Challenges in Conducting Multicentric Infectious Giardia Diarrhea Clinical Studies in India


Multicentric studies on diarrhea are essential for comprehending its epidemiology, causes, and treatment outcomes.

Image credit: Jafree |

Image credit: Jafree |

Diarrheal diseases place a significant burden on public health in India, particularly among children and vulnerable populations. Unfortunately, diarrhea often goes untreated in our country.

Diarrhea kills 2,195 children every day—more than AIDS, malaria, and measles combined. Diarrheal diseases account for one in nine child deaths worldwide, making diarrhea the second leading cause of death among children under 5 years of age.

Many times, we disregard our body's signals and resort to antibiotics as a quick fix. However, if we pay closer attention to these symptoms and take proactive measures, we can reduce our reliance on antibiotics, especially for simple cases of diarrhea.

To gain a deeper understanding of this situation, we conducted a multicentric study on the antiprotozoal agent nitazoxanide. Multicentric studies on diarrhea are essential for comprehending its epidemiology, causes, and treatment outcomes.

Yet, conducting such studies in a vast and diverse country such as India presents numerous challenges. This article aims to delve into the obstacles faced during a multicentric diarrhea study in India and the strategies employed to overcome them. Additionally, we will explore nitazoxanide, a commonly used drug for diarrhea treatment.

The below listed challenges were raised while conducting the study:

  • Getting Giardia positive cases, which led to high screen failure rate
  • Analysis of stool sample at multiple sites
  • Stool sample logistic management in case of central lab
  • Seasonal variation for the conduct of the study
  • Reluctance of patients to participate in the study
  • High screen failure rate

Challenge 1: Analysis of Stool Samples at Multiple Centers to Get Giardia-Positive Case

To enroll approximately 400 patients, 1,000 patients were assessed. Throughout the entire study, a total of 1,052 samples were analyzed to achieve the desired number of patients.

Analyzing a large number of stool samples from different centers can be a daunting task, often time-consuming and posing logistical complexities. To address this challenge and streamline the analysis process, local laboratories in each center were utilized. These local labs were well-equipped and trained to follow a synchronized process, ensuring consistency in the analysis of stool samples and facilitating a common outcome.

A novel methodology involving centrifugation of stool samples

To rule out a false negative, we implemented the approach of centrifugation of sample—as well as the evaluation of at least two to three samples—which was uniformly employed across all laboratory settings to ascertain the presence of Giardia lamblia, even in instances characterized by disparate distribution of the infectious pathogen within the sample. This innovative approach was adopted to address the challenge posed by the irregular spatial dispersion of the pathogen, which could potentially result in erroneous negative outcomes using conventional testing methodologies. By subjecting the stool specimens to centrifugal forces, the constituent elements of the sample were fractionated into distinct layers, facilitating a meticulous examination.

In this procedure, the froth, intermediary layer, and sedimentary stratum of the centrifuged samples were meticulously scrutinized. This comprehensive analysis enabled the precise identification of Giardia lamblia, thereby ensuring its accurate detection irrespective of its non-uniform distribution within the sample. This strategy significantly mitigated the prospect of false-negative findings and heightened the precision of the study's outcomes.

By introducing this innovative centrifugation technique, the research team not only demonstrated their resolve to surmount challenges but also showcased the potential of innovative thinking in resolving intricate predicaments in research and diagnostics. The screen failure rate was decreased by 15% to 20% by implementing this technique. The study was conducted within the stipulated time, with efficient data analysis leveraging local resources.

Challenge 2: Transfer of Stool Samples to the Central Lab

Transporting stool samples from multiple sites across the country to a central laboratory is crucial to maintain sample integrity and avoid potential bias. This challenge was overcome through the strategic implementation of a local lab network, which acted as collection points where the samples were initially analyzed.

Following a standardized procedure, separate samples were then transferred to the lab, which acted as central lab for three to four sites. This approach minimized the risk of sample degradation during transportation and ensured efficient sample management.

Challenge 3: Conducting the Study During the Summer Season

Conducting the study during the summer season, which typically exhibits a lower incidence of diarrheal diseases compared to other seasons, posed a challenge. This lower disease burden resulted in fewer patients being enrolled in the study, affecting the recruitment rate. To address this challenge, the study team conducted prescreening activities, including health checkup camps, to increase awareness about the study and to actively recruit eligible patients.

Moreover, the scope of the study was expanded by adding more sites, specifically targeting areas with higher disease prevalence during the rainy season. This approach aimed to boost patient recruitment during a period of peak diarrhea cases.

The study's temporal scope was extended to encompass the rainy season, a period during which the targeted patient population, primarily prevalent in slum localities, exhibited a pronounced upsurge. These colonies emerged as promising reservoirs for assembling the requisite patient cohort, thereby facilitating a robust and representative patient pool for the study's objectives.

