Can Polio be Eradicated?

Polio or Poliomyelitis was recognized as a condition in the 1840 and the causative agent of the disease was identified in 1908.

The disease well known for its paralysing condition for limbs had affected populations from Asia, Africa, the Americas, and Europe.

Efforts to control and eradicate the disease resulted in the development of the polio vaccine in the 1950’s. Since then vaccinations have been administered to vulnerable populations worldwide.

By the year 2000, the continents of America were declared polio free, and in 2002, Europe was declared Polio free.

What causes polio?

Polio is caused by three virus types/strains, these are wild polio virus 1 (WPV1), WPV2 and WPV3.

Wild polio virus type 2 (WPV2) was eradicated worldwide in 1999 while WPV1 and WPV3 still remain in circulation.

Until March this year, polio was endemic in four countries,  Afghanistan, India, Pakistan, and Nigeria but India was removed from the list by the Global Polio Eradication Initiative being free of any polio cases for 1 year. If there will be no other polio cases in India for another year, that is 2 continuous years then India will be declared free of polio.

Despite this milestone for India, there are still outbreaks of polio in Afghanistan, Pakistan and Nigeria. Re- established transmission and imported transmission cases of polio have been observed in neighboring countries of the endemic areas as well as surrounding countries. For example in Angola, Chad and DRC there has been re-established transmission of the disease while the virus has been imported to Central African republic, China, Congo, Cote d’Ivoire, Gabon, Guinea, Kenya, Liberia, Mali, Niger and Uganda.

What is the difference between re-established transmission and imported transmission?

 Re-established transmission is when an outbreak to the virus re-emerges within the population due to either missed booster vaccinations within a population which was previously free of the virus while imported transmission of the virus is usually outbreaks from a virus brought in from endemic countries to other areas through migration of infected individuals.

Advances in science have allowed for easier identification as well as tracking the origin of the virus during outbreaks. This has been made possible through genome sequencing of polio virus from patients in outbreak areas, by comparing the results with previously sequenced polio viruses from other regions, one is able to track where the virus could have originated from.

Is it possible to eliminate polio globally?

This is the question that was posed many years ago and since the onset of the disease people have been working hard to eradicate the disease. The development of the polio vaccine helped accelerate the efforts of control and eradication of the disease. Despite the milestones in polio eradication in Europe and the Americas there are still challenges to the eradication of the disease in parts of Africa and Asia.

Re-emergence of polio in countries and areas where the disease was eliminated has raised fears especially in the continents where there are still countries where the disease is endemic. 

Porous borders have contributed to some of the outbreaks in areas which were declared polio free. Free movement of people from endemic areas who have not been vaccinated against the disease into disease free areas increase the risk of infection or re-infection, hence countries have to be aware of this risk.

Responses to outbreaks and administration of the polio vaccine are crucial in controlling the spread and elimination of the disease. In India door to door vaccination helped to vaccinate at least 1 million people per month and was proved to be a great success. Even though this method worked for India, vaccination campaigns have been challenged in parts of Pakistan and Afghanistan due to political unrest which present a security risk to both health workers and the people living in the region. Misconceptions such as those that the polio vaccine is meant to sterilize people have also contributed to non-compliance in certain communities.  It has been reported that people in the regions where there is war and political unrests many children have missed out on their polio vaccine and booster vaccine putting the population at risk of contracting the disease.

In Africa, the west Africa region has experienced re-established transmission of polio (Angola, Chad and Democratic Republic of Congo) as well as cases of the virus being imported into neighboring countries (Central African Republic, Congo, Cote d’Ivoire, Gabon, Guinea, Kenya, Liberia, Mali, Niger and Uganda). With Nigeria being the only remaining country in Africa where Polio is endemic, migration and cross border trade with neighboring countries offers a high risk of transmission of the disease. Political unrests in some of the African countries mentioned above have also hampered vaccination campaigns leaving populations at high risk of the disease.  There are still many areas where health works cannot reach to administer the vaccine due to security risks. Non- compliance by certain groups of people also increases the danger of re-infection and affecting the eradication process.

So what should be done to eradicate this disease?

