Dengue Outbreak in Mombasa City,Kenya, 2013–2014: Entomologic Investigations

Dengue outbreaks were first reported in East Africa in the late 1970s to early 1980s including the 1982 outbreak on the Kenyan coast. In 2011, dengue outbreaks occurred in Mandera in northern Kenya and subsequently in Mombasa city along the Kenyan coast in 2013–2014. Following laboratory confirmation of dengue fever cases, an entomologic investigation was conducted to establish the mosquito species, and densities, causing the outbreak. Affected parts of the city were identified with the help of public health officials. Adult Ae. aegypti mosquitoes were collected using various tools, processed and screened for dengue virus (DENV) by cell culture and RT-PCR. All containers in every accessible house and compound within affected suburbs were inspected for immatures. A total of 2,065 Ae. aegypti adults were collected and 192 houses and 1,676 containers inspected. An overall house index of 22%, container index, 31.0% (indoor = 19; outdoor = 43) and Breteau index, 270.1, were observed, suggesting that the risk of dengue transmission was high. Overall, jerry cans were the most productive containers (18%), followed by drums (17%), buckets (16%), tires (14%) and tanks (10%). However, each site had specific most-productive container-types such as tanks (17%) in Kizingo; Drums in Nyali (30%) and Changamwe (33%), plastic basins (35%) in Nyali-B and plastic buckets (81%) in Ganjoni. We recommend that for effective control of the dengue vector in Mombasa city, all container types would be targeted. Measures would include proper covering of water storage containers and eliminating discarded containers outdoors through a public participatory environmental clean-up exercise. Providing reliable piped water to all households would minimize the need for water storage and reduce aquatic habitats. Isolation of DENV from male Ae. aegypti mosquitoes is a first observation in Kenya and provides further evidence that transovarial transmission may have a role in DENV circulation and/or maintenance in the environment.     

Dengue Virus 2 American-Asian Genotype Identified during the 2006/2007 Outbreak in Piauí, Brazil Reveals a Caribbean Route of Introduction and Dissemination of Dengue Virus in Brazil

Dengue virus (DENV) is the most widespread arthropod-borne virus, and the number and severity of outbreaks has increased worldwide in recent decades. Dengue is caused by DENV-1, DENV- 2, DENV-3 and DENV-4 which are genetically distant. The species has been subdivided into genotypes based on phylogenetic studies. DENV-2, which was isolated from dengue fever patients during an outbreak in Piaui, Brazil in 2006/2007 was analyzed by sequencing the envelope (E) gene. The results indicated a high similarity among the isolated viruses, as well as to other DENV-2 from Brazil, Central America and South America. A phylogenetic and phylogeographic analysis based on DENV-2E gene sequences revealed that these viruses are grouped together with viruses of the American-Asian genotype in two distinct lineages. Our results demonstrate the co-circulation of two American-Asian genotype lineages in northeast Brazil. Moreover, we reveal that DENV-2 lineage 2 was detected in Piauí before it disseminated to other Brazilian states and South American countries, indicating the existence of a new dissemination route that has not been previously described.     

Evaluation of the National Notifiable Diseases Surveillance System for Dengue Fever in Taiwan, 2010–2012

BackgroundIn Taiwan, around 1,500 cases of dengue fever are reported annually and incidence has been increasing over time. A national web-based Notifiable Diseases Surveillance System (NDSS) has been in operation since 1997 to monitor incidence and trends and support case and outbreak management. We present the findings of an evaluation of the NDSS to ascertain the extent to which dengue fever surveillance objectives are being achieved.MethodologyWe extracted the NDSS data on all laboratory-confirmed dengue fever cases reported during 1 January 2010 to 31 December 2012 to assess and describe key system attributes based on the Centers for Disease Control and Prevention surveillance evaluation guidelines. The system’s structure and processes were delineated and operational staff interviewed using a semi-structured questionnaire. Crude and age-adjusted incidence rates were calculated and key demographic variables were summarised to describe reporting activity. Data completeness and validity were described across several variables.Conclusions/SignificanceThe NDSS for dengue fever surveillance is a robust, well maintained and acceptable system that supports the collection of complete and valid data needed to achieve the surveillance objectives. The simplicity of the system engenders compliance leading to timely and accurate reporting. Completeness of hospitalization information could be further improved to allow assessment of severity of illness. To minimize misclassification, an algorithm to accurately classify travel cases should be established.     

