​​Pathophysiologic Analysis of Microcephaly Causative Agent​

The Zika virus is the main causal agent of a condition known as microcephaly in infants. The virus is transmitted by two types of mosquito species – Aedes aegypti and Aedes albopictus (Symptoms, Diagnosis & Treatment, 2015.) Zika virus, as the name suggests is a biological agent and a viral one at that.

When zika virus first enters a human host, there are often no visible symptoms until after approximately ten (10) days (Martines, 2016; Hayes, 2009.) There are other studies that peg the incubation period at two (2) weeks. Initial symptoms include but not limited to fever, rash, arthralgia, and conjunctivitis to mention but a few (Martines, 2016.) Currently, the Centers for Disease Control (CDC) has only identified pregnant women and those of childbearing age as the most at-risk population. There have been outbreaks in parts of West Africa in the past but the deadliest so far has been in Brazil specifically in the more impoverished regions especially in the northeastern parts (Zanluca et al., 2015.) Besides the bite of various species of aedes mosquito, the zika virus is also suspected of being transmitted through sexual intercourse (United States, 2016; Meaney-Delman et al., 2016.)

When a pregnant woman gets bitten by any of the vectors - Aedes aegypti and Aedes albopictus – the virus is transmitted to the baby and over time there is abnormal development. When the mother contracts the virus, the baby develops a smaller head size which consequently results in microcephaly – a condition which according to the Centers for Disease Control (CDC) results in underdeveloped and smaller brains in infants (Martines, 2016; Mlakar et al., 2016.)

The zika virus is a ribonucleic acid (RNA) virus which contains ten thousand seven hundred and ninety-four (10,394) nucleotides and responsible for producing about three thousand four hundred and nineteen (3,419) amino acids (Hayes 2009.) After the incubation period, when the human host begins to show signs of infection, the symptoms of zika virus presented are comparable to that of certain viral diseases such as dengue fever and chikungunya. Due to the similarities in symptomatology, medical experts often have to carry out further analysis on bodily fluids isolated from individuals suspected of carrying zika virus (Mlakar et al., 2016) in order to prove beyond all reasonable doubt the existence or otherwise of the presence of the zika virus. The most notable test used in detecting zika virus is the reverse transcription-polymerase chain reaction (RT-PCR) test (Martines, 2016.) RT-PCR is used in the detection of RNA expression and since the zika virus is an RNA molecule, the test is an appropriate one.

Regarding an intrauterine infection – infection of a fetus – the brain and eye are the main organs affected by the virus as is shown by a case study published in the New England Journal of Medicine (Mlakar et al., 2016.) Available evidence suggests that if a mother becomes infected with the zika virus while pregnant, the baby’s development is retarded in terms of its weight and so does the Central Nervous System (CNS). The autopsy of a terminated pregnancy shows a hardening of the viral remains in such places as the placenta and the brain as well as the eye of the developing fetus (Mlakar 2016.) Further analysis using an electron microscope showed extensive atrophy of cerebral neurons and neuron structures. The destruction is suspected to have been triggered through the action of viral contact with neural structures in the brain which was signified by the presence of calcified remains (Mlakar 2016.) Besides microcephaly, brain atrophy, enlargement of the ventricles of the brain as well as intracranial calcifications are some of the conditions that a fetus suffers from zika virus infection (Meaney-Delman et al., 2016)

Considering the population under discussion, the main problems presented by infection with zika virus is microcephaly and according to the CDC, there are two forms of the condition: mild and severe microcephaly. With severe microcephaly babies tend to have very serious problems with their auditory, visual as well as their central nervous systems (Facts About Microcephaly, 2016.) Due to the seriousness of the co-occurring conditions, severe microcephaly can cause the baby to die (Facts About Microcephaly, 2016) especially since they also tend to have very low birth weight as well (Mlakar, 2016.) Mild microcephaly on the other hand is a little bit more manageable as long as the baby is well monitored from birth and regularly afterwards; but that can be very costly especially in the part of Brazil the virus has attacked the most.

Part 2

The main reason behind the rapid spread of the zika virus in a place like Recife in the northeastern region of Brazil, is the abundance of the aedes mosquito population (Life at zika epicenter a struggle for afflicted family, 2016.) According to the Associated Press, residents of Recife have always had a high mosquito population to the extent that it has almost become a normal aspect of daily life. In other words, exposure to the vector has been around for generations but the first case of zika virus in Brazil was reported in May of 2015 (Martines 2016.) Since then, there has been a rapid infection rate within the northeastern regions of Brazil and even surrounding countries (Martines 2016.)

The high population of the aedes mosquito is due to stagnant water not being drained (Life at zika epicenter a struggle for afflicted family, 2016.) The puddles of water are not the only problem. According to reports, the climate in the northeastern part of Brazil is such that rain falls frequently; coupled with that is the free flow of sewage in close proximity to residential areas. The combination of sewage, stagnant water – and the abundance of it, considering the amount of rainfall – creates the perfect breeding ground for the increasing aedes mosquito population. In addition to that, due to the socio-economic status of most of the population, there is a necessity to store water in tanks and other large vessels. Since the storage of water is not done right, and is attributable to inadequate purification equipment and even knowledge, that also soon enough becomes breeding ground for the aedes mosquito (Life at zika epicenter a struggle for afflicted family, 2016; Meaney-Delman et al., 2016) Due to the abundance of the vector, – aedes mosquito – stemming from unclean surroundings, improper sewage and trash disposal, residents are at an increased risk of getting bitten by a zika virus-carrying aedes mosquito and consequently suffer the disease.

