Kara Lichtenberg - SLP - Dengue by Kara Lichtenberg

Week 1: History of Dengue

klich2807 — 2025-08-31 23:13:57 UTC

When and where dengue originated is hazy. However, the first confirmed cases of fever caused by dengue occurred in 1779 in the continents Asia, Africa, and North America (simultaneously). Benjamin Rush documented identified and named the agent in 1789.

Similarly, there was an epidemic in 1635 that presented the same symptoms as those caused by dengue, but this was not confirmed as a dengue outbreak. This epidemic happened in Guadalupe and Martinque in the West Indies.

https://www.denguevirusnet.com/history-of-dengue.html

https://health-desk.org/articles/what-is-dengue-and-where-did-it-originate-from

Week 2: Evolution and Phylogeny

klich2807 — 2025-09-02 00:52:14 UTC

Dengue is a virus is made of single stranded RNA. It is part of the Flavivirus genus. There are four stereotypes of dengue including DENV-1, DENV-2, DENV-3, and DENV-4. All four types of the virus are spread to humans through mosquitos which are classified as Aedes aegypti and Aedes Albopictus.

The virus likely began spreading in the 17th century in few countries. Now, the virus is present in over 100 countries and can spread quickly.

https://pmc.ncbi.nlm.nih.gov/articles/PMC9610151/

https://www.dengue.com/origin-and-history-dengue-virus

https://www.nature.com/articles/srep45505

Week 3: Classification

klich2807 — 2025-09-10 23:32:19 UTC

Dengue is a mosquito-borne illness classified into two categories based on the symptoms and circumstances associated with the infection. These include dengue and severe dengue. Dengue is reported when an individual lives in an area or has traveled to an area where dengue is prevalent. This can be split into two subcategories: dengue without warning signs and dengue with warning signs. This means that some people will be asymptomatic if they contract dengue, while others may experience minor symptoms. Severe dengue is defined when an individual experiences symptoms including plasma leakage, respiratory distress, severe bleeding, severe organ impairment, heart impairment, and unconsciousness.

Dengue is not present in Bergey's Manual.

The classification of dengue is as follows:

Genus: Flavivirus

Family: Flaviviridae

https://www.cdc.gov/dengue/hcp/clinical-signs/guidelines.html

https://microbenotes.com/bergeys-manual-of-systematic-bacteriology-and-determinative-bacteriology/

https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue

Week 4: Cell Structure

klich2807 — 2025-09-22 00:16:19 UTC

The structures found in the dengue virus include a viral RNA genome, which is surrounded by a nucleocapsid; an outer envelope; and envelope proteins along the outside of the virus. These proteins are E and M proteins (envelope and membrane proteins). The E and M proteins serve as protection to the virus, as well as regulation of entrance into host cells. Dengue is circular with a spiky and rough exterior, due to the E and M proteins. The diameter of dengue is typically about 50nm. Since dengue is classified as a virus, it is acellular. This virus exploits the RNA of host cells in order to replicate the viral genome and proteins.

https://www.bioexplorer.net/file/Virus-Structure-Wiki-696x460.jpg

https://www.nature.com/scitable/topicpage/dengue-viruses-22400925/#:~:text=The%20dengue%20virus%20is%20a%20roughly%20spherical%20structure,replicate%20the%20viral%20RNA%20genome%20and%20viral%20proteins.

Week 5: Metabolism

klich2807 — 2025-09-28 19:49:16 UTC

Dengue is classified as a single stranded RNA virus. Therefore, it does not have a specific metabolic system. It also does not fit into a category of heterotroph or autotroph. However, dengue can cause metabolic changes in the host in which it is present. Some of these changes can include modification to immune system regulation, changes in bile and uric acid levels, and altered amino acid metabolism.

https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue

https://virologyj.biomedcentral.com/articles/10.1186/s12985-025-02745-3

https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0006217

Week 6: Growth Requirements

klich2807 — 2025-10-06 00:44:34 UTC

Oxygen: Since dengue is a virus, it does not require oxygen but is also not classified as any aerobe or anaerobe.

Salt: Dengue is not a halophile or halotolerant. It thrives only in the host.

