- 18 Oct 2020
Thousands of people in northwest China have been diagnosed with a highly-infectious bacterial disease caused by the bacterial genus, Brucella. Unlike coronavirus the discovery of this bacteria dates back to 1850s in Malta when a group of British medical officers serving on the island, after the Crimean War detected this rare disease in Maltese citizens. Today, as it stands, the bacteria has infected nearly 10000 people in China as confirmed by the Gansu Provincial CDC.Is this the next pandemic?
History of Brucellosis
Sir David Bruce credited for nomenclature of Brucellosis; Image Credits: SlideShare
The disease, we now know as Brucellosis was first diagnosed in Malta, an archipelago in the Central Mediterranean where it stayed for about two centuries and only in 2005, Malta officially became free of Brucella. One of the instrumental reasons behind failing to eradicate the infection sooner was a lack of educated public willing to help. Maltese citizens were staunch supporters of alineating a disease through prayers and so it was very difficult for the British men to enforce the control measures on the local residents.
As a result, over the decades, more and more Maltese were infected owing to the half-hearted efforts. The work of Dr Themistocles Zammit showed that infected goats transmitted brucellosis and that banning use of their milk would be effective but it was not until 1930 that pasteurization came into picture and small sterile containers were being used for the purpose. In Malta, failure to control rogue flocks and small flocks kept for family use led to an epidemic caused by the sale of cheeselets (small cheeses). Finally in 2005, nearly a century after Zammit's discovery, Malta declared themselves free of Brucellosis.
What is Brucellosis?
Image Credits: Labpedia
In a journal 'Pathogenesis and immune response in Brucella infection acquired by the respiratory route' by Mariana C. Ferrero et al., 2020, it says, "Brucellosis is an infectious disease caused by Gram-negative, facultative intracellular bacteria of the genus Brucella, that affects several species of domestic animals, wildlife and humans, with a significant impact on public health."
Brucellosis is one of the most common zoonotic diseases and mainly affects people dealing with livestock. Annually, around 500,000 new human cases are reported. It has a worldwide distribution, mainly affecting the Mediterranean countries, Central Asia, India, Arabic Peninsula, and Central and Latin America. Brucella sp. usually enters its hosts through the mucous and is principally an airborne disease. Outbreaks of human brucellosis linked to airborne transmission have been reported in slaughterhouses, laboratories producing Brucella vaccines, and rural areas although the disease has hardly been reported fatal.
Acute human disease is characterized by symptoms such as undulant fever, night sweats, Splenomegaly (enlarged spleen) , weight loss, Myalgia (muscle pain), Arthralgia (joint pain) and depression.
How did China remind us of the forgotten parasite?
The recent outbreak in China had been caused by “contaminated exhaust” from a factory in Lanzhou producing vaccines for animals, as was reported by the Chinese authorities.
From July to August, 2019, the Zhongmu Lanzhou factory in China was entrusted with the production of Brucella vaccines in animal use. However, medical records show that they have been using expired disinfectants and sanitizers and thus, not all bacteria were eradicated in the waste gas. The contaminated waste gas containing the bacteria seeped out into the air and was carried by the wind down to the Lanzhou Veterinary Research Institute, where the outbreak first hit.
In the months after the outbreak, provincial and municipal officials launched an investigation into the leak at the factory, according to the Lanzhou Health Commission. By January, authorities had revoked vaccine production licenses for the plant and withdrew product approval numbers for its two Brucellosis vaccines. A total of seven veterinary drug product approval numbers were also cancelled in the factory.
In February, the factory issued a public apology and said it had "severely punished" eight people who were determined as responsible for the incident. Nevertheless, the careless and reckless behaviour of Chinese organizations and the subsequent connivance of the respective government has again proved detrimental to the cause of the society.
Is this the bridge to another dreadful pandemic?
Human brucellosis can be easily acquired by air transmission and therefore Brucella can be considered a possible biological weapon. B. suis was the first agent weaponised by the United States. Researches carried out during the 1950s evidently show that 10 to 100 aerosolized organisms are enough to generate disease in humans. "The high infective capacity of Brucella when delivered in this manner, its ability to spread easily, and the chronic and debilitating nature of human disease has led to the Centers for Disease Control and Prevention and the National Institute of Allergy and Infectious Diseases to classify B. melitensis, B. abortus, and B. suis as Category B bioterrorism agents",says I.M. Alonso Paiva, the author of 'Microbes and Infection'.
In another article, "Human Brucellosis and Adverse Pregnancy Outcomes", Angela M. Arenas-Gamboa reviews Brucellosis as a reproductive disease in animals more than a flu-like infection in primates. She says, there is gleaning evidence to suggest that maternal infection poses a significant risk factor for adverse pregnancy outcomes including increased risk for miscarriage during the first and second trimester of gestation, preterm delivery, and vertical transmission to the fetus. Brucellosis during pregnancy, therefore should be considered a significant risk factor for adverse pregnancy outcomes in humans.
While history has seen sporadic outbreaks of Brucellosis, whether it will, i.e. if it all can take the shape of a pandemic is still under consideration. Unlike the current pandemic that has already grappled the world and has caused around a million deaths, Brucella sp. is not unknown to mankind, or in other words, it's not novel. Furthermore, vaccination for prevention and control of Brucellosis in animals is already available. In spite of all medical precautions being readily accessible, the World Health Organisation has issued a set of conditions in which epidemics may occur, such as distribution of incriminated produce, usually raw milk or cheese from an infected herd/flock. The best way to manage these sorts of infestations lies in the proper identification of the common vehicle of infection and subsequent prohibition of production and distribution unless pasteurization is introduced.
The age-old folklore says,'Prevention is better than cure' and so it is. While Brucellosis might not be an immediate cause of concern, a trifle precaution following the profundity of medical experts might be propitious in effacing the cause, before it becomes an effect.