Dengue Disease

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Description

Dengue Disease

Country: Thailand

There are various disease outbreaks in Thailand. For instance, in the last month, there have been alerts of maladies such as melioidosis, malaria, dengue, rabies, rickettsia, influenza H1N1, H. influenza and HIV/AIDS. While these diseases occur in discordant magnitudes in Thailand, there are some such as malaria, cholera and dengue. I explored dengue disease in Thailand.

Article link: https://www.phuketgazette.net/lifestyle/top-ten-ways-avoid-dengue-fever

Article Summary

There have been approximately two hundred deaths and close to sixty-four thousand infections of dengue fever in Thailand in the last six months. According to this article, monsoons coming in the next month are expected to increase the number of people diagnosed with dengue disease. As such, the government will commence mosquito spraying and will impose fines on individuals who fail to remove mosquito breeding grounds from their properties. There are also other mechanisms or ways through which people can avoid getting dengue fever. For example, applying mosquito repellants, avoiding sweet smelling perfume or after-shave, showering without using scented lotions or soaps, sleeping under treated mosquito nets and burning mosquito coils are other ways through which people can avoid getting dengue disease.

Article source: Phuket Gazette

 

 

WHO/CDC SUMMARY

Definition and description of the dengue disease

Dengue is a leading cause of illness and death in the tropics and in the subtropics with as many as four hundred million getting infected yearly. Dengue is caused by any of the four closely related serotypes of dengue virus, that is, DENV 1. DENV 2, DENV 3 or DENV 4 (CDC, 2014). It is safe to assert that Dengue is a viral disease. Moreover, infection with one virus does not protect an individual against infection with the other viruses. In fact, sequential infections can occur whereby a person is infected by more than serotype of the dengue virus. In such a situation, the person is exposed to greater risk of getting dengue shock syndrome (DSS) and dengue hemorraghic fever (DHF).

Transmission

Dengue is transmitted between individuals by mosquitoes Aedes albopictus and Aedes aegypti. These mosquitoes are found all over the world. The symptoms of dengue normally begin four to seven days after a person is bitten by the virus-carrying mosquito and typically last between three and ten days. In order for the process of transmission to occur successfully, the mosquito must feed on an individual during a five-day period when large quantities of the virus are in his or her blood. This period normally commences a little prior to the person becoming symptomatic. However, people who never have significant symptoms can still infect mosquitoes. Once the virus has entered the blood stream of the mosquito, it will need an additional eight to twelve days incubation period before it can be transmitted by the mosquito to another individual.

In rare occasions, dengue can be transmitted through blood transfusions or organ transplants from infected donors. Moreover, according to the Centers for Disease Control and Prevention (CDC) (2014), there is evidence of transmission of dengue from an infected pregnant mother to her fetus. However, in most situations, mosquitoes are the ones responsible for transmission of dengue.

Symptoms

The primary symptoms of dengue include:

  • Presence of high fever and at least two of the following:
  • Severe eye pain, that is, behind the eyes
  • Muscle and bone pain
  • Mild bleeding manifestation, for example gum or nose bleed, easy bruising or petechie
  • Severe headache
  • Joint pain
  • Rash
  • Low white cell count (CDC, 2012).

It is vital to note that younger children and individuals experiencing their first dengue infection tend to have milder illness than older children and adults.

For individuals who have been infected, it is advisable to watch for warning signs such as temperature decreases three to seven days after the symptoms commenced. During this period, one is urged to report immediately to the nearest closest health care provider or emergency room should he or she notice any of the following signs:

  • Red patches or spots on the skin
  • Vomiting blood
  • Drowsiness or irritability
  • Difficulty breathing
  • Severe abdominal pain or persistent vomiting
  • Bleeding from gums and nose
  • Black and tarry stools or excrement
  • Pale, clammy or cold skin (CDC, 2012).

