Dengue vector control in high-income, city settings: A scoping review of approaches and methods.

BACKGROUND: Dengue virus (DENV) is endemic to many parts of the world and has serious health and socioeconomic effects even in high-income countries, especially with rapid changes in the climate globally. We explored the literature on dengue vector control methods used in high-income, city settings and associations with dengue incidence, dengue prevalence, or mosquito vector densities. METHODS: Studies of any design or year were included if they reported effects on human DENV infection or Aedes vector indices of dengue-specific vector control interventions in high-income, city settings. RESULTS: Of 24 eligible sources, most reported research in the United States (n = 8) or Australia (n = 5). Biocontrol (n = 12) and chemical control (n = 13) were the most frequently discussed vector control methods. Only 6 sources reported data on the effectiveness of a given method in reducing human DENV incidence or prevalence, 2 described effects of larval and adult control on Aedes DENV positivity, 20 reported effectiveness in reducing vector density, using insecticide, larvicide, source reduction, auto-dissemination of pyriproxyfen and Wolbachia, and only 1 described effects on human-vector contact. CONCLUSIONS: As most studies reported reductions in vector densities, rather than any effects on human DENV incidence or prevalence, we can draw no clear conclusions on which interventions might be most effective in reducing dengue in high-income, city areas. More research is needed linking evidence on the effects of different DENV vector control methods with dengue incidence/prevalence or mosquito vector densities in high-income, city settings as this is likely to differ from low-income settings. This is a significant evidence gap as climate changes increase the global reach of DENV. The importance of community involvement was clear in several studies, although it is impossible to tease out the relative contributions of this from other control methods used.

A pilot study of intraoperative application of cooled radiofrequency to reduce post-operative pain following total knee arthroplasty.

BACKGROUND: Total Knee Arthroplasty (TKA) is a successful treatment for end stage knee osteoarthritis (OA), but can be associated with significant pain in the early post-operative period. Cooled radiofrequency ablation (CRFA) has reported to reduce knee OA pain by targeting the periarticular nerves. The objective of this pilot study was to assess the effectiveness of intra-operative CRFA for reducing pain and opiate use after TKA. METHODS: This was a non randomised prospective study with control group. Participants were sequentially recruited preoperatively and underwent TKA, with CRFA to 6 targeted sites prior to cementing of implants, and were compared to controls who underwent TKA without CRFA. The primary outcome was Day 3 pain scores, and secondary outcomes included week one pain scores, and opiate use up to six weeks post-operative. RESULTS: 17 participants were recruited to the control group and 12 were recruited to the CRFA group. There was no significant difference in demographics or baseline pain scores between the groups. On day 2 the CRFA group had a lower mean pain VAS score of 3.2 compared to 4.4 in the control group (p = 0.03). The mean post operative VAS pain score did not differ between the groups for Day 1, 3, 4, or any other time points up to 6 weeks. There were no significant reduction in opiate use in the CRFA group compared to the control group. There were no adverse events. CONCLUSION: This study demonstrated intra-operative CRFA was not effective in reducing pain by 50% after TKA in a pilot study.

Different mechanisms of X-ray irradiation-induced male and female sterility in Aedes aegypti.

BACKGROUND: Aedes aegypti (Ae. aegypti) is the major vector that transmits many diseases including dengue, Zika, and filariasis in tropical and subtropical regions. Due to the growing resistance to chemical-based insecticides, biological control methods have become an emerging direction to control mosquito populations. The sterile insect technique (SIT) deploys high doses of ionizing radiation to sterilize male mosquitoes before the release. The Wolbachia-based population suppression method of the incompatible insect technique (IIT) involves the release of Wolbachia-infected males to sterilize uninfected field females. Due to the lack of perfect sex separation tools, a low percentage of female contamination is detected in the male population. To prevent the unintentional release of these Wolbachia-infected females which might result in population replacement, a low dose of X-ray irradiation is deployed to sterilize any female escapees. However, it remains unclear whether these irradiation-induced male and female sterilizations share common mechanisms. RESULTS: In this work, we set out to define the minimum dose of X-ray radiation required for complete female sterilization in Ae. aegypti (NEA-EHI strain). Further results showed that this minimum dose of X-ray irradiation for female sterilization significantly reduced male fertility. Similar results have been reported previously in several operational trials. By addressing the underlying causes of the sterility, our results showed that male sterility is likely due to chromosomal damage in the germ cells induced by irradiation. In contrast, female sterility appears to differ and is likely initiated by the elimination of the somatic supporting cells, which results in the blockage of the ovariole maturation. Building upon these findings, we identified the minimum dose of X-ray irradiation on the Wolbachia-infected NEA-EHI (wAlbB-SG) strain, which is currently being used in the IIT-SIT field trial. Compared to the uninfected parental strain, a lower irradiation dose could fully sterilize wAlbB-SG females. This suggests that Wolbachia-carrying mosquitoes are more sensitive to irradiation, consistent with a previous report showing that a lower irradiation dose fully sterilized Wolbachia-infected Ae. aegypti females (Brazil and Mexican strains) compared to those uninfected controls. CONCLUSIONS: Our findings thus reveal the distinct mechanisms of ionizing X-ray irradiation-induced male or female sterility in Ae. aegypti mosquitoes, which may help the design of X-ray irradiation-based vector control methods.

