Figure 4

<p><b>A)</b> Gel electrophoresis of the conventional PCR amplification products showing the undigested 384-bp OPV amplicon DNA ladder (lane 1); negative controls (lanes 2–3); human specimens from 13 patients of the Bena Tshiadi healthcare district (lanes 4–13 and 15–18), and from 1 patient of the Yangala healthcare district (lane 14). <b>B)</b><i>BsrGI</i> digestion profile of 384-bp MPXV amplicons: banding patterns with 210- and 174-bp fragments.</p

Blotting papers showing six 6 spots with dried liquid exudate from pustules collected in one patient.

<p>One spot (arrow) was removed and processed for DNA-based identification of causative agents of the rash illness.</p

DNA-based identification of causative agents of rash illness outbreaks (2008 and 2009) in West Kasai province.

<p>Legend: Patients originated from the following healthcare districts: Bena Tshiadi, 1–13; Yangala, 14–22; Ndesha, 23–25.</p

Map of West Kasai Province.

<p>Areas affected by rash illness outbreaks are highlighted as follows: ▴: Bena Tshiadi healthcare zone (13 patients in 7 different villages). All cases were confirmed as monkeypox cases. Hourglass Symbol: Yangala healthcare zone (8 patients clustered in Tshikongo village). All were confirmed as varicella cases.♦: Ndesha healthcare zone in the outskirts of Kananga (3 patients clustered in Lubuyi village, several kilometers north of Kananga city). All were confirmed as varicella cases.</p

Multiple alignment of 14 kD DNA targets and design of primers and probes for the qPCR assay.

<p>Primers for qPCR and for the conventional PCR are shown in plain boxes whereas the pan-orthopoxvirus and specific variola virus probes are highlighted in a dashed boxes. The monkepoxvirus specific SNP (C→T) is arrowed. The pyrosequencing probe is indicated by a plain arrow.</p

Use of a rapid digital microfluidics-powered immunoassay for assessing measles and rubella infection and immunity in outbreak settings in the Democratic Republic of the Congo.

The Democratic Republic of the Congo (DRC) has a high measles incidence despite elimination efforts and has yet to introduce rubella vaccine. We evaluated the performance of a prototype rapid digital microfluidics powered (DMF) enzyme-linked immunoassay (ELISA) assessing measles and rubella infection, by testing for immunoglobulin M (IgM), and immunity from natural infection or vaccine, by testing immunoglobulin G (IgG), in outbreak settings. Field evaluations were conducted during September 2017, in Kinshasa province, DRC. Blood specimens were collected during an outbreak investigation of suspected measles cases and tested for measles and rubella IgM and IgG using the DMF-ELISA in the field. Simultaneously, a household serosurvey for measles and rubella IgG was conducted in a recently confirmed measles outbreak area. DMF-ELISA results were compared with reference ELISA results tested at DRC's National Public Health Laboratory and the US Centers for Disease Control and Prevention. Of 157 suspected measles cases, rubella IgM was detected in 54% while measles IgM was detected in 13%. Measles IgG-positive cases were higher among vaccinated persons (87%) than unvaccinated persons (72%). In the recent measles outbreak area, measles IgG seroprevalence was 93% overall, while rubella seroprevalence was lower for children (77%) than women (98%). Compared with reference ELISA, DMF-ELISA sensitivity and specificity were 82% and 78% for measles IgG; 88% and 89% for measles IgM; 85% and 85% for rubella IgG; and 81% and 83% for rubella IgM, respectively. Rubella infection was detected in more than half of persons meeting the suspected measles case definition during a presumed measles outbreak, suggesting substantial unrecognized rubella incidence, and highlighting the need for rubella vaccine introduction into the national schedule. The performance of the DMF-ELISA suggested that this technology can be used to develop rapid diagnostic tests for measles and rubella

Simple technique for in field samples collection in the cases of skin rash illness and subsequent PCR detection of orthopoxviruses and varicella zoster virus.

In case of outbreak of rash illness in remote areas, clinically discriminating monkeypox (MPX) from severe form of chickenpox and from smallpox remains a concern for first responders. OBJECTIVE: The goal of the study was therefore to use MPX and chickenpox outbreaks in Democratic Republic of Congo (DRC) as a test case for establishing a rapid and specific diagnosis in affected remote areas. METHODS: In 2008 and 2009, successive outbreaks of presumed MPX skin rash were reported in Bena Tshiadi, Yangala and Ndesha healthcare districts of the West Kasai province (DRC). Specimens consisting of liquid vesicle dried on filter papers or crusted scabs from healing patients were sampled by first responders. A field analytical facility was deployed nearby in order to carry out a real-time PCR (qPCR) assay using genus consensus primers, consensus orthopoxvirus (OPV) and smallpox-specific probes spanning over the 14 kD fusion protein encoding gene. A PCR-restriction fragment length polymorphism was used on-site as backup method to confirm the presence of monkeypox virus (MPXV) in samples. To complete the differential diagnosis of skin rash, chickenpox was tested in parallel using a commercial qPCR assay. In a post-deployment step, a MPXV-specific pyrosequencing was carried out on all biotinylated amplicons generated on-site in order to confirm the on-site results. RESULTS: Whereas MPXV proved to be the agent causing the rash illness outbreak in the Bena Tshiadi, VZV was the causative agent of the disease in Yangala and Ndesha districts. In addition, each on-site result was later confirmed by MPXV-specific pyrosequencing analysis without any discrepancy. CONCLUSION: This experience of rapid on-site dual use DNA-based differential diagnosis of rash illnesses demonstrates the potential of combining tests specifically identifying bioterrorism agents and agents causing natural outbreaks. This opens the way to rapid on-site DNA-based identification of a broad spectrum of causative agents in remote areas