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The eradication of yaws caused by Treponema pallidum subsp. pertenue is constrained by the lack of rapid, accurate diagnosis. We sought to develop a molecular point-of-care test for the diagnosis of yaws. A loop-mediated isothermal amplification (LAMP) assay with primers targeting the conserved gene, tp0967, with visual detection by lateral flow test strip was developed and optimized. The limit of detection was evaluated while 63 samples from clinical cases of yaws and five samples with polymerase chain reaction (PCR)-confirmed syphilis were used to determine the sensitivity and specificity of the assay compared with the current molecular testing protocol. The developed LAMP assay was found to be optimal when run at 65°C for 30 minutes. The limit of detection from extracted DNA was 2.7 × 104 DNA copies/mL. The sensitivity of the LAMP assay using unextracted and DNA extracted samples were 0.67 and 1.00, respectively. None of the syphilis samples tested positive in any of the assays. We show the development of a fast and sensitive LAMP assay for yaws detected by lateral flow test strip. Using extracted DNA, the assay sensitivity is at par with real-time PCR-based detection. The assay can be adapted to minimal sample processing required for infield detection without DNA extraction.

The control of infectious diseases is seriously threatened by the increase in the number of microorganisms resistant to antimicrobial agents. Antibiotic-resistant bacteria have also been identified in the water environment. A field study was performed sampling drinking water sources in seven districts of southern Ghana targeting boreholes, dams, hand-dug wells, and streams during baseflow conditions. Bacteria were isolated ( N = 110 ) from a total of 67 water samples to investigate their antimicrobial susceptibility and to determine their carriage of select antibiotic resistance genes. Bacterial identification was performed using conventional selective media methods and the analytical profile index (API) method. Antibiotic susceptibility tests were carried out using the Kirby–Bauer method. Results indicated that all water sources tested were of poor quality based on the presence of fecal indicator organisms. The most commonly occurring bacterium isolated from water was Klebsiella spp. ( N = 24 , 21.8%), followed by E. coli ( N = 23 , 20.9%). Gram-negative bacteria isolates were most commonly resistant to cefuroxime (24.5%), while the Gram-positives were most commonly resistant to meropenem (21.3%). The highest rates of bacterial resistances to more than one antibiotic were observed in Klebsiella spp. (30.0%) followed by E. coli (27.8%). PCR was used to detect the presence of a select antibiotic resistance genes in the Gram-negative isolates. The presence of blaNDM-1, sull, tet(O), and tet(W) were observed in isolates from all water sources. In contrast, ermF was not detected in any of the Gram-negative isolates from any water source. Most (28.7%) of the resistance genes were observed in E. coli isolates. Reducing microbial contamination of the various water sources is needed to protect public health and to ensure the sustainability of this resource. This further calls for education of the citizenry.

Background: Loss of efcacy of diagnostic tests may lead to untreated or mistreated malaria cases, compromising case management and control. There is an increasing reliance on rapid diagnostic tests (RDTs) for malaria diagnosis, with the most widely used of these targeting the Plasmodium falciparum histidine-rich protein 2 (PfHRP2). There are numerous reports of the deletion of this gene in P. falciparum parasites in some populations, rendering them unde‑ tectable by PfHRP2 RDTs. The aim of this study was to identify P. falciparum parasites lacking the P. falciparum histidine rich protein 2 and 3 genes (pfhrp2/3) isolated from asymptomatic and symptomatic school-age children in Kinshasa, Democratic Republic of Congo. Methods: The performance of PfHRP2-based RDTs in comparison to microscopy and PCR was assessed using blood samples collected and spotted on Whatman 903™ flter papers between October and November 2019 from schoolage children aged 6–14 years. PCR was then used to identify parasite isolates lacking pfhrp2/3 genes. Results: Among asymptomatic malaria carriers (N=266), 49%, 65%, and 70% were microscopy, PfHRP2_RDT, and pfdh-qPCR positive, respectively. The sensitivity and specifcity of RDTs compared to PCR were 80% and 70% while the sensitivity and specifcity of RDTs compared to microscopy were 92% and 60%, respectively. Among sympto‑ matic malaria carriers (N=196), 62%, 67%, and 87% were microscopy, PfHRP2-based RDT, pfdh-qPCR and positive, respectively. The sensitivity and specifcity of RDTs compared to PCR were 75% and 88%, whereas the sensitivity and specifcity of RDTs compared to microscopy were 93% and 77%, respectively. Of 173 samples with sufcient DNA for PCR amplifcation of pfhrp2/3, deletions of pfhrp2 and pfhrp3 were identifed in 2% and 1%, respectively. Three (4%)of samples harboured deletions of the pfhrp2 gene in asymptomatic parasite carriers and one (1%) isolate lacked the pfhrp3 gene among symptomatic parasite carriers in the RDT positive subgroup. No parasites lacking the pfhrp2/3 genes were found in the RDT negative subgroup. Conclusion: Plasmodium falciparum histidine-rich protein 2/3 gene deletions are uncommon in the surveyed popu‑ lation, and do not result in diagnostic failure. The use of rigorous PCR methods to identify pfhrp2/3 gene deletions is encouraged in order to minimize the overestimation of their prevalence., Malaria Journal, 21(1), art. no. 126; 2022

