BACKGROUND: Soil-transmitted helminth (STH) infection remains of public health importance, particularly in developing countries. North Sumatra province of Indonesia has reported high prevalences of STH in many of its districts. AIM: In this study, we aimed to determine the prevalence of STH and evaluated STH knowledge and risk behaviours of school children in Mandailing Natal district. METHODS: We conducted a cross-sectional study in two primary schools in Mandailing Natal district, North Sumatera province, Indonesia. Data were collected directly from the subjects using a questionnaire after receiving consent from their parents. A stool sample was also collected to determine the STH status of each subject. Samples were then transported to the parasitology laboratory at Universitas Sumatera Utara in Medan to be analysed by a trained analyst. Kato-Katz method was used to prepare the slides (World Health Organization, 2002). The intensity of infection is classified into light, moderate and heavy infection. RESULTS: Prevalences of STH infections were 76.8% and 87.2% in Singkuand and Sikapas primary schools, respectively. The majority of infections were Ascaris lumbricoides and Trichuris trichiura at a light intensity. Only small numbers of children in the two schools used soap before eating, used soap after defecating, and wear sandal/shoes when walking outdoor. Less than 50% of children also knew the route of transmission of STH. Poorer knowledge and behaviours were shown in children from Sikapas than in Singkuang. CONCLUSION: High prevalence and poor hygiene behaviours found in this study reinforce the need to identify the correct intervention to address this STH problem in the region.

The COVID-19 pandemic has caused disruption to healthcare access worldwide and has impacted basic childhood immunization services. A decline in immunization coverage can cause immunity gaps and lead to outbreaks of vaccine-preventable diseases. Our study evaluated the association between mothers’ knowledge, attitude, and behavior regarding immunization and child immunization status during the COVID-19 pandemic in Medan, Indonesia. An analytical cross-sectional study was conducted from April to November 2021. Mothers with children aged 0–12 months were interviewed about their knowledge, attitude, and behavior regarding immunization, and their child's immunization status. Of 196 participants, 46.5% had low knowledge on immunization, 41.3% had a negative attitude, and 20.4% had negative behavior. Only 62.8% of participants had children with a complete vaccination status, and mothers with moderate knowledge (OR 2.65, 95% CI 1.08–6.61), negative attitude (OR 5.33, 95% CI 2.71–10.59), and negative behavior (OR 7.88, 95% CI 3.36–19.47) were more likely to not vaccinate their children. Mothers’ attitude, behavior, and educational background were associated with child immunization status. Recovery efforts to improve immunization coverage are urgently needed, and should include efforts to reduce mothers’ hesitancy regarding child vaccination during the pandemic.

Background: Indonesia is progressing towards malaria elimination. To achieve this goal, intervention measures must be addressed to cover all Plasmodium species. Comprehensive control measures and surveillance programmes must be intensified. This study aims to determine the prevalence of microscopic and submicroscopic malaria in Langkat district, North Sumatera Province, Indonesia. Methods: A cross-sectional survey was conducted in six villages in Langkat district, North Sumatera Province in June 2019. Data were recorded using a standardized questionnaire. Finger pricked blood samples were obtained for malaria examination using rapid diagnostic test, thick and thin blood smears, and polymerase chain reaction. Results: A total of 342 individuals were included in the study. Of them, one (0.3%) had a microscopic Plasmodium malariae infection, no positive RDT examination, and three (0.9%) were positive for P. malariae (n = 1) and Plasmodium knowlesi (n = 2). The distribution of bed net ownership was owned by 40% of the study participants. The participants had a house within a radius of 100–500 m from the forest (86.3%) and had the housing material of cement floor (56.1%), a tin roof (82.2%), wooden wall (35.7%), bamboo wall (28.1%), and brick wall (21.6%). Conclusion: Malaria incidence has substantially decreased in Langkat, North Sumatera, Indonesia. However, submicroscopic infection remains in the population and may contribute to further transmission. Surveillance should include the detection of microscopic undetected parasites, to enable the achievement of malaria elimination.

