How to test a tick for encephalitis infection

Why Test a Tick?

Understanding Tick-Borne Diseases

Tick-borne diseases comprise infections transmitted by ixodid and argasid arthropods. Pathogens include viruses, bacteria, protozoa, and occasionally fungi. Each agent exploits the tick’s salivary secretions to enter the vertebrate host, where incubation periods and clinical manifestations differ markedly.

Encephalitic viruses, such as Powassan, TBE, and Louping‑ill, are among the most severe tick-transmitted agents. Human infection can progress to meningitis, encephalitis, or fatal neurologic disease. Surveillance of tick populations therefore informs public‑health risk assessments and guides preventive measures.

Laboratory detection of encephalitis‑causing viruses in ticks relies on molecular and serologic techniques. The workflow typically includes:

Specimen acquisition – collect questing or engorged ticks, preserve in RNAlater or dry ice, record species, life stage, and geographic coordinates.
Surface decontamination – immerse in 70 % ethanol for 30 seconds, rinse with sterile phosphate‑buffered saline to reduce external contaminants.
Tissue homogenization – macerate individual ticks in lysis buffer using bead‑beating or manual grinding; avoid cross‑contamination by processing one specimen at a time.
Nucleic acid extraction – apply silica‑column or magnetic‑bead kits optimized for low‑copy viral RNA; include extraction controls.
Amplification – perform real‑time reverse‑transcription PCR targeting conserved regions of flavivirus or orthoflavivirus genomes; employ multiplex panels when screening for multiple agents.
Confirmation – sequence positive amplicons, compare with reference databases, and submit to GenBank for verification.
Serology (optional) – conduct immunofluorescence assay or enzyme‑linked immunosorbent assay on tick homogenates to detect viral antigens; interpret alongside molecular results.

Interpretation requires awareness of assay sensitivity, tick infection prevalence, and background viral load. Positive PCR indicates the presence of viral RNA but does not confirm infectivity; virus isolation in cell culture or animal models provides definitive evidence of viable pathogen.

Safety protocols mandate biosafety level‑2 containment for handling potentially infectious ticks and specimens. Personnel must wear gloves, lab coats, and eye protection; work within a certified biosafety cabinet when performing homogenization and nucleic‑acid extraction.

Understanding the diversity of tick-borne pathogens, their transmission dynamics, and the laboratory methods for detecting encephalitic viruses equips clinicians, researchers, and public‑health officials to respond effectively to emerging threats.

Risks of Encephalitis

Encephalitis, inflammation of the brain, can result from tick‑borne viruses such as Powassan, Tick‑borne encephalitis virus, and others. Infection may progress rapidly, producing life‑threatening complications.

Key risks include:

Acute neurological failure (seizures, coma, respiratory arrest)
Permanent cognitive impairment (memory loss, reduced executive function)
Motor deficits (paralysis, coordination loss)
Vision and hearing disturbances
Fatal outcome, with mortality rates up to 20 % for some strains

Risk factors that increase the likelihood of severe disease are:

Residence or travel in endemic regions (northern Europe, parts of North America, Asia)
Exposure during peak tick activity months (spring, early summer)
Absence of personal protective measures (long clothing, repellents)
Delayed medical evaluation after a tick bite or onset of symptoms

Because the consequences of encephalitis are severe, evaluating ticks for the presence of pathogenic viruses becomes a critical step in assessing exposure risk and guiding timely clinical intervention.

Methods for Tick Testing

Home Tick Testing Kits

How They Work

Testing ticks for encephalitis‑causing viruses relies on laboratory techniques that identify viral genetic material, proteins, or viable particles. Each method operates on a distinct principle, allowing confirmation of infection even when viral loads are low.

Reverse transcription polymerase chain reaction (RT‑PCR) – RNA extracted from the tick is reverse‑transcribed into cDNA, then amplified with virus‑specific primers. Amplification indicates the presence of viral RNA, providing rapid, quantitative results.
Real‑time quantitative PCR (qPCR) – Similar to RT‑PCR, but fluorescence emitted during each amplification cycle is measured. The fluorescence threshold correlates with the initial amount of viral genome, delivering precise load estimates.
Immunofluorescence assay (IFA) – Tick homogenate is fixed on a slide, incubated with antibodies that bind viral antigens, and visualized under a fluorescence microscope. Positive fluorescence confirms antigen presence and localizes infection within tick tissues.
Virus isolation in cell culture – Homogenized tick material is inoculated onto susceptible cell lines (e.g., Vero or BHK‑21). Cytopathic effects, confirmed by subsequent immunostaining, indicate replication‑competent virus. This method validates infectivity but requires several days of incubation.
Next‑generation sequencing (NGS) – Total nucleic acids from the tick are sequenced without prior target selection. Bioinformatic analysis matches reads to known encephalitis virus genomes, uncovering co‑infections and novel strains.

