Control and Prevention of Anthrax, Texas, USA, 2019.

The zoonotic disease anthrax is endemic to most continents. It is a disease of herbivores that incidentally infects humans through contact with animals that are ill or have died from anthrax or through contact with Bacillus anthracis-contaminated byproducts. In the United States, human risk is primarily associated with handling carcasses of hoofstock that have died of anthrax; the primary risk for herbivores is ingestion of B. anthracis spores, which can persist in suitable alkaline soils in a corridor from Texas through Montana. The last known naturally occurring human case of cutaneous anthrax associated with livestock exposure in the United States was reported from South Dakota in 2002. Texas experienced an increase of animal cases in 2019 and consequently higher than usual human risk. We describe the animal outbreak that occurred in southwest Texas beginning in June 2019 and an associated human case. Primary prevention in humans is achieved through control of animal anthrax.

Anthrax Cases Associated with Animal-Hair Shaving Brushes.

During the First World War, anthrax cases in the United States and England increased greatly and seemed to be associated with use of new shaving brushes. Further investigation revealed that the source material and origin of shaving brushes had changed during the war. Cheap brushes of imported horsehair were being made to look like the preferred badger-hair brushes. Unfortunately, some of these brushes were not effectively disinfected and brought with them a nasty stowaway: Bacillus anthracis. A review of outbreak summaries, surveillance data, and case reports indicated that these cases originated from the use of ineffectively disinfected animal-hair shaving brushes. This historical information is relevant to current public health practice because renewed interest in vintage and animal-hair shaving brushes has been seen in popular culture. This information should help healthcare providers and public health officials answer questions on this topic.

Epidemiologic Investigation of Two Welder's Anthrax Cases Caused by Bacillus Cereus Group Bacteria: Occupational Link Established by Environmental Detection.

Abstract Bacillus cereus group bacteria containing the anthrax toxin genes can cause fatal anthrax pneumonia in welders. Two welder's anthrax cases identified in 2020 were investigated to determine the source of each patient's exposure. Environmental sampling was performed at locations where each patient had recent exposure to soil and dust. Samples were tested for the anthrax toxin genes by real-time PCR, and culture was performed on positive samples to identify whether any environmental isolates matched the patient's clinical isolate. A total of 185 environmental samples were collected in investigation A for patient A and 108 samples in investigation B for patient B. All samples from investigation B were real-time PCR-negative, but 14 (8%) samples from investigation A were positive, including 10 from patient A's worksite and 4 from his work-related clothing and gear. An isolate genetically matching the one recovered from patient A was successfully cultured from a worksite soil sample. All welder's anthrax cases should be investigated to determine the source of exposure, which may be linked to their worksite. Welding and metalworking employers should consider conducting a workplace hazard assessment and implementing controls to reduce the risk of occupationally associated illnesses including welder's anthrax.

Exposure to polychlorinated biphenyls and risk of neural-tube defects in a Mexican American population.

The authors examined the association between maternal polychlorinated biphenyl (PCB) levels and risk of neural tube defects (NTDs) in Mexican American women with NTD-affected pregnancies who resided in the 14 Texas-Mexico border counties during 1995-2000 (cases). Controls were randomly selected from study area women delivering normal live births. For PCB congeners with sufficient numbers of detectable values (PCB 99, 101, 110, 118, 138, 153, 180), there was little association between the proportions with detectable PCB levels in cases and controls. Odds ratios were <1 or compatible with the null, but power was low for some congeners. An index of seven PCB congeners (105, 118, 138, 153, 170, 180, 194) was also not associated with NTD risk. The maternal serum PCB levels in this study population (median PCB 153 level: 18 ng/g) were comparable to those with background exposure and do not appear to have contributed to the high prevalence of NTDs in this population.

An outbreak of foodborne botulism associated with food sold at a salvage store in Texas.

Foodborne botulism is caused by potent neurotoxins of Clostridium botulinum. We investigated a large outbreak of foodborne botulism among church supper attendees in Texas. We conducted a cohort study of attendees and investigated the salvage store that sold the implicated foods. We identified 15 cases of botulism (40%) among 38 church supper attendees. Nine patients (60%) had botulinum toxin type A detected in stool specimens. The diagnosis was delayed in 3 cases. Fifteen (63%) of 24 attendees who ate a chili