It is crucial for governments and organizations working towards eradication of polio to provide resources and set up measures for surveillance to monitor and administer the polio vaccine. Most important is the involvement of the community through civic education on the dangers of polio and the importance of vaccination.  In several communities it has been observed that people listen more to their local authorities than their health workers especially when there is some negative myths associated with the Polio vaccine.  Village chiefs, religious leaders, tribal leaders, business leaders and other people with authority in the communities are crucial in disseminating information to the communities.

In refugee and natural disaster camps, the UN and their partner Rotary international are working hard to vaccinate children against Polio , an example is that of Somalia, despite all the hardships the country is going through, there are no reported polio cases.

There is still hope that polio will be eradicated, but joint efforts between governments, non -governmental organizations and the population at large is crucial for this to happen. It is our responsibility, each and every one of us to ensure that polio is eradicated globally. Each one of us has to make sure that the people around them, the people they know, friends and family have been vaccinated against polio. Together we can fight polio.

To read more on what is going on around the world regarding polio eradication, visit the Global Polio Eradication Initiative website on http://www.polioeradication.org/

Dengue in the Pacific

Dengue fever is a tropical disease caused by the dengue virus. The virus is transmitted by several mosquito species from the genus Aedes.

There are four different virus types known as serotypes that cause dengue fever; DEN-1, DEN-2, DEN-3, and DEN-4. If an individual is infected by any one of the four virus serotypes, they develop immunity to that specific type that they were infected with. This means that there is no cross immunity between the serotypes, so for example if an individual is infected by DE-1, they will develop immunity for DEN-1 but NOT DEN-2, DEN-3, and DEN-4.

Dengue fever dates back in the 1700 but increase number of cases have been observed since the 1960’s with the disease being endemic to over 110 countries and infecting close to 100 million people every year.

What are the symptoms of dengue fever;

-fever

-headache

-muscle and joint pains

-a characteristic skin rash that is similar to measles

- Sometimes a more severe form of the disease may occur, these include dengue haemorrhagic fever which includes symptoms such as bleeding, low levels of blood platelets and blood plasma leakage.  Another severe form of the disease is dengue shock syndrome where the blood pressure drops dangerously low.

Dengue fever is ranked by the World health organization as one of the neglected diseases.

The incidence of dengue fever has increased over the years, the increase has been attributed to urbanization, population growth, increased in international travel and global warming.

In this article I will discuss some of the countries that have been affected by Dengue with increased international travel as one of the contributing factors.

In the pacific island countries and territories (PCITs), dengue is not endemic but several outbreaks have occurred over the years. The largest number of epidemics observed have been due to DEN-1 and DEN-2 serotypes.  DEN-1 affected 16 PCITs between 2000 and 2004.

From the beginning of May 2012, a dengue outbreak has been declared in some of the PICTs including New Caledonia, Kiribati, and Cooks Islands.

What are the factors facilitating dengue outbreaks in the PCITs?

Some of the factors that have been put forward to facilitate these outbreaks include;

1.       Lack of effective prevention activities in many PICTs.

2.       Inadequate diagnosis

3.       Limited surveillance for cases and the vector (the mosquito that transmits the virus).

4.       Lack of capacity to respond to outbreaks due to insufficient trained personnel and resources to implement control and prevention plans.

Sequencing of the dengue virus has been done and sequences are available for researchers for reference as they compare various outbreaks and the responsible virus serotype.

Genetically Modified Mosquitoes: What does this mean to the population?

Mosquitoes are one of those insects which have caused a lot of havoc in communities and societies. This insect not only has a painful bite but also through the bite, it transmits some of the most dangerous infectious diseases on the planet. Not all mosquitoes transmit diseases.

Scientifically living things are classified or grouped systematically for easy identification and comparison with other living things just as we humans use names, and other unique features to identify ourselves.  As such if we use our day to day scenario, every living thing belongs to a clan, and in this clan there are families, and each family is known by its own name (surname) and then the families have children or offspring, who have their own unique names. Scientifically living things are also classified in a similar manner, each plant or animal belongs to a “clan” know as a FAMILY, and the “families” in the “clan” are known as GENUS, which like the “surname” of the family  and the “unique names” of the children and offspring is what is known as SPECIES. So when we say that malaria is caused by the parasite Plasmodium falciparum,  all we are trying to say is that the parasite belongs to the GENUS- Plasmodium and the SPECIES falciparum.

