The epidemiological transition in Papua New Guinea: new evidence from verbal autopsy studies.

BACKGROUND: Recent economic growth in Papua New Guinea (PNG) would suggest that the country may be experiencing an epidemiological transition, characterized by a reduction in infectious diseases and a growing burden from non-communicable diseases (NCDs). However, data on cause-specific mortality in PNG are very sparse, and the extent of the transition within the country is poorly understood. METHODS: Mortality surveillance was established in four small populations across PNG: West Hiri in Central Province, Asaro Valley in Eastern Highlands Province, Hides in Hela Province and Karkar Island in Madang Province. Verbal autopsies (VAs) were conducted on all deaths identified, and causes of death were assigned by SmartVA and classified into five broad disease categories: endemic NCDs; emerging NCDs; endemic infections; emerging infections; and injuries. Results from previous PNG VA studies, using different VA methods and spanning the years 1970 to 2001, are also presented here. RESULTS: A total of 868 deaths among adolescents and adults were identified and assigned a cause of death. NCDs made up the majority of all deaths (40.4%), with the endemic NCD of chronic respiratory disease responsible for the largest proportion of deaths (10.5%), followed by the emerging NCD of diabetes (6.2%). Emerging infectious diseases outnumbered endemic infectious diseases (11.9% versus 9.5%). The distribution of causes of death differed across the four sites, with emerging NCDs and emerging infections highest at the site that is most socioeconomically developed, West Hiri. Comparing the 1970-2001 VA series with the present study suggests a large decrease in endemic infections. CONCLUSIONS: Our results indicate immediate priorities for health service planning and for strengthening of vital registration systems, to more usefully serve the needs of health priority setting.

Comparative efficacy of low-dose versus standard-dose azithromycin for patients with yaws: a randomised non-inferiority trial in Ghana and Papua New Guinea.

BACKGROUND: A dose of 30 mg/kg of azithromycin is recommended for treatment of yaws, a disease targeted for global eradication. Treatment with 20 mg/kg of azithromycin is recommended for the elimination of trachoma as a public health problem. In some settings, these diseases are co-endemic. We aimed to determine the efficacy of 20 mg/kg of azithromycin compared with 30 mg/kg azithromycin for the treatment of active and latent yaws. METHODS: We did a non-inferiority, open-label, randomised controlled trial in children aged 6-15 years who were recruited from schools in Ghana and schools and the community in Papua New Guinea. Participants were enrolled based on the presence of a clinical lesion that was consistent with infectious primary or secondary yaws and a positive rapid diagnostic test for treponemal and non-treponemal antibodies. Participants were randomly assigned (1:1) to receive either standard-dose (30 mg/kg) or low-dose (20 mg/kg) azithromycin by a computer-generated random number sequence. Health-care workers assessing clinical outcomes in the field were not blinded to the patient's treatment, but investigators involved in statistical or laboratory analyses and the participants were blinded to treatment group. We followed up participants at 4 weeks and 6 months. The primary outcome was cure at 6 months, defined as lesion healing at 4 weeks in patients with active yaws and at least a four-fold decrease in rapid plasma reagin titre from baseline to 6 months in patients with active and latent yaws. Active yaws was defined as a skin lesion that was positive for Treponema pallidum ssp pertenue in PCR testing. We used a non-inferiority margin of 10%. This trial was registered with ClinicalTrials.gov, number NCT02344628. FINDINGS: Between June 12, 2015, and July 2, 2016, 583 (65·1%) of 895 children screened were enrolled; 292 patients were assigned a low dose of azithromycin and 291 patients were assigned a standard dose of azithromycin. 191 participants had active yaws and 392 had presumed latent yaws. Complete follow-up to 6 months was available for 157 (82·2%) of 191 patients with active yaws. In cases of active yaws, cure was achieved in 61 (80·3%) of 76 patients in the low-dose group and in 68 (84·0%) of 81 patients in the standard-dose group (difference 3·7%; 95% CI -8·4 to 15·7%; this result did not meet the non-inferiority criterion). There were no serious adverse events reported in response to treatment in either group. The most commonly reported adverse event at 4 weeks was gastrointestinal upset, with eight (2·7%) participants in each group reporting this symptom. INTERPRETATION: In this study, low-dose azithromycin did not meet the prespecified non-inferiority margin compared with standard-dose azithromycin in achieving clinical and serological cure in PCR-confirmed active yaws. Only a single participant (with presumed latent yaws) had definitive serological failure. This work suggests that 20 mg/kg of azithromycin is probably effective against yaws, but further data are needed. FUNDING: Coalition for Operational Research on Neglected Tropical Diseases.

Risk factors and pregnancy outcomes associated with placental malaria in a prospective cohort of Papua New Guinean women.

