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This longitudinal comparative study investigated the effect of preventive chemotherapy (PC) on covert tissue changes associated with lymphatic filariasis (LF) among young people living in an LF-endemic area in Myanmar.Tissue compressibility and extracellular free fluid in the lower limbs of people aged 10-21 years were measured using indurometry and bioimpedance spectroscopy (BIS). Baseline measures were taken in October 2014, annual mass drug administration (MDA) of PC was delivered in December, and in March 2015 further PC was offered to LF-positive cases who had missed MDA. Follow-up measures were taken in February and June 2015.A total of 50 antigen-positive cases and 46 antigen-negative controls were included. Self-reported PC consumption was 60.1% during 2014 MDA and 66.2% overall. At second follow-up, 24 of 34 cases and 27 of 43 controls had consumed PC. Significant and clinically relevant between-group differences at baseline were not found post-PC. Bayesian linear mixed models showed a significant change in indurometer scores at both calves for antigen-positive cases who consumed any PC (dominant calf: -0.30 [95% CI -0.52, -0.07], P 0.05 and non-dominant calf: -0.35 [95% CI -0.58, -0.12], P 0.01). Changes in antigen-negative participants or those not consuming PC were not significant.This study is the first attempt to use simple field-friendly tools to track fluid and tissue changes after treatment of asymptomatic people infected with LF. Results suggested that PC alone is sufficient to reverse covert lymphatic disturbance. Longer follow-up of larger cohorts is required to confirm these improvements and whether they persist over time. These findings should prompt increased efforts to overcome low PC coverage, which misses many infected young people, particularly males, who are unaware of their infection status, unmotivated to take PC and at risk of developing lymphoedema. Indurometry and BIS should be considered in assessment of lymphatic filariasis-related lymphedema.Cette étude comparative longitudinale a investigué l'effet de la chimiothérapie préventive (CP) sur les modifications tissulaires cachées associées à la filariose lymphatique (FL) chez les jeunes vivant dans une zone d'endémie pour la FL au Myanmar. MÉTHODES: La compressibilité des tissus et le liquide libre extracellulaire dans les membres inférieurs des personnes âgées de 10 à 21 ans ont été mesurés par indurométrie et spectroscopie de bioimpédance (BIS). Les mesures de base ont été prises en octobre 2014, la distribution en masse de médicament (DMM) annuelle a été administrée en décembre et en mars 2015, et une CP additionnelle a été offerte aux cas positifs pour la FL qui avaient manqué la DMM. Des mesures de suivi ont été prises en février et juin 2015. RÉSULTATS: 50 cas positifs pour l'antigène et 46 témoins négatifs ont été inclus. L'administration de CP auto-déclarée était de 60,1% durant la DMM de 2014 et de 66,2% au total. Au deuxième suivi, 24 des 34 cas et 27 des 43 témoins avaient pris la CP. Des différences significatives et cliniquement pertinentes entre les groupes au départ n'ont pas été trouvées après la CP. Les modèles mixtes linéaires bayésiens ont montré un changement significatif des scores d'indurometrie aux deux mollets pour les cas positifs pour l'antigène qui prenaient une CP (mollet dominant: -0,30 [IC95%: -0,52, -0,07], p0,05, mollet non dominant: - 0,35 [IC95%: -0,58, -0,12], p0,01). Les changements chez les participants négatifs pour l'antigène ou ceux qui ne prenaient pas de CP n’étaient pas significatifs.Cette étude est la première tentative d'utilisation d'outils simples, conviviaux sur le terrain, pour suivre les modifications du tissu conjonctif après le traitement de personnes asymptomatiques infectées par la FL. Les résultats suggèrent que la CP seule est suffisante pour inverser les modifications lymphatiques cachées. Un suivi plus long de plus grandes cohortes est nécessaire pour confirmer ces améliorations et déterminer si elles persistent ou non. Ces résultats devraient inciter à redoubler d'efforts pour surmonter la faible couverture en CP, qui rate beaucoup de jeunes infectés, en particulier les hommes, qui ne sont pas au courant de leur statut d'infection, qui ne sont pas motivés pour prendre une CP et risquent de développer un lymphœdème. L'indurométrie et la BIS devraient être considérées dans l’évaluation du lymphoedème associé à la filariose lymphatique.