As disease-carrying organisms, mosquitoes often transmit causative agents by breaking the skin of their potential host with their proboscis (McKay, 2016; Hamel et al., 2015.) Once the skin is broken into by the proboscis and the virus is released, the defense mechanisms in place to counteract infection have been found to be unable to carry out their functions. Such skin defenses as fibroblasts, epidermal keratinocytes to mention but a few (Hamel et al., 2015.) The inactivation of skin defense system contributes to the proliferation of the virus within the body.

In the case of zika virus, there are at least three other means of transmission. Sexual intercourse with an infected male partner is likely to lead to an infection (United states: CDC reports link between zika virus and microcephaly in brazil 2016) due to the length of time the virus is able to stay in semen, which according to research is currently unknown (Meaney-Delman et al., 2016.) For most of the pregnant women in the northeastern region of Brazil, which has become known as the “ground zero” of the recent outbreak (Petroff, 2016), the rapid spread of zika virus resulting in birth defects could also be attributed to sexual intercourse. As if that is not enough, there is growing concern of spread through blood transfusion (United states: CDC reports link between zika virus and microcephaly in brazil, 2016) for which reason efforts have been ramped up in a bid to ensure that the blood banks do not accept blood donations from individuals who have been to or have had contact with acquaintances returning home from visiting the northeastern regions of Brazil such Recife and Salvador.

In essence, tracing the exposure pathway begins with the improper disposal of trash and sewage. The inaction on the part of government officials and residents to drain stagnant puddles of water which serve as breeding grounds for the aedes mosquito results in an increase in the population of the vector (United states: CDC reports link between zika virus and microcephaly in brazil 2016.) Since the likelihood of zika virus being present is high, contact with a potential human host is equally high thereby increasing chances of infection.

The risk of contracting the virus and suffering the debilitating conditions associated with it, qualifies pregnant women and their unborn children as sensitive subpopulations. It therefore calls for action on the part of the international community to allocate resources to fight the epidemic. The World Health Organization has recently announced that the outbreak of zika virus is an issue which warrants the attention of the international community (European union: Zika virus outbreak - environment committee debate with WHO on Wednesday, 2016; McKay, 2016.) There have been many warnings issued by local government officials in the northeastern region of Brazil to delay pregnancy for the foreseeable future (Health officials probe tie between zika, paralyzing syndrome, 2016) in order to reduce the number of children already suffering from the destructive and often expensive-to-treat microcephaly. Since most of the men, women and families in the affected areas are not as high up on the socioeconomic ladder as other places in Brazil, their health is already in jeopardy and it therefore makes sense for them to delay pregnancy in order to reduce the potential economic burden that the zika virus can pose to them.

There have been concerns raised about a possible link between zika virus and a fatal form of autoimmune disease called Guillain-Barre syndrome. The disease causes the body’s own immune system to attack itself, specifically the peripheral nervous system thereby causing damage to muscles that aid in movement (Health officials probe tie between zika, paralyzing syndrome, 2016.) In the city of Salvador, which used to be called Bahia, there have been reported cases of Guillain-Barre syndrome in patients who initially presented with the classic symptoms of the zika virus – rash, fever and arthralgia. There were forty-six (46) cases total and out of that exactly twelve (12) of them reported the classic symptoms of zika virus before the onset of paralysis due to Guillain-Barre syndrome. It is due to the accompaniment of the classic zika virus infection symptoms to Guillain-Barre syndrome that experts now suspect a possible link between both conditions (Health officials probe tie between zika, paralyzing syndrome, 2016.)

Due to the health complications suffered by newborn babies of infected mothers, there has been talk of abortion as an option for interested pregnant women if they discover their unborn child is going to suffer from microcephaly (Barchfield, 2016.) Legal experts have weighed in and the conclusion is to allow women whose unborn children have severe microcephaly to proceed with the abortion even though it is generally illegal in Brazil. On the other hand, it raises ethical and moral questions for medical doctors, causing religious leaders to weigh in on the issue. There is strong opposition from the religious leaders (Barchfield, 2016) who believe in the sanctity of life. The sensitive subpopulation in the affected regions of Brazil face a lot of stress from the financial costs in taking care of themselves and their children which in itself can take a toll on their health.

There is cause for concern for a number of reasons. Economically, productivity could be severely impacted. The rate of infection has increased so much that there are many babies affected. The number of infected pregnant women who could transfer the virus to their unborn babies has increased as well. If nothing is done to contain the situation, there will likely be a good chunk of an entire generation who will have developmental abnormalities. Abnormalities that will have the potential to disrupt economic activity through reduction in quality and quantity of the workforce.