1. Introduction

The mosquitoes' ability of disease transmission is studied since the nineteenth century, although malaria has affected humanity for millennia. Oswaldo Cruz called it "Amazonian's elf," and in the 50th year, a new disease combat method became important worldwide, the medicated salt of Mario Pinotti. Since this, the efforts of the Oswaldo Cruz Foundation (Fiocruz) combated and prevented the diseases transmitted by mosquitoes in Brazil. Among these diseases, we can find malaria, dengue, Zika and chikungunya. Brazilian territory is an endemic area for their transmission, considering the tropical climate and the Brazilian population habits. In the last years, the country was affected by an outbreak caused by chikungunya virus and by the third arbovirus (Zika virus—ZIKV). These viruses were responsible for causing a large number of infections [1, 2].

## 1.1 Aedes aegypti

The first report about Aedes aegypti is dated from 1925 by Kirkpatrick, in Egypt [3]. Aedes aegypti is a small dark-colored mosquito with white stripes markings. Mosquito is considered domesticated animal as much as other animals, such as the pet dog or cat [3]. These mosquitoes can use natural locations or artificial containers with waters to lay their eggs, thus tree holes, plant axils and common household items that can accumulate rainwater, for example, are potential breeding sites, especially when these locations contain organic material. During their lifetime, the A. aegypti females are found around the houses and all day long they are capable of biting humans. Unlike most other mosquitoes, Aedes mosquitoes are active and bite only during the daytime, with peak activity during the early morning and in the evening before dusk. They are also capable of biting other animals, but without transmitting diseases to them. Thus, after feeding on human blood, they lay her eggs in the still water. These eggs are laid over a period of several days, and they are resistant to desiccation surviving for long periods of six or more months, until they have contact with water again, and the larvae are released [4, 5].

Dengue is a flaviviruses infection transmitted by mosquitoes of Aedes genus, mainly A. aegypti and A. albopictus. The dengue virus (DENV) comprises five distinct serotypes, and this disease is a fast emerging pandemic-prone viral consid-

The first epidemic of dengue hemorrhagic fever occurred in Manila, Philippines, between 1953 and 1954, followed by Bangkok, Thailand and Malaysia in 1958 and Singapore and Vietnam in 1960. Due to economic growth and consequent increase of post-World War II urbanization, the epidemic of dengue and hemorrhagic dengue spread in the 1970s to other areas of the world, starting in Southeast Asia [10]. In Brazil, since the 1980s, there is an intense virus circulation with epidemic

The World Health Organization (WHO) estimates 100 million symptomatic cases per year and 2.5 billion people are at risk of infection worldwide. There are no available vaccines and no effective treatment for dengue, which reinforces the need for strategies to prevent virus transmission by the main vector A. aegypti (Figure 1). ZIKV is also transmitted by Aedes aegypti, and it was first isolated from a rhesus macaque (Macaca mulatta) placed as sentinel during a study about yellow fever in the Zika Forest, Uganda, Africa in 1947 [15]. ZIKV had its first documented outbreak only in 2007 in Micronesia. Since then, the transmission area has spread to islands in the Pacific Ocean, especially during a great epidemic in Polynesia in October 2013. In 2015, some cases of humans infected by ZIKV were reported in Brazil, developing into an outbreak that spread throughout South America, the Caribbean islands and Central America. Originally adapted to a zoonotic cycle in Africa, ZIKV evolved into an urban cycle involving a human reservoir and domestic

Zika virus was first identified in Uganda in 1947. Before 2007, only sporadic human cases were reported from countries in Africa and Asia. In 2007, the first documented Zika virus disease outbreak was reported in the Federated States of Micronesia. In subsequent years, outbreaks of Zika virus disease were identified in countries in Southeast Asia and the Western Pacific. Zika virus was identified for the first time in the Western hemisphere in 2015, when large outbreaks were reported in Brazil. Since then, the virus spread throughout the Americas

Chronological spread of DENV (adapted from https://www.centralmosquitocontrol.com/resources/disease-inf

ered the major public health challenge worldwide [4, 13].

DOI: http://dx.doi.org/10.5772/intechopen.79780

Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges…

bursts affecting all the regions of the country [14].

mosquito vectors [16].

(Figure 2) [17].

Figure 1.

105

ormation/dengue).

