BackgroundIndia aims to eliminate malaria by 2030; however, a thorough understanding of the current biology and behavior of vector species will facilitate the efforts. Vector species often alter their biting and resting behaviors in response to long-term chemical control measures, posing significant challenges to ongoing vector control interventions. Therefore, it is essential to investigate and update our knowledge of the bionomics of malaria vectors in the current context.MethodsThis study was carried out across 14 districts in eight Indian states between 2021 and 2023, employing various entomological techniques. Anopheles mosquito species were tested for human blood meal preference and Plasmodium infection using polymerase chain reaction (PCR). Insecticide susceptibility status was assessed according to World Health Organization (WHO) protocols, and key metrics, such as degree of exophily, trap density, human biting rate (HBR), and man-hour density (MHD), were determined to understand mosquito abundance and behavior.ResultsAnopheles culicifacies, a major malaria vector species, was found in all study states. The highest indoor MHD of this species was 11.95, recorded in the Kanker district of Chhattisgarh, whereas 27.16 was the highest outdoor MHD as observed in the Bareilly district of Uttar Pradesh. In Assam and Tripura, Anopheles minimus exhibited differential resting behavior, whereas An. baimaii was found to be exophilic in Kokrajhar, Udalguri, and South Tripura. An. stephensi showed endophilic behavior with an indoor MHD of 4.36 in Barmer. An. minimus exhibited high anthropophagic behavior, with a human blood index of 0.94 in South Tripura. A high sporozoite infection rate was observed in An. baimaii (5.88) compared with the other vector species. An. culicifacies was found to be resistant to alpha-cypermethrin (0.05%) in the Jagdalpur and Kanker districts, with possible resistance in Barmer study sites, and resistant to deltamethrin (0.05%) in Kanker, Surendranagar, and Dahod. An. stephensi showed resistance to multiple insecticides in the North Goa.ConclusionsAn. culicifacies was prevalent in all eight study states, with a higher abundance in Kanker and Bareilly. Changes in the resting behavior of An. minimus in Tripura, and insecticide resistance that has developed in An. culicifacies and An. stephensi against pyrethroids poses a significant concern. The findings of this study will aid in implementing effective vector control strategies in India's pre-elimination efforts against malaria.

Malaria elimination remains a global public health priority, particularly in low- and middle-income countries. India has set a target of eliminating malaria by 2030, making it essential to understand gaps in healthcare access, utilization, and preventive practices in endemic areas to guide focused interventions to achieve national and global malaria elimination targets. A subnational, cross-sectional study surveying 37,849 households in ten malaria-endemic states in India, which covered 177,644 individuals, was carried out to estimate the health service and long-lasting insecticidal net (LLIN) utilization for febrile illness and malaria. The study found that the accessibility of a government healthcare facility was within 2.5 km (interquartile range [IQR] 1–5 km), with 57.4

Aquatic temperature influences the development and survival of immature Anopheles stephensi with implications for vector population trends and control strategies under climate change. Temperature was recorded from breeding habitats in Besant Nagar, Chennai, using floatable data loggers, in cemented overhead tank (cOHT), synthetic overhead tank (sOHT), shaded-well (S-Well) and non-shaded well (NS-Well). Hourly temperatures were analyzed across months and seasons. Immature survivorship experiments were carried out in biological incubators simulating habitat temperatures and compared with standard conditions. Adult mosquito longevity was assessed under simulated thatched-roof temperatures. sOHT recorded the highest temperatures, followed by cOHT, with wells recording minimum temperatures. Kruskal-Wallis tests showed significant differences in Hatching rate (HR) and Pupation rate (PR) across habitat temperatures, but not in Emergence rate (ER). Dunn’s analysis revealed better immature development under Standard and Well conditions versus cOHT and sOHT. PERMANOVA confirmed temperature’s strong influence on development, with cOHT causing the greatest survivorship variation. Adults emerging under cOHT conditions showed higher longevity than sOHT, while the adults which emerged from wells survived longest. This study demonstrates habitat-specific thermal effects on An. stephensi development and survival. Vector control through habitat modification, preventing breeding in overhead tanks, and public awareness are crucial for urban malaria elimination.

