A cluster-randomized, placebo-controlled trial to evaluate the efficacy of a spatial repellent (Mosquito Shield™) against Aedes-borne virus infection among children ≥ 4-16 years of age in the Gampaha District, Sri Lanka: study protocol (the AEGIS program).

BACKGROUND: Spatial repellents (SRs) have been widely used for prevention of mosquito bites, but their efficacy in reducing Aedes-borne viruses (ABV) has not been tested rigorously at large scale in Asia. To address this knowledge gap, a trial to evaluate the efficacy of Mosquito Shield™, a transfluthrin SR, was developed in Gampaha District of Sri Lanka across three Medical Officer of Health areas; i.e., Negombo, Wattala, and Kelaniya. METHODS: This trial is a cluster-randomized, placebo-controlled, double-blinded clinical trial. A total of ~14,430 subjects aged ≥ 6 months in 30 clusters (15 intervention, 15 placebo) from ~3900 households (HH) will be randomly selected for enrolment into a "febrile surveillance cohort." A subset of the surveillance cohort, ~3570 subjects aged ≥4-16 years that test seronegative (naïve) or are serologically positive for a previous single dengue virus (DENV) infection (monotypic) at baseline sampling, will be enrolled into a "longitudinal cohort" for measuring DENV infection based on laboratory-confirmed seroconversion during the trial. Persons identified positive for antibodies against multiple DENV serotypes (multitypic) at baseline will be monitored for secondary analyses. Active ABV disease will be assessed using an enhanced passive surveillance system with case ascertainment performed in designated healthcare facilities. Serum samples will be taken from longitudinal cohort subjects within 1-2 weeks of when intervention is first deployed (T0) with additional samples taken ~12 (T1) and ~24 months (T2) from baseline sampling. DENV seroconversion and ABV active disease rates from baseline (pre-intervention) and follow-up (post-intervention) samples will be compared between intervention and placebo clusters. Participating houses will be monitored entomologically (indoor adult Aedes aegypti population densities and adult female blood fed status) within 3 months before intervention deployment and monthly during the intervention phase. Entomological surveys will monitor indoor adult Ae. aegypti population densities and blood fed status. Dengue incidence in each cohort will be estimated and compared to determine the public health benefit of using an SR. Entomological parameters will be measured to determine if there are entomological correlates of SR efficacy that may be useful for the evaluation of new SR products. DISCUSSION: The trial will serve as an efficacy assessment of SR products in South Asia. Results will be submitted to the World Health Organization Vector Control Advisory Group for assessment of public health value towards an endorsement to recommend inclusion of SRs in ABV control programs. TRIAL REGISTRATION: Sri Lanka Clinical Trial Registry SLCTR /2022/018. Registered on July 1, 2022. CLINICALTRIALS: gov NCT05452447 . Registered on July 11, 2022. The Universal Trial Number is U1111-1275-3055.

Significance of Neuronal Autoantibodies in Comparison to Infectious Etiologies among Patients Presenting with Encephalitis in a Region with a High Prevalence of Infections.

Background: Prevalence of antibody-mediated autoimmune encephalitis (AE) is reported to be comparable to infectious encephalitis in Western populations. We evaluated the frequency and significance of AE and neuronal autoantibodies in comparison to infectious etiologies among patients presenting with encephalitis in a South Asian population. Methods: Ninety-nine consecutive patients with a clinical diagnosis of encephalitis/meningoencephalitis admitted to two of the largest tertiary-care hospitals in Sri Lanka were studied. PCR and ELISA were used to screen viruses while Gram stain and culture were used to screen bacteria. Sera were tested for antibodies binding to primary embryonic rat hippocampal neuronal cultures and cell-based assays for antibodies to NMDAR, LGI1, CASPR2, Contactin2, AMPAR, GABAAR, GABABR, aquaporin-4 and MOG. Results: Patient ages ranged from 1 month to 73 years (mean = 24.91; SD = 21.33) with a male: female ratio of 1.75:1. A viral etiology was identified in 27.3% and bacterial meningoencephalitis was diagnosed in 17.1%. Sera of nine patients had antibodies binding to live primary neurons, but only five had specific antibodies to CASPR2 (n = 1), NMDAR (n = 2) or GABABR-antibodies (n = 2). Moreover, the patients with CASPR2 antibodies and NMDAR-antibodies were also positive for dengue antibodies. Only the two patients with NMDAR-antibodies had features and responses to immunotherapy consistent with AE. Conclusions: Identified infectious forms of meningoencephalitis (44.4%) greatly exceeded the occurrence of neuronal autoantibodies (9.1%) and AE (2%) in Sri Lanka, and this may be common in those regions where infections are prevalent.