Spatial analyses of Plasmodium knowlesi vectors with reference to control interventions in Malaysia.

BACKGROUND: Malaria parasites such as Plasmodium knowlesi, P. inui, and P. cynomolgi are spread from macaques to humans through the Leucosphyrus Group of Anopheles mosquitoes. It is crucial to know the distribution of these vectors to implement effective control measures for malaria elimination. Plasmodium knowlesi is the most predominant zoonotic malaria parasite infecting humans in Malaysia. METHODS: Vector data from various sources were used to create distribution maps from 1957 to 2021. A predictive statistical model utilizing logistic regression was developed using significant environmental factors. Interpolation maps were created using the inverse distance weighted (IDW) method and overlaid with the corresponding environmental variables. RESULTS: Based on the IDW analysis, high vector abundances were found in the southwestern part of Sarawak, the northern region of Pahang and the northwestern part of Sabah. However, most parts of Johor, Sabah, Perlis, Penang, Kelantan and Terengganu had low vector abundance. The accuracy test indicated that the model predicted sampling and non-sampling areas with 75.3% overall accuracy. The selected environmental variables were entered into the regression model based on their significant values. In addition to the presence of water bodies, elevation, temperature, forest loss and forest cover were included in the final model since these were significantly correlated. Anopheles mosquitoes were mainly distributed in Peninsular Malaysia (Titiwangsa range, central and northern parts), Sabah (Kudat, West Coast, Interior and Tawau division) and Sarawak (Kapit, Miri, and Limbang). The predicted Anopheles mosquito density was lower in the southern part of Peninsular Malaysia, the Sandakan Division of Sabah and the western region of Sarawak. CONCLUSION: The study offers insight into the distribution of the Leucosphyrus Group of Anopheles mosquitoes in Malaysia. Additionally, the accompanying predictive vector map correlates well with cases of P. knowlesi malaria. This research is crucial in informing and supporting future efforts by healthcare professionals to develop effective malaria control interventions.

Is 1:1000 adrenaline as a topical haemostat an effective alternative to control bleeding in dentistry and oral surgery?

Minor oral surgery can give rise to bleeding intra- and post-operatively. This can be minimal in most patients; however, it can be more problematic in patients with impaired clotting disorders, liver disease, or taking any form of anticoagulation therapy. Haemostatic agents are available to overcome such bleeding risks. The topical application of 1:1000 adrenaline used in medicine can be considered for use in dentistry. Adrenaline is widely used within medicine, surgery and dentistry. Examples include its use in local anaesthetic agents, in the management of anaphylaxis and as part of the cardiopulmonary resuscitation algorithm. 1:1000 adrenaline used topically for ear, nose and throat surgeries has shown improved visual fields during surgery with better surgical outcomes. It is relatively safe, but in patients with cardiovascular comorbidities, it should be practised with caution. This has precipitated the idea for its use within oral surgical procedures, including canine exposures, third molar surgery, root displacement into the antrum and periapical surgery. The haemostatic effect of 1:1000 adrenaline as an alternative should be considered in operative dentistry and oral surgery to aid in haemostasis and improve intra-operative visualisation, reducing the risk of iatrogenic damage and bleeding, thereby improving treatment outcomes.

Cryptic Diversity and Demographic Expansion of Plasmodium knowlesi Malaria Vectors in Malaysia.

