Evaluation of co-culture of cellulolytic fungi for enhanced cellulase and xylanase activity and saccharification of untreated lignocellulosic material.

Bioethanol production from lignocellulosic materials is hindered by the high costs of pretreatment and the enzymes. The present study aimed to evaluate whether co-cultivation of four selected cellulolytic fungi yields higher cellulase and xylanase activities compared to the monocultures and to investigate whether the enzymes from the co-cultures yield higher saccharification on selected plant materials without thermo-chemical pretreatment. The fungal isolates, Trichoderma reesei F118, Penicillium javanicum FS7, Talaromyces sp. F113, and Talaromyces pinophilus FM9, were grown as monocultures and binary co-cultures under submerged conditions for 7 days. The cellulase and xylanase activities of the culture filtrates were measured, and the culture filtrates were employed for the saccharification of sugarcane leaves, Guinea grass leaves, and water hyacinth stems and leaves. Total reducing sugars and individual sugars released from each plant material were quantified. The co-culture of Talaromyces sp. F113 with Penicillium javanicum FS7 and of T. reesei F118 with T. pinophilus FM9 produced significantly higher cellulase activities compared to the corresponding monocultures whereas no effect was observed on xylanase activities. Overall, the highest amounts of total reducing sugars and individual sugars were obtained from Guinea grass leaves saccharified with the co-culture of T. reesei F118 with T. pinophilus FM9, yielding 63.5% saccharification. Guinea grass leaves were found to be the most susceptible to enzymatic saccharification without pre-treatment, while water hyacinth stems and leaves were the least. Accordingly, the study suggests that fungal co-cultivation could be a promising approach for the saccharification of lignocellulosic materials for bioethanol production.

Curative-Intent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck in Sri Lanka: The Impact of Radiotherapy Technique on Survival.

AIMS: We conducted a retrospective analysis of patients with squamous cell carcinoma of the head and neck (SCCHN) treated with curative-intent radiotherapy at the National Cancer Institute of Sri Lanka to determine the impact of the treatment technique on disease-free survival (DFS). MATERIALS AND METHODS: SCCHN patients treated with radical radiotherapy or adjuvant postoperative radiotherapy from 2016 to 2017 were included in the study. Data on the following variables were collected by reviewing clinical and radiotherapy treatment records: age, gender, tumour site, stage, time to delivery of radiotherapy, use of neoadjuvant chemotherapy, use of concurrent radiosensitising chemotherapy and treatment technique. DFS, defined as the time to death, tumour recurrence or loss to follow-up, was the primary end point and outcomes were compared between patients treated with intensity-modulated radiotherapy (IMRT) in linear accelerators and those treated with conventional radiotherapy in cobalt teletherapy units. Univariate and multivariate analyses were carried out on known prognostic variables. RESULTS: In total, 408 patients were included in the study, with 138 (34%) being treated with IMRT in the linear accelerator. More than 75% of patients were of stage III or IV at diagnosis. The 2-year DFS of the whole cohort was 25% (95% confidence interval 21-30%). Patients treated with IMRT in the linear accelerator had a superior DFS in comparison with those treated with conventional radiotherapy in the cobalt teletherapy units (P < 0.001, hazard ratio 0.64, 95% confidence interval 0.5-0.82). Higher stage, cobalt treatment and use of neoadjuvant chemotherapy were adversely associated with DFS on multivariate analysis. CONCLUSION: A large proportion of patients with SCCHN treated with curative-intent radiotherapy in Sri Lanka had locally advanced disease and DFS was superior in patients treated with IMRT in the linear accelerator.

A study on knowledge, attitudes and practices regarding dengue fever, its prevention and management among dengue patients presenting to a tertiary care hospital in Sri Lanka.

