For diagnosis of malaria, popular brands of rapid test kits collectively termed as &a... more For diagnosis of malaria, popular brands of rapid test kits collectively termed as "dipsticks" were subject to field evaluation in northeastern India for their comparative sensitivity and specificity vis-à-vis conventional microscopic results. Dipsticks based on Plasmodium falciparum-specific histidine-rich protein (Pf HRP-2) antigen capture assay revealed 100% sensitivity and high specificity (94-100%); thus, they were concluded to be reliable tools for confirmed diagnosis of malarial infection. However, an advanced version of the same kit, having incorporated additional pan-malarial monoclonal antibody, was found to be less sensitive (71%) for non-falciparum infections. Besides, Pf HRP-2-based kits continued to show positive results up to day 7, even after clearance of parasitemia on account of persistent antigenemia. This very limitation seemed to have been overcome by parasite-specific lactate dehydrogenase (pLDH) enzyme-based kit. This kit was observed to have high sensitivity (81-89%) and specificity (100%) for both falciparum and non-falciparum malaria, but cannot distinguish mono-infection from mixed infections. It is concluded that the rational use of these kits would accord health benefits in terms of early detection and prompt treatment, reduce drug pressure, and possibly delay the emergence and spread of multi-drug-resistant strains of malarial parasites.
Malaria, particularly due to Plasmodium falciparum, remains a major public health threat in Ethio... more Malaria, particularly due to Plasmodium falciparum, remains a major public health threat in Ethiopia. Artemether-lumefantine (AL) has been the first-line antimalarial drug against uncomplicated P. falciparum malaria in the country since 2004. Regular monitoring of anti-malarial drugs is recommended by the World Health Organization (WHO) to help early detection of drug resistant strains of the parasite and contain their rapid spread. The objective of this study was to assess the therapeutic efficacy of AL in a high-transmission setting in Ethiopia. The study site was Setit Humera, northwest Ethiopia. Single-arm prospective study of a 28-day follow-up was conducted from October 2014 to January 2015 according to the revised WHO 2009 drug efficacy study protocol. Study end-points were classified into primary end-point and secondary end-point. While the primary end-point was the day-28 adequate clinical and parasitological response the secondary end-points were clinical and parasitological evaluations (parasite, fever and gametocyte clearance rate, incidence of drug adverse events) and the relative increment in hemoglobin (Hb) level from baseline to day (D) 14 and D28. A total of 92 patients were enrolled and 79 had completed the 28-day follow-up period. The overall cure rate was 98.8% with 95% confidence interval of 0.915– 0.998 without polymerase chain reaction correction. The parasite clearance rate was high with fast resolution of clinical symptoms; 100% of the study participants cleared parasitae-mia and fever on D3. Gametocyte carriage was reduced from 7% on D0 to 1% on D3 and complete clearance was achieved on D14. Mean Hb concentration significantly increased on D28 compared to that on D14. There was no serious adverse event. AL was efficacious and safe in a high-transmission setting for treatment of uncomplicated falciparum malaria.
(CoH1,N3PS) C, H, S, P, S. L-I1 had bp 114-11.5' (1.6 mm), mp 41-43', 9... more (CoH1,N3PS) C, H, S, P, S. L-I1 had bp 114-11.5' (1.6 mm), mp 41-43', 97 (e 1.7, ... C&). 2,4,6-Tris(~-2-methyI-l-aziridinyl)-s-triazine (o-III).--Csing the method described by S~haefer,~~ 3.1 g (0.055 mole) of D-propyleiiimine was converted to 1.6 g (36%) of 0-11, ...
Indoor, day-resting collections of Anopheles minimus mosquitos from human dwellings in the study ... more Indoor, day-resting collections of Anopheles minimus mosquitos from human dwellings in the study area in Assam, India, indicated that these insects were prevalent throughout the year and that their maximum abundance occurred from March to August. A. minimus was identified as a vector of malaria, and sporozoite infections were recorded every month of the year, with the highest rating occurring in October. The mosquito was highly anthropophilic and fed on human hosts (indoor) all through the night, but feeding was more pronounced between 01:00 and 04:00, the person-biting rate was 13.7 per night. Breeding occurred throughout the year in slow-flowing streams with grassy banks. A. fluviatilis was also identified as a vector of malaria in the study area but occurred in low density, and sporozoite infections were only seasonal.
