Objective: To assess prevalence and factors associated with soil-transmitted helminth (STH) infections among rural school children.

Methods: This school-based survey applied a cross-sectional design which included children aged 6-14 years enrolled in 12 elementary schools in Banjarwangi, Garut, West Java Province. Stool and blood samples were collected from 388 randomly selected students to examine the STH infections and anemia status, respectively. Anthropometric assessment was performed to profile nutritional status. A structured questionnaire was employed to collect socio-demographic and school performance data. Multivariable logistic regression models were built to assess the factors associated with STH infections in school children.

Results: Among 386 schoolchildren, 9.8% children were positive for one or more STH infections, predominantly Trichuris trichiura (9.0%), with males (n=23), significantly more infected than females (n=13) (5.9% vs. 3.4%, P=0.04). The most infected age group was 6-10 years (n=25, 6.5%). The prevalence of STH infection was significantly higher among students that practicing open defecation (n=22, 5.7%) (P=0.03). The odds risk of STH infections was associated with practicing open defecation (aOR 2.54, 95% CI 1.17-5.53, P=0.02).

Conclusions: The findings from this study demonstrate the persistent STH transmission among children underscoring the need for sustained post-MDA intervention strategies in resource-limited settings.

Objective: To investigate the genetic diversity and population structure of the helminth intermediate host, Anentome (A.) helena, populations from northern Thailand and reveal the effect of parasitic infection on snail host populations.

Methods: A. helena was collected throughout river drainages from northern Thailand and investigated for larval trematode infection. Seventy-three A. helena specimens were used to examine and re-construct the molecular phylogenetics (neighbour-joining, maximum likelihood, and Bayesian inference methods), genetic diversity, and population structure based on the concatenated datasets of COI and 16S rRNA (1 178 bp).

Results: The infection of zoogonid cercariae, heterophyid metacercariae, and echinostome metacercariae in the snail was found from 2 localities, including Mae Sa and Mae Pu Kha populations, with a total prevalence of 6.7% and 16.3%, respectively. The phylogenetic tree and haplotype network revealed three main clades and three haplogroups for each region (COI and 16S rRNA). High levels of genetic diversity in terms of haplotype diversity were found in parasitic infected populations.

Conclusions: This is the first time that Echinostoma mekongi has been discovered from A. helena in northern Thailand. The results also showed that parasitic infection can affect the population genetic structure of the snail intermediate host, A. helena. Moreover, habitat and historical demographic changes could be other important factors that can affect the degree of population genetic structure in A. helena. Understanding the population structure of intermediate host species can inform parasite transmission dynamics and is useful for the creation of effective public health management strategies.

Objective: To investigate whether urinary dipstick proteinuria or urine protein creatinine ratio (UPCR) could predict leakage in children with dengue virus infection.

Methods: This was a prospective cross-sectional study. A total of 141 hospitalized patients with confirmed dengue virus infection were enrolled from three hospitals in Thailand. Once daily, complete blood count, serum albumin, and random morning urine dipstick protein were collected from the day of admission to the day after defervescence. Morning UPCR was only measured in patients from one hospital due to logistic reasons.

Results: There were 81 and 60 patients in the dengue fever (DF) and DHF groups, respectively. The proportion of patients with proteinuria detected using urine dipstick in the DHF group was higher than that in the DF group from Day-1 (one day before defervescence) to Day +1 (one day after defervescence). Urine dipstick for proteinuria of ≥1+ had sensitivity and specificity of 12.8% and 94.4% on Day-1, and 18.9% and 98.6% on Day 0 (the day of defervescence) to differentiate DHF from DF. For UPCR, cut-off values of approximately 0.2 g/g from Day-2 to Day+1 yielded a sensitivity of 71.6%-94.4% and a specificity of 55.6%-100% in differentiating between DF and DHF.

Conclusions: Dipstick proteinuria of ≥1+ on Day-1 to Day+1 after defervescence had poor sensitivity but good specificity in differentiating DHF from DF. UPCR performed better but was less convenient and more expensive than urine dipsticks.

Objective: To evaluate the effects of primary anti-dengue virus envelop protein domain 3 (DENV-ED3) antibodies on secondary heterotypic anti-DENV ED3 antibody responses and the status of anti-DENV antibody responses against multivalent DENV ED3s in mice.

Methods: Four different DENV-ED3s were purified and their biophysical characteristics were confirmed. Swiss albino mice aged 3-4 weeks were immunized with four different DENV-ED3s and the anti-ED3 IgG responses were determined by ELISA.

Results: Firstly, the primary 1ED3-2ED3-3ED3 cross-reactive anti-DENV1 ED3 response boosted the secondary anti-2ED3 and anti-3ED3 antibody responses. In contrast, primary anti-2ED3 and anti-3ED3 antibodies neither had cross-recognition of 1ED3, nor had any effect on secondary anti-1ED3 response. Besides, the strict serospecificity of the anti-4ED3 sera did not affect other secondary anti-DENV ED3 responses. Secondly, 1ED3, 2ED3, and 3ED3 were co-dominantly immunogenic in trivalent ED3 formulations. However, the poorly immunogenic 4ED3 became almost non-immunogenic when injected after or together with 2ED3 and 3ED3, but showed slightly increased immunogenicity when injected with 1ED3, suggesting an adjuvanticity of 1ED3 on 4ED3’s immunogenicity.

Conclusions: Although DENV1~4 ED3s share similar sequence homologies and structures, their immune induction potentials differ significantly in terms of immune magnitude, sero-specificity, and sero-cross-reactivity. Such intrinsic features of DENV1~4 ED3s may lead to ‘antigen interference’, limiting both the understanding of dengue etiology and the success of dengue vaccine development, which needs to neutralize all four DENV serotypes equivalently.

Rationale: Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe complication of dengue virus infection, associated with high mortality. We report a case of a 9-week primigravida presenting with high grade fever spikes and a positive Dengue NS1 antigen. The patient exhibited worsening clinical parameters, including cytopenias.

Patient concerns: A primigravida at 9th week of gestation and this condition has limited diagnostic modalities and treatment options for HLH.

Diagnoses: HLH secondary to dengue hemorrhagic fever.

Outcomes: Intravenous steroids were initiated with monitoring of laboratory and clinical parameters. The patient recovered successfully after initiation of intravenous steroids. Oral steroids were subsequently tapered over an next eight-week period, leading to a successful recovery.

Lessons: This case is unique due to the interplay between dengue virus infection, HLH, and early pregnancy, characterized by overlapping clinical symptoms and limited treatment options. Prompt initiation of intravenous steroid therapy resulted in significant clinical improvement. This case highlights the critical importance of early identification and treatment of dengue associated HLH to reduce mortality. Furthermore, it underscores the urgent need for focused research on HLH in pregnant patients, particularly in low and middle income countries.