BACKGROUND: The World Health Organization (WHO) has ranked dengue as one of the top ten threats to Global health in 2019. Sri Lanka faced a massive dengue epidemic in 2017, the largest outbreak in the country during the last three decades, consisting of 186,101 reported cases, and over 320 deaths. The epidemic was controlled by intense measures taken by the health sector. However, the reported dengue cases and dengue deaths in 2019 were significantly higher than that of 2018. Deaths were mostly due to delay in hospitalization of severe dengue patients. The mortality of dengue hemorrhagic fever is 2-5% if detected early and treated promptly, but is high as 20% if left untreated. METHODS: A descriptive cross-sectional study was done among patients with dengue fever presenting to the Sri Jayawardenepura General Hospital during October 2019. Data was collected using a questionnaire comprising 20 questions based on knowledge, attitudes and practices on dengue, which were categorized into questions on awareness of mortality and severity of dengue burden, prevention of dengue vector mosquito breeding and acquiring the infection, patient's role in dengue management, and warning signs requiring prompt hospitalization. RESULTS: The mean KAP score on all questions was 55%, while a majority of 65.2% patients scored moderate KAP scores (50-75%) on all questions, and only 7.6% had high KAP scores (> 75%). The highest categorical mean score of 62% was on awareness of dengue prevention, followed by 54% on awareness of dengue burden, and only 51% on dengue management. Only 5.3% patients scored high scores on awareness of dengue management, followed by 28.5%, and 40.9% patients scoring high scores on awareness of dengue burden, and awareness of prevention of dengue respectively. The mean KAP scores on all questions increased with increasing age category. CONCLUSION: The population relatively has a better awareness of dengue prevention, as compared to awareness of dengue mortality and dengue management. The identified weak point is patient awareness of the patients' role in dengue management, and identifying warning signs requiring prompt hospitalization. This results in delay in treatment, which is a major cause for increased mortality. There was a correlation between those who had good knowledge on dengue burden and those who were aware of patients' role in dengue management. An action plan should be implemented to improve public awareness through education programs on the role of the public and patients in dengue management to drive a better outcome.

A young girl with chronic isolated cervical lymphadenopathy found to have lupus lymphadenopathy, progressing to develop lupus nephritis: a case report.

BACKGROUND: Systemic lupus erythematosus is a rare autoimmune disorder, with the prevalence in Asia ranging from 30 to 50/100,000. The diagnosis of systemic lupus erythematosus is made according to the 2019 European League Against Rheumatism/American College of Rheumatology classification criteria, and it does not contain lymphadenopathy as diagnostic criteria. However, lupus lymphadenopathy has an estimated prevalence of 5-7% at the onset of disease, and 12-15% at any stage of the disease. CASE PRESENTATION: A 19-year-old Sinhalese girl had neck nodules since the age of 5 years, which increased in size and became tender since 1 year. She had alopecia and joint stiffness for 6 months. She presented with a 5-day history of worsening joint pain, fever, and painful, enlarging cervical nodules. She had tender cervical lymphadenopathy, and a vasculitic rash on both lower limbs. She had pancytopenia, an erythrocyte sedimentation rate of 92, positive antinuclear antibody titer, and high anti-double-stranded deoxyribonucleic acid (DNA), with low C3 and C4 complements. She had a high reticulocyte count of 5%, with direct and indirect antiglobulin tests being positive, indicating autoimmune hemolytic anemia. Lymph node biopsy showed moderate reactive follicular hyperplasia, with scattered plasma cells and immunoblasts, with varying degree of coagulative necrosis, suggestive of lupus lymphadenopathy. On immunohistochemistry of the lymph node biopsy, Bcl2 was negative, excluding lymphoma. Contrast-enhanced computed tomography of abdomen and chest was normal with no hepatosplenomegaly or lymphadenopathy. Skin biopsy showed leukocytoclastic vasculitis. Later, with development of generalized edema, she was found to have impaired renal function, and renal biopsy showed lupus nephritis. She was started on hydroxychloroquine, prednisolone, and mycophenolate mofetil, and her symptoms improved and lymphadenopathy regressed. CONCLUSION: In the case of cervical lymphadenopathy in a patient with systemic lupus erythematosus, the possibilities of lupus lymphadenopathy, Kikuchi-Fujimoto disease, and lymphoma should all be considered, after excluding secondary infection due to immunosuppression. Histology confirms the differentiation of these pathologies. It is important to differentiate the cause for lymphadenopathy in systemic lupus erythematosus as the outcome and treatment varies. Lupus lymphadenopathy is usually generalized, but isolated cervical lymphadenopathy could also rarely be the first presentation of systemic lupus erythematosus. Lupus lymphadenopathy can be the only presenting feature, and needs a high index in suspecting systemic lupus erythematosus, though it is not included in the diagnostic criteria.

Extensive Bone Marrow Necrosis: A Rare Presentation of Acute Lymphoblastic Leukaemia.