Abstract Background The growing insecticidal resistance in vector mosquitoes is alarming and calls for an alternative, safe, and eco-friendly control strategy. As an alternative, entomopathogenic fungi (EPF) have gained attention. Hence, the present study evaluated different solid substrates to understand the nutrient requirements of EPF for conidial production and their infectivity against the vector mosquito. Methods Eleven solid substrates were tested for the conidial production of PDBC-Bb5a. The conidial load per gram of substrate was calculated using the spread plate technique. The conidial germination rate at 8, 16, and 24 h after incubation was recorded. The conidial infectivity against Anopheles stephensi was assessed with the WHO cone bioassay tests, exposing mosquitoes to PDBC-Bb5a (1 × 107 conidia/mL) treated cement and mud panels for 30 min. Four replicates, each containing 20 mosquitoes, were maintained for each substrate and the control group. Mosquito mortality was recorded over 10 days. ANOVA was performed to examine the difference between conidia produced on different solid substrates, and the Wilcoxon signed-rank test was used to compare germination rates at 8 versus 16 h of incubation. The Kaplan–Meier test was undertaken to represent the survival function. Results The highest number of PDBC-Bb5a conidia was produced on white rice (6.8 × 105 CFU g−1), followed by sorghum and broken wheat (p < 0.05). Further, the highest germination rate was achieved from conidia produced on white rice (37%) and broken wheat (56%) at 8 and 16 h of incubation, respectively. An increase in germination rate overtime was observed on white rice (37.0 to 54.3% at 8 and 16 h) and broken wheat (36.3% at 8 h and 56.0% at 16 h), yet there was no significant difference among the substrates. The conidia produced on white rice recorded 90% and 86.25% of mortality with 5 (χ2 = 200.32; df = 5; p < 0.01) and 7 (χ2 = 200.32; df = 5; p < 0.01) median survival times of An. stephensi on cement and mud panels, respectively. However, barley observed 51.25 and 47.50% mortality with 10 days of median survival time on cement and mud panels, respectively. Conclusion The study proved that white rice was a better substrate for the production of B. bassiana. Further multicentric studies are needed to test in different eco-geographical areas to assess the efficacy and persistence in varied environmental conditions before considering it in vector control programs.

Management of malaria-negative febrile patients is hampered by a lack of rapid diagnostic tests (RDTs) that guide treatment decisions, increasing the risks of antibiotic overuse and antimicrobial resistance. The simultaneous detection of malaria and C-reactive protein (CRP), a potentially useful host biomarker for distinguishing between bacterial and nonbacterial infections, using RDTs could help address this challenge. A prospective study was conducted at seven sites in India from April to December 2019 to evaluate the performance of the SD BIOSENSOR STANDARD™ Q Malaria/CRP Duo Test (SD BIOSENSOR, Gyeonggi-do, South Korea) against expert microscopy for malaria and against a commercial biochemistry kit for CRP, with a total of 1,799 patients with suspected malaria included in the analysis. The prevalence of malaria parasitemia according to microscopy was 13.3% (3.3% Plasmodium falciparum [P. falciparum], 10.1% Plasmodium vivax [P. vivax]). The Duo test was used to diagnose malaria, P. falciparum, and P. vivax infections, with sensitivities of 97.9% (95% CI: 95.2%-99.1%), 91.4% (95% CI: 81.4%-96.3%), and 95.0% (95% CI: 90.7%-97.3%), respectively. The Duo test performed better for detecting pan malaria and P. vivax infections compared with the routine RDT (SD BIOLINE Malaria P.f/pan antigen test; sensitivity 86.1% [95% CI: 81.1%-89.9%] and 79.9% [95% CI: 73.4%-85.1%] for malaria and P. vivax, respectively). The Duo test's sensitivity and specificity for detecting CRP at levels of 20 mg/L or higher were estimated at 87.4% (95% CI: 84.7%-89.7%) and 94.0% (95% CI: 92.4%-95.3%), respectively. The satisfactory agreement between test results and standard reference methods suggests that the test can be used in malaria-endemic settings; however, additional studies are needed to assess its impact on malaria testing and antibiotic prescription practices.