Trends in cancer incidence in the Republic of Mauritius, 1991–2015

IntroductionMauritius, a small state, is among the few African countries where cancer registration is population based and nationwide. We reported trends in cancer incidence for twenty five years as well as the mortality to incidence ratio (MIR) as main quality indicator of the Mauritius National Cancer Registry (MNCR).Materials and methodsWe calculated age standardised incidence rates (ASRs) of cancers by sex and by 5 year age group for five successive year periods from 1991 to 2015. The average annual percentage change (AAPC) were determined by sex and cancer sites. MIRs were compared for the period 2001–2004 and 2012–2015.ResultsIn males, the most common cancer sites (in terms of ASRs per 100,000) were those of the colon-rectum (17.0), prostate (16.5), trachea-bronchus-lung (13.0), stomach (8.4) and lip-oral cavity-pharynx (7.7). The AAPC were +3.9%, +4.2%, +0.5%, -0.1% and -1.3% respectively. In females, the most frequent sites were breast (53.7), colon-rectum (13.2), cervix uteri (11.2), corpus uteri (7.7) and ovary (5.7). The AAPC were +3.4%, +4.4%, -2%, +5.2% and -0.1% respectively. The most significant decrease in MIRs among males were liver (1.9 to 1.0), stomach (1.3 to 0.8) and lung (1.7 to 1.2) cancers while among females, they were pancreas (3.4 to 1.3), liver (1.8 to 1.2) and stomach (1.5 to 0.8) cancers.ConclusionThe most common cancers were those associated with 'westernisation' of lifestyle. Our figures contrast with other Sub-Saharan Africa countries where infection related cancers are most predominant. The MNCR has also improved its data quality over time.     

Prospective Study of Chikungunya Virus Acute Infection in the Island of La Réunion during the 2005–2006 Outbreak

Background

Chikungunya virus (CHIKV) is a recently re-emerged arthropod borne virus responsible for a massive outbreak in the Indian Ocean and India, and extended to Southeast Asia as well as Italy. CHIKV has adapted to Aedes albopictus, an anthropophilic mosquito species widely distributed in Asia, Europe, Africa and America. Our objective was to determine the clinical and biological features of patients at the acute phase of CHIKV infection.

Methods and Findings

A prospective study enrolled 274 consecutive patients with febrile arthralgia recorded at the Emergency Department of the Groupe Hospitalier Sud-Réunion between March and May 2006. Three groups were defined: one group of 180 viremic patients (positive CHIKV RT-PCR), one group of 34 patients with acute post-viremic infection (negative CHIKV RT-PCR, positive anti-CHIKV IgM and negative IgG), and one group of 46 uninfected patients (negative CHIKV RT-PCR, anti-CHIKV IgM and IgG). Bivariate analyses of clinical and biological features between groups were performed. Patients with CHIKV viremia presented typically with asymmetrical bilateral polyarthralgia (96.5%) affecting the lower (98%) and small joints (74.8%), as well as asthenia (88.6%), headache (70%), digestive trouble (63.3%), myalgia (59%), exanthems (47.8%), conjunctival hyperhemia (23%) and adenopathy (8.9%). Vertigo, cutaneous dysesthesia, pharyngitis and haemorrhages were seldom observed. So far unreported symptoms such as chondrocostal arthralgia (20%), entesopathies (1.6%), talalgia (14%) were also noted. Prurit was less frequent during the viremic than post-viremic phase (13.9% vs. 41.2%; p<0.001), whereas lymphopenia was more frequent (87.6% vs. 39.4%; p<0.001). Others biological abnormalities included leukopenia (38.3%), thrombocytopenia (37.3%), increased ASAT and ALAT blood levels (31.6 and 7.3%, respectively) and hypocalcemia (38.7%). Lymphopenia <1,000/mm³ was very closely associated with viremic patients (Yule coefficient 0.82, positive predictive value 92.3%). Age under 65 was associated with a benign course, as no patients younger than 65 had to be hospitalized (Yule coefficient 0.78).

Conclusions

The diagnosis of CHIKV infection in acute phase is based on commonly accepted clinical criteria (fever and arthralgia), however clinical and biological diffrences exist in acute phase depending on whether or not the patient is within the viremic phase of the infection.     

Profile and Treatment Outcomes of Tuberculosis in the Elderly in Southeastern Nigeria, 2011–2012

Background

The demographic transition and increasing life expectancy in Africa has lead to a rising elderly population. In Nigeria, little is known about the profile of and treatment outcomes of tuberculosis (TB) in the elderly.

Methods

Retrospective cohort study of adult TB patients treated between January 2011 and December 2012 in two large health facilities in Nigeria. The demographic, clinical and treatment outcomes of patients aged 60 and older were compared with those aged 15 to 59 years.

