Analysis of Diseases
Overview
Chikungunya (CHIK) refers to a re-emerging arboviral disease transmitted by the mosquitos Aedes aegypty and Aedes albopictus (Pialoux 318). The virus belongs to the genus Alphavirus and family Togaviridae. The word chikungunya derives from Makonde language (spoken in Tanzania and northern Mozambique), where it means “to walk bent over” (Halstead 557). This name refers to the main feature of both chronic and acute phase of the disease a change in posture causes by the arthritis and arthralgia (Charrel, Lamballerie and Raoult 769).
History
The disease gained its name after the outbreak in Tanganyika, the modern Tanzania in 1952. However, the evidence of chikungunya pandemic was traced in the late 18th century in Egypt, Africa, Arabia, India and South East Asia (Halstead 558). In 1823 it was found in Zanzibar. Later, in 1827, it appeared in the Caribbean and was further spread to the South and North America (557). The first time chikungunya was reported in 1827-1828 on the Caribbean islands and as was described as “an arthritic fever with cutaneous exanthema” (557). In Zanzibar where an onset occurred in 1870 the disease was known as kidinga pepo (558). In 1828 was virus was found on the premises of New Orleans, Louisiana in the USA. It was explained by the transfer of slaves from Cuba (558). In 1964 the virus was found in India. During 2005-2006 the outbreak of chikungunya was observed on Reunion Island, where 265, 000 cases of infection were reported (Charrel, Lamballerie and Raoult 769). Later the disease was observed in France and Italy (Halstead 558). The virus was previously mistakenly confused with the dengue fever however recently the diseases were distinguished by the “suddenness of the onset and the nature and duration of the after-pain” (558).
Transmission, Symptoms, Treatment and Distribution
The chikungunya is transmitted by the bites infected mosquitos Aedes aegypty and Aedes albopictus from human to human. Usually, mosquitos are more actively bite in the early morning and the late afternoon (WHO). The silent incubation period after the bite lasts for 2-4 days. Then infected people experience myalgia, headache, back pain, arthralgia, and headache. Also, skin involvement takes place in 40-50% cases. For example, hemorrhagic fever was reported in Thailand. The symptoms generally resolve in approximately 10 days, except of the stiffness. The death is reported to be non-threatening to the life (Pialoux 322). According to the World Health Organization, most patients usually recover fully. However, there are occasions of eye, heart, gastrointestinal complications and contributions to death in the older people. There is only symptomatic treatment for the virus and it is based on the analgesics and anti-inflammatory drugs (Pialoux 325). Though previously the chikungunya could be observed only in African and Asia, its distribution broadened with the distribution of the mosquito Aedes albopictus around the world. Thus it is important to control the population and migration of these species.
Impact (health care, economic, social)
Several studies prove the significant health care, economic and social impact of the chikungunya on the countries where the epidemic was registered. Soumahoro et al. who examined the CHIK+ subjects reported that these individuals had more disabilities. However, no increase in medical consumption was noticed. Therefore, the impact as characterized as moderate on Reunion Island. In Taiwan, due to the highly infectious status of the disease, absence of the effective treatment and threat to the tourism industry, the virus also has moderate social impact on the country (Lo et al. 180). In India, where socioeconomic impact was researched, the evidence of greater influence of the chikungunya on the low income families was found (Kumar 150).
Status in the Future
The chikungunya virus already has the global status as it can be found in Asia, Africa, North and South America and recently reached Europe. In the future, the case of chikungunya will take place more often as the air and sea trade and tourism removed the barriers for its distribution.
Leishmaniasis
Overview
Leishmaniasis is defined a group of the infectious diseases caused by protozoan parasites which belong to the genus Leishmania. The parasites can be found in nature in the animal reservoirs and transmitted to humans by the bite of the female sandflies (Azevedo Cardoso et al. 279). Leishmaniasis is one of the neglected tropical diseases (Alvar 2). Though it causes the 9th largest disease burden among individual contagious diseases, its acknowledgment can be a problem because the disease is spread in the remote regions (1-2). Leishmaniasis diseases are divided into cutaneous, mucosal and visceral according to its clinical symptoms: ulcers on skin, destructions caused by mucus, and visceral infection or kala azar (Murray et al. 1561). Kala azar means “black fever” in Hindi because this kind of the disease is accompanied with the darkening of the skin (Murray et al. 1570).
