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Dengue fever is a viral disease transmitted by the Aedes aegypti mosquito. It was first identified in Brazil in 1986. Estimates indicate that 50 million cases of dengue fever occur every year throughout the globe.


The main mode for contracting the disease is through the bite of Aedes aegypti mosquitoes. There are reported cases of mother-to-child transmission and through blood transfusions.  There are four strains of dengue viruses: DEN-1, DEN-2, DEN-3 and DEN-4.

Infection with the dengue virus may be asymptomatic, come with mild symptoms or cause severe illness, leading to death. Usually, the first sign of dengue virus infection is a high temperature (39° to 40°C), which starts abruptly and lasts from 2 to 7 days, alongside headache, bodily and joint pain, despondency, weakness, pain behind the eyes, rashes and itching.

Weight loss, nausea and vomiting are also common; in early stages, it may be difficult to diagnose it properly. This illness, in its most serious cases, may include intense and continuous abdominal pain, bleeding mucosal lesions, as well as other symptoms.

When presenting those symptoms, people must go to a health care unit.


There is no specific treatment for dengue fever. Treatment is carried out in order to alleviate the symptoms. When symptoms first appear, it is important to go to the nearest health care unit, rest and drink lots of fluids. One must not take medication on their own.

There is still not a vaccine or a specific medication against dengue fever. Therefore, the only method of prevention is to eliminate the mosquito, homes clean at all times and eliminating all possible breeding spots. Clothes that minimize skin exposure during the day, when mosquitoes are most active, do provide some protection against bites and can be adopted, especially during outbreaks. Repellents and insecticides can be applied provided that the instructions on the label are observed. Mosquito nets provide good protection for those who sleep during the day (for example, babies, bedridden people and night shift workers);

Actions aimed at controlling the dengue fever spread are mostly taken at the municipal level. When a breeding spot is identified and cannot be eliminated by the people living in a given location, the Municipal Health Department must be notified.



Chikungunya is a disease transmitted by the Aedes aegypti and Aedes albopictus mosquitoes. In Brazil, the circulation of the virus was first identified in 2014. Chikungunya means "those that bend" in Swahili, one of the languages spoken in Tanzania. This refers to the curved posture of patients during the first document outbreak, which occurred in Tanzania, in East Africa, between 1952 and 1953.

The main symptoms are high-rising temperature, severe joint pain in hands and feet, as well as fingers/toes, ankles and wrists. Also, headaches, muscle pain and red spots on skin can also occur. It's not possible to get infected with chikungunya more than once. After being infected, people are immune for the rest of their lives. Early symptoms usually appear between day 2 and day 12 after the mosquito bite. Mosquitoes acquire the chikungunya virus when biting an infected person during the period when the virus is present in the infected organism. Approximately 30% of the cases are asymptomatic.


There is no specific treatment for Chikungunya. Symptoms are dealt with through medication for fever (paracetamol) and joint pain (anti-inflammatory drugs). The use of acetylsalicylic acid (ASA) is not recommended due to the risk of hemorrhaging. Patients are recommended to rest and drink plenty of fluids.

Just as with dengue fever, it is essential that people reinforce all measures directed at eliminating breeding spots in their homes and in their communities. When a suspected case is notified, Municipal Health Departments must adopt actions in order to eliminate breeding spots in areas close to homes and places where patients are treated.


Zika is a virus transmitted by the Aedes aegypti mosquito, first identified in Brazil in April 2015. The zika virus received the same name as the location where it was first identified in 1947 - detected in sentinel monkeys used for monitoring yellow fever in the Zika forest in Uganda.


Approximately 80% of people infected with the zika virus do not develop any symptoms. Min symptoms include headache, low fever, mild joint pain, red spots on skin, itching and eye redness. Other less frequent symptoms are body swelling, sore throat, coughing and vomiting. In general, the evolution of the disease is benign and symptoms disappear spontaneously 3 to 7 days after infection. However, joint pain may continue for approximately a month. Serious and atypical cases are rare. When they do occur, however, they may exceptionally lead to death - as observed in November 2015 for the first time in history.

Pay attention to any signs and symptoms of zika virus infection and seek medical care if necessary.