Challenge 4: Reluctance of Patients to Participate in the Study

One significant challenge faced during the study was the reluctance of patients to participate, considering the stool sample analysis report took a minimum of three days. Due to the immediate need for treatment, many patients preferred seeking immediate medical attention rather than waiting for study enrollment and treatment administration.

To overcome this challenge, the study team ensured that enrolled patients received prompt treatment. They prioritized the administration of treatment immediately and minimized the waiting time required for pathological analysis.

Additionally, patients were informed of their willingness to participate and withdraw from the study at any time, respecting their autonomy and preferences. To mitigate the risk of dehydration among the screened patients, a standardized protocol was implemented, entailing the administration of oral rehydration solution (ORS) to all individuals undergoing screening.

This approach served a dual purpose. First, it safeguarded individuals from progressing into a dehydrated state, and second, it fostered enhanced patient engagement in the study. By offering immediate intervention in the form of ORS subsequent to the screening process, participants were not only shielded from dehydration, but were also incentivized to participate in the study due to the immediate and beneficial care received.

Challenge 5: Screening Failures Due to Giardia in the Duodenum

The presence of Giardia in the duodenum posed a challenge, leading to higher rates of false-negative results and increased screen failures. To address this issue, the study team developed an innovative approach. They implemented a unique process of centrifuging the stool samples and analyzing them layer by layer. By carefully examining the froth, middle layer, and sedimental layer of the samples, researchers minimized the chances of false-negative reports and improved the accuracy of the study results.

Challenge 6: High Screen Failure Rate

Even after selecting sites based on disease prevalence and location, the study faced a challenge of a high screen failure rate. The expected number of eligible participants was not met, leading to sites that were not recruiting.

To overcome this challenge, new sites were initiated, particularly targeting areas with a significant slum population and higher disease prevalence. By expanding the research scope to include these areas, the study aimed to improve the representation of the target population and increase the likelihood of successfully enrolling eligible participants.

Nitazoxanide: A Treatment Option for Diarrhea

In the context of diarrhea treatment, it is crucial to mention nitazoxanide, a commonly used drug. Nitazoxanide is a broad-spectrum antiparasitic and antiviral medication that has demonstrated efficacy in treating diarrhea caused by various pathogens, including parasites and viruses.

It acts by inhibiting the replication of the causative organisms, thereby reducing the duration and severity of diarrhea. Nitazoxanide is generally well-tolerated and has been recommended by healthcare authorities for the treatment of diarrhea in certain cases.

In the context of India, the prevailing practice of empirically administering antibiotics in such instances contributes significantly to the development of antibiotic resistance at the individual level. Conversely, the employment of antiprotozoal agents such as nitazoxanide serves as an instrumental strategy in mitigating the progression of resistance.

In the study, the numbers and proportion of patients with success at the end were higher in the nitazoxanide treatment cohort than placebo by approximately 44%. The proportion of treatment success is statistically superior to placebo.


In conclusion, our journey in investigating the effectiveness of nitazoxanide for managing acute infectious diarrhea was marked by a series of challenges. We encountered obstacles in sample analysis, logistics, patient recruitment, and screen failures—each demanding creative solutions.

We successfully tackled these hurdles by employing a range of strategies. We leveraged local laboratory resources, initiated prescreening initiatives, established meticulous sample handling and transit protocols, ensured prompt treatment delivery, conducted motivating on-site visits, optimized our laboratory supplies, and expanded our research sites.

Notably, the inclusion of nitazoxanide in our treatment options emerged as a valuable asset in enhancing diarrhea management infection by Giardia lamblia. Post differential diagnosis of Giardia lamblia by stool examinations.

By effectively addressing these challenges and deepening our understanding of the disease landscape in India, we have laid a strong foundation for developing strategic therapeutic interventions. These interventions aim to alleviate the public health burden posed by this ailment and reduce its prevalence, ultimately improving the lives of those affected by infectious diarrhea in our country.

Acknowledgement and Appreciation

We would like to extend our heartfelt gratitude and appreciation to all those who have contributed to the completion of this article. First and foremost, we express our sincere thanks to the sites and patients who participated in the clinical trial discussed in this article. Their dedication and cooperation were instrumental in the success of the research endeavor. Without their involvement, the study would not have been possible.

We would also like to acknowledge Raptim Management for their invaluable support, guidance, and expertise throughout the duration of the clinical trial. Their commitment to excellence and partnership played a crucial role in overcoming challenges and achieving milestones.

Lastly, we extend our appreciation to our readers for their interest in our work. It is our hope that this article contributes to the advancement of knowledge in the field and inspires further research and collaboration.


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