BACKGROUND: Plasmodium falciparum in pregnancy results in substantial poor health outcomes for both mother and child, particularly in young, primigravid mothers who are at greatest risk of placental malaria (PM) infection. Complications of PM include maternal anaemia, low birth weight and preterm delivery, which contribute to maternal and infant morbidity and mortality in coastal Papua New Guinea (PNG). METHODS: Placental biopsies were examined from 1451 pregnant women who were enrolled in a malaria prevention study at 14-26 weeks gestation. Clinical and demographic information were collected at first antenatal clinic visits and women were followed until delivery. Placental biopsies were collected and examined for PM using histology. The presence of infected erythrocytes and/or the malaria pigment in monocytes or fibrin was used to determine the type of placental infection. RESULTS: Of 1451 placentas examined, PM infection was detected in 269 (18.5%), of which 54 (3.7%) were acute, 55 (3.8%) chronic, and 160 (11.0%) were past infections. Risk factors for PM included residing in rural areas (adjusted odds ratio (AOR) 3.65, 95% CI 1.76-7.51; p ≤ 0.001), being primigravid (AOR 2.45, 95% CI 1.26-4.77; p = 0.008) and having symptomatic malaria during pregnancy (AOR 2.05, 95% CI 1.16-3.62; p = 0.013). After adjustment for covariates, compared to uninfected women, acute infections (AOR 1.97, 95% CI 0.98-3.95; p = 0.056) were associated with low birth weight babies, whereas chronic infections were associated with preterm delivery (AOR 3.92, 95% CI 1.64-9.38; p = 0.002) and anaemia (AOR 2.22, 95% CI 1.02-4.84; p = 0.045). CONCLUSIONS: Among pregnant PNG women receiving at least one dose of intermittent preventive treatment in pregnancy and using insecticide-treated bed nets, active PM infections were associated with adverse outcomes. Improved malaria prevention is required to optimize pregnancy outcomes.

Effects of Plasmodium falciparum infection on umbilical artery resistance and intrafetal blood flow distribution: a Doppler ultrasound study from Papua New Guinea.

BACKGROUND: Doppler velocimetry studies of umbilical artery (UA) and middle cerebral artery (MCA) flow help to determine the presence and severity of fetal growth restriction. Increased UA resistance and reduced MCA pulsatility may indicate increased placental resistance and intrafetal blood flow redistribution. Malaria causes low birth weight and fetal growth restriction, but few studies have assessed its effects on uteroplacental and fetoplacental blood flow. METHODS: Colour-pulsed Doppler ultrasound was used to assess UA and MCA flow in 396 Papua New Guinean singleton fetuses. Abnormal flow was defined as an UA resistance index above the 90th centile, and/or a MCA pulsatility index and cerebroplacental ratio (ratio of MCA and UA pulsatility index) below the 10th centile of population-specific models fitted to the data. Associations between malaria (peripheral infection prior to and at ultrasound examination, and any gestational infection, i.e., 'exposure') and abnormal flow, and between abnormal flow and birth outcomes, were estimated. RESULTS: Of 78 malaria infection episodes detected before or at the ultrasound visit, 62 (79.5%) were Plasmodium falciparum (34 sub-microscopic infections), and 16 were Plasmodium vivax. Plasmodium falciparum infection before or at Doppler measurement was associated with increased UA resistance (adjusted odds ratio (aOR) 2.3 95% CI 1.0-5.2, P = 0.047). When assessed by 'exposure', P. falciparum infection was significantly associated with increased UA resistance (all infections: 2.4, 1.1-4.9, P = 0.024; sub-microscopic infections 2.6, 1.0-6.6, P = 0.051) and a reduced MCA pulsatility index (all infections: 2.6, 1.2-5.3, P = 0.012; sub-microscopic infections: 2.8, 1.1-7.5, P = 0.035). Sub-microscopic P. falciparum infections were additionally associated with a reduced cerebroplacental ratio (3.64, 1.22-10.88, P = 0.021). There were too few P. vivax infections to draw robust conclusions. An increased UA resistance index was associated with histological evidence of placental malaria (5.1, 2.3-10.9, P < 0.001; sensitivity 0.26, specificity 0.93). A low cerebroplacental Doppler ratio was associated with concurrently measuring small-for-gestational-age, and with low birth weight. DISCUSSION/CONCLUSION: Both microscopic and sub-microscopic P. falciparum infections impair fetoplacental and intrafetal flow, at least temporarily. Increased UA resistance has high specificity but low sensitivity for the detection of placental infection. These findings suggest that interventions to protect the fetus should clear and prevent both microscopic and sub-microscopic malarial infections. Trial Registration ClinicalTrials.gov NCT01136850. Registered 06 April 2010.

Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women.

P. vivax infection during pregnancy has been associated with poor outcomes such as anemia, low birth weight and congenital malaria, thus representing an important global health problem. However, no vaccine is currently available for its prevention. Vir genes were the first putative virulent factors associated with P. vivax infections, yet very few studies have examined their potential role as targets of immunity. We investigated the immunogenic properties of five VIR proteins and two long synthetic peptides containing conserved VIR sequences (PvLP1 and PvLP2) in the context of the PregVax cohort study including women from five malaria endemic countries: Brazil, Colombia, Guatemala, India and Papua New Guinea (PNG) at different timepoints during and after pregnancy. Antibody responses against all antigens were detected in all populations, with PNG women presenting the highest levels overall. P. vivax infection at sample collection time was positively associated with antibody levels against PvLP1 (fold-increase: 1.60 at recruitment -first antenatal visit-) and PvLP2 (fold-increase: 1.63 at delivery), and P. falciparum co-infection was found to increase those responses (for PvLP1 at recruitment, fold-increase: 2.25). Levels of IgG against two VIR proteins at delivery were associated with higher birth weight (27 g increase per duplicating antibody levels, p<0.05). Peripheral blood mononuclear cells from PNG uninfected pregnant women had significantly higher antigen-specific IFN-γ TH1 responses (p=0.006) and secreted less pro-inflammatory cytokines TNF and IL-6 after PvLP2 stimulation than P. vivax-infected women (p<0.05). These data demonstrate that VIR antigens induce the natural acquisition of antibody and T cell memory responses that might be important in immunity to P. vivax during pregnancy in very diverse geographical settings.

