Entomological survey and report of a knockdown resistance mutation in the malaria vector Anopheles gambiae from the Republic of Guinea

The purpose of our entomological survey was to estimate mosquito biodiversity, infectivity rates and insecticide resistance levels in Anopheles species in four study sites in a mining area with high malaria transmission in southeastern Guinea. Anopheles gambiae s.l. (77%) was the most common Anopheles collected followed by An. funestus (20%). The specimens of the An. gambiae complex were predominantly An. gambiae S form (97.6%) with 1.4% of An. gambiae M form found in Kérouané only, and 1% of An. arabiensis which was present in all four study sites. Anopheles gambiae S form and An. funestus were found to be infected with Plasmodium falciparum, with infectivity rates of 4.1% and 4.4% and inoculation rates of 0.60 and 0.19 infected bite/person/night, respectively. In addition, a high level (79%) of the knockdown resistance (kdr) L1014F mutation was reported in the populations of An. gambiae S form. The high malaria transmission that occurs in the prospected area of Guinea requires a long-term vector control programme. However, such a control programme will have to consider the presence of the kdr gene at a surprisingly high level within the dominant vector, which could reduce the expected impact of vector control.     

The Lys-76-Thr mutation in PfCRT and chloroquine resistance in Plasmodium falciparum isolates from Uganda

Recent molecular studies of chloroquine (CQ) resistance of Plasmodium falciparum have demonstrated an association between a mutation in the PfCRT gene and CQ resistance. We identified wild type and mutant alleles of the PfCRT codon 76 in baseline pre-CQ treatment P. falciparum isolates collected during 1999 and investigated their relationship to CQ efficacy in 3 different sites with different levels of CQ parasite resistance in Uganda. Of 32 isolates from Mulago Hospital, all were mutant (100%), while of 45 isolates from Tororo, 5 (11%) were mixed wild type and mutant and 40 (89%) were mutants only. Of 41 isolates from Apac, 13 (32%) were mixed wild type and mutant whereas 28 (68%) were mutants only. The finding of 100% prevalence of the Thr-76 mutant allele in all isolates at the 3 sites was remarkable. We found no association between the presence of Thr-76 mutation and treatment outcome at all the sites. However, the prevalence of the wild-type Lys-76 allele was higher in Apac, an area with lower CQ parasite resistance, compared to Tororo and Mulago which have relatively higher CQ parasite resistance. The Thr-76 allele as a marker of CQ resistance is probably useful in regions where the allele frequency has not yet plateaued.     

The transmission dynamics of bancroftian filariasis: the distribution of the infective larvae of Wuchereria bancrofti in Culex quinquefasciatus and Anopheles gambiae and its effect on parasite escape from the vector

The anatomical distribution of the infective larvae (L3) of Wuchereria bancrofti in Culex quinquefasciatus and Anopheles gambiae, and its influence on L3 escape, was evaluated by exposing the vectors to human individuals infected with W. bancrofti. After the extrinsic incubation period of W. bancrofti, a random sample of the infected mosquitoes was dissected to determine the distribution of infective larvae in the body of the mosquitoes and the proportion of mosquitoes that were infected. The remaining mosquitoes were exposed to an experimental definitive host (mouse skin). The infective larvae on and in the host tissues were counted. The engorged mosquitoes were dissected to determine the proportion infected and the distribution of L3 in mosquitoes after exposure. The results show that 53.4% of L3 escaped from Cx. quinquefasciatus to enter the experimental host whereas only 4% of L3 escaped from An. gambiae. Analysis of the results indicates that the number of L3 in the vector and the proportion of L3 in the head and mouthparts influence the number of L3 escaping from the vector to enter the definitive host and consequently the number that gain access to host tissues. The implication of these findings on the transference of the parasite from the vector to the definitive host is discussed.     