History
The disease has been historically divided into the Old World and New World leishmaniasis. The first group refers to the disease found in the basin of Mediterranean Sea, African continent and the Middle East. The term “New World” defines the infection spread in Mexico, Central and South America (David and Craft 492). Leishmaniasis has a long history of observations. The traces of the disease have been found in ancient pictures, statues and mummies (Azevedo Cardoso et al. 282). Different images of skin deformities were found on the premises of Ecuador and Peru are dated from 1st century AD. Documents of the 15th and 16th centuries from the times of the Spanish colonization of Americas also prove the existence of the disease in tropical and subtropical regions (283). In Brazil leishmaniasis was first mentioned in Political-Geographical Religious Pastoral in 1827 while describing the journey of Don Hipólito Sánchez de Fayas y Quiros. Cunningham observed the parasite in India in 1885. Leishman and Donovan examined the same intracellular parasite as well. Further, the different kinds of Leishmania were observed by Lindenberg and Gaspar Vianna (283). Nowadays, over 350 million of people live in the areas of active transmission of parasites (David and Craft 491).
Transmission, Symptoms, Treatment and Distribution
It is reported that annually 1.5-2 million of children and adults get the symptomatic disease (visceral 0.5 million and cutaneous 1-1.5 million). Moreover, leishmanisis is associated with 2.4 million of disability-adjusted life years and around 70 000 deaths per year (Murray et al. 1562). The fatality rate of the disease is about 10%. The cutaneous form of the disease is mostly observed in Afghanistan, Pakistan, Syria, Saudi Arabia, Iran, Brazil and Peru. Visceral leishmaniasis is usually reported in India, Bangladesh, Nepal, Sudan and Brazil (1562). The disease is transmitted by the bites of female sandflies in the early morning or late afternoon. 70 out of 100 sandflies known at the moment are able to transmit the parasites. In different regions different parasites cause the leishmaniasis: Leishmania chagasi, L. infantum, L (Vianna) braziliensis in South America, L. Mexicana in Latin America, L tropica in the western parts of Asia, and L donovani in east Africa (1562). According to the World Health organization the disease is characterized with the following symptoms: fever, the loss of weight, anaemia, enlargement of the spleen and liver for kala azar. The disease is fatal without treatment in 95%. Cutaneous leishmaneasis results in skin ulcers and can cause scars and even disability cases. Mucocutaneous leishmaneasis leads to destruction of mucous membranes of nose, mouth and throat (WHO). There are different variants of the leshmaneasis treatment. The most popular are amphotericin, miltefosine, pentamidine and paromomycin. These drugs are used for different kinds of parasites. Therefore, their application depends on the endemic regions (Azevedo Cardoso et al. 284).
Impact (health care, social, economic)
The disease has the significant impact. It is widely recognized as a major health problem because of its complexity, rather high mortality rate, high incidence and treatment resistance (285). Besides, the social impact of the disease is strengthened by the cases of Leishmania-HIVcoinfection. It is reported that from the socioeconomic perspective, poverty increases the risk and impact of the infection. Besides, the healing effect is usually decreased because of bad nutrition in the regions where leshmaneasis is common (WHO).
Status in the Future
In the future the disease can cause serious problems not only in the developing countries but also in the United States and developed European states. The changes in environment and climate causes the wider spreading the parasites. On the other hand, there are several promising results for different kinds of novel drugs developed recently (Azevedo Cardoso et al. 286).
Malaria
Overview
Malaria is a contagious disease caused by the protozoan parasites that belong to genus Plasmodium. The infection is transmitted with the help of female mosquitos of Anopheles species (Cox 1). The name of the disease is derived from the Italian word malaria and literally means “bad air” as the spreading of the infection was associated with the swampy areas (Tuteja 4670). Malaria can be observed in a large number of countries though it more often occurs in tropical and subtropical climatic zones. Over 40% of the world population lives at risk of contracting the infection. The reports by the World Health Organization demonstrate between 350 and 500 million cases of malaria in 2004 (4670). The infection is defined as life-threatening.