In America regions, A. aegypti is the only epidemiological important species transmitting the dengue virus. This species is originated from Africa where it was domesticated and adapted to the environment created by man, becoming anthropophilic. In the seventeenth century, these mosquitoes started spreading all over the world, to Mediterranean in the eighteenth century, to tropical Asia in the nineteenth century and to Pacific Island in the end of the nineteenth century and beginning of the twentieth century. These adaptive characteristics allowed them to become abundant in many cities and easily carried to other areas by means of transport, which increased their vectorial competence, that is, their ability to become infected by a virus, to replicate it and transmit it. Although A. aegypti eradication took place in the Mediterranean in the 1950s and between 1950s and 1960s in most countries of the Americas, there was a reinfestation in most of the areas from which it had been previously eradicated. Nowadays, this vector is considered a cosmotropical species due to the increasing adaptive capacity of the A. aegypti [6–10].

In the past, Aedes albopictus has its origin in the Asian jungles, but in consequence of an intense tire trade, by sea, this vector came to the Americas in the 1980s, firstly to the USA and then, in Brazil and in others countries of the Central and South America, in Africa, Europe but either in some Pacific Island [6]. A. albopictus also lays their eggs in tree holes, but differently of A. aegypti, that mosquito has their habits outside the household and bites both animals and humans (anthropophilic and zoophilic diurnal habits). In Asia, A. albopictus is responsible for the transmission of epidemic outbreaks of classical and hemorrhagic dengue fever [11].

### 1.2 Arboviruses: dengue, Zika and chikungunya

Arboviruses (an acronym of ARthropod-BOrne virus) have caused much concern in public health worldwide. Arboviruses have been emerging in different parts of the world due to genetic changes in the virus, alteration of the host and vector population dynamics or because of anthropogenic environmental factors. These viruses' capacity for adaptation is notable, as well as the likelihood of their emergence and establishment in new geographic areas [12]. Here, we highlight three important viruses such as dengue virus (DENV), chikungunya virus (CHIKV), and, lately, Zika virus (ZIKV).

Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges… DOI: http://dx.doi.org/10.5772/intechopen.79780

Dengue is a flaviviruses infection transmitted by mosquitoes of Aedes genus, mainly A. aegypti and A. albopictus. The dengue virus (DENV) comprises five distinct serotypes, and this disease is a fast emerging pandemic-prone viral considered the major public health challenge worldwide [4, 13].

The first epidemic of dengue hemorrhagic fever occurred in Manila, Philippines, between 1953 and 1954, followed by Bangkok, Thailand and Malaysia in 1958 and Singapore and Vietnam in 1960. Due to economic growth and consequent increase of post-World War II urbanization, the epidemic of dengue and hemorrhagic dengue spread in the 1970s to other areas of the world, starting in Southeast Asia [10].

In Brazil, since the 1980s, there is an intense virus circulation with epidemic bursts affecting all the regions of the country [14].

The World Health Organization (WHO) estimates 100 million symptomatic cases per year and 2.5 billion people are at risk of infection worldwide. There are no available vaccines and no effective treatment for dengue, which reinforces the need for strategies to prevent virus transmission by the main vector A. aegypti (Figure 1).

ZIKV is also transmitted by Aedes aegypti, and it was first isolated from a rhesus macaque (Macaca mulatta) placed as sentinel during a study about yellow fever in the Zika Forest, Uganda, Africa in 1947 [15]. ZIKV had its first documented outbreak only in 2007 in Micronesia. Since then, the transmission area has spread to islands in the Pacific Ocean, especially during a great epidemic in Polynesia in October 2013. In 2015, some cases of humans infected by ZIKV were reported in Brazil, developing into an outbreak that spread throughout South America, the Caribbean islands and Central America. Originally adapted to a zoonotic cycle in Africa, ZIKV evolved into an urban cycle involving a human reservoir and domestic mosquito vectors [16].

Zika virus was first identified in Uganda in 1947. Before 2007, only sporadic human cases were reported from countries in Africa and Asia. In 2007, the first documented Zika virus disease outbreak was reported in the Federated States of Micronesia. In subsequent years, outbreaks of Zika virus disease were identified in countries in Southeast Asia and the Western Pacific. Zika virus was identified for the first time in the Western hemisphere in 2015, when large outbreaks were reported in Brazil. Since then, the virus spread throughout the Americas (Figure 2) [17].

#### Figure 1.

Chronological spread of DENV (adapted from https://www.centralmosquitocontrol.com/resources/disease-inf ormation/dengue).

