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  • Immunize for Immunity

Tropical Diseases

Written by: Sasi Valiveti

There are many who wish to visit tropical destinations, perhaps for water sports in the river or cruising the jungle. Tropical destinations are renowned for their eco-tourism related activities, distinct culture, and exotic wildlife, however, tourists should consider the risks associated with the hot, humid climate, street food, activities, and lodging. Many have contracted and even passed away from diseases in these areas. Below are examples of common examples of tropical diseases that can be contracted from tropical destinations.


Dengue fever is an infectious disease caused by any of the four Dengue strains carried by mosquitoes. To infect a cell, the Dengue virus binds to the cell surface and subsequently enters the cell after becoming enveloped by the cell membrane in a pouch called an endosome. It then travels deeper into the cell and enters the fluid interior of the cell, where it produces its genetic material and replicates itself. Mild Dengue fever has symptoms that include high fever, muscle/joint pain, and rash. Mild Dengue fever can progress to Dengue hemorrhagic fever, in which individuals experience severe bleeding, shock, and death.

Zika Virus

The Zika virus is another infectious, mosquito borne disease transmitted primarily by Aedes mosquitoes, which bite during the day, peaking in the early morning and late afternoon. This type of mosquito also transmits Dengue fever, Chikungunya virus, and yellow fever. Zika can also be transmitted through sexual contact, blood/platelet transfusion, organ transplantation, and from mother to fetus during pregnancy. Most of the individuals infected with Zika do not appear to have any symptoms. Mild cases of Zika have symptoms including fever, rash, conjunctivitis, muscle/joint pain, malaise, and headache lasting from 2-7 days. It can also, however, trigger for various neurological conditions in older children and adults. During pregnancy, the Zika virus is the cause of microcephaly and other congenital abnormalities in a developing fetus and newborns. It can also result in pregnancy complications such as fetal loss, stillbirth, and premature birth.

Yellow Fever

In addition to the Dengue fever and the Zika virus disease, Yellow fever is another mosquito borne disease common in parts of South America and Africa. It is recommended that travelers get a vaccine when traveling to these areas. Symptoms of mild cases of Yellow fever include fever, headache, nausea, and vomiting. Yellow fever can become more severe, with symptoms progressing into heart, kidney, and liver problems and hemorrhaging. Up to 50% of individuals infected with the severe form of this disease will die. There is no specific treatment for this disease.


Rotavirus is an extremely contagious disease most prevalent in infants and children, in whom the disease is the most common cause of diarrhea. This disease is responsible for nearly 215,000 deaths annually around the world. This virus spreads through direct contact and contact with bodily fluids. It can be present in an individual’s stool for several days before symptoms are present.

The symptoms of Rotavirus include fever, nausea, vomiting, watery diarrhea, abdominal pain, and dehydration. These symptoms can become more severe, consisting of more frequent episodes of vomiting, black or blood-filled stool, high fever, lethargy, irritability, bowel movements, and severe dehydration.


Ebola virus is a very rare and deadly disease caused by a group of viruses prevalent in sub-Saharan Africa. This virus spreads through direct contact, contact with body fluids, and contaminated surfaces/objects. Ebola virus can only be spread from person to person if the infected person has developed symptoms. Primary symptoms of Ebola include fever, body aches, headache, abdominal pain, and fatigue. During later stages, red eyes, rash, and hiccups may develop. This disease is extremely deadly and recovery depends on a patient’s care and immune response. A similar disease is the Marburg virus, which usually has a lower mortality rate.

Lassa Fever

Lassa Fever is an animal-borne disease carried primarily by rats and is endemic to parts of West Africa, where the rats are distributed throughout the region.

For up to 80% of cases, this disease is undiagnosed as its mild symptoms, consisting of mild fever, malaise, and headache, are common symptoms. In some individuals, the disease may progress to its severe form with symptoms consisting of hemorrhaging from the gums, eyes, ears, nose, skin, etc., respiratory problems, frequent vomiting, facial swelling, chest, back, and abdominal pain, and shock. Death usually occurs for up to two weeks after severe symptoms manifest due to multiple organ failure. Approximately 20% of individuals die of the severe form of the disease.

Survivors of this disease may face severe complications. The most common of these complications include deafness, which is permanent and occurs for up to 1/3rd of individuals. Other complications are neurological, including encephalitis. This virus is especially dangerous for women in late-stage pregnancy, as it can lead to spontaneous abortion of the fetus. This disease has a 95% mortality rate for fetuses.


Cholera is a bacterial, diarrheal borne disease caused by infection of the bacteria Vibrio cholerae prevalent in areas with poor sanitation. This bacteria is transmitted through bodily fluids and waste. This disease is responsible for nearly 315,000 deaths annually and can kill within hours if left untreated.

Symptoms include severe watery diarrhea and abdominal pain, causing severe dehydration.

While symptoms of these diseases can be mild, they can progress rapidly into severe cases which can result in severe complications and death. While these are the more commonly known tropical diseases, there are many neglected diseases that are life-threatening and do not have proper forms of treatment. This is why it is important to take proper precautions depending on which tropical area you are visiting. You should take the appropriate vaccinations and travel with the appropriate medications when traveling to tropical regions. In this way, infections and outbreaks can be prevented and safety can be ensured.

Works Cited

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Ph.D., CRNP, Ed.). Medical News Today.


Cholera. (2019, January 17). World Health Organization.


Daley, J. (2019, April 12). A World War I soldier's cholera seemed odd. 100

years later, researchers have sequenced his bacteria's genome. Smart News.


Dengue fever. (n.d.). Mayo Clinic.


Dengue fever biology & transmission. (2016, June 24). National Institute of

Allergy and Infectious Diseases.


Ebola (Ebola virus disease). (n.d.). Centers for Disease Control and Prevention.

How Dengue virus infects cells. (2010, October 25). National Institutes of



Lampner, C., MSLIS. (2018, March 20). Chikungunya virus: What every rheumatologist should know. Rheumatology Advisor.


Lassa fever. (n.d.). Centers for Disease Control and Prevention.

Rotavirus. (n.d.). Mayo Clinic.


Transmission. (n.d.). Vital Record.


Yellow fever. (n.d.). Centers for Disease Control and Prevention.

Yellow fever. (n.d.). Mayo Clinic.


Zika virus. (2018, July 20). World Health Organization.


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