BACKGROUND: Bone marrow necrosis (BMN) is a rare entity which presents with bone pain, fever, and peripheral cytopenia. Acute lymphoblastic leukaemia (ALL) is characterized by malignant proliferation of immature lymphocytes, and patients usually present with fatigue and bleeding manifestations. Presentation with BMN is an extremely rare finding and only few cases had been reported in the literature. Case Presentation. A 22-year-old male presented with nocturnal lower back ache, pleuritic central chest pain, and fever for two weeks. He was extensively investigated for a cause. His investigations revealed pancytopenia with severe neutropenia. Initial bone marrow aspiration and biopsy did not provide a positive result due to extensive necrosis. However, immunohistochemical analysis of few immature lymphoid cells on repeated BM biopsy showed evidence of acute lymphoblastic leukaemia. CONCLUSIONS: ALL usually presents with fatigue and bleeding manifestations. Presentation with BMN is extremely rare. The diagnosis was extremely challenging as this patient had only occasional atypical cells in the peripheral blood film and the repeat bone marrow (BM) biopsy showed extensive necrosis.

Palliative care consultation and aggressive care at end of life in unresectable pancreatic cancer.

Background: Palliative care (pc) consultation has been associated with less aggressive care at end of life in a number of malignancies, but the effect of the consultation timing has not yet been fully characterized. For patients with unresectable pancreatic cancer (upcc), aggressive and resource-intensive treatment at the end of life can be costly, but not necessarily of better quality. In the present study, we investigated the association, if any, between the timing of specialist pc consultation and indicators of aggressive care at end of life in patients with upcc. Methods: This retrospective cohort study examined the potential effect of the timing of specialist pc consultation on key indicators of aggressive care at end of life in all patients diagnosed with upcc in Nova Scotia between 1 January 2010 and 31 December 2015. Statistical analysis included univariable and multivariable logistic regression. Results: In the 365 patients identified for inclusion in the study, specialist pc consultation was found to be associated with decreased odds of experiencing an indicator of aggressive care at end of life; however, the timing of the consultation was not significant. Residency in an urban area was associated with decreased odds of experiencing an indicator of aggressive care at end of life. We observed no association between experiencing an indicator of aggressive care at end of life and consultation with medical oncology or radiation oncology. Conclusions: Regardless of timing, specialist pc consultation was associated with decreased odds of experiencing an indicator of aggressive care at end of life. That finding provides further evidence to support the integral role of pc in managing patients with a life-limiting malignancy.

Incidence of inflammatory bowel disease in Gampaha district: details of the Sri Lankan component of the Asia-Pacific Crohn's and colitis epidemiology study.

The aim of this report is to provide details of the methodology and results of the Sri Lankan component of the Asia-Pacific Crohn's and Colitis Epidemiology Study. Fourteen state and private hospitals with specialist services in the Gampaha and Colombo districts were kept under surveillance over a 12 month period to recruit patients with newly diagnosed Inflammatory Bowel Disease (IBD) who were permanent residents of the Gampaha district. Thirty five cases (ulcerative colitis-21, Crohn's disease-13, IBD-undetermined-1) were detected, giving a crude annual IBD incidence of 1.59 per 100,000 population.

Concurrent outbreaks of Chikungunya and Dengue fever in Kandy, Sri Lanka, 2006-07: a comparative analysis of clinical and laboratory features.

OBJECTIVES: To compare the clinical and laboratory features of confirmed cases of Chikungunya and Dengue fever; to validate the clinical diagnosis based on serology. METHODS: Cases with a clinical diagnosis of Chikungunya and Dengue fever were recruited for seroconfirmation during a concurrent epidemic in 2006-07, at the General Hospital, Peradeniya, Sri Lanka. RESULTS: Of 54 patients with fever, serology confirmed 21 with Chikungunya infection, 20 with Dengue infection, and three co-infections, with sensitivity of the clinical diagnosis of 92% for Chikungunya fever and 95% for Dengue fever. The mean age of patients with Chikungunya fever was 45 years (range 21-74 years), and patients with Dengue fever was 30 years (range 15-63 years) (p = 0.005). Sixteen (70%) of Chikungunya fever patients were females, while 15 (71%) of those with Dengue fever were males (p = 0.007). Arthralgia was common to both groups (p = 0.155), while headache and a bleeding tendency were observed more in patients with Dengue fever. Twelve (57%) Chikungunya cases had acute arthritis compared with none in the Dengue group (p = 0.001), lasting mean 6 days (range 1-14 days). They developed chronic arthritic disability (range 1-6 months). Leucopenia was common to both Chikungunya and Dengue fever patients. However, thrombocytopenia was more pronounced in the Dengue patients (mean (SD) platelet count 75 (34)x10(9)/l) than in the Chikungunya patients (117 (70)x10(9)/l) (p = 0.001). In the Chikungunya group there was a positive correlation between duration of the illness and the platelet count (r = 0.181, p = 0.194), but the Dengue group showed a negative correlation (r = -0.309, p<0.001). CONCLUSION: Most of the clinical and laboratory features of patients with Chikungunya and Dengue fever are similar. Arthritis is the pathognomonic sign in patients with Chikungunya fever.

