Field evaluation of malaria rapid diagnostic tests for the diagnosis of P. falciparum and non-P. falciparum infections.

The objective of this study was to evaluate various malaria rapid diagnostic tests as a tool in the detection of P. falciparum and non-P. falciparum infections in field conditions. Four field surveys were conducted in malaria-endemic areas of Palawan and Davao del Norte, Philippines to validate the various rapid diagnostic tests, namely Diamed OptiMAL 48 (DiaMed AG, Switzerland), ParaHIT f (Span Diagnostics, India), Orchid OptiMAL, and Paracheck Pf (both from Orchid Biomedical Systems, India). The results of the various rapid diagnostic tests were compared to those of microscopy. Sensitivity, specificity and detection rates according to the level of parasitemia were used as parameters to describe the performance of the various rapid diagnostic tests in the field. Practical and operational assessments were also done. The results of the study show that the sensitivity and detection rates were generally lower than previously reported, with sensitivities ranging from 4.8% to 20.6%, except for Diamed OptiMAL 48, which had sensitivities of 78.8% to 96.8%, and detection rates of 50.0% to 96.8%. The rest had detection rates ranging from 0.0% to 50.0%. All the specificities ranged from 18.2% to 100.0%. Improper conditions at the time of manufacturing, storage, transport, and utilization may affect the validity of the results. Rapid diagnostic tests for malaria provide practical means of detecting malarial infections, especially in endemic areas. However, issues regarding variability in performance must to be addressed before they can be used as mainstream diagnostic tools.

Intestinal heterophyidiasis: an emerging food-borne parasitic zoonosis in southern Philippines.

Heterophyidiasis is an infection of the small bowel by minute intestinal flukes of the genus Heterophyes or related members of the family Heterophyidae. To provide a better understanding of this rarely reported condition, this study attempted to determine the infection rate, intensity of infection as well as the clinical spectrum of heterophyid infection. A stool survey was conducted in barangay San Isidro, Monkayo, Compostela Valley. Thirty-six percent of patients with history of bowel disturbance (abdominal discomfort/pain and/or diarrhea) in the past 4 weeks were found to have heterophyidiasis. All age groups were infected, with the youngest patient being 1 year 7 months of age, while the oldest patient was 73 years of age. Prevalence was highest in the 15 to 30 years old group at 55.3%. The most common clinical manifestations of heterophyidiasis were signs and symptoms of acid peptic or peptic ulcer disease. Early diagnosis and treatment are important to ensure prompt resolution of heterophyid infection, hence, decreased morbidity and decreased chances for complications like heart or brain involvement. Proficiency of laboratory staff should be enhanced to ensure accurate diagnosis which will then make appropriate treatment possible.