Results

Elderly (≥60 years) TB patients accounted for 12.7% of all (1668) adult TB enrolled. Elderly patients had a higher proportion of men compared to non-elderly (64.2% vs 56.8%; p = 0.043); but a lower proportion of smear-positive TB at baseline (40.7% vs 65.8%; p<0.001). A higher proportion of elderly patients failed to smear convert after the intensive phase of treatment (23.7% vs 19.8%; p = 0.06), and overall elderly patients had lower treatment success rates (68.9% vs 77.1%; p = 0.009). Unsuccessful outcomes were mainly due to higher default and deaths in the elderly. The risk factors for unsuccessful outcomes in the elderly were: extrapulmonary TB case (adjusted odds ratio (aOR) 10.9; 95% confidence interval (CI) 1.1–108), and HIV co-infection (aOR 3.6; CI 1.1–11.7).

Conclusions

Treatment outcomes of elderly TB patients were inferior to non-elderly adults with higher death and default rates being implicated. With the rising elderly population, specific strategies are needed to quickly address TB management in the elderly in resource-limited settings.     

Quantifying food web interactions in the North Pacific – a data-based approach

As part of its annual bottom-trawl survey program, the Alaska Fisheries Science Center (AFSC) has been collecting and analyzing the stomach contents of groundfish predators since 1981. Between 1981 and 2011, a total of 233,451 fish stomachs were collected and analyzed from the eastern Bering Sea, the Gulf of Alaska, and the Aleutian Islands large marine ecosystems; these data are now available online as AFSC’s Groundfish Trophic Interactions Database. Here, we discuss features of the survey and data to aid in the interpretation and use of this extensive dataset for the Alaska region. The primary fish sampled include walleye pollock (Gadus chalcogrammus), Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and arrowtooth flounder (Atheresthes stomias), although 159 predator species have been included in the stomach content analysis. Prey length measurements are included for important commercial prey and can identify age or size classes of prey prior to their recruitment into fisheries and most other surveys. With these data, one can track time trends in growth, mortality, and prey composition as ecosystem indicators, and include food web interactions in fish stock assessments for ecosystem-based fisheries management.     

Epidemiology of Dengue Disease in the Philippines (2000–2011): A Systematic Literature Review

This literature analysis describes the available dengue epidemiology data in the Philippines between 2000 and 2011. Of 253 relevant data sources identified, 34, including additional epidemiology data provided by the National Epidemiology Center, Department of Health, Philippines, were reviewed. There were 14 publications in peer reviewed journals, and 17 surveillance reports/sources, which provided variable information from the passive reporting system and show broad trends in dengue incidence, including age group predominance and disease severity. The peer reviewed studies focused on clinical severity of cases, some revealed data on circulating serotypes and genotypes and on the seroepidemiology of dengue including incidence rates for infection and apparent disease. Gaps in the data were identified, and include the absence incidence rates stratified by age, dengue serotype and genotype distribution, disease severity data, sex distribution data, and seroprevalence data.

Protocol registration

PROSPERO CRD42012002292     

Radiation exposure and cancer incidence in a cohort of nuclear power industry workers in the Republic of Korea, 1992–2005

This study examines for the first time cancer incidence between radiation and non-radiation workers in nuclear power facilities in the Republic of Korea. Radiation workers were defined as persons who were issued with a dosimeter at nuclear power facilities, until 2005. All analyses were conducted on male workers only (in total 16,236 individuals) because of the sparseness of females. Statistical analyses were carried out using the standardized incidence ratio (SIR), to compare the cancer risks of radiation and non-radiation workers with those of the general population, and the χ² trend test was used to investigate any increase in cancer rates with dose. Poisson regression was also used to estimate the rate ratio (RR) and the excess relative risk (ERR) after considering the confounding effect due to smoking. During 1992–2005, 99 cancer cases in 63,503 person-years were observed among 8,429 radiation workers, while 104 cancer cases were observed in 48,301 person-years among 7,807 non-radiation workers. When compared with the site- and age-specific cancer rates for the male population of Korea, the SIR for all cancers combined was 1.07 [95% confidence interval (CI) 0.87–1.30] for radiation workers, and 0.88 (95% CI 0.72–1.06) for non-radiation workers, respectively. The RR for radiation workers compared with non-radiation workers was 1.18 (95% CI 0.89–1.58) for all cancers combined. The SIRs for thyroid cancer were noticeably high for both radiation and non-radiation workers, possibly due to the screening effect, but analysis of the RR showed that there was no statistically significant difference in thyroid cancer incidence rates between the two groups. For lung cancer, radiation workers showed a higher incidence rate as compared to non-radiation workers, with the RR being 3.48 (95% CI 1.19–11.48). A χ² trend test showed that there was no evidence for an increase in cancer rate with increasing cumulative dose for all cancers combined (p = 0.5108). The ERR per Sievert was estimated to be 1.69 (95% CI −2.07 to 8.21) for all cancers combined assuming a 10 years lag time. Consequently, a significant excess of cancer incidence among radiation workers in the nuclear power industry in Korea was not observed. Further follow-up and an expansion of the cohort are needed to overcome the lack of statistical power in the study.     