Dengue hemorrhagic fever (DHF) is characterized by a fever that lasts between two and seven days with signs and symptoms that are consistent with those of dengue fever. When the fever decreases, the warning signs may develop. This marks the onset of a twenty-four to forty-eight hour period when the smallest leucocytes become excessively permeable, enabling the fluid component to escape from the blood vessels into the pleural cavity and peritoneum. This may result in shock and failure of the circulatory system, as well as, death if there is no prompt and proper treatment (CDC, 2012).

Treatment

According to the Centers for Disease Control and Prevention (CDC) (2012), there is no specific medication that exists for treatment of dengue disease. People who reckon they have dengue and those diagnosed with dengue illness should utilize analgesics or pain relievers together with acetaminophen. They are advised to avoid taking medication that contains naproxen, aspirin, ibuprofen or aspirin containing drugs. Those infected should also rest and consume plenty of fluids to avoid dehydration while sleeping under treated mosquito nets or applying mosquito repellants to avoid mosquito bites while still febrile. They should also consult a physician.

Just as there is no specific medication for treating dengue, there is also no specific medication for Dengue hemorrhagic fever (DHF). In the event that a clinical diagnosis is made early, a health care provider can treat DHF efficiently using fluid replacement therapy (CDC, 2012). However, proper management of DHF requires hospitalization.

Prevention

Just as there is no specific medication to treat a dengue infection, there is no vaccine that prevents people from getting a dengue infection (CDC, 2012). This makes prevention the most vital step in avoiding a dengue infection, especially when one lives in an endemic area or traveling to an endemic area. Apart from avoiding mosquito bites, the best way of reducing mosquitoes is eradicating their breeding grounds such as artificial containers that hold open water in and around the homestead. An individual should also clean containers such as animal or pet watering containers, flower planter dishes, as well as, cover water storage barrels. It is also advisable to eliminate standing water indoors, for instance, in vases with fresh flowers (CDC, 2012).

Mosquitoes are known to bite people inside and outside their homes, both at night and during the day. Thus, people should protect themselves from mosquito bites by applying mosquito repellants on their skin while indoors and outside. People are also encouraged to wear pants and long sleeves for additional protection from mosquito bites. In the event that an individual in the house is infected with dengue, extra precautions must be taken to prevent mosquitoes from biting the patient and transmitting the disease by biting others. As such, people should sleep under mosquito nets and eliminate existing mosquitoes in their homes (CDC, 2012).

Interesting tidbit

The four serotypes of the dengue virus that is, DENV 1. DENV 2, DENV 3 and DENV 4 originated in monkeys and later jumped independently to humans in Southeast Asia and Africa between one hundred and eight hundred years ago. Dengue existed in a minor and geographically restricted state until mid-20th century. So how did the illness make its way to other continents? The coincidental transport of Aedes mosquito around the world in cargo following a disruption of the Second World War played a vital role in disseminating the virus. Its manifestation in humans was first documented in the 1950s during epidemics in Thailand and in the Philippines. However, it was not until 1981 that colossal outbreaks of DHF infection began to occur in Latin America and in the Caribbean where highly efficient Aedes control mechanisms had been implemented until early 1970s.

ARTICLES

Khetarpal, N., & Khanna, I. (2016). Dengue Fever: Causes, Complications, and Vaccine Strategies. Journal Of Immunology Research, 2016, 1-14. http://dx.doi.org/10.1155/2016/6803098