The workflow typically begins with homogenization of the tick, followed by nucleic acid extraction for molecular assays or preparation of slides for IFA. Positive molecular results may be corroborated by culture or sequencing to rule out false positives and to characterize the viral strain. Together, these techniques provide a comprehensive assessment of tick‑borne encephalitis risk.

Accuracy and Limitations

Testing a tick for the presence of encephalitis‑causing viruses relies primarily on molecular assays, virus isolation, and serologic detection. The reliability of each method determines the overall accuracy of the diagnostic process, while inherent constraints shape its practical utility.

Molecular techniques, chiefly reverse‑transcription PCR, provide high sensitivity (often >95 %) for detecting viral RNA in individual ticks. Specificity exceeds 99 % when primers target conserved regions unique to the pathogen. Accuracy diminishes when viral loads fall below the assay’s limit of detection, leading to false‑negative results. Degraded RNA, improper storage, or insufficient homogenization further reduce sensitivity.

Virus isolation in cell culture offers definitive evidence of live pathogen but suffers from low throughput and prolonged turnaround (7–14 days). Success rates range from 10 % to 30 % of PCR‑positive samples, reflecting the virus’s fragility and the need for optimal culture conditions. The method’s limited sensitivity and requirement for biosafety level 3 facilities restrict routine application.

Serologic approaches, such as immunofluorescence assays, identify viral antigens within tick tissues. These tests achieve moderate sensitivity (70–80 %) and are prone to cross‑reactivity with related flaviviruses, generating false‑positive outcomes. Specificity improves when paired with confirmatory neutralization assays, but the added steps increase complexity and cost.

Key limitations common to all techniques include:

Sample quality – degradation of nucleic acids or antigens during collection, transport, or storage.
Tick species variability – differing viral loads and tissue distribution across species affect detection probability.
Temporal factors – early infection stages may not yield detectable levels; late stages may reflect cleared infection, producing negative results despite prior exposure.
Laboratory capacity – high‑throughput PCR platforms are widely available, whereas virus culture and neutralization assays require specialized infrastructure.
Interpretive ambiguity – detection of viral RNA does not confirm infectivity; conversely, absence of detectable material does not rule out exposure in the host organism.

Overall, PCR delivers the highest analytical accuracy for assessing encephalitis virus presence in ticks, yet its performance hinges on rigorous sample handling and assay design. Complementary methods, such as virus isolation and serology, provide confirmatory value but are limited by lower sensitivity, longer processing times, and potential cross‑reactivity. Recognizing these constraints is essential for interpreting test results and guiding public‑health decisions.

Professional Laboratory Testing

When to Choose Lab Testing

Laboratory analysis should be pursued when visual inspection cannot confirm the presence of encephalitic pathogens in a tick. Situations that merit testing include:

Collection from a region with documented cases of tick‑borne encephalitis (TBE) or recent outbreaks.
Acquisition from a host that exhibits neurological symptoms consistent with TBE or has been diagnosed with the disease.
Ticks found attached for more than 24 hours, increasing the likelihood of pathogen transmission.
Specimens that are part of a surveillance program aimed at monitoring TBE prevalence in vector populations.
Cases where the tick species is known to be a competent vector for TBE viruses, such as Ixodes ricinus or Ixodes persulcatus.

Testing is also advisable when epidemiological data indicate a rising incidence of TBE, when the tick is submitted for diagnostic confirmation in a clinical setting, or when the result will influence public‑health decisions, such as issuing warnings or implementing control measures. In the absence of these risk factors, routine visual identification may suffice, conserving laboratory resources for higher‑priority samples.

Types of Lab Tests

Laboratory confirmation of tick‑borne encephalitis viruses relies on direct detection of viral material or indirect evidence of infection. The choice of method depends on specimen quality, time since collection, and the laboratory’s capacity.

