Tuberculosis scientific parallel sessions
Posted by Daniela Pereira-Lengkeek on 3 November 2009 at 09:10
By Ochieng’ Ogodo
While tuberculosis (TB) is largely under control in developed countries, it is spreading fast in the developing world. It still haunts the poor in third world and health experts are now describing the advent of deadly drug-resistant strain spreading fast in the developing world as a time bomb.
It is for this reason that health experts at the Fifth European and Developing Countries Clinical Trials Partnership Forum in Arusha, Tanzania, October 12-14 emphasised quick diagnosis and treatment, development of effective vaccine and addressing the weak treatment systems.
Dr Videlias Nduba of the Kenya Medical Research Institute (KEMRI) and Centre for Disease Control (CDC) Research and Public Health Collaboration presented on preparation of a site for conduct of TB vaccine trials for adolescents in Western Kenya.
Aiming at 5000 adolescent recruits screening for TB using conventional methods of skin testing, sputum microscopy and chest radiography (x-rays), he said, this presented a suitable opportunity for future vaccines development.
The recruits, Nduba said, are followed up for a year and preliminary results show a high prevalence of TB among this population and the site is deemed suitable for future TB vaccines.
Dr Peter Onyango who was part of the KEMRI/CDC Research programme study in Kisumu targeting 5000 adolescents, both in-school and out-of-school, placed premium on innovative continuous demographic surveillance system in vaccines preparatory studies such as use of mobile field site facilities. Enrolled individuals in this study will be targeted for potential participation in future TB vaccine research since the age group of 12 to 18 has experienced an escalation of TB cases in many parts of Africa.
The study team deployed a mobile clinical team with equipment that includes x-ray and enrols subjects in villages of the region. A series of TB tests including x-rays are done on spot and those found with TB are treated and those without TB are followed up for longer periods.
Forging partnerships was also highlighted as crucial in the fight against TB. Speaking on research capacity in TB endemic countries, Dr Tony Hawkridge said it was important to forge partnerships in development and licensure of new or improved TB vaccines.
The Aeras-EDCTP partnership was given as an example of such partnerships and in the programmes funded under the Aeras-EDCTP partnership, a network of sites which can share information and expertise are being developed. In a project called TBVACSIN five African sites are already working together.
Current treatment of drug sensitive TB involves a combination of ethambutol (E), isoniazid (H), rifampicin (R), pyrazinamide (Z) in the first two months and a combination of R and H in the last 4 months. Prof. Andrew Nunn presented on a study where patients with tuberculosis were randomised to a 6 months control regimen (2EHRZ/4HR) and to a 4 months study regimen where moxifloxacin (M) replaces H in the initial and continuation phases of treatment and rifapentine (P) replaces R in the continuation phase of treatment only (2EMRZ/2P2M2), where the continuation phase PM is administered twice weekly. He said that this international multi-centre controlled clinical trial, referred to as RIFAQUIN because it evaluates high-dose rifapentine and the quinolone (M) in pulmonary tuberculosis is faced with other challenges like elongated periods for getting regulatory approval.
Dr Mugahid Elhassan also informed the Forum that clinicians treating patients with TB symptoms in Sudan should think of norcadiosis, especially when patients show poor response to treatment.
Presenting on a study aimed to determine the occurrence of Nocardia species among Sudanese patients presenting with TB symptoms, Dr Elhassan said in the past the pathogen had been isolated from patients who did not respond to TB treatment and suspected to have multi-TB drug resistance.
In the study of about 229 patient recruits on similarity between pulmonary tuberculosis and pulmonary nocardiasis, sputum microscopy and cultures were used to make diagnoses. Genotyping for Norcadia Africana was also introduced and the pathogen was isolated from ten patients.
These results showed considerable occurrence of norcardiosis among patients presenting with TB symptoms in the part of Sudan where the study was conducted. The similarity of symptoms between the two infections may be due to similar functional proteins.
In the magnitude of childhood tuberculosis in Kilimanjaro region, northern Tanzania: a retrospective study from regional TB program registry presentation, Dr Charles Mtabho said childhood TB was 13 percent of all TB cases in the region. Only 25 percent of these were diagnosed using sputum microscopy. Clinical diagnosis, he said, is common among children because the majority cannot produce sputum or clinicians cannot get sputum samples from the patients.
The study showed the importance of childhood TB and that more resources and attention are required in this area. This study, he told a session at the forum, was set out to establish the magnitude of childhood TB in the region and characterise treatment outcome parameters. Investigators reviewed TB registers to extract the data.
Future strategies
Prof. Carol Holm-Hansen spoke about the need for quicker point of care test like serological test to reduce diagnostic delays that escalate TB infections in a community.
The issue of importance of improving vaccination against TB so that the infectious pool is eliminated was also raised by Prof. Willem Hanekom. The case to balance the two issues of rapid testing and vaccination with proper use of available or improved drugs was stated by Prof. Martin Grobusch.
According to Dr Hulda Swai studies to improve compliance and researching HIV-TB co-infection are required. Veronique Penlap stressed the prospects of importance of HIV and TB programmes working together while Dr Martin Boeree supported the treatment trials as a priority area for conquering TB.
Combination of vaccine and TB treatment research instead of making one area a priority over the others was strongly vouched for by Prof. Richard Adegbola with Dr Shreemanta Parida agreeing that working in all the three areas was the most sensible approach as there is a lot that is unknown in both vaccine and treatment of TB.
Dr Gibson Kibiki said a lot of investments have been made in both vaccine and treatment. He advocated that TB diagnosis should be included in the investment equation.
Filed Under: Tuberculosis, Tuesday