Metaanalysis of the Performance of a Combined Treponemal and Nontreponemal Rapid Diagnostic Test for Syphilis and Yaws.

BACKGROUND: The human treponematoses are important causes of disease. Mother-to-child transmission of syphilis remains a major cause of stillbirth and neonatal death. There are also almost 100 000 cases of endemic treponemal disease reported annually, predominantly yaws. Rapid diagnostic tests (RDTs) would improve access to screening for these diseases. Most RDTs cannot distinguish current and previous infection. The Dual Path Platform (DPP) Syphilis Screen & Confirm test includes both a treponemal (T1) and nontreponemal (T2) component and may improve the accuracy of diagnosis. METHODS: We conducted a metaanalysis of published and unpublished evaluations of the DPP-RDT for the diagnosis of syphilis and yaws. We calculated the sensitivity, specificity, and overall agreement of the test compared with reference laboratory tests. RESULTS: Nine evaluations, including 7267 tests, were included. Sensitivity was higher in patients with higher titer rapid plasma reagin (≥1:16) for both the T1 (98.2% vs 90.1%, P < .0001) and the T2 component (98.2% vs 80.6%, P < .0001). Overall agreement between the DPP test and reference serology was 85.2% (84.4%-86.1%). Agreement was highest for high-titer active infection and lowest for past infection. CONCLUSIONS: The RDT has good sensitivity and specificity of the treponemal and nontreponemal components both in cases of suspected syphilis and yaws, although the sensitivity is decreased at lower antibody titers.

Azithromycin-containing intermittent preventive treatment in pregnancy affects gestational weight gain, an important predictor of birthweight in Papua New Guinea - an exploratory analysis.

In Papua New Guinea, intermittent preventive treatment with sulphadoxine-pyrimethamine and azithromycin (SPAZ-IPTp) increased birthweight despite limited impact on malaria and sexually transmitted infections. To explore possible nutrition-related mechanisms, we evaluated associations between gestational weight gain (GWG), enrolment body mass index (BMI) and mid-upper arm circumference (MUAC), and birthweight. We investigated whether the increase in birthweight associated with SPAZ-IPTp may partly be driven by a treatment effect on GWG. The mean GWG rate was 393 g/week (SD 250; n = 948). A 100 g/week increase in GWG was associated with a 14 g (95% CI 2.6, 25.4) increase in birthweight (P = 0.016). Enrolment BMI and MUAC also positively correlated with birthweight. SPAZ-IPTp was associated with increased GWG [58 g/week (26, 900), P < 0.001, n = 948] and with increased birthweight [48 g, 95% CI (8, 880), P = 0.019] when all eligible women were considered (n = 1947). Inclusion of GWG reduced the birthweight coefficient associated with SPAZ-IPTp by 18% from 44 to 36 g (n = 948), although SPAZ-IPTp was not significantly associated with birthweight among women for whom GWG data were available (P = 0.13, n = 948). One month post-partum, fewer women who had received SPAZ-IPTp had a low post-partum BMI (<18.5 kg m(-2) ) [adjusted risk ratio: 0.55 (95% CI 0.36, 0.82), P = 0.004] and their babies had a reduced risk of wasting [risk ratio 0.39 (95% CI 0.21, 0.72), P = 0.003]. SPAZ-IPTp increased GWG, which could explain its impact on birthweight and maternal post-partum BMI. Future trials of SPAZ-IPTp must incorporate detailed anthropometric evaluations to investigate mechanisms of effects on maternal and child health.

Accuracy of an HRP-2/panLDH rapid diagnostic test to detect peripheral and placental Plasmodium falciparum infection in Papua New Guinean women with anaemia or suspected malaria.

