The national distribution of lymphatic filariasis cases in Malawi using patient mapping and geostatistical modelling.

BACKGROUND: In 2020 the World Health Organization (WHO) declared that Malawi had successfully eliminated lymphatic filariasis (LF) as a public health problem. Understanding clinical case distributions at a national and sub-national level is important, so essential care packages can be provided to individuals living with LF symptoms. This study aimed to develop a national database and map of LF clinical cases across Malawi using geostatistical modelling approaches, programme-identified clinical cases, antigenaemia prevalence and climate information. METHODOLOGY: LF clinical cases identified through programme house-to-house surveys across 90 sub-district administrative boundaries (Traditional Authority (TA)) and antigenaemia prevalence from 57 sampled villages in Malawi were used in a two-step geostatistical modelling process to predict LF clinical cases across all TAs of the country. First, we modelled antigenaemia prevalence in relation to climate covariates to predict nationwide antigenaemia prevalence. Second, we modelled clinical cases for unmapped TAs based on our antigenaemia prevalence spatial estimates. PRINCIPLE FINDINGS: The models estimated 20,938 (95% CrI 18,091 to 24,071) clinical cases in unmapped TAs (70.3%) in addition to the 8,856 (29.7%), programme-identified cases in mapped TAs. In total, the overall national number of LF clinical cases was estimated to be 29,794 (95% CrI 26,957 to 32,927). The antigenaemia prevalence and clinical case mapping and modelling found the highest burden of disease in Chikwawa and Nsanje districts in the Southern Region and Karonga district in the Northern Region of the country. CONCLUSIONS: The models presented in this study have facilitated the development of the first national LF clinical case database and map in Malawi, the first endemic country in sub-Saharan Africa. It highlights the value of using existing LF antigenaemia prevalence and clinical case data together with modelling approaches to produce estimates that may be used for the WHO dossier requirements, to help target limited resources and implement long-term health strategies.

Elimination of lymphatic filariasis as a public health problem in Malawi.

BACKGROUND: Lymphatic filariasis (LF) is a parasitic disease transmitted by mosquitoes, causing severe pain, disfiguring, and disabling clinical conditions such as lymphoedema and hydrocoele. LF is a global public health problem affecting 72 countries, primarily in Africa and Asia. Since 2000, the World Health Organization (WHO) has led the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to support all endemic regions. This paper focuses on the achievements of the Malawi LF Elimination Programme between 2000 and 2020 to eliminate LF as a public health problem, making it the second sub-Saharan country to receive validation from the WHO. METHODOLOGY/PRINCIPAL FINDINGS: The Malawi LF Programme addressed the widespread prevalence of LF infection and disease across the country, using the recommended WHO GPELF strategies and operational research initiatives in collaboration with key national and international partners. First, to stop the spread of infection (i.e., interrupt transmission) and reduce the circulating filarial antigen prevalence from as high as 74.4% to below the critical threshold of 1-2% prevalence, mass drug administration (MDA) using a two-drug regime was implemented at high coverage rates (>65%) of the total population, with supplementary interventions from other programmes (e.g., malaria vector control). The decline in prevalence was monitored and confirmed over time using several impact assessment and post-treatment surveillance tools including the standard sentinel site, spot check, and transmission assessment surveys and alternative integrated, hotspot, and easy-access group surveys. Second, to alleviate suffering of the affected populations (i.e., control morbidity) the morbidity management and disability prevention (MMDP) package of care was implemented. Specifically, clinical case estimates were obtained via house-to-house patient searching activities; health personnel and patients were trained in self-care protocols for lymphoedema and/or referrals to hospitals for hydrocoele surgery; and the readiness and quality of treatment and services were assessed with new survey tools. CONCLUSIONS: Malawi's elimination of LF will ensure that future generations are not infected and suffer from the disfiguring and disabling disease. However, it will be critical that the Malawi LF Elimination programme remains vigilant, focussing on post-elimination surveillance and MMDP implementation and integration into routine health systems to support long-term sustainability and ongoing success. SUMMARY: Lymphatic filariasis, also known as elephantiasis, is a disabling, disfiguring, and painful disease caused by a parasite that infected mosquitoes transmit to millions of people worldwide. Since 2000, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) has supported endemic countries such as Malawi in south-eastern Africa, to eliminate the disease as a public health problem. The Malawi National LF Elimination Programme has worked tirelessly over the past two decades to implement the GPELF recommended strategies to interrupt the transmission with a two-drug regime, and to alleviate suffering in patients with lymphoedema and/or hydrocoele through morbidity management and disability prevention. Additionally, the LF Programme has collaborated with national and international stakeholders to implement a range of supplementary operational research projects to address outstanding knowledge gaps and programmatic barriers. In 2020, the World Health Organisation validated that Malawi had successfully eliminated LF as a public health problem, making it the second country in sub-Saharan Africa to achieve this, which is remarkable given that Malawi previously had very high infection rates. The LF Programme now remains vigilant, putting its efforts towards post-elimination surveillance and the continued implementation of care for patients with chronic conditions. Malawi's elimination of LF will ensure that future generations are not affected by this devastating disease.