Temperature: The virus thrives in the host of a human body, classified as a mesophile.

pH: Dengue is a neutrophile, thriving in a pH level range of 6-7.8.

Best way to grow: Dengue grows best in the human host. Temperatures are classified in the mesophile range, and pH in the neutrophile range. Salt and oxygen concentrations do not impact the growth of dengue.

https://www.cdc.gov/dengue/index.html

https://www.who.int/news-room/questions-and-answers/item/dengue-and-severe-dengue

Week 7: Genome Analysis

klich2807 — 2025-10-12 22:12:14 UTC

The dengue virus has a single stranded RNA (ssRNA) genome. It is classified as positive-sense RNA, allowing it to be translated directly into proteins. Since dengue is a virus, it does not have plasmids or antibiotic resistance genes.

The dengue genome has been mapped and is about 10.7 kb long.

https://www.nature.com/scitable/topicpage/dengue-viruses-22400925/

https://jbiomedsci.biomedcentral.com/articles/10.1186/s12929-024-01030-9

https://academic.oup.com/bfg/article/16/4/217/2883391

Week 8: Virulence Factors

klich2807 — 2025-10-20 03:49:47 UTC

DENV-4 has antibiotic resistance genes against ciprofloxacin and difloxacin. However, dengue does not have anecessity to produce antibiotic resistance genes because it is a virus. This virus has no exoenzymes. Some of the immune evasions of dengue include modification of RNA and inhibiting antigen presentation. Dengue may have antigenic variation through genetic divergence, antigenic fitness, cross-neutralization, and evolutionary dynamics.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7528753/

https://www.mdpi.com/2673-5601/4/4/33

https://bedford.io/projects/dengue-antigenic-dynamics/

Week 9: Biochemical Tests

klich2807 — 2025-10-27 02:14:36 UTC

Dengue is a positive-stranded RNA virus with spherical virion particles and surface proteins. Since dengue is a virus, it does not properly react to tests such as phenol red, IMViC, catalase, and oxidase. However, it can be found with serological culture tests of blood, plasma, and urine. RT-PCR is the most commonly used method of determining the presence of the dengue virus.

https://jbiomedsci.biomedcentral.com/articles/10.1186/s12929-024-01030-9

https://iris.who.int/server/api/core/bitstreams/7f5d3370-9990-426d-a848-9225f3ecbc48/content

Week 10: Diagnostic Tests

klich2807 — 2025-11-03 01:57:46 UTC

Dengue virus can be detected with a few different methods. The main type of testing are nucleic acid amplification tests (NAAT), such as RT-PCR. Within the first week of infection, the NS1 antigen test is effective in determining the presence of the viral protein, NS1, that is located in the blood when infected with dengue. After the first week of infection, antibody tests such as IgM and IgG are useful in determining the presence of antibodies, indicating previous infection. A combination of IgM and NS1 testing can be used in the first week to provide a diagnosis as well. Thus, the ELISA test is effective in detecting the NS1 protein and IgM or IgG antibodies.

https://emedicine.medscape.com/article/215840-workup?form=fpf

https://news.mayocliniclabs.com/2020/01/06/dengue-virus-a-diagnostic-testing-update/#:~:text=The%20NS1%20antigen%20is%20also%20detectable%20during,5%20to%207%20days%20following%20symptom%20onset

https://www.cdc.gov/dengue/hcp/diagnosistesting/index.html#:~:text=A%20nucleic%20acid%20amplification%20test%20(NAAT)%20(e.g.%2C%20RT,does%20not%20rule%20out%20infection.

Week 11: Transmission of Dengue

klich2807 — 2025-11-03 22:14:21 UTC

Dengue is directly transmitted through mosquito bites of an infected mosquito within the Aedes genus. Indirect transmission may occur through blood transfusions, organ transplants, and to a fetus through the infected mother. The vectors of dengue include the mosquito species Aedes aegypti and Aedes albopictus. Since it is more common for dengue to be transmitted directly, there are no applicable fomites that contribute to the transmission of dengue.

https://www.dhs.wisconsin.gov/mosquito/dengue-about.htm#:~:text=Dengue%20is%20spread%20to%20humans,with%20dengue%20never%20develop%20symptoms.

https://www.cdc.gov/dengue/transmission/index.html

https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Dengue.aspx#:~:text=How%20do%20people%20get%20dengue,other%20people%20when%20it%20bites.

https://www.mayoclinic.org/diseases-conditions/dengue-fever/symptoms-causes/syc-20353078#:~:text=Subscribe!,bloodstream%20and%20causes%20an%20infection.