BACKGROUND: The diagnosis of malaria during pregnancy is complicated by placental sequestration, asymptomatic infection, and low-density peripheral parasitaemia. Where intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine is threatened by drug resistance, or is inappropriate due to low transmission, intermittent screening and treatment (ISTp) with rapid diagnostic tests for malaria (RDT) could be a valuable alternative. Therefore, the accuracy of RDTs to detect peripheral and placental infection was assessed in a declining transmission setting in Papua New Guinea (PNG). METHODS: The performance of a combination RDT detecting histidine-rich protein-2 (HRP-2) and Plasmodium lactate dehydrogenase (pLDH), and light microscopy (LM), to diagnose peripheral Plasmodium falciparum and Plasmodium vivax infections during pregnancy, were assessed using quantitative real-time PCR (qPCR) as the reference standard. Participants in a malaria prevention trial in PNG with a haemoglobin ≤90 g/L, or symptoms suggestive of malaria, were tested. Ability of RDT and LM to detect active placental infection on histology was evaluated in some participants. RESULTS: Among 876 women, 1162 RDTs were undertaken (anaemia: 854 [73.5 %], suspected malaria: 308 [26.5 %]). qPCR detected peripheral infection during 190 RDT episodes (165 P. falciparum, 19 P. vivax, 6 mixed infections). Overall, RDT detected peripheral P. falciparum infection with 45.6 % sensitivity (95 % CI 38.0-53.4), a specificity of 96.4 % (95.0-97.4), a positive predictive value of 68.4 % (59.1-76.8), and a negative predictive value of 91.1 % (89.2-92.8). RDT performance to detect P. falciparum was inferior to LM, more so amongst anaemic women (18.6 vs 45.3 % sensitivity, Liddell's exact test, P < 0.001) compared to symptomatic women (72.9 vs 82.4 % sensitivity, P = 0.077). RDT and LM missed 88.0 % (22/25) and 76.0 % (19/25) of P. vivax infections, respectively. In a subset of women tested at delivery and who had placental histology (n = 158) active placental infection was present in 19.6 %: all three peripheral blood infection detection methods (RDT, LM, qPCR) missed >50 % of these infections. CONCLUSIONS: In PNG, HRP-2/pLDH RDTs may be useful to diagnose peripheral P. falciparum infections in symptomatic pregnant women. However, they are not sufficiently sensitive for use in intermittent screening amongst asymptomatic (anaemic) women. These findings have implications for the management of malaria in pregnancy. The adverse impact of infections undetected by RDT or LM on pregnancy outcomes needs further evaluation.

Determining effects of areca (betel) nut chewing in a prospective cohort of pregnant women in Madang Province, Papua New Guinea.

BACKGROUND: Chewing areca nut (AN), also known as betel nut, is common in Asia and the South Pacific and the habit has been linked to a number of serious health problems including oral cancer. Use of AN in pregnancy has been associated with a reduction in mean birthweight in some studies, but this association and the relationship between AN chewing and other adverse pregnancy outcomes remain poorly understood. METHODS: We assessed the impact of AN chewing on adverse outcomes including stillbirth, low birthweight (LBW, <2,500 g) and anaemia at delivery (haemoglobin <11.0 g/dL) in a longitudinal cohort of 2,700 pregnant women residing in rural lowland Papua New Guinea (PNG) from November 2009 until February 2013. Chewing habits and participant characteristics were evaluated at first antenatal visit and women were followed until delivery. RESULTS: 83.3% [2249/2700] of pregnant women used AN, and most chewed on a daily basis (86.2% [1939/2249]. Smoking and alcohol use was reported by 18.9% (511/2700) and 5.0% (135/2688) of women, respectively. AN use was not associated with pregnancy loss or congenital abnormalities amongst women with a known pregnancy outcome (n = 2215). Analysis of 1769 birthweights did not demonstrate an association between AN and LBW (chewers: 13.7% [200/1459] vs. non-chewers: 14.5% [45/310], P = 0.87) or reduced mean birthweight (2957 g vs. 2966 g; P = 0.76). Women using AN were more likely to be anaemic (haemoglobin <11 g/dL) at delivery (75.2% [998/1314] vs. 63.9% [182/285], adjusted odds ratio [95% CI]: 1.67 [1.27, 2.20], P < 0.001). Chewers more commonly had male babies than non-chewers (46.1% [670/1455] vs. 39.8% [123/309], P = 0.045). CONCLUSIONS: AN chewing may contribute to anaemia. Although not associated with other adverse pregnancy outcome in this cohort gestational AN use should be discouraged, given the potential adverse effects on haemoglobin and well-established long-term health risk including oral cancer. Future research evaluating the potential association of AN use and anaemia may be warranted. TRIAL REGISTRATION: ClinicalTrials.gov NCT01136850 (06 April 2010).

Preterm or not--an evaluation of estimates of gestational age in a cohort of women from Rural Papua New Guinea.

BACKGROUND: Knowledge of accurate gestational age is required for comprehensive pregnancy care and is an essential component of research evaluating causes of preterm birth. In industrialised countries gestational age is determined with the help of fetal biometry in early pregnancy. Lack of ultrasound and late presentation to antenatal clinic limits this practice in low-resource settings. Instead, clinical estimators of gestational age are used, but their accuracy remains a matter of debate. METHODS: In a cohort of 688 singleton pregnancies from rural Papua New Guinea, delivery gestational age was calculated from Ballard score, last menstrual period, symphysis-pubis fundal height at first visit and quickening as well as mid- and late pregnancy fetal biometry. Published models using sequential fundal height measurements and corrected last menstrual period to estimate gestational age were also tested. Novel linear models that combined clinical measurements for gestational age estimation were developed. Predictions were compared with the reference early pregnancy ultrasound (<25 gestational weeks) using correlation, regression and Bland-Altman analyses and ranked for their capability to predict preterm birth using the harmonic mean of recall and precision (F-measure). RESULTS: Average bias between reference ultrasound and clinical methods ranged from 0-11 days (95% confidence levels: 14-42 days). Preterm birth was best predicted by mid-pregnancy ultrasound (F-measure: 0.72), and neuromuscular Ballard score provided the least reliable preterm birth prediction (F-measure: 0.17). The best clinical methods to predict gestational age and preterm birth were last menstrual period and fundal height (F-measures 0.35). A linear model combining both measures improved prediction of preterm birth (F-measure: 0.58). CONCLUSIONS: Estimation of gestational age without ultrasound is prone to significant error. In the absence of ultrasound facilities, last menstrual period and fundal height are among the more reliable clinical measures. This study underlines the importance of strengthening ultrasound facilities and developing novel ways to estimate gestational age.

