Wednesday, October 20, 2010

AIDS Vaccine for Asia Network (AVAN): Expanding the Regional Role in Developing HIV Vaccines

Kent SJ, Cooper DA, Chhi Vun M, Shao Y, Zhang L, et al. (2010) AIDS Vaccine for Asia Network (AVAN): Expanding the Regional Role in Developing HIV Vaccines. PLoS Med 7(9): e1000331. doi:10.1371/journal.pmed.1000331

The HIV/AIDS pandemic continues to spread and an AIDS vaccine is urgently needed. While facing unprecedented challenges, AIDS vaccine development activities are continuing around the globe. Recent results of the Thai Phase III vaccine trial are renewing such efforts. In accordance with the goals of the Global HIV Vaccine Enterprise, there is now clear recognition of the role that regional alliances can play in fostering and facilitating AIDS vaccine development, and there is broad agreement that international collaborations are the most effective way forward to develop and evaluate the next generation of AIDS vaccine candidates.

In response to these challenges, the Asian region has recently formed the AIDS Vaccine for Asia Network (AVAN).

AVAN has been initiated to meet these needs and actively facilitate the development of a regional AIDS vaccine strategy that accelerates research and development of an AIDS vaccine through government advocacy, improved coordination and harmonization of research; develops clinical trial and manufacturing capacity; supports ethical and regulatory frameworks; and ensures community participation.

Wednesday, October 6, 2010

Scripps researchers develop new detection test for river blindness parasite

Innovation will help eliminate tropical malady

In a press release by the Scripps Research Institute in La Jolla, california, the institute announced that its scientists have developed the first screening method that rapidly identifies individuals with active river blindness, a parasitic disease that afflicts an estimated 37 million people. The test could change the current strategy of mass treatment in areas where river blindness, also known as onchocerciasis, is suspected.

The study was published online on October 5, 2010, by the journal PLOS Neglected Tropical Diseases.

"A sensitive and reproducible diagnostic test for this disease is crucial for the success of worldwide control and elimination programs," said Kim Janda, Ph.D., a professor in the Departments of Chemistry and Immunology and Microbial Science, member of The Skaggs Institute for Chemical Biology, and director of The Worm Institute for Research and Medicine (WIRM) at Scripps Research. "This diagnostic tool could be a game-changer for how the disease will be treated in the future."

Judith Denery, Ph.D., a senior research associate in the Janda laboratory and the paper's first author, adds, "Because current tests often give false negatives, they are unreliable indicators of infection. For organizations such as the World Health Organization and others working to eliminate the disease, this lack of accuracy is frustrating, time-consuming, and costly."

Enhanced Detection, Diagnosis of Leishmaniasis in Bangladesh

Mondal D, Nasrin KN, Huda MM, Kabir M, Hossain MS, et al. (2010) Enhanced Case Detection and Improved Diagnosis of PKDL in a Kala-azar-Endemic Area of Bangladesh. PLoS Negl Trop Dis 4(10): e832. doi:10.1371/journal.pntd.0000832

To support the Bangladesh National Kala-azar Elimination Programme (NKEP), the group investigated the feasibility of using trained village volunteers for detecting post-kala-azar dermal leishmaniasis (PKDL) cases, using polymerase chain reaction (PCR) for confirmation of diagnosis and treatment compliance by PKDL patients in Kanthal union of Trishal sub-district, Mymensingh, Bangladesh.

In this cross-sectional study, Field Research Assistants (FRAs) conducted census in the study area, and the research team trained village volunteers on how to look for PKDL suspects. The trained village volunteers (TVVs) visited each household in the study area for PKDL suspects and referred the suspected PKDL cases to the study clinic. The suspected cases underwent physical examinations by a qualified doctor and rK39 strip testing by the FRAs and, if positive, slit skin examination (SSE), culture, and PCR of skin specimens and peripheral buffy coat were done. Those with evidence of Leishmania donovani (LD) were referred for treatment. All the cases were followed for one year.

The total population of the study area was 29,226 from 6,566 households. The TVVs referred 52 PKDL suspects. Probable PKDL was diagnosed in 18 of the 52 PKDL suspect cases, and PKDL was confirmed in 9 of the 18 probable PKDL cases. The prevalence of probable PKDL was 6.2 per 10,000 people in the study area. Thirteen PKDL suspects self-reported from outside the study area, and probable and confirmed PKDL was diagnosed in 10 of the 13 suspects and in 5 of 10 probable PKDL cases respectively. All probable PKDL cases had hypopigmented macules. The median time for PKDL development was 36 months (IQR, 24–48). Evidence of the LD parasite was documented by SSE and PCR in 3.6% and 64.3% of the cases, respectively. PCR positivity was associated with gender and severity of disease. Those who were untreated had an increased risk (odds ratio = 3.33, 95%CI 1.29–8.59) of having persistent skin lesions compared to those who were treated. Patients' treatment-seeking behavior and treatment compliance were poor.

Improved detection of PKDL cases by TVVs is feasible and useful. The NKEP should promote PCR for the diagnosis of PKDL and should find ways for improving treatment compliance by patients.

External Quality Control Assessment for the Molecular Diagnosis of Dengue Infections

Domingo C, Niedrig M, Teichmann A, Kaiser M, Rumer L, et al. (2010) 2nd International External Quality Control Assessment for the Molecular Diagnosis of Dengue Infections. PLoS Negl Trop Dis 4(10): e833. doi:10.1371/journal.pntd.0000833

Currently dengue viruses (DENV) pose an increasing threat to over 2.5 billion people in over 100 tropical and sub-tropical countries worldwide. International air travel is facilitating rapid global movement of DENV, increasing the risk of severe dengue epidemics by introducing different serotypes. Accurate diagnosis is critical for early initiation of preventive measures. Different reverse transcriptase PCR (RT-PCR) methods are available, which should be evaluated and standardized. Epidemiological and laboratory-based surveillance is required to monitor and guide dengue prevention and control programmes, i.e., by mosquito control or possible vaccination (as soon as an effective and safe vaccine becomes available).

The purpose of the external quality assurance (EQA) study described is to assess the efficiency and accuracy of dengue molecular diagnosis methods applied by expert laboratories.

Study Design
A panel of 12 human plasma samples was distributed and tested for DENV-specific RNA. The panel comprised 9 samples spiked with different DENV serotypes (DENV-1 to DENV-4), including 10-fold dilution series of DENV-1 and DENV-3. Two specificity controls consisted of a sample with a pool of 4 other flaviviruses and a sample with chikungunya virus. A negative control sample was also included.

Thirty-seven laboratories (from Europe, Middle East Asia, Asia, the Americas/Caribbean, and Africa) participated in this EQA study, and reports including 46 sets of results were returned. Performance among laboratories varied according to methodologies used. Only 5 (10.9%) data sets met all criteria with optimal performance, and 4 (8.7%) with acceptable performance, while 37 (80.4%) reported results showed the need for improvement regarding accomplishment of dengue molecular diagnosis. Failures were mainly due to lack of sensitivity and the presence of false positives.

The EQA provides information on each laboratory's efficacy of RT-PCR techniques for dengue diagnosis and indicates for most laboratories an urgent need to improve sensitivity and specificity.