Anopheles (Cellia) annularis Van der Wulp is a complex of two sibling species provisionally desig... more Anopheles (Cellia) annularis Van der Wulp is a complex of two sibling species provisionally designated as species A and B and can only be differentiated on the basis of the paracentric inversion in the ovarian polytene chromosomes. To analyze the distribution of these two species and to develop a molecular method for the identification of these two cryptic species, we sequenced the ribosomal DNA internal transcribed spacer 2 (ITS2) and domain 3 (D3) of A. annularis specimens collected from Sonapur (Assam), Jabalpur (Madhya Pradesh), Ranchi (Jharkhand), and Ghaziabad (Uttar Pradesh). We did not find any sequence variation among the specimens collected from Assam, Madhya Pradesh, and Jharkhand states, whereas two types of sequences were obtained from the specimens collected from the state of Uttar Pradesh, which correspond to species A and B of the A. annularis complex. Species A was more prevalent among the all four regions studied. The ITS2 sequence of species A showed unique restriction sites for MvaI and Eco24I, while species B displayed HinfI and NruI sites. Similarly, the D3 sequence of species A showed unique restriction site for Alw26I, while species B showed a unique KpnI site. In this study, we report for the first time the development of ribosomal DNA polymerase chain reaction-restriction fragment length polymorphism methods for identifying these two cryptic species of the Annularis complex.
... The situation is further complicated by high proportion of P. falciparum >60%), a killer p... more ... The situation is further complicated by high proportion of P. falciparum >60%), a killer parasite that has become multi-drug resistant (Dua et. al. 2003; Dev et al, 2003). ... Med. Intenl. Hlth.. Vol.1.pp816-819. Dua VK, Dev V, Phookan S, Gupta NC,. Sharma VP, Subbarao SK. 2003. ...
... It is vital to seek greater political commitment for strengthening healthcare services in the... more ... It is vital to seek greater political commitment for strengthening healthcare services in the communities most at risk, and maintaining constant vigil by intensive surveillance and monitoring to avert the impending disease outbreaks for meeting the ... (8.) Jana-Kara BR, Jihullah WA ...
Long-lasting insecticidal nets (LLINs) are being promoted for malaria vector control in the north... more Long-lasting insecticidal nets (LLINs) are being promoted for malaria vector control in the northeastern Indian state of Assam. A cross-sectional study was conducted to assess the current residual bio-efficacy and durability of both the Olyset(®) and PermaNet(®)2.0 LLINs that were distributed earlier in 2009, 2011 and 2013 to help formulate informed policy regarding net procurement, supplies and replacement. The study was undertaken in three different malaria endemic blocks of Assam during the period of June to October of 2014. The residual bio-efficacies were ascertained using the WHO cone-bioassay method for mosquito mortality post-exposure and corroborated with the ring-net assay for the median knockdown times of both types of LLINs in use by these communities. Cross-sectional community surveys were distributed to assess net ownership, utilization, community practices and the physical conditions of the nets in terms of being torn and the numbers of holes per position. Both the Olyset(®) and PermaNet(®)2.0 LLINs that were distributed in 2009 (i.e., nearly after five years of community usage) were completely torn, worn out and obsolete. However, the LLINs distributed in 2011 (i.e., three years of community usage) retained their residual bio-efficacies in susceptibility ranges that varied from 57% to 79%. However, for the LLINs that were distributed in 2013, the observed residual efficacy was adequate and resulted in a mosquito mortality rate >80 percent. Of the two types of LLINs inspected, the Olyset(®)nets were more durable and robust in terms of being torn less frequently (37.1%, 39/105) compared with the PermaNet(®)2.0 nets (51.8%, 204/394). Regarding the LLINs that were distributed in 2013, all were physically intact and in good condition. The majority of the distributed LLINs (99.2%, 639/644) were still in the possession of the householders of the surveyed populations. This study revealed that the serviceable life of the nets was slightly less than three years in terms of waning residual bio-efficacy and durability that warranted replacement. The communities were aware of the benefits of the use of mosquito net for personal protection and regularly used the nets; thus, LLIN-based interventions for sustained vector control should be scaled up.
Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated wi... more Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated with sequestration caused by cytoadherence of the trophozoite and schizont-infected erythrocytes to the endothelial cells of the deep vascular beds in the brain. Pathophysiology of malaria is complicated by rosetting. Rosetting is a process of binding of uninfected erythrocytes to the erythrocytes infected with mature asexual parasites and is controlled by expression of complement receptor 1 (CR1) on RBC surface. Various polymorphic forms of CR1 are known including molecular weight polymorphism, red blood cell expression levels/density polymorphism and Knops (KN) polymorphism. The Knops blood group includes several allelic pairs; Knops a and b (Kna and Knb), McCoy a and b (McCa, McCb), Swain-Langley (Sla), and Villien (Vil). Knops phenotype Sl (a-) has been found to rosette less effectively than Sl (a+) and hence suggested to be more protective. P. falciparum cases have not reduced much as...
Aedes albopictus is one of the vectors for dengue and chikungunya and emergence of pyrethroid res... more Aedes albopictus is one of the vectors for dengue and chikungunya and emergence of pyrethroid resistance in this species could be of a major concern in controlling the vector. This study reports insecticide susceptibility status of Ae. albopictus to DDT and pyrethroids in some Indian populations and status of presence of knockdown resistance (kdr) mutations. Three to four day old adult female Ae. albopictus collected from Delhi, Gurgaon (Haryana), Hardwar (Uttarakhand), Guwahati (Assam) and Kottayam (Kerala) were bio-assayed with DDT (4%), permethrin (0.75%) and deltamethrin (0.05%) impregnated papers using WHO standard susceptibility test kit. Mosquitoes were PCRgenotyped for F1534C kdr-mutation in the voltage-gated sodium channel (VGSC) gene. DDT and pyrethroid resistant individuals were sequenced for partial domain II, III and IV of VGSC targeting residues S989, I1011, V1016, F1534 and D1794 where kdr mutations are reported in Ae. aegypti. Adult bioassays revealed varying degree ...
The northeastern States of India are co-endemic for Plasmodium falciparum and P. vivax malaria. T... more The northeastern States of India are co-endemic for Plasmodium falciparum and P. vivax malaria. The transmission intensity is low-to-moderate resulting in intermediate to stable malaria. Malaria control prioritized P. falciparum being the predominant and life threatening infection (>70%). P. vivax malaria remained somewhat neglected. The present study provides a status report of P. vivax malaria in the northeastern States of India. Data on spatial distribution of P. vivax from seven northeastern States (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura) were analysed retrospectively from 2008-2013. In addition, cross-sectional malarial surveys were conducted during 1991-2012 in malaria endemic pockets across the States of Assam, Meghalaya, Mizoram and Tripura to ascertain the prevalence of P. vivax in different age groups. Vivax malaria was encountered in all northeastern States but there existed a clear division of two malaria ecotypes supporting ≤30 an...
ABSTRACT The males of the NICD strain of Anopheles stephensi were exposed to 4000 R of Co-60 Gamm... more ABSTRACT The males of the NICD strain of Anopheles stephensi were exposed to 4000 R of Co-60 Gamma radiations at the rate of 188 R per minute and then mated with virgin females of the same age group. The salivary chromosome preparations from 4th instar larvae of F1 progeny revealed 40 heterozygous aberrations involving deletions, inversions, translocations and complex rearrangements, however with variable frequencies. The frequencies of breaks per sperm and the mortality induced, thereof, have been determined. It has been concluded that gamma-rays act specifically but not at random. From the available data, it has been deduced that chromosomes had a spiral structure and polar field type of orientation during the irradiation of spermatozoa.
Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated wi... more Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated with sequestration caused by cytoadherence of the trophozoite and schizont-infected erythrocytes to the endothelial cells of the deep vascular beds in the brain. Pathophysiology of malaria is complicated by rosetting. Rosetting is a process of binding of uninfected erythrocytes to the erythrocytes infected with mature asexual parasites and is controlled by expression of complement receptor 1 (CR1) on RBC surface. Various polymorphic forms of CR1 are known including molecular weight polymorphism, red blood cell expression levels/density polymorphism and Knops (KN) polymorphism. The Knops blood group includes several allelic pairs; Knops a and b (Kna and Knb), McCoy a and b (McCa, McCb), Swain-Langley (Sla), and Villien (Vil). Knops phenotype Sl (a-) has been found to rosette less effectively than Sl (a+) and hence suggested to be more protective. P. falciparum cases have not reduced much as...
The American journal of tropical medicine and hygiene, 2003
The susceptibility of 23 cases of Plasmodium falciparum malaria from the Sonapur primary health c... more The susceptibility of 23 cases of Plasmodium falciparum malaria from the Sonapur primary health center in the Kamrup district of Assam, India to different antimalarials was investigated using the 28-day World Health Organization in vivo test. Whole blood concentrations of chloroquine, sulfadoxine, and quinine were determined at different intervals and at the time of parasites recrudescence after completion of treatment with the respective drugs to confirm the status of drug sensitivity. A case of multi-drug resistant P. falciparum malaria was found where recrudescence occurred, despite standard oral treatment with chloroquine, sulfadoxine/pyrimethamine, and quinine sequentially. Whole blood concentrations of chloroquine, sulfadoxine, and quinine at the time of recrudescence were 0.35 microg/ml (day 7), 18 microg/ml (day 14), and 0.009 microg/ml (day 14), respectively. Therefore, monitoring of drug-resistant P. falciparum malaria and its proper treatment should be intensified to chec...
For diagnosis of malaria, popular brands of rapid test kits collectively termed as &a... more For diagnosis of malaria, popular brands of rapid test kits collectively termed as "dipsticks" were subject to field evaluation in northeastern India for their comparative sensitivity and specificity vis-à-vis conventional microscopic results. Dipsticks based on Plasmodium falciparum-specific histidine-rich protein (Pf HRP-2) antigen capture assay revealed 100% sensitivity and high specificity (94-100%); thus, they were concluded to be reliable tools for confirmed diagnosis of malarial infection. However, an advanced version of the same kit, having incorporated additional pan-malarial monoclonal antibody, was found to be less sensitive (71%) for non-falciparum infections. Besides, Pf HRP-2-based kits continued to show positive results up to day 7, even after clearance of parasitemia on account of persistent antigenemia. This very limitation seemed to have been overcome by parasite-specific lactate dehydrogenase (pLDH) enzyme-based kit. This kit was observed to have high sensitivity (81-89%) and specificity (100%) for both falciparum and non-falciparum malaria, but cannot distinguish mono-infection from mixed infections. It is concluded that the rational use of these kits would accord health benefits in terms of early detection and prompt treatment, reduce drug pressure, and possibly delay the emergence and spread of multi-drug-resistant strains of malarial parasites.