Factors associated with ultrasound-aided detection of suboptimal fetal growth in a malaria-endemic area in Papua New Guinea.

BACKGROUND: Fetal growth restriction (FGR) is associated with increased infant mortality rates and ill-health in adulthood. Evaluation of fetal growth requires ultrasound. As a result, ultrasound-assisted evaluations of causes of FGR in malaria-endemic developing countries are rare. We aimed to determine factors associated with indicators of abnormal fetal growth in rural lowland Papua New Guinea (PNG). METHODS: Weights and growth of 671 ultrasound-dated singleton pregnancies (<25 gestational weeks) were prospectively monitored using estimated fetal weights and birthweights. Maternal nutritional status and haemoglobin levels were assessed at enrolment, and participants were screened for malaria on several occasions. FGR was suspected upon detection of an estimated fetal weight or birthweight <10(th) centile (small-for-gestational age) and/or low fetal weight gain, defined as a change in weight z-score in the first quartile. Factors associated with fetal weight and fetal weight gain were additionally assessed by evaluating differences in weight z-scores and change in weight z-scores. Log-binomial and linear mixed effect models were used to determine factors associated with indicators of FGR. RESULTS: SGA and low weight gain were detected in 48.3% and 37.0% of pregnancies, respectively. Of participants, 13.8%, 21.2%, and 22.8% had a low mid-upper arm circumference (MUAC, <22 cms), short stature (<150 cms) and anaemia (haemoglobin <90 g/L) at first antenatal visit. 24.0% (161/671) of women had at least one malaria infection detected in peripheral blood. A low MUAC (adjusted risk ratio [aRR] 1.51, 95% CI 1.29, 1.76, P < 0.001), short stature (aRR 1.27, 95% CI 1.04, 1.55, P = 0.009), and anaemia (aRR 1.27, 95% CI 1.06, 1.51, P = 0.009) were associated with SGA, and a low body mass index was associated with low fetal weight gain (aRR 2.10, 95% CI 1.62, 2.71, P < 0.001). Additionally, recent receipt of intermittent preventive treatment in pregnancy was associated with increased weight z-scores, and anaemia with reduced change in weight z-scores. Malaria infection was associated with SGA on crude but not adjusted analyses (aRR 1.13, 95% CI 0.95, 1.34, P = 0.172). CONCLUSION: Macronutrient undernutrition and anaemia increased the risk of FGR. Antenatal nutritional interventions and malaria prevention could improve fetal growth in PNG.

Proinflammatory responses and higher IL-10 production by T cells correlate with protection against malaria during pregnancy and delivery outcomes.

Pregnancy triggers immunological changes aimed to tolerate the fetus. However, it has not been properly addressed whether similar changes occur in tropical areas with high infection pressure and whether these changes render women more susceptible to infectious diseases. We compared the frequencies of T cell subsets, including regulatory T cells, in pregnant and nonpregnant women from Papua New Guinea, a high malaria transmission area, and from Spain, a malaria-free country. We also assessed the relationship among these cellular subsets, malaria infection, and delivery outcomes. CD4(+)FOXP3(+)CD127(low) T cells (Tregs) were decreased in pregnant women in both countries but were not associated with malaria infection or poor delivery outcomes. An expansion of IFN-γ-producing cells and intracytoplasmic IFN-γ levels was found in pregnant compared with nonpregnant women only in Papua New Guinea. Increased CD4(+)IL-10(+)IFN-γ(+) frequencies and Treg-IFN-γ production were found in women with current Plasmodium falciparum infection. Higher CD4(+)IL-10(-)IFN-γ(+) T cells frequencies and production of proinflammatory cytokines (including TNF and IL-2) at recruitment (first antenatal visit) had a protective association with birth weight and future (delivery) P. falciparum infection, respectively. Higher intracellular IL-10 levels in T cells had a protective association with future P. falciparum infection and hemoglobin levels at delivery. The protective associations were found also with nonmalaria-specific T cell responses. Treg frequencies positively correlated with plasma eotaxin concentrations, but this subset did not express eotaxin receptor CCR3. Thus, an activated immune system during pregnancy might contribute to protection against malaria during pregnancy and poor delivery outcomes.

Impact of intermittent preventive treatment in pregnancy with azithromycin-containing regimens on maternal nasopharyngeal carriage and antibiotic sensitivity of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus: a cross-sectional survey at delivery.