Cumulative sum (CUSUM) analysis in the assessment of trainee competence in fetal biometry measurement.

OBJECTIVE: To determine the value of cumulative sum (CUSUM) analysis in assessing trainee proficiency in fetal biometry measurement. METHODS: Three primary healthcare doctors with no prior ultrasound training were recruited. Each trainee measured the fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) on 100 consecutive pregnant women. The supervisor repeated the measurements. The CUSUM for each set of trainee measurements was calculated at a set failure rate of 10%. The point at which the graph fell below two consecutive boundary lines indicated the number of examinations required to achieve competence. RESULTS: The CUSUM graphs showed that the rate of learning measurement skills varied among the three trainees. The graph for the CUSUM series for BPD and HC measurement for all trainees fell below two consecutive boundary lines and remained there, indicating competence. The CUSUM series for AC measurement for two of the trainees indicated that competence was achieved; however, for the third trainee, while the graph fell below two consecutive boundary lines, indicating competence, it rose again, crossing two consecutive boundary lines. This indicated a loss of competence and the need for further training. FL measurements for the same trainee never fell below two consecutive boundary lines, indicating failure to achieve competence; the other two achieved competence, but failed to maintain it. CONCLUSIONS: CUSUM is a useful tool for identifying points of competence and for quantifying the duration of ultrasound training required for each trainee. It provides an early indication of performance, and highlights difficulties in individual performance.

The effect of intermittent maternal fasting on human fetal breathing movements.

In order to determine the effect of maternal fasting on human fetal breathing movements (FBM), 63 healthy pregnant women with singleton uncomplicated pregnancies of 30 weeks' gestation or more, and who were fasting during Ramadan, were recruited. Maternal blood glucose level and fetal movements were recorded during and after fasting. Statistical comparison of samples before and after a meal was made using Wilcoxon's signed-ranks test. Maternal glucose level during fasting (5.1 +/- 0.5 mmol/l) was significantly (P = 0.01) lower than after breakfast (5.3 +/- 1.0 mmol/l). There was a significant association between maternal glucose levels and numbers of days faster (P = 0.01). The time needed to detect breathing movements was significantly longer (P = 0.005) during fasting than postprandial. The continuous variety of fetal breathing movement was significantly (P = 0.02) less during fasting compared to postprandial. It is concluded that intermittent maternal fasting is associated with a significant alteration in the frequency and pattern of human FBM.

Impact of a limited fluoroquinolone reimbursement policy on antimicrobial prescription claims.

OBJECTIVE: To examine the influence on administrative pharmacy claims of a policy that limited the reimbursement of the fluoroquinolones and other antimicrobials in the senior population within Nova Scotia, Canada. METHODS: The administrative claims database of the Nova Scotia Seniors' Pharmacare Program was used to identify all prescription claims for orally administered antibiotics and urinary antiinfectives. The number of beneficiaries receiving antimicrobials and the number, duration, and cost of prescriptions for antimicrobials were measured monthly. Descriptive time-series plots were used to compare antimicrobial use for two 12-month periods before the institution of the policy (December 1, 1994-November 30, 1995, and December 1, 1995-November 30, 1996) and the 12 months after the policy took effect (January 1, 1997-December 31, 1997). RESULTS: Following the implementation of the fluoroquinolone reimbursement policy, the number of patients using antimicrobials decreased by 2.2% and the number of prescriptions for antimicrobials decreased by 3.4%. Fluoroquinolone prescriptions decreased by 80.2%; prescriptions for sulfonamides and trimethoprim increased by 34.9%, cephalosporins by 17.0%, and macrolides and lincosamides by 16.5%. The only prescription duration to change was the fluoroquinolones, which increased by 25%. The average cost per antimicrobial user/year decreased from $35.24 during prepolicy period 2 to $27.51 during the postpolicy period. CONCLUSIONS: Prescription claims for fluoroquinolones in seniors decreased following the introduction of the policy. Total antimicrobial use also decreased, although this may be related to other factors. The effect of this policy change on patient outcomes requires further study.

