Tracing the origins of Plasmodium vivax resurgence after malaria elimination on Aneityum Island in Vanuatu

BACKGROUND

Five years after successful malaria elimination, Aneityum Island in Vanuatu experienced an outbreak of Plasmodium vivax of unknown origin in 2002. Epidemiological investigations revealed several potential sources of P. vivax. We aimed to identify the genetic origin of P. vivax responsible for the resurgence.

METHODS

Five P. vivax microsatellite markers were genotyped using DNA extracted from archived blood samples. A total of 69 samples from four P. vivax populations was included: 29 from the outbreak in 2002, seven from Aneityum in 1999 and 2000, 18 from visitors to Aneityum in 2000, and 15 from nearby Tanna Island in 2002. A neighbour-joining phylogenetic tree was constructed to elucidate the relationships among P. vivax isolates. STRUCTURE and principal component analysis were used to assess patterns of genetic structure.

RESULTS

Here we show distinct genetic origins of P. vivax during the outbreak on Aneityum. While the origin of most P. vivax lineages found during the outbreak remains unidentified, limited genetic diversity among these lineages is consistent with a rapid expansion from a recent common ancestor. Contemporaneous P. vivax from neighboring Tanna and potential relapse of P. vivax acquired from other islands in 1999 and 2000 are also identified as minor contributors to the outbreak.

CONCLUSIONS

Multiple reintroductions of P. vivax after elimination highlight the high receptivity and vulnerability to malaria resurgence in island settings of Vanuatu, despite robust surveillance and high community compliance to control measures.

Evaluation of the protective efficacy of Olyset®Plus ceiling net on reducing malaria prevalence in children in Lake Victoria Basin, Kenya: study protocol for a cluster-randomized controlled trial

BACKGROUND

In the Lake Victoria Basin of western Kenya, malaria remains highly endemic despite high coverage of interventions such as insecticide-impregnated long-lasting insecticidal nets (LLIN). The malaria-protective effect of LLINs is hampered by insecticide resistance in Anopheles vectors and its repurposing by the community. Ceiling nets and LLIN with synergist piperonyl butoxide (PBO-LLIN) are novel tools that can overcome the problems of behavioral variation of net use and metabolic resistance to insecticide, respectively. The two have been shown to reduce malaria prevalence when used independently. Integration of these two tools (i.e., ceiling nets made with PBO-LLIN or Olyset®Plus ceiling nets) appears promising in further reducing the malaria burden.

METHODS

A cluster-randomized controlled trial is designed to assess the effect of Olyset®Plus ceiling nets on reducing malaria prevalence in children on Mfangano Island in Homa Bay County, where malaria transmission is moderate. Olyset®Plus ceiling nets will be installed in 1315 residential structures. Malaria parasitological, entomological, and serological indicators will be measured for 12 months to compare the effectiveness of this new intervention against conventional LLIN in the control arm.

DISCUSSION

Wider adoption of Olyset®Plus ceiling nets to complement existing interventions may benefit other malaria-endemic counties and be incorporated as part of Kenya's national malaria elimination strategy.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000045079. Registered on 4 August 2021.

Patterns of distress and psychosocial support 2 years post-displacement following a natural disaster in a lower middle income country

Background

Displacement due to natural disaster exposure is a major source of distress, and disproportionately affects people in low- and middle-income countries (LMICs). Public mental health resources following natural disasters and displacement are often limited in LMICs. In 2017, the population of one island in Vanuatu, a lower-middle income country, was displaced due to volcanic activity. Following the launch of a public mental health policy in 2009, psychosocial support interventions are increasingly available, providing an opportunity to assess relationships with distress following displacement.

Methods

440 people contributed data. We assessed distress using a local adaptation of the Impact of Event Scale-Revised, and types of psychosocial support available and received, including from health professionals, support groups, and traditional networks such as chiefs, traditional healers, and church leaders. We analyzed relationships between distress and psychosocial support, controlling for sociodemographic covariates.

Results

Professional and group support was reported available by 86.8-95.1% of participants. Traditional support networks were widely used, especially by men. Availability of professional support predicted lower distress among men (p < 0.001) and women (p = 0.015) ( η p 2 = 0.026-0.083). Consulting church leaders for psychosocial support was associated with higher distress among men (p = 0.026) and women (p = 0.023) ( η p 2 = 0.024-0.031). Use of professional and group support was lower than reported availability.

Discussion

Increased collaboration between professional and traditional support networks could help respond to mental health needs following natural disasters in LMICs with limited infrastructure. Providing training and resources to church leaders might be a specific target for improvement. Promoting use of available services represents a continued public health need.

Potential application of the haematology analyser XN-31 prototype for field malaria surveillance in Kenya

Background

Simple and accurate diagnosis is a key component of malaria control programmes. Microscopy is the current gold standard, however it requires extensive training and the results largely rely on the skill of the microscopists. Malaria rapid diagnostic tests (RDT) can be performed with minimal training and offer timely diagnosis, but results are not quantitative. Moreover, some Plasmodium falciparum parasites have evolved and can no longer be detected by existing RDT. Developed by the Sysmex Corporation, the XN-31 prototype (XN-31p) is an automated haematology analyser capable of detecting Plasmodium-infected erythrocytes and providing species differentiation and stage specific parasite counts in venous blood samples without any preparation in approximately one minute. However, factors such as stable electricity supply in a temperature-controlled room, cost of the instrument and its initial set-up, and need for proprietary reagents limit the utility of the XN-31p across rural settings. To overcome some of these limitations, a hub and spoke diagnosis model was designed, in which peripheral health facilities were linked to a central hospital where detection of Plasmodium infections by the XN-31p would take place. To explore the feasibility of this concept, the applicability of capillary blood samples with the XN-31p was evaluated with respect to the effect of sample storage time and temperature on the stability of results.

Methods

Paired capillary and venous blood samples were collected from 169 malaria-suspected outpatients in Homa Bay County Referral Hospital, Kenya. Malaria infections were diagnosed with the XN-31p, microscopy, RDT, and PCR. Capillary blood samples were remeasured on the XN-31p after 24 h of storage at either room (15–25 °C) or chilled temperatures (2–8 °C).

Results

Identical results in malaria diagnosis were observed between venous and capillary blood samples processed immediately after collection with the XN-31p. Relative to PCR, the sensitivity and specificity of the XN-31p with capillary blood samples were 0.857 and 1.000, respectively. Short-term storage of capillary blood samples at chilled temperatures had no adverse impact on parasitaemia and complete blood counts (CBC) measured by the XN-31p.