The main mode for contracting the virus is through the bite of Aedes aegypti mosquitoes. Other possible modes for contracting the virus need to be further investigated, based on scientific studies. There is no evidence that the zika virus is transmitted through breastfeeding, or through urine, saliva or semen. According to studies carried out in French Polynesia, virus replication was not witnessed in breast milk samples, and this disease cannot be classified as sexually-transmitted as well. There are also no reports of transmission through saliva.

There is no specific treatment for zika virus infection. There are also no vaccines to fight the virus. The recommended treatment for symptomatic cases is based on the use of acetaminophen (paracetamol) or dipyrone in order to control temperature and alleviate pain. In case of itchy rashes, anti-histamines may be taken into account for treatment.

The use of acetylsalicylic acid (ASA)and other anti-inflammatory drugs is not recommended due to an increase risk of hemorrhage complications, as described in other flavovirus-caused infections. Suspected cases must be treated as cases of dengue fever, due to their increased frequency and attested severity.

› Use screens of doors and windows, wear long clothing items - pants and shirts/blouses. If you wear clothes that leave a large skin area exposed, apply repellent onto those areas.
Preferably stay in places with protective screens, nets or other barriers available.

› If you notice red spots on the skin, bloodshot eyes or fever, consult a health care service.
› Do not take any medication on your own.
› Seek orientation on reproductive planning and contraceptive methods at Basic Health Care Units.

› Make use of information available on institutional websites, such as the ones from the Ministry of Health and Health Departments.
› if you wish to have a child, seek orientation from health professionals and clarify any doubts you may have so you can make a substantiated decision.
› If you do not wish to have a child, seek out contraceptive methods at a Basic Health Care Unit.

› Use screens of doors and windows, wear long clothing items - pants and shirts/blouses. If you wear clothes that leave a large skin area exposed, apply repellent onto those areas.
Preferably stay in places with protective screens, nets or other barriers available.

› Go to a Basic Health Care Unit to begin your prenatal care as soon as you find out about your pregnancy and show up regularly for your appointments.
› Show up to your appointments once a month up to the 28th week of pregnancy; once every two weeks from the 28th to 36th week of pregnancy, and once a week from the 36th week of pregnancy until birth.
> Take all vaccines recommended for pregnant women.
> In case of fever or pain, go to a health care unit. Do not take any medication on your own.

› In case of any doubts, talk to you doctor or a health professional.
› Notify your doctor in case of any symptoms or medication being taken during pregnancy.
› Always carry your Pregnancy Card with you, as all of your pregnancy history can be found there.

› Protect the environment with screens on windows and doors, and try to keep the baby continuously dressed in long clothes - pants and blouses.
› Keep the baby in places with protective screens, nets or other barriers that are available.
› Breastfeeding is recommended until 2 years old or more, and exclusive in the first 6 months of life.
› If you notice red spots on the skin, bloodshot eyes or fever, consult a health care service.
› Do not give the baby any medication on your own.

› After being born, the baby will be assessed by health professionals at the hospital. The measurement of the baby's head (head circumference) is part of this assessment.
› In addition to the Routine Neonatal Screening (heel stick, hearing and eye screening), other tests may be performed.
› Take your baby to a Basic Health Care Unit to monitor the growth and development according to the childcare consultation calendar.
› Keep vaccinations up to date, according to the immunization schedule in the vaccination Booklet of the Child.

› Protect the environment with screens on windows and doors, and try to keep the baby continuously dressed in long clothes - pants and blouses.
› Keep the baby in places with protective screens, nets or other barriers that are available.
› Breastfeeding is recommended until 2 years old or more, and exclusive in the first 6 months of life.
› If you notice red spots on the skin, bloodshot eyes or fever, consult a health care service.
› Do not give the baby any medication on your own.
› Take your baby to a Basic Health Care Unit to monitor the growth and development according to the childcare consultation calendar.
› Keep vaccinations up to date, according to the immunization schedule in the vaccination Booklet of the Child.

› In addition to routine monitoring in the Basic Health Care Unit, your baby needs to be sent for early stimulation.
› If the baby presents alterations or complications (neurological, respiratory or motor, among others), monitoring by different specialists may be necessary, depending on each case.