Mosquitoes are primary vectors for various diseases, with urban areas particularly vulnerable due to dense populations and favourable breeding conditions. In India, mosquito-borne diseases such as malaria, dengue, and lymphatic filariasis remain pressing public health concerns. This study assessed the effectiveness and longevity of Spinosad, a naturally derived bio-larvicide, as an eco-friendly alternative to conventional insecticides. A large-scale field study, following WHO protocols, tested three Spinosad formulations – DT (7.48

India plans to eliminate malaria by 2030, targeting zero local cases by 2027. However, malaria remains prevalent in endemic regions. As a means of addressing this issue, insecticide-treated nets (ITNs) are crucial for prevention. In areas with pyrethroid-resistant vectors, studies indicate that ITNs containing pyrethroids and piperonyl butoxide (PBO) are more effective. However, their physical and chemical durability and bioefficacy in this setting require further evaluation. This study assessed the durability of two pyrethroid–PBO-treated nets and one pyrethroid-only-treated net to determine whether they met the World Health Organization (WHO)’s 3-year operational performance criteria for “long-lasting” classification. A total of 7570 ITNs—2664 Veeralin® (alpha-cypermethrin and PBO), 2246 Olyset® Plus (permethrin and PBO), and 2660 MAGNet® (alpha-cypermethrin)—were distributed among 4186 households, following village randomization in Kurnool district, Andhra Pradesh, India. Following the baseline survey, all distributed ITNs were followed up annually for 36 months to measure ITN survival and bioefficacy. The median functional survival period of the ITNs was estimated at 8 years (interquartile range [IQR] 7.00–9.00 years) for Veeralin®, 5.67 (IQR 5.00–6.33) years for MAGNet®, and 2.51 (IQR 2.19–2.88) years for Olyset® Plus. Bioassays conducted 36 months post-distribution using susceptible mosquito strains revealed 24-h mortality rates of 93.5

BACKGROUND:Plasmodium vivax poses a persistent obstacle to global malaria elimination efforts. While no detectable chloroquine (CQ) resistance has been found in patient samples from India, this observation awaits confirmation. The mechanism of action of CQ continues to be debated. Hemoglobin degradation within the parasite's food vacuole (FV) is integral to its survival and serves as a promising target for antimalarial drug development. METHODS:This study investigates the molecular and structural characteristics of three key FV enzymes-plasmepsin IV (PM_IV), heme detoxification protein (HDP), and falcilysin (FLN)-in P. vivax isolates from India. Genomic DNA from 30 clinical isolates and three chloroquine (CQ)-resistant reference strains was analyzed to identify mutations and assess structural implications through homology modelling. RESULTS:Several nonsynonymous mutations were detected, including c.493G>A (Val165Ile) in PM_IV, c.1537A>G (Asn513Asp), and c.2027G>A (Gly676Asp) in FLN, and a novel in-frame duplication c.28_33dup (ATCGCC) in HDP. Structural modelling revealed that these mutations did not affect the active binding sites of the enzymes. CONCLUSIONS:The genes were highly conserved across isolates, underscoring their important (essential) roles in parasite survival and their potential as drug targets. These are the first findings from the Indian subcontinent that provide critical insights into the mechanisms of chloroquine (CQ) action and resistance, paving the way for novel therapeutic strategies against Plasmodium vivax malaria.

This study aimed to evaluate the susceptibility of immature Anopheles stephensi to temephos formulation, a primary antilarval intervention currently in operational use. The assessment was conducted against both the WHO-recommended discriminatory dosage with temephos (0.25 parts per million [ppm]) and the operational field dosage with temephos 50% emulsifiable concentrate (EC; 1 ppm). F1 generation immature An. stephensi from two areas of Chennai, India was used for the study. The larvae (F1) from both areas were fully susceptible to the WHO discriminatory dosage. Larval susceptibility tests with temephos 50% EC observed 100% mortality in Thiruvanmiyur strains at 40 ppm (lethal concentration at which 99% of the exposed larvae were dead [LC99]: 37.47-45.06 ppm). However, Adyar strains exhibited 98.7% mortality at 50 ppm (LC99: 59.79 ppm). Anopheles stephensi larvae from both areas showed resistance to operational field dosage (1 ppm). Prolonged insecticide exposure precipitates resistance, highlighting the need for routine larvicide efficacy monitoring to support disease elimination efforts.