Background: Plasmodium vivax liver stages (hypnozoites) may cause relapses, prolonging morbidity, and impeding malaria control and elimination. The World Health Organization (WHO) recommends three schedules for primaquine: 0.25 mg/kg/day (standard), or 0.5 mg/kg/day (high standard) for 14 days, or 0.75 mg/kg once weekly for eight weeks, all of which can be difficult to complete. Since primaquine can cause haemolysis in individuals with glucose‐6‐phosphate dehydrogenase (G6PD) deficiency, clinicians may be reluctant to prescribe primaquine without G6PD testing, and recommendations when G6PD status is unknown must be based on an assessment of the risks and benefits of prescribing primaquine. Alternative safe and efficacious regimens are needed. Objectives: To assess the efficacy and safety of alternative primaquine regimens for radical cure of P vivax malaria compared to the standard or high‐standard 14‐day courses. Search methods: We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (PubMed); Embase (Ovid); LILACS (BIREME); WHO International Clinical Trials Registry Platform and ClinicalTrials.gov up to 2 September 2019, and checked the reference lists of all identified studies. Selection criteria: Randomized controlled trials (RCTs) of adults and children with P vivax malaria using either chloroquine or artemisinin‐based combination therapy plus primaquine at a total adult dose of at least 210 mg, compared with the WHO‐recommended regimens of 0.25 or 0.5 mg/kg/day for 14 days. Data collection and analysis Two review authors independently assessed trial eligibility and quality, and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous data. We grouped efficacy data according to length of follow‐up, partner drug, and trial location. We analysed safety data where included. Main results: 0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days There may be little or no difference in P vivax recurrences at six to seven months when using the same total dose (210 mg adult dose) over seven days compared to 14 days (RR 0.96, 95% CI 0.66 to 1.39; 4 RCTs, 1211 participants; low‐certainty evidence). No serious adverse events were reported. We do not know if there is any difference in the number of adverse events resulting in discontinuation of primaquine (RR 1.04, 95% CI 0.15 to 7.38; 5 RCTs, 1427 participants) or in the frequency of anaemia (RR 3.00, 95% CI 0.12 to 72.91, 1 RCT, 240 participants) between the shorter and longer regimens (very low‐certainty evidence). Three trials excluded people with G6PD deficiency; two did not provide this information. Pregnant and lactating women were either excluded or no details were provided. High‐standard 0.5 mg/kg/day for 14 days versus standard 0.25 mg/kg/day for 14 days There may be little or no difference in P vivax recurrences at six months with 0.5 mg/kg/day primaquine for 14 days compared to 0.25 mg/kg/day for 14 days (RR 0.84 (95% CI 0.49 to 1.43; 2 RCTs, 677 participants, low‐certainty evidence). No serious adverse events were reported. We do not know whether there is a difference in adverse events resulting in discontinuation of treatment with the high‐standard dosage (RR 4.19, 95% CI 0.90 to 19.60; 1 RCT, 778 participants, very low‐certainty evidence). People with G6PD deficiency and pregnant or lactating women were excluded. 0.75 mg/kg/week for eight weeks versus high‐standard 0.5 mg/kg/day for 14 days We do not know whether weekly primaquine increases or decreases recurrences of P vivax compared to high‐standard 0.5 mg/kg/day for 14 days, at 11 months' follow‐up (RR 3.18, 95% CI 0.37 to 27.60; 1 RCT, 122 participants; very low‐certainty evidence). No serious adverse events and no episodes of anaemia were reported. G6PD‐deficient patients were not randomized but included in the weekly primaquine group (only one patient detected). 1 mg/kg/day for seven days versus high standard 0.5 mg/kg/day for 14 days There is probably little or no difference in P vivax recurrences at 12 months between 1.0 mg/kg/day primaquine for seven days and the high‐standard 0.5 mg/kg/day for 14 days (RR 1.03, 95% CI 0.82 to 1.30; 2 RCTs, 2526 participants; moderate‐certainty evidence). There may be moderate to large increase in serious adverse events in the 1.0 mg/kg/day primaquine for seven days compared with the high‐standard 0.5 mg/kg/day for 14 days, during 42 days follow‐up (RR 12.03, 95% CI 1.57 to 92.30; 1 RCT, 1872 participants, low‐certainty evidence). We do not know if there is a difference between 1.0 mg/kg/day primaquine for seven days and high‐standard 0.5 mg/kg/day for 14 days in adverse events that resulted in discontinuation of treatment (RR 2.50, 95% CI 0.49 to 12.87; 1 RCT, 2526 participants, very low‐certainty evidence), nor if there is difference in frequency of anaemia by 42 days (RR 0.93, 95% CI 0.62 to 1.41; 2 RCTs, 2440 participants, very low‐certainty evidence). People with G6PD deficiency were excluded. Other regimens: Two RCTs evaluated other rarely‐used doses of primaquine, one of which had very high loss to follow‐up. Adverse events were not reported. People with G6PD deficiency and pregnant or lactating women were excluded. Authors' conclusions: Trials available to date do not detect a difference in recurrence between the following regimens: 1) 0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days; 2) high‐standard 0.5 mg/kg/day for 14 days versus standard 0.25 mg/kg/day for 14 days; 3) 0.75 mg/kg/week for eight weeks versus high‐standard 0.5 mg/kg/day for 14 days; 4) 1 mg/kg/day for seven days versus high‐standard 0.5 mg/kg/day for 14 days. There were no differences detected in adverse events for Comparisons 1, 2 or 3, but there may be more serious adverse events with the high seven‐day course in Comparison 4. The shorter regimen of 0.5 mg/kg/day for seven days versus standard 0.25 mg/kg/day for 14 days may suit G6PD‐normal patients. Further research will help increase the certainty of the findings and applicability in different settings.

