Helicobacter pylori Infection: A 40-Year Journey through Shifting the Paradigm to Transforming the Management.

BACKGROUND: Helicobacter pylori (H. pylori) was discovered 40 years ago and has set a milestone in human medicine. The discovery led to rejection of the dogma of the acidic stomach as a sterile organ and requested to rewrite the chapters on gastric pathophysiology and gastroduodenal diseases. SUMMARY: Over a period of 40 years following the discovery, more than 50,000 articles can be retrieved in PubMed as of today and illustrate the amount and the intensity of research around the role of this bacterium. H. pylori emerged as cause of chronic gastritis and principal cause of peptic ulcer disease (PUD). Eradication of H. pylori became standard of care in management in PUD. The importance of this was highlighted in 2005 with the Nobel Prize in Medicine awarded to Barry Marshall and Robin Warren. H. pylori became eventually recognized for its oncogenic potential in the stomach and as the main risk factor for gastric cancer development. KEY MESSAGES: H. pylori gastritis is defined as infectious disease and requires therapy in all infected individuals. Strategies of gastric cancer prevention and development of therapies to overcome the increasing antibiotic resistance are main targets in clinical research of today.

Potassium-competitive Acid Blockers: Current Clinical Use and Future Developments.

PURPOSE OF THE REVIEW: Acid suppression with proton pump inhibitors (PPIs) represents the standard of care in the treatment of acid-related diseases. However, despite their effectiveness, PPIs display some intrinsic limitations, which underlie the unmet clinical needs that have been identified over the past decades. The aims of this review are to summarize the current status and future development of the new class of antisecretory drugs (potassium-competitive acid blockers, P-CABs) that have recently been introduced into medical practice. RECENT FINDINGS: Over the past decades, clinical needs unmet by the current acid suppressants have been recognized, especially in the management of patients with GERD, Helicobacter pylori infection and NSAID-related peptic ulcer. The failure to address these needs is mainly due to their inability to achieve a consistent acid suppression in all patients and, particularly, to control nighttime acidity. It was then realized that an extended duration of acid suppression would exert additional benefits. The available data with P-CABs show that they are able to address these unmet clinical needs. Four different P-CABs (vonoprazan, tegoprazan, fexuprazan and keverprazan) are currently available. However, only two of them are approved outside Asia. Vonoprazan is available in North, Central and South America while tegoprazan is marketed only in Latin American countries. Two other compounds (namely linazapran glurate and zestaprazan) are presently under clinical development. While clinical trials on GERD have been performed with all P-CABs, only vonoprazan and tegoprazan have been investigated as components of Helicobacter pylori eradication regimens. The available data show that-in the above two clinical indications-P-CABs provide similar or better efficacy in comparison with PPIs. Their safety in the short-term overlaps that of PPIs, but data from long-term treatment are needed.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report.

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

COVID-19 and Gastrointestinal Disease: Implications for the Gastroenterologist.

BACKGROUND: COVID-19 was initially considered a respiratory disease but the SARS-CoV-2 virus can lead to serious systemic consequences affecting major organs including the digestive system. SUMMARY: This review brings new clinically important information for the gastroenterologist. This includes: the mechanisms of tissue damage seen with the SARS-CoV-2 virus; the consequences of immunosuppression in patients with inflammatory bowel disease (IBD) and chronic liver disease with the additional risks of decompensation in patients with cirrhosis; the impact of COVID-19 on gastrointestinal emergencies, on gastrointestinal endoscopy, diagnosis and treatments. These highlight the need to understand the clinical pharmacology, toxicology and therapeutic implications of drugs commonly used by gastroenterologists and their links with COVID-19. Key Messages: Any part of the digestive system may be affected by the SARS-CoV-2 virus, and those with pre-existing disease are at greatest risk of adverse outcomes. The risk for drug-drug interactions is considerable in patients seriously ill with COVID-19 who often require mechanical ventilation and life support. Some repurposed drugs used against SARS-CoV-2 can cause or aggravate some of the COVID-19-related gastrointestinal symptoms and can also induce liver injury. Ongoing clinical studies will hopefully identify effective drugs with a more favourable risk-benefit ratio than many initially tried treatments.