Conclusion

These results demonstrate the potential of the XN-31p to improve routine malaria diagnosis across remote settings using a hub and spoke model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04259-7.

P–557 Trophectoderm biopsy technique and rate of mosaicism in human blastocysts

Study question

Do different trophectoderm biopsy techniques affect mosaicism rate in human blastocysts?

Summary answer

No statistical significance was found between biopsy techniques and mosaicism rate. However, an increase in mosaicism rate was observed when the flicking technique was used.

What is known already

Mosaicism is defined as two or more distinct cell lines within an embryo. Recent advances in Next Generation Sequencing (NGS) technology with an increased sensitivity allows a higher accuracy in quantification of mosaic levels in biopsied cells. The incidence of mosaicism is widely debated as there are many attributing technical and biological factors. Since, trophectoderm biopsy is a technically challenging process, it is crucial to ensure that the both biopsied cells and blastocyst suffers minimal damage during biopsy.

Study design, size, duration

This is a prospective study involving 222 patients (age range= 18–44, mean age= 31.5) who underwent IVF cycles in Alpha IVF, Malaysia from March 2019 to August 2019. Six hundred and sixty-eight (668) of the blastocysts were biopsied on Day 5 (Group 1) while 177 blastocysts were biopsied on Day 6 (Group 2). The blastocysts in these groups were further categorised into their corresponding biopsy techniques: (A) laser+pulling; (B) laser+flicking; (C) flicking only.

Participants/materials, setting, methods

Blastocysts which were at least fair graded (Gardner, 1999) were biopsied and vitrified (Cryotec, Japan). The number of biopsied cells ranged from 5 to 10 cells. All biopsied trophectoderm samples were subjected to Preimplantation Genetic Testing for Aneuploidy (PGT-A) with Next Generation Sequencing (NGS) (Ion Torrent, USA). Chromosomal mosaicism analysis was done using ReproSeq Mosaic PGS w1.1 workflow. Trophectoderm biopsied sample which were tested to have 20% to 80% aneuploid cells were reported as mosaic.

Main results and the role of chance

In Group 1, the mosaicism rates for biopsy technique A, B and C were 23.3% (104/446), 28.2% (58/206) and 37.5% (6/16) respectively. In Group 2, the mosaicism rates for biopsy technique A, B and C were 14.6% (7/48), 19.5% (23/118) and 27.3% (3/11) respectively. There were no significant differences (p &gt; 0.05) in mosaicism rates between all study groups and subgroups.

Limitations, reasons for caution

Although no statistical significance was found between trophectoderm biopsy techniques and the prevalence of mosaicism, there is a trend of an increase in mosaicism rate when the flicking technique was used. Therefore, further studies with a larger sample size should be undertaken.

Wider implications of the findings: Our study demonstrates a trend in the decrease of mosaicism rate when laser pulses was used to loosen the cell junction of targeted cells. Hence, in place of the flicking method alone, laser pulses should be applied during trophectoderm biopsy if our findings are confirmed in a larger controlled study.

Trial registration number

Not applicable

P–148 Effect of additional laser assisted drilling (LAD) during trophectoderm (TE) biopsy on mosaicism rate

Study question

Does applying additional LAD during TE biopsy cause higher mosaicism rate in blastocysts?

Summary answer

Applying LAD during TE biopsy to create additional zona opening will produce more mosaic blastocysts.

What is known already

In Alpha IVF, laser assisted hatching (LAH) was done on day3 after ICSI for all pre-implantation genetic testing for aneuploidy (PGT-A) cycles. TE biopsy techniques used were laser+pulling (L+P), laser+flicking (L+F) and flicking only (F). At the time of biopsy, an extra step of creating additinonal artificial opening by LAD may be required when (a) blastocyst has very little herniated cells; (b) inner cell mass (ICM) is at the hatching point or biopsy site. Our internal study showed that biopsy using different techniques (L+P, L+F and F) does not affect mosaicism rate.

Study design, size, duration

This prospective study was designed to evaluate the effect of additional LAD during TE biopsy on the mosaicism rate. This study was conducted between 11th March–19th August 2019. Four hundred forty-three (443) patients had undergone oocyte retrieval and blastocyst culture after intracytoplasmic injection (ICSI) was done. A total of 824 hatching blastocyst (BG5) and fully hatched blastocyst (BG6) with at least a Grade A or Grade B TE (Gardner’s grading) were included in this study.

Participants/materials, setting, methods

LAH was done on day3 post-ICSI while biopsy was done on day5 and/or day6 for PGT-A. Laser pulse length used during LAH and biopsy was fixed at 400ms. The biopsied blastocysts were classified into 3 groups: (A) BG6 (n = 79), (B) BG5 without additional LAD during biopsy (n = 713) and (C) BG5 with additional LAD (n = 32). The number of biopsied cells ranged from 5–10 cells. Biopsied cells were tested using Next Generation Sequencing (Ion Torrent, USA).

Main results and the role of chance

The mosaicism rates for Group A, B and C were 19.0% (15/79), 23.4% (167/713) and 39.5% (15/38) respectively. Mosaicism rates of Group A and B were comparable (p = 0.4807), whilst Group C had significant higher mosaicism rate compared to Group A and B (p = 0.0238 and p = 0.0319 respectively). The mean age of Group A, B and C were 31.1, 31.4 and 27.1 respectively. The mean age between these 3 groups were not statistically significant (A vs B, p = 0.0713; A vs C, p = 0.06727; and B vs C, p = 0.4408).

Limitations, reasons for caution

Additional LAD during TE biopsy maybe be a confounding variable which affects the mosaicism rate. Moreover, the increase in mosaicism rate could be due to other unknown factors. A larger sample size is needed to confirm the results.

Wider implications of the findings: Based on our study, additional LAD during TE biopsy is not recommended as this may increase mosaicism rate. Biopsy should be done when the blastocyst has more herniated cell or when the ICM leaves the hatching point/biopsy site.

Trial registration number

Not applicable

Relationships between mental health and diet during pregnancy and birth outcomes in a lower-middle income country: "Healthy mothers, healthy communities" study in Vanuatu

Poor maternal mental health during pregnancy is associated with adverse birth outcomes, including lower birthweight and gestational age. However, few studies assess both mental health and diet, which might have interactive effects. Furthermore, most studies are in high-income countries, though patterns might differ in low- and middle-income countries (LMICs).

OBJECTIVES

To analyze relationships between mental health and diet during pregnancy with birth outcomes in Vanuatu, a lower-middle income country.