According to Khetarpal and Ira Khanna (2016), dengue may be a highly endemic infectious malady found mostly in the tropical nations, but is rapidly becoming a global burden. It is caused by any of the four serotypes of dengue virus and is transmitted from one individual to another through female Aedes mosquitoes. Nonetheless, the disease varies from mild fever to manifestations in the form of shock syndrome and dengue hemorrhagic fever. With advancement in technology and globalization, increase in unplanned urbanization and air travel has resulted in an increase in the rate of dengue infection and facilitated the dissemination of dengue disease to other nations and continents. Developing an effective virus has been a challenging task due to the existence of four dengue serotypes that are antigenically distinct and can trigger disease-enhancing antibody and cross-reactive responses against each other (Khetarpal and Ira Khanna, 2016). As revealed in this article, Brazil, Mexico and Philippines recently approved the Sanofi Pasteur’s chimeric live-attenuated dengue vaccine Dengvaxia for use in adults between nine and forty-five years of age. Notwithstanding, the virus registered poor if not minimal efficacy in dengue infected people during the third phase of its evaluation. This is because it only possessed yellow fever virus backbone and lacked the vital dengue T cell epitopes of the nonstructural region known for playing a pivotal role in providing protection against dengue. The authors recommend that an effective vaccine against dengue is that which does not permit production of antibodies as it will accommodate both naïve people and infants, thus, efforts in developing dengue vaccine should use this approach.

Chikaki, E., & Ishikawa, H. (2009). A dengue transmission model in Thailand considering sequential infections with all four serotypes. The Journal Of Infection In Developing Countries, 3(9). http://dx.doi.org/10.3855/jidc.616

Chikaki and Ishikawa (2009) reiterate the fact that dengue fever or dengue hemorrhagic fever is prevalent in Thailand where all serotypes can be found and the dominant serotype has altered its structure irregularly. Despite the fact that all principal infections of dengue are asymptomatic or occur with slight symptoms, there is limited information about the infectiousness of dengue fever (Chikaki and Ishikawa, 2009). This research conducted by the two authors employed a mathematical model of the transmission for dengue virus to cover and evaluate the possibility of sequential infections with all four discordant serotypes. The mathematical model was combined with the seasonal population dynamics of primary vectors of dengue virus in Thailand, that is, Aedes aegypti. The research also incorporated the contributions of inapparent cases in antibody-dependent enhancement and in the transmission to mosquito vectors and examined they hypothesis of “unnatural” infection whereby an individual obtains immunity by infection during a cross-immunity period via model simulations. Chikaki and Ishikawa (2009) found that the prevalence of dengue infection could be immediately stamped out or eradicated after a severe outbreak of the disease of inapparent cases had no infectiousness. Based on their research, the authors came to the conclusion that the hypothesis that inapparent cases had no infectiousness was not in agreement or relevant to the actual situation in Thailand. Moreover, the result of the simulation espoused the “unnatural” infection route as being capable of influencing epidemics of dengue. This article can be helpful in analyzing different hypotheses on the process of transmitting dengue disease. Moreover, careful research is necessary prior to planning of preventive measures against dengue including vector control since improper vector control may fortify the seriousness of future dengue epidemics.

Rodríguez-Barraquer, I., Buathong, R., Iamsirithaworn, S., Nisalak, A., Lessler, J., & Jarman, R. et al. (2013). Revisiting Rayong: Shifting Seroprofiles of Dengue in Thailand and Their Implications for Transmission and Control. American Journal Of Epidemiology, 179(3), 353-360. http://dx.doi.org/10.1093/aje/kwt256

As revealed in this article, dengue disease has been a critical public health problem in Thailand over the past fifty years. According to Rodríguez-Barraquer et al. (2014), dengue has conventionally caused substantial mortality and morbidity among children less than fifteen years of age in Southern Asia. Over the last two decades alone, a considerable rise in the mean ages of cases has been reported and once children-oriented disease now causes significant burden among the adult population. The authors conducted an age-stratified serological study among school children in the Mueang Rayong district of Thailand in 2010 where basic reproductive numbers of dengue and serotype-specific forces of infection were estimated for periods between 1969 and 1980 and 1993 and 2010. The results of the study revealed that despite a critical increase in the age at exposure and decrease in serotype-specific forces of infection from 0.038 to 0.019 annually, the basic reproductive numbers of dengue changed only by 0.1 from 3.3 to 3.2 (Rodríguez-Barraquer et al., 2014). Moreover, significant heterogeneity was evident across schools and sub-districts, with the basic reproductive numbers of dengue ranging between 1.7 and 6.8 (Rodríguez-Barraquer et al., 2014). The findings of this study a build on the concept that the observed age shift or change may be a consequence of the demographic change in Thailand and highlight the relevance of contemplating alterations in demography as drivers of change in age distribution of infectious maladies such as dengue. If demographic transition is a key driving force behind the observed alterations in the epidemiology of dengue in Southeast Asia and Thailand, it is likely that dengue will never be a disease that is exclusive to children only. Thus, control programs, epidemiological surveillance and management of dengue will need to expand their focus on detection, treatment and prevention of dengue to include both adults and children.