Sulfadoxine-pyrimethamine (SP) plus azithromycin (AZ) (SPAZ) has the potential for intermittent preventive treatment of malaria in pregnancy (IPTp), but its use could increase circulation of antibiotic-resistant bacteria associated with severe pediatric infections. We evaluated the effect of monthly SPAZ-IPTp compared to a single course of SP plus chloroquine (SPCQ) on maternal nasopharyngeal carriage and antibiotic susceptibility of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus at delivery among 854 women participating in a randomized controlled trial in Papua New Guinea. Serotyping was performed, and antibiotic susceptibility was evaluated by disk diffusion and Etest. Potential risk factors for carriage were examined. Nasopharyngeal carriage at delivery of S. pneumoniae (SPAZ, 7.2% [30/418], versus SPCQ, 19.3% [84/436]; P<0.001) and H. influenzae (2.9% [12/418] versus 6.0% [26/436], P=0.028), but not S. aureus, was significantly reduced among women who had received SPAZ-IPTp. The number of macrolide-resistant pneumococcal isolates was small but increased in the SPAZ group (13.3% [4/30], versus SPCQ, 2.2% [2/91]; P=0.033). The proportions of isolates with serotypes covered by the 13-valent pneumococcal conjugate vaccine were similar (SPAZ, 10.3% [3/29], versus SPCQ, 17.6% [16/91]; P=0.352). Although macrolide-resistant isolates were rare, they were more commonly detected in women who had received SPAZ-IPTp, despite the significant reduction of maternal carriage of S. pneumoniae and H. influenzae observed in this group. Future studies on SPAZ-IPTp should evaluate carriage and persistence of macrolide-resistant S. pneumoniae and other pathogenic bacteria in both mothers and infants and assess the clinical significance of their circulation.

Sulphadoxine-pyrimethamine plus azithromycin for the prevention of low birthweight in Papua New Guinea: a randomised controlled trial.

BACKGROUND: Intermittent preventive treatment in pregnancy has not been evaluated outside of Africa. Low birthweight (LBW, <2,500 g) is common in Papua New Guinea (PNG) and contributing factors include malaria and reproductive tract infections. METHODS: From November 2009 to February 2013, we conducted a parallel group, randomised controlled trial in pregnant women (≤ 26 gestational weeks) in PNG. Sulphadoxine-pyrimethamine (1,500/75 mg) plus azithromycin (1 g twice daily for 2 days) (SPAZ) monthly from second trimester (intervention) was compared against sulphadoxine-pyrimethamine and chloroquine (450 to 600 mg, daily for three days) (SPCQ) given once, followed by SPCQ placebo (control). Women were assigned to treatment (1:1) using a randomisation sequence with block sizes of 32. Participants were blinded to assignments. The primary outcome was LBW. Analysis was by intention-to-treat. RESULTS: Of 2,793 women randomised, 2,021 (72.4%) were included in the primary outcome analysis (SPCQ: 1,008; SPAZ: 1,013). The prevalence of LBW was 15.1% (305/2,021). SPAZ reduced LBW (risk ratio [RR]: 0.74, 95% CI: 0.60-0.91, P = 0.005; absolute risk reduction (ARR): 4.5%, 95% CI: 1.4-7.6; number needed to treat: 22), and preterm delivery (0.62, 95% CI: 0.43-0.89, P = 0.010), and increased mean birthweight (41.9 g, 95% CI: 0.2-83.6, P = 0.049). SPAZ reduced maternal parasitaemia (RR: 0.57, 95% CI: 0.35-0.95, P = 0.029) and active placental malaria (0.68, 95% CI: 0.47-0.98, P = 0.037), and reduced carriage of gonorrhoea (0.66, 95% CI: 0.44-0.99, P = 0.041) at second visit. There were no treatment-related serious adverse events (SAEs), and the number of SAEs (intervention 13.1% [181/1,378], control 12.7% [174/1,374], P = 0.712) and AEs (intervention 10.5% [144/1,378], control 10.8% [149/1,374], P = 0.737) was similar. A major limitation of the study was the high loss to follow-up for birthweight. CONCLUSIONS: SPAZ was efficacious and safe in reducing LBW, possibly acting through multiple mechanisms including the effect on malaria and on sexually transmitted infections. The efficacy of SPAZ in the presence of resistant parasites and the contribution of AZ to bacterial antibiotic resistance require further study. The ability of SPAZ to improve pregnancy outcomes warrants further evaluation. TRIAL REGISTRATION: ClinicalTrials.gov NCT01136850 (06 April 2010).

Fetal size in a rural melanesian population with minimal risk factors for growth restriction: an observational ultrasound study from Papua New Guinea.

We conducted a prospective longitudinal study of fetal size in rural Papua New Guinea (PNG) involving 439 ultrasound-dated singleton pregnancies with no obvious risk factors for growth restriction. Sonographically estimated fetal weights (EFWs; N = 788) and birth weights (N = 376) were included in a second-order polynomial regression model (optimal fit) to generate fetal weight centiles. Means for specific fetal biometric measurements were also estimated. Fetal weight centiles from a healthy PNG cohort were consistently lower than those derived from Caucasian and Congolese populations, which overestimated the proportion of fetuses measuring small for gestational age (SGA; < 10th centile). Tanzanian and global reference centiles (Caucasian weight reference adapted to our PNG cohort) were more similar to those observed in our cohort, but the global reference underestimated SGA. Individual biometric measurements did not differ significantly from other cohorts. In rural PNG, a locally derived nomogram may be most appropriate for detection of SGA fetuses.