Mosquitoes are important vectors of several diseases that significantly impact public health globally. This multi-district mosquito survey revealed the diversity and distribution of mosquito species across varied agroecological areas in Kerala, India. Immature and adult mosquito collections were carried out using standard, appropriate sampling methods and the mosquitoes were identified using morphological characters. A total of 108 species belonging to 28 genera were identified from 12,535 specimens. Stegomyia albopicta was the predominant species (54.82%), followed by Culex quinquefasciatus (6.92%). Fourteen known disease vectors were taxonomically identified. Artificial (anthropogenic) habitats such as discarded plastic containers, tyres and latex collection cups contributed to the vector diversity compared to natural ones. Species richness and mosquito species diversity varied across districts, with Wayanad showing the highest diversity. Rarefaction analysis and species-area relationships revealed complex patterns of mosquito biodiversity in agroecological areas. Several rare species were recorded, including a newly described species, Heizmannia rajagopalani. This comprehensive surveillance provides valuable insights into the ecology of mosquitoes in various diverse ecological settings of Kerala, with significant implications for biodiversity conservation and efforts to control vectors.

Urbanization and microclimate variation in cities can influence mosquito behavior and parasite development, thus affecting malaria transmission. This study investigates how the impact of microclimate variations due to household roof types can aid in the survival of Anopheles stephensi and the development of Plasmodium vivax in an urban slum setting. Understanding these vital environmental interactions is essential for devising effective control strategies to achieve malaria elimination. Anopheles stephensi (F1) mosquitoes were membrane-fed with blood collected from P. vivax-infected patients before (day 0) and during (day 1) antimalarial treatment. The parasite development and mosquito survival were monitored in simulated microclimatic conditions of a variety of household roof types (thatched, asbestos, tiled) against standard laboratory conditions. Mosquito dissections were undertaken to detect oocysts and sporozoites in An. stephensi mosquitoes (oocyst: day 3-5, sporozoites: day 7-11). The maximum number of oocysts were detected in infected mosquitoes in thatched-roof conditions, whereas the largest oocyst was in the asbestos roof type. Circumsporozoite-ELISA results indicated the presence of sporozoites in infected mosquitoes for up to 29 days under standard conditions, 18 days in thatched-roof and asbestos roof conditions, and 14 days in tiled conditions. The univariate binary logistic regression model indicated a significant influence of microclimatic conditions of thatched roofs on parasite development. The Kaplan-Meier survival analysis revealed that the median survival of P. vivax-infected An. stephensi in thatched-roof conditions was 14 days, followed by asbestos (11 days) and tiled (10 days) roof conditions. In conclusion, thatched-roof houses were favorable for the development and survival of P. vivax-infected An. stephensi.

BACKGROUND OBJECTIVES:Anopheles stephensi is responsible for the transmission of malaria in urban areas. Vector competence of An. stephensi from a non-malarious (Coimbatore) and highly malarious (Chennai) urban area were investigated to find out the reason for the non-transmission of malaria in Coimbatore. METHODS:Vector competence (Susceptibility/refractoriness) of An. stephensi mosquitoes from Chennai (Malarious) and Coimbatore (Non-malarious), Tamil Nadu, India to Plasmodium vivax (Chennai) were investigated. Bioassays were carried out concurrently in both these strains by artificial membrane feeding technique using the same malaria infected blood. An. stephensi were dissected to observe infection in the midgut and salivary glands. The parasite infection, oocyst and sporozoite positivity rate, the oocyst load, correlation between male-female gametocyte ratio and infection, and Survival Analysis of parasitic stages during sporogony were analyzed and compared. RESULTS:The overall infection rate was 45.8 and 41.2 per cent in Chennai and Coimbatore. Oocyst count ranged from 1-80 and 1-208 respectively and not statistically significant. Oocyst positivity was high from Day 8-21in both strains. The Mean Survival Day (MSD) for oocyst was Day 14 in both strains. Sporozoite was observed in four experiments in each of the strains and the MSD for sporozoites was Day 20 and Day 17 in Chennai and Coimbatore. INTERPRETATION CONCLUSION:An. stephensi of Chennai and Coimbatore are equally susceptible to P. vivax infection and the non-transmission of malaria in Coimbatore can be attributed to external factors such as the presence of preferential breeding habitat, vector density, vector survival, and weather. The only difference observed was the comparatively shortened oocyst maturation time in the Coimbatore strain which requires further investigation.