Although Malaysia is considered free of human malaria, there has been a growing number of Plasmodium knowlesi cases. This alarming trend highlighted the need for our understanding of this parasite and its associated vectors, especially considering the role of genetic diversity in the adaptation and evolution among vectors in endemic areas, which is currently a significant knowledge gap in their fundamental biology. Thus, this study aimed to investigate the genetic diversity of Anopheles balabacensis, Anopheles cracens, Anopheles introlatus, and Anopheles latens-the vectors for P. knowlesi malaria in Malaysia. Based on cytochrome c oxidase 1 (CO1) and internal transcribed spacer 2 (ITS2) markers, the genealogic networks of An. latens showed a separation of the haplotypes between Peninsular Malaysia and Malaysia Borneo, forming two distinct clusters. Additionally, the genetic distances between these clusters were high (2.3-5.2% for CO1) and (2.3-4.7% for ITS2), indicating the likely presence of two distinct species or cryptic species within An. latens. In contrast, no distinct clusters were observed in An. cracens, An. balabacensis, or An. introlatus, implying a lack of pronounced genetic differentiation among their populations. It is worth noting that there were varying levels of polymorphism observed across the different subpopulations, highlighting some levels of genetic variation within these mosquito species. Nevertheless, further analyses revealed that all four species have undergone demographic expansion, suggesting population growth and potential range expansion for these vectors in this region.

High transmission efficiency of the simian malaria vectors and population expansion of their parasites Plasmodium cynomolgi and Plasmodium inui.

BACKGROUND: The elimination of malaria in Southeast Asia has become more challenging as a result of rising knowlesi malaria cases. In addition, naturally occurring human infections with other zoonotic simian malaria caused by Plasmodium cynomolgi and Plasmodium inui adds another level of complexity in malaria elimination in this region. Unfortunately, data on vectors which are responsible for transmitting this zoonotic disease is very limited. METHODOLOGY/PRINCIPAL FINDINGS: We conducted longitudinal studies to investigate the entomological parameters of the simian malaria vectors and to examine the genetic diversity and evolutionary pattern of their simian Plasmodium. All the captured Anopheles mosquitoes were dissected to examine for the presence of oocysts, sporozoites and to determine the parous rate. Our study revealed that the Anopheles Leucosphyrus Group mosquitoes are highly potential competent vectors, as evidenced by their high rate of parity, survival and sporozoite infections in these mosquitoes. Thus, these mosquitoes represent a risk of human infection with zoonotic simian malaria in this region. Haplotype analysis on P. cynomolgi and P. inui, found in high prevalence in the Anopheles mosquitoes from this study, had shown close relationship between simian Plasmodium from the Anopheles mosquitoes with its vertebrate hosts. This directly signifies the ongoing transmission between the vector, macaques, and humans. Furthermore, population genetic analysis showed significant negative values which suggest that both Plasmodium species are undergoing population expansion. CONCLUSIONS/SIGNIFICANCE: With constant microevolutionary processes, there are potential for both P. inui and P. cynomolgi to emerge and spread as a major public health problem, following the similar trend of P. knowlesi. Therefore, concerted vector studies in other parts of Southeast Asia are warranted to better comprehend the transmission dynamics of this zoonotic simian malaria which eventually would aid in the implementation of effective control measures in a rapidly changing environment.

Profiling the imported human malaria in Sarawak, Malaysia in 2011-2019.

OBJECTIVES: Malaysia has achieved the status of zero indigenous human malaria cases. Nevertheless, imported human malaria has increasingly been reported in Sarawak, Malaysian Borneo. As zoonotic malaria caused by Plasmodium knowlesi remains a major public health problem in Sarawak, the threat of imported malaria must be addressed as it can cause human malaria reintroduction, sustain transmission, and lead to complications. The objectives of this study were to investigate the epidemiological characteristics of imported malaria cases reported in Sarawak and to underline the challenge posed by imported malaria towards malaria elimination efforts. METHODS: Imported malaria cases reported in Sarawak from 2011 to 2019 were collected from Sarawak State Health Department and analysed in this longitudinal retrospective study. RESULTS: A total of 2058 imported malaria cases were registered in all districts in Sarawak. Highest number of cases were reported in Kapit (n = 559; 27.16%), followed by Sibu (n = 424; 20.6%), and Miri (n = 166; 8.07%). Based on the demographic profile, most of the patients constituted of either male sex (98.49%), age group of 40-49 years (39.6%), Iban ethnic (57.92%), worked in logging industry (88.58%), Malaysian nationals (91.84%), contracted malaria in Papua New Guinea (46.11%), uncomplicated disease (77.89%), or hospitalised cases (97.86%). The most prominent Plasmodium species diagnosed were P. vivax (52.67%) and P. falciparum (35.81%). CONCLUSIONS: Surveillance, disease detection, and medical follow-up must be carried out thoroughly for individuals who returned from malaria-endemic countries. It is also necessary to promote pre-travel preventive education as well as chemoprophylaxis to travellers heading to endemic areas.