Dynamics of the horizontal structure of the tree stand in a pristine herb–bilberry forest of the subzone of the middle tiaga in the Komi Republic

According to observations from 1987 to 2010 on a constant sampling plot, using spatial statistics, we have shown dynamics of the horizontal structure of all-aged stands of a pristine spruce herb–bilberry forest. We note that the trees forming it provide a continual change of generations and, therefore, random community structure and its spatial stability. We determined that small-leaved arboreal plants, which represent part of the tree stand, tend to grouping at distances from 4 m. It was discovered that the mutual arrangement of trees of different sizes and species do not differ from a random occurrence.     

Michurinist Biology in the People’s Republic of China, 1948–1956

Michurinist biology was introduced to China in 1948; granted a state supported monopoly in 1952; and reduced to parity with western genetics from 1956. The Soviets exported it through the propaganda agencies Sino Soviet Friendship Association (SSFA) and VOKS (Cultural Relations with Foreign Countries). China’s Ministry of Agriculture achieved broad public awareness and acceptance of Michurinist biology through a translation, publication, and Soviet guest speakers campaign – all managed by a team of agriculturalists led by Luo Tianyu, a veteran CCP (Communist Party) cadre. The campaign grew exponentially, but did not affect university or Chinese Academy of Sciences biology. Luo Tianyu’s failed attempt to force Michurinist biology on a Beijing university triggered its second stage: monopoly status and a ban on “Mendelist-Morganist” biology in teaching, research, and publication. The CCP Central Committee supported this policy believing that Michurinst biology would increase agricultural production for the forthcoming first Five Year Plan; whereas, western genetics had no practical value. Michurinist biology flourished at all levels of education, research, and science literature; Western genetics was completely shut down. This only began to change when the CCP Central Committee became wary of China’s dependency on Soviet technical expertise and failure to fully utilize that of China. Change was further promoted by significant attacks on Michurinist biology by Soviet and East German biologists. Soon, these developments informed China’s “genetics question,” which became a test case for larger questions about the definition of science and the relationship between scientists and the state. Under the guidance of Lu Dingyi’s Central Committee Propaganda Department, the CCP eventually decided that, henceforth, science controversies would only be resolved by the science community; and that monopolies or ideological orthodoxies would not be imposed on science. At the same time, the CCP rescinded Michurinist biology’s monopoly and the ban on western genetics. By the mid-1960s western genetics had successfully restored itself, largely due to the leadership of C. C. Tan, a former student of Dobzhansky. Michurinist biology’s presence shrank and it became marginalized.     

Late Pleistocene–early Holocene transition recorded in the sediments of a former shallow lake in the Czech Republic

Quaternary limnic sediments from Velanská Cesta, a former lake in the Czech Republic, were investigated to document the response of an aquatic environment to global climatic shifts during the late Pleistocene–early Holocene transition. The obtained multi-proxy record, including subfossil diatoms, diatom-inferred variables (index of trophic state, halobic index, TP, and pH), plant macrofossils, and geochemical data, was compared with the δ¹⁸O GISP2 curve. Diatom accumulation zones and subzones established on the basis of a ConSLink cluster analysis corresponded well with the boundaries of the Bölling, Older Dryas, Alleröd, Younger Dryas, and Preboreal periods. The diatom-inferred trophic state and salinity data showed increased values during the colder epochs, which were supported by the findings of low-temperature macrofossil indicators in the corresponding samples. The results of this study document a long-term forcing of a shallow lacustrine ecosystem in central Europe by climatic events of a global scale.     