The reason why I had to take you back to this systematic class of biology, where we learn how living things are classified, is because today’s article will involve some of these terminologies that I just introduced.

As I mentioned earlier, some mosquitoes transmit diseases which are and have been big Public health problems.  When it comes to diseases in the tropics and subtropical regions, mosquitoes from the genus Aedes and Anopheles transmit some of the most dangerous infectious diseases in the world.

Some of the species of Aedes transmit Dengue fever, yellow fever, and human lymphatic filariasis.  Aedes aegypti causes yellow fever and a lot of research has been done to understand this mosquito. With the advancement in technology, scientists have sequenced the DNA (which contains all the information of how and what a living thing is made up of (Genome)) from these mosquitoes in order to find ways and means to understand them better and also how they carry and transmit these diseases.

Anopheles is another genus of mosquitoes which is well known with transmission of diseases. Of the 460 known species of Anopheles, 100 can transmit human malaria. Anopheles are vectors (transmit the parasites, bacteria, viruses,and worms which cause disease) for canine heart worm, Wuchureria bancrofti (which causes filariasis), Brugia malayi and viruses e.g. those that cause O’nyong’nyong fever.

Just as Aedes aegypti, the sequence for Anopheles gambie genome, the worlds most important malaria vector has been published.

As technology is advancing by the day, hour, minute, scientists have and are working hard manipulating the genomes of sequenced vectors in order to stop them from transmitting the diseases. The genetic manipulations also known as genetic modifications involve playing around with parts of the genome in order to either sterilize the vector, stop the vector from further reproduction (suicide genes) and many more.

Some weeks back there was a story where a biotech company has released genetically modified mosquitoes into the environment. These mosquitoes carry a “suicide” gene where if they mate with the female mosquitoes they will not be able to produce offspring and the mosquito population will die out. As simple as it sounds the consequences in the long term are unknown and that is where the danger is.

Most of the genetic modifications are done in controlled environments in laboratories, where these experimental animals are monitored. But when these insects are released in the environment we have no idea, what mutations (changes in the DNA which may result in changes in behavior of a plant or animal) may come up.  How will the companies monitor or follow these mosquitoes once released? Are they tagged so that they could easily trace their movements? Flying insects can easily cross borders into other regions is there any awareness in the communities where the mosquitoes have been released and the neighbouring communities which could be victims of these mosquitoes? What dangers do these genetically modified mosquitoes present to society?

What are the long term effects?

There are many questions we can ask.

Is it worth it to have these genetically modified insects released in our societies when we don’t fully know the consequences they will have in our environments? Yes we have diseases which are killing our populations and we are desperate to get rid of them, but is this the right way? Are we not adding another complicated problem on top of an already existing problem?

I am not against advances in science but let us not use desperate situations as a reason to try out unfinished products. Developing countries have been a dumping ground of many experiments whose long term effects are unknown. Infectious diseases are already causing havoc in developing countries let us not add more problems, but let us find ways to solve these problems.

Have your say, I would like to hear your opinions on this.

Can Stigma be Conquered?

The first time I heard of the word stigma was at the onset of the HIV/AIDS pandemic. This word was everywhere, on the radio, in newspapers, in brochures and posters but I did not understand what it meant.

With time I began to get the idea what this word was all about. It was a word that brought fear in every one who was HIV positive and to those who were not sure whether they had the disease or not.

So what is stigma?

AIDS-related stigma and discrimination is described as prejudice, negative attitudes, abuse and maltreatment directed at people living with HIV and AIDS.

Different societies and cultures have shown varying levels of stigma and discrimination and these in turn have instilled fear in people of being discriminated against. This fear has resulted in people running away from knowing their HIV status and disclosing their HIV status if they know it.

Governments and non-governmental organizations are working hand in hand with many African countries where the disease has caused a lot of havoc, to bring awareness on the disease.