Polymerase chain reaction (PCR) – amplifies viral RNA from tick homogenates; real‑time formats provide quantitative results and high specificity.
Virus isolation in cell culture – inoculates tick extracts into susceptible cell lines (e.g., Vero or C6/36); yields live virus for further characterization but requires biosafety level 3 facilities and several days of incubation.
Immunofluorescence assay (IFA) – uses fluorescently labelled antibodies to detect viral antigens in fixed tick sections; useful for rapid screening when microscopy resources are available.
Enzyme‑linked immunosorbent assay (ELISA) – captures viral proteins with monoclonal antibodies; can be configured for antigen detection or for measuring seroconversion in experimental hosts.
Next‑generation sequencing (NGS) – sequences all nucleic acids in the sample, enabling identification of known and novel encephalitis viruses; provides phylogenetic information but demands sophisticated bioinformatics.
Serological tests (neutralization, hemagglutination inhibition) – assess the presence of virus‑specific antibodies in blood from animals that fed on the tick; applicable when direct viral detection fails.

Each assay has distinct performance characteristics. PCR offers the fastest turnaround and the lowest detection limit, while virus isolation confirms infectivity. IFA and ELISA provide intermediate speed with moderate sensitivity. NGS delivers comprehensive data at higher cost and complexity. Serology supplies epidemiological context but does not confirm current infection in the tick itself. Selecting the appropriate combination of tests maximizes diagnostic confidence and informs public‑health responses.

PCR Testing

PCR testing is the primary molecular method for detecting encephalitis‑causing viruses in ticks. The procedure begins with careful removal of the tick, followed by placement of the whole specimen or dissected salivary glands into a sterile tube containing lysis buffer. Immediate storage at –80 °C preserves nucleic acids until extraction.

During extraction, commercial kits or silica‑based columns isolate viral RNA. The purified RNA undergoes reverse transcription to generate complementary DNA (cDNA), which serves as the template for the amplification step. Specific primer‑probe sets target conserved regions of the viral genome, such as the NS5 gene of flaviviruses or the G gene of togaviruses. Real‑time PCR (qPCR) monitors fluorescence in each cycle, providing quantitative cycle threshold (Ct) values that indicate viral load.

Interpretation follows these criteria:

Ct < 35: positive detection of viral nucleic acid.
Ct ≥ 35: indeterminate; repeat testing recommended.
No amplification in the sample but successful amplification in the internal control: negative result.
Failure of the internal control: sample invalid, repeat extraction required.

Quality control measures include:

Positive control containing known viral RNA.
Negative extraction control to detect contamination.
No‑template control for reagent purity.

Limitations of PCR testing in tick specimens:

RNA degradation if storage conditions are inadequate.
Inhibitory substances present in tick tissue may reduce amplification efficiency.
Detection of viral genetic material does not distinguish between viable and non‑viable virus.

Safety protocols mandate biosafety level 2 practices: use of personal protective equipment, sealed workstations for nucleic acid manipulation, and decontamination of surfaces with RNase‑free solutions. Proper documentation of each step ensures traceability and compliance with laboratory accreditation standards.

Antibody Testing

Antibody testing detects immune‑reactive proteins generated by a tick infected with tick‑borne encephalitis (TBE) virus. The method relies on the presence of virus‑specific IgM and IgG that bind to viral antigens immobilized on a solid phase.

To prepare a specimen, the tick is homogenized in a sterile buffer, centrifuged, and the super‑natant is filtered. Protein concentration is measured, and an aliquot is diluted according to the assay’s recommended range.

Common formats include:

Enzyme‑linked immunosorbent assay (ELISA): plates coated with recombinant TBE envelope protein capture specific antibodies; a secondary enzyme‑conjugated antibody produces a measurable color change.
Indirect immunofluorescence assay (IFA): fixed infected cells are incubated with tick extract; bound antibodies are visualized with a fluorescent secondary antibody.
Plaque reduction neutralization test (PRNT): serial dilutions of tick extract are mixed with live TBE virus; reduction of plaque formation indicates neutralizing antibodies.

Result interpretation follows a defined cutoff. Optical density (OD) values above the established threshold in ELISA or fluorescence intensity exceeding background in IFA denote a positive finding. PRNT titers of ≥1:10 are typically considered indicative of infection. Positive IgM suggests recent exposure; IgG persistence may reflect prior infection or vaccination.

