Scientists working with the International Centre for Diarrhoeal Disease Research, Bangladesh have developed a dipstick named Cholkit for rapid, early and effective diagnosis of cholera.
Following three years’ rigorous research and development process, the rapid diagnostic test, short RDT, was successfully evolved to meet the requirements of such tests fulfilling the guidelines.
The RDT is capable of detecting Vibrio Cholerae from stool.
Cholkit is an immunochromatographic test device called dipstick that is dipped into a tube with stool specimen and provides qualitative result (coloured band) readable by the naked eye within maximum time of 15 minutes.
A field evaluation of Cholkit has recently been published in the scientific journal PLOS Neglected Tropical Diseases.
It shows that the sensitivity and specificity of Cholkit is similar to commercially available rapid diagnostic tests, when used in field settings for detecting Vibrio Cholerae from stool specimens.
A total of 7,720 stool samples were tested during the evaluation that showed that Cholkit had 76 per cent of sensitivity and specificity of over 90 per cent while other rapid diagnostic test showed around 72 per cent and 86.8 per cent respectively.
The gold standard for detecting cholera is laboratory confirmation by stool culture, which is sensitive to several factors, including the quality of sampling, delays in shipment, laboratory equipment, skilled human resources, time (24 to 72 hours) and cost ($6 to $8 per sample).
From the public health perspective, the management of cholera outbreaks needs immediate detection as the pathogen has immense potential to spread and cause epidemics in a short period of time.
Thus, the need for simple and easy to use rapid diagnostic tests which are quickly interpretable, require simple storage facilities, and are reasonably priced is a clear choice.
The new kit have the potential to be used at the primary health care level for cholera surveillance, for early detection of outbreaks and as a tool for an initial alert for monitoring of seasonal peaks in highly endemic areas and in peripheral health care facilities.
According to ICDDR,B, cholera is an ancient disease. Globally, an estimated 1.3 billion people are at risk of this disease, with South Asia, taking the largest share.
In Bangladesh, at least 66 million people are at risk of cholera, with nearly 1,10,000 cases reported annually with many more mild and asymptomatic cases in the community.
The disease is primarily caused by a pathogen called Vibrio Cholerae, which has over 200 serotypes. The serogroup O1 and O139 have been reported to be pathogenic and cause cholera epidemics and pandemics.
However, in the last decade no epidemics due to Vibrio Cholerae O139 have been reported, only sporadic clinical cases have been observed.
Cholkit is found to be highly efficient in detecting Vibrio Cholerae serogroup O1 and has received official licensure, it is priced around $3.
Firdausi Qadri, a scientist at the Infectious Diseases Division of ICDDR,B led the development of Cholkit.
Firdausi Qadri said, ‘Historically, all the seven cholera pandemics originated from this part of the world.
She said that management of cholera outbreaks depends on early detection of cases.
Now, in addition to the laboratory culture of stool samples, imported rapid diagnostic test kits are being used for cholera detection, she added.
‘And, Bangladesh has locally-produced rapid diagnostic test Cholkit with the potential to reduce import dependency and the potential to create new avenues for export to other endemic countries in the future.
Thus, Bangladesh will have completed locally-produced cholera preventions tools - a vaccine and a rapid diagnostic test to combat this ancient disease,’ Firdausi said.
The Cholkit is now being used in 22 cholera sentinel surveillance sites across Bangladesh which are managed jointly by the ICDDR,B and the Institute of Epidemiology, Disease Control and Research.
Want stories like this in your inbox?
Sign up to exclusive daily email
More Stories from Adults’ health