Tag: tuberculosis

High Burden of Uncontrolled Disease in KwaZulu-Natal

Photo by Hush Naidoo on Unsplash

A comprehensive health-screening program has found a high burden of poorly controlled or uncontrolled disease KwaZulu-Natal, along with a high incidence of undiagnosed diseases.

The study, published in The Lancet Global Health, found that four out of five women over 30 had a chronic health condition, and that the HIV-negative population and older people had the highest burden of undiagnosed or poorly controlled non-communicable diseases such as diabetes and hypertension. The study was conducted at the Africa Health Research Institute (AHRI).

Study co-leader Emily Wong, MD, at AHRI in Durban, said: “The data will give AHRI researchers and the Department of Health critical indicators for where the most urgent interventions are needed,” Dr Wong said. “The research was done before COVID, but it has highlighted the urgency of diagnosing and treating people with non-communicable diseases — given that people with uncontrolled diabetes and hypertension are at higher risk of getting very ill with COVID.” 

HIV-associated tuberculosis infections are particularly prevalent in Durban. Dr Wong of the University of Alabama works there to understand the impact of HIV infection on tuberculosis pathogenesis, immunity and epidemiology. In sub-Saharan Africa, 15 years of intense public health efforts that increased access to antiretroviral therapy has resulted in decreased AIDS mortality and raised life expectancy. As a result, there is an increasing priority to address other causes of disease, including tuberculosis and non-communicable diseases.

Over 18 months, health workers screened 17 118 people aged 15 years and older via mobile camps within 1 kilometre of each participant’s home in the uMkhanyakude district. They found high and overlapping burdens of HIV, tuberculosis, diabetes and hypertension among men and women.

While the HIV cases were largely well diagnosed and treated, some demographic groups  still had high rates of undiagnosed and untreated HIV, such as men in their 20s and 30s. In contrast, the majority of people with tuberculosis, diabetes or hypertension were either undiagnosed or not well controlled. Of particular concern was the high rates of undiagnosed and asymptomatic tuberculosis discovered, as it remains one of the leading causes of death in South Africa.

“Our findings suggest that the massive efforts of the past 15 years to test and treat for HIV have done very well for that one disease,” Dr Wong said. “But in that process, we may have neglected some of the other important diseases that are highly prevalent.”

The mobile camps screened for diabetes, high blood pressure, nutritional status (obesity and malnutrition), and tobacco and alcohol use, as well as HIV and tuberculosis. The tuberculosis screening component included high-quality digital chest X-rays and sputum tests for people who reported symptoms or had abnormal X-rays. Clinical information was combined with 20 years of population data from AHRI’s health and demographic surveillance research. Using a sophisticated data system combined with artificial intelligence to interpret the chest X-rays, AHRI’s clinical team examined the information in real time, referring people to the public health system as needed.

The study found that: 

  • Half of the participants had at least one active disease, and 12 percent had two or more diseases. Diabetes and hypertension incidences were 8.5 percent and 23 percent, respectively.
  • One-third of the people were living with HIV, but this was mostly well diagnosed and treated. A particularly high burden of HIV, high blood pressure and diabetes was seen in women.
  • For tuberculosis, 1.4 percent of the people had active disease, and 22 percent had lifetime disease. About 80 percent of the undiagnosed tuberculosis was asymptomatic, with higher rates of active tuberculosis seen in men.
  • Several disease patterns varied by geographical location — eg, the highest HIV burden was seen near main roads, while higher rates of tuberculosis and non-communicable diseases were seen in more remote areas.

Source: University of Alabama at Birmingham

Journal information: Wong, E. B., et al. (2021) Convergence of infectious and non-communicable disease epidemics in rural South Africa: a cross-sectional, population-based multimorbidity study. The Lancet Global Health. doi.org/10.1016/S2214-109X(21)00176-5.

New Way to Compare Effectiveness of Tuberculosis Treatments

E. Coli bacteria. Image by CDC

A new study published in Nature Communications provides an important new basis for comparing the varying effectiveness of tuberculosis treatments.

Tuberculosis is a ancient disease caused by the bacterium Mycobacterium tuberculosis (Mtb) and aside from the COVID pandemic, is still the leading infectious cause of death globally, killing 1.2 million people each year. The availability of a new way to evaluate treatments can save lives.

In the study, the researchers aimed to provide a new perspective on assessing the effectiveness of tuberculosis drugs.

“A key roadblock that holds back new tuberculosis treatments is our current inability to accurately measure how effectively different treatments shorten the time needed to cure tuberculosis,” said lead author Nicholas Walter, MD, Ph.D., associate professor at the University of Colorado Anschutz Medical Campus. “Without improved tools to measure and compare the effectiveness of drug treatments, the evaluation and roll-out of new combination drug treatments will continue to proceed slowly.”