In the beginning it was not easy to break the cultural barriers and talk about issues concerning sexuality which are considered as taboo. But as the disease claimed more lives and infections sky rocketed people resorted to opening up and bringing the truth about HIV/AIDS into the open. HIV/AIDS has created thousands and thousands of orphans in Africa and as such communities are working hard to bring awareness of the disease to both young and old.  In Malawi for example, children in primary school (between the age of 5 and 12) and in secondary school (12-18years of age) are taught about the danger of HIV/AIDS and how they can contract it as well as avoid infection. In the rural areas, health personnel and social workers are working hard to bring awareness on HIV/AIDS.

But how has this awareness affected the issues of stigma and discrimination in these societies?

Uganda was badly hit by the pandemic but the country embarked on huge HIV/AIDS awareness campaign which showed remarkable results in the society, their perception of the disease as well as stigma and discrimination.

In Malawi, I noticed that people are more open to talk about their HIV status, they are also open to tell their friends and family members to go for HIV testing if they suspect the disease. The interesting thing that I noted was people will say “ it is better to go and get these free medication and stay alive than hide the disease and die from it”. This attitude has helped many people to come in the open and get treatment. There are still some who do not want to know their HIV status and even if they see all the symptoms leading to HIV/AIDS they would still deny being tested.

A study in Botswana showed that stigmatising attitudes lessened three years after the introduction of the national program providing access to treatment.  A reduction in stigma was also observed in Tanzania with the introduction of the antiretroviral treatment (ART).

The Secretary general of the UN, Ban Ki Moon said and I quote “ Stigma remains a single most important barrier to public action. It is a main reason why too many people are afraid to see a doctor to determine whether they have the disease, or to seek treatment if so. It helps make AIDS the silent killer, because people fear social disgrace, of speaking about it, or taking easily available precautions. Stigma is a chief reason why the AIDS epidemic continues to devastate societies around the world.”

So can stigma be conquered? I believe the answer lies with each and every one of us. If we have to fight the HIV/AIDS pandemic, we need to work together against stigma and discrimination.

Control of Zoonotic Diseases

Due to the increase in incidence of zoonotic diseases around the world, efforts have been made and are still being made to control zoonotic diseases.

Since zoonoses involve both humans and animals, efforts to control the diseases require working both with the health and veterinary sector. In as much as these two sectors have to work hand in hand, there is a very important aspect that we also have to consider in order to control these diseases, that is the communities involved.

In the past efforts have been done to control many infectious diseases but unfortunately the most crucial part is always left out until the last minute. Community involvement has always been left out until the last minute when an epidemic has hit or when there is an outbreak. Unfortunately when the disease has been controlled it is all forgotten. There is therefore need for continuity in community involvement to achieve effective control of zoonoses.

With zoonoses being spread from animal to humans through meat, animal products and animal excreta from both wild and domesticated animals, we have to go down to the grass roots, that is the people who live in close proximity with wild and domesticated animals. But who are the people likely to be in close proximity with these animals? These could be farmers, people who live within or in close proximity with rainforests, people working in arbatoires, cattle herders, bush hunters, park rangers, zoo keepers the list is endless. Apart from people who live in close proximity with animals, let us consider also those that consume meat and meat products.

As outlined above apart from experts from the health and veterinary, it is important to involve the community if efforts to control zoonoses have to succeed. How?

Step1:

Through surveillance of food sources in the villages and communities, this includes where they slaughter both their wild and domesticated animals, where they hunt, and most important to test the meat for diseases before it is consumed. In most developing countries, there are communities that are either isolated or have no facilities and or expertise to monitor and or test the meat for diseases. This is an important step as this could be a crucial step in controlling some of the zoonoses.

 Step2:

Knowledge and understanding of their eating and food storage habits, how does the community prepare their meat products, do they eat the meat raw, how do they handle the meat after slaughter?

This step is crucial in understanding where the source of the disease as well as it can be used as a screening process for what could be the zoonoses that can survive in the various methods of food processing used in the community and or village. For example if they consume the meat raw, then we start looking at zoonoses that are spread through animal blood, those that survive as cysts in the animal flesh, those present in the bowels and animal excreta and so on.