Background Malaria remains a major public health concern in the Democratic Republic of Congo (DRC), and school-age children are relatively neglected in malaria prevalence surveys and may constitute a significant reservoir of transmission. This study aimed to understand the burden of malaria infections in school-age children in Kinshasa/DRC. Methods A total of 634 (427 asymptomatic and 207 symptomatic) blood samples collected from school-age children aged 6 to 14 years were analysed by microscopy, RDT and Nested-PCR. Results The overall prevalence of Plasmodium spp. by microscopy, RDT and PCR was 33%, 42% and 62% among asymptomatic children and 59%, 64% and 95% in symptomatic children, respectively. The prevalence of Plasmodium falciparum, Plasmodium malariae and Plasmodium ovale spp. by PCR was 58%, 20% and 11% among asymptomatic and 93%, 13% and 16% in symptomatic children, respectively. Among P. ovale spp., P. ovale curtisi, P. ovale wallikeri and mixed P. ovale curtisi + P. ovale wallikeri accounted for 75%, 24% and 1% of infections, respectively. All Plasmodium species infections were significantly more prevalent in the rural area compared to the urban area in asymptomatic infections (p Plasmodium with P. falciparum infections in the rural and the urban areas, respectively, whereas in symptomatic malaria infections, it was 22% and 26%, respectively. Few children carried single infections of P. malariae (2.2%) and P. ovale spp. (1.9%). Conclusion School-age children are at significant risk from both asymptomatic and symptomatic malaria infections. Continuous systematic screening and treatment of school-age children in high-transmission settings is needed.

Q fever is a zoonotic disease caused by Coxiella burnetii, a causative agent of abortion in livestock and febrile illness in humans. Outbreaks of human cases of Q fever have been reported in Australia and the Netherlands, which was linked to abortions in goat and sheep farms. In Ghana, information on Q fever in both livestock and humans is scanty. This study sought to determine the seroprevalence of Q fever in livestock in the Tongu area of the Volta region of Ghana. It was a cross sectional study with blood sampled from 204 cattle, 158 sheep and 100 goats. An indirect ELISA test was performed to detect Q fever antibodies in the serum of livestock. A total of 20 farms were sampled across the municipalities and an overall prevalence of Q fever was 21.6%. Specie‐specific prevalence was 28.4% (45/158) for sheep, 21.7% (45/204) for cattle and 10% (10/100) for goats. Abortions were reported on all the farms sampled and most farmers lived in close proximity to the farms sampled. Q fever is prevalent in the North Tongu area and requires the attention of the veterinary and health authorities, using the One‐ Health approach in order to control its occurrence and save lives.

Since 1980, the world has been threatened by different waves of emerging disease epidemics. In the twenty-first century, these diseases have become an increasing global concern because of their health and economic impacts in both developed and resource-constrained countries. It is difficult to stop the occurrence of new pathogens in the future due to the interconnection among humans, animals, and the environment. However, it is possible to face a new disease or to reduce the risk of its spread by implementing better early warning systems and effective disease control and prevention, e.g., effective global surveillance, development of technology for better diagnostics, effective treatments, and vaccines, the global political will to respond to any threats and multidisciplinary collaboration involving all sectors in charge of good health maintenance. In this review, we generally describe some factors related to human activities and show how they can play a role in the transmission and spread of infectious diseases by using some diseases as examples. Additionally, we describe and discuss major factors that are facilitating the spread of the new pandemic known as COVID-19 worldwide.