Epidemiology of indigenous Plasmodium knowlesi infection in Sarawak, 2011-2019.

OBJECTIVES: To characterise the state-wide epidemiology of indigenous knowlesi malaria in Sarawak from 2011 to 2019. METHODS: Longitudinal retrospective study was conducted based on Sarawak knowlesi malaria surveillance data recorded from 2011-2019. Only indigenous cases were included and information extracted for analysis comprised age, sex, occupation, ethnicity, case severity, hospital admission and parasite density. RESULTS: Over the 9 years, 8473 indigenous knowlesi malaria cases were recorded. Age group 40-49 years, males, plantation workers and Iban communities recorded the highest percentage of cases in each demographic variable. Most of the cases were uncomplicated (n = 7292; 86.1%) and 89.6% (n = 7589) of the total cases were reported with ≤20 000 parasites/µl of blood. Age group and ethnic group are associated with the severity of knowlesi malaria in Sarawak. Multivariable logistic regression indicated that the age group 60+ years had the highest odds of developing severe knowlesi malaria compared with other age groups (AOR 2.48; 95% CI 1.22, 5.02; p = 0.012). Bidayuh patients were more likely to develop severe knowlesi malaria than Ibans, the largest ethnic group among knowlesi malaria patients (AOR 1.97; 95% CI 1.31, 2.97; p = 0.001). CONCLUSIONS: Identification of risk groups is important for the implementation of prevention programs and treatments targeting at specific group to combat knowlesi malaria effectively.

Correction: Pramasivan et al. Multiplex PCR Assay for the Identification of Four Species of the Anopheles Leucosphyrus Sub-Group in Malaysia. Insects 2022, 13, 195.

In the original publication [...].

Retrospective audit of midazolam dose and intravenous sedation record keeping in a primary care oral surgery service.

Regular and robust audit of conscious sedation practice is key to the delivery of safe and effective patient care in all clinical settings. Analysis of outcomes will help to highlight any necessary modifications to procedures and techniques. The Intercollegiate Advisory Committee for Sedation in Dentistry (IACSD) states that conscious sedation procedures must be the subject of robust and regular audit in which every member within the team takes part.1 This completed audit cycle highlighted the efficacy of intravenous (IV) midazolam in anxious patients undergoing oral surgical procedures and the suitability for its use in the primary care setting. No patient safety concerns or complications were recorded in this audit and midazolam was administered within the recommended dose range. By the conclusion of two audit cycles, all clinicians providing intravenous sedation within the service were aware of the missing elements in sedation record-keeping and were able to complete accurate contemporaneous records before, during and after conscious sedation, ensuring the continuous delivery of high-quality, safe, and patient-centred care.

Oral cancer diagnosis amid COVID-19 pandemic: Identifying tell-tale signs to avoid pitfalls in general dental practice.

This article details the unusual presentation of an oral squamous cell carcinoma (SCC) referred to secondary care during the COVID-19 pandemic. The patient's chief complaints were trismus and pain from a lower left partially erupted third molar, which was assumed to be pericoronitis-related on referral. Intra-oral examination was difficult due to the patient's symptoms, but radiographic assessment of an orthopantomogram (OPG) showed a pathological fracture and poorly defined radiolucency in the lower left third molar region. Oral SCC was diagnosed after biopsy, and surgery and radiotherapy were swiftly carried out despite COVID-19 restrictions. General dental practitioners (GDPs) remain the frontline healthcare professionals in the screening and detection of oral cancer through detailed history taking and examinations. Primary care dental practitioners should always remain vigilant with patients at risk of oral cancer. Prompt referral to secondary care for further investigations and management should be made when a suspicion of oral malignancy is raised, to ensure a better treatment outcome. Video consultations have had their merits in dentistry amid the coronavirus pandemic, but face-to-face consultations are essential to establish quality patient care.

Multiplex PCR Assay for the Identification of Four Species of the Anopheles Leucosphyrus Sub-Group in Malaysia.