Among people infected with the zika virus (adults and children), approximately 80% present no symptoms. Among these people, only a small share may present some kind of complication, which shall be assessed by physicians, once zika fever is a new illness and its complications have not been fully describes yet.

Studies on other possible modes for contracting the virus need to be further investigated. These analyses must be accompanied by scientific studies so that the Ministry of Health can provide the population with assured orientations on the transmission of the virus. The Ministry of Health has been monitoring the status of the zika virus across the globe through the Pan American Health Organization (PAHO/WHO) and other international organizations.

Other viruses similar to the zika virus generate immunity for life. People who have had type-1 dengue fever, for example, will not have this type of dengue fever again. The same thing applies to the yellow fever virus. However, there are not enough studies so this can be confirmed with regard to the zika virus.

Zika virus X Microcephaly

Microcephaly is a congenital malformation in which the brain does not develop properly. In this case, babies are born with a cephalic perimeter smaller than usual - that is, equal or smaller than 32 cm. This congenital malformation may be the results of various factors, such as chemical substances and biological (infectious) agents, such as bacteria and viruses, as well as radiation.

The Ministry of Health has confirmed the relationship between the zika virus and microcephaly. The Evandro Chagas Institute, an agency of the Ministry of Health in Belém do Pará, forwarded the results of exams carried out with a baby born in Ceará with microcephaly and other congenital malformations. The presence of the zika virus was identified in blood and tissue samples. This is an unprecedented in scientific research studies across the globe.

The investigations on the matter, however,  continue to take place to clarify issues such as the transmission of this agent, its activity in the human body, the infection of the fetus and the period of greatest vulnerability for pregnant women. Initially, the risk is associated with the first trimester of the pregnancy. This finding reinforces our urge to call for a national mobilization effort aimed at retraining the Aedes aegypti mosquito - responsible for disseminating the illness.

After the baby is born, the first physical exam is a routine exam carried out in all maternity wards, which should be executed within 24 hours after birth. This is a key moment for actively investigating the presence of possible congenital abnormalities. It is also possible to diagnose microcephaly during prenatal care. However, only the physician that has been monitoring the patient in question can indicate the most adequate imaging test. 

At birth, suspected cases of microcephaly shall be subject to physical exams and measurements of the cephalic perimeter. Microcephaly is diagnosed in full-term babies born with a cephalic perimeter smaller than 32 cm. They shall be subjected to neurological exams and imaging test, with the transfontanel ultrasound being the first option - only resorting to a tomography when the fontatel is closed. For premature babies, microcephaly is diagnosed when babies are born with a cephalic perimeter smaller than 2 standard deviations.

There is no specific treatment for microcephaly. There are support actions that may assist in babies' and children's development, and this monitoring is a prerogative of the Unified Health System (SUS). In order to guide treatment, from prenatal care to the development of children with microcephaly, the Ministry of Health developed the Protocol for Attention to Health and Response to Occurrences of Microcephaly Related to Zika Virus Infection. This document provides for the mobilization of health professionals, specialists and managers in order to promote early diagnoses and specialized cared for pregnant women and babies.

The Protocol also defines the guidelines for early stimulation of all newborns with microcephaly. All confirmed cases of children with his congenital malformation must be registered with the Early Stimulation Program from birth until 3 years of age - when the brain develops more quickly.
Early stimulation aims at maximizing the potential of every child, encompassing physical development and neurological, behavioral, cognitive, social and affective maturing, all of which may be damaged by microcephaly.
Babies born with microcephaly shall receive early stimulation care at rehabilitation centers throughout the country - at Specialized Centers for Rehabilitation (CERs), Centers of Support for Family Health (NASFs), and Outpatient Centers for Newborn Monitoring.

Approximately 90% of the cases of microcephaly are associated with mental retardation - except in cases of family history - which can present a regular cognitive development. The type and severity of these complications vary according to the case at hand. Treatments carried out since very early age can improve children's development and quality of life.