Abstract Background The global temperature has significantly risen in the past century. Studies have indicated that higher temperature intensifies malaria transmission in tropical and temperate countries. Temperature fluctuations will have a potential impact on parasite development in the vector Anopheles mosquito. Methods Year-long microclimate temperatures were recorded from a malaria-endemic area, Chennai, India, from September 2021 to August 2022. HOBO data loggers were placed in different vector resting sites including indoor and outdoor roof types. Downloaded temperatures were categorised by season, and the mean temperature was compared with data from the same study area recorded from November 2012 to October 2013. The extrinsic incubation period for Plasmodium falciparum and P. vivax was calculated from longitudinal temperatures recorded during both periods. Vector surveillance was also carried out in the area during the summer season. Results In general, temperature and daily temperature range (DTR) have increased significantly compared to the 2012–2013 data, especially the DTR of indoor asbestos structures, from 4.30 ℃ to 12.62 ℃ in 2021–2022, unlike the marginal increase observed in thatched and concrete structures. Likewise, the average DTR of outdoor asbestos structures increased from 5.02 ℃ (2012–2013) to 8.76 ℃ (2021–2022) although the increase was marginal in thatched structures and, surprisingly, showed no such changes in concrete structures. The key finding of the extrinsic incubation period (EIP) is that a decreasing trend was observed in 2021–2022 compared to 2012–2013, mainly in indoor asbestos structures from 7.01 to 6.35 days, which negatively correlated with the current observation of an increase in temperature. Vector surveillance undertaken in the summer season revealed the presence of Anopheles breeding in various habitats. Anopheles stephensi could be collected using CDC light traps along with other mosquito species. Conclusion The microclimate temperature has increased significantly over the years, and mosquitoes are gradually adapting to this rising temperature. Temperature negatively correlates with the extrinsic incubation period of the parasite. As the temperature increases, the development of the parasite in An. stephensi will be faster because of a decrease in EIP, thus requiring relatively fewer days, posing a risk for disease transmission and a hindrance to malaria elimination efforts. Graphical Abstract

Introduction India’s contribution to the malaria burden was highest in South-East Asia Region in 2021, accounting for 79% of the estimated malaria cases and 83% of malaria-related deaths. Intensified Malaria Control Programme supported by Global Funds to Fight against AIDS, Tuberculosis and Malaria has deployed crucial interventions to reduce the overall burden of malaria in India. Evaluation of utilisation of malaria elimination interventions by the community and assessment of the healthcare system is underway in eleven high malaria endemic states in India. Health system preparedness for malaria elimination, logistics, and supply chain management of diagnostic kits and anti-malarial drugs in addition to the knowledge, attitude and practice of the healthcare workers is also being assessed.Methods and analysis The study is being undertaken in 11 malaria endemic states with a variable annual parasite incidence of malaria. In total, 47 districts (administrative unit of malaria control operations) covering 37 976 households are to be interviewed and assessed. We present here the protocol following which the study is being undertaken at the behest and approval of Ministry of Health and Family Welfare in India.Ethics and dissemination No patients were involved in the study. Study findings will be shared with Institutional ethics board of National Institute for Malaria Research New Delhi (NIMR) in a timely, comprehensive, accurate, unbiased, unambiguous and transparent manner and to the National Vector-borne Disease (Malaria) Control Programme officers and the Community public who participated. Important findings will be communicated through community outreach meetings which are existing in the Health system. Results will be informed to study participants via local fieldwork supervised by District Malaria Officers. Also findings will be published in reputed journals based on Indian Council of Medical Research (ICMR) publication policy.The ICMR-NIMR ethics committee approved the study via letter No. NIMR/ECM/2023/Feb/14 dated 24 April 2023 for version 5. All standard ethical practices will be followed.

