Biomedical subjects

Mahesh K Puri

Publications and source records attributed to Mahesh K Puri.

5 recordsLinked to original sources

PubMed2006

Implementation of good clinical practice guidelines in vaccine trials in developing countries.

The practicalities when applying the ICH GCPs (International Conference on Harmonization 1996 Good Clinical Practices [EU, MHLW, FDA. International Conference on Harmonization Guideline for Good Clinical Practice; 1997] in less developed countries (ldcs) are seldom discussed and we found no guidelines as how to "adapt" them. Below we illustrate how ICH GCP principles can be implemented in different settings. We have recently conducted in Asia (Hechi, China; Karachi, Pakistan; Hue, Vietnam; North Jakarta, Indonesia and Kolkata, India) large-scale cluster-randomized effectiveness evaluations of the Vi polysaccharide typhoid fever vaccine (Vi PS project) among approximately 200,000 individuals(1)[Acosta CJ, Galindo CM, Ali M, Abu-Elyazeed R, Ochiai RL Danovaro-Holliday MC et al. A multi-country cluster randomized controlled effectiveness evaluation to accelerate the introduction of Vi polysaccharide typhoid vaccine in developing countries in Asia: rationale and design. TMIH 2005;10(12):1219-1228]. There is no doubt on the importance of ICH GCP in its contribution to ethical and scientifically sound clinical research. However, when the ICH GCP is implemented in ldcs some considerations must be made in order to adequately tailor them. Vaccine trials in ldcs are a frequent setting for such challenges because of the increased global interest conducting health research in such countries. The ICH GCP principles are discussed below within the framework of this recent typhoid fever vaccine study experience.

Developing Countries↗

PubMed2006

Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: an experience from a cluster-randomized double-blinded vaccine trial [NCT00125047].

OBJECTIVE: To determine the safety and logistic feasibility of a mass immunization strategy outside the local immunization program in the pediatric population of urban squatter settlements in Karachi, Pakistan. METHODS: A cluster-randomized double blind preventive trial was launched in August 2003 in 60 geographic clusters covering 21,059 children ages 2 to 16 years. After consent was obtained from parents or guardians, eligible children were immunized parenterally at vaccination posts in each cluster with Vi polysaccharide or hepatitis A vaccine. Safety, logistics, and standards were monitored and documented. RESULTS: The vaccine coverage of the population was 74% and was higher in those under age 10 years. No life-threatening serious adverse events were reported. Adverse events occurred in less than 1% of all vaccine recipients and the main reactions reported were fever and local pain. The proportion of adverse events in Vi polysaccharide and hepatitis A recipients will not be known until the end of the trial when the code is broken. Throughout the vaccination campaign safe injection practices were maintained and the cold chain was not interrupted. Mass vaccination in slums had good acceptance. Because populations in such areas are highly mobile, settlement conditions could affect coverage. Systemic reactions were uncommon and local reactions were mild and transient. Close community involvement was pivotal for information dissemination and immunization coverage. CONCLUSION: This vaccine strategy described together with other information that will soon be available in the area (cost/effectiveness, vaccine delivery costs, etc) will make typhoid fever control become a reality in the near future.

Journal Article↗

PubMed2006

Enhanced disease surveillance through private health care sector cooperation in Karachi, Pakistan: experience from a vaccine trial.

INTRODUCTION: In research projects such as vaccine trials, accurate and complete surveillance of all outcomes of interest is critical. In less developed countries where the private sector is the major health-care provider, the private sector must be included in surveillance systems in order to capture all disease of interest. This, however, poses enormous challenges in practice. The process and outcome of recruiting private practice clinics for surveillance in a vaccine trial are described. METHODS: The project started in January 2002 in two urban squatter settlements of Karachi, Pakistan. At the suggestion of private practitioners, a phlebotomy team was formed to provide support for disease surveillance. Children who had a reported history of fever for more than three days were enrolled for a diagnosis. RESULTS: Between May 2003 and April 2004, 5540 children younger than 16 years with fever for three days or more were enrolled in the study. Of the children, 1312 (24%) were seen first by private practitioners; the remainder presented directly to study centres. In total, 5329 blood samples were obtained for microbiology. The annual incidence of Salmonella typhi diagnosed by blood culture was 407 (95% confidence interval (95% CI), 368-448) per 100 000/year and for Salmonella paratyphi A was 198 (95% CI, 171-227) per 100 000/year. Without the contribution of private practitioners, the rates would have been 240 per 100 000/year (95% CI, 211-271) for S. typhi and 114 (95% CI, 94-136) per 100 000/year for S. paratyphi A. CONCLUSION: The private sector plays a major health-care role in Pakistan. Our experience from a surveillance and burden estimation study in Pakistan indicates that this objective is possible to achieve but requires considerable effort and confidence building. Nonetheless, it is essential to include private health care providers when attempting to accurately estimate the burden of disease in such settings.

Adolescent↗

PubMed2005

A multi-country cluster randomized controlled effectiveness evaluation to accelerate the introduction of Vi polysaccharide typhoid vaccine in developing countries in Asia: rationale and design.

Phase-III vaccine efficacy trials typically employ individually randomized designs intended to ensure that measurements of vaccine protective efficacy reflect only direct vaccine effects. As a result, decisions about introducing newly licensed vaccines into public health programmes often fail to consider the substantially greater protection that may occur when a vaccine is deployed in public health programmes, due to the combination of direct plus indirect vaccine protective effects. Vaccine total protection can be better evaluated with cluster randomized trials. Such a design was considered to generate policy relevant data to accelerate the rationale introduction of the licensed typhoid fever Vi polysaccharide (PS) vaccine in Asia by the Diseases of the Most Impoverished (DOMI) typhoid fever programme. The DOMI's programme multi-country study is one of the largest cluster randomized vaccine trials ever mounted in Asia, which includes approximately 200,000 individuals. Its main objective is to determine the effectiveness of a licensed Vi PS vaccine. The rationale and design of this study are discussed. Preliminary results are presented that determined the final planning of the trial before immunization. Important methodological and practical issues regarding vaccine cluster randomized designs are illustrated.

Adolescent↗

PubMed2005

Pandemic serovars (O3:K6 and O4:K68) of Vibrio parahaemolyticus associated with diarrhea in Mozambique: spread of the pandemic into the African continent.

Forty-two episodes of Vibrio parahaemolyticus infections were detected in Beira, Mozambique, from January to May 2004. The majority of the isolates (81%) belonged to the pandemic serovars (O3:K6 and O4:K68) of V. parahaemolyticus. The pandemic serovars were positive by group-specific PCR (GS-PCR) and a PCR specific for open reading frame ORF8 (ORF8-PCR), which are molecular markers of the pandemic clone, and were positive for tdh but negative for trh. The remaining 19% of the strains also possessed the tdh gene but were GS-PCR and ORF8-PCR negative and did not belong to the pandemic serovars. Patients with V. parahaemolyticus infection were older (mean age, 27 years) than patients infected by other diarrheal agents (mean age, 21 years). Ten percent of diarrhea patients from whom no V. parahaemolyticus was cultured were severely dehydrated, but none of the V. parahaemolyticus cases were severely dehydrated. This is the first report of the isolation of pandemic strains of V. parahaemolyticus in sub-Saharan Africa and clearly indicates that the pandemic of V. parahaemolyticus has spread into the African continent.

Adult↗