Yaws is a skin debilitating disease caused by Treponema pallidum subspecies pertenue with most cases reported in children. World Health Organization (WHO) aims at total eradication of this disease through mass treatment of suspected cases followed by an intensive follow-up program. However, effective diagnosis is pivotal in the successful implementation of this control program. Recombinase polymerase amplification (RPA), an isothermal nucleic acid amplification technique offers a wider range of differentiation of pathogens including those isolated from chronic skin ulcers with similar characteristics such as Haemophilus ducreyi (H. ducreyi). We have developed a RPA assay for the simultaneous detection of Treponema pallidum (T. pallidum) and H. ducreyi (TPHD-RPA). The assay demonstrated no cross-reaction with other pathogens and enable detection of T. pallidum and H. ducreyi within 15 min at 42 &deg, C. The RPA assay was validated with 49 clinical samples from individuals confirmed to have yaws by serological tests. Comparing the developed assay with commercial multiplex real-time PCR, the assay demonstrated 94% and 95% sensitivity for T. pallidum and H. ducreyi, respectively and 100% specificity. This simple novel TPHD-RPA assay enables the rapid detection of both T. pallidum and H. ducreyi in yaws-like lesions. This test could support the yaws eradication efforts by ensuring reliable diagnosis, to enable monitoring of program success and planning of follow-up interventions at the community level.

The eradication of yaws caused by Treponema pallidum subsp. pertenue is constrained by the lack of rapid, accurate diagnosis. We sought to develop a molecular point-of-care test for the diagnosis of yaws. A loop-mediated isothermal amplification (LAMP) assay with primers targeting the conserved gene, tp0967, with visual detection by lateral flow test strip was developed and optimized. The limit of detection was evaluated while 63 samples from clinical cases of yaws and five samples with polymerase chain reaction (PCR)–confirmed syphilis were used to determine the sensitivity and specificity of the assay compared with the current molecular testing protocol. The developed LAMP assay was found to be optimal when run at 65°C for 30 minutes. The limit of detection from extracted DNA was 2.7 × 10(4) DNA copies/mL. The sensitivity of the LAMP assay using unextracted and DNA extracted samples were 0.67 and 1.00, respectively. None of the syphilis samples tested positive in any of the assays. We show the development of a fast and sensitive LAMP assay for yaws detected by lateral flow test strip. Using extracted DNA, the assay sensitivity is at par with real-time PCR-based detection. The assay can be adapted to minimal sample processing required for infield detection without DNA extraction.

IntroductionYaws is a neglected tropical disease and results in lesions of skin, soft tissues and bones. PCR plays an important part in surveillance.MethodsChildren suspected to have yaws were enrolled. From the largest lesion paired swabs were collected; one into transport medium and one as a dry swab. In children with multiple lesions we collected additional swabs from up to four subsequent lesions. Swabs in transport medium were maintained in a cold-chain whilst dry swabs were stored at ambient temperature. Swabs were tested by PCR for Treponema pallidum and Haemophilus ducreyi.ResultsOf 55 individuals, 10 (18%) had at least 1 positive PCR for T. pallidum and 12 (22%) had at least 1 positive result for H. ducreyi. Concordance was 100% between swabs in transport medium and dry swabs. One patient had PCR-confirmed yaws on the swab of a third lesion when both the first and second lesions were PCR-negative.DiscussionStoring swabs in transport medium and transporting in a cold chain did not improve yield, however detection of T. pallidum is increased by swabbing additional lesions. As the target for yaws is eradication approaches to sample collection need revisiting to ensure cases are not missed.