The Leucosphyrus Group of mosquitoes are the major simian malaria vectors in Malaysia. Accurate species identification is required to help in curbing the spread of simian malaria. The aim of the study is to provide an accurate molecular method for identifying the four important Anopheles vector species found in Malaysia. Mosquito specimens were collected from various localities in Malaysia, where simian malaria cases were reported. DNA from 122 mosquito specimens was tested to develop a multiplex polymerase chain reaction (PCR) assay. The specificity of this assay was tested against other mosquito species. Molecular identification of the species was further confirmed by analysing the internal transcribed spacer 2 (ITS2) DNA region of the specimens. Anopheles balabacensis and An. latens showed two distinct clades in the phylogenetic tree. The multiplex PCR assay was developed based on the ITS2 region for the identification of Anopheles introlatus (298-299 bp), Anopheles latens (197-198 bp), Anopheles cracens (421-426 bp), and Anopheles balabacensis (224-228 bp). This method will be useful to accurately identify the major Anopheles Leucosphyrus Group species in Malaysia, which are difficult to identify morphologically, to determine the correct vector as well as its geographical distribution.

Blood meal analysis of Anopheles vectors of simian malaria based on laboratory and field studies.

Blood feeding and host-seeking behaviors of a mosquito play an imperative role in determining its vectorial capacity in transmitting pathogens. Unfortunately, limited information is available regarding blood feeding behavior of Anopheles species in Malaysia. Collection of resting Anopheles mosquitoes for blood meal analysis poses a great challenge especially for forest dwelling mosquitoes. Therefore, a laboratory-based study was conducted to evaluate the potential use of mosquitoes caught using human landing catch (HLC) for blood meal analysis, and subsequently to document blood feeding behavior of local Anopheles mosquitoes in Peninsular Malaysia. The laboratory-based experiment from this study revealed that mosquitoes caught using HLC had the potential to be used for blood meal analysis. Besides HLC, mosquitoes were also collected using manual aspirator and Mosquito Magnet. Overall, 47.4% of 321 field-caught Anopheles mosquitoes belonging to six species were positive for vertebrate host DNA in their blood meal. The most frequent blood meal source was human (45.9%) followed by wild boar (27.4%), dog (15.3%) and monkey (7.5%). Interestingly, only Anopheles cracens and Anopheles introlatus (Leucosphyrus Group) fed on monkey. This study further confirmed that members of the Leucosphyrus Group are the predominant vectors for knowlesi malaria transmission in Peninsular Malaysia mainly due to their simio-anthropophagic feeding behavior.

Dengue surveillance using gravid oviposition sticky (GOS) trap and dengue non-structural 1 (NS1) antigen test in Malaysia: randomized controlled trial.

Dengue remains a major public threat and existing dengue control/surveillance programs lack sensitivity and proactivity. More efficient methods are needed. A cluster randomized controlled trial was conducted for 18 months to determine the efficacy of using a combination of gravid oviposition sticky (GOS) traps and dengue non-structural 1 (NS1) antigen for early surveillance of dengue among Aedes mosquito. Eight residential apartments were randomly assigned into intervention and control groups. GOS traps were placed at the intervention apartments weekly to trap Aedes mosquitoes and these tested for dengue NS1 antigen. When dengue-positive pool was detected, the community were notified and advised to execute protective measures. Fewer dengue cases were recorded in the intervention group than the control. Detection of NS1-positive mosquitoes was significantly associated with GOS Aedes index (rs = 0.68, P < 0.01) and occurrence of dengue cases (rs = 0.31, P < 0.01). Participants' knowledge, attitude, and practice (KAP) toward dengue control indicated significant improvement for knowledge (P < 0.01), practice (P < 0.01) and total scores (P < 0.01). Most respondents thought this surveillance method is good (81.2%) and supported its use nationwide. Thus, GOS trap and dengue NS1 antigen test can supplement the current dengue surveillance/control, in alignment with the advocated integrated vector management for reducing Aedes-borne diseases.

Clinical decision-making in complex endodontic cases between postgraduate students across dental specialties at a UK dental school: A pilot study.