Objective: Papua New Guinea (PNG) has an emerging tuberculosis (TB) epidemic which has become a national public health priority. In Western Province, there are few data about TB outside Daru and the South Fly District. This study describes the epidemiology of TB diagnosed at Balimo District Hospital (BDH) in the Middle Fly District of Western Province, PNG. Methods: All patients (n = 1614) diagnosed with TB at BDH from April 2013 to February 2017 were recorded. Incidence of reported new cases was calculated for the combined Balimo Urban and Gogodala Rural local level government areas. Analyses investigated patient demographic and clinical information, differences between pulmonary and extrapulmonary TB patients, and predictors of treatment failure. Results: The average case notification rate (2014–2016) was 727 TB cases per 100 000 people per year. One-quarter of TB cases were in children, and 77.1% of all cases had an extrapulmonary TB diagnosis. There was a 1:1.1 ratio of female to male TB cases. When comparing pulmonary and extrapulmonary TB patients, extrapulmonary TB was more likely in those aged up to 14 years and over 54 years. Extrapulmonary TB was more likely in new patients, and pulmonary TB more likely in previously treated patients. Residence in rural regions was associated with treatment failure. Conclusion: There is a high burden of TB in the Balimo region, including a very high proportion of extrapulmonary TB. These factors emphasise the importance of BDH as the primary hospital for TB cases in the Balimo region and the Middle Fly District, and the need for resources and staff to manage both drug-susceptible and drug-resistant TB cases.

Objective: To assess the effectiveness of impregnated mosquito nets, indoor residual spraying and larval control relative to the impacts of climate variability in the decline of malaria cases in Eritrea. Methods: Monthly data on clinical malaria cases by subzoba (district) in three zobas (zones) of Eritrea for 1998–2003 were used in Poisson regression models to determine whether there is statistical evidence for reduction in cases by DDT, malathion, impregnated nets and larval control used over the period, while analysing the effects of satellite-derived climate variables in the same geographic areas. Results: Both indoor residual spraying (with DDT or malathion) and impregnated nets were independently and significantly negatively associated with reduction in cases, as was larval control in one zoba. Malaria cases were significantly positively related to differences in current and previous months’ vegetation (NDVI) anomalies. The relationship to rainfall differences 2 and 3 months previously was also significant, but the direction of the effect varied by zoba. Standardized regression coefficients indicated a greater effect of climate in the zoba with less intense malaria transmission. Conclusion: The results support the view that both indoor residual spraying and impregnated nets have been independently effective against malaria, and that larval control was also effective in one area. Thus climate, while significant, is not the only explanation for the recent decline in malaria cases in Eritrea. If appropriate statistical approaches are used, routine surveillance data from cases attending health facilities can be useful for assessing control programme success and providing estimates of the effectiveness of individual control measures. Effectiveness estimates suitable for use in cost-effectiveness analysis have been obtained.