Malaria, particularly due to Plasmodium falciparum, remains a major public health threat in Ethio... more Malaria, particularly due to Plasmodium falciparum, remains a major public health threat in Ethiopia. Artemether-lumefantine (AL) has been the first-line antimalarial drug against uncomplicated P. falciparum malaria in the country since 2004. Regular monitoring of anti-malarial drugs is recommended by the World Health Organization (WHO) to help early detection of drug resistant strains of the parasite and contain their rapid spread. The objective of this study was to assess the therapeutic efficacy of AL in a high-transmission setting in Ethiopia. The study site was Setit Humera, northwest Ethiopia. Single-arm prospective study of a 28-day follow-up was conducted from October 2014 to January 2015 according to the revised WHO 2009 drug efficacy study protocol. Study end-points were classified into primary end-point and secondary end-point. While the primary end-point was the day-28 adequate clinical and parasitological response the secondary end-points were clinical and parasitological evaluations (parasite, fever and gametocyte clearance rate, incidence of drug adverse events) and the relative increment in hemoglobin (Hb) level from baseline to day (D) 14 and D28. A total of 92 patients were enrolled and 79 had completed the 28-day follow-up period. The overall cure rate was 98.8% with 95% confidence interval of 0.915– 0.998 without polymerase chain reaction correction. The parasite clearance rate was high with fast resolution of clinical symptoms; 100% of the study participants cleared parasitae-mia and fever on D3. Gametocyte carriage was reduced from 7% on D0 to 1% on D3 and complete clearance was achieved on D14. Mean Hb concentration significantly increased on D28 compared to that on D14. There was no serious adverse event. AL was efficacious and safe in a high-transmission setting for treatment of uncomplicated falciparum malaria.
(CoH1,N3PS) C, H, S, P, S. L-I1 had bp 114-11.5' (1.6 mm), mp 41-43', 9... more (CoH1,N3PS) C, H, S, P, S. L-I1 had bp 114-11.5' (1.6 mm), mp 41-43', 97 (e 1.7, ... C&). 2,4,6-Tris(~-2-methyI-l-aziridinyl)-s-triazine (o-III).--Csing the method described by S~haefer,~~ 3.1 g (0.055 mole) of D-propyleiiimine was converted to 1.6 g (36%) of 0-11, ...
Indoor, day-resting collections of Anopheles minimus mosquitos from human dwellings in the study ... more Indoor, day-resting collections of Anopheles minimus mosquitos from human dwellings in the study area in Assam, India, indicated that these insects were prevalent throughout the year and that their maximum abundance occurred from March to August. A. minimus was identified as a vector of malaria, and sporozoite infections were recorded every month of the year, with the highest rating occurring in October. The mosquito was highly anthropophilic and fed on human hosts (indoor) all through the night, but feeding was more pronounced between 01:00 and 04:00, the person-biting rate was 13.7 per night. Breeding occurred throughout the year in slow-flowing streams with grassy banks. A. fluviatilis was also identified as a vector of malaria in the study area but occurred in low density, and sporozoite infections were only seasonal.
Anopheles (Cellia) annularis Van der Wulp is a complex of two sibling species provisionally desig... more Anopheles (Cellia) annularis Van der Wulp is a complex of two sibling species provisionally designated as species A and B and can only be differentiated on the basis of the paracentric inversion in the ovarian polytene chromosomes. To analyze the distribution of these two species and to develop a molecular method for the identification of these two cryptic species, we sequenced the ribosomal DNA internal transcribed spacer 2 (ITS2) and domain 3 (D3) of A. annularis specimens collected from Sonapur (Assam), Jabalpur (Madhya Pradesh), Ranchi (Jharkhand), and Ghaziabad (Uttar Pradesh). We did not find any sequence variation among the specimens collected from Assam, Madhya Pradesh, and Jharkhand states, whereas two types of sequences were obtained from the specimens collected from the state of Uttar Pradesh, which correspond to species A and B of the A. annularis complex. Species A was more prevalent among the all four regions studied. The ITS2 sequence of species A showed unique restriction sites for MvaI and Eco24I, while species B displayed HinfI and NruI sites. Similarly, the D3 sequence of species A showed unique restriction site for Alw26I, while species B showed a unique KpnI site. In this study, we report for the first time the development of ribosomal DNA polymerase chain reaction-restriction fragment length polymorphism methods for identifying these two cryptic species of the Annularis complex.
... The situation is further complicated by high proportion of P. falciparum >60%), a killer p... more ... The situation is further complicated by high proportion of P. falciparum >60%), a killer parasite that has become multi-drug resistant (Dua et. al. 2003; Dev et al, 2003). ... Med. Intenl. Hlth.. Vol.1.pp816-819. Dua VK, Dev V, Phookan S, Gupta NC,. Sharma VP, Subbarao SK. 2003. ...
