Giant rats are probably not the first thing that come to mind to tackle tuberculosis but scientists hope their sniffing skills will speed up efforts to detect the deadly disease in major cities across the world.
Tuberculosis, which is curable and preventable, is one of the world’s deadliest infectious diseases, according to the World Health Organization (WHO), killing 1.7 million people in 2016 and infecting 10.4 million others.
African Giant Pouched Rats, trained by Belgian charity APOPO, are known for sniffing out landmines in countries from Angola to Cambodia and for detecting TB cases in East Africa.
Over the next few years, APOPO plans to fight tuberculosis at the source by launching TB-detection rat facilities in major cities of 30 high-risk countries including Vietnam, India and Nigeria.
“One of the best ways to fight TB at source is in major cities that draw a lot of people from the rural areas,” James Pursey, APOPO spokesman, told the Thomson Reuters Foundation.
“It is a vicious circle. You can be reinfected. To fight TB, you have to hit it hard,” he said by phone from Zimbabwe.
Many people get infected in big, densely populated cities and spread the disease to rural areas, according to Pursey.
The rats learn to recognize the presence of TB in samples of mucus that is coughed up from the patient’s lower airways.
In Tanzania, people in communities where TB is most common, including in prisons, often fail to show up for screening because of a lack of money or awareness, placing a huge burden on health authorities, health experts said.
“TB is a disease of poverty,” said Pursey. “If nothing changes it can only get worse.”
The APOPO has seen the TB detection rate increase by 40 percent in clinics it has worked with in Tanzania and Mozambique, according to Pursey, who said that using rats to screen did not negate the need for proper diagnostic testing.
While a technician may take four days to detect a case of TB, a trained rat can screen 100 samples in 20 minutes, and a rat screening costs as little as 20 US cents, APOPO said.
Tuberculosis (TB) bacterium primarily affects the lungs, but can also spread and cause secondary infections to the uterus and even the fallopian tubes, which can reduce chances of pregnancy, health experts warned ahead of the World Tuberculosis Day that falls on March 24.
Usually caused by Mycobacterium tuberculosis (Mtb) bacteria, TB is the top infectious killer worldwide, claiming around 4,400 lives a day.
When the bacteria attacks the uterus, it causes uterine tuberculosis (also known as pelvic TB) which mostly affects women during the child-bearing period and is usually diagnosed during an infertility check-up.
“Women are more often affected than males and due to uterine tuberculosis, two out of 10 females are unable to bear a child,” Shweta Goswami, Infertility Specialist at Jaypee Hospital in Noida, told IANS.
“In extreme cases, the uterine lining become so thin that it is unable to bear an implantation resulting in miscarriage,” she added.
Mtb bacteria is transported by blood to other organs including reproductive organs and causes infection in fallopian tubes, uterus or in endometrial lining.
“Tuberculosis has the ability to severely damage the fallopian tubes, if not treated at the initial stage.. it can further lead to serious health complications and also result in infertility,” Goswami said.
Symptoms of TB in uterus include irregular menstruation, pelvic pain, continuous discharge which is stained with blood or without blood with a foul smell and bleeding after intercourse.
A 2018 study by the Indian Council of Medical Research (ICMR) showed that over 50 per cent of female patients in India coming for IVF procedure have been reported to have genital TB.
The prevalence of genital TB among Indian women has increased from 19 per cent in 2011 to 30 per cent in 2015.
In over 95 per cent of the cases, the infection was found to affect the fallopian tubes, in 50 per cent the endometrium and 30 per cent the ovaries.
Moreover, nearly 75 per cent of women with genital TB were found to be infertile, and 50-60 per cent of women with infertility were found to have genital TB, the report stated.
“Treating uterine TB should be of the utmost importance as soon as it is detected. There is social stigma attached with TB which makes it difficult for people to come openly and talk about it,” said Shobha Gupta, Medical Director and IVF Specialist from Mother’s Lap IVF Centre, New Delhi.
There are combined tests which are used to investigate whether a person is suffering from TB which are a combination of AFB smear, culture and PCR for tuberculosis.
“Also, with medication, women can be helped to conceive through ART, either IVF of or IUI, where intervention can be done to repair the after-effects,” Gupta noted.
According to the World Health Organization’s (WHO) ‘Global Tuberculosis Report 2018’, India accounted for 27 per cent of the 10 million people, who had developed TB in 2017, besides making up 32 per cent of global TB deaths among HIV-negative people and 27 per cent of combined TB deaths.
To combat the disease, it is essential that diagnostic facilities reach the farthest areas and people made aware of the consequences of contracting TB, said Rajkumar, Consultant Internal Medicine at New Delhi-based Indian Spinal Injuries Centre.
“It is also important that people thwart the factors that contribute to TB by making their living conditions more hygienic, improving immunity, and having better access to nutrition,” he added. (IANS)