1.1 Aedes aegypti

Malaria

released [4, 5].

A. aegypti [6–10].

fever [11].

104

lately, Zika virus (ZIKV).

1.2 Arboviruses: dengue, Zika and chikungunya

The first report about Aedes aegypti is dated from 1925 by Kirkpatrick, in Egypt [3]. Aedes aegypti is a small dark-colored mosquito with white stripes markings. Mosquito is considered domesticated animal as much as other animals, such as the pet dog or cat [3]. These mosquitoes can use natural locations or artificial containers with waters to lay their eggs, thus tree holes, plant axils and common household items that can accumulate rainwater, for example, are potential breeding sites, especially when these locations contain organic material. During their lifetime, the A. aegypti females are found around the houses and all day long

they are capable of biting humans. Unlike most other mosquitoes, Aedes

more months, until they have contact with water again, and the larvae are

domesticated and adapted to the environment created by man, becoming

mosquitoes are active and bite only during the daytime, with peak activity during the early morning and in the evening before dusk. They are also capable of biting other animals, but without transmitting diseases to them. Thus, after feeding on human blood, they lay her eggs in the still water. These eggs are laid over a period of several days, and they are resistant to desiccation surviving for long periods of six or

In America regions, A. aegypti is the only epidemiological important species transmitting the dengue virus. This species is originated from Africa where it was

anthropophilic. In the seventeenth century, these mosquitoes started spreading all over the world, to Mediterranean in the eighteenth century, to tropical Asia in the nineteenth century and to Pacific Island in the end of the nineteenth century and beginning of the twentieth century. These adaptive characteristics allowed them to become abundant in many cities and easily carried to other areas by means of transport, which increased their vectorial competence, that is, their ability to become infected by a virus, to replicate it and transmit it. Although A. aegypti eradication took place in the Mediterranean in the 1950s and between 1950s and 1960s in most countries of the Americas, there was a reinfestation in most of the areas from which it had been previously eradicated. Nowadays, this vector is considered a cosmotropical species due to the increasing adaptive capacity of the

In the past, Aedes albopictus has its origin in the Asian jungles, but in consequence of an intense tire trade, by sea, this vector came to the Americas in the 1980s, firstly to the USA and then, in Brazil and in others countries of the Central and South America, in Africa, Europe but either in some Pacific Island [6]. A. albopictus also lays their eggs in tree holes, but differently of A. aegypti, that mosquito has their habits outside the household and bites both animals and humans (anthropophilic and zoophilic diurnal habits). In Asia, A. albopictus is responsible for the transmission of epidemic outbreaks of classical and hemorrhagic dengue

Arboviruses (an acronym of ARthropod-BOrne virus) have caused much concern in public health worldwide. Arboviruses have been emerging in different parts of the world due to genetic changes in the virus, alteration of the host and vector population dynamics or because of anthropogenic environmental factors. These viruses' capacity for adaptation is notable, as well as the likelihood of their emergence and establishment in new geographic areas [12]. Here, we highlight three important viruses such as dengue virus (DENV), chikungunya virus (CHIKV), and,

decades, A. albopictus has spread from Asia to become established in areas of Africa,

There is no specific antiviral drug treatment for chikungunya. The treatment is directed primarily at relieving the symptoms, including the joint pain using antipyretics, optimal analgesics and fluids. There is also no commercial chikungunya

2. Clinical diagnosis and treatment for dengue, Zika and chikungunya

The greatest challenge is the differential clinical diagnosis between dengue, Zika and chikungunya. These three diseases have identical symptomatology and often the patient may present more than one disease at the same time or even having one of these diseases without the manifestation of symptoms. The clinical diagnosis can still occur after some days after the beginning of the infection, but mainly by

Dengue, Zika and chikungunya infection are diagnosed based on clinical, laboratory and epidemiological criteria. It is an important recognition and differentiation of the clinical symptoms and signs to make the correct diagnosis, start proper

Dengue is an exanthematic febrile disease, which is often accompanied by nausea, aches (especially frontal headache) and pains and responsible for high rates of

In dengue fever, the incubation period lasts for 4–10 days; after that, the disease

Zika fever and dengue are so similar, characterized by fever, exanthema, headache, conjunctivitis (nonpurulent), myalgia and arthralgia (notably small joints of

Unlike dengue, Zika presents low morbidity, but it is associated by diseases

(a neurological disorder that could lead to paralysis and death), myelitis and

Zika fever is very analogous to dengue, symptom manifests in period of 3–12 days and lasts for 4–7 days. It is estimated that in five infected patients, only