... It is vital to seek greater political commitment for strengthening healthcare services in the... more ... It is vital to seek greater political commitment for strengthening healthcare services in the communities most at risk, and maintaining constant vigil by intensive surveillance and monitoring to avert the impending disease outbreaks for meeting the ... (8.) Jana-Kara BR, Jihullah WA ...
Long-lasting insecticidal nets (LLINs) are being promoted for malaria vector control in the north... more Long-lasting insecticidal nets (LLINs) are being promoted for malaria vector control in the northeastern Indian state of Assam. A cross-sectional study was conducted to assess the current residual bio-efficacy and durability of both the Olyset(®) and PermaNet(®)2.0 LLINs that were distributed earlier in 2009, 2011 and 2013 to help formulate informed policy regarding net procurement, supplies and replacement. The study was undertaken in three different malaria endemic blocks of Assam during the period of June to October of 2014. The residual bio-efficacies were ascertained using the WHO cone-bioassay method for mosquito mortality post-exposure and corroborated with the ring-net assay for the median knockdown times of both types of LLINs in use by these communities. Cross-sectional community surveys were distributed to assess net ownership, utilization, community practices and the physical conditions of the nets in terms of being torn and the numbers of holes per position. Both the Olyset(®) and PermaNet(®)2.0 LLINs that were distributed in 2009 (i.e., nearly after five years of community usage) were completely torn, worn out and obsolete. However, the LLINs distributed in 2011 (i.e., three years of community usage) retained their residual bio-efficacies in susceptibility ranges that varied from 57% to 79%. However, for the LLINs that were distributed in 2013, the observed residual efficacy was adequate and resulted in a mosquito mortality rate >80 percent. Of the two types of LLINs inspected, the Olyset(®)nets were more durable and robust in terms of being torn less frequently (37.1%, 39/105) compared with the PermaNet(®)2.0 nets (51.8%, 204/394). Regarding the LLINs that were distributed in 2013, all were physically intact and in good condition. The majority of the distributed LLINs (99.2%, 639/644) were still in the possession of the householders of the surveyed populations. This study revealed that the serviceable life of the nets was slightly less than three years in terms of waning residual bio-efficacy and durability that warranted replacement. The communities were aware of the benefits of the use of mosquito net for personal protection and regularly used the nets; thus, LLIN-based interventions for sustained vector control should be scaled up.
Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated wi... more Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated with sequestration caused by cytoadherence of the trophozoite and schizont-infected erythrocytes to the endothelial cells of the deep vascular beds in the brain. Pathophysiology of malaria is complicated by rosetting. Rosetting is a process of binding of uninfected erythrocytes to the erythrocytes infected with mature asexual parasites and is controlled by expression of complement receptor 1 (CR1) on RBC surface. Various polymorphic forms of CR1 are known including molecular weight polymorphism, red blood cell expression levels/density polymorphism and Knops (KN) polymorphism. The Knops blood group includes several allelic pairs; Knops a and b (Kna and Knb), McCoy a and b (McCa, McCb), Swain-Langley (Sla), and Villien (Vil). Knops phenotype Sl (a-) has been found to rosette less effectively than Sl (a+) and hence suggested to be more protective. P. falciparum cases have not reduced much as...
Aedes albopictus is one of the vectors for dengue and chikungunya and emergence of pyrethroid res... more Aedes albopictus is one of the vectors for dengue and chikungunya and emergence of pyrethroid resistance in this species could be of a major concern in controlling the vector. This study reports insecticide susceptibility status of Ae. albopictus to DDT and pyrethroids in some Indian populations and status of presence of knockdown resistance (kdr) mutations. Three to four day old adult female Ae. albopictus collected from Delhi, Gurgaon (Haryana), Hardwar (Uttarakhand), Guwahati (Assam) and Kottayam (Kerala) were bio-assayed with DDT (4%), permethrin (0.75%) and deltamethrin (0.05%) impregnated papers using WHO standard susceptibility test kit. Mosquitoes were PCRgenotyped for F1534C kdr-mutation in the voltage-gated sodium channel (VGSC) gene. DDT and pyrethroid resistant individuals were sequenced for partial domain II, III and IV of VGSC targeting residues S989, I1011, V1016, F1534 and D1794 where kdr mutations are reported in Ae. aegypti. Adult bioassays revealed varying degree ...