METHODS

We assessed negative emotional symptoms of depression, anxiety, and stress (referred to as "distress") and dietary diversity during pregnancy, and infant weight and gestational age at birth, among 187 women. We used multivariate linear regression to analyze independent and interactive relationships between distress, dietary diversity, and birth outcomes, controlling for sociodemographic and maternal health covariates.

RESULTS

There were no direct linear relationships between dietary diversity or distress with infant birthweight or gestational age, and no curvilinear relationships between distress and infant outcomes. We observed interactive relationships between distress and dietary diversity on birthweight, explaining 2.1% of unique variance (P = .024). High levels of distress predicted lower birthweights among women with low dietary diversity. These relationships were not evident among women with moderate or high dietary diversity.

CONCLUSIONS

Relationships between mental health and diet might underlie inconsistencies in past studies of prenatal mental health and birthweight. Results highlight the importance of maternal mental health on birthweight in LMICs. Interactive relationships between mental health and diet might ultimately point to new intervention pathways to address the persistent problem of low birthweight in LMICs.

Maintaining breast cancer care in the face of COVID-19

The battle of COVID-19 is currently at different levels of intensity in each country and even each city. The authors have prepared succinct recommendations regarding the care of patients with breast cancer, divided into phases that can easily be adapted to each units' needs and resources, and stepped up or stepped down according to escalating and de-escalating circumstances. The structure can also be transposed easily to different cancer types, enabling continued provision of best standards of care despite unprecedented stressors. Surgery must go on.

Malaria resurgence after significant reduction by mass drug administration on Ngodhe Island, Kenya

Although WHO recommends mass drug administration (MDA) for malaria elimination, further evidence is required for understanding the obstacles for the optimum implementation of MDA. Just before the long rain in 2016, two rounds of MDA with artemisinin/piperaquine (Artequick) and low-dose primaquine were conducted with a 35-day interval for the entire population of Ngodhe Island (~500 inhabitants) in Lake Victoria, Kenya, which is surrounded by areas with moderate and high transmission. With approximately 90% compliance, Plasmodium prevalence decreased from 3% to 0% by microscopy and from 10% to 2% by PCR. However, prevalence rebounded to 9% by PCR two months after conclusion of MDA. Besides the remained local transmission, parasite importation caused by human movement likely contributed to the resurgence. Analyses of 419 arrivals to Ngodhe between July 2016 and September 2017 revealed Plasmodium prevalence of 4.6% and 16.0% by microscopy and PCR, respectively. Risk factors for infection among arrivals included age (0 to 5 and 11 to 15 years), and travelers from Siaya County, located to the north of Ngodhe Island. Parasite importation caused by human movement is one of major obstacles to sustain malaria elimination, suggesting the importance of cross-regional initiatives together with local vector control.

Family medicine vocational training and career satisfaction in Hong Kong

BACKGROUND

Postgraduate vocational training in family medicine (FM) is essential for physicians to build capacity and develop quality primary care. Inadequate standards in training and curriculum development can contribute to poor recruitment and retention of doctors in primary care. This study aimed to investigate: 1) the satisfaction level of doctors regarding vocational training in family medicine and associated demographics; and 2) the satisfaction level of doctors regarding their family medicine career and associated factors.

METHOD

This is a cross sectional study of all family medicine physicians across all government-funded primary care clinics (GOPCs). The study questionnaire consisted of items from a standardized and validated physician survey named the Physician Worklife Survey (PWS) (Konrad et al., Med Care, 1999). We selected three scales (7 items) relating to global job satisfaction, global career satisfaction and global specialty (family medicine) satisfaction with additional items on training and demographics. All significant variables in bivariate analyses were further examined using stepwise logistic regression.

RESULTS

Out of 424 eligible family medicine physicians, 368 physicians successfully completed the questionnaire. The response rate was 86.8%. Most participants were male (52.6%), were aged between 35 and 44 years (55.5%), were FM specialists (42.4%), graduated locally (86.2%), and had postgraduate qualifications. Eighty-two percent (82%) of participants were satisfied with their training. Having autonomy and protected time for training were associated with satisfaction with FM training. Satisfaction with family medicine as a career was correlated with physicians' satisfaction with their current job. Doctors who did not enroll in training (p < 0.001) and physicians who were older (p = 0.023) were significantly less satisfied. Stepwise multivariate regression showed that doctors who subjectively believed their training as "broad and in depth' had higher career satisfaction (p < 0.001).

CONCLUSION

Overall, the satisfaction level of physicians on current family medicine training in Hong Kong was high. Having autonomy and protected time for training is associated with higher training satisfaction levels. Perceiving FM training as "broad and in-depth" is associated with higher family medicine career satisfaction.

Psychosocial support during displacement due to a natural disaster: relationships with distress in a lower-middle income country

Background

Past studies show relationships between disaster-related displacement and adverse psychosocial health outcomes. The development of psychosocial interventions following displacement is thus increasingly prioritized. However, data from low- and middle-income countries (LMICs) are lacking. In October 2017, the population of Ambae Island in Vanuatu, a lower-middle income country, was temporarily displaced due to volcanic activity. We analyzed distress among adults displaced due to the event and differences based on the psychosocial support they received.

Methods

Data on experiences during displacement, distress and psychosocial support were collected from 443 adults 2–3 wk after repatriation to Ambae Island. Four support categories were identified: Healthcare professional, Traditional/community, Not available and Not wanted. We analyzed differences in distress by sex and group using one-way ANOVA and generalized linear models.

Results

Mean distress scores were higher among women (1.90, SD=0.97) than men (1.64, SD=0.98) (p<0.004). In multivariate models, psychosocial support group was associated with distress among women (p=0.033), with higher scores among women who reported no available support compared with every other group. Both healthcare professional and traditional support networks were widely used.

Conclusions

Women might be particularly vulnerable to distress during disaster-related displacement in LMICs, and those who report a lack of support might be at greater risk. Both healthcare professional and traditional networks provide important sources of support that are widely used and might help to ameliorate symptoms.

Coming to grips with economic development: Variation in adult hand grip strength during health transition in Vanuatu

OBJECTIVES

To determine whether (1) maximal handgrip strength (HGS) is associated with inter-island level of economic development in Vanuatu, (2) how associations between island of residence and HGS are mediated by age, sex, body size/composition, and individual sociodeomographic variation, and (3) whether HGS is predictive of hypertension.

MATERIAL AND METHODS

HGS was collected from 833 adult (aged 18 and older) men and women on five islands representing a continuum of economic development in Vanuatu. HGS was measured using a handheld dynamometer. Participants were administered in an extensive sociobehavioral questionnaire and were also assessed for height, weight, percent body fat, forearm skinfold thickness, forearm circumference, and blood pressure.

