Global tuberculosis research and its future prospects

Abstract

Tuberculosis is the infectious disease that causes the most deaths each year in the world. Around 25% of the population is estimated to be infected with, Mycobacterium tuberculosis, the bacteria that gives rise to the disease, and more than one and a half million people die each year from this cause. A rigorous bibliometric analysis has been developed around tuberculosis disease, and the most remarkable results are presented in this paper. It is observed that interest in tuberculosis is growing, and the control of its spread has become one of the main health priorities in the world, with the United States, the United Kingdom, and India, leading the research in this area. On the other hand, it has been observed that there are two main health concerns around the tuberculosis: drug-resistant tuberculosis and co-infection with HIV. Finally, conclusions are offered, playing a frontline role in science policy decisions and research performance evaluations.

Introduction

Tuberculosis (TB) accounts for a significant global burden of disease and substantial investment in research and development. Although it is an ancient and curable disease, TB remains the world's leading cause of death from an infectious agent, exceeding human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) for the first time [1,2]. More than 1.7 billion people (about 25% of the world population) are estimated to be infected with Mycobacterium tuberculosis [3]. According to the World Health Organization (WHO), in 2017, 10 million individuals became ill with TB and 1.6 million died, including 0.3 million among people with HIV [3].

One-third of the new cases (about three million) remain unknown to the health system, and many of them are not receiving proper treatment. The TB occurs in every part of the world. In 2017, the largest number of new TB cases occurred in the South-East Asia and Western Pacific regions, with 62% of new cases, followed by the African region, with 25% of new cases [4].

Poverty, HIV, and drug resistance are major contributors to the global TB epidemic [5]. Almost of TB cases occur in developing countries (95%). The global incidence of TB peaked around 2003 and appears to be declining, with a deceleration of around 2% per year [6]. Ending the TB epidemic by 2030 is among the health targets of the newly adopted Sustainable Development Goals. WHO has gone one-step further and set a 2035 target of 95% reduction in deaths and a 90% decline in TB incidence – similar to current levels in low TB incidence countries today.

In the last years, important progress has been made for better control of the disease. While microscopy and culture continue to be crucial for diagnosis of TB, molecular diagnostic tests provide more timely results improving quality of care and patient safety [7]. The range of molecular diagnostic tests to aid in the diagnosis, including the nucleic acid amplification test and whole-genome sequencing (WGS), has expanded tremendously [8]. They are becoming more accessible not only for detection and identification of Mycobacterium tuberculosis complex (MTC) in clinical specimens, but now extend to the diagnosis of drug-resistant strains [9].

Although small changes have been made in the treatment of drug-susceptible TB, the recent emergence of drug-resistant TB has become a serious concern increases the cost and duration of treatment, while decreasing the efficacy. Data on increased effectiveness with new and repurposed tuberculosis drugs (delamanid, bedaquiline, pretomanid, clofazimine, carbapenems, and linezolid) have led WHO to recommend all-oral therapy for drug-resistant tuberculosis [10]. Studies have shown that new shorter regimens for latent tuberculosis treatment containing rifampicin or rifapentine are as effective as longer, isoniazid-based regimens [11,12]. By the other hand, there is a promising TB vaccine candidate to prevent the progression of infection to the disease. However, new tools alone are not sufficient [13].

The main purpose of this paper is to bring-out a bibliometric analysis of the most current advances published in scientific journals about the human TB. This systematic mapping study, despite the possible limitations of this type of indicator, plays a first-line role in scientific policy decisions and in evaluations of research performance. To address this bibliometric analysis, different items have been studied and analyzed in depth. These are: the progression of scientific production; the distribution of publications by countries and institutions; the main authors; and the most relevant keywords of these publications.