Mental health conditions in people affected by filarial lymphoedema in Malawi: prevalence, associated risk factors and the impact of an enhanced self-care intervention.

BACKGROUND: This study aimed to determine the key mental health indicators affecting people affected by lymphatic filariasis (LF) lymphoedema by assessing the prevalence of depressive symptoms and quality of life (QOL), identifying associated sociodemographic and clinical risk factors, and evaluating the impact of an enhanced self-care intervention for lymphoedema management. METHODS: A prospective cohort study of adults with filarial lymphoedema from two regions of Malawi was conducted over six months in 2021. Depressive symptoms and QOL were assessed using Patient Health Questionnaire (PHQ-9) and LF Specific QOL Questionnaire, respectively, at baseline (pre-intervention), 3- and 6-months (postintervention). Beta regression analysis identified risk factors, and assessed the impact of the intervention. RESULTS: Three hundred eleven affected individuals were surveyed with 23% (95% CI 18%-29%) reporting mild/moderate depressive symptoms and 31% (95% CI 26%-37%) reporting moderately low/low QOL. Higher depressive symptom scores were associated with high frequency of acute filarial attack episodes. Individuals with higher depressive symptoms (Adjusted Odds Ratios (AOR) 0.93, 95% CI 0.93-0.93) and lower QOL (AOR 0.98, 0.98-0.98) showed greatest improvement in mental health indicators over 3-months but was not sustained to the same level at 6-months. CONCLUSIONS: Sustained morbidity management and psychological support is recommended for affected persons to ensure long-term positive mental health and clinical outcomes. CONTEXTE: Cette étude vise à déterminer les principaux indicateurs de santé mentale affectant les personnes atteintes de lymphœdème dû à la filariose lymphatique (FL) en évaluant la prévalence des symptômes dépressifs et la qualité de vie (QV), en identifiant les facteurs de risque sociodémographiques et cliniques associés, et en évaluant l'impact d'une intervention améliorée d'autosoins pour la gestion du lymphœdème. MÉTHODES: Une étude de cohorte prospective d'adultes atteints de lymphoedème filaire dans deux régions du Malawi a été menée pendant six mois en 2021. Les symptômes dépressifs et la qualité de vie ont été évalués à l'aide du questionnaire sur la santé des patients (PHQ-9) et du questionnaire sur la qualité de vie spécifique au lymphœdème, respectivement, au début de l'étude (avant l'intervention), et à 3 puis 6 mois après l'intervention. Une analyse de régression beta a permis d'identifier les facteurs de risque et d'évaluer l'impact de l'intervention. RÉSULTATS: Trois cent onze personnes affectées ont été interrogées, dont 23% (95% CI 18%-29%) ont déclaré des symptômes dépressifs légers/modérés et 31% (95% CI 26%-37%) ont déclaré une qualité de vie modérément faible/faible. Des scores élevés de symptômes dépressifs ont été associés à une fréquence élevée d'épisodes de crises filariennes aiguës. Les personnes présentant des symptômes dépressifs plus élevés (rapport de cotes ajusté (RCA) 0.93, IC à 95 % 0.93-0.93) et une qualité de vie plus faible (RCA 0.98, 0.98-0.98) ont montré la plus grande amélioration des indicateurs de santé mentale au cours des trois mois, mais cette amélioration ne s'est pas maintenue au même niveau au cours des six mois suivants. CONCLUSION: Gestion de la morbidité et soutien psychologique sont des éléments clés pour garantir une santé mentale et des résultats cliniques satisfaisants de personnes atteintes sur le long terme. ANTECEDENTES: Este estudio tuvo como objetivo determinar los indicadores clave de salud mental que afectan a las personas afectadas por linfedema por filariasis linfática (FL) mediante la evaluación de la prevalencia de síntomas depresivos y calidad de vida (CdV), la identificación de factores de riesgo sociodemográficos y clínicos asociados, y la evaluación del impacto de una intervención de autocuidado mejorada para el manejo del linfedema. MÉTODOS: Se realizó un estudio prospectivo de cohortes de adultos con linfedema filarial de dos regiones de Malawi durante seis meses en 2021. Los síntomas depresivos y la calidad de vida se evaluaron mediante el Cuestionario de Salud del Paciente (PHQ-9) y el Cuestionario de Calidad de Vida específico para el LF Cuestionario, respectivamente, al inicio (preintervención) y a los 3 y 6 meses (posintervención). El análisis de regresión beta identificó los factores de riesgo y evaluó el impacto de la intervención. RESULTADOS: Se encuestó a 311 afectados, de los cuales el 23% (IC 95%, 18%-29%) presentaba síntomas depresivos leves/moderados y el 31% (IC 95%, 26%-37%) una CdV moderadamente baja/baja CdV. Las puntuaciones más altas de síntomas depresivos se asociaron con una alta frecuencia de episodios de ataques agudos de filarias. Los individuos con mayores síntomas depresivos (Odds Ratios Ajustados [ORA] 0.93; IC 95%: 0.93-0.93) y menor CdV (ORA 0.98; 0.98-0.98) mostraron la mayor mejoría en los indicadores de salud mental a los 3 meses, pero no se mantuvo al mismo nivel a los 6 meses. CONCLUSIONES: Se recomienda el manejo sostenido de la morbilidad y el apoyo psicológico a las personas afectadas para garantizar resultados clínicos y de salud mental positivos a largo plazo.