RESULTS

HGS was significantly greater in men than in women regardless of island of residence. HGS was also significantly positively associated with inter-island level of economic development. Grip strength-to-weight ratio was not different across islands except in older individuals, where age-related decline occurred primarily on islands with greater economic development. HGS significantly declined with age in both men and women.

CONCLUSION

HGS is positively associated with modernization in Vanuatu, but the relationship between HGS and modernization is largely due to an association of both variables with increased body size on more modernized islands. Further research on the role of individual variation in diet and physical activity are necessary to clarify the relationship between HGS and modernization.

Spinal cord stimulation for chronic non-cancer pain: a review of current evidence and practice

Spinal cord stimulation provides analgesia through electrical stimulation of the dorsal column of the spinal cord via electrode leads placed into the epidural space. In traditional tonic stimulation, a painful sensation is replaced with paraesthesia. Spinal cord stimulation is effective in reducing neuropathic pain, enhancing function, and improving quality of life in different chronic pain conditions. Currently, there is most evidence to support its use for failed back surgery syndrome when multidisciplinary conventional management is unsuccessful. Temporary trial leads are inserted in carefully selected patients to test their responsiveness prior to permanent implantation. Newer neuromodulation modalities are now available. These include burst stimulation, high-frequency stimulation, and dorsal root ganglion stimulation. Results are encouraging to date, and they may provide superior analgesia and cover for deficiencies of traditional tonic stimulation. Although complications are not uncommon, they are rarely life threatening or permanently disabling. Nonetheless, device removal is occasionally needed.

Ductal carcinoma in-situ arising within benign phyllodes tumours

Ductal carcinoma in situ arising within a benign phyllodes tumour is a rare neoplasm of the breast. We present a case of a 19-year-old woman who had a right breast lump for six months with the above diagnosis together with a mini-review of the literature. Ultrasound revealed a 5-cm breast lump and core biopsy revealed ductal carcinoma in situ. She underwent wide local excision of the breast lump with clear margins. Final histology confirmed ductal carcinoma in situ within a fibroepithelial lesion consistent with a benign phyllodes tumour. To our knowledge, this is the youngest case of ductal carcinoma in situ arising in a phyllodes tumour to have been reported so far.

Improvement of malaria diagnostic system based on acridine orange staining

BACKGROUND

Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent.

METHODS

The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya.

RESULTS

Without staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard.

CONCLUSIONS

Consistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.

Hepatic Portal Venous Gas in a Patient with Penetrating Injuries

Hepatic portal venous gas (HPVG) refers to the branching area of low attenuation extending to within 2 cm of the liver capsule in computed tomography scan. The most common causes of HPVG are mesenteric ischaemia in adults and necrotising enterocolitis in infants. HPVG in trauma patients is mostly reported in cases of blunt abdominal trauma. We present a deceased patient who had chest and abdominal wall penetrating injuries with concomitant hypovolemic shock. A computed tomography scan revealed HPVG and pulmonary artery air emboli. The mechanism of the presentation of HPVG in this patient and the possible cause of death would be discussed. (Hong Kong j.emerg.med. 2013;20:382-384)

A Case of Acute Calcific Tendinitis of the Hand: An Uncommon Condition that is Easily Overlooked and Misdiagnosed

Acute calcific tendinitis of the hand is uncommon, yet it has a high rate of misdiagnosis as it resembles other conditions such as fractures, inflammatory and infectious causes that give rise to pain and swelling in the hand. We present a case of acute calcific tendinitis in a middle age woman affecting the extensor pollicis longus to raise awareness of this uncommon, but easily treatable cause of pain and swelling. This case was first diagnosed as septic arthritis of the interphalangeal joint of the thumb. Correct diagnosis was made after careful review of history, physical examination findings, laboratory results and radiographs. (Hong Kong j. emerg.med. 2015;22:316-319)

Secular change in adult stature associated with modernization in Vanuatu

OBJECTIVE

To determine whether: (1) there is a secular increase in adult stature in Vanuatu, and (2) whether adult stature is positively associated with modernization in Vanuatu.

METHODS

This study reports on stature measurements collected on 650 adult (age > 17 years) men and women from four islands of varying economic development in Vanuatu. Measurements were collected as part of the Vanuatu Health Transitions Research Project in 2007 and 2011.

RESULTS

Stature increased significantly in adults born between the 1940s and 1960s in Vanuatu, before leveling off in those born between the 1970s and 1990s. Adults are significantly taller on Efate, the most modernized island in the study sample, than on the less economically developed islands.

CONCLUSIONS

Modernization is likely associated with improvements in child growth in Vanuatu, as assessed by gains in adult stature.

Serological measures to assess the efficacy of malaria control programme on Ambae Island, Vanuatu

Background

Seroepidemiology can provide evidence for temporal changes in malaria transmission and is an important tool to evaluate the effectiveness of control interventions. During the early 2000s, Vanuatu experienced an acute increase in malaria incidence due to a lapse in funding for vector control. After the distribution of subsidised insecticide-treated nets (ITNs) resumed in 2003, malaria incidence decreased in the subsequent years. This study was conducted to find the serological evidence supporting the impact of ITN on exposure to Anopheles vector bites and parasite prevalence.

Methods

On Ambae Island, blood samples were collected from 231 and 282 individuals in 2003 and 2007, respectively. Parasite prevalence was determined by microscopy. Antibodies to three Plasmodium falciparum (PfSE, PfMSP-1₁₉, and PfAMA-1) and three Plasmodium vivax (PvSE, PvMSP-1₁₉, and PvAMA-1) antigens, as well as the Anopheles-specific salivary antigen gSG6, were detected by ELISA. Age-specific seroprevalence was analysed using a reverse catalytic modelling approach to estimate seroconversion rates (SCRs).

Results

Parasite rate decreased significantly (P < 0.001) from 19.0% in 2003 to 3.2% in 2007, with a shift from P. falciparum predominance to P. falciparum-P. vivax co-dominance. Significant (P < 0.001) decreases were observed in seroprevalence to all three P. falciparum antigens but only two of three P. vivax antigens (except PvAMA-1; P = 0.153), consistent with the more pronounced decrease in P. falciparum prevalence. Seroprevalence to gSG6 also decreased significantly (P < 0.001), suggesting that reduced exposure to vector bites was important to the decrease in parasite prevalence between 2003 and 2007. Analyses of age-specific seroprevalence showed a three-fold decrease in P. falciparum transmission, but the evidence for the decrease in P. vivax transmission was less clear.