Six mosquito species were identified in a survey of containers associated with 347 households in four villages in American Samoa. Aedes polynesiensis Marks (Diptera: Culicidae) and Aedes aegypti (L) were the most abundant species, representing 57% and 29% of the mosquitoes identified. Culex quinquefasciatus (Say), Culex annulirostris (Skuse), Aedes oceanicus (Belkin) and Toxorhynchites amboinensis (Doleschall) were also found. Aedes aegypti and Ae. polynesiensis showed distinct differences in their use of containers, preferring large and small containers, respectively. By contrast with previous studies, Ae. polynesiensis utilized domestic and natural containers with equal frequency, whereas Ae. aegypti continued to be found predominantly in domestic containers. Only 15% of containers holding immature mosquitoes included pupae and fewer than 10 Aedes spp. pupae were found in most containers with pupae. An estimated 2289 Ae. polynesiensis and 1640 Ae. aegypti pupae were found in 2258 containers. The presence of both species in the same container did not affect the mean density of either species for larvae or pupae. Glass jars, leaf axils, tree holes and seashells produced few Aedes spp. pupae in any of the study villages. Overall, 75% of Ae. polynesiensis pupae were found in buckets, ice-cream containers and tyres, with

Background: Cholera is a cause of acute watery diarrhoea which can cause dehydration and death if not adequately treated. It usually occurs in epidemics, and is associated with poverty and poor sanitation. Effective, cheap, and easy to administer vaccines could help prevent epidemics. Objectives: To assess the effectiveness and safety of oral cholera vaccines in preventing cases of cholera and deaths from cholera. Search methods: In October 2010, we searched the Cochrane Infectious Disease Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; LILACS; the metaRegister of Controlled Trials (mRCT), and the WHO International Clinical Trials Registry Platform (ICTRP) for relevant published and ongoing trials. Selection criteria: Randomized or quasi-randomized controlled trials of oral cholera vaccines in healthy adults and children. Data collection and analysis: Each trial was assessed for eligibility and risk of bias by two authors working independently. Data was extracted by two independent reviewers and analysed using the Review Manager 5 software. Outcomes are reported as vaccine protective efficacy (VE) with 95% confidence intervals (CIs). Main results: Seven large efficacy trials, four small artificial challenge studies, and 29 safety trials contributed data to this review. Five variations of a killed whole cell vaccine have been evaluated in large scale efficacy trials (four trials, 249,935 participants). The overall vaccine efficacy during the first year was 52% (95% CI 35% to 65%), and during the second year was 62% (95% CI 51% to 62%). Protective efficacy was lower in children aged less than 5 years; 38% (95% CI 20% to 53%) compared to older children and adults; 66% (95% CI 57% to 73%). One trial of a killed whole cell vaccine amongst military recruits demonstrated 86% protective efficacy (95% CI 37% to 97%) in a small epidemic occurring within 4 weeks of the 2-dose schedule (one trial, 1426 participants). Efficacy data is not available beyond two years for the currently available vaccine formulations, but based on data from older trials is unlikely to last beyond three years. The safety data available on killed whole cell vaccines have not demonstrated any clinically significant increase in adverse events compared to placebo. Only one live attenuated vaccine has reached Phase III clinical evaluation and was not effective (one trial, 67,508 participants). Two new candidate live attenuated vaccines have demonstrated clinical effectiveness in small artificial challenge studies, but are still in development. Authors' conclusions: The currently available oral killed whole cell vaccines can prevent 50 to 60% of cholera episodes during the first two years after the primary vaccination schedule. The impact and cost-effectiveness of adopting oral cholera vaccines into the routine vaccination schedule of endemic countries will depend on the prevalence of cholera, the frequency of epidemics, and access to basic services providing rapid rehydration therapy.