Autoimmune encephalitis in a South Asian population.

BACKGROUND: Autoimmune encephalitis (AE) is now considered a main, potentially curable cause of encephalitis, but remains conspicuously underreported from South Asia. We studied the clinical characteristics in relation to their antibody status and outcomes of patients presenting with AE in Sri Lanka. METHODS: Patients admitting to government hospitals who were clinically suspected of AE by an on-site neurologist were prospectively recruited over a period of 12 months. Sera and cerebrospinal fluid were tested for NMDAR, AMPAR1, AMPAR2, LGI1, CASPR2, GABARB1/B2 antibodies (Ab) using commercial cell-based assays. Demographic, clinical and laboratory data were compiled into an investigator-administered proforma. Patients were reviewed at 1 year follow up either in person or via telephone. RESULTS: One-hundred and forty-two patients from 21 of 25 districts in Sri Lanka (median age = 20.5 years; range 1-86 years; females = 61.3%) were recruited. Of them, 65 (45.8%; median age = 19 years; range 1-86 years; females = 64.6%) fulfilled diagnostic criteria for probable NMDAR-antibody encephalitis (NMDARE) and 6 (4.2%; median age = 44 years; range 28-71 years; females = 83.3%) limbic encephalitis (LE). Abnormal behaviour (95.3%), seizures (81.5%) and movement disorders (69.2%) were the most frequent clinical manifestations of probable NMDARE. NMDAR-antibodies were detectable in 29 (44.6%) and not detectable in 36 in CSF of probable-NMDARE patients. Abnormal EEG was more frequent (p = 0.003) while a worse outcome (OR = 2.78; 95% CI = 0.88-9.09) and deaths (OR = 2.38; 95% CI = 0.67-8.33) were more likely in antibody-negative than antibody-positive probable-NMDARE. Most patients with LE had amnesia (50%) and/or confusion (100%) with agitation (83.3%) and seizures (100%) but none had detectable antibodies to any of the antigens tested. CONCLUSIONS: NMDARE is the commonest type of AE among South Asians as is the case worldwide. Clinical presentations of NMDARAb-positive and NMDARAb-negative AE patients do not significantly differ but EEG may be a useful marker of an autoimmune basis for psychiatric symptoms.

Hydroxychloroquine for post-exposure prophylaxis of COVID-19 among naval personnel in Sri Lanka: study protocol for a randomized, controlled trial.

BACKGROUND: The first case of a coronavirus 2019 (COVID-19) infection in a Sri Lankan was reported on March 11, 2020. The situation in Sri Lanka changed with the rapid increase of personnel contracting COVID-19 in a naval base camp that housed more than 4000 people. This provided a unique opportunity to study the effectiveness of hydroxychloroquine (HCQ) for post-exposure prophylaxis (PEP), while taking stringent, non-pharmacologic, public health measures to prevent spread. Our aim is to study the effectiveness and safety of HCQ for PEP among naval personnel with exposure to COVID-19-positive patients. METHODS/DESIGN: This is a placebo-controlled, randomized, clinical trial carried out in the naval base camp and quarantine centers of the Sri Lanka Navy, Ministry of Defense, Sri Lanka. Navy personnel who are exposed to a patient with confirmed COVID-19 infection but test negative for the virus on reverse real-time polymerase chain reaction (rRT-PCR) at recruitment will be randomized, 200 to each arm, to receive HCQ or placebo and monitored for the development of symptoms or rRT-PCR positivity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus for 14 days. DISCUSSION: This trial will provide high-quality evidence of the effectiveness and safety of HCQ as PEP for COVID-19. The study design is unique due to the circumstances of the outbreak in a confined area among otherwise healthy adults, at a relatively early stage of its spread. TRIAL REGISTRATION: Sri Lanka Clinical Trials Registry (SLCTR) SLCTR/2020/011 . Registered on 04 May 2020.

Miller Fisher syndrome developing as a parainfectious manifestation of dengue fever: a case report and review of the literature.

