History of filariasis

Lymphatic filariasis is a neglected tropical disease caused by infection with the mosquito-borne, thread-like, parasitic filarial worms Wuchereria bancrofti, Brugia malayi and B. timori.

In Egypt, nocturnally periodic bancroftian filariasis has been endemic since Pharaonic times. The first written documents of filariasis come from the ancient Greek and Roman writers who could differentiate between the similar symptoms of leprosy and filariasis.

Jan Huygen Linschoten during his trip to Goa between 1588 and 1592 first documented the disease symptoms and wrote that inhabitants ‘‘all born with one of their legs and one foot from the knee downwards as thick as an elephant’s leg.’’

Filariasis was the first human disease described in which transmission through the skin was cause by the bites of arthropods. Doctor O. Wucherer (1868) found the embryonic filarial worms in the urine of a patient in Bahia, Brazil. T. R. Lewis (1872), working in India, observed the embryos in the urine and also in the blood, and Joseph Bancroft (1878) in Brisbane, Australia first described the adult worm. The parasite has been designated Wuchereria bancrofti.

The momentous discovery of the role of the mosquito in transmitting the disease was made by the Scotsman Patrick Mansion (1877) while he was practicing medicine in the Far East with the Chinese Imperial Maritime Customs. He became interested in the disease that confronted him, including filariasis. In that disease he recognized the parasites in peripheral blood films and also in postmortems material.

Patrick Mansion noted the nocturnal appearance of the parasites in the peripheral blood and postulated that a blood sucking insect might be responsible for transmitting the infection. Manson proved the presence of the microfilaria in the mosquito Culex fatigans, thus supplying the missing link in the life cycle of the disease.
History of filariasis

Virus infection disease: Rabies

Infectious Disease - Rabies
At the end of the nineteenth century, hundreds of people died from rabies every year. Almost invariably, these people got the disease from the bite of a domestic animal, usually a dog.

Because of the efforts of Louis Pasteur and many others, it is rare today for some one to die from rabies. And the few cases of rabies that arise each year almost invariably come about as a result of a bite from a wild animal, like a skunk or a bat. The rarity of the disease and the elimination of rabies from domestic animals are due largely to Pasteur’s discoveries and intense vaccination programs.

But rabies remains as a glaring example of the pain and suffering that can follow infection. And rabies is only one example of thousands of infectious diseases – diseases caused by prions, viruses, bacteria, fungi, and parasites – that make us sick and kill us. Some infectious may be essential. Others are terrifying.

A rhabdovirus virus causes rabies. There are many different types of rhabdoviruses and they cause a whole range of disease – rabies is one of the worst. The rabies is bullet shaped, covered with a large sheet of host-cell membrane and fortunately for all of us, is easily destroyed by soaps or drying. Rabies viruses are about 75 nm (nanometers) in diameter and about 150 to 300 nm long. A nanometer is one billionth of a meter, far beyond the realm human vision. These are tiny packets of trouble.

Rabid animals transmit rabies in their saliva. From the bite wound, the virus makes its way into neurons. Then it travels along the neurons to the central nervous system (brain and spinal cord) where it sets up shop. In the central nervous system, the rabies virus begins to destroy neurons as it produces more virus. Some of the new virus particles travel to the salivary gland, where they help spread the disease to others through bites.

In the process of its self-replication, the rabies virus decimates many of the neurons in the central nervous system. The result is a mental meltdown. But the virus doesn’t destroy all of the brain – just enough to drive the dog mad, just enough to make dog want to bite every other living thing it sees and pass on the infection.
Virus infection disease: Rabies

Zika virus

Zika virus, a single stranded RNA virus is an unassigned member of the Flavivirus genus of the Flaviviridae family. It is most closely related to Spondweni, Uganda S and yellow fever viruses. The virus is responsible for cases of fever, rash and arthralgia.

Zika virus was first described in 1947 in rhesus monkey serum in Zika Forest, near Entebbe in Uganda. In 1948 it was first isolation from a mosquito (Aedes africanus) and in 1968 from humans in Nigeria.

In Burkina Faso, Zika virus has been identified in the following mosquito species: Aedes aegypti, Aedes furcifer, Aedes jamoti, Aedes opok and Aedes luteocephalus.

Zika virus is stable for up to 6 months at 4 C in glycerol, but is easily inactivated by chloroform, ether and sodium deoxycholate. The virus is also inactivated by p-chloromercuribenzoate.

The virus has been linked to microcephaly in Brazil, where there have been nearly 4,000 cases of suspected microcephaly and 1.5 million cases of the Zika virus, prompting the World Health Organisation to declare an international emergency.

Microcephaly is a serious birth defect, characterized by an abnormally small head and brain. Common symptoms of the Zika virus include fever, rash, joint pain and conjunctivitis, according to the CDC. Approximately one in five people infected with the virus show symptoms.
Zika virus 

Leprosy

Leprosy, a chronic bacterial infection (also called Hansen’s disease) caused by Mycobacterium leprae that damages nerves in the skin, limbs, face and mucous membranes. Untreated leprosy can lead to severe complications, including blindness, and disfigurement, but leprosy can be cure with proper medication.