The northeastern States of India are co-endemic for Plasmodium falciparum and P. vivax malaria. T... more The northeastern States of India are co-endemic for Plasmodium falciparum and P. vivax malaria. The transmission intensity is low-to-moderate resulting in intermediate to stable malaria. Malaria control prioritized P. falciparum being the predominant and life threatening infection (>70%). P. vivax malaria remained somewhat neglected. The present study provides a status report of P. vivax malaria in the northeastern States of India. Data on spatial distribution of P. vivax from seven northeastern States (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura) were analysed retrospectively from 2008-2013. In addition, cross-sectional malarial surveys were conducted during 1991-2012 in malaria endemic pockets across the States of Assam, Meghalaya, Mizoram and Tripura to ascertain the prevalence of P. vivax in different age groups. Vivax malaria was encountered in all northeastern States but there existed a clear division of two malaria ecotypes supporting ≤30 an...
ABSTRACT The males of the NICD strain of Anopheles stephensi were exposed to 4000 R of Co-60 Gamm... more ABSTRACT The males of the NICD strain of Anopheles stephensi were exposed to 4000 R of Co-60 Gamma radiations at the rate of 188 R per minute and then mated with virgin females of the same age group. The salivary chromosome preparations from 4th instar larvae of F1 progeny revealed 40 heterozygous aberrations involving deletions, inversions, translocations and complex rearrangements, however with variable frequencies. The frequencies of breaks per sperm and the mortality induced, thereof, have been determined. It has been concluded that gamma-rays act specifically but not at random. From the available data, it has been deduced that chromosomes had a spiral structure and polar field type of orientation during the irradiation of spermatozoa.
Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated wi... more Plasmodium falciparum is the leading cause of mortality and causes cerebral malaria associated with sequestration caused by cytoadherence of the trophozoite and schizont-infected erythrocytes to the endothelial cells of the deep vascular beds in the brain. Pathophysiology of malaria is complicated by rosetting. Rosetting is a process of binding of uninfected erythrocytes to the erythrocytes infected with mature asexual parasites and is controlled by expression of complement receptor 1 (CR1) on RBC surface. Various polymorphic forms of CR1 are known including molecular weight polymorphism, red blood cell expression levels/density polymorphism and Knops (KN) polymorphism. The Knops blood group includes several allelic pairs; Knops a and b (Kna and Knb), McCoy a and b (McCa, McCb), Swain-Langley (Sla), and Villien (Vil). Knops phenotype Sl (a-) has been found to rosette less effectively than Sl (a+) and hence suggested to be more protective. P. falciparum cases have not reduced much as...
The American journal of tropical medicine and hygiene, 2003
The susceptibility of 23 cases of Plasmodium falciparum malaria from the Sonapur primary health c... more The susceptibility of 23 cases of Plasmodium falciparum malaria from the Sonapur primary health center in the Kamrup district of Assam, India to different antimalarials was investigated using the 28-day World Health Organization in vivo test. Whole blood concentrations of chloroquine, sulfadoxine, and quinine were determined at different intervals and at the time of parasites recrudescence after completion of treatment with the respective drugs to confirm the status of drug sensitivity. A case of multi-drug resistant P. falciparum malaria was found where recrudescence occurred, despite standard oral treatment with chloroquine, sulfadoxine/pyrimethamine, and quinine sequentially. Whole blood concentrations of chloroquine, sulfadoxine, and quinine at the time of recrudescence were 0.35 microg/ml (day 7), 18 microg/ml (day 14), and 0.009 microg/ml (day 14), respectively. Therefore, monitoring of drug-resistant P. falciparum malaria and its proper treatment should be intensified to chec...
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