Anopheles funestus sensu stricto Giles (Diptera:Culicidae) bites after sunrise at two rural villages in northern Malawi and its implications for malaria vector control.

Introduction: Malawi has scaled up distribution and use of LLINs but their effectiveness depends on vector behaviour. This study reports information on where and when peak biting takes place by Anopheles vectors at two study sites in northern Malawi. Methods: The study was carried out at a single village each in Nkhata Bay and Karonga districts, northern Malawi. Monthly, three teams of four people each sampled mosquitoes using Human Landing Collections (HLCs) from 6.00 pm to 6.00 am. Mosquitoes were counted and identified by PCR. Plasmodium falciparum sporozoites were detected by ELISA and an entomological inoculation rate was estimated. Results: A total of 4,668 and 2,079 mosquitoes were sampled in Nkhata Bay and Karonga districts respectively. An. funestus s.s was common (91.3%; n = 2,611) in Nkhata Bay while An. arabiensis was common (96.9%; n = 706) in Karonga. Pf sporozoite rates varied from 0.8% (4/484) to 3.3% (51/1558). Individuals in Nkhata Bay received more bites (approx. 200 bites/ person/ night) compared to Karonga (approx. 50 bites/ person/ night). An. funestus was more likely to bite indoors (p=0.002) while An. arabiensis was (p=0.05) more likely to bite outdoors. Furthermore, An. funestus peak biting was in the early morning hours from 4:00 am (approx. 331 and 177 bites/ person/ night indoors and outdoors respectively) and remained high till 6:00 am. An. arabiensis peak biting (approx. 63 and 62 bites/ person/ night indoors and outdoors respectively) was around mid-night (12:00). An EIR of 108.4 infective bites/ person/ year was estimated for Nkhata Bay compared to 9.1 infective bites/ person/ year for Karonga. Conclusion: An. funestus s.s. had a considerable Pf sporozite infection rate and EIR. The shift in biting behaviour shown by this species poses a challenge to malaria control. Further studies are required to understand the biting behaviour of Anopheles vectors in Malawi.

The development and roll-out of a new hydrocoele surgery facility assessment tool for the elimination of lymphatic filariasis.