Chikungunya fever symptoms are sudden fever accompanied by headache, polyarthralgia (debilitating) or arthritis and maculopapular rash. The incubation period lasts for 2–12 days. Symptoms usually disappear in less than 2 weeks, but arthralgia may last even years. Severe chikungunya can manifest encephalitis, myocarditis, hepatitis and multiple organ failure that are fatal [32, 33] (Table 1). Diagnosis of dengue, Zika and chikungunya is primarily clinical. In regions of epidemic, dengue is primordial, look for warning symptoms and a complete blood count and transaminases to determinate the phase and severity of the disease. The

has three phases: febrile (lasts 2–7 days with no specific signs and symptoms); critical (last 24–48 h) and convalescence. The progression to severe dengue infec-

treatment and prevent the associated complications [26–28].

morbidity and mortality in countless endemic areas around the world.

tion (hemorrhagic fever) is variable and difficult to predict [29].

such as congenital microcephaly cases and Guillain-Barré syndrome

The first report for A. albopictus in the Americas occurred in Houston (the United States) in 1985. In Brazil, it was detected for the first time in 1986 in the states of Rio de Janeiro and Minas Gerais [21, 22]. A. albopictus was essentially a species wilderness that bred and fed on of the forests and adapted outside houses and inside houses in the various urban and suburban areas of their distribution, according to records made by Gomes and Pessoa [23, 24]. This mosquito species is

known as a secondary vector of chikungunya and dengue virus [25].

Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges…

Europe and the Americas [20].

DOI: http://dx.doi.org/10.5772/intechopen.79780

laboratorial diagnosis [26–28].

vaccine.

fever

hands and feet).

meningoencephalitis [30].

one develop them [31].

107

Figure 2.

Chronological spread of ZIKV (adapted from Ref. [18]).

Figure 3. Chronological spread of CHIKV.

Zika virus caused large outbreaks in previously unexposed populations, and from 2013 onward, outbreaks linked with neurological disorders including Guillain-Barré syndrome and congenital malformations, for reasons that are not yet known. The future transmission of Zika infection is likely to coincide with the global distribution of Aedes vectors [19].

A different arbovirus type, an alphavirus, is responsible for causing chikungunya. Differently than the other two diseases, dengue and Zika, chikungunya causes prolonged joint pain and persistent immune response.

Chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. It is an RNA virus that belongs to the alphavirus genus of the family Togaviridae. The name "chikungunya" derives from a word in the Kimakonde language, meaning "to become contorted" and describes the stooped appearance of sufferers with joint pain (arthralgia) (Figure 3) [20].

Both A. aegypti and A. albopictus have been implicated in large outbreaks of chikungunya, whereas A. aegypti is confined within the tropics and sub-tropics, A. albopictus also occurs in temperate and even cold temperate regions. In recent Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges… DOI: http://dx.doi.org/10.5772/intechopen.79780

decades, A. albopictus has spread from Asia to become established in areas of Africa, Europe and the Americas [20].

The first report for A. albopictus in the Americas occurred in Houston (the United States) in 1985. In Brazil, it was detected for the first time in 1986 in the states of Rio de Janeiro and Minas Gerais [21, 22]. A. albopictus was essentially a species wilderness that bred and fed on of the forests and adapted outside houses and inside houses in the various urban and suburban areas of their distribution, according to records made by Gomes and Pessoa [23, 24]. This mosquito species is known as a secondary vector of chikungunya and dengue virus [25].

There is no specific antiviral drug treatment for chikungunya. The treatment is directed primarily at relieving the symptoms, including the joint pain using antipyretics, optimal analgesics and fluids. There is also no commercial chikungunya vaccine.

### 2. Clinical diagnosis and treatment for dengue, Zika and chikungunya fever

The greatest challenge is the differential clinical diagnosis between dengue, Zika and chikungunya. These three diseases have identical symptomatology and often the patient may present more than one disease at the same time or even having one of these diseases without the manifestation of symptoms. The clinical diagnosis can still occur after some days after the beginning of the infection, but mainly by laboratorial diagnosis [26–28].

Dengue, Zika and chikungunya infection are diagnosed based on clinical, laboratory and epidemiological criteria. It is an important recognition and differentiation of the clinical symptoms and signs to make the correct diagnosis, start proper treatment and prevent the associated complications [26–28].

