Validation of RealAmp Method for the Diagnosis of Malaria in Endemic Areas of Brazil

• ClinicalTrials.gov Identifier: NCT02371395
• Recruitment Status: Completed
• First Posted: February 25, 2015
• Results First Posted: October 23, 2018
• Last Update Posted: October 23, 2018
• Sponsor: Centers for Disease Control and Prevention
• Collaborator: Evandro Chagas Institute of Clinical Research
• Information provided by (Responsible Party): Centers for Disease Control and Prevention

Study Description

Brief Summary:

Worldwide, approximately 2 billion people live in areas at risk for malaria with morbidity surpassing 250 million cases, with approximately 800,000 deaths, per year. Of the four species of malaria parasites that cause human infection, P. falciparum is responsible for the majority of severe malaria cases followed by P. vivax. Early and accurate diagnosis is essential for prompt and correct treatment, which can reduce the death rate and interrupt transmission. Currently, conventional methods for the diagnosis of malaria include microscopic examination of thin and thick blood smears and rapid diagnostic tests (RDTs). Light microscopy in practice typically detects parasitemia as low as 100 parasites/µl and it can differentiate species. The advantage of microscopy includes the ability to estimate parasitemia, the possibility to identify parasite stages, including gametocytes, and its low cost. However, this method is labor intensive, difficult to standardize, and requires well-trained microscopists. The majority of RDTs are based on detection of P. falciparum histidine-rich protein 2 (HRP-2) antigen and do not detect all malaria species. RDTs that detect lactose dehydrogenase (LDH) and aldolase generally broadly react with all four species of malaria parasites and therefore cannot differentiate among the species although efforts are underway to improve their performance for species detection. In settings where multiple malaria species co-circulate, molecular methods may be more reliable than microscopy and RDTs in accurately diagnosing the species of malaria parasites with low parasitemias. However, conventional molecular methods, such as nested polymerase chain reaction (nested PCR) or real-time PCR, are technically challenging and resource intensive and are generally restricted to reference laboratories due to the need for well-equipped laboratories. Recently, new molecular methods that can be used in field settings have been developed and this opens up new opportunities for exploring molecular tools for malaria diagnosis in endemic countries. With the objective of facilitating use of molecular tools for malaria control programs, the malaria laboratory at the Centers for Disease Control and Prevention (CDC) in Atlanta, USA developed a simple isothermal molecular method called Real-Time Fluorescence Loop-Mediated Isothermal Amplification (RealAmp) for the diagnosis of malaria. Currently, RealAmp primers exist for detecting the Plasmodium genus and the detection of P. falciparum and P. vivax species. The RealAmp method has great potential as a molecular tool for the diagnosis of malaria in the field (and other infections of major public health impact, such as HIV and tuberculosis). It can provide an alternative to conventional PCR-based diagnostic methods for field use in clinical and operational programs. The objective of this proposal is to validate the sensitivity of RealAmp for detection of malaria parasites in blood spots from patients with clinical diagnosis of malaria in two endemic states of Brazil with co-circulation of P. falciparum and P. vivax. In this evaluation, RealAmp and microscopic examination will be compared to a real-time PCR method as a reference test.

Condition or disease	Intervention/treatment
Malaria Diagnosis	Other: Realtime amplification (RealAmp)

Study Design

• Study Type: Observational
• Actual Enrollment: 1000 participants
• Observational Model: Cohort
• Time Perspective: Cross-Sectional
• Official Title: Validation of RealAmp Method for the Diagnosis of Malaria in Endemic Areas of Brazil
• Actual Study Start Date: January 2015
• Actual Primary Completion Date: June 2015
• Actual Study Completion Date: June 2015

Groups and Cohorts

Intervention Details:

• Other: Realtime amplification (RealAmp)
  Molecular assay for the diagnosis of malaria.

Outcome Measures

Primary Outcome Measures :

1. Malaria Diagnosis Using RealAmp and Microscopy. [ Time Frame: 12 months ]
   These are the results of the different tests used in the evaluation.

Eligibility Criteria

• Ages Eligible for Study: 7 Years and older (Child, Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No
• Sampling Method: Non-Probability Sample

Study Population

Patients with fever who present for malaria diagnosis and regular health posts.

Criteria

Inclusion Criteria:

• Age 7 years
• Signed informed consent for patients 18 years and older
• Signed parental/guardian consent form and assent from the patient (for those less than 18 years)
• Documented fever (auxiliary temperature greater than 37.5C) or self-reported fever in previous 24 hours in the absence of another obvious cause of fever
• First visit for current illness at the diagnostic post

Exclusion Criteria:

• Absence of fever or no history of fever
• Follow-up visit for the current illness
• No consent/assent to participate
• Antimalarial treatment use in previous 30 days

Contacts and Locations

Locations

Brazil

Hospital do Jurua

Cruzeiro do Sul, Brazil

Sponsors and Collaborators

Centers for Disease Control and Prevention

Evandro Chagas Institute of Clinical Research

Investigators

• Principal Investigator: Alexandre Macedo de Oliveira, MD; Centers for Disease Control and Prevention

More Information

• Responsible Party: Centers for Disease Control and Prevention
• ClinicalTrials.gov Identifier: NCT02371395
• Other Study ID Numbers: 6619
• First Posted: February 25, 2015
• Results First Posted: October 23, 2018
• Last Update Posted: October 23, 2018
• Last Verified: May 2015

Additional relevant MeSH terms:

Malaria; Protozoan Infections; Parasitic Diseases; Infections; Vector Borne Diseases