Rapid diagnostic tests (RDTs) play a critical role in malaria diagnosis and control. The emergence of Plasmodium falciparum parasites that can evade detection by RDTs threatens control and elimination efforts. These parasites lack or have altered genes encoding histidine-rich proteins (HRPs) 2 and 3, the antigens recognized by HRP2-based RDTs. Surveillance of such parasites is dependent on identifying false-negative RDT results among suspected malaria cases, a task made more challenging during the current pandemic because of the overlap of symptoms between malaria and COVID-19, particularly in areas of low malaria transmission. Here, we share our perspective on the emergence of P. falciparum parasites lacking HRP2 and HRP3, and the surveillance needed to identify them amid the COVID-19 pandemic.

Background: Zoonotic P. knowlesi and P. cynomolgi symptomatic and asymptomatic infections occur across endemic areas of Southeast Asia. Most infections are low-parasitemia, with an unknown proportion below routine microscopy detection thresholds. Molecular surveillance tools optimizing the limit of detection (LOD) would allow more accurate estimates of zoonotic malaria prevalence. Methodology/Principal findings: An established ultra-sensitive Plasmodium genus quantitative-PCR (qPCR) assay targeting the 18S rRNA gene underwent LOD evaluation with and without reverse transcription (RT) for P. knowlesi, P. cynomolgi and P. vivax using total nucleic acid preserved (DNA/RNA Shield) isolates and archived dried blood spots (DBS). LODs for selected P. knowlesi-specific assays, and reference P. vivax- and P. cynomolgi-specific assays were determined with reverse transcription (RT). Assay specificities were assessed using clinical malaria samples and malaria-negative controls. The use of reverse transcription improved Plasmodium species detection by up to 10,000-fold (Plasmodium genus), 2759-fold (P. knowlesi) and 1000-fold (P. vivax and P. cynomolgi). The Kamau et al. Plasmodium genus RT-qPCR assay was highly sensitive for P. knowlesi detection with a median LOD of ≤0.0002 parasites/μL compared to 0.002 parasites/μL for P. cynomolgi and P. vivax. The LODs with RT for P. knowlesi-specific PCRs were enhanced for the Imwong et al. 18S rRNA (0.0007 parasites/μL) and Divis et al. real-time 18S rRNA (0.0002 parasites/μL) assays, but not for the Lubis et al. hemi-nested SICAvar (1.1 parasites/μL) and Lee et al. nested 18S rRNA (11 parasites/μL). The LOD for P. vivax- and P. cynomolgi-specific assays with RT were moderately improved at 0.02 and 0.002 parasites/μL, respectively (1000-fold change). For DBS P. knowlesi samples the use of RT also markedly improved the Plasmodium genus qPCR LOD from 19.89 to 0.08 parasites/μL (249-fold change); no LOD improvement was demonstrated in DBS archived beyond 6 years. The Plasmodium genus and P. knowlesi-assays were 100% specific for Plasmodium species and P. knowlesi detection, respectively, from 190 clinical infections and 48 healthy controls. Reference P. vivax-specific primers demonstrated known cross-reactivity with P. cynomolgi. Conclusions/Significance: Our findings support the use of an 18S rRNA Plasmodium genus qPCR and species-specific nested PCR protocol with RT for highly-sensitive surveillance of zoonotic and human Plasmodium species infections.

: Malaysia has maintained zero cases of indigenous human malaria since 2018. However, zoonotic malaria is still prevalent in underdeveloped areas and hard-to-reach populations. This study aimed to determine the prevalence of malaria among remote indigenous communities in Peninsular Malaysia. A cross-sectional survey was conducted in six settlements in Kelantan state, from June to October 2019. Blood samples were tested for malaria using microscopy and nested polymerase chain reaction (nPCR) targeting the Plasmodium cytochrome c oxidase subunit III (cox3) gene. Of the 1,954 individuals who appeared healthy, no malaria parasites were found using microscopy. However, nPCR revealed seven cases of Plasmodium knowlesi mono-infection (0.4%), and six out of seven infections were in the group of 19 to 40 years old (P = 0.026). No human malaria species were detected by nPCR. Analysis of the DNA sequences also showed high similarity that reflects common ancestry to other P. knowlesi isolates. These findings indicate low submicroscopic P. knowlesi infections among indigenous communities in Malaysia, requiring PCR-based surveillance to support malaria control activities in the country.