Dengue is an exanthematic febrile disease, which is often accompanied by nausea, aches (especially frontal headache) and pains and responsible for high rates of morbidity and mortality in countless endemic areas around the world.

In dengue fever, the incubation period lasts for 4–10 days; after that, the disease has three phases: febrile (lasts 2–7 days with no specific signs and symptoms); critical (last 24–48 h) and convalescence. The progression to severe dengue infection (hemorrhagic fever) is variable and difficult to predict [29].

Zika fever and dengue are so similar, characterized by fever, exanthema, headache, conjunctivitis (nonpurulent), myalgia and arthralgia (notably small joints of hands and feet).

Unlike dengue, Zika presents low morbidity, but it is associated by diseases such as congenital microcephaly cases and Guillain-Barré syndrome (a neurological disorder that could lead to paralysis and death), myelitis and meningoencephalitis [30].

Zika fever is very analogous to dengue, symptom manifests in period of 3–12 days and lasts for 4–7 days. It is estimated that in five infected patients, only one develop them [31].

Chikungunya fever symptoms are sudden fever accompanied by headache, polyarthralgia (debilitating) or arthritis and maculopapular rash. The incubation period lasts for 2–12 days. Symptoms usually disappear in less than 2 weeks, but arthralgia may last even years. Severe chikungunya can manifest encephalitis, myocarditis, hepatitis and multiple organ failure that are fatal [32, 33] (Table 1).

Diagnosis of dengue, Zika and chikungunya is primarily clinical. In regions of epidemic, dengue is primordial, look for warning symptoms and a complete blood count and transaminases to determinate the phase and severity of the disease. The

Zika virus caused large outbreaks in previously unexposed populations, and from 2013 onward, outbreaks linked with neurological disorders including Guillain-Barré syndrome and congenital malformations, for reasons that are not yet known. The future transmission of Zika infection is likely to coincide with the global

Chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. It is an RNA virus that belongs to the alphavirus genus of the family Togaviridae. The name "chikungunya" derives from a word in the Kimakonde language, meaning "to become contorted" and describes the stooped appearance of sufferers with joint pain (arthralgia) (Figure 3) [20]. Both A. aegypti and A. albopictus have been implicated in large outbreaks of chikungunya, whereas A. aegypti is confined within the tropics and sub-tropics, A. albopictus also occurs in temperate and even cold temperate regions. In recent

A different arbovirus type, an alphavirus, is responsible for causing chikungunya. Differently than the other two diseases, dengue and Zika, chikungunya causes prolonged joint pain and persistent immune response.

distribution of Aedes vectors [19].

Chronological spread of CHIKV.

Figure 2.

Malaria

Figure 3.

106

Chronological spread of ZIKV (adapted from Ref. [18]).

3. Epidemiology

world.

Figure 4.

Figure 5.

109

The Brazilian regions with the highest incidence and prevalence of these diseases (northeast and southeast region) present a favorable climate for the development of the Aedes aegypti (Figure 4) and the use of lighter clothes, which cover

Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges…

The number of suspected or confirmed dengue cases reported to the World Health Organization (WHO) is showed in Figure 5 as well its distribution in the

In 2015, the incidence of probable cases of dengue fever (number of cases/ 100,000 inhabitants), according to Brazilian geographic regions, shows that the

smaller areas of the body, favoring their exposure.

DOI: http://dx.doi.org/10.5772/intechopen.79780

Brazilian demographic density and latitude at geographic regions.

Average number of suspected or confirmed dengue cases reported to WHO, 2010–2016.


#### Table 1.

The main symptoms of dengue, Zika and chikungunya.

methods for establishing a laboratory diagnosis of these arboviruses are as follows: (1) detection of the virus for example, cell culture or viral RNA real-time detection; (2) antibody detection for example, IgM or IgG detection and (3) antigen/antibody combined detection for example, NS1 and IgM/IgG [27, 28].

These diseases are usually self-limiting with no need for hospitalization except warning signs are observed, especially severe dengue. There are no specific treatments available. Only symptomatic treatment with nonsalicylic analgesics and nonsteroid anti-inflammatories drugs are administrated when dengue infection is discovered. Patients should be advised to drink plenty of fluids to replace fluid lost from sweating, vomiting and others.

Aedes aegypti: The Main Enemy of Public Health in Brazil - Challenges… DOI: http://dx.doi.org/10.5772/intechopen.79780
