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Mosquitoes: a danger to global health

According to the World Health Organization, there are approximately 212 million cases of malaria estimated in the world in 2015, 70 percent of which among children less than five.

In addition to malaria, mosquitoes are carriers of other dangerous diseases with over 500 million annual cases.

In order to fight this problem, the revolutionary TRILED technology is now alongside the already existing ones. It is suitable for any kind of environment: yellow light besides creating a bright and welcoming environment is an effective repellent: laboratory tested, unique and incredibly useful against the annoying and dangerous insects.

MALARIA

According to the World Health Organization data, approximately 212 million cases of worldwide malaria are estimated in 2015 and about 429,000 deaths, of which 70% are among children under the age of five (292,000 in the African Region ). Most cases were recorded in the African Region (90%), followed by Southeast Asia (7%) and the Eastern Mediterranean Region (2%).

Data show that incidence rates (in both cases -21%) and mortality (respectively -29% and -31% respectively) decreased between 2010 and 2015, both globally and in the African Region. A clear improvement in mortality data was recorded in the Western Pacific Region (-46%), the Americas Region (-37%) and the Eastern Mediterranean Region (-6%). Regarding the European Region, no indigenous malaria has been reported in 2015 (the last case was recorded in Tajikistan in July 2014).

Between 2010 and 2015, the mortality rate of malaria among children under the age of five is generally reduced, estimated at around 35%. However, it should be noted that in this age group malaria remains one of the most dangerous diseases, still to date is the cause of a child's death every two minutes.

Pathogens and their vectors

Protozoal etiologic agents of human malaria are 4, all belonging to the genus Plasmodim: Plasmodium falciparum, agent of the so called terzana malignant, the most severe form that can lead to death, P. vivax and P. oval, agents of two shapes benign, and P. malariae, quartan agent. A fifth plasmodio, P. knowlesy, which has some primates as a reservoir, can rarely cause even a benign quartan form in humans.

Malaria contracts after the female sting of one of about 60 different species of mosquito belonging to the Anopheles only genus. Among the most important species we find An. gambiae (main carrier in Africa) and An. stephensi (the main carrier in Asia) after this was infected with blood from a malarial subject. Before the Anofele becomes infectious, the plasmodium must undergo a development cycle within the mosquito itself, which may last for several days to a few weeks, depending on the plasmodial species and above all the ambient temperature.

Inside the human host, the parasite (endocellular) changes through various stages of development and succeeds in elusing immune system defenses, locating first in the liver, invading hepatocytes and amplifying by schizogony, invading globulins red, where it reproduces again for schizogonia, giving rise to new generations of parasites every 3 (third) or 4 (quartana) days. After some developmental cycles, Plasmodium produces sexuated shapes (gametocytes), Plasmodium is again ready to infect a new mosquito.

Chikungunya fever, Dengue and Zika virus are viral acute viruses transmitted by mosquitoes, belonging to the genus Aedes, in particular from the species Aedes aegypti and Aedes albopictus (mosquito tiger). In epidemics, the only host to the virus is man.

DENGUE

According to the World Health Organization, dengue causes around 50 million cases each year worldwide, most of which occur on the continents of the south of the world, particularly in tropical and subtropical areas. In the United States, CDCs record about 100-200 cases of imported dengue every year from people who have traveled abroad in areas where the virus mosquito virus is widespread. According to Cdc, between 1977 and 1994, nearly 2300 cases of illness were imported into the United States. However, the figure is probably underestimated because in many cases the disease is not identified by the treating physicians.

The prevalence of the disease, according to the Oms, has dramatically increased in recent years and dengue is endemic today in more than 100 countries in the southern parts of the world. Before 1970, only nine countries had reported cases of dengue and dengue bleeding. Today, the WHO estimates that two-fifths of the world's population are at risk of dengue. In 2001 there were more than 600,000 cases registered only in the American continent, of which over 15,000 were cases of haemorrhagic dengue. A number that is double the number of cases recorded in the same area in 1995. In addition, in recent years, dengue has been increasingly manifested by violent epidemics such as that in Brazil in 2001, where more than 390,000 people became ill, including 670 of dengue bleeds.

The most affected countries

In recent decades, dengue has set itself as an emergency of public health, especially in central and southern America. Since 2003, 24 countries in this region reported confirmed cases of haemorrhagic dengue fever.

In June 2007, Brazil reported more than 245,000 cases of dengue fever, against 300,000 registered in 2006 and around 800,000 in 2002, while Paraguay reported more than 25,000 cases in 2007, 52 of which were hemorrhagic dengue fever and 13 dead.