The modern term for the disease is named after the discoverer of the bacterium, Gerhard Armauer Hansen. Sufferers of Hansen’s disease have historically been known as lepers, however this term is falling into disuse as a result of the diminishing number of leprosy patients and the pejorative connotations of the term.

Contrary to popular belief, it is not highly contagious. While the disease still carries significant stigma, patient care has become integrated with routine health care.

Like tuberculosis, it is a very old disease which was already known in ancient times. Leprosy was first mentioned as a curse in Shinto prayers of 1250 BC. It was also mentioned in some Egyptian legends to explain the exodus of the Hebrews. For hundreds years, those with leprosy were taken to a priest, not a doctor and were found ‘guilty; not sick.

Outbreaks of the disease increase in poor socioeconomic conditions (lack of nutrition, bad physical constitution, insufficient hygienic measures). Leprosy primarily involves the skin and the peripheral nervous systems. Typical symptoms are a loss of hair, and impairment of sweet production and sensory disorders.
Leprosy

Short History of Tuberculosis

Short History of Tuberculosis
In the Paleolithic period, people lived as wanderers, did not settle in villages or permanent locations, and do not congregate in large groups.

While tuberculosis may have occurred sporadically, it an other infections disease probably did not occur in epidemic form.

Beginning in about 8000 BC, humans developed primitive agricultural techniques that allowed settlement in permanent sites and with this development came the domestication of cattle, swine and sheep.

In all probability, tuberculosis occurred more frequently in this setting, but it nevertheless remained rare.

Tuberculosis probably occurred as an endemic disease among animals long before it affected humans. Mycobacterium bovis was the most likely infecting organism and the first human infections may have been with Mycobacterium bovis.

Since Mycobacterium tuberculosis infects all primate species, it is also possible that this species existed in subhuman primates before it became established in humans.

Tuberculosis probably occurred as a sporadic and unimportant disease of humans in their early history. Epidemic spread began slowly with increasing population density.

This spread and the selective pressure it has exerted have occurred at different times around the globe.

The epidemic slowly spread worldwide as a result of infected European travelling to and colonizing distant sites.

In the 1700s and early 1800s tuberculosis prevalence peaked in Western Europe and the United States and was undoubtedly the largest cause of death.

100 to 200 years later it had spread in full force to Eastern Europe, Asia, Africa and South America.

1.6 millions death worldwide due to tuberculosis in year 2002 alone. Currently tuberculosis kills 1.8 million people each year. However scientist believed that can be averted by 2050 with better testing, drugs and vaccines.

Treatment from 1995 to 2008 saved six millions lives. However 36 millions infected with tuberculosis during 1995-2008 were cured and incidence of the lung wasting disease has begun to regress, but only by about one percent per year.
Short History of Tuberculosis

A Historical Perspective of Dengue

A historical Perspective of Dengue
The story of dengue in many ways starts in the Americas.

Dr. Benjamin Rush made the first good clinical description of dengue.

He was in charge of hospitals under General George Washington in the Oriental Army and described for dengue outbreak in Philadelphia in 1780:

“This fever generally came on with rigor, but seldom with a regularly chilly fit. The pains which accompanied this fever were exquisitely severe in the head, back and limbs.

The pains in the head were sometimes in the back parts of it, and at other times they occupied only the eyeballs.

A few complained of their flesh being sore to the touch, in very part of the body. Its general name among all classes of people was the break-bone fever.”

Dengue today presents with the same fever, headache, eye pain, myalgia and arthralgia.

The US military’s dengue research efforts started just after the Spanish-America War, sparked by the very many dengue causalities in the Philippines.

A dengue commission was established in 1900, and Ashburn and Craig were sent to the Philippines to determine the etiology of dengue and to devise countermeasures.

Although a series of experiments they deduced that dengue was caused by “an ultra microscopic and non-filterable agent,” or a virus.

Ashburn and Craig confirmed that virus could be transmitted from person to person by both mosquito and by syringe; they made careful description of the disease to include leucopenia.

Important for vaccine development, they demonstrated that immunity following infection was absolute; they could only make healthy volunteers with dengue one time.

During World War II, Japan and the United States of America had large dengue research programs.

Dr. Hotta and Dr. Kimura in Japan isolated the dengue serotype 1 virus (DENV-1) shortly before Dr. Sabin and Dr. Schlesinger did so in Hawaii.

In the 1950s, the face of dengue changed dramatically with the widespread recognition of DHF. The army and the Air Force sent Dr. Bill Hammond to investigate the 1956 outbreak of hemorrhagic fever in the Philippines.

He worked with Philippines and Thai scientist to isolate DENV-3 and DENV-4.

