Mosquito-borne Disease Information for Providers

On June 26, 2023, the CDC published a Health Advisory (https://emergency.cdc.gov/han/2023/pdf/CDC_HAN_494.pdf) to share information about locally acquired malaria cases identified in the United States (specifically, Texas and Florida).

The Georgia Department of Health is taking this news seriously and enhancing investigations for suspected malaria cases and we hope providers will too. Please consider the diagnosis of malaria in any person with a fever of unknown origin, regardless of international travel history, particularly if they have been to the areas with recent locally acquired malaria.

Clinical manifestations of malaria are non-specific and include fever, chills, headache, myalgias, and fatigue. Nausea, vomiting, and diarrhea may also occur. For most people, symptoms begin 10 days to 4 weeks after infection, although a person may feel ill as early as 7 days or as late as 1 year after infection. Malaria is a medical emergency and should be treated accordingly. Patients with a high index of suspicion for malaria should be urgently evaluated in a facility that is able to provide rapid diagnosis and treatment, within 24 hours of presentation. Order microscopic examination of thin and thick blood smears, and a rapid diagnostic test (RDT) if available, to diagnose malaria as soon as possible.

Some information to keep in mind:

• Although we have a mosquito species that can transmit malaria, Georgia has not had any documented cases of local transmission in over 20 years (since 1999).
• The human cases and malaria-positive mosquitos reported in Florida are not in counties bordering Georgia; we do not consider these cases a direct threat to our mosquito population.
• Our malaria case counts were lower in 2020/2021 due to travel restrictions and hesitations brought about by the COVID pandemic. However, both 2022 and 2023 (preliminary) appear to be standard years with no unusual spikes in case counts.

Travel Health Notices inform travelers and clinicians about current health issues that should be discussed before patients travel. Advisories and notices can be searched in multiple ways. Search information by:

• Destination [external]
• Recent Notices [external]
• CDC Yellow Book [external]

When suspecting an arboviral disease case, several key signs and symptoms should be considered. The following are common indicators to look for:

1. Fever: Arboviral diseases often present with high fever, which may appear suddenly and persist for several days or longer.

2. Headache: Headaches are a frequent symptom of arboviral infections and can range from mild to severe.

3. Muscle and Joint Pain: Patients may experience myalgia and arthralgia, which can be generalized or localized to specific areas of the body.

4. Fatigue and Malaise: Generalized fatigue, weakness, and malaise are commonly observed in arboviral infections.

5. Rash: Some arboviral diseases may cause a rash, although it is not a consistent symptom for all cases. The rash can vary in appearance, from maculopapular to petechial.

6. Neurological Symptoms: In severe cases, arboviral diseases can affect the central nervous system, leading to neurological symptoms such as meningitis, encephalitis, confusion, disorientation, seizures, and even coma.

It's important to note that these symptoms are not specific to any particular arboviral disease. They can also be present in other viral infections or medical conditions. Therefore, a thorough medical evaluation by a healthcare professional, along with appropriate laboratory testing, is necessary to confirm a diagnosis. Early diagnosis and appropriate management are crucial for favorable outcomes in arboviral infections.

For more information on the clinical evaluation of specific diseases, please refer to information below:

Chikungunya [external link]

Dengue [external link]

Eastern Equine Encephalitis [external link]

Malaria [external link]

West Nile virus [external link]

Zika [external link]

Arboviral testing is useful as a diagnostic and surveillance tool. Although commercial testing for arboviral antibodies is common, the Georgia Department of Public Health Laboratory (GPHL) can perform confirmatory testing on certain mosquito-borne diseases. Alternatively, GPHL can also forward samples to the CDC for testing. Due to limited resources, specimens will not be tested by GPHL or CDC unless they meet the testing criteria. Please call the Georgia Department of Public Health (404-657-2588) for assistance with submitting specimens for testing and to obtain the proper submission codes. The following information does not pertain to rabies specimen submissions. 

Prior to submission, please have the following information available:

• Patient name (first and last)
• Patient date of birth
• Patient county of residence (please contact epidemiology if submitting an out of state patient)
• Pregnancy status (for Zika samples)
• Travel dates and locations
• Clinical symptoms and onset date
• Collection date
• Phone and fax numbers of contact at the sending facility

Please note the following before submission:

• CLIA regulations require two primary identifiers on the specimen container to match information on the forms. If there is an error on the forms, please shred the incorrect forms and contact the sender for corrected copies. Samples sent that do not meet CLIA regulations may have testing delayed or be discarded.
• GPHL does not accept vectors for testing. Please contact Environmental Health for information on vector identification.
• Samples sent to GPHL or CDC without preapproval from epidemiology or without proper forms may be discarded or results may be held (this does not apply to Malaria samples).

Documents for submission to the Georgia Public Health Laboratory (GPHL)

• GPHL Lab Submission Form  (Form 3583; Revised 06/2022)

Samples should be stored at 4-8°C for a maximum of 7 days. Send samples with matching requisition forms Monday – Thursday overnight on ice or via courier to avoid weekend (and holiday) deliveries to:

Georgia Public Health Laboratory
ATTN: SAMPLES
1749 Clairmont Road
Decatur, GA 30033
Phone: 404-327-7900

Sending facilities are responsible for the cost of shipping to the state laboratory.

Documents for submission to the CDC

All samples submitted to the CDC must be processed at GPHL. Please fill out the GPHL Lab Submission Form and select the appropriate CDC send-out box.

• CDC Test Directory [external]
• CDC Specimen Submission Form [external]

National Surveillance Data - ArboNET

ArboNET is the national arboviral surveillance system managed by CDC and state health departments. In addition to human disease, ArboNET maintains data on arboviral infections among presumptive viremic blood donors, veterinary disease cases, mosquitoes, dead birds, and sentinel animals.

Reporting an Arboviral disease case

Positive laboratory results are routinely reported to DPH. However, if you have a patient that you suspect has an arboviral disease, please use this link to determine the best method to report to DPH.

Diagnosis and Management of West Nile Virus Infection: A Case-Based Approach

CME / ABIM MOC / CE

Valid for credit through: 4/4/2024

A recent CDC survey found that only a small percentage of clinicians surveyed could correctly identify how to properly diagnose WNV disease. After taking this training, clinicians will be able to correctly identify risk factors and symptoms as well as diagnose and prevent West Nile virus disease.