BackgroundMalaria presents a diagnostic challenge in most tropical countries. Microscopy remains the gold standard for diagnosing malaria infections in clinical practice and research. However, microscopy is labour intensive, requires significant skills and time, which causes therapeutic delays. The objective of obtaining result quickly from the examination of blood samples from patients with suspected malaria is now made possible with the introduction of rapid malaria diagnostic tests (RDTs). Several RDTs are available, which are fast, reliable and simple to use and can detect Plasmodium falciparum and non-falciparum infections or both. A study was conducted in tribal areas of central India to measure the overall performance of several RDTs for diagnosis of P. falciparum and non-falciparum infections in comparison with traditional and molecular techniques. Such data will be used to guide procurement decisions of policy makers and programme managers.MethodsFive commercially available RDTs were tested simultaneously in field in parallel with peripheral blood smears in outbreak-affected areas. The evaluation is designed to provide comparative data on the performance of each RDT. In addition, molecular method i.e. polymerase chain reaction (PCR) was also carried out to compare all three methods.ResultsA total of 372 patients with a clinical suspicion of malaria from Bajag Primary Health Centre (PHC) of district Dindori and Satanwada PHC of district Shivpuri attending the field clinics of Regional Medical Research Centre were included in the study. The analysis revealed that the First Response Malaria Antigen pLDH/HRP2 combo test was 94.7% sensitive (95% CI 89.5-97.7) and 69.9% specific (95% CI 63.6-75.6) for P. falciparum. However, for non-falciparum infections (Plasmodium vivax) the test was 84.2% sensitive (95% CI 72.1-92.5) and 96.5% specific (95% CI 93.8-98.2). The Parascreen represented a good alternative. All other RDTs were relatively less sensitive for both P. falciparum and non-falciparum infections.ConclusionsThe results in this study show comparative performance between microscopy, various RDTs and PCR. Despite some inherent limitation in the five RDTs tested, First Response clearly has an advantage over other RDTs. The results suggest that RDTs could play and will play an important role in malaria diagnosis.

The objective of this study was to demonstrate the utility of dengue virus (DENV) non structural protein 1 (NS1) based rapid diagnostic test (RDT) for use in tribal and difficult to reach areas for early dengue (DEN) diagnosis in acute phase patients and evaluate its sensitivity and specificity against DENV NS1 enzyme linked immune sorbent assay (ELISA) and real time reverse transcriptase polymerase chain reaction (qRT-PCR). The DENV NS1 RDT was used for preliminary diagnosis during outbreaks in difficult to reach rural and tribal areas. The diagnosis was confirmed by DENV NS1 ELISA in the laboratory. The samples were also tested and serotyped by qRT-PCR. The results were evaluated using statistical tests. The DENV NS1 RDT showed 99.2% sensitivity and 96.0% specificity when analyzed using DENV NS1 ELISA as standard. The specificity and sensitivity of the RDT when compared with qRT-PCR was 93.6% and 91.1%, respectively. The serotype specific evaluation showed more than 90% sensitivity and specificity for DENV-1, 2, and 3. The RDT proved a good diagnostic tool in difficult to reach rural and tribal areas. Further evaluation studies with different commercially available RDTs in different field conditions are essential, that will help clinicians and patients for treatment and programme managers for timely intervention.

Dengue is regarded as the most important arboviral disease. Although sporadic cases have been reported, serotypes responsible for outbreaks have not been identified from central India over the last 20 years. We investigated two outbreaks of febrile illness, in August and November 2012, from Korea district (Chhattisgarh) and Narsinghpur district (Madhya Pradesh), respectively. Fever and entomological surveys were conducted in the affected regions. Molecular and serological tests were conducted on collected serum samples. Dengue-specific amplicons were sequenced and phylogenetic analyses were performed. In Korea and Narsinghpur districts 37·3% and 59% of cases were positive, respectively, for dengue infection, with adults being the worst affected. RT-PCR confirmed dengue virus serotype 1 genotype III as the aetiology. Ninety-six percent of infections were primary. This is the first time that dengue virus 1 outbreaks have been documented from central India. Introduction of the virus into the population and a conducive mosquitogenic environment favouring increased vector density caused the outbreak. Timely diagnosis and strengthening vector control measures are essential to avoid future outbreaks.

Influenza A(H1N1)pdm09 virus pandemic struck India in 2009 and continues to cause outbreaks in its post-pandemic phase. Diminutive information is available about influenza A(H1N1)pdm09 from central India. This observational study presents epidemiological and molecular findings for the period of 6 years. Throat swab samples referred from districts of Madhya Pradesh were subjected to diagnosis of influenza A(H1N1)pdm09 following WHO guidelines. Clinical and epidemiological data were recorded and analyzed. Hemagglutinin (HA) gene sequencing and phylogenetic analysis were performed. The H275Y mutation responsible for antiviral resistance was tested using allelic real-time RT-PCR. Out of 7365 tested samples, 2406 (32.7%) were positive for influenza A(H1N1)pdm09, of which 363 (15.08%) succumbed to infection. Significant trends were observed in positivity (χ = 50.8; P < 0.001) and mortality (χ = 24.4; P < 0.001) with increasing age. Mutations having clinical and epidemiological importance were detected. Phylogenetic analysis of HA gene sequences revealed that clade 7, 6A, and 6B viruses were in circulation. Oseltamivir resistance was detected in three fatal cases. Influenza A(H1N1)pdm09 viruses having genetic diversity were detected from central India and continues to be a concern for public health. This study highlights the need of year-round monitoring by establishment of strong molecular and clinical surveillance program.

No abstract