Conclusions

Serological markers pointed to the effectiveness of ITNs in reducing malaria prevalence on Ambae Island between 2003 and 2007. The recombinant gSG6 antigen originally developed to indicate exposure to the Afrotropical vector An. gambiae may be used in the Pacific to complement the traditional measure of entomological inoculation rate (EIR).

Rolling Tobacco in Banana Leaves, Newspaper, or Copybook Paper Associated With Significant Reduction in Lung Function in Vanuatu

In addition to the widespread availability of packaged cigarettes, the inhabitants of island nations of the Southwest Pacific frequently smoke commercially available loose tobacco using manufactured rolling papers, as well as locally grown tobacco rolled in manufactured rolling paper or wrapped in leaves, copybook paper, and newspaper. In this study, Vanuatu men who smoked local tobacco rolled in leaves, copybook paper, or newspaper showed significantly lower forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC ratios than men who smoked packaged cigarettes, store-bought tobacco rolled in manufactured rolling paper, or who smoked locally grown tobacco rolled in manufactured rolling papers. The addition of toxins from these unusual tobacco-wrapping media produces lung function deficits similar to the pattern noted among tobacco smokers who also inhale smoke from burning biomass. Thus, public health initiatives should consider including strategies addressing the use of wrapping media among smokers in South Pacific island societies.

Selections, frameshift mutations, and copy number variation detected on the surf 4.1 gene in the western Kenyan Plasmodium falciparum population

Background

Plasmodium falciparum SURFIN_4.1 is a putative ligand expressed on the merozoite and likely on the infected red blood cell, whose gene was suggested to be under directional selection in the eastern Kenyan population, but under balancing selection in the Thai population. To understand this difference, surf_4.1 sequences of western Kenyan P. falciparum isolates were analysed. Frameshift mutations and copy number variation (CNV) were also examined for the parasites from western Kenya and Thailand.

Results

Positively significant departures from neutral expectations were detected on the surf_4.1 region encoding C-terminus of the variable region 2 (Var2) by 3 population-based tests in the western Kenyan population as similar in the Thai population, which was not covered by the previous analysis for eastern Kenyan population. Significant excess of non-synonymous substitutions per nonsynonymous site over synonymous substitutions per synonymous site was also detected in the Var2 region. Negatively significant departures from neutral expectations was detected on the region encoding Var1 C-terminus consistent to the previous observation in the eastern Kenyan population. Parasites possessing a frameshift mutation resulting a product without intracellular Trp-rich (WR) domains were 22/23 in western Kenya and 22/36 in Thailand. More than one copy of surf_4.1 gene was detected in western Kenya (4/24), but no CNV was found in Thailand (0/36).

Conclusions

The authors infer that the high polymorphism of SURFIN_4.1 Var2 C-terminus in both Kenyan and Thai populations were shaped-up by diversifying selection and maintained by balancing selection. These phenomena were most likely driven by immunological pressure. Whereas the SURFIN_4.1 Var1 C-terminus is suggested to be under directional selection consistent to the previous report for the eastern Kenyan population. Most western Kenyan isolates possess a frameshift mutation that would limit the expression of SURFIN_4.1 on the merozoite, but only 60% of Thai isolates possess this frameshift, which would affect the level and type of the selection pressure against this protein as seen in the two extremities of Tajima’s D values for Var1 C-terminus between Kenyan and Thai populations. CNV observed in Kenyan isolates may be a consequence of this frameshift mutation to increase benefits on the merozoite surface.

High and Heterogeneous Prevalence of Asymptomatic and Sub-microscopic Malaria Infections on Islands in Lake Victoria, Kenya

Kenya is intensifying its national efforts in malaria control to achieve malaria elimination. Detailed characterization of malaria infection among populations living in the areas where the disease is endemic in Kenya is a crucial priority, especially for planning and evaluating future malaria elimination strategy. This study aimed to investigate the distribution and extent of malaria infection on islands in Lake Victoria of Kenya to aid in designing new interventions for malaria elimination. Five cross-sectional surveys were conducted between January 2012 and August 2014 on four islands (Mfangano, Takawiri, Kibuogi and Ngodhe) in Lake Victoria and a coastal mainland (Ungoye). Malaria prevalence varied significantly among settings: highest in Ungoye, followed by the large island of Mfangano and lowest in the three remaining small islands. Of the 3867 malaria infections detected by PCR, 91.8% were asymptomatic, 50.3% were sub-microscopic, of which 94% were also asymptomatic. We observed geographical differences and age dependency in both proportion of sub-microscopic infections and asymptomatic parasite carriage. Our findings highlighted the local heterogeneity in malaria prevalence on islands and a coastal area in Lake Victoria, and provided support for the inclusion of mass drug administration as a component of the intervention package to eliminate malaria on islands.

Ownership of consumer electronics is associated with measures of adiposity during health transition in Vanuatu

OBJECTIVE

The Republic of Vanuatu, like many developing nations, is undergoing a rapid health transition. Our previous study identified several behavioral risk factors for the rising prevalence of obesity. Unexpectedly, daily time spent using television and radio was revealed as a protective factor for obesity in 2007. In this study, we sought to explore associations between ownership of consumer electronics (CE) and measures of adiposity in Vanuatu in 2011.

METHODS

We surveyed 873 adults from five islands varying in level of economic development. Height, weight, and waist circumferences; triceps, subscapular, and suprailiac skinfolds; and percent body fat by bioelectrical impedance were measured. Ownership of eight types of CE, diet through 24-h dietary recall and leisure-time activity patterns were assessed using a questionnaire.

RESULTS

Participants from more developed islands owned more types of CE, and revealed higher measures of adiposity on average as well as higher prevalence of obesity/central obesity. When controlling for demographic factors, and dietary and activity patterns, increased measures of adiposity and risk for obesity/central obesity were associated with ownership of cellphones, music players, televisions, video players, microwaves, and/or refrigerators. Positive correlations between CE ownership and measures of adiposity were mainly observed among men on the two most developed islands.

CONCLUSIONS

The results of this study indicate a possible role of CE use in the rising prevalence of obesity and the shift to a sedentary lifestyle in Vanuatu and many other modernizing regions, where prevention efforts including education on healthy use of CE are imperative.

Association between dietary fibre intake with cancer and all-cause mortality among 15 740 adults: the National Health and Nutrition Examination Survey III

BACKGROUND

Few prospective studies have examined the longitudinal associations of total dietary fibre intake and water insoluble and soluble fibres with cancer and all-cause mortality. The present study aimed to examine these associations.