Incidence of cancer in Sydney and Cape Breton County, Nova Scotia 1979-1997.

The primary purpose of this study was to assess whether Sydney, Industrial Cape Breton County excluding Sydney (ICBxS) and Cape Breton County (CBCo) residents were at increased risk for cancer compared to Nova Scotia (NS) residents over five-year periods during 1979 through 1997. Gender-stratified, age-standardized cancer incidence rates were calculated following the direct method. All-cause rates were higher for female and male residents of Sydney, ICBxS and CBCo compared to NS based upon both municipality and postal code methods of residence classification. A sensitivity analysis of residential coding yielded a high degree of consistency for all geographies except Sydney, limiting comparisons of Sydney rates with other local geographies except where consistencies were observed. The results of this ecological study support the need for further analysis of factors contributing to the increased risk for cancer in CBCo.

The health and nutritional status of school children in two rural communities in Sri Lanka.

There is growing evidence of considerable burden of morbidity and mortality due to infectious diseases and undernutrition in school children. This study describes the nutritional status and parasitic infections of school children in two areas of rural Sri Lanka. All children in four primary schools in the Moneragala district of Sri Lanka were included in the study. The height and weight of children were measured and anthropometric indices calculated. Stool and blood samples were examined for evidence of intestinal helminthiasis, malaria and anaemia. A greater proportion of boys than girls were underweight, wasted and stunted. Over 80% of the children were anaemic but did not apparently have iron deficiency anaemia according to their blood picture. The prevalence of parasitic infections such as hookworm and Plasmodium spp that may contribute to anaemia was low.

Enhancement of survival of stored dopaminergic cells and promotion of graft survival by exposure of human fetal nigral tissue to glial cell line--derived neurotrophic factor in patients with Parkinson's disease. Report of two cases and technical considerations.

The authors have studied the ability of glial cell line-derived neurotrophic factor (GDNF) to promote survival of human fetal dopaminergic tissue after a storage period of 6 days and subsequent implantation into the human putamen. The results indicate that GDNF promotes survival of stored dopaminergic cells. Cells stored without GDNF had a 30.1% decrease in survival time compared with those exposed to GDNF. Two patients with Parkinson's disease received bilateral putaminal implants of fetal dopaminergic cells exposed to GDNF for 6 days and showed enhancement of graft survival as assessed by positron emission tomography scanning. A mean increase of 107% in putaminal fluorodopa uptake from baseline values was observed 12 months postgrafting.

The dietary habits of idiopathic calcium stone-formers and normal control subjects.

OBJECTIVES: To examine the relationship between 12 macro- and micro-nutrients and the risk of recurrent calcium stone formation by comparing the diets of a large outpatient clinic-based group of patients who had formed calcium-based urinary tract calculi with that of a population-based control group matched for age, gender and body mass index. PATIENTS, SUBJECTS AND METHODS: The dietary intake of 500 patients (cases) randomly selected from the adult population attending an outpatient renal-stone clinic and being evaluated and/or treated for biochemically or radiologically diagnosed calcium-based upper urinary tract calculi were compared with those of 500 control subjects selected to match for age, sex and body mass index from a stratified probability sample of 2212 adults (not institutionalized) living in the same geographical area. RESULTS: Comparing the mean nutritional intakes showed a statistically higher consumption of energy, carbohydrates, sodium, fibre, vitamin C, fat and folic acid among cases than in controls. The intake of calcium, alcohol and vitamin A was significantly higher among the controls. There were no significant differences in the intake of protein, niacin or iron. The results of these comparisons varied when the groups were stratified by sex, age and body mass index. CONCLUSIONS: Dietary risk factors for calcium-based urinary tract calculi are many and complex, and a detailed consideration of sex, age and body mass index is important in interpreting such data. While it is difficult to draw firm conclusions about causes and effects of individual nutrients from the available data, this study indicates a possibly more important role for dietary fat in stone formation than has been previously recognized. This relationship needs to be further explored in relation to urinary risk factors, as it may be possible to advise patients to reduce dietary fat as a prophylactic measure for stone formation. As dietary fat has been associated with cardiovascular diseases and possibly cancer, an overall recommendation to these patients for a low dietary fat intake may be easier to follow.