A hydrocoele surgery facility assessment tool (HSFAT) was developed to assess the readiness of hydrocoele surgery services in health facilities prior to implementation of hydrocoele surgical campaigns for the elimination of lymphatic filariasis (LF). A first version of the tool was piloted in Bangladesh, Malawi and Nepal in 2019, then, following feedback from country programme managers, a second version of the tool was rolled out across countries implementing hydrocoele surgery in the Accelerating the Control of Neglected Tropical Diseases (Ascend) West and Central Africa Programme, including Benin, Burkina Faso, Ghana, Guinea, Niger and Nigeria. The HSFAT assessed facilities across 10 domains: background information, essential amenities, emergency patient transfer, laboratory capacity, surgical procedures and trained staff, infection prevention, non-disposable basic equipment, disposable basic equipment, essential medicines and current hydrocoele practices. The HSFAT results highlight key areas for improvement in different countries and can be used to develop a quality improvement plan, which may include actions with agreed deadlines to improve the readiness and quality of hydrocoele surgery services provided by the health facility, prior to implementation of surgical campaigns and assist country programmes to achieve the dossier requirements set out by the World Health Organization for the elimination of LF.

Significant improvement in quality of life following surgery for hydrocoele caused by lymphatic filariasis in Malawi: A prospective cohort study.

BACKGROUND: Lymphatic filariasis (LF) is a mosquito-borne parasitic infection that causes significant disabling and disfiguring clinical manifestations. Hydrocoele (scrotal swelling) is the most common clinical condition, which affects an estimated 25 million men globally. The recommended strategy is surgical intervention, yet little is known about the impact of hydrocoele on men's lives, and how it may change if they have access to surgery. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively recruited and followed-up men who underwent surgery for hydrocoele at six hospitals in an LF endemic area of Malawi in December 2015. Men were interviewed at hospitals pre-surgery and followed-up at 3-months and 6-months post-surgery. Data on demographic characteristics, clinical condition, barriers to surgery, post-surgery symptoms/complications and quality of life indicators were collected and analysed pre- and post-surgery, by age group and stage of disease (mild/moderate vs. severe), using chi-square tests and student's t test (paired). 201 men were interviewed pre-surgery, 152 at 3-months and 137 at 6-months post-surgery. Most men had unilateral hydrocoeles (65.2%), mild/moderate stages (57.7%) with an average duration of 11.4 years. The most reported cause of hydrocoele was it being sexually transmitted (22.4%), and the main barrier to surgery was the cost (36.3%). Pre-surgery, a significant difference in the scrotum side affected was found by age group (X2 = 5.978, p = 0.05), and men with severe stage hydrocoele reported more problems with their quality of life than those with mild/moderate stage (t = 2.793; p = 0.0006). Post-surgery, around half of the men reported some pain/discomfort (55.9%), swelling (8.6%), bleeding (3.3%) and infection (5.9%), most of which had resolved at 3-months when the most significant improvements in their quality of life were found (t = 21.3902; p = 0.000). Post-surgery at 6 months all men reported no physical, social, psychological problems and took no time off work. CONCLUSION/SIGNIFICANCE: Surgery had a significant positive impact on many aspects of a patient's life, and the expansion of this treatment to all those affected in LF endemic areas would greatly improve the quality of men's and their families' lives, and greatly contribute to the global goal of providing universal health care.

Economic benefits and costs of surgery for filarial hydrocele in Malawi.

BACKGROUND: Lymphatic filariasis (LF) is endemic in 72 countries of Africa, Asia, Oceania, and the Americas. An estimated 25 million men live with the disabling effects of filarial hydrocele. Hydrocele can be corrected with surgery with few complications. For most men, hydrocelectomy reduces or corrects filarial hydrocele and permits them to resume regular activities of daily living and gainful employment. METHODOLOGY AND PRINCIPAL FINDINGS: This study measures the economic loss due to filarial hydrocele and the benefits of hydrocelectomy and is based on pre- and post-operative surveys of patients in southern Malawi. We find the average number of days of work lost due to filarial hydrocele and daily earnings for men in rural Malawi. We calculate average annual lost earnings and find the present discounted value for all years from the time of surgery to the end of working life. We estimate the total costs of surgery. We compare the benefit of the work capacity restored to the costs of surgery to determine the benefit-cost ratio. For men younger than 65 years old, the average annual earnings loss attributed to hydrocele is US$126. The average discounted present value of lifetime earnings loss for those men is US$1684. The average budgetary cost of the hydrocelectomy is US$68. The ratio of the benefit of surgery to its costs is US$1684/US$68 or 24.8. Sensitivity analysis demonstrates that the results are robust to variations in cost of surgery and length of working life. CONCLUSION: The lifetime benefits of hydrocelectomy-to the man, his family, and his community-far exceed the costs of repairing the hydrocele. Scaling up subsidies to hydrocelectomy campaigns should be a priority for governments and international aid organizations to prevent and alleviate disability and lost earnings that aggravate poverty among the many millions of men with filarial hydrocele.