Background: Injected cholera vaccines are rarely used today, although they may have some benefit. It is valuable to summarize the evidence for effectiveness of injected cholera vaccines for comparison with newer oral vaccines (subject of a separate Cochrane Review). Objectives: To evaluate killed whole cell (KWC) cholera vaccines and other inactive subunit vaccines (administered by injection) for preventing cholera and death, and to evaluate the adverse effects. Search methods: In September 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), EMBASE, and LILACS. We also searched reference lists and handsearched the journal Vaccine up to 1997. Selection criteria: Randomized and quasi-randomized controlled trials comparing injected cholera vaccines (KWC or other inactive subunit) with placebo, control vaccines, or no intervention in adults and children irrespective of immune status or special risk category. Data collection and analysis: Two authors extracted data and assessed trial methodological quality independently. Dichotomous data were reported using the risk ratio (RR) with 95% confidence intervals (CI). Vaccine efficacies were also calculated (% vaccine efficacy = (1-RR) x 100%). Main results: Sixteen trials, involving over one million adults, children and infants, fulfilled the inclusion criteria. Twenty-four comparisons reported on vaccine efficacy (cholera cases and/or deaths) and 11 comparisons considered adverse effects (nine reported on both). Compared to placebo, vaccinees had a reduced risk of death from cholera (RR 0.49, 95% CI 0.25 to 0.93; 837,442 participants) and a reduced risk of contracting cholera at 12 months (RR 0.52, 95% CI 0.42 to 0.65, random-effects model; 1,512,573 participants). This translates to an efficacy of 48%, 95% confidence interval 35% to 58%. Significant protection lasted for two years, even after only a single dose, and for three years with an annual booster. Children over five years and adults were protected for up to three years, while children under five years were protected for up to a year. Injected cholera vaccines were associated with more systemic and local adverse effects compared to placebo, but these were not severe or life-threatening. Authors' conclusions: Injected cholera vaccines appear to be safe and relatively more effective than usually realized. Protection against cholera persists for up to two years following a single dose of vaccine, and for three years with an annual booster. However, they have been superseded by oral vaccines.

We have studied the properties of epitopes on Plasmodium falciparum gamete surface protein Pfs 48/45, a target antigen of malaria transmission blocking antibodies. Using a two site immunoradiometric assay we have defined three spacially separate, non-repeated, epitope regions on the peptides representing this antigen. Epitope region I is a target of monoclonal antibodies (MoAbs) which strongly suppress infectivity of gametocytes of P. falciparum to mosquitoes; the effect is complement independent and is mediated as effectively by the monovalent Fab fragments as by intact MoAb. Epitope region II consists of two spacially close subregions, IIa and IIb; variant forms of epitopes IIa and IIb occurred in different isolates of P. falciparum. Epitope region III also showed slight structural modification between isolates. MoAbs against regions II or III were relatively ineffective in suppressing gametocyte infectivity compared to MoAbs against region I. However, certain combinations of MoAbs against regions II and III together acted synergistically to suppress infectivity to mosquitoes. All these epitopes failed to react with MoAb when the antigen was presented in reduced form. A fourth epitope, however, was identified which reacted strongly with MoAb when the antigen was presented in reduced form. The MoAb against this epitope had no effect on the infectivity of gametocytes of P. falciparum to mosquitoes.

Background Vaccines against all stages of the malaria parasite are in development, mainly for Plasmodium falciparum, which causes the most serious form of malaria. Pre-erythrocytic vaccines act to prevent or delay a malaria attack by attacking the sporozoite and liver stages before the parasite reaches the bloodstream. Objectives To assess the efficacy and safety of pre-erythrocytic malaria vaccines against any type of human malaria. Search methods In March 2006, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2006, Issue 1), MEDLINE, EMBASE, LILACS, and the Science Citation Index. We also searched conference proceedings and reference lists of articles, and contacted organizations and researchers in the field. Selection criteria Randomized controlled trials comparing pre-erythrocytic vaccines with placebo, control vaccine, or routine antimalarial control measures in people of any age receiving an artificial challenge or natural exposure to malaria infection. Data collection and analysis Both authors independently assessed trial quality and extracted data. Results of meta-analyses were expressed as risk ratios with 95% confidence intervals (CI) using an intention-to-treat analysis. Main results Nine safety and efficacy trials, and two safety trials, with over 3000 participants were included. In semi-immune children, RTS,S vaccine reduced clinical episodes of malaria by 26% (95% CI 13% to 37%) and severe malaria by 58% (95% CI 15% to 79%) for up to 18 months. Prevalence of parasitaemia was also reduced by 26% (95% CI 11% to 38%) at six months after immunization. RTS,S also reduced clinical malaria episodes by 63% (95% CI 18% to 83%) in semi-immune adult men in the second year of follow up after a booster dose. No severe adverse events were judged to be related to RTS,S vaccine, although the frequencies of injection site pain, swelling, arm motion limitation, headache, and malaise were increased in the vaccine groups. There was no evidence for effect of the CS-NANP vaccines (307 participants, 3 trials), CS102 peptide vaccine (14 participants, 1 trial), or the ME-TRAP vaccine (372 participants, 1 trial). Authors' conclusions RTS,S vaccine was effective in preventing a significant number of clinical malaria episodes, including good protection against severe malaria in children for 18 months. No severe adverse events were attributable to the vaccine. Progression of this vaccine towards licensing is justified while efforts to increase its efficacy continue. The other vaccines do not look promising and further research is a priority.