The threat of zoonotic malaria remains largely overlooked in India, particularly in regions such as the Western Ghats (WG), a biodiversity hotspot. The WG has diverse species of non-human primates that serve as reservoir hosts for simian malaria parasites. The presence of the Leucosphyrus group of mosquitoes and other vectors of human malaria makes WG vulnerable to the risk of parasite spillover. Natural and anthropogenic factors have contributed to rampant changes in the WG landscape, leading to increased interaction with the sylvatic hosts and vectors. The simian host-human-vector-environment interactions govern the transmission dynamics of zoonotic malaria; however, our knowledge of these interlinkages, encompassing the effect of anthropogenic disruptions in the WG is limited. The impending threat of zoonotic malaria in India could decelerate progress toward malaria elimination, warranting a comprehensive and systematic investigation of disease dynamics in the WG.

Abstract Background Mass distributions of long-lasting insecticidal nets (LLINs) have contributed to large reductions in the malaria burden. However, this success is in jeopardy due in part to the increasing pyrethroid-resistant mosquito population as well as low LLINs coverage in various areas because the lifespan of LLINs is often shorter than the interval between replenishment campaigns. New insecticide-treated nets (ITNs) containing pyrethroid and piperonyl-butoxide (PBO) have shown a greater reduction in the incidence of malaria than pyrethroid LLINs in areas with pyrethroid-resistant mosquitoes. However, the durability (attrition, bio-efficacy, physical integrity and chemical retainment) of pyrethroid-PBO ITNs under operational settings has not been fully characterized. This study will measure the durability of pyrethroid-PBO ITNs to assess whether they meet the World Health Organization (WHO) three years of operational performance criteria required to be categorized as “long-lasting”. Methods A prospective household randomized controlled trial will be conducted simultaneously in Tanzania, India and Côte d’Ivoire to estimate the field durability of three pyrethroid-PBO ITNs (Veeralin®, Tsara® Boost, and Olyset® Plus) compared to a pyrethroid LLIN: MAGNet®. Durability monitoring will be conducted up to 36 months post-distribution and median survival in months will be calculated. The proportion of ITNs: (1) lost (attrition), (2) physical integrity, (3) resistance to damage score, (4) meeting WHO bio-efficacy (≥ 95% knockdown after 1 h or ≥ 80% mortality after 24 h for WHO cone bioassay, or ≥ 90% blood-feeding inhibition or ≥ 80% mortality after 24 h for WHO Tunnel tests) criteria against laboratory-reared resistant and susceptible mosquitoes, and insecticidal persistence over time will be estimated. The non-inferiority of Veeralin® and Tsara® Boost to the first-in-class, Olyset® Plus will additionally be assessed for mortality, and the equivalence of 20 times washed ITNs compared to field aged ITNs will be assessed for mortality and blood-feeding inhibition endpoints in the Ifakara Ambient Chamber Test, Tanzania. Conclusion This will be the first large-scale prospective household randomized controlled trial of pyrethroid-PBO ITNs in three different countries in East Africa, West Africa and South Asia, simultaneously. The study will generate information on the replenishment intervals for PBO nets.