METHODS

We studied the effects of total dietary fibre intake and water insoluble and soluble fibres on cancer and all-cause mortality, using data from 15 740 adult participants [mean (SD) age: 44.53 (19.22) years, 46.60% male] in the National Health and Nutrition Examination Survey (NHANES) III, 1988-1994, who had completed a 24-h dietary recall. Death certificate data were obtained up to 2006. Participants had been followed for 13.74 years on average. Cox regression was used to estimate the hazard ratios (HRs) of total dietary, insoluble and soluble fibres on cancer and all-cause mortality, with the first quartile as the reference group, adjusted for demographics, lifestyle and dietary factors.

RESULTS

Relative to those in the first quartile of total fibre intake, only the third quartile was associated with all-cause mortality, with an adjusted HR of 0.87 [95% confidence interval (CI) = 0.79, 0.97, P = 0.021], and cancer mortality, with an adjusted HR of 0.77 (95% CI = 0.61, 0.99, P = 0.05). The third quartile of insoluble fibre intake was associated with cancer mortality, with an adjusted HR of 0.76 (95% CI = 0.60, 0.96, P = 0.023), and colorectal-anal cancer mortality (in grouped data as provided for public use), with an adjusted HR of 0.42 (95% CI = 0.19, 0.91, P = 0.03).

CONCLUSIONS

Dietary fibre showed protective benefits in terms of mortality risk. Investigating the mechanisms and components of dietary fibres underlying the different protective benefits remains an important consideration for research on fibre-mortality risk.

Plasmodium vivax and Plasmodium falciparum at the crossroads of exchange among islands in Vanuatu: implications for malaria elimination strategies

Understanding the transmission and movement of Plasmodium parasites is crucial for malaria elimination and prevention of resurgence. Located at the limit of malaria transmission in the Pacific, Vanuatu is an ideal candidate for elimination programs due to low endemicity and the isolated nature of its island setting. We analyzed the variation in the merozoite surface protein 1 (msp1) and the circumsporozoite protein (csp) of P. falciparum and P. vivax populations to examine the patterns of gene flow and population structures among seven sites on five islands in Vanuatu. Genetic diversity was in general higher in P. vivax than P. falciparum from the same site. In P. vivax, high genetic diversity was likely maintained by greater extent of gene flow among sites and among islands. Consistent with the different patterns of gene flow, the proportion of genetic variance found among islands was substantially higher in P. falciparum (28.81–31.23%) than in P. vivax (-0.53–3.99%). Our data suggest that the current island-by-island malaria elimination strategy in Vanuatu, while adequate for P. falciparum elimination, might need to be complemented with more centrally integrated measures to control P. vivax movement across islands.

Improved detection of malaria cases in island settings of Vanuatu and Kenya by PCR that targets the Plasmodium mitochondrial cytochrome c oxidase III (cox3) gene

Detection of sub-microscopic parasitemia is crucial for all malaria elimination programs. PCR-based methods have proven to be sensitive, but two rounds of amplification (nested PCR) are often needed to detect the presence of Plasmodium DNA. To simplify the detection process, we designed a nested PCR method whereby only the primary PCR is required for the detection of the four major human Plasmodium species. Primers designed for the detection of the fifth species, Plasmodium knowlesi, were not included in this study due to the absence of appropriate field samples. Compared to the standard 18S rDNA PCR method, our cytochrome c oxidase III (cox3) method detected 10-50% more cases while maintaining high sensitivities (1.00) for all four Plasmodium species in our samples from Vanuatu (n=77) and Kenya (n=76). Improvement in detection efficiency was more substantial for samples with sub-microscopic parasitemia (54%) than those with observable parasitemia (10-16%). Our method will contribute to improved malaria surveillance in low endemicity settings.

Effect of laser treatment on the attachment and viability of mesenchymal stem cell responses on shape memory NiTi alloy

The objectives of this study were to investigate the effect of laser-induced surface features on the morphology, attachment and viability of mesenchymal stem cells (MSCs) at different periods of time, and to evaluate the biocompatibility of different zones: laser-melted zone (MZ), heat-affected zone (HAZ) and base metal (BM) in laser-treated NiTi alloy. The surface morphology and composition were studied by scanning electron microscope (SEM) and X-ray photoemission spectroscopy (XPS), respectively. The cell morphology was examined by SEM while the cell counting and viability measurements were done by hemocytometer and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. The results indicated that the laser-induced surface features, such as surface roughening, presence of anisotropic dendritic pattern and complete surface Ni oxidation were beneficial to improve the biocompatibility of NiTi as evidenced by the highest cell attachment (4 days of culture) and viability (7 days of culture) found in the MZ. The biocompatibility of the MZ was the best, followed by the BM with the HAZ being the worst. The defective and porous oxide layer as well as the coarse grained structure might attribute to the inferior cell attachment (4 days of culture) and viability (7 days of culture) on the HAZ compared with the BM which has similar surface morphology.

Psychology of earthquake-induced stress cardiomyopathy, myocardial infarction and non-cardiac chest pain

AIMS

To compare psychological factors in patients presenting to hospital with earthquake-induced stress cardiomyopathy, myocardial infarction (MI) and non-cardiac chest pain. We hypothesised that patients with stress cardiomyopathy and non-cardiac chest pain would be more psychologically vulnerable than those with MI.

METHODS

Cardiology admitting staff in the week following the September 2010 Christchurch earthquake prospectively identified patients with earthquake-precipitated chest pain. Males were excluded. All consenting women met diagnostic criteria for one of the three conditions. Patients underwent a semistructured interview with a senior clinical psychologist who was blind to the cardiac diagnosis. Premorbid psychological factors, experience of the earthquake and psychological response were assessed using a range of validated tools.

RESULTS

Seventeen women were included in the study, six with stress cardiomyopathy, five with MI and six with non-cardiac chest pain. Earthquake experiences were notably similar across the groups. Patients with non-cardiac chest pain scored high on the hospital anxiety and depression scale, the health anxiety questionnaire, the Eysenck neuroticism scale and the Impact of Event scale. Women with stress cardiomyopathy scored as the most psychologically robust. Depression and extroversion scores were the same across groups.

CONCLUSION

Our hypothesis was incorrect. Women with non-cardiac chest pain following an earthquake have higher anxiety and neuroticism scores than women with either MI or stress cardiomyopathy. Stress cardiomyopathy following an earthquake is not specific to psychologically vulnerable women. The psychology of natural disaster-induced stress cardiomyopathy may differ from that of sporadic cases.