Host feeding preferences of Anopheles species collected by manual aspiration,mechanical aspiration,and from a vehicle-mounted trap in the Toledo District,Belize, Central America

The host-feeding patterns of Anopheles albimanus, Anopheles vestitipennis, and Anopheles punctimacula from the Toledo District in southern Belize were studied with blood-fed females that were collected by manual aspiration, a backpack aspirator, and a vehicle-mounted trap for sampling in-flight mosquito populations. Female An. vestitipennis collected from both inside and outside house walls by manual aspiration tested positive for human blood meals (88 and 67%, respectively). At increasing distances from the houses, specimens of An. vestitipennis collected from vegetation with the backpack aspirator were equally positive for human and cattle blood (44 and 43%, respectively). In contrast, 68% of the An. albimanus specimens (148) collected by backpack aspiration tested positive for cattle blood. Engorged An. vestitipennis from vehicle-mounted trap collections tested positive for cattle (108) and human (52) blood. Almost all specimens of An. albimanus from these collections were positive for cow (95%). After analyzing the data from the An. vestitipennis samples using the feeding index, the ratio of human blood to all other bloodmeal sources showed indices greater than 1. Both An. albimanus and An. punctimacula fed mostly on cattle and rarely fed on humans. Foraging ratios for the 3 Anopheles species were very similar to the feeding indexes. Ratios based on data from all collection methods showed that An. vestitipennis feeds predominately on humans. The foraging ratios for An. albimanus demonstrated consistent preferences for nonhuman hosts. As with previous studies. An. albimanus seemed to prefer cattle and pigs to almost all other host species.     

Molecular detection of a novel Babesia sp. and pathogenic spotted fever group rickettsiae in ticks collected from hedgehogs in Turkey: Haemaphysalis erinacei,a novel candidate vector for the genus Babesia

In this study, a total of 319 ticks were obtained from hedgehogs (Erinaceus concolor). All ticks were pooled into groups and screened by PCR for tick-borne pathogens (TBPs). PCR and sequence analyses identified the presence of a novel Babesia sp. in adult Haemaphysalis erinacei. In addition, the presence of natural transovarial transmission of this novel Babesia sp. was detected in Ha. erinacei. According to the 18S rRNA (nearly complete) and partial rRNA locus (ITS-1/5.8S/ITS-2) phylogeny, it was determined that this new species is located within the Babesia sensu stricto clade and is closely related to Babesia spp. found in carnivores. Furthermore, the presence of three pathogenic spotted fever group (SFG) rickettsiae was determined in 65.8% of the tick pools: Rickettsia sibirica subsp. mongolitimonae in Hyalomma aegyptium (adult), Hyalomma spp. (larvae), Rhipicephalus turanicus (adult), and Ha. erinacei (adult); Rickettsia aeschlimannii in H. aegyptium (adult); Rickettsia slovaca in Hyalomma spp. (larvae and nymphs) and H. aegyptium (adult). To our knowledge, this is the first report of R. sibirica mongolitimonae in H. aegyptium, Ha. erinacei, and Rh. turanicus, and the first report of R. slovaca in H. aegyptium. In addition, the presence of a single Hemolivia mauritanica haplotype was detected in H. aegyptium adults. Consequently, the presence of a novel Babesia sp. has been identified in a new candidate vector tick species in this study. Additionally, three SFG rickettsiae that cause infections in humans were identified in ticks collected from hedgehogs. Therefore, environmental wildlife monitoring for hedgehogs should be carried out for ticks and tick-borne pathogens in the region. Additionally, studies regarding the reservoir status of hedgehogs for the aforementioned pathogens must be carried out.     

广州地区急性腹泻患儿粪便中多重耐药及高毒力肺炎克雷伯菌分布检测

目的 了解广州地区急性腹泻患儿粪便中肺炎克雷伯菌的携带情况,以及其中具有多重耐药性和高毒力的肺炎克雷伯菌菌株的分布情况。方法 2015年5~9月,采集广州市某医院门诊腹泻患儿的粪便样本,分离鉴定肺炎克雷伯菌并进行药敏试验,同时筛检产超广谱β-内酰胺酶（extended-spectrum β-lactamases,ESBLs）菌株。采用聚合酶链式反应（polymerase chain reaction,PCR）实验检测产ESBLs菌株中具有耐药基因bla_TEM、bla_SHV和bla_CTX-M的菌株分布情况;用PCR实验检测所有分离菌株中六种常见高毒力荚膜血清型的分布情况。结果 在87份腹泻患儿粪便样本中,肺炎克雷伯菌检出率为66.7%。分离株对青霉素类抗菌药物、第一代头孢菌素和呋喃妥因的耐药率较高;而对二、三、四代头孢类抗菌素、喹诺酮类、氨基糖苷类抗生素耐药性较低,且未检出耐碳青霉烯肺炎克雷伯菌;产ESBLs肺炎克雷伯菌检出率为12.1%（7/58）,其中检出4株bla_CTX-M和2株bla_TEM基因型菌株,未检出含bla_SHV基因型菌株;所有分离株的多重耐药率为27.6%。共检出高毒力肺炎克雷伯菌K2、K20、K54型各1株,未检出K1、K5及K57型。结论 腹泻患儿粪便中肺炎克雷伯菌分离率较高,多重耐药性菌株比例较高,而且存在具有多重耐药同时高毒力的菌株,应引起重视。     