French Polynesia reported an unusual increase - at least 17 cases - in Central Nervous System malformations in fetuses and newborns in 2014 and 2015, which coincided with the zika virus outbreak in French Polynesia. None of the pregnant women reported symptoms of zika virus infection. In four women, however, flavivirus antibodies (IgG) have been found in serology, which suggests asymptomatic infections. Similarly as Brazil, French Polynesian health authorities also believed that the zika virus could be associated with these congenital malformations in case the pregnant women were infected during the first or second trimester.

According to the cases reported so far, pregnant women whose babies were diagnosed with microcephaly presented zika virus symptoms in the first trimester of their pregnancy. However, precautions in order to prevent contact with the Aedes aegypti must be taken during the entire pregnancy.

The Ministry of Health strongly advises pregnant women to not use medication not prescribed by health professionals, that they have proper prenatal care and carry out all recommended exams, and that they notify health professionals should they perceive any alterations during their pregnancy. It is also important that they reinforce all precautions against the Aedes aegypti, using repellents suitable for use during pregnancy, wearing long-sleeved clothes and all other measures necessary in order to avoid contact with mosquitoes, in addition to prevent stagnant water from accumulating at home and in the workplace. Regardless of their destination or reason for travel, pregnant women must check in with their physicians before traveling.

Check out the orientations for pregnant women..

It is important that health professionals carefully assess cephalic perimeters and gestational age, and that they notify suspected cases of microcephaly through birth registration carried out with the Live Births Information System (SINASC). As sources of direct contact with the population, professionals must also stress alerts on the precautions to be taken to avoid the proliferation of the mosquito, providing guidelines to pregnant women on individual protective measures against the Aedes aegypti.

In addition to notifying SINASC, the Ministry of Health issued a guideline so that this registration is carried out using a specific form, adopted on an exceptional basis, which can provide more detail on the cases being investigated.

Access the monitoring and assistance materials for health professionals and managers..


The Aedes aegypti is a domestic mosquito, which lives inside homes and near populations. It has daytime habits and feeds on human blood, especially at dawn and dusk. Reproduction takes place in clean, stagnant water from the eggs laid by the females. Eggs are laid in clean, stagnant water and spread over several breeding sites - a strategy that guarantees the propagation of the species. If female specimens are infected with the dengue virus when they lay their eggs, it is possible that the larvae will hatch and be already infected with the virus as well - which is called vertical transmission.

Female mosquitoes need blood to produce eggs. Both males and females feed on substances that contain sugar (nectar, sap, etc.) - however, since males do not lay eggs, they don't require blood.

Yes, because the Aedes aegypti bites people preferably on their legs and feet. They avoid light and are attracted by the heat; therefore, they tend to prefer dark-colored fabrics. The important thing is to eliminate breeding spots so that they can spread.

Aedes aegypti originates from Egypt. His spread across the world started in Africa: first from the African East coast to the Americas and then from the Western Coast to Asia. The Aedes genus was first described only in 1818. It was soon verified that the aegypti species, describes a couple of years earlier, presents morphological and biological characteristics that are similar to other species of the Aedes genus, instead of the Culex genus, which was much more known. Then, the name Aedes aegypti was coined.

Female mosquitoes suck on blood to produce eggs. If the mosquito is carrying the dengue virus, it can transmit the virus in the meantime. In general, mosquitoes suck on the blood of one person at each set of eggs produced. However, it is capable of biting more than one person for a single set of eggs. There are reports of a single mosquito carrying the dengue virus transmitting dengue fever to five people of a single family on the same day.

Most accepted theories indicate that the Aedes aegypti came from Africa to the Americas via slave ships that were bound for Brazil. There are records of the illness in Curitiba (PR) in the late 19th century and in Niterói (RJ) in the early 20th century.


The information that there is a relationship between the zika virus and mosquitoes infected with the Wolbachia bacterium is not true. Since 2014, Fiocruz - in partnership with the Ministry of Health - has been developing the "Eliminating the dengue fever: A challenge for Brazil" project, which proposes using a bacterium - named Wolbachia - that is naturally found in the environment, including within mosquitoes. When present within the Aedes aegypti mosquitoes, this bacterium is capable of preventing the mosquitoes from transmitting dengue fever and chikungunya.  This non-profit initiative is an innovative approach used to reduce the transmission of the dengue virus by Aedes aegypti mosquitoes in a natural and self-sustainable way. This study is unprecedented in Brazil and Latin America. This study has been successfully carried out previously in Australia, Vietnam and Indonesia.