SUMMARY OF MY UNDERSTANDING OF DENGUE DISEASE

I have learned that dengue is viral disease that is caused by any of the four closely related dengue viruses, that is, DENV 1. DENV 2, DENV 3 or DENV 4. Getting infected with one of the four serotypes of the dengue virus does not exempt from being infected with another serotype. In fact, sequential infections can occur whereby a person is infected by more than serotype of the dengue virus. More severe forms of dengue disease occur in the form of dengue shock syndrome (DSS) and dengue hemorraghic fever (DHF). Given that manifestation in humans was first documented in the 1950s during epidemics in Thailand and in the Philippines, the occurrence of dengue in Thailand is important to consider when evaluating dengue illness. Dengue is transmitted between individuals by mosquitoes Aedes albopictus and Aedes aegypti. Its primary symptoms include severe headache, joint pain, rash, high fever, severe pain behind the eyes, muscle and bone pain and mild bleeding. It is vital to note that there is no specific medication for treating a dengue infection and no vaccine available for preventing people against dengue.

Brazil, Mexico and Philippines recently approved the Sanofi Pasteur’s chimeric live-attenuated dengue vaccine Dengvaxia for use in adults between nine and forty-five years of age. Notwithstanding, the virus registered poor if no minimal efficacy in dengue infected people during the third phase of its evaluation. As such, an effective vaccine against dengue is that which does not permit production of antibodies as it will include naïve people and infants, thus, efforts in developing dengue vaccine should use this approach. I also learned that while dengue disease was predominantly found in children, more and more cases of dengue infection are reportedly being found in adults. Thus, epidemiological surveillance, control programs and management of dengue should expand their focus on detection, treatment and prevention of dengue to include both adults and children.

 

Works Cited

CDC. (2012). Prevention | Dengue | CDC. Cdc.gov. Retrieved 28 February 2018, from https://www.cdc.gov/dengue/prevention/index.html

CDC. (2012). Symptoms and What To Do If You Think You Have Dengue | Dengue | CDC. Cdc.gov. Retrieved 28 February 2018, from https://www.cdc.gov/dengue/symptoms/index.html

CDC. (2014). Epidemiology | Dengue | CDC. Cdc.gov. Retrieved 28 February 2018, from https://www.cdc.gov/dengue/epidemiology/index.html

Chikaki, E., & Ishikawa, H. (2009). A dengue transmission model in Thailand considering sequential infections with all four serotypes. The Journal Of Infection In Developing Countries, 3(9). http://dx.doi.org/10.3855/jidc.616

Khetarpal, N., & Khanna, I. (2016). Dengue Fever: Causes, Complications, and Vaccine Strategies. Journal Of Immunology Research, 2016, 1-14. http://dx.doi.org/10.1155/2016/6803098

Newton, T. (2018). Top ten ways to avoid Dengue Fever | Phuket Gazette. Phuket Gazette. Retrieved 28 February 2018, from https://www.phuketgazette.net/lifestyle/top-ten-ways-avoid-dengue-fever

Rodríguez-Barraquer, I., Buathong, R., Iamsirithaworn, S., Nisalak, A., Lessler, J., & Jarman, R. et al. (2013). Revisiting Rayong: Shifting Seroprofiles of Dengue in Thailand and Their Implications for Transmission and Control. American Journal Of Epidemiology, 179(3), 353-360. http://dx.doi.org/10.1093/aje/kwt256