INTRODUCTION: Treatment decisions for a heavily restored endodontically treated tooth vary amongst clinicians owing to multitude of factors. This phenomenon not only often poses dilemmas to clinicians of different clinical backgrounds, but also exerts a degree of treatment difficulty to the treating clinician. Previous studies indicated that specialty training and clinical experience significantly impacted clinical decision-making process. MATERIALS AND METHODS: Master of Science postgraduate students in endodontics, prosthodontics, periodontics, oral surgery and implantology participated in a questionnaire-based cross-sectional study. The dental specialties were further categorised into restorative and surgical dentistry. A multiple-choice questionnaire with three clinical cases was distributed to the students. Data were analysed for trends using descriptive statistics. RESULTS: There was a 44% response rate; the majority of respondents were from restorative dentistry specialties. Cases 1 and 2 were rated as moderate to high difficulty, and Case 3 was predominantly rated as high difficulty with procedure predictability being the main factor affecting their clinical decision-making in three cases. Endodontic retreatment was selected as the preferred treatment in Cases 1 and 2 and periradicular surgery in Case 3. The students were fairly confident in managing Cases 1 and 2, but not in Case 3. Referral patterns were consistent in Cases 1 and 2 with endodontists being the first choice of referral except for Case 3 where 48% preferred to refer to oral surgeons and 35% choosing endodontists. Some indication of differences between specialties were noted throughout. Years in practice appeared to be related to the importance of predictability in Case 3 only. CONCLUSION: Considerable inter-clinician variability was noted whereby specialty postgraduate training impacted on clinical decision-making. Overall, procedural predictability, technical difficulty, risk of damage to the tooth and patient preference were the most highly ranked factors affecting clinical decision-making. Evidence-based treatment guidelines and dental curricula should be reviewed to enhance inter-clinician agreement in clinical decision-making, ultimately improving patient care.

The vectors of Plasmodium knowlesi and other simian malarias Southeast Asia: challenges in malaria elimination.

Plasmodium knowlesi, a simian malaria parasite of great public health concern has been reported from most countries in Southeast Asia and exported to various countries around the world. Currently P. knowlesi is the predominant species infecting humans in Malaysia. Besides this species, other simian malaria parasites such as P. cynomolgi and P. inui are also infecting humans in the region. The vectors of P. knowlesi and other Asian simian malarias belong to the Leucosphyrus Group of Anopheles mosquitoes which are generally forest dwelling species. Continual deforestation has resulted in these species moving into forest fringes, farms, plantations and human settlements along with their macaque hosts. Limited studies have shown that mosquito vectors are attracted to both humans and macaque hosts, preferring to bite outdoors and in the early part of the night. We here review the current status of simian malaria vectors and their parasites, knowledge of vector competence from experimental infections and discuss possible vector control measures. The challenges encountered in simian malaria elimination are also discussed. We highlight key knowledge gaps on vector distribution and ecology that may impede effective control strategies.

Spatial distribution of Plasmodium knowlesi cases and their vectors in Johor, Malaysia: in light of human malaria elimination.

BACKGROUND: Plasmodium knowlesi, a simian malaria parasite infection, increases as Plasmodium falciparum and Plasmodium vivax infections decrease in Johor, Malaysia. Therefore, this study aimed to identify the distribution of vectors involved in knowlesi malaria transmission in Johor. This finding is vital in estimating hotspot areas for targeted control strategies. METHODS: Anopheles mosquitoes were collected from the location where P. knowlesi cases were reported. Cases of knowlesi malaria from 2011 to 2019 in Johor were analyzed. Internal transcribed spacers 2 (ITS2) and cytochrome c oxidase subunit I (COI) genes were used to identify the Leucosphyrus Group of Anopheles mosquitoes. In addition, spatial analysis was carried out on the knowlesi cases and vectors in Johor. RESULTS: One hundred and eighty-nine cases of P. knowlesi were reported in Johor over 10 years. Young adults between the ages of 20-39 years comprised 65% of the cases. Most infected individuals were involved in agriculture and army-related occupations (22% and 32%, respectively). Four hundred and eighteen Leucosphyrus Group Anopheles mosquitoes were captured during the study. Anopheles introlatus was the predominant species, followed by Anopheles latens. Spatial analysis by Kriging interpolation found that hotspot regions of P. knowlesi overlapped or were close to the areas where An. introlatus and An. latens were found. A significantly high number of vectors and P. knowlesi cases were found near the road within 0-5 km. CONCLUSIONS: This study describes the distribution of P. knowlesi cases and Anopheles species in malaria-endemic transmission areas in Johor. Geospatial analysis is a valuable tool for studying the relationship between vectors and P. knowlesi cases. This study further supports that the Leucosphyrus Group of mosquitoes might be involved in transmitting knowlesi malaria cases in Johor. These findings may provide initial evidence to prioritize diseases and vector surveillance.

Natural Plasmodium inui Infections in Humans and Anopheles cracens Mosquito, Malaysia.

We detected 2 natural, asymptomatic Plasmodium inui monoinfections in humans in Malaysia by using nested PCR on concentrated high-volume blood samples. We found a P. inui-positive Anopheles cracens mosquito in the same site as the human infections. Investigators should use ultrasensitive detection methods to identify simian malaria parasite transmission in humans.