Step 3:

Sanitation, which includes disposal of animal remains, proximity of people to their livestock, management of livestock and exposure to animal excreta (in case of leptospirosis) is also another important factor to consider if we can control zoonoses. This point puts emphasis on the fact that an infected animal carcass or any animal remains are still a source of zoonoses. Poor disposal can lead to spread of diseases.

From these three steps outlined it is crucial to have community involvement much earlier even before the onslaught of the diseases. If through surveillance, there is knowledge of the possible zoonoses that could affect a particular community, it is importantl to alert the community before hand and offer the necessary training and advice to avoid the spread of the diseases. Knowledge of day to day habits of a community can be a good start in communicating to the community of the lurking dangers with regard to animals and their products. Community leaders have a good connection as regards communication and execution of instructions within their communities. These leaders are therefore an important link between health/veterinary experts and the entire community. It is important to understand hierarchies within the communities as this is a crucial aspect in communicating with communities especially in rural areas.

Zoonoses and Man; Where can we find zoonotic diseases?

Human beings have always lived in close proximity with animals for centuries. Animals have been used as beasts of burdens on farms and households as well as a source of meat and animal products such as milk, eggs, meat and leather. Animal excreta has been used as a source of manure and biogas.

In as much as animals have always provided for man, they have also been a source of some of mans’ worst diseases some of which are curable and others incurable.

The diseases that are carried by animals and are passed on to humans are called zoonosis(es). Some of the modern diseases that started as zoonoses include:

·         Measles

·         Smallpox

·         Influenza

·         HIV

·         Diptheria

In my previous entry, I outlined zoonotic diseases by their causative agents and you will notice that the 5 diseases I have mentioned above including SARS, rabies, echirococcosis, taeniasis, brucellosis and trematodisis, are the major diseases that are of focus as public health threats.  But there are many more zoonotic diseases the world is not paying attention to and yet they are causing death  and becoming a public health issue. As such most zoonotic diseases are also known as neglected tropical diseases (NTDs).

Where are these zoonotic diseases found?

From the name neglected tropical diseases one could have a clue that these diseases mostly occur in the tropics. They are commonly found in Latin America, South East Asia and part of the Congo basin.

Below is the list of countries where NTDs are a major problem;

Americas and Latin America	South East Asia	Africa
Mexico	India	Cameroon
Colombia	Vietnam	Tanzania
Ecuador	Laos	Congo- DRC
Peru	Bangladesh	Uganda
Bolivia	Cambodia
Peru	Thailand
Brazil	Malaysia
Venenzuela
USA

Outbreaks of zoonotic diseases have occurred in different parts of the world but the countries mentioned above have experienced some of the major outbreaks or have frequent outbreaks of zoonoses.

It is interesting to note that the countries that are mentioned in the table above have something in common, close proximity to rainforests. Is there any association between zoonoses and proximity to rainforests? From the map (

www.healthmap.org/predict/) I noticed that most of the zoonotic oubreaks occured in countries where there is a rainforest. In Africa, the Congo basin host the second largest rainforest in the world, the Congo rainforest, which encompasses, Cameroon, Congo-DRC and Equatorial guinea. While in Latin America, the countries affected by zoonoses host the worlds largest rainforest, the Amazon rainforest. In South East Asia, Malaysia and Indonesia also have some raiforests.

 

One important thing to note is that the rainforests of Africa, South East Asia and its associated archipelagos, and tropical America they match in their animal and plant diversity.

 

So what are the animals that are shared bewteen these rainforests which could be major carriers of zoonotic diseases?

 

Below is a list of animals associated with zoonotic diseases, I beleive one will be able to pack out some animals that are associated with rainforests.

 

Higher Mammals	Other mammals	Birds	Others
Cattle	Bats	Geese	Ticks
Chimpanzees	Hamsters	Chickens	Snails
Humans	Hyraxes		Mosquitoes
Gorillas	Oppossum		Fleas
Monkeys	Rabbits and hares		Flies
Dogs	Raccoons		Lice
Cats	Rats		Assasin bugs
Horses
Pigs
Sheep
Sloth
Wolves

In my next entry I will discuss further some of the major zoonotic outbreaks in the world and what is being done to control this emerging public health issue.

References

www.healthmap.org/predict/