Fish–environment Associations in the Coastal Waters of Andros Island, The Bahamas

Synopsis We surveyed fish communities and corresponding environmental conditions at three broadly similar coastal sites of eastern Andros Island, The Bahamas over a summer–winter–summer sequence to assess the relationship between detailed environmental features and fish species patterns. Environmental variables included covers of various benthic flora components, benthic flora diversity, floral canopy height, micro-crustacean diversity and density, water temperature, extent of destructive land-use and extent of invasion by human-introduced exotic terrestrial plants. Correspondence analysis (CA) indicated that spatial (site) differences in environmental characteristics were greater than temporal (seasonal) differences. Detrended canonical correspondence analysis (DCCA) was used to assess the strength of relationships between the environmental characteristics and the distribution patterns of 25 fish species. Environmental features deemed to be most important in influencing fish species patterns included benthic flora canopy height, extent of invasion by exotic terrestrial plants, cover of Batophora oerstedii, cover of Thalassia testudinum, turf cover, water temperature, micro-crustacean diversity, and micro-crustacean density. Based upon similarities in distribution patterns, fish species formed four clusters which, ultimately, reflected similarities in species’ feeding habits and preferences for habitats that likely maximize foraging success. We conclude that fish distribution patterns are related to environmental characteristics, and that anthropogenic coastal activity, by influencing coastal benthic characteristics, may influence the distribution and abundances of fish species in coastal habitats.     

Spatio-Temporal Tracking and Phylodynamics of an Urban Dengue 3 Outbreak in S?o Paulo,Brazil

The dengue virus has a single-stranded positive-sense RNA genome of ∼10.700 nucleotides with a single open reading frame that encodes three structural (C, prM, and E) and seven nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins. It possesses four antigenically distinct serotypes (DENV 1–4). Many phylogenetic studies address particularities of the different serotypes using convenience samples that are not conducive to a spatio-temporal analysis in a single urban setting. We describe the pattern of spread of distinct lineages of DENV-3 circulating in São José do Rio Preto, Brazil, during 2006. Blood samples from patients presenting dengue-like symptoms were collected for DENV testing. We performed M-N-PCR using primers based on NS5 for virus detection and identification. The fragments were purified from PCR mixtures and sequenced. The positive dengue cases were geo-coded. To type the sequenced samples, 52 reference sequences were aligned. The dataset generated was used for iterative phylogenetic reconstruction with the maximum likelihood criterion. The best demographic model, the rate of growth, rate of evolutionary change, and Time to Most Recent Common Ancestor (TMRCA) were estimated. The basic reproductive rate during the epidemics was estimated. We obtained sequences from 82 patients among 174 blood samples. We were able to geo-code 46 sequences. The alignment generated a 399-nucleotide-long dataset with 134 taxa. The phylogenetic analysis indicated that all samples were of DENV-3 and related to strains circulating on the isle of Martinique in 2000–2001. Sixty DENV-3 from São José do Rio Preto formed a monophyletic group (lineage 1), closely related to the remaining 22 isolates (lineage 2). We assumed that these lineages appeared before 2006 in different occasions. By transforming the inferred exponential growth rates into the basic reproductive rate, we obtained values for lineage 1 of R₀ = 1.53 and values for lineage 2 of R₀ = 1.13. Under the exponential model, TMRCA of lineage 1 dated 1 year and lineage 2 dated 3.4 years before the last sampling. The possibility of inferring the spatio-temporal dynamics from genetic data has been generally little explored, and it may shed light on DENV circulation. The use of both geographic and temporally structured phylogenetic data provided a detailed view on the spread of at least two dengue viral strains in a populated urban area.     

Recent Epidemiological Trends of Dengue in the French Territories of the Americas (2000–2012): A Systematic Literature Review

Dengue is a public health concern across the globe, and an escalating problem in the Americas. As part of a wider programme (covering Latin America and South East Asia) to characterize the epidemiology of dengue in dengue endemic areas, we undertook a systematic literature review to assess epidemiological trends (incidence, timing and duration of outbreaks/epidemics, age and sex distribution, serotype distribution, seroprevalence and disease severity) for dengue across the French Territories of the Americas (FTA), in French Guiana, Guadeloupe, Martinique, Saint Martin and Saint Barthélemy between 2000 and 2012 (CRD42012002341: http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002341). Of 413 relevant data sources identified, 45 were eligible for inclusion. A large proportion of the available data were from national surveillance reports, and 12 publications were from peer-reviewed journals. During the review period, 3–5 epidemics were identified in each of the island territories and French Guiana, and epidemics were often associated with a shift in the predominant circulating dengue virus serotype. Substantial gaps in epidemiological knowledge were identified. In particular, information regarding dengue virus genotype distribution, seroprevalence and age distribution of dengue were lacking. Additionally, much of the available data were from epidemic years; data from inter-epidemic periods were sparse. Nevertheless, the available epidemiological data showed that dengue is endemic across the FTA and suggest an evolution towards hyperendemicity, highlighting the need to continue the efforts with the existing surveillance programmes to assist in planning an effective vaccination programme once a dengue vaccine is deployed.

Protocol registration

PROSPERO CRD42012002341