Sensitivity and specificity of a rapid point-of-care test for active yaws: a comparative study.

BACKGROUND: To eradicate yaws, national control programmes use the Morges strategy (initial mass treatment and biannual resurveys). The resurvey component is designed to actively detect and treat remaining yaws cases and is initiated on the basis of laboratory-supported reactive non-treponemal serology (using the rapid plasma reagin [RPR] test). Unfortunately, the RPR test is available rarely in yaws-endemic areas. We sought to assess a new point-of-care assay-the Dual Path Platform (DPP) syphilis assay, which is based on simultaneous detection of antibodies to treponemal and non-treponemal antigens-for guiding use of antibiotics for yaws eradication. A secondary goal was to ascertain at what timepoint the DPP assay line reverted to negative after treatment. METHODS: 703 children (aged 1-18 years) with suspected clinical yaws living in two remote, yaws-endemic villages in Papua New Guinea were enrolled. Clinical suspicion of yaws was established according to a WHO pictorial guide. We obtained blood samples from all patients. We calculated the sensitivity and specificity of the DPP assay for detection of antibodies to treponemal (T1) and non-treponemal (T2) antigens and compared values against those obtained with standard laboratory tests (the Treponema pallidum haemagglutination assay [TPHA] and the RPR test). We followed up a subsample of children with dually positive serology (T1 and T2) to monitor changes in DPP optical density (using an automatic reader) at 3 and 6 months. This trial is registered with ClinicalTrials.gov, number NCT01841203. FINDINGS: Of 703 participants, 389 (55%) were reactive for TPHA, 305 (43%) for the RPR test, and 287 (41%) for both TPHA and the RPR test. The DPP T1 (treponemal) assay had a sensitivity of 88·4% (95% CI 84·8-91·4) and specificity of 95·2% (92·2-97·3). The DPP T2 (non-treponemal) assay had a sensitivity of 87·9% (83·7-91·3) and specificity of 92·5% (89·4-94·9). In subgroup analyses, sensitivities and specificities did not differ according to type of specimen (plasma vs whole blood). For specimens with an RPR titre of 1:8 or greater, the sensitivity of the DPP T2 assay was 94·1% (95% CI 89·9-96·9). Serological cure (including seroreversion or a fourfold reduction in optical density value) was attained at 6 months in 173 (95%) of 182 children with dual-positive serology. INTERPRETATION: The DPP assay is accurate for identification of antibodies to treponemal and non-treponemal antigens in patients with yaws and avoids the need for laboratory support. A change of diagnostic procedure from the currently implemented RPR test to the simpler DPP assay could ease the implementation of yaws eradication activities. FUNDING: Chembio Diagnostic Systems, Newcrest Mining, and the Papua New Guinea National Department of Health.

Pregnancy and malaria exposure are associated with changes in the B cell pool and in plasma eotaxin levels.

Pregnancy triggers immunological changes aimed to tolerate the fetus, but its impact on B lymphocytes is poorly understood. In addition, exposure to the Plasmodium parasite is associated with altered distribution of peripheral memory B cell (MBC) subsets. To study the combined impact of high malaria exposure and pregnancy in B cell subpopulations, we analyzed PBMCs from pregnant and nonpregnant individuals from a malaria-nonendemic country (Spain) and from a high malaria-endemic country (Papua New Guinea). In the malaria-naive cohorts, pregnancy was associated with a significant expansion of all switched (IgD(-)) MBC and a decrease of naive B cells. Malaria-exposed women had more atypical MBC and fewer marginal zone-like MBC, and their levels correlated with both Plasmodium vivax- and Plasmodium falciparum-specific plasma IgG levels. Classical but not atypical MBC were increased in P. falciparum infections. Moreover, active atypical MBC positively correlated with proinflammatory cytokine plasma concentrations and had lower surface IgG levels than the average. Decreased plasma eotaxin (CCL11) levels were associated with pregnancy and malaria exposure and also correlated with B cell subset frequencies. Additionally, active atypical and active classical MBC expressed higher levels of eotaxin receptor CCR3 than the other B cell subsets, suggesting a chemotactic effect of eotaxin on these B cell subsets. These findings are important to understand immunity to infections like malaria that result in negative outcomes for both the mother and the newborn and may have important implications on vaccine development.

A case of ultrasound-guided prenatal diagnosis of prune belly syndrome in Papua New Guinea--implications for management.