BACKGROUND: Although dengue viral infections have emerged as one of the most important mosquito-borne diseases, neurological manifestations of dengue infections are uncommon. Guillain-Barré syndrome and Miller Fisher syndrome have been reported to occur as immune-mediated complications following dengue infection. We report the case of a patient who developed Miller Fisher syndrome during the acute phase of dengue fever suggesting that Miller Fisher syndrome may arise as a result of direct neurotropism of the dengue virus. CASE PRESENTATION: A 70-year-old Sri Lankan man with well-controlled diabetes mellitus and hypertension presented with fever of 3 days' duration, drooping of eyelids, dysarthria, and unsteady gait. He developed bilateral asymmetric partial ptosis, complete external ophthalmoplegia, bilateral palatal palsy, unilateral tongue weakness, ataxia, and areflexia from the second day of illness. He did not have limb weakness. He had evidence of acute dengue infection including progressive thrombocytopenia and leukopenia, positive dengue non-structural protein 1 antigen, dengue immunoglobulin M antibodies, and polymerase chain reaction detection of dengue virus genome in serum. Magnetic resonance imaging of his brain and cerebrospinal fluid analysis were normal. Polymerase chain reaction for dengue virus and immunoglobulin M antibodies in cerebrospinal fluid were negative. Nerve conduction studies showed axonal neuropathy. Antibodies (immunoglobulin G, immunoglobulin M, and immunoglobulin A) against GQ1b and GT1a were negative. He was treated with intravenously administered immunoglobulins and a recommended fluid regimen for dengue fever. He made a complete recovery from dengue fever in 7 days and Miller Fisher syndrome in 20 days. CONCLUSIONS: This case report highlights the rare occurrence of Miller Fisher syndrome during the acute phase of dengue fever. Neurological manifestations may occur as a consequence of direct neurotropism of dengue virus.

Cytotoxic and Apoptotic Effects of Govaniadine Isolated from Corydalis govaniana Wall. Roots on Human Breast Cancer (MCF-7) Cells.

Current breast cancer therapies have limitations in terms of increased drug resistance resulting in short-term efficacy, thus demanding the discovery of new therapeutic agents. In this study, cytotoxic activity and apoptotic effects of govaniadine isolated from Corydalis govaniana Wall. roots were determined on human breast cancer (MCF-7) cells. The SRB assay result revealed that govaniadine led to dose- and time-dependent cytotoxic effect in MCF-7 cells along with less cytotoxicity against MCF-10A cells. Govaniadine-induced apoptosis was also accompanied by upregulation of Bax, p53, and Survivin mRNA expression as assessed by real time PCR analysis. Flow cytometric analysis with Annexin V and PI staining indicated that govaniadine is a potent inducer of apoptosis in MCF-7 cell lines. Distinctive morphological changes contributed to apoptosis and DNA laddering were observed in govaniadine-treated MCF-7 cells. Caspase-7 was significantly activated in treated MCF-7 cells. Govaniadine-treated MCF-7 cells also showed enhanced levels of intracellular reactive oxygen species (ROS) and glutathione S-transferase (GST) and decreased levels of glutathione (GSH). The results indicate that govaniadine has potent and selective cytotoxic effects against MCF-7 cells and the potential to induce caspase 7 dependent apoptosis in MCF-7 cells by activation of pathways that lead to oxidative stress.

Viral aetiologies of acute encephalitis in a hospital-based South Asian population.

BACKGROUND: The aetiological spectrum of acute encephalitis shows inter- and intra-geographical variations. We aimed to identify the viruses that cause infectious encephalitis in Sri Lanka, which represents a South Asian population. METHODS: A cross-sectional study was conducted among 99 patients with encephalitis/meningoencephalitis admitted to two tertiary-care hospitals in Colombo. Cerebrospinal fluid and serum were tested for conventional and emerging encephalitogenic viruses. Specific nucleic acid amplification and antibody assays were used to identify viruses. Plaque reduction neutralization test was done to confirm the diagnosis of West Nile virus (WNV). RESULTS: Patients' age ranged from 1 month to 73 years (mean = 24.91; SD = 21.33) with a male:female ratio of 1.75:1. A viral aetiology was identified in only 27.3%. These included dengue virus (40.7%), Japanese encephalitis virus (25.9%), varicella zoster virus, WNV and probable Epstein Barr virus (11.1% each). None were positive for herpes simplex viruses or cytomegalovirus. Screening for bacterial aetiologies was negative for all patients. There were no distinguishable clinical or laboratory findings between the different viral aetiologies. The case fatality rate was 7%, which was higher among patients with an identified viral aetiology. CONCLUSIONS: A viral aetiology was identified in only about a quarter of patients with encephalitis. Dengue virus accounted for the majority.