Anopheles stephensi (Diptera: Culicidae) is the vector of urban malaria in India and has a significant impact in transmitting infection in cities and towns. Further, WHO has also alarmed its invasive nature as a threat to African countries. Entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae have been found to be highly effective in controlling vector mosquito populations and therefore could be used in integrated vector control programs. Before employing the entomopathogenic fungi into the control programs, an effective isolate must be selected. Two separate experiments were conducted to evaluate the efficacy of Beauveria bassiana (Bb5a and Bb-NBAIR) and Metarhizium anisopliae (Ma4 and Ma-NBAIR) isolates against An. stephensi. Cement and mud panels were treated with fungal conidia with the concentration of 1 × 107 conidia/mL and adult An. stephensi mosquitoes were exposed to the treated panels (24 h after conidia were applied) by conducting WHO cone bioassay tests. The survival of the mosquitoes was monitored daily until the 10th day. In the second experiment, second instar larvae of An. stephensi were treated with fungal (Bb5a, Bb-NBAIR, Ma4 and Ma-NBAIR) conidia and blastospores with the spore concentration of 1 × 107 spores/mL. The survival of larvae was monitored until pupation. All the fungal isolates tested caused mortality in the adult mosquitoes, with varying median survival times. The Bb5a isolate reported lesser median survival times on both cement and mud panels (6 days). The treated mosquitoes showed similar survival rates for each fungal isolate irrespective of the panel type. There was no mortality in the treated larvae; however, a delay in larval development to pupae was observed compared with the untreated control larvae. Ma4-treated larvae took 11 days (95% CI = 10.7–11.2) to become pupae when compared with the untreated control larvae (6 days [95% CI = 5.6–6.3]). The findings of this study will be useful to consider EPF as a tool for the management of vector mosquitoes.

India experienced the second wave of SARS-CoV-2 infection from April 3 to June 10, 2021. During the second wave, Delta variant B.1617.2 emerged as the predominant strain, spiking cases from 12.5 million to 29.3 million (cumulative) by the end of the surge in India. Vaccines against COVID-19 are a potent tool to control and end the pandemic in addition to other control measures. India rolled out its vaccination programme on January 16, 2021, initially with two vaccines that were given emergency authorization–Covaxin (BBV152) and Covishield (ChAdOx1 nCoV- 19). Vaccination was initially started for the elderly (60+) and front-line workers and then gradually opened to different age groups. The second wave hit when vaccination was picking up pace in India. There were instances of vaccinated people (fully and partially) getting infected, and reinfections were also reported. We undertook a survey of staff (front line health care workers and supporting) of 15 medical colleges and research institutes across India to assess the vaccination coverage, incidence of breakthrough infections, and reinfections among them from June 2 to July 10, 2021. A total of 1876 staff participated, and 1484 forms were selected for analysis after removing duplicates and erroneous entries (n = 392). We found that among the respondents at the time of response, 17.6% were unvaccinated, 19.8% were partially vaccinated (received the first dose), and 62.5% were fully vaccinated (received both doses). Incidence of breakthrough infections was 8.7% among the 801 individuals (70/801) tested at least 14 days after the 2nd dose of vaccine. Eight participants reported reinfection in the overall infected group and reinfection incidence rate was 5.1%. Out of (N = 349) infected individuals 243 (69.6%) were unvaccinated and 106 (30.3%) were vaccinated. Our findings reveal the protective effect of vaccination and its role as an essential tool in the struggle against this pandemic.

Background:Tracking the emergence and spread of antimalarial drug resistance has become critical to sustaining progress towards the control and eventual elimination of malaria in South Asia, especially India.Methods:An amplicon sequencing protocol was used for high-throughput molecular surveillance of antimalarial drug resistance in a total of 158 isolates at three sites in India: Chennai, Nadiad and Rourkela. Five genes of the Plasmodium falciparum implicated in antimalarial resistance were investigated here; Pfcrt for chloroquine resistance, Pfdhfr for pyrimethamine resistance, Pfdhps for sulfadoxine resistance, Pfk13 for artemisinin resistance and Pfmdr1 for resistance to multiple antimalarials.Results:Mutations in the propeller domain of PfK13 were observed in two samples only, however these mutations are not validated for artemisinin resistance. A high proportion of parasites from the P. falciparum dominant site Rourkela showed wild-type Pfcrt and Pfdhfr haplotypes, while mutant Pfcrt and Pfdhfr haplotypes were fixed at the P. vivax dominant sites Chennai and Nadiad. The wild-type PfDHPS haplotype was predominant across all study sites. Finally, we observed the largest proportion of suspected multi-clonal infections at Rourkela, which has the highest transmission of P. falciparum among our study sites.Conclusion:This is the first simultaneous high-throughput next generation sequencing of five complete P. falciparum genes from infected patients in India.