Limitations comprise cross‑reactivity with related flaviviruses, reduced sensitivity in early infection before antibody production, and the need for biosafety level‑3 facilities for live‑virus assays. Validation with reference standards, inclusion of negative and positive controls, and periodic proficiency testing ensure assay reliability.

Steps for Submitting a Tick to a Lab

Proper Tick Removal

Removing a tick correctly is essential for accurate laboratory assessment of potential encephalitic infection. Improper extraction can damage the specimen, introduce contaminants, and compromise downstream testing.

Use fine‑point tweezers or a specialized tick‑removal tool; avoid pinching the body with fingers.
Grasp the tick as close to the skin as possible, securing the mouthparts without crushing the abdomen.
Apply steady, upward pressure; pull straight out without twisting or jerking.
Inspect the bite site for retained mouthparts; if any remain, repeat the removal process with fresh tweezers.

After extraction, place the tick in a sterile, sealable container such as a 1.5 ml microcentrifuge tube. Add a small volume of RNA‑preserving solution (e.g., RNAlater) or keep the specimen on ice if immediate analysis is planned. Label the container with collection date, location, and host information. Store at –20 °C or lower until transport to the diagnostic laboratory.

Document the removal procedure, noting any difficulties or visible damage to the tick. Provide this record with the sample to assist laboratory personnel in interpreting test results for encephalitis‑related pathogens.

Tick Storage and Transportation

Ticks intended for encephalitis virus detection must be kept at temperatures that preserve nucleic acids and prevent bacterial overgrowth. Immediately after collection, place each specimen in a sterile, leak‑proof tube containing a minimal volume of RNA‑stabilizing solution or 70 % ethanol. Label tubes with date, location, and host information before sealing.

Transport conditions depend on the time interval to the laboratory:

Within 2 hours: maintain specimens on ice packs (0–4 °C) and ship in insulated containers.
Between 2 and 24 hours: store at 4 °C; avoid freezing, which can rupture tick cuticle and release inhibitors.
Longer than 24 hours: freeze at –80 °C in dry ice; use cryogenic vials that resist breakage.

During shipment, include a temperature indicator to confirm that the cold chain remained intact. Arrange rapid courier service that minimizes handling and vibration. Upon arrival, log the temperature data, then transfer ticks to –80 °C freezers until nucleic acid extraction. Any deviation from the specified temperature range should be recorded and considered when interpreting test results.

Information to Provide

When a tick is submitted for encephalitis‑related testing, the accompanying data must allow the laboratory to verify the sample, assess risk, and interpret results accurately. Provide the following information:

Species and developmental stage – Identify the tick to the species level (e.g., Ixodes scapularis) and note whether it is larva, nymph, or adult; include sex for adult specimens.
Collection date – Record the exact calendar date (YYYY‑MM‑DD).
Geographic coordinates – Supply latitude and longitude or a precise locality description (e.g., “north side of Oak Hill Trail, 38.1234 N, 77.5678 W”).
Host information – Indicate the animal or human from which the tick was removed; note the host’s health status if known.
Environmental context – Mention habitat type (forest, grassland, urban park) and any relevant weather conditions at the time of collection.
Preservation method – Specify whether the tick was stored in ethanol (concentration and volume), frozen at –20 °C, or kept dry; include duration of storage before shipment.
Packaging details – Describe container type, labeling, and any biohazard markings.
Contact information – Provide name, affiliation, phone number, and email of the person responsible for the submission.

In addition to the above, attach a brief chain‑of‑custody log if the sample passes through multiple handlers. Ensure all entries are legible, use standard abbreviations, and avoid ambiguous terms. Accurate and complete documentation enables reliable detection of encephalitis‑causing viruses in tick specimens.

Interpreting Test Results

Positive Test Results

Next Steps for Medical Consultation

After a laboratory result indicating the presence of an encephalitis‑causing virus in a tick, the patient should arrange an immediate medical consultation. The clinician will verify the diagnosis, assess exposure risk, and determine whether prophylactic treatment or monitoring is warranted.