“In the past, the effectiveness of tuberculosis treatment has been judged by estimating the burden of the pathogen M. tuberculosis as enumerated via culture based approaches. This historical method correlates poorly with what we care about most, which is whether tuberculosis patients are durably cured,” added co-first author Gregory Robertson, PhD, assistant professor at Colorado State University.

By Vossman - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6865434
Structure and shape of the E.coli 70S ribosome. The large 50S ribosomal subunit (red) and small 30S ribosomal subunit (blue) are shown with a 200 Ångstrom (20 nm) scale bar.

The researchers measured the extent to which drugs interrupt the synthesis of ribosomal RNA, which is needed for the protein-making machinery of the bacterium. They found that drugs and drug regimens that treat tuberculosis faster inhibit Mtb rRNA synthesis more than less potent drugs and regimens. Their resulting new measure, called the rRNA synthesis (RS) Ratio is a useful molecular metric of drug activity based on a key microbial physiologic property rather than a simple measure of reducing bacterial burden.

“The RS Ratio gives us a readout of drug effect that opens a new era in understanding antibiotics. Measuring a key physiologic property of pathogens provides an innovative way of thinking beyond conventional measures of bacterial burden,” said senior author Martin Voskuil, PhD, associate professor at the University of Colorado Anschutz Medical Campus.

“The RS Ratio can enable more intelligent design and evaluation of candidate drug combination regimens, accelerating the development of treatments that can cure tuberculosis faster. This has crucial implications for combatting the global tuberculosis epidemic,” addrf co-author Payam Nahid, MD, MPH, professor and director of the University of California San Francisco Center for Tuberculosis.

Source: Medical Xpress

TB Vaccine Shown to Protect Against Common Infections

The tuberculosis (TB) vaccine Bacillus Calmette-Guerin (BCG) could protect newborns against a variety of common infections, such as upper respiratory tract infections, chest infections, and diarrhoea, according to a new study from the London School of Hygiene and Tropical Medicine (LSHTM).

It has been known that BCG protects against diseases other than TB, offering protection against non-tuberculous mycobacteria infection like leprosy and Buruli ulcer. It is also used in the treatment of superficial carcinoma of the bladder.

However, this is the first research to rigorously investigate the full range. The results suggest that vaccinating all babies with BCG on their day of birth could save lives by reducing neonatal infections in areas with high rates of infectious disease.

The study involved a randomised control trial of 560 newborns in Uganda, who were monitored for a range of illnesses. After six weeks, infection rates from any disease were 25% lower in the group that received the vaccine at birth, compared to the group that had not yet received the vaccination. The most protected appeared to be vulnerable groups such as low birth weight babies, and boys. Importantly, BCG appeared to protect against even severe infections.

Sarah Prentice, the lead author from LSHTM, said: “Nearly a million babies die every year of common infections so we urgently need better ways to protect them. Our research suggests that ensuring that BCG is given at birth could make a big difference in low-income countries, potentially saving many lives.”

The newborns were randomly assigned to receive BCG either at birth or at six weeks of age. They were followed-up by doctors, blinded to the intervention, for 10 weeks, who looked for any type of illness or infection.

The research team then compared how often infants in the two groups presented to doctors with infections of any kind, except TB, to see whether having BCG made a difference. They also took blood samples from both groups, to look at differences in their innate immune system, the body’s first line of defense against infections.

Infants vaccinated with BCG at birth presented to doctors with any kind of infection 25% less often than infants who had not. BCG seemed to protect against all kinds of infections, such as common colds, chest infections, and skin infections.

After the delayed group had been vaccinated, the rates of infection were identical between the two groups: the delayed group’s immunity ‘brought up to speed’ when they received BCG.

Study co-author Prof Hazel Dockrell, LSHTM, said: “It’s very exciting to think that BCG vaccination might help keep newborns safe against other dangerous infections, in addition to providing protection against TB. Although BCG is recommended at birth in many countries, it is often delayed due to logistical difficulties. Ensuring that the vaccine is given on day one, in areas with high rates of infectious disease, could have a major impact on infections and deaths in the newborn period.”

Though the study could not definitely determine whether the BCG vaccine was responsible for the lowered rate of infections, there is nonetheless great interest in applying the vaccine as a protection for novel disease outbreaks, such as COVID or Ebola, before a specific vaccine can be developed.

Dr Prentice said, “Since the findings show that BCG seems to offer wider protection against a range of infections, our study also raises hopes it might be useful in protecting the general population against COVID-19 and future pandemics – though we will need to see the results of other, more specific studies to know for sure.”

Source: News-Medical.Net

Journal information: Prentice, S., et al. (2021) BCG-induced non-specific effects on heterologous infectious disease in Ugandan neonates: an investigator-blind randomised controlled trial. The Lancet Infectious Diseases. doi.org/10.1016/S1473-3099(20)30653-8.