Week 12: Pathology and Immune Response

klich2807 — 2025-11-16 18:41:43 UTC

Signs and Symptoms: Some of the signs and symptoms presented by the dengue infection include headache pain behind the eyes, joint and muscle aches, high fever, nausea, vomiting, rash, and swollen lymph node glands.

Damage Caused by Dengue: The cellular damage that may be caused by dengue is endothelial cell damage, platelet activation, inflammation, and hemorrhagic symptoms.

Immune Response: The main immune response to the dengue virus is the production of antibodies. Therefore, the cells recruited to the infection are T cells, B cells, memory B cells, and antigen-presenting cells through a cell-mediated response.

Autoimmunity: Dengue does not cause any autoimmune diseases or responses.

https://www.cdc.gov/dengue/signs-symptoms/index.html

https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.810376/full

https://www.nature.com/scitable/topicpage/host-response-to-the-dengue-virus-22402106/#:~:text=To%20fight%20the%20infection%2C%20the%20immune%20system%20produces,antibodies%20and%20white%20blood%20cells%20remove%20the%20virus.

https://pmc.ncbi.nlm.nih.gov/articles/PMC9990932/

Week 13: Treatment

klich2807 — 2025-11-23 20:58:16 UTC

Unfortunately, there are no specific treatments for dengue virus; however, there are options to treat signs and symptoms rather than the virus itself. Over the counter pain relief and anti-inflammatory medications, like acetaminophen. Patients are instructed to avoid ibuprofen and aspirin since those medications can increase the risk of bleeding. Staying hydrated and resting are also great options for recovering from dengue virus. If signs and symptoms are drastic or continue to worsen, hospitalization may be necessary where medical professionals will monitor the patient and provide proper care through medication and hydration through IV.

https://www.healthdirect.gov.au/dengue-fever

https://www.health.nsw.gov.au/Infectious/factsheets/Pages/dengue.aspx

https://www.mayoclinic.org/diseases-conditions/dengue-fever/diagnosis-treatment/drc-20353084

Week 14: Epidemiology

klich2807 — 2025-11-25 22:33:06 UTC

The most recent outbreak of dengue began in 2024, where 13 million cases of infection from dengue were reported in South America, Central America, North America, and the Caribbean. This outbreak is classified as an epidemic, and was expected to escalate in the amount of patients infected in 2025. However, there has not been a dengue pandemic. Since the outbreak, the prevalence rate of dengue has incredibly decreased, especially in the United States in North America. There are currently 3,952 reported cases of dengue in the US, with no new cases since the beginning of November. For the mortality rate, there were approximately 12,000 deaths caused by dengue in 2024.

Dengue is a CDC notifiable disease.

https://www.cdc.gov/dengue/outbreaks/2024/index.html

https://www.pbs.org/newshour/health/what-you-need-to-know-about-the-latest-outbreak-of-dengue-fever

https://www.cdc.gov/dengue/data-research/facts-stats/current-data.html

https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue

Week 15: Case Study

klich2807 — 2025-12-08 00:55:28 UTC

Patient Details:

32 year old male
Admitted to hospital July 14, 2022
Weighed 56 kg
158 cm tall

Signs and Symptoms:

Pain in legs
Swelling on hands and lips
Fever of 102F
Nasal bleeding
Weakness
Elevated total leukocyte count
Positive Candida tropicalis blood culture

Treatment:

Ceftriaxone
Fluconazole 200mg
Paracetamol injection
Dimenhydrinate

Contracted:

Transmitted through zoonotic vehicle
Mosquito bite in Shirasgoan village

Outcome:

Improved patient conditions
Paralysis at the time of discharge
Continued pain in lower limbs
Edema on hands and feet
Reduced fever

https://ijcrt.org/papers/IJCRT2301184.pdf