Recommended actions during the appointment

Present the tick test report and describe any recent outdoor activities.
Provide a complete medical history, including vaccinations, immunosuppressive conditions, and current medications.
Undergo a focused neurological examination to detect early signs of central nervous system involvement.
Discuss the possibility of antiviral therapy, such as ribavirin or other agents, based on the identified virus strain.
Receive guidance on symptom surveillance, including fever, headache, neck stiffness, or altered mental status, and instructions for rapid re‑evaluation if they develop.
Obtain a schedule for follow‑up visits, typically within 48–72 hours, and a plan for additional laboratory testing (e.g., serum IgM, CSF analysis) if symptoms emerge.

The clinician’s assessment will define the precise treatment pathway and establish a monitoring protocol to mitigate the risk of severe encephalitic disease.

Treatment Options

When a tick tests positive for the encephalitis virus, clinical management shifts from diagnosis to immediate therapeutic intervention. No antiviral agent has received regulatory approval for this infection; therefore, treatment relies on supportive measures and symptom control.

Hospital admission for patients with fever, headache, or neurological signs; continuous monitoring of vital functions and mental status.
Intravenous fluid therapy to maintain hydration and electrolyte balance.
Antipyretic and analgesic medication (e.g., paracetamol, ibuprofen) to reduce fever and pain.
Antiemetic agents when nausea or vomiting occur.
Respiratory support, including supplemental oxygen or mechanical ventilation, for severe respiratory compromise.
Corticosteroid therapy may be considered in cases of pronounced cerebral edema, following specialist assessment.
Physical and occupational therapy initiated during recovery to address motor deficits and cognitive impairment.
Experimental protocols (e.g., ribavirin, interferon‑α) employed only within controlled clinical trials or compassionate‑use programs.

Long‑term follow‑up includes neuropsychological evaluation and periodic imaging to detect residual lesions. Vaccination against the virus remains the primary preventive strategy for individuals at high risk of exposure.

Negative Test Results

Continued Vigilance

Continual monitoring after initial tick screening ensures that early-stage infections are not missed. Laboratories must retain specimens for retesting if symptoms evolve, and clinicians should request repeat analyses when patients develop neurological signs within two weeks of exposure.

Key practices for maintaining vigilance include:

Documenting collection date, location, and host species for each tick sample.
Re‑examining negative results when new clinical information emerges.
Updating assay protocols in line with emerging viral strains and regulatory guidelines.
Sharing findings with regional surveillance networks to detect geographic shifts in pathogen prevalence.

Sustained attention to these measures reduces false‑negative outcomes, supports accurate public‑health reporting, and protects at‑risk populations from delayed diagnosis.

Understanding False Negatives

False‑negative results occur when a tick that carries an encephalitis‑causing virus is reported as negative by a diagnostic assay. Several mechanisms contribute to this outcome.

Laboratory variables can reduce assay sensitivity. Insufficient homogenization of tick tissue leaves viral particles unrecovered. Degradation of nucleic acid during storage, especially at temperatures above −20 °C, lowers detectable RNA levels. Inadequate primer design or mismatches between primers and viral strains cause amplification failure in PCR‑based methods. Low‑volume extraction kits may not capture the small quantity of virus present in early infection stages.

Biological factors also affect detection. Viral load in a tick fluctuates during its life cycle; early‑stage infection often yields concentrations below the limit of detection. Co‑infection with other microorganisms may inhibit target amplification or compete for reagents. Some tick species harbor inhibitors, such as hemoglobin or polysaccharides, that interfere with enzymatic reactions.

Mitigation strategies include:

Process whole ticks or pool multiple specimens to increase total viral input.
Use validated extraction protocols that incorporate inhibitor removal steps.
Store samples immediately at −80 °C and limit freeze‑thaw cycles.
Employ multiplex assays with primers covering known genetic diversity of encephalitis viruses.
Apply quantitative PCR or digital PCR to improve detection of low‑copy targets.
Incorporate internal controls to flag inhibition or extraction failures.

Understanding these sources of false negatives enables laboratories to refine protocols, reduce under‑reporting, and improve surveillance of tick‑borne encephalitis pathogens.

Prevention and Awareness

Tick Bite Prevention Strategies

Repellents and Protective Clothing

Effective tick avoidance reduces the risk of acquiring encephalitis‑causing viruses before specimens are collected for laboratory analysis.