Increasing insecticide resistance in Anopheles funestus and Anopheles arabiensis in Malawi, 2011-2015.

BACKGROUND: Susceptibility of principal Anopheles malaria vectors to common insecticides was monitored over a 5-year period across Malawi to inform and guide the national malaria control programme. METHODS: Adult blood-fed Anopheles spp. and larvae were collected from multiple sites in sixteen districts across the country between 2011 and 2015. First generation (F1) progeny aged 2-5 days old were tested for susceptibility, using standard WHO procedures, against pyrethroids (permethrin and deltamethrin), carbamates (bendiocarb and propoxur), organophosphates (malathion and pirimiphos-methyl) and an organochlorine (DDT). RESULTS: Mortality of Anopheles funestus to deltamethrin, permethrin, bendiocarb and propoxur declined significantly over the 5-year (2011-2015) monitoring period. There was wide variation in susceptibility to DDT but it was not associated with time. In contrast, An. funestus exhibited 100% mortality to the organophosphates (malathion and pirimiphos-methyl) at all sites tested. There was reduced mortality of Anopheles arabiensis to deltamethrin over time though this was not statistically significant. However, mortality of An. arabiensis exposed to permethrin declined significantly over time. Anopheles arabiensis exposed to DDT were more likely to be killed if there was high ITN coverage in the mosquito collection area the previous year. There were no other associations between mosquito mortality in a bioassay and ITN coverage or IRS implementation. Mortality of An. funestus from four sites exposed to deltamethrin alone ranged from 2 to 31% and from 41 to 94% when pre-exposed to the synergist piperonyl butoxide followed by deltamethrin. For permethrin alone, mortality ranged from 2 to 13% while mortality ranged from 63 to 100% when pre-exposed to PBO. CONCLUSION: Pyrethroid resistance was detected in An. funestus and An. arabiensis populations across Malawi and has worsened over the last 5 years. New insecticides and control strategies are urgently needed to reduce the burden of malaria in Malawi.

A cohort study of the effectiveness of insecticide-treated bed nets to prevent malaria in an area of moderate pyrethroid resistance, Malawi.

BACKGROUND: Insecticide-treated bed nets (ITNs) are the cornerstone of malaria control in sub-Saharan Africa but their effectiveness may be compromised by the spread of pyrethroid resistance among malaria vectors. The objective of this investigation was to assess the effectiveness of ITNs to prevent malaria in an area of Malawi with moderate pyrethroid resistance. METHODS: One deltamethrin ITN was distributed in the study area for every two individuals in each household plus one extra ITN for households with an odd number of residents. A fixed cohort of 1,199 children aged six to 59 months was seen monthly for one year and at sick visits to measure malaria infection and use of ITNs. Insecticide resistance among malaria vectors was measured. The effect of ITN use on malaria incidence was assessed, adjusting for potential confounders using generalized estimating equations accounting for repeated measures. RESULTS: There were 1,909 infections with Plasmodium falciparum over 905 person-years at risk (PYAR), resulting in an observed incidence of 2.1 infections per person-year (iPPY). ITNs were used during 97% of the PYAR. The main vector was Anopheles funestus: mortality in WHO tube assays after exposure to 0.05% deltamethrin was 38% (95% confidence interval (CI) 29-47), and resistance was due to elevated oxidase enzymes. After adjusting for potential confounders, the incidence of malaria infection among ITN users was 1.7 iPPY (95% CI 1.5-2.1) and among non-bed net users was 2.6 iPPY (95% CI 2.0-3.3). Use of ITNs reduced the incidence of malaria infection by 30% (rate ratio 0.7; 95% CI, 0.5-0.8) compared to no bed nets. CONCLUSION: ITNs significantly reduced the incidence of malaria infection in children in an area with moderate levels of pyrethroid resistance and considerable malaria transmission. This is the first study to show that ITNs provide protection in areas where pyrethroid-resistant An. funestus is the major malaria vector. Malaria control programmes should continue to distribute and promote ITNs in areas with low to moderate pyrethroid resistance; however, insecticide resistance may intensify further and it is not known whether ITNs will remain effective at higher levels of resistance. There is an urgent need to identify or develop new insecticides and technologies to limit the vulnerability of ITNs to insecticide resistance.