Perceptions of coronary heart disease: the development and psychometric testing of a measurement scale

Individuals' perceptions of coronary heart disease (CHD) have implications for the ways in which they respond to the disease, process risks, make decisions, and take action to reduce CHD risks. This study aimed to develop and evaluate the psychometric properties of the perceptions of coronary heart disease scale (PCS) among a Hong Kong Chinese population. A cross-sectional study was conducted using a convenient sample (n = 232) of participants recruited from a variety of catchments including public domains, a cardiac unit, and a cardiac rehabilitation and prevention center. Exploratory factor analysis identified a nine-item, two-factor model that accounted for 52.5% of the total explained variance. The two factors were the perceived risk (five items) and perceived seriousness (four items) of CHD. The PCS demonstrated good content validity; acceptable total, and subscale internal consistency (.73, .61 - .81); and significant contrast-group differences with higher levels of CHD perceptions among males (p = .002), younger participants (p < .001), and those with higher educational levels (p < .001), suggesting excellent construct validity. The newly developed PCS demonstrates acceptable psychometric properties as a short measurement scale, which supports its use in future research. Future validation of this scale is warranted.

The origins and genetic distinctiveness of the Chamorros of the Marianas Islands: an mtDNA perspective

BACKGROUND

Archaeological and linguistic evidence suggests the Marianas Islands were settled around 3,600 years before present (ybp) from Island Southeast Asia (ISEA). Around 1,000 ybp latte stone pillars and the first evidence of rice cultivation appear in the Marianas. Both traditions are absent in the rest of prehistoric Oceania.

OBJECTIVE

To examine the genetic origins and postsettlement gene flow of Chamorros of the Marianas Islands.

METHODS

To infer the origins of the Chamorros we analyzed ∼360 base pairs of the hypervariable-region 1 (HVS1) of mitochondrial DNA from 105 Chamorros from Guam, Rota, and Saipan, and the complete mitochondrial genome of 32 Guamanian Chamorros, and compared them to lineages from ISEA and neighboring Pacific archipelagoes from the database.

RESULTS

Results reveal that 92% of Chamorros belong to haplogroup E, also found in ISEA but rare in Oceania. The two most numerous E lineages were identical to lineages currently found in Indonesia, while the remaining E lineages differed by only one or two mutations and all were unique to the Marianas. Seven percent of the lineages belonged to a single Chamorro-specific lineage within haplogroup B4, common to ISEA as well as Micronesia and Polynesia.

CONCLUSIONS

These patterns suggest a small founding population had reached and settled the Marianas from ISEA by 4,000 ybp, and developed unique mutations in isolation. A second migration from ISEA may have arrived around 1,000 ybp, introducing the latte pillars, rice agriculture and the homogeneous minority B4 lineage.

Diversity of Plasmodium falciparum chloroquine resistance transporter (pfcrt) exon 2 haplotypes in the Pacific from 1959 to 1979

Nearly one million deaths are attributed to malaria every year. Recent reports of multi-drug treatment failure of falciparum malaria underscore the need to understand the molecular basis of drug resistance. Multiple mutations in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) are involved in chloroquine resistance, but the evolution of complex haplotypes is not yet well understood. Using over 4,500 archival human serum specimens collected from 19 Pacific populations between 1959 and 1979, the period including and just prior to the appearance of chloroquine treatment failure in the Pacific, we PCR-amplified and sequenced a portion of the pfcrt exon 2 from 771 P. falciparum-infected individuals to explore the spatial and temporal variation in falciparum malaria prevalence and the evolution of chloroquine resistance. In the Pacific, the prevalence of P. falciparum varied considerably across ecological zones. On the island of New Guinea, the decreases in prevalence of P. falciparum in coastal, high-transmission areas over time were contrasted by the increase in prevalence during the same period in the highlands, where transmission was intermittent. We found 78 unique pfcrt haplotypes consisting of 34 amino acid substitutions and 28 synonymous mutations. More importantly, two pfcrt mutations (N75D and K76T) implicated in chloroquine resistance were present in parasites from New Hebrides (now Vanuatu) eight years before the first report of treatment failure. Our results also revealed unexpectedly high levels of genetic diversity in pfcrt exon 2 prior to the historical chloroquine resistance selective sweep, particularly in areas where disease burden was relatively low. In the Pacific, parasite genetic isolation, as well as host acquired immune status and genetic resistance to malaria, were important contributors to the evolution of chloroquine resistance in P. falciparum.

Differences in perceptions of coronary disease among Hong Kong Chinese: implications for the societal readiness in disease prevention

Perceptions of coronary heart disease (CHD) influence individual health behavior, which is central to preventing the disease. Not enough is known about the demographic differences in perceptions of CHD among Chinese communities. This study examined these differences in the perceived seriousness and risk of CHD among Hong Kong Chinese. A self-developed questionnaire was administered to a convenient sample (n = 236). Significant differences were identified in the perceived seriousness and risk of CHD between younger and older age groups (p < 0.001) and groups with lower and higher education levels (p < 0.001), but not between genders (p > 0.05). Over 50% of participants expressed greater concern about infectious disease than about CHD, while two-thirds to over half of female, older, and less educated participants were more concerned about stroke. This study highlighted populations with lower levels of CHD perception that need increased public education. The findings have implications for the societal readiness to establishing ongoing public healthcare strategies to increase awareness of CHD.

Systemic blood pressure, arterial stiffness and pulse waveform analysis at altitude

OBJECTIVES

Systemic arterial pressure rises on acute exposure to high altitude and changes in blood pressure (BP) and endothelial function may be important in the pathogenesis of clinical syndromes occurring at high altitude.

METHODS

Arterial BP, stiffness (SI) and tone (RI) were studied over 11 days in 17 subjects (three having mild hypertension) ascending to 3,450m and 4,770m using a non-invasive, finger photoplethysmography technique.

RESULTS

At 3,450m BP rose from mean 131/75 mmHg (SD 23/12) to 145/86 (23/12) and was maintained at this level (p < 0.001). SI did not change significantly from 8.5 m/sec (2.5) to 9.7 (3.2). RI fell during the first day at 3,450m from 74.4% (7.9) to 70.5% (13.8) (NS p > 0.05) and to 69.9% (12.0) (p < 0.02) at 4,770m but then reverted to baseline. Changes in SI and RI did not relate to changes in blood pressure. Changes in both arterial stiffness and tone were similar in those who developed AMS compared with those who did not. Baseline SI tended to be higher in the three subjects with hypertension 11.1m/sec (SD 2.7)) compared with the normotensives 8.3 m/sec (SD 2.7) (NS) and baseline RI lower 74.7% (7.0) compared with the normotensives 76.5% (8.5) (NS). Changes in SI and RI at altitude in the hypertensive subjects were similar to the non-hypertensive subjects.