In addition, dengue fever is widespread in Southeast Asia: every year, in fact, 8 of the 11 countries in this region report to WHO cases of illness. According to the WHO, in 2005, 179,312 cases were reported in the region, more than half of them in Indonesia. The region has an average of more than 100,000 cases each year since 1985, although dengue fever is universally considered a under-reported disease.

After a decade long absence, the virus re-emerged in Asia in the 1980s, with dengue haemorrhagic epidemics in Sri Lanka, India, Maldives, China and Taiwan. The first epidemic registered in China is in 1985 and in Pakistan in 1994. In Singapore, after effective prevention for over 20 years, dengue has returned with hemorrhagic epidemics between 1990 and 1994. In other parts of Asia, where it is endemic, the epidemics of recent years have been progressively more serious. Even in Africa, despite poor monitoring, there have been more and more cases since the 1980s, especially in eastern areas, such as Kenya (1982 epidemic), Mozambique (1985), Djibouti (1991-92) and in Somalia (1982 and 1993).

It is in the American continent that dengue is becoming a major public health problem. The presence of the mosquito Aedes aegypti, a vector of the disease, had been drastically reduced by a program of control of the Panamanian organization of the WHO in the 1950s and 1960s, aimed at eradicating yellow fever, the virus being transmitted from the same mosquito. The program was discontinued in the 1970s in the United States, and progressively in other parts of the United States, with the result that the mosquito has reappeared and has also started to populate areas where it had not previously been present, as the epidemiological data of the WHO show. In addition, in the 1970s, only the den-2 virus was present in America, while today all four variants are present. Today, according to the WHO, dengue is endemic  to much of Central and South America, and also threatens many areas of the South of the United States.

CHIKUNGUNYA

Chikungunya is a viral disease, characterized by fever and severe pain, which is transmitted to humans by infected mosquitoes. The first known epidemic was described in Tanzania in 1952, although an epidemic in Indonesia had already been described in 1779, possibly attributable to the same viral agent.

After a 2-12 day incubation period, fever and joint pains are suddenly manifested as to limit patient movements (resulting in the name chikungunya, which in swahili means "what curves" or "contorts"), which so they tend to remain absolutely motionless and take antalgic positions. Other symptoms include muscle pain, headache, fatigue and skin rash. Pain in the joints is often debilitating, usually lasts a few days but may also last for a few weeks. In addition, chikungunya virus can cause acute, subacute or chronic diseases.

In most cases, patients recover completely but in some cases joint pain may persist for months or even years. Often the symptoms of infected people are mild and the infection may not be recognized or badly interpreted, especially in areas where dengue is present. Occasionally, ocular, neurological, cardiac and gastrointestinal complications have been reported. Serious complications rarely occur, but in the elderly the disease may be a cause of death.

Vectors and responsible agents

Identified in over 60 countries in Asia, Africa, Europe and the Americas, chikungunya is transmitted from person to person through the biting of a mosquito female like Aedes aegypti and Aedes albopictus (the tiger mosquito). The responsible virus belongs to the togaviridae family, the kind of alphavirus.

Treatment

There are no specific antiviral treatments and the treatment focuses primarily on relieving the symptoms. There is currently no vaccine against chikungunya.

ZIKA

The Zika virus was first isolated in Uganda in 1947 (by researchers from the Rockefeller Foundation who were studying the yellow fever) from Zika forest monkeys, near Lake Victoria. The first case of human infection dates back to 1968 in Nigeria and from 1968 to 2007 there were cases of human infection only in Central Africa and Southeast Asia. The first epidemic occurred in 2007 on the island of Yap (Micronesia), where 185 suspected cases were reported.

As of 2013, outbreaks have been reported in the Pacific Islands (French Polynesia - where the largest outbreak occurred, New Caledonia and Cook Islands). The first reports of neurological complications potentially associated with infection occurred during the outbreaks of 2013 and, during the spread in Brazil, an increase in microcephaly in endemic areas was observed since October.

The Emergency Committee of the International Health Regulations (IHR 2005) of the WHO, on February 1, 2016, said that the increase in the spread of the Zika virus and potentially associated with microcephaly and other neurological disorders reported by Brazil (and in the Americas) was an international public health emergency.

Symptoms

More than half of the infected do not have serious symptoms at first, which makes it difficult to detect the virus. After 3-54 days of contact with the insect you may suffer from high fever, headache, muscle pain, general fatigue.

Cure

There is currently no cure against the virus. Two Brazilian laboratories, the Butanta Institute of Sao Paulo and Fiocruz / Manguinhos in Rio De Janeiro are working on the development of a Zika vaccine, based on the Dengue platform.