The potential role of potassium-competitive acid blockers in the treatment of gastroesophageal reflux disease.

PURPOSE OF REVIEW: Gastroesophageal reflux disease (GERD) is primarily a motor disorder, but its pathogenesis is multifactorial. Although gastric acid secretion is usually normal in GERD patients, treatment with proton pump inhibitors (PPIs) has become the standard of care, despite increasing awareness of their shortcomings. In this article, a new class of antisecretory drugs (namely potassium-competitive acid blockers, P-CABs), developed to overcome these limitations, is discussed. RECENT FINDINGS: P-CABs block the K exchange channel of the proton pump, resulting in rapid, competitive, reversible inhibition of acid secretion. These drugs offer a more rapid elevation of intragastric pH than PPIs, while maintaining similar antisecretory effect, the duration of which is dependent on half-life and can be prolonged with extended release formulations. Thus, P-CABs offer advances in the treatment of GERD including rapid heartburn relief, faster and more reliable healing of severe grades of erosive esophagitis, as a consequence of better control of nighttime acid secretion than PPIs. SUMMARY: P-CABs overcome many of the drawbacks of PPIs. The unique antisecretory effects of vonoprazan might be especially useful in the long-term treatment of patients with Barrett's esophagus.

Effect of Aspirin and ibuprofen either alone or in combination on gastric mucosa and bleeding time and on serum prostaglandin E2 and thromboxane A2 levels in the anaesthetized rats in vivo.

There is much evidence that a combination of ibuprofen (IBU) and Aspirin (ASA) can antagonize the irreversible inhibition of platelet function. This study was designed to investigate the degree of gastric damage, bleeding time (BT) and fluctuations in the serum levels of prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) after oral administration of ASA (200 mg/kg) and IBU (50 mg/kg) either alone or in combination in rats in vivo. The stomach was assessed for any damage either after 6 h, 18 h or 6 days and carboxymethylcellulose (1% CMC) served as a vehicle and control. ELISA was used to measure TXA2 and PGE2 in serum. Bleeding time was assessed using tail blood. The results show that ASA and IBU either alone or in combination can cause gastric ulceration in 25-100% of the rats at 6 and 18 h. In contrast, gastric ulceration was seen in 50% of rats with a combination of ASA given before IBU only after 6 days of oral administration. BT was unaffected either by ASA or IBU when administered alone except after 18 h for IBU. In contrast, BT was significantly reduced when IBU was administered before ASA after 18 h and 6 days (P < 0.001). Serum PGE2 levels decreased significantly after ASA administered either alone or in combination with IBU for 6 h, 18 h and 6 days (P < 0.05). Serum TXA2 levels were significantly reduced after 6 h, 18 h and 6 days following ASA and IBU administration except for IBU alone which caused a significant increase in serum TXA2 6 days after its administration (P < 0.01). It can be concluded that ASA and IBU administered either alone or in combination can cause gastric ulcers in the rat stomach after 6 h and 18 h, but less severe after 6 days. IBU either alone or in combination with ASA reduced BT only after 18 h and 6 days of administration. Together, the results show that gastric ulceration correlated well with the inhibition of serum PGE2 and TXA2 levels.

The impact of temperature on insecticide toxicity against the malaria vectors Anopheles arabiensis and Anopheles funestus.

