Dengue Hemorrhagic Fever in the Northwest of Mexico: A Two-Decade Analysis.

BACKGROUND: In Baja California Sur, Mexico, there are no records of dengue hemorrhagic fever in the state before 1995. Until now, there have been no published reports on the incidence rate. OBJECTIVE: To assess the incidence rate of dengue hemorrhagic fever in Baja California Sur in the last two decades. METHODS: We analyzed data on the total number of cases in the general population, incidence rate, age groups, gender, serotypes, and mortality data. RESULTS: There were epidemiological outbreaks in 2003, 2006, 2010, 2013, and 2014. The year with the highest number of registered cases was 2003 (441 cases), with the highest incidence rate of 92.52/100,000. The age groups that were primarily affected were 15-24 and 45-64 years. The serotypes of dengue virus registered during those years were DENV-1 and DENV-2. CONCLUSIONS: Dengue hemorrhagic fever in Baja California Sur has had cyclic patterns of occurrence in the last 20 years. Since 2003, the incidence rate of dengue hemorrhagic fever has greatly decreased.

Decades of Experience in the Diagnosis of Dengue Fever in the Northwest of Mexico.

BACKGROUND: The State of Baja California Sur is in an arid region of Mexico, the southern half of the Baja California Peninsula. Given its aridity and physical isolation from mainland Mexico, there were no records of dengue fever in the state before 1985. Until now, no data on dengue incidence had been published. OBJECTIVE: To study some epidemiological features of dengue fever in Baja California Sur, Mexico in the last 30 years. METHODS: Total number of cases, general population, sex, age groups, serotypes, mortality, and incidence data were analyzed. RESULTS: There was a 652% increase in reported cases from 2012 through 2014. Age groups mostly affected were adults aged 15-24 and 45-64 years old. CONCLUSIONS: This study makes a thorough analysis of the incidence of dengue and makes recommendations to face the epidemiological challenge.

Genome sequence analysis of the Vibrio parahaemolyticus lytic bacteriophage VPMS1.

VPMS1 is a Vibrio parahaemolyticus lytic phage isolated from a marine clam. The 42.3-kb genome was predicted to encode 53 proteins. Comparison of the VPMS1 DNA genome with known phage genomes revealed no similarity; hence, it represents a new VP phage, organized into three differently oriented modules. The module for packaging covers 12 % of the genome, the module for structure covers 31 %, and the module for replication and regulation covers 48 %. The G + C content was 44.67 %. The coding region corresponds to 91 % of the genome, and 9 % apparently does not encode any protein. Thirty genes, constituting 57 % of the genome, had significant similarity to some reported proteins in the protein database; 23 genes, constituting 43 % of the genome, showed no significant homology to any reported protein, and these could be new proteins whose hypothetical functions can be deduced from their position in the genome.

Mortality trend by dengue in Mexico 1980 to 2009.

OBJECTIVE: To describe the mortality of dengue in Mexico during 1980 to 2009. MATERIAL AND METHODS: Dengue mortality data for Mexico were obtained from Instituto Nacional de Estadistica, Geografía e Informática. We used standardized and non-standardized dengue mortality rates per 1,000,000 people and determined the mortality trend. The groups were based on International Classification of Diseases coding criteria (ICD-9 E061 and ICD-10 A91X). The results were stratified by age groups and the frequencies of dengue deaths were compared using relative risk (RR) with its 95% confidence interval. RESULTS: During 1980 to 2009 in Mexico, 549 deaths due to dengue were reported. We found an important variation in the mortality rates during the years studied. We were able to identify three periods: 1980 to 1992, 1994 to 2000, and 2001 to 2009. The mortality rates found are from 0.88/1,000,000 through 0.00/1,000,000. The average mortality rates by decade: 1980 to 1989: 0.53/1,000,000; 1990 to 1999: 0.06/1,000,000; 2000 to 2009: 0.12/1,000,000. In the analysis of mortality by community size during 2000 to 2009, we observed in the small communities with < 2,499 people, the risk is 1.25 times higher than in those with more than 20,000 people. CONCLUSIONS: We found, in general, a sustained decline in the number of deaths by dengue over the last 30 years in Mexico. However, a slow increase was observed since 1994, which may be related to the circulation of DENV2 and DENV3, among other factors. We need to strengthen prevention programs in smaller communities (< 2,499) where we found a higher risk of mortality due to dengue.

A study of DNA damage in buccal cells of consumers of well- and/or tap-water using the comet assay: Assessment of occupational exposure to genotoxicants.