Characterization of the Anopheles funestus group, including Anopheles funestus-like, from Northern Malawi.

BACKGROUND: Limited information is available on malaria vector composition, feeding habits and malaria transmission in northern Malawi. Evidence of mosquito species diversity in this area was established in 2009, when Anopheles funestus-like, a new member of the An. funestus group was described. Additional biological information is needed to identify this species and to understand its role in malaria transmission. METHODS: Anopheline mosquitoes were collected in northern Malawi and analyzed for Plasmodium species infection, blood meal source and susceptibility to insecticides. A new hydrolysis probe assay was designed to identify An. funestus-like. RESULTS: Anopheles funestus and An. rivulorum predominated in the indoor collections. Most An. funestus-like were collected indoors, mainly fed on animals and were uninfected with P. falciparum. Anopheles funestus showed insecticide resistance to deltamethrin and bendiocarb. A high-precision hydrolysis probe assay was successfully developed to identify An. funestus-like. DISCUSSION: Four species in the An. funestus group were collected in Karonga. Resistance to deltamethrin and bendiocarb was observed in An. funestus and further investigation is needed on the insecticide resistance mechanisms. Anopheles funestus-like, while collected indoors, is mainly zoophilic and most likely not a malaria vector. ACCESSION NUMBERS: An. funestus (GenBank accession no. KC771136), An. funestus-like (GenBank accession no. KC771137), An. parensis GenBank accession no. KC771138) and An. vaneedeni GenBank accession no. KC771139).

Impact of indoor residual spraying with lambda-cyhalothrin on malaria parasitemia and anemia prevalence among children less than five years of age in an area of intense, year-round transmission in Malawi.

Little is known about the impact of indoor residual spraying (IRS) in areas with intense malaria transmission such as sub-Saharan Africa. In Malawi, IRS with lambda-cyhalothrin has been applied annually in an area of intense year-long transmission since 2007. We evaluated the impact of IRS on parasitemia and anemia prevalence in children less than five years of age by using a cross-sectional household survey conducted in 2009, six months after the second IRS spray round. We measured malaria parasitemia and anemia (hemoglobin level < 11 g/dL) in 899 children less than five years of age and used binomial regression to assess the impact of IRS by comparing children living in a household sprayed with IRS (direct IRS) with those in a household not sprayed with IRS, but in an IRS area (indirect IRS) and those living in a household not sprayed with IRS and not in an IRS area (no IRS). In the IRS area, 77% of households reported receiving IRS. Adjusting for bed net use, house construction, and socioeconomic status, we found that receiving direct IRS and indirect IRS were significantly associated with a 33% (95% confidence interval [CI] = 1-54%) and 46% (95% CI = 20-64%) reduction in parasitemia and a 21% (95% CI = 4-34%) and 30% (95% CI = 12-45%) reduction in anemia prevalence, respectively.

A new species concealed by Anopheles funestus Giles, a major malaria vector in Africa.

The major malaria vector Anopheles funestus belongs to a group of morphologically similar species that are commonly distinguished from one another through the use of chromosomal and molecular techniques. Indoor resting collections of mosquitoes from Malawi were initially identified as An. funestus by morphology, but failed to have this confirmed by the species-specific polymerase chain reaction assay. Sequence analysis of the internal transcribed spacer region 2 identified variations within the An. funestus-specific primer binding site and showed a sequence variation of 4.5% compared with An. funestus. Domain 3 analysis showed sequence variation of 1.5% from An. funestus. Cytogenetic analysis of the polytene chromosome banding arrangements showed that the specimens were homosequential with An. funestus, with fixed inverted arrangements of the 3a, 3b, and 5a inversions commonly polymorphic in An. funestus. The chromosomes of hybrid females showed levels of asynapsis typical of inter-species crosses. These molecular and cytogenetic observations support the conclusion that this Malawi population is a new species and it has provisionally been named An. funestus-like.