History
Malaria is an ancient infection. There is evidence that the case of the disease was reported in the Chinese document written more than 2,000 years BC. Mesopotamian tablets, Egyptian papyri as well as Hindu texts of different epochs contain the information about this illness. Both ancient physician Hippocrates and early Greek poet Homer referred to the fever and enlarged spleens of citizens living near the swamps. Therefore, it was strongly believed that the air of the marshy areas should be blamed for the malaria transmission. However, the discovery of bacteria by Leeuwenhoek together with experiments by Pasteur and Koch inspired scientists to find out the reason of the ancient infection. The parasites were found in 1880 by Laveran. The human malaria vector was observed in 1897 by Grassi and his colleagues in Italy. Other important discovery belongs to Shortt and Garnham, who proved the development of Plasmodia in liver before appearance in the blood (Cox 1).
Transmission, Symptoms, Treatment and Distribution
Malaria is transmitted by the bite of the female Anopheles mosquito. There are around 400 species of these mosquitos, and 60 of them can cause the infection. However, there are 30 of them which are gained more importance. Malaria itself is the result of the activity of single-celled organisms from the genus Plasmodium. It is discovered more than 100 species and they are responsible for the diseases among reptiles, birds and mammals. Only four of them can naturally infect human beings. They are: Plasmodium vivax, P. falciparum, P. malariae and P. ovale. The classification of the parasites is related to their geographical distribution. Thus, P. falciparum is the agent of the potentially fatal form of malaria and the cause of death for the African young children. P. ovale is restricted to the West Africa. The most common parasite of malaria are P. malariae and P. vivax. They transmit the disease but rarely cause death (Tuteja 4671). The symptoms of the infection include chills, fever, headache and vomiting. The first symptoms can be hard to recognize. There are cases of anaemia, respiratory distress and cerebral malaria among children. The infection by P. falciparum is likely fatal if not treated within the first 24 hours (WHO). According to the last data from the World Health Organization, 3.2 billion of people are at risk of malaria as of 2015. The infection is distributed in sub-Saharan Africa, Middle East, Asia and Latin America. All in all, 95 countries are recorded in the list where malaria is transmitted (WHO). On the other hand, the disease is curable under the conditions of proper treatment. The first medicine used to cure the infection was based on the quinine from the Andes (fansidar and chloroquine). Nowadays, artemisinin obtained from Artemisia annua is widely used in the treatment (Tuteja 4674).
Impact (health care, social, economic)
Malaria has a huge economic and social impact in the countries where it can be transmitted. It is estimate that the disease results in the losses of more than $12 million annually for Africa. Moreover, it causes the death of 25% of children under the age of five and hampers the further economic development of the African countries (4670). These numbers also affects the continent from the social perspective. Malaria is closely related to the poverty. In the developed areas with temperate climate such as Western Europe and the USA the illness is almost eliminated.
Status in the Future
Though malaria can be cured within the first 24 hours after symptoms are revealed, it is still belongs to one of the major issues on the Earth. First of all, the disease is not always easily recnogized. Then malaria can be contracted more than once within the life. Finally, it is resistant to the treatment. Therefore, in the future the disease will remain the major problem and cause for death among children and adults in the African countries.
Dengue Fever
Overview
Dengue fever is an acute syndrome which results from arthropod-borne viruses (Halstead 1). The virus has 4 serotypes and all of them are members of the flaviviridae family and genus flavivirus (Bäck and Lundkvist). The virus is transmitted with the help of mosquitos Aedes aegypti and Aedes albopictus (Raheel et al. 239).