Because of concerns that natural aquifers in the region of Todos Santos (Baja California Sur, Mexico) might be contaminated by organochlorine pesticides and heavy metals, a case-control study was conducted among consumers and non-consumers of well- and/or tap-water to determine risks to human health. This study was based on a genotoxic evaluation of buccal cells using the Comet assay technique. Levels of DNA damage in the consumers group were significantly higher than those of the control group. However, occupational exposure to genotoxicants showed to be the critical factor rather than water consumption. Taking into account the professions of well- and/or tap-water consumers, agricultural workers exposed directly (those who fumigated) or indirectly (those not involved in fumigating) to agrochemicals showed greater genetic damage than controls. This difference persisted even when age, and whether the person smoked or consumed alcoholic drinks were considered. These factors were not associated with the level of genetic damage observed. Chemical analyses of organochlorine pesticides and heavy metals were carried out to evaluate the water quality of wells, faucets, and surface water of canals consumed by the population and/or used for irrigation. High concentrations of α and ß endosulfan were detected in water of surface canals. Although our inventory of agrochemicals employed in the region showed the use of products considered carcinogenic and/or mutagenic, they were not detected by the analytical techniques used. Heavy metals (arsenic, mercury, and lead) were detected in water of some wells used for irrigation and human consumption. Environ. Mol. Mutagen. 58:619-627, 2017. © 2017 Wiley Periodicals, Inc.

Environmental impacts of two kind of ponds for shrimp production at Northwest Mexico.

Aquaculture offers a major opportunity for the economic development of Baja California Sur (BCS), Mexico. The severely limited freshwater supply and the geographic isolation of the state place limits on other productive activities. Despite the aridity, the natural vegetation of BCS is diverse and structurally complex with a high percentage (20%) of endemic species. In this work we compare the environmental impacts produced by two kinds of aquaculture systems: coastal ponds vs. inland ponds. Construction and operation of coastal ponds does not require destruction of the natural vegetation and, as is true for inland ponds. Coastal ponds are also compatible with conservation of mangroves, sea grasses and sensitive habitats for fish and mollusks. To reduce the negative impacts of aquaculture and to protect the vegetation of Baja California Sur, we recommend the use of coastal ponds for shrimp production.

Differential expression of proteins in the midgut of Anopheles albimanus infected with Plasmodium berghei.

The main vector for transmission of malaria in Mexico is the Anopheles albimanus mosquito. The midgut of disease-transmitting mosquitoes carries out a variety of functions that are related to blood feeding. We analyzed the midgut of A. albimanus infected with Plasmodium berghei (resistant mosquito) using a proteomic approach to identify putative short peptides that are enriched in the midgut after blood feeding. Mosquito midguts were analyzed by two-dimensional electrophoresis to determine the changes in protein profiles. We identified 21 spot proteins that are differentially expressed in the blood of mosquitoes during the immune challenge. Molecular weight of the spots varied from 13 to 36 kDa, with a broad isoelectric point range of 3.92-8.90. We identified the differentially expressed proteins using mass spectrometry and constructed a proteomic data base of the A. albimanus midgut with diverse functions, some of them proteins with digestive and immunologic functions. Identification of these proteins may have important implications for understanding the blood meal digestion process, as well as developing novel vector control strategies and understanding parasite vector interactions.

Yolk proteins during ovary and egg development of mature female freshwater crayfish (Cherax quadricarinatus).

Vitellins from ovaries and eggs at different stages of development in freshwater crayfish (Cherax quadricarinatus) were examined by chromatography, PAGE and SDS-PAGE. With these methods, two forms of vitellin (Vt1 and Vt2) were observed in ovaries and eggs (stages I and V). In ovaries in secondary vitellogenesis, native molecular mass was 470 (Vt1) and 440 (Vt2) kDa. The electrophoretic pattern of the eggs proved to be more complex. The protein molecular mass depend on the development stage of the egg: stage I, 650 kDa (Vt1) and 440 kDa (Vt2); stage V, 390 kDa (Vt1) and 340 kDa (Vt2). The identified vitellins appear to be lipo-glycocarotenoprotein. A similar vitellin polypeptide composition was observed in the two forms of vitellin from ovaries and eggs in stage V. In ovaries the SDS-PAGE analysis showed four subunits with molecular weights of approximately 180, 120, 95 and 80 kDa (Vt1 and Vt2). The polypeptide composition in the two forms of vitellins in stage I and stage III eggs were different at 195, 190, 130 and 110 kDa (Vt1) and 116 and 107 kDa (Vt2). On the other hand, in stage V eggs, 110, 95, 87 and 75 kDa (Vt1 and Vt2) were identified. Two antibodies (Ab1 and Ab2) were prepared against the purified proteins of stage V eggs and their specificity was demonstrated by radial immunoprecipitation, and Western blotting analysis. Two forms of vitellins were also found in stage V eggs after chromatography on Sepharose CL-2B column and hydroxylapatite and polyacrylamide gel electrophoresis.

Vitellogenin mRNA expression in Cherax quadricarinatus during secondary vitellogenic at first maturation females.

PCR products of 1.1 and 0.9 kb were generated using Cherax quadricarinatus genomic DNA in the first case, and hepatopancreas and ovary cDNAs in the second case. These PCR products were cloned and analyzed for nucleotide sequences. The 1.1 kb fragment was used as a probe for Northern hybridization, revealing a transcript of approximately 8 kb in both tissues. Results from both Northern blot and RT-PCR analyses showed that the mRNA enconding the 3' end of the vitellogenin cDNA was present simultaneously in both hepatopancreas and ovary tissues in secondary vitellogenic at first maturation females, but was not detected in male hepatopancreas. The deduced amino acid sequences of Vitellogenin (Vg) cDNAs from ovary and hepatopancreas confirmed the existence at least two different Vg genes, and two different sites of synthesis.