: Aedes breeding was noted in 48 units (68.6%). All industrial types had remarkably high Aedes indices. In industrial areas, Ae aegypti was the most common dengue vector species, followed by Ae. albopictus. Out of the nine major container types, discarded types had a 90% positivity rate. Significant associations were also noted between container positivity and industry type (Χ² 15.7, p < 0.001), mosquito species and industry type (Χ² 16, p = 0.0143) and container type on mosquito breeding (Χ² 48.9, p < 0.001). Molecular analysis showed no detectable levels of dengue virus in the mosquito samples.

Conclusion: Surveillance on Aedes density is important in determining factors related to dengue transmission, in order to prioritise areas and seasons for vector control. Aedes mosquito populations in industrial settings pose a serious threat to public health. Appropriate surveillance and control strategies need to be framed for such large non-residential areas at a policy level. Combining environmental management techniques, innovative vector control methods and community engagement may help reduce the health concerns associated with Aedes in these complex industrial settings.

Background: Despite the pivotal role of healthcare workers in vaccination programs, there is limited understanding of the factors influencing their vaccine recommendations, particularly in low-resource and rural settings. This study examines the determinants of vaccine recommendation practices among healthcare workers in Senegal.

Methods: A cross-sectional survey was conducted in 2024 among 302 healthcare workers in Senegal. A vaccine recommendation score was constructed to assess how frequently healthcare workers recommended vaccines. A typology of psychosocial determinants of healthcare workers' vaccination behaviour was developed using the short version of the Health Professionals Vaccine Confidence and Behaviours questionnaire. Multivariable log-binomial regression was used to identify factors associated with systematic vaccine recommendations.

Results: Vaccine recommendation practices among healthcare workers were high, with 60.6% achieving the highest score. The Professionals Vaccine Confidence and Behaviours typology classified healthcare workers into three clusters: 'Highly confident' (57.3%), 'Moderately hesitant' (14.2%), and 'Specific hesitant' (28.5%). Healthcare workers with more than 3 years of experience and those in urban areas were significantly more likely to systematically recommend vaccines. Conversely, healthcare workers displaying higher complacency, lower openness to patients, reduced commitment to vaccination, and limited self-efficacy were less consistent in their recommendations.

Conclusion: While healthcare workers in Senegal demonstrate high vaccine confidence and vaccine recommendation practices, disparities between urban and rural settings highlight the need for targeted interventions. Efforts should focus on enhancing training, resources, and support for healthcare workers in rural areas to address barriers and strengthen vaccine promotion. Future research should explore contextual factors shaping healthcare workers' vaccination attitudes and practices to inform tailored strategies for equitable vaccination uptake.

Objectives: This study investigated the association of air pollution and spirometry indicators, and fractional exhaled nitric oxide in stable asthmatic and non-asthmatic children.

Methods: A cross-sectional study with a nested case-control analysis was conducted in Ho Chi Minh City (1 December 2022 to 31 January 2023), involving 36 asthmatic children conveniently recruited from a pulmonary clinic and 170 non-asthmatic students randomly selected from two districts, all aged 12-14. After propensity score matching on key covariates, the final sample included 36 asthmatic and 81 non-asthmatic participants. Data on spirometry, fractional exhaled nitric oxide, and air pollution exposures, including fine particulate matter levels, were collected via surveys and direct measurements.

Results: Multivariate regression found significant associations between air pollution exposures and spirometry indicators; specific exposures linked to larger lung-function declines and fractional exhaled nitric oxide increases in asthmatic versus non-asthmatic children. In asthmatics, mosquito-coil use (≥1/week) was associated with a 5.46% FEV₁/FVC drop (p = 0.043; p_(diff) = 0.020); a 16.69% FEF_25-75 decline (p = 0.029; p_(diff) = 0.010); and an 18.30 ppb fractional exhaled nitric oxide rise (p = 0.038; p_(diff) = 0.016)-none significant in non-asthmatics. In non-asthmatic children, each 1 μg/m³ PM_2.5 increase was tied to a 0.113% FEV₁/FVC fall (p = 0.043; p_(diff) = 0.037) and window opening to a 5.18% FEF_25-75 drop (p = 0.045; p_(diff) = 0.041), effects absent in asthmatics.

Conclusions: Air pollution was associated with reduced lung function and elevated airway inflammation in children, with certain exposures having stronger effects in those with asthma. These findings underscore the urgency to reduce both indoor and outdoor air pollution to protect children's respiratory health.

Introduction: Tuberculosis (TB) and diabetes mellitus comorbidity can lead to poor TB treatment outcomes, particularly with uncontrolled blood glucose levels. Understanding the impact of glycemic control on TB treatment outcomes is essential.

Objective: To synthesise evidence on the association between glycemic control and TB treatment outcomes in patients with TB and diabetes mellitus.

Methodology: A systematic review was conducted using Medline, Embase, Scopus, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Google Scholar for all types of studies published between 1975 and May 2024, including adult TB patients of >18 years of age, with or without diabetes mellitus for whom blood glucose testing along with TB treatment outcome comparison with glucose levels (low/high) was reported were considered for inclusion. A random-effects model was used for meta-analysis, heterogeneity was assessed using I-squared statistics, subgroup and sensitivity analysis was performed followed by publication bias assessment.

Results: Of 576 identified studies, 12 met the inclusion criteria, analysing 2320 cases (1572 with uncontrolled high blood glucose [≥7% HbA1c] and 748 with controlled low blood glucose [<7% HbA1c]). Low certainty evidence shows that patients with uncontrolled high glucose had a 1.91 times higher risk of TB treatment failure (risk ratios [RR] = 1.91, 95% confidence interval [CI] 1.81-3.07, p = 0.008), and a 2.97 times higher risk of sputum positivity at 3 months (RR = 2.97, 95% CI 1.10-8.07, p = 0.03). Subgroup and sensitivity analyses showed significant improvement in pooled effects, lowering of heterogeneity and narrower CIs. For overall pooled effect, substantial heterogeneity was observed; therefore, the interpretation and generalisation of results should be done with caution.

Conclusion: A low certainty evidence shows that uncontrolled high blood glycemic level significantly impacts TB treatment outcomes, increasing treatment failure and sputum positivity among TB patients with diabetes mellitus.