In Part 2 of this special, we investigate more diseases the world has more or less neglected, one of which infects up to 1 in 3 individuals in the world.

6. Buruli Ulcer

This disease is caused by the Mycobacterium ulcerans bacterium, of which transmission mechanisms are currently still poorly understood. This has greatly hampered preventive control efforts, so current efforts mainly focus on minimising the suffering, disabilities, and socioeconomic burdens of those diagnosed.

This disease, unlike many others, can actually be easily cured with a cocktail of antibiotics in up to 80% of all cases. However, timely detection is key, and can be a challenge as symptoms often kick off as a painless swelling, ignored by many.

Of the 33 countries known to prevalently contain this bacteria, 12 have reported 2,200 new cases, mostly in children under 15 years of age. Since 2010, the number of cases has actually declined overall, but in Australia numbers have instead been rising.

7. Yaws

Yaws is caused by Treponema pallidum subspecies pertenue, which is closely related genetically to the causative agent of syphilis. It affects the skins, bones, and cartilage and is a chronic, disfiguring childhood infectious disease. The symptoms show up weeks to months after the first infection, and can also include yellow lesions and bone swelling.

Humans are believed to be the only reservoir of this bacteria, with it being transmitted from person to person. It is cured by a single oral dose of the inexpensive antibiotic azithromycin.

Those most affected by the disease often have limited access to basic social amenities and health care. This is further exacerbated by poor environmental conditions, lack of basic toiletries and clothing, as well as overcrowding that facilitates spreading.

From the period of 2010 to 2013, more than 250,000 cases have been reported.

8. Soil-Transmitted Helminth

Soil-transmitted helminth infections are amongst the most common infections in the world, shockingly accounting for approximately 2 billion infections at any one time - one in every three individuals.

They are transmitted by hookworm eggs, facilitated by a lack of proper sanitation facilities and the contamination of soil used to grow crops. The severity of this infection is proportional to the number of worms inside the individual.

Those with light infections often do not exhibit any symptoms. Serious infections can cause diarrhoea and abdominal pain, general malaise and weakness, as well as impaired cognitive and physical development.

In very serious cases though, chronic intestinal blood loss is seen that can result in anaemia – if uncontrolled, death results.

The WHO recommends medications albendazole (400 mg) and mebendazole (500 mg) as medications that are effective, inexpensive and easy to administer.

9. Taeniasis

Caused by the beef tapeworm, taeniasis is an intestinal infection that can be contracted by the consumption of raw or undercooked infected pork or beef. These worms have been known to grow up to 10 metres long inside the human body.

In mild cases, this can cause abdominal pain, nausea, diarrhoea or constipation. However, in serious cases (such as the case of the 10m long tapeworm) and when the tapeworms travel to the brain, neurocysticercosis can result in epileptic seizures (accounting for about 30% in endemic areas), which can be fatal.

Medication is the recommended treatment, however healthcare providers in rural regions face more debilitating issues in treating individuals with neurocysticercosis - As the destruction of cysts could lead to an inflammatory response, treatment must often be tailored to the individual on a case-by-case basis.

Despite being very prevalent across the globe, taeniasis is heavily underreported, especially in areas with limited access to health service. As such, treatment and efforts to eradicate are often hampered. This parasite does not only affect one’s physiology; it renders affected beef and pork unsaleable, and reduced the income of cattle farmers.

Due to its widespread nature, the WHO has estimated that this is a significant source of morbidity, with an estimated total of 2.8 million Disability Adjusted Life-Years (DALYs).

10. Guinea-Worm

The last disease of this series has an optimistic story: It is a crippling disease close to total eradication, with only 22 human cases reported in recent years, a marked decrease from the 3.5 million cases in the 1980s. This disease is transmitted when water infected with the larvae of the worm is consumed.

The Guinea-worm is the largest of all parasites affecting humans, with the female carrying about 3 million embryos. It migrates through the tissues and cause severe pain when passing through the joints. It then bores through the feet of hosts, causing an intensely painful oedema, a blister and an ulcer accompanied by fever, nausea and vomiting.

Despite its horrifying nature, an infection is rarely fatal, but can cause extreme discomfort for weeks. As such, it is with much relief that we report the numbers have gone down drastically in recent years due to better healthcare strategies and control. MIMS

Read more:
10 near-forgotten diseases that are still very real threats – Part 1
Top 8 bizarre medical stories of 2016
5 unexpected heart disease risk factors that patients must watch out for
A closer look at 4 of the rarest heart diseases