Repellents applied to skin or exposed clothing create a chemical barrier that deters attachment. High‑efficacy options include:

DEET (N,N‑diethyl‑meta‑toluamide) at 20‑30 % concentration; protection lasts 4–6 hours, reapply after sweating or water exposure.
Picaridin (KBR 3023) at 20 %; comparable duration to DEET with a milder odor.
IR3535 (ethyl butylacetylaminopropionate) at 20 %; effective for up to 6 hours, suitable for children over 2 years.
Permethrin‑treated fabric; 0.5 % concentration applied to clothing, remains active after multiple washes, kills ticks on contact.

Protective clothing provides a physical shield that complements chemical repellents. Recommended specifications:

Long‑sleeved shirts and full‑length trousers made of tightly woven material; tuck shirts into pants and pants into socks.
Light‑colored garments to facilitate visual detection of attached ticks.
Footwear that covers ankles; consider gaiters for additional coverage.
Treat all outerwear with permethrin according to manufacturer instructions; avoid direct skin contact with the insecticide.

Field personnel should apply skin repellent before entering tick‑infested areas, wear permethrin‑treated clothing, and conduct a systematic body inspection at the end of each exposure period. Removing and laundering clothing promptly preserves the residual insecticidal effect.

Combining appropriate repellents with rigorously selected clothing minimizes tick bites, thereby supporting accurate and safe collection of specimens for encephalitis virus testing.

Tick Checks

Tick checks are the first practical step in evaluating a specimen for potential encephalitic viral infection. Proper removal, preservation, and documentation of the tick create reliable material for downstream laboratory analysis.

The process begins with a thorough visual inspection of the skin, clothing, and hair. Use a fine‑toothed comb or gloved fingers to locate attached arthropods. Once identified, grasp the tick as close to the host’s skin as possible with fine tweezers, applying steady upward pressure to avoid crushing the mouthparts. Detach the tick in a single motion, place it in a labeled, sealable container, and store at 4 °C if processing within 24 hours or at –20 °C for longer intervals.

Key documentation elements include:

Date and time of removal
Geographic location (GPS coordinates or detailed description)
Host species and anatomical site of attachment
Tick developmental stage and estimated engorgement level

Preserve the specimen in 70 % ethanol for morphological identification or in RNAlater for molecular assays. After identification, submit the tick to a certified laboratory equipped to detect encephalitis‑associated viruses such as Powassan, tick‑borne encephalitis, or other flaviviruses. The laboratory will perform nucleic acid extraction followed by RT‑PCR or next‑generation sequencing, using the preserved specimen as the source material.

Accurate tick checks reduce false‑negative results by ensuring that the specimen is intact, correctly identified, and appropriately stored before virological testing.

Awareness of Symptoms

Early Signs of Encephalitis

Early manifestation of encephalitis often precedes severe neurological decline and guides decisions about tick‑borne pathogen assessment. Recognizing these symptoms enables timely specimen collection from the vector and appropriate laboratory analysis.

Typical initial indicators include:

Sudden fever exceeding 38 °C
Severe headache unresponsive to analgesics
Nausea or vomiting without gastrointestinal cause
Photophobia or marked sensitivity to light
Altered mental status such as confusion, disorientation, or lethargy
Neck stiffness suggesting meningeal irritation
Focal weakness or tingling in limbs

When any of these signs appear after a tick bite, clinicians should request serologic or molecular testing of the removed tick to confirm the presence of encephalitic viruses. Early detection of the pathogen shortens the interval to antiviral therapy and reduces the risk of long‑term neurological sequelae.

When to Seek Medical Attention

After a tick bite, immediate medical evaluation is warranted if any of the following conditions are present:

Fever exceeding 38 °C (100.4 °F) within two weeks of exposure.
Severe headache, neck stiffness, or photophobia.
Rapidly progressing neurological deficits such as weakness, loss of coordination, or altered consciousness.
Persistent vomiting, seizures, or confusion.
Signs of a rash that expands rapidly, becomes necrotic, or is accompanied by swelling at the bite site.

Seek care promptly when the bite occurs on a high‑risk area (e.g., scalp, groin) or when the tick remained attached for more than 24 hours, as prolonged attachment increases pathogen transmission. Individuals with compromised immune systems, chronic illnesses, or a history of previous central nervous system infections should obtain medical advice even in the absence of overt symptoms.

If none of the above manifestations appear, schedule a follow‑up appointment within 7–10 days to discuss laboratory testing and possible prophylactic treatment. Early intervention minimizes the risk of encephalitic complications and improves outcomes.