Self-assessment of disease activity by patients with rheumatoid arthritis.

OBJECTIVE: To determine the reliability of self-assessment of disease by patients with rheumatoid arthritis (RA), with a particular emphasis on the assessment of articular swelling. METHODS: A questionnaire was developed using components from validated instruments. Information was obtained on global function, global joint tenderness/swelling, and joint pain (10 cm visual analog scales), duration of musculoskeletal morning stiffness (grade 1-6), ACR functional score (grade 1-4), tender joint count (0-20), tender joint score (0-60), swollen joint count (0-20), and swollen joint score (0-60). Data were collected prospectively on 61 patients with RA in a teaching clinic or office practice by 4 staff rheumatologists. Patient questionnaires were completed within 24 h before physician assessments. Followup assessments were carried out on 27 patients after a mean interval of 3 months (range 0.5-6). RESULTS: At the initial assessment there was a significant correlation between patient and physician assessments for global function (r = 0.83; p = 0.01) [intraclass correlation coefficient (ICC) = 0.83; p < 0.01], global joint tenderness/swelling (r = 0.83; p < 0.01) (ICC = 0.83; p < 0.01), global joint pain (r = 0.83; p < 0.01) (ICC = 0.81; p < 0.01), duration of morning stiffness (r = 0.83; p < 0.01) (ICC = 0.85; p < 0.01), ACR functional score (r = 0.61; p < 0.01) (ICC = 0.62; p < 0.01), tender joint count (r = 0.57; p < 0.01) (ICC = 0.31; p < 0.01), and tender joint score (r = 0.60; p < 0.01) (ICC = 0.35; p < 0.01). However, there was poor correlation between patient and physician assessments for both swollen joint count (r = 0.16; p > 0.05) (ICC = -0.02; p > 0.05) and swollen joint score (r = 0.24; p > 0.05) (ICC = 0.12; p > 0.05). Longitudinal analysis indicated significant correlation between changes in patient and physician assessments in all variables except swollen joint count and score. CONCLUSION: Although there was good correlation between most variables for patient and physician assessments of disease activity in RA, there were substantial differences in the assessment of joint swelling. This objective determinant of disease activity cannot be ascertained in self-report measures of health status.

Features of recrudescent chloroquine-resistant Plasmodium falciparum infections confer a survival advantage on parasites and have implications for disease control.

This paper reports on the features of recrudescent infections of chloroquine-resistant Plasmodium falciparum (CQRPf) malaria from a study in vivo of patients from a malaria endemic (n = 527) and non-endemic (n = 129) region of Sri Lanka where the incidence of RI resistance was 30% and 55%, respectively. In both groups of patients, the recrudescent infections which emerged after treatment of the primary infection with chloroquine (CQ) and primaquine had significantly lower peripheral parasitaemia (0.036% and 0.108% in endemic and non-endemic patients, respectively) compared to their primary infections (mean parasitaemia 0.13% and 0.49%; P = 0.021 and 0.002, respectively). The recrudescences of CQ resistant infections also gave rise to clinical disease of markedly reduced severity (average clinical scores of 10.1 and 8.2) compared to their primary infections (average clinical scores of 12.4 and 12.3; P = 0.003 and 0.001, respectively, in endemic and non-endemic patients). CQ resistant recrudescent infections therefore had a lower probability of being diagnosed and treated. In endemic patients, a higher proportion of CQRPf infections (57%) had gametocytaemia compared to the chloroquine sensitive ones (29%) (P = 0.014, chi 2 = 5.96) and were significantly more infective to mosquitoes (P = 0.047). these findings imply that, in areas where CQ resistance is prevalent, the continued use of the drug may confer a survival and propagation advantage on resistant parasites and favour the rapid expansion of their reservoir. In support of this, we also present epidemiological evidence showing that, in endemic areas, the proportion of P. falciparum patients carrying gametocytes has increased significantly since the emergence of chloroquine resistance. These findings are relevant to the management of drug resistance and malaria control in countries where P.falciparum is only partially resistant to CQ.