Background A malaria vaccine is badly needed. SPf66 was one of the earliest vaccines developed. It is a synthetic peptide vaccine containing antigens from the blood stages of malaria linked together with an antigen from the sporozoite stage, and is targeted mainly against the blood (asexual) stages. Objectives To assess the effect of SPf66 malaria vaccines against Plasmodium falciparum, P. vivax, P. malariae, and P. ovale in preventing infection, disease, and death. Search strategy We searched the Cochrane Infectious Diseases Group Specialized Register (September 2005), CENTRAL (The Cochrane Library 2005, Issue 3), MEDLINE (1966 to September 2005), EMBASE (1980 to September 2005), LILACS (1982 to September 2005), Science Citation Index (1981 to September 2005), and reference lists of articles. We also contacted organizations and researchers in the field. Selection criteria Randomized and quasi-randomized controlled trials comparing SPf66 vaccine with placebo or routine antimalarial control measures in people of any age receiving an artificial challenge or natural exposure to malaria infection (any species). Data collection and analysis Two people independently assessed trial quality and extracted data, including adverse events. Results were expressed as relative risks (RR) with 95% confidence intervals (CI). Main results Ten efficacy trials of SPf66 involving 9698 participants were included. Results with SPf66 in reducing new episodes of P. falciparum malaria were heterogeneous: it was not effective in four African trials (RR 0.98, 95% CI 0.90 to 1.07; 2371 participants) or in one Asian trial (RR 1.06, 95% CI 0.90 to 1.25; 1221 participants). In four trials in South America the number of first attacks with P. falciparum was reduced by 28% (RR 0.72, 95% CI 0.63 to 0.82; 3807 participants). It did not reduce episodes of P. vivax malaria or admission to hospital with severe malaria. Trials have not indicated any serious adverse events with SPf66 vaccine. Authors' conclusions There is no evidence for protection by SPf66 vaccines against P. falciparum in Africa. There is a modest reduction in attacks of P. falciparum malaria following vaccination with SPf66 in South America. There is no justification for further trials of SPf66 in its current formulation. Further research with SPf66 vaccines in South America or with new formulations of SPf66 may be justified.

Summary Sera from individuals living in malaria endemic areas of Papua New Guinea were tested for their effect on inactivity of Plasmodium falciparum gametocyles grown in culture to Anopheles freeborni mosquitoes. Consistent reduction of infectivity to less than 5% of control was observed with nine out of the 41 sera from the endemic area tested and also with three out of seven sera tested from individuals rarely exposed to malaria infection. Gamete surface antigens recognized by the sera were investigated by immunoprecipitation from 125I surface-labelled gametes extracted in SDS and Triton X-100. The main antigens recognized were of the same mol. wt (230, 48 and 45 kD) as those known to be targets of transmission-blocking monoclonal antibodies. A significant negative correlation was observed between the total ct/min immunoprecipitated from surface-labelled gametes by the sera and the average number of oocysts per gut observed in membrane feeding experiments with these sera. Spearmann's rank correlation coefficient indicated that suppression of infectivily correlated strongly with the presence of antibodies against the 230 kD protein; there was no significant correlation between suppression and antibodies to the 48/45 kD proteins. The antibody response to the different gamete surface antigens varied greatly in sera from the endemic areas suggesting that individuals respond differently to each gamete antigen.

Evidence is presented that female Anopheles farauti Laveran released in an alien village dispersed more, in their first oviposition cycle after release, than females released in their village of capture. In a subsidiary experiment transporting the mosquitoes did not affect dispersal; wind speed or direction was not sufficient to account for the phenomenon. It is hypothesized that these permanent-pool breeding mosquitoes make appetitive long-range flights to oviposition sites. Mosquitoes blood-fed before midnight had a shorter oviposition cycle than those fed just before dawn. Nulliparous females, and those with well-defined ovariolar dilatations, predominated in the early evening whereas females that had oviposited recently were largely collected in the middle and later parts of the night.