The Ministry of Health clarifies that all vaccines provided through the National Immunization Program (PNI) are safe and that there is no evidence in national and international literature indicating that vaccines may cause microcephaly. The PNI is responsible for providing States with all immunobiologicals that are part of the vaccination schedule. One of the most important tools for the success of the immunization programs is the assessment of the immunobiologicals' quality. Quality control of the vaccines is carried out by the manufacturing lab, in compliance with criteria set forth by the World Health Organization (WHO). After approval in control tests carried out by the manufacturing lab, each batch of a given vaccine is analyzed by the National Institute for Quality Control in Health Care (INCQS), from the Ministry of Health. Since 1983, batches of immunobiologicals acquired through official immunization programs - and sorted by sampling - have been analyzed, assuring their safety, potency and stability before being applied to the population.

We must highlight that there are no reports in this notification system regarding a connection between microcephaly and vaccines, as there is no evidence in national and international literature indicating an association between vaccines and microcephaly.

The Guillain-Barré syndrome is a reaction to infectious agents - such as viruses and bacteria - having as a main symptom muscle weakness and paralysis. Symptoms start on the legs and may subsequently affect the torso area, upper limbs and the face. This syndrome may present several levels of severity, ranging from mild muscle weakness in some patients to total paralysis of four limbs in other cases. The main risk of this syndrome is when the respiratory muscles are affected, which results in difficulties to breathe. In this case, this syndrome may lead to death if respiratory support measures are not adopted. The zika virus may cause the development of the Guillain-Barré syndrome. The Guillain-Barré syndrome is a rare condition. As will all possible zika virus-related consequences, the occurrence of the Guillain-Barré syndrome is continuing to be investigated.

The Federal Government will distribute repellents to all pregnant women who are registered with the Bolsa Família welfare program. The Government is contacting repellent manufacturers in order to precisely define the volumes that the segment is capable of offering.

All the cases of children with microcephaly related to infection with the zika virus will be investigated. The change in the cephalic perimeter parameters (equal or smaller than 32 cm) is in accordance with a recommendation issued by the World Health Organization (WHO), which is endorsed by the Brazilian Society of Medical Genetics and supported by the SIAT (National Information System on Teratogenic Agents). It must be clarified that the Ministry of Health has adopted 33 cm as the new measurement - which is completely normal for children born after 37 weeks - with the purpose of better understanding the increase in the cases of microcephaly. From a preliminary screening of these suspected cases, several early and preventive diagnoses have already been ruled out as cases of microcephaly. Therefore, this new measurement aims at expediting clinical procedures, without disregarding the babies that have been included in the first list of suspected cases.

The Oswaldo Cruz Foundation (Fiocruz), an institution linked to the Ministry of Health, has identified active zika virus (with the potential to cause infection) in saliva and urine samples from patients. However, this is not enough to say that the virus can be transmitted through the saliva. Other studies are necessary to analyze, for instance, what is the survival window of the zika virus and it can infect people even after being exposed to gastric juices. So far, the recommendations are for precaution and prevention purposes - with orientations used for other illnesses: avoid sharing personal objects (toothbrushes and glasses, for example) and wash hands. Most precautions must be taken by pregnant women, as they must protect themselves against the Aedes aegypti mosquito.

The Ministry of Health only uses larvicides that are recommended by the World Health Organization (WHO). The products undergo a rigorous process of evaluation from the World Health Organization Pesticide Evaluation Scheme (WHOPES). There are no epidemiological studies that attest for the association between the use of pyriproxifen and microcephaly. Some locations that have not made use of pyriproxifen, for instance, have also had reported cases of microcephaly. Pyriproxifen is approved by the WHO and by the National Health Surveillance Agency (Anvisa). The Ministry o Health only recommends the use of larvicide in special situations - whenever there is the need to store water and storage facilities cannot be physically sheltered.

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