History
According to the historical information, the fever comes from Africa and appeared as a human disease 500 or 600 years ago. The dengue was first isolated and detected during the World War II. However, the dengue-like infection is mentioned in the old Chinese manuscripts dated back to 992. Besides, it is described in the West Indies in the 17th century (239). According to Halstead, the outbreaks of dengue fever were reported on all continents excluding Antarctica. The 18th and 19th were characterized with the epidemics on the recently colonized territories (3). Benjamin Rush was the first who provided details about the dengue shock syndrome, the form of the fever which can cause death or at least serious consequences to the health of an individual when the outbreak took place in Philadelphia (Raheel et al. 239). Bancroft discovered the role of Aedes aegypti in the spread of dengue. However, the virus was first cultured and isolated only in 1943-44.
Transmission, Symptoms, Treatment and Distribution
The dengue virus transmission depends on the location of two kinds of mosquitos Aedes aegypti and Aedes albopictus. The distribution of the infection reflects the location of mosquitos. Therefore, the control over their population can be considered an effective measure of dengue fever prevention. The density of the insects and the incidence of infection rise during the wet season. The symptoms of the dengue are biphasic fever, arthralgia or myalgia, rash, lymphadenopathy and leukopenia. The severe form of the virus disease is accompanied with abnormal hemostasis and can lead to the protein-losing shock syndrome (Halstead 1). The outbreaks of the disease took place in different parts of the world including the Caribbean islands, China, Kampuchea, Philippines, Nigeria, Mozambique and central and South America (3). Unfortunately, there are no effective vaccines against dengue fever at the moment. The disease is cured with the help of supportive care of bed rest and analgesics. The control of the mosquitos’ density remains the best prevention method (Bäck and Lundkvist).
Impact (health care, social, economic)
The recent researches prove that dengue fever gains more and more significant socioeconomic impact in the world. Previously, the problem was considered minor because of the low fatal rate and infrequent outbreaks. Despite the disease was limited to a few countries of Southeast Asia after the World War II, the virus accelerated recently and the infection became globally spread. Gubler mentions that in 2012 the impact of dengue has become more important than of malaria in terms of morbidity and economic perspective. He reports about 3.6 million people living in the risk zones as well as about 230 million incidences, 2 million severe disease cases and 21,000 deaths (743).
Status on the Future
The rising statistic data regarding the dengue fever indicates that the climate changes and globalization led to the global spread of the disease as well. In case no prevention measures are taken, the incidences of dengue fever can be expected higher than of malaria and cause more severe problems for the world as hardly any successful treatment have been developed as of nowadays.
Comparison of diseases’ impacts
The comparison of the impacts of the 4 above mentioned diseases indicates that different infections should be chosen as those having the greatest impact for individual and society. As for the latter, malaria seems to be the most significant among others. First of all, it is classified as a life –threatening disease according to the World Health Organization. This means that the incidence of the infection can cause severe complications and death. In 2015 it was reported that there were 214 million cases of malaria and 438, 000 deaths caused by the disease. Though mortality rate keeps decreasing from year to year, it is still rather high. Moreover, the infection caused by Plasmodium falciparum is fatal if not treated within the first 24 hours. Moreover, nearly half of the world population is at risk of contraction. In comparison dengue virus which can in some case lead to the fatal results does not have such a broad area of distribution. Another reason why malaria should be considered the most undesirable for the society is its economic burden. It is reported that the prevention and struggle with the malaria cases results in losses of more than $12 million annually for the African continent. Such losses are the serious threat for the economy. Moreover, the cases of the infection result in the losses for tourism, business. The high mortality level among children has a significant social impact. Dengue fever also has the great impact but its area of distribution is lower. Gubler, however, suggests that the situation with the dengue fever is going worse. On the other hand, the advances of pharmacology can finally result in the discovery or synthesis of the vaccine against the fever and other symptoms of the virus. Therefore, malaria remains the greatest burden for economy as well as it has the most significant social impact.
The consequences of leishmaniasis and chikungunya would be more harmful for the individual. Both these diseases affect the physical appearance of the person. Cutaneous leishmaniasis leaves ulcers on the skin which later result in scars. One of the consequences of chikungunya is the change in the posture and arthritis. The ability to live a joyful life will be significantly influenced by the after-effects of both diseases. Furthermore, the problems with bones can cause the ability of a person to enjoy the physical activities as well as hamper the opportunities of getting the job. Therefore, the chikungunya is considered to be more harmful for the individual.
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