BACKGROUND: Prune belly syndrome is a rare congenital malformation of unknown aetiology and is characterised by abnormalities of the urinary tract, a deficiency of abdominal musculature and bilateral cryptorchidism in males. We report a case of prune belly syndrome from Papua New Guinea, which was suspected on pregnancy ultrasound scan and confirmed upon delivery. CASE PRESENTATION: A 26-year-old married woman, Gravida 3 Para 2, presented to antenatal clinic in Madang, Papua New Guinea, at 21(+5) weeks' gestation by dates. She was well with no past medical or family history of note. She gave consent to participate in a clinical trial on prevention of malaria in pregnancy and underwent repeated ultrasound examinations which revealed a live fetus with persistent megacystis and anhydramnios. Both mother and clinicians agreed on conservative management of the congenital abnormality. The mother spontaneously delivered a male fetus weighing 2010 grams at 34 weeks' gestation with grossly abnormal genitalia including cryptorchidism, penile aplasia and an absent urethral meatus, absent abdominal muscles and hypoplastic lungs. The infant passed away two hours after delivery. This report discusses the implications of prenatal detection of severe congenital abnormalities in PNG. CONCLUSION: This first, formally reported, case of prune belly syndrome from a resource-limited setting in the Oceania region highlights the importance of identifying and documenting congenital abnormalities. Women undergoing antenatal ultrasound examinations must be carefully counseled on the purpose and the limitations of the scan. The increasing use of obstetric ultrasound in PNG will inevitably result in a rise in prenatal detection of congenital abnormalities. This will need to be met with adequate training, referral mechanisms and better knowledge of women's attitudes and beliefs on birth defects and ultrasound. National medicolegal guidance regarding induced abortion and resuscitation of a fetus with severe congenital abnormalities may be required.

The impact of tubal ectopic pregnancy in Papua New Guinea--a retrospective case review.

BACKGROUND: Ectopic pregnancy (EP) is an important cause of morbidity and mortality amongst women of reproductive age. Tubal EP is well described in industrialised countries, but less is known about its impact in low-resource countries, in particular in the South Pacific Region. METHODS: We undertook a retrospective review of women with tubal EP treated at a provincial referral hospital in coastal Papua New Guinea over a period of 56 months. Demographic and clinical variables were obtained from patients' medical records and analysed. The institutional rate of tubal EP was calculated, and diagnosis and management reviewed. Potential risk factors for tubal EP were identified, and delays contributing to increased morbidity described. RESULTS: A total of 73 women had tubal EP. The institutional rate of tubal EP over the study period was 6.3 per 1,000 deliveries. There were no maternal deaths due to EP. The mean age of women was 31.5+/-5.7 years, 85% were parous, 67% were rural dwellers and 62% had a history of sub-fertility. The most commonly used diagnostic aid was culdocentesis. One third of women had clinical evidence of shock on arrival. All women with tubal EP were managed by open salpingectomy. Tubal rupture was confirmed for 48% of patients and was more common amongst rural dwellers. Forty-three percent of women had macroscopic evidence of pelvic infection. Two-thirds of patients received blood transfusions, and post-operative recovery lasted six days on average. Late presentation, lack of clinical suspicion, and delays with receiving appropriate treatments were observed. CONCLUSIONS: Tubal EP is a common gynaecological emergency in a referral hospital in coastal PNG, and causes significant morbidity, in particular amongst women residing in rural areas. Sexually transmitted infections are likely to represent the most important risk factor for tubal EP in PNG. Interventions to reduce the morbidity due to tubal EP include the prevention, detection and treatment of sexually transmitted infections, identification and reduction of barriers to prompt presentation, increasing health workers' awareness of ectopic pregnancy, providing pregnancy test kits to rural health centres, and strengthening hospital blood transfusion services, including facilities for autotransfusion.

Does malaria affect placental development? Evidence from in vitro models.

BACKGROUND: Malaria in early pregnancy is difficult to study but has recently been associated with fetal growth restriction (FGR). The pathogenic mechanisms underlying malarial FGR are poorly characterized, but may include impaired placental development. We used in vitro methods that model migration and invasion of placental trophoblast into the uterine wall to investigate whether soluble factors released into maternal blood in malaria infection might impair placental development. Because trophoblast invasion is enhanced by a number of hormones and chemokines, and is inhibited by pro-inflammatory cytokines, many of which are dysregulated in malaria in pregnancy, we further compared concentrations of these factors in blood between malaria-infected and uninfected pregnancies. METHODOLOGY/PRINCIPAL FINDINGS: We measured trophoblast invasion, migration and viability in response to treatment with serum or plasma from two independent cohorts of Papua New Guinean women infected with Plasmodium falciparum or Plasmodium vivax in early pregnancy. Compared to uninfected women, serum and plasma from women with P. falciparum reduced trophoblast invasion (P = .06) and migration (P = .004). P. vivax infection did not alter trophoblast migration (P = .64). The P. falciparum-specific negative effect on placental development was independent of trophoblast viability, but associated with high-density infections. Serum from P. falciparum infected women tended to have lower levels of trophoblast invasion promoting hormones and factors and higher levels of invasion-inhibitory inflammatory factors. CONCLUSION/SIGNIFICANCE: We demonstrate that in vitro models of placental development can be adapted to indirectly study the impact of malaria in early pregnancy. These infections could result in impaired trophoblast invasion with reduced transformation of maternal spiral arteries due to maternal hormonal and inflammatory disturbances, which may contribute to FGR by limiting the delivery of maternal blood to the placenta. Future prevention strategies for malaria in pregnancy should include protection in the first half of pregnancy.