Search

Additional file 5: Figure S5. Heat maps for (A) impact and (B) overtreatment with Primaquine in a real-life scenario after 1, 2 or 3 rounds of PvSeroTAT and under two transmission pressures.

Additional file 4: Figure S4. ROC surfaces for (A) impact and (B) overtreatment with Primaquine administered in a high-efficacy scenario after 1, 2 or 3 rounds of PvSeroTAT and under two transmission pressures.

Additional file 2: Table S2. Public health impact and overtreatment modeled in a moderate transmission setting (qPCR prevalence ~10%). Impact was defined as the reduction in qPCR prevalence observed six months after the last round of intervention; overtreatment corresponded to the administration of a hypnozoiticidal drug to a person whose last blood-stage infection occurred more than 9 months ago. The ���Best-case���, ���High efficacy��� and ���Real-life��� scenario correspond to those described in the main text, with decreasing adherence, efficacy and eligibility.

Additional file 3: Figure S3. Heat maps for (A) impact and (B) overtreatment with an optimal hypnozoiticidal drug as defined by the ���best-case��� scenario and after 1, 2 or 3 rounds of PvSeroTAT and under two transmission pressures.

Additional file 1: Figure S1. Modeled P. vivax qPCR prevalence with various implementations of public health interventions in an endemic situation of moderate transmission. The columns correspond to the different scenarios and rows to the number of intervention rounds, with grey area presenting time of evaluation.

Additional file 1: S1 Text. Supplementary method and results.

Background: The scale-up of effective malaria control in the last decade has resulted in a substantial decline in the incidence of clinical malaria in many countries. The effects on the proportions of asymptomatic and submicroscopic infections, and on transmission potential are yet poorly understood. Methods: In Papua New Guinea, vector control has been intensified since 2008, and improved diagnosis and treatment introduced in 2012. Cross-sectional surveys were conducted in Madang Province in 2006 (n=1280), 2010 (n=2117) and 2014 (n=2516). Infections were quantified by highly sensitive qPCR and gametocytes by RT-qPCR. Results: P. falciparum prevalence by qPCR decreased from 42% in 2006 to 9% in 2014. P. vivax prevalence decreased from 42% in 2006 to 13% in 2010, but then increased to 20% in 2014. Parasite densities decreased 5-fold from 2006 to 2010; 72% of P. falciparum and 87% of P. vivax infections were submicroscopic in 2014. Gametocyte density and positivity correlated closely with parasitemia, and population gametocyte prevalence decreased 3-fold for P. falciparum and 29% for P. vivax from 2010 to 2014. Conclusions: Sustained control has resulted in reduced transmission potential but an increasing proportion of gametocyte carriers are asymptomatic and submicroscopic and represent a challenge to malaria control.

The RTS,S/AS01 malaria vaccine targets the circumsporozoite protein, inducing antibodies associated with the prevention of Plasmodium falciparum infection. We assessed the association between anti-circumsporozoite antibody titres and the magnitude and duration of vaccine effi cacy using data from a phase 3 trial done between 2009 and 2014. Using data from 8922 African children aged 5 1317 months and 6537 African infants aged 6 1312 weeks at first vaccination, we analysed the determinants of immunogenicity after RTS,S/AS01 vaccination with or without a booster dose. We assessed the association between the incidence of clinical malaria and anti-circumsporozoite antibody titres using a model of anti-circumsporozoite antibody dynamics and the natural acquisition of protective immunity over time. RTS,S/AS01-induced anti-circumsporozoite antibody titres were greater in children aged 5 1317 months than in those aged 6 1312 weeks. Pre-vaccination anti-circumsporozoite titres were associated with lower immunogenicity in children aged 6 1312 weeks and higher immunogenicity in those aged 5 1317 months. The immunogenicity of the booster dose was strongly associated with immunogenicity after primary vaccination. Anti-circumsporozoite titres wane according to a biphasic exponential distribution. In participants aged 5 1317 months, the half-life of the shortlived component of the antibody response was 45 days (95% credible interval 42 1348) and that of the long-lived component was 591 days (557 13632). After primary vaccination 12% (11 1313) of the response was estimated to be longlived, rising to 30% (28 1332%) after a booster dose. An anti-circumsporozoite antibody titre of 121 EU/mL (98 13153) was estimated to prevent 50% of infections. Waning anti-circumsporozoite antibody titres predict the duration of effi cacy against clinical malaria across diff erent age categories and transmission intensities, and effi cacy wanes more rapidly at higher transmission intensity Anti-circumsporozoite antibody titres are a surrogate of protection for the magnitude and duration of RTS,S/AS01 effi cacy, with or without a booster dose, providing a valuable surrogate of eff ectiveness for new RTS,S formulations in the age groups considered.

We analyzed data on all laboratory-confirmed cases of H1N1pdm influenza in the UK to 10th June 2009 to estimate epidemiological characteristics. We estimated a mean incubation period of 2.05 days and serial interval of 2.5 days with infectivity peaking close to onset of symptoms. Transmission was initially sporadic but increased from mid-May in England and from early June in Scotland. We estimated 37% of transmission occurred in schools, 24% in households, 28% through travel abroad and the remainder in the wider community. Children under 16 were more susceptible to infection in the household (adjusted OR 5.80, 95% CI 2.99-11.82). Treatment with oseltamivir plus widespread use of prophylaxis significantly reduced transmission (estimated reduction 16%). Households not receiving oseltamivir within 3 days of symptom onset in the index case had significantly increased secondary attack rates (adjusted OR 3.42, 95% CI 1.51-8.55).