Yaws is a neglected tropical disease caused by the bacterium Treponema pallidum subspecies pertenue. The disease primarily affects children under 15 years of age living in low socioeconomic conditions in tropical areas. As a result of a renewed focus on the disease owing to a recent eradication effort initiated by the World Health Organization, we have evaluated a typing method, adapted from and based on the enhanced Centers for Disease Control and Prevention typing method for T. pallidum subsp. pallidum, for possible use in epidemiological studies. Thirty DNA samples from yaws cases in Vanuatu and Ghana, 11 DNA samples extracted from laboratory strains, and 3 published genomic sequences were fully typed by PCR/RFLP analysis of the tpr E, G, and J genes and by determining the number of 60-bp repeats within the arp gene. Subtyping was performed by sequencing a homonucleotide “G” tandem repeat immediately upstream of the rpsA gene and an 84-bp region of tp0548. A total of 22 complete strain types were identified; two strain types in clinical samples from Vanuatu (5q11/ak and 5q12/ak), nine strain types in clinical samples from Ghana (3q12/ah, 4r12/ah, 4q10/j, 4q11/ah, 4q12/ah, 4q12/v, 4q13/ah, 6q10/aj, and 9q10/ai), and twelve strain types in laboratory strains and published genomes (2q11/ae, 3r12/ad, 4q11/ad, 4q12/ad, 4q12/ag, 4q12/v, 5r12/ad, 6r12/x, 6q11/af, 10q9/r, 10q12/r, and 12r12/w). The tpr RFLP patterns and arp repeat sizes were subsequently verified by sequencing analysis of the respective PCR amplicons. This study demonstrates that the typing method for subsp. pallidum can be applied to subsp. pertenue strains and should prove useful for molecular epidemiological studies on yaws.

Introduction The WHO yaws eradication strategy consists of one round of total community treatment (TCT) of single-dose azithromycin with coverage of > 90%.The efficacy of the strategy to reduce the levels on infection has been demonstrated previously in isolated island communities in the Pacific region. We aimed to determine the efficacy of a single round of TCT with azithromycin to achieve a decrease in yaws prevalence in communities that are endemic for yaws and surrounded by other yaws-endemic areas. Methods Surveys for yaws seroprevalence and prevalence of skin lesions were conducted among schoolchildren aged 5–15 years before and one year after the TCT intervention in the Abamkrom sub-district of Ghana. We used a cluster design with the schools as the primary sampling unit. Among 20 eligible primary schools in the sub district, 10 were assigned to the baseline survey and 10 to the post-TCT survey. The field teams conducted a physical examination for skin lesions and a dual point-of-care immunoassay for non-treponemal and treponemal antibodies of all children present at the time of the visit. We also undertook surveys with non-probabilistic sampling to collect lesion swabs for etiology and macrolide resistance assessment. Results At baseline 14,548 (89%) of 16,287 population in the sub-district received treatment during TCT. Following one round of TCT, the prevalence of dual seropositivity among all children decreased from 10.9% (103/943) pre-TCT to 2.2% (27/1211) post-TCT (OR 0.19; 95%CI 0.09–0.37). The prevalence of serologically confirmed skin lesions consistent with active yaws was reduced from 5.7% (54/943) pre-TCT to 0.6% (7/1211) post-TCT (OR 0.10; 95% CI 0.25–0.35). No evidence of resistance to macrolides against Treponema pallidum subsp. pertenue was seen. Discussion A single round of high coverage TCT with azithromycin in a yaws affected sub-district adjoining other endemic areas is effective in reducing the prevalence of seropositive children and the prevalence of early skin lesions consistent with yaws one year following the intervention. These results suggest that national yaws eradication programmes may plan the gradual expansion of mass treatment interventions without high short-term risk of reintroduction of infection from contiguous untreated endemic areas., Author summary In this study, we provided a single round of total community treatment (TCT) with azithromycin to the population of a sub-district in Ghana (16,287 people) that is endemic for yaws and surrounded by other yaws-endemic communities to determine whether a sustained decrease in yaws prevalence could be achieved up to one year after the intervention. The efficacy of TCT was assessed by performing a clinical evaluation and serological testing of any yaws-like lesions found as well as serological screening of asymptomatic schoolchildren aged 5–15 years pre-TCT and at one year post-TCT. The results indicate that after a single round of high coverage TCT (89%) with azithromycin, the prevalence of active and latent yaws was significantly reduced. We also found that the use of a dual point-of-care immunoassay to detect non-treponemal and treponemal antibodies among school-going children is a practical alternative to laboratory-based serological testing to evaluate the effectiveness of yaws interventions in resource-poor settings.

Haemophilus ducreyi causes chancroid and has recently been shown to be a significant cause of cutaneous lesions in tropical or subtropical regions where yaws is endemic. Here, we report the draft genome assemblies for 11 cutaneous strains of Haemophilus ducreyi , isolated from children in Vanuatu and Ghana.