The most important pathological process that distinguished DHF from dengue is plasma leakages that can lead to shock and death.

Untreated, DHF has a mortality rate of around 10%. With careful fluid management, however, mortality rates drop to below 1%.

DHF can occur in any age group, but it is most common among children living in dengue hyperendemic areas.
A historical Perspective of Dengue

Anthrax: The Disease and the History

Anthrax: The Disease and the History
Anthrax is a peracute, acute or sub-acute disease primarily affecting herbivores but also encountered in other mammals, including humans, and occasionally birds.

The words ‘anthrax’ is derived from the Greek anthrakos, meaning coal, referring o the characteristics eschar in the human cutaneous form of the disease.

The familiar name ‘black bane’ and the French and Italian names for the disease charbon and carbonchio, similarly reflect this manifestation.

Names in other languages and older English names refer to other of its significant manifestations or to its sources of infection, viz Milzbrand (German) and miltvuur (Duth), meaning ‘spleen fire’, pustula maligna (Spanish), Bradford disease, woolsorter’s disease, ragpicker’s disease and so on.
Its numerous synonyms in many national languages and local dialects reflect the historical familiarity with the different syndromes before it was realized that they were manifestations of one etiological agent, Bacillus anthracis.

Fifth and sixth plaques of Egypt in the time of Moses are thought by some to have represented the earliest historical; reports of the anthrax due to respectively to systemic and cutaneous forms of the disease.

Anthrax appears to have featured in Asia Minor at the time of Siege of Troy (ca. 1200 BC) an description of the typical symptoms in the writing of Homer (ca. 1000 BC), Hippocrates (ca. 400 BC), Varro (116 – 27 BC), Virgil (70 – 19 BC and Galen (ca. 200 AD) indicate that the Greeks and Romans were well acquainted with it.

Scientifically reports began with the descriptions of malignant pustule and the disease in animals in 1700s.

The nineteenth century saw anthrax as the first disease of man and animals shown to be caused by a microorganism and as the disease on which much of the original work on bacteria and vaccines was done.
Anthrax: The Disease and the History

Influenza – Major Occasional Pandemic Outbreaks

Influenza – Major Occasional Pandemic Outbreaks
Influenza or simply “flu” is caused by a virus. It occurs not only in occasionally major pandemic outbreaks, but also in epidemics of variable severity almost every winter.

The term “influenza” has been derived from the Italian ‘influentia’ in the mid-1300s, indicating that, at the time, the illness was believed to result from astrological influences.

Yet, the aetiloogy of the disease and the explanation for its peculiar behavior remained elusive.

At the turn of the 19th century, influenza was thought to be due to a bacteria infection with Haemophilus influenzae.

It was not until 1931 that Richard Shope showed that swine influenza could be transmitted with filtered mucus, indicating that the causative agent was a virus.

A few years later, Smith and co-workers isolated the influenza virus from humans with respiratory illness.

The burden of influenza for the society, not only from a clinical but also from an economic perspective, is often underestimated.

This relates particularly to the recurring annual winter epidemics. Fortunately, since the virus was first discovered, efficient means to contain the infection have been developed.

Vaccination is the cornerstone of influenza prevention and control. Accordingly, the WHO (World Health Organization) has issued guidelines for implementation of influenza vaccination programs in individual countries.

Yet, in many places, implementation of vaccination programs remains woefully deficient. This implies that significant numbers of people at risk of the complications of influenza remain vulnerable to infection and possibly death.
Influenza – Major Occasional Pandemic Outbreaks

History of Influenza

History of Influenza
Hippocrates recorded an epidemic of a flu-like infection in 412 B.C that wiped out the Athenian army.

The sixteenth century saw two flu pandemics that spread throughout Europe. The first, in 1510, infected nearly the entire population of Europe, but claimed few lives.

The second, in 1580, devastated cities and spread through the whole of Western Europe. The city of Rome, for example, had 9,000 fatalities.

At least pandemics of flu spread throughout Europe in the seventeenth century. In the past of 200 years eight great flu pandemics seized the world prior to the devastation wrought by the 1918 flu.

During a period of fourteen months beginning in the spring of 1918, half of the entire world’s population was infected with the influenza virus and nearly 41 million people died.

Every country in the world was affected, no matter how remote, and this occurred in an era before air travel and a global community existed.

Victims who died during the 1918 flu were typically healthy young adults. Among the 20 to 40 year old age group, the fatality rate from the 1918 flu was 50 percent.

The virus of 1918 was so effective at killing its host that within a short period of time it rendered itself extinct, people either immune to the virus or dead.

Since that time several other lesser pandemics have occurred across the globe, but health officials anxiously await the next deadly flu pandemic, which they predict as inevitable.

When it occurs, experts foresee millions of death, hospitals quickly flooded with cases of pneumonia, and every health care system in the world over whelmed by the volume of flu victims.
History of Influenza