The presence of Plasmodium malariae and Plasmodium knowlesi in near malaria elimination setting in western Indonesia.

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.

SARS-CoV-2 lineages circulating during the first wave of the pandemic in North Sumatra, Indonesia.

Objectives: To determine the lineage distribution of the virus during the first wave of the pandemic in North Sumatra, Indonesia. Methods: A total of 20 samples with positive results based on reverse transcription-polymerase chain reaction were selected for virus culture and then performed whole-genome sequence analysis using next-generation sequencing which was applied by the Illumina MiSeq instrument. Results: Whole-genome sequence analysis revealed that the majority of our samples belong to lineages B.1.468 (n = 10), B.1 (n = 5), B.1.1 (n = 2), B.1.1.398 (n = 2), and B.6 (n = 1). Other unique amino acid mutations found in our samples were present in A58T on non-structural protein (NSP3) (70%), P323L on NSP12 (95%), Q57H on NS3 protein (75%), and D614G on S (100%). Conclusion: The SARS-CoV-2 lineage B.1.468 may be the main virus variant circulating in North Sumatra at the beginning of the emergence of COVID-19 cases in this province.

Use of saliva as an alternative diagnostic method for diagnosis of COVID-19.

Background: Mass population testing has been recommended to contain the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, the use of nasopharyngeal swab specimens has caused many logistic challenges. This study investigated the sensitivity and specificity of saliva as a non-invasively-obtained specimen for molecular detection of SARS-CoV-2 RNA. Methods: In total, 153 patients with confirmed coronavirus disease 2019 (COVID-19) who had been admitted to the regional referral hospital or who self-isolated at home were included in this study. Nasopharyngeal swab specimens and saliva samples were collected on the same day, and were tested for SARS-CoV-2 infection using reverse transcriptase polymerase chain reaction. Results: The sensitivity and specificity of saliva samples were 81.5% and 76.4%, respectively, in cases that had been confirmed as COVID-19 using nasopharyngeal swab samples. Positive predictive values and negative predictive values were 92.3% and 54.1%, respectively. The highest detection rates were found among samples collected 4-7 days since symptom onset. Conclusion: Saliva samples showed comparable performance to nasopharyngeal swab specimens for the diagnosis of COVID-19 in adults. The performance of saliva as a diagnostic specimen for COVID-19 testing is particularly significant during the first week of symptoms.