中国内地2016—2022年浴池男男性行为者HIV感染率Meta分析

目的 对2016—2022年中国内地浴池男男性行为者（MSM）HIV感染率进行系统的评价。方法 检索中国知网数据库（CNKI）、万方数据库、中国生物医学文献数据库（CBM）、维普数据库、PubMed、Web of Science和Embase数据库中从2016年1月—2022年1月发表的所有相关研究并进行筛选,使用Stata 17.0软件对纳入的文献进行meta分析。结果 研究共纳入12篇文献,浴池型MSM的合并HIV感染率为8.7%（95%CI:7.3%～10.1%）。亚组分析显示:30岁以下浴池MSM的合并HIV感染率为6.8%,略高于30岁以上的6.1%;随着调查样本量增大,合并HIV感染率从13.6%降低至7.2%;通过场所招募检测得到的合并HIV感染率为8.3%,低于其他抽样方式检测得到的合并HIV感染率（9.7%）;2016年1月之前开展的人群横断面调查合并HIV感染率为9.9%,高于2016年1月之后的合并HIV感染率（8.1%）;西南地区的合并HIV感染率最高,为12.0%;一线城市的合并HIV感染率为9.8%,高于非一线城市合并HIV感染率（7.5%）。研究未发现明显发表偏倚。结论 近六年,我国内地浴池MSM的合并HIV感染率虽有下降,但仍显著高于我国2001—2018年MSM的合并HIV感染率,应继续加强浴池MSM的艾滋病干预。     

Theory and practice of waiting time data as a performance indicator in health care. A case study from The Netherlands

In this article we investigate the use of waiting time data as a performance indicator in health care in The Netherlands. We explain why the current publication of waiting time data fails to achieve one of the main goals: to have consumers and general practitioners act upon this information. The reason, we claim, is that even seemingly clear-cut, easily measurable and objective numbers such as waiting times need interpretation to become meaningful. Discussing four themes - the patient behind the number, the treatment behind the number, the strategy behind the number, and the specificity of the number - we will discuss just how deeply this need for interpretation affects the usability of 'waiting times' for purposes such as informing consumers. We will argue that this problem is due to not making a clear distinction between performance indicators for internal use and for external use. We conclude that the usefulness of the publication of waiting time data for consumers strongly increases when waiting times are guaranteed and related to treatment options like booking possibilities and other performance indicators such as patient satisfaction.     

The bovine viral diarrhea virus E2 protein formulated with a novel adjuvant induces strong,balanced immune responses and provides protection from viral challenge in cattle

Bovine viral diarrhea virus (BVDV) is still one of the most serious pathogens in cattle, meriting the development of improved vaccines. Recently, we developed a new adjuvant consisting of poly[di(sodium carboxylatoethylphenoxy)]-phosphazene (PCEP), either CpG ODN or poly(I:C), and an immune defense regulator (IDR) peptide. As this adjuvant has been shown to mediate the induction of robust, balanced immune responses, it was evaluated in an E2 subunit vaccine against BVDV in lambs and calves. The BVDV type 2 E2 protein was produced at high levels in a mammalian expression system and purified. When formulated with either CpG ODN or poly(I:C), together with IDR and PCEP, the E2 protein elicited high antibody titers and production of IFN-γ secreting cells in lambs. As the immune responses were stronger when poly(I:C) was used, the E2 protein with poly(I:C), IDR and PCEP was subsequently tested in cattle. Robust virus neutralizing antibodies as well as cell-mediated immune responses, including CD8⁺ cytotoxic T cell (CTL) responses, were induced. The fact that CTL responses were demonstrated in calves vaccinated with an E2 protein subunit vaccine indicates that this adjuvant formulation promotes cross-presentation. Furthermore, upon challenge with a high dose of virulent BVDV-2, the vaccinated calves showed almost no temperature response, weight loss, leukopenia or virus replication, in contrast to the control animals, which had severe clinical disease. These data suggest that this E2 subunit formulation induces significant protection from BVDV-2 challenge, and thus is a promising BVDV vaccine candidate; in addition, the adjuvant platform has applications in bovine vaccines in general.