Rubella Seroprevalence and real-time PCR detection of RUBV among Congolese pregnant women

Abstract Background Rubella is an acute infectious disease caused by Rubella virus (RUBV). RUBV remains an important pathogen worldwide, causing approximately 100 000 cases of congenital rubella syndrome (CRS) every year; and the most severe consequence of rubella is teratogenicity. The aim of this study was to estimate the prevalence of RUBV IgG antibodies and determine RUBV genotypes in Congolese pregnant women in Kongo central province, Democratic Republic of Congo (DRC). Methods This was a prospective cross-sectional study that consisted of a laboratory analysis of blood samples from 78 pregnant women to check for the presence of RUBV IgG antibodies, and also determine RUBV genotypes in seropositive samples (using primers targeting RUBV nucleoprotein), with the use of serological and molecular methods, respectively. Participants were pregnant women attending antenatal care clinics (ANC) at two health zones of Kisantu town in DRC. They were followed-up from the first to third trimester. Those who were negative for RUBV antibodies at the initial assay (first trimester) were tested in the second and, eventually, the third trimester. Results An overall rubella seroprevalence of 58.97% was observed, whereas RUBV nucleoprotein was detected in 60% of randomly selected 30 blood samples among the 46 RUBV seropositive pregnant women. Five (27.77%) of positive samples were positive for both RUBV genotypes (RV8633/9112 and RV8945/9577), whereas 11 (61.11%) of them were positive for RV8633/9112 and two (11.11%) were positive for RV8945/9577 only. Regarding rubella clinical signs and complications, two subjects (2.56%) presented with fever, whereas five pregnant women (6.41%) had experienced abortion. None (0%) of the participants has been vaccinated against RUBV. Conclusions Findings from this study suggest that RUBV is prevalent in Congolese pregnant women. Further research is required to elucidate the molecular epidemiology of RUBV in order to design a rational rubella surveillance and control program in DRC

Species composition and distribution of the Anopheles gambiae complex circulating in Kinshasa

Understanding the distribution of Anopheles species is essential for planning and implementing malaria control programmes. This study assessed the composition and distribution of cryptic species of the main malaria vector, the Anopheles gambiae complex, in different districts of Kinshasa. Anopheles were sampled using CDC light traps in the four Kinshasa districts between July 2021 and June 2022, and then morphologically identified. Equal proportions of Anopheles gambiae s.l. per site were subjected to polymerase chain reaction to identify the cryptic species of the Anopheles gambiae complex. Anopheles gambiae complex specimens were identified throughout Kinshasa. The average density significantly differed inside and outside households. Two species of this complex circulate in Kinshasa: Anopheles gambiae and Anopheles coluzzii. In all the study sites, Anopheles gambiae was the most widespread species. Our results provide an important basis for future studies on the ecology and dynamics of cryptic species of the Anopheles gambiae complex in Kinshasa

Effect of the Mass Distribution of ITNs in an Endemic Area with a High Entomological Index, the Case of Bandundu-City, Kwilu, DRC

The bio-efficacy of Yorkol-branded ITNs collected from Bandundu-city was assessed on the Kisumu strain and wild specimens of Anopheles gambiae. The susceptibility of the wild An. gambiae s.l. was tested to select insecticides. Adult An. gambiae s.l. sampled by PSC and HLC were screened for the presence of Plasmodium falciparum. Blood samples were diagnosed by microscopy and RDTs. ITN distributed in Bandundu-city were fully effective on the Kisumu strain, but on wild An. gambiae s.l. population (22.3 ± 11.5%). Anopheles gambiae s.l. was the main vector in Bandundu. No significant difference was observed between the entomological indices before and after the deployment of nets (OR = 0.8; p = 0.39). Wild An. gambiae s.l. populations were resistant to pyrethroids and DDT, with the restoration of the susceptibility to pyrethroids post pre-exposure to PBO. Plasmodium falciparum was the main parasite species and was found alone or mixed with. P. malariae or P. ovale. The confirmation rates by microscopy and RDT were respectively 57.9% and 53.6%. Nets deployed in Bandundu-city were not effective on wild An. gambiae s.l. populations. This operational failure is likely explained by the observed resistance to pyrethroids. In the future only PBO-net should be deployed Bandundu-city

HumBug – An Acoustic Mosquito Monitoring Tool for use on budget smartphones

Abstract Mosquito surveys are time‐consuming, expensive and can provide a biased spatial sample of occurrence data—the data often representing the location of the surveys, not the occurrence of the mosquitoes. We present the HumBug project, an acoustic system that can turn any Android smartphone into a mosquito sensor. Our sensor has the potential to significantly increase the quantity of mosquito occurrence data as well as access locations that are more difficult to survey by traditional means. We describe our database of wild‐captured mosquito fight tone audio data and outline our mosquito detection algorithms that these data train. We also present our MozzWear App, designed to work on budget smartphones, which, together with our HumBug Net (an adapted traditional bednet), facilitates data collection and allows the user to record and directly upload mosquito flight tones from any dwelling with a bednet in the field. Our HumBug system has the potential to vastly increase our understanding of the distribution of mosquito species in space and time and greatly improve surveys needed to assess the success or failure of ongoing vector control measures. At a time when the WHO reports a plateauing in the decade‐long decline in malaria mortality rates, this new technological solution for surveying mosquito vectors will provide a timely new resource