CONCLUSIONS

We conclude that acute exposure temporarily affected endothelial function as measured by a change in vascular tone but this did not predict the development of AMS. The rise in arterial BP was not related to changes in arterial stiffness or tone.

Serial changes in the expression of breast cancer-related proteins in response to neoadjuvant chemotherapy

BACKGROUND

Tumour expression of cyclooxygenase-2 (COX-2), epidermal growth factor receptor (EGFR), erythroblastic leukaemia viral oncogene homologue-2 (ErbB2), Ki-67 and p53 in breast cancer are associated with poorer outcomes. We investigated in vivo changes of these proteins with neoadjuvant chemotherapy.

PATIENTS AND METHODS

Four core biopsies were taken from 100 breast cancer patients at baseline, during and upon completion of neoadjuvant chemotherapy. Immunohistochemical expression of these proteins were evaluated and correlated with clinicopathological features, clinical response and progression-free survival (PFS).

RESULTS

There was a statistically significant change from positivity to negativity in COX-2 expression with chemotherapy (P = 0.002), predominantly in clinical responders (P = 0.002). COX-2-positive tumours that remained positive had shorter PFS than those that turned negative. Estrogen receptor (ER)+ and COX-2+ tumours at baseline that remained COX-2+ fared worse than those that became COX-2 negative (PFS 27 versus 52 months, P = 0.002). No significant changes in IHC expression were observed for ER, progesterone receptor, ErbB2, EGFR, p53 or Ki67.

CONCLUSIONS

Chemotherapy induced change in COX-2 expression from positivity to negativity predominantly among clinical responders and is associated with longer PFS. Interaction between COX-2 and ER was observed, suggesting that some hormone receptor-positive patients may benefit from combining COX-2 inhibition with hormonal therapy.

Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O(2) consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

Usage of a fixed dose of radioactive iodine for the treatment of hyperthyroidism: one-year outcome in a regional hospital in Hong Kong

OBJECTIVES

To evaluate the efficacy of a fixed dose of radioactive iodine (131-I) in the treatment of thyrotoxicosis, and to identify risk factors associated with treatment failure.

DESIGN

Retrospective study.

SETTING

Thyroid Clinic of a regional hospital in Hong Kong.

PATIENTS

Patients receiving their first dose of radioactive iodine for the treatment of thyrotoxicosis during the inclusive period September 1999 to August 2004.

MAIN OUTCOME MEASURES

Relapse rate and time to relapse.

RESULTS

A total of 113 patients received a fixed dose of 5 mCi (185 MBq), 6 mCi (222 MBq), 8 mCi (296 MBq), and 10 mCi (370 MBq) 131-I in a proportion of 1:6:71:35. At 1 year, 42 (37%) of the patients had relapsed, of which 69% received a second 131-I dose. The median time to relapse after first receiving 131-I was 4 months. At 1 year, the remaining 71 (63%) of the patients were successfully treated; 46 (41%) were euthyroid, and 25 (22%) had became permanently hypothyroid. Basal free thyroxine level and goitre size were significantly associated with a relapse rate after a single dose of 131-I; larger goitres showed a trend towards high rates of relapse. Patients pretreated with propylthiouracil had a higher rate of relapse during the first year after radioactive iodine than those pretreated with carbimazole, but the difference was not significant when combined with other pretreatment variables.

CONCLUSIONS

A single fixed dose of radioactive iodine is a simple, safe, and effective treatment for hyperthyroidism. High basal free thyroxine concentration and large goitre size are associated with higher chance of relapse. Higher radioiodine doses may be considered to improve the cure rate.

Foreign body aspiration in Hong Kong Chinese children

OBJECTIVES

To describe and compare the demographic, clinical, radiological, and bronchoscopy features and outcomes of children with foreign body aspiration in early- and late-diagnosis groups, to report the reasons for delay in diagnoses, and to determine what objects are commonly aspirated.

DESIGN

Retrospective study.

SETTING

Department of Paediatrics, Queen Elizabeth Hospital, Hong Kong.

PATIENTS

All children younger than the age of 18 years with foreign body aspiration admitted to the study hospital from 1 January 1993 to 31 May 2006.

RESULTS

Sixteen (59%) of the patients were categorised into the early-diagnosis group (correctly diagnosed foreign body aspiration<7 days of symptom onset) and 11 (41%) into the late-diagnosis group (correctly diagnosed>or=7 days after symptom onset). The common clinical manifestations of foreign body aspiration were persistent cough (100%) and history of choking (74%). Most children (82%) in the late-diagnosis group and 25% in early-diagnosis group (P=0.004) were misdiagnosed as respiratory infections and asthma. Intrabronchial granulation was more common in the late-diagnosis group (13% vs 55%, P=0.033). Peanuts and watermelon seeds accounted for 85% of the aspirations; 63% of the foreign body aspirations occurred around the Chinese New Year festival.

CONCLUSION

Foreign body aspiration is difficult to diagnose in children. Misdiagnosis as asthma and respiratory infection can delay treatment and result in intrabronchial granuloma. We therefore suggest early bronchoscopy in suspicious cases. Parents should be cautious when giving peanuts and watermelon seeds to their children.

Bilateral femoral nerve compression and compartment syndrome resulting from influenza A-induced rhabdomyolysis: a case report

Bilateral femoral nerve compression neuropathy caused by primary iliopsoas muscle pathology is rare. We report a case of extensive compartment syndrome of the right arm and both legs associated with bilateral femoral nerve palsy resulting from severe muscle swelling secondary to influenza A infection. Our objective is to alert physicians to the possible development of compartment syndrome in patients with influenza and severe myalgia. We also reviewed the literature on the pathophysiology and management of femoral nerve compression neuropathy.

The contribution of mitochondrial dysfunction to a gene-environment model of Guamanian ALS and PD

Scientific investigations of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD) of Guam have implicated genetic and environmental risk factors in their etiology. Using brain tissue, we investigated mitochondrial dysfunction and report a higher frequency of somatic mutations in the light strand promoter (LSP) of the mitochondrial control region in Guam ALS and PD patients than in Guam controls, along with the presence of inherited mutations that may contribute to a novel gene-environment interaction risk model. Along with other risk factors, they demonstrate both the importance and significance of genetic and environmental contributions to Guam ALS and PD etiology.