BACKGROUND: It is anticipated that malaria elimination efforts in Africa will be hampered by increasing resistance to the limited arsenal of insecticides approved for use in public health. However, insecticide susceptibility status of vector populations evaluated under standard insectary test conditions can give a false picture of the threat, as the thermal environment in which the insect and insecticide interact plays a significant role in insecticide toxicity. METHODS: The effect of temperature on the expression of the standard WHO insecticide resistance phenotype was examined using Anopheles arabiensis and Anopheles funestus strains: a susceptible strain and the derived resistant strain, selected in the laboratory for resistance to DDT or pyrethroids. The susceptibility of mosquitoes to the pyrethroid deltamethrin or the carbamate bendiocarb was assessed at 18, 25 or 30 °C. The ability of the pyrethroid synergist piperonyl-butoxide (PBO) to restore pyrethroid susceptibility was also assessed at these temperatures. RESULTS: Temperature impacted the toxicity of deltamethrin and bendiocarb. Although the resistant An. funestus strain was uniformly resistant to deltamethrin across temperatures, increasing temperature increased the resistance of the susceptible An. arabiensis strain. Against susceptible An. funestus and resistant An. arabiensis females, deltamethrin exposure at temperatures both lower and higher than standard insectary conditions increased mortality. PBO exposure completely restored deltamethrin susceptibility at all temperatures. Bendiocarb displayed a consistently positive temperature coefficient against both susceptible and resistant An. funestus strains, with survival increasing as temperature increased. CONCLUSIONS: Environmental temperature has a marked effect on the efficacy of insecticides used in public health against important African malaria vectors. Caution must be exercised when drawing conclusions about a chemical's efficacy from laboratory assays performed at only one temperature, as phenotypic resistance can vary significantly even over a temperature range that could be experienced by mosquitoes in the field during a single day. Similarly, it might be inappropriate to assume equal efficacy of a control tool over a geographic area where local conditions vary drastically. Additional studies into the effects of temperature on the efficacy of insecticide-based interventions under field conditions are warranted.

Molecular and physiological analysis of Anopheles funestus swarms in Nchelenge, Zambia.

BACKGROUND: Anopheles funestus has been recognized as a major malaria vector in Africa for over 100 years, but knowledge on many aspects of the biology of this species is still lacking. Anopheles funestus, as with most other anophelines, mate through swarming. A key event that is crucial for the An. funestus male to mate is genitalia rotation. This involves the 135° to 180° rotation of claspers, which are tipped with claws. This physical change then enables the male to grasp the female during copulation. The aim of this investigation was to molecularly characterize wild An. funestus swarms from Zambia and examine the degree of genitalia rotation within the swarm. METHODS: Anopheles funestus swarms were collected from Nchelenge, northern Zambia, during dusk periods in May 2016. All the adults from the swarm were analysed morphologically and identified to species level using a multiplex PCR assay. Anopheles funestus s.s. specimens were molecularly characterized by restriction fragment length polymorphism type and Clade type assays. The different stages of genitalia rotation were examined in the adult males. RESULTS: A total of six swarms were observed during the study period and between 6 and 26 mosquitoes were caught from each swarm. Species analysis revealed that 90% of the males from the swarms were An. funestus s.s. MW-type, with 84% belonging to clade I compared to 14% clade II and 2% failed to amplify. Very few specimens (3.4%) were identified as Anopheles gambiae s.s. Eighty percent of the males from the swarm had complete genitalia rotation. CONCLUSIONS: This is the first time that An. funestus swarms have been molecularly identified to species level. Anopheles funestus swarms appear to be species-specific with no evidence of clade-type differentiation within these swarms. The An. funestus swarms consist mainly of males with fully rotated genitalia, which strongly suggests that swarming behaviour is triggered primarily when males have matured.

Gastric Cancer as Preventable Disease.

Gastric cancer, 1 of the 5 most common causes of cancer death, is associated with a 5-year overall survival rate less than 30%. A minority of cancers occurs as part of syndromic diseases; more than 90% of adenocarcinomas are considered as the ultimate consequence of a longstanding mucosal inflammation. Helicobacter pylori infection is the leading etiology of non-self-limiting gastritis, which may result in atrophy of the gastric mucosa and impaired acid secretion. Gastric atrophy establishes a field of cancerization prone to further molecular and phenotypic changes, possibly resulting in cancer growth. This well-understood natural history provides the clinicopathologic rationale for primary and secondary cancer prevention strategies. A large body of evidence demonstrates that combined primary (H pylori eradication) and secondary (mainly endoscopy) prevention efforts may prevent or limit the progression of gastric oncogenesis. This approach, which is tailored to different country-specific gastric cancer incidence, socioeconomic, and cultural factors, requires that the complementary competences of gastroenterologists, oncologists, and pathologists be amalgamated into a common strategy of health policy.

The Toronto Consensus for the Treatment of Helicobacter pylori Infection in Adults.

BACKGROUND & AIMS: Helicobacter pylori infection is increasingly difficult to treat. The purpose of these consensus statements is to provide a review of the literature and specific, updated recommendations for eradication therapy in adults. METHODS: A systematic literature search identified studies on H pylori treatment. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. Statements were developed through an online platform, finalized, and voted on by an international working group of specialists chosen by the Canadian Association of Gastroenterology. RESULTS: Because of increasing failure of therapy, the consensus group strongly recommends that all H pylori eradication regimens now be given for 14 days. Recommended first-line strategies include concomitant nonbismuth quadruple therapy (proton pump inhibitor [PPI] + amoxicillin + metronidazole + clarithromycin [PAMC]) and traditional bismuth quadruple therapy (PPI + bismuth + metronidazole + tetracycline [PBMT]). PPI triple therapy (PPI + clarithromycin + either amoxicillin or metronidazole) is restricted to areas with known low clarithromycin resistance or high eradication success with these regimens. Recommended rescue therapies include PBMT and levofloxacin-containing therapy (PPI + amoxicillin + levofloxacin). Rifabutin regimens should be restricted to patients who have failed to respond to at least 3 prior options. CONCLUSIONS: Optimal treatment of H pylori infection requires careful attention to local antibiotic resistance and eradication patterns. The quadruple therapies PAMC or PBMT should play a more prominent role in eradication of H pylori infection, and all treatments should be given for 14 days.

Malaria vectors in the Democratic Republic of the Congo: the mechanisms that confer insecticide resistance in Anopheles gambiae and Anopheles funestus.

BACKGROUND: The Democratic Republic of the Congo (DRC) is characterized as a holoendemic malaria area with the main vectors being Anopheles funestus and members of the Anopheles gambiae complex. Due to political instability and socio-economic challenges in the region, knowledge of insecticide resistance status and resistance mechanisms in these vectors is limited. Mosquitoes were collected from a mining site in the north-eastern part of the country and, following identification, were subjected to extensive testing for the target-site and biochemical basis of resistance. Quantitative real-time PCR was used to assess a suite of 10 genes frequently involved in pyrethroid and dichlorodiphenyltrichloroethane (DDT) resistance in An. gambiae females and males. In An. funestus, gene expression microarray analysis was carried out on female mosquitoes. RESULTS: In both species, deltamethrin resistance was recorded along with high resistance and suspected resistance to DDT in An. gambiae and An. funestus, respectively. A total of 85% of An. gambiae carried the kdr mutations as either homozygous resistant (RR) (L1014S, L1014F or both) or heterozygous (RS), however only 3% carried the rdl mutant allele (RS) and no ace-1 mutations were recorded. Synergist assays indicated a strong role for P450s in deltamethrin resistance in both species. In An. gambiae, analysis of transcription levels showed that the glutathione-S-transferase, GSTS1-2, produced the highest fold change in expression (7.6-fold in females and 31-fold in males) followed by GSTE2, thioredoxin peroxidase (TPX2), and cytochrome oxidases (CYP6M2 and CYP6P1). All other genes tested produced fold change values below 2. Microarray analysis revealed significant over-transcription of cuticular proteins as well as CYP6M7, CYP6P9a and CYP6P9b in insecticide resistant An. funestus. CONCLUSIONS: These data show that high levels of deltamethrin resistance in the main malaria vector species, conferred by enzymatic detoxification, are present in the DRC.

Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis--an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks.

BACKGROUND: There are several guidelines addressing the issues around the use of NSAIDs. However, none has specifically addressed the upper versus lower gastrointestinal (GI) risk of COX-2 selective and non-selective compounds nor the interaction at both the GI and cardiovascular (CV) level of either class of drugs with low-dose aspirin. This Consensus paper aims to develop statements and guidance devoted to these specific issues through a review of current evidence by a multidisciplinary group of experts. METHODS: A modified Delphi consensus process was adopted to determine the level of agreement with each statement and to determine the level of agreement with the strength of evidence to be assigned to the statement. RESULTS: For patients with both low GI and CV risks, any non-selective NSAID (ns-NSAID) alone may be acceptable. For those with low GI and high CV risk, naproxen may be preferred because of its potential lower CV risk compared with other ns-NSAIDs or COX-2 selective inhibitors, but celecoxib at the lowest approved dose (200 mg once daily) may be acceptable. In patients with high GI risk, if CV risk is low, a COX-2 selective inhibitor alone or ns-NSAID with a proton pump inhibitor appears to offer similar protection from upper GI events. However, only celecoxib will reduce mucosal harm throughout the entire GI tract. When both GI and CV risks are high, the optimal strategy is to avoid NSAID therapy, if at all possible. CONCLUSIONS: Time is now ripe for offering patients with osteoarthritis the safest and most cost-effective therapeutic option, thus preventing serious adverse events which could have important quality of life and resource use implications. Please see related article: http://dx.doi.org/10.1186/s12916-015-0291-x.

Field study site selection, species abundance and monthly distribution of anopheline mosquitoes in the northern Kruger National Park, South Africa.

BACKGROUND: Knowledge of the ecology and behaviour of a target species is a prerequisite for the successful development of any vector control strategy. Before the implementation of any strategy it is essential to have comprehensive information on the bionomics of species in the targeted area. The aims of this study were to conduct regular entomological surveillance and to determine the relative abundance of anopheline species in the northern Kruger National Park. In addition to this, the impact of weather conditions on an Anopheles arabiensis population were evaluated and a range of mosquito collection methods were assessed. METHODS: A survey of Anopheles species was made between July 2010 and December 2012. Mosquitoes were collected from five sites in the northern Kruger National Park, using carbon dioxide-baited traps, human landing and larval collections. Specimens were identified morphologically and polymerase chain reaction assays were subsequently used where appropriate. RESULTS: A total of 3,311 specimens belonging to nine different taxa was collected. Species collected were: Anopheles arabiensis (n = 1,352), Anopheles quadriannulatus (n = 870), Anopheles coustani (n = 395), Anopheles merus (n = 349), Anopheles pretoriensis (n = 35), Anopheles maculipalpis (n = 28), Anopheles rivulorum (n = 19), Anopheles squamosus (n = 3) and Anopheles rufipes (n = 2). Members of the Anopheles gambiae species complex were the most abundant and widely distributed, occurring across all collection sites. The highest number of mosquitoes was collected using CO2 baited net traps (58.2%) followed by human landing catches (24.8%). Larval collections (17%) provided an additional method to increase sample size. Mosquito sampling productivity was influenced by prevailing weather conditions and overall population densities fluctuated with seasons. CONCLUSION: Several anopheline species occur in the northern Kruger National Park and their densities fluctuate between seasons. Species abundance and relative proportions within the An. gambiae complex varied between collection methods. There is a perennial presence of an isolated population of An. arabiensis at the Malahlapanga site which declined in density during the dry winter months, making this site suitable for a small pilot study site for Sterile Insect Technique as a malaria vector control strategy.

Response to: Bouwman, H. et al. Hallogenated pollutants in terrestrial and aquatic bird eggs: converging patterns of pollutant profiles, and impacts and risks from higher levels Environ. Res. (2013) http://dx.doi.org/10.1016/j.envres.2013.06.003.

Bouwman and coauthors present data and analyses of DDT and other halogenated pollutants in environmental samples and based on their data and analyses thereof, argue against the use of DDT for malaria control. Regrettably, the analyses, presentations, and interpretations of data presented by Bouwman and coauthors are biased and erroneous.

Fecal microbiota transplantation for Clostridium difficile infection: systematic review and meta-analysis.

OBJECTIVES: The clinical and economic burden of Clostridium difficile infection (CDI) is significant. Recurrent CDI management has emerged as a major challenge with suboptimal response to standard therapy. Fecal microbiota transplantation (FMT) has been used as a treatment to reconstitute the normal microbial homeostasis and break the cycle of antibiotic agents that may further disrupt the microbiome. Given the lack of randomized-controlled trials (RCTs) and limitations in previous systematic reviews, we aimed to conduct a systematic review with robust methods to determine the efficacy and safety profile of FMT in CDI. METHODS: An electronic search was conducted using MEDLINE (1946-March 2012), EMBASE (1974-March 2012) and Cochrane Central Register of Controlled Trials (2012). The search strategy was not limited by language. Abstract data were excluded and only completed studies that underwent the full, rigorous peer-review process were included. Studies that used FMT via any delivery modality for laboratory or endoscopically proven CDI with clinical resolution as primary outcome were included. A sample size of 10 or more patients was a further criterion. Elements of the Centre for Reviews and Dissemination checklist and the National Institute of Clinical Excellence quality assessment for case series checklist were employed to determine study quality. Eligibility assessment and data extraction were performed by two independent researchers. Both unweighted pooled resolution rates (UPR) and weighted pooled resolution rates (WPR) were calculated with corresponding 95% confidence intervals (CI) for overall studies, as well as predefined subgroups. RESULTS: Eleven studies with a total of 273 CDI patients treated with FMT were identified; no RCTs were found as none have been published. Two-hundred and forty-five out of 273 patients experienced clinical resolution (UPR 89.7%; WPR 89.1% (95% CI 84 to 93%)). There was no statistically significant heterogeneity between studies (Cochran Q test P=0.13, I(2)=33.7%). A priori subgroup analysis suggested that lower gastrointestinal FMT delivery (UPR 91.4%; WPR 91.2% (95% CI 86 to 95%)) led to a trend towards higher clinical resolution rates than the upper gastrointestinal route (UPR 82.3%; WPR 80.6% (95% CI 69-90%)) (proportion difference of WPR was 10.6% (95% CI -0.6 to 22%)). No difference in clinical outcomes was detected between anonymous vs. patient selected donors. There were no reported adverse events associated with FMT and follow-up was variable from weeks to years. CONCLUSIONS: FMT holds considerable promise as a therapy for recurrent CDI but well-designed, RCTs and long-term follow-up registries are still required. These are needed to identify the right patient, efficacy and safety profile of FMT before this approach can be widely advocated.

Anopheles coluzzii and Anopheles amharicus, new members of the Anopheles gambiae complex.

Two new species within the Anopheles gambiae complex are here described and named. Based on molecular and bionomical evidence, the An. gambiae molecular "M form" is named Anopheles coluzzii Coetzee & Wilkerson sp. n., while the "S form" retains the nominotypical name Anopheles gambiae Giles. Anopheles quadriannulatus is retained for the southern African populations of this species, while the Ethiopian species is named Anopheles amharicus Hunt, Wilkerson & Coetzee sp. n., based on chromosomal, cross-mating and molecular evidence.

A global perspective on irritable bowel syndrome: a consensus statement of the World Gastroenterology Organisation Summit Task Force on irritable bowel syndrome.

Irritable bowel syndrome (IBS) is common in western Europe and North America, and many aspects of its epidemiology, risk factors, and natural history have been described in these regions. Recent data suggest, however, that IBS is also common in the rest of the world and there has been some evidence to suggest some differences in demographics and presenting features between IBS in the west and as it is experienced elsewhere. The World Gastroenterology Organization, therefore, established a Task Force comprising experts on the topic from all parts of the world to examine IBS from a global perspective. IBS does, indeed, seem to be common worldwide though with some significant variations in prevalence rates between regions and countries and there may well be some potentially interesting variations in presenting symptoms and sex distribution. The global map of IBS is far from complete; community-based prevalence data is not available from many areas. Furthermore, while some general trends are evident in terms of IBS impact and demographics, international comparisons are hampered by differences in diagnostic criteria, study location and methodology; several important unanswered questions have been identified that should form the basis for future collaborative research and have the potential to shed light on this challenging disorder.

Fungal infection counters insecticide resistance in African malaria mosquitoes.

The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to infection with the fungus Beauveria bassiana. Four different mosquito strains with high resistance levels against pyrethroids, organochlorines, or carbamates were equally susceptible to B. bassiana infection as their baseline counterparts, showing significantly reduced mosquito survival. Moreover, fungal infection reduced the expression of resistance to the key public health insecticides permethrin and dichlorodiphenyltrichloroethane. Mosquitoes preinfected with B. bassiana or Metarhizium anisopliae showed a significant increase in mortality after insecticide exposure compared with uninfected control mosquitoes. Our results show a high potential utility of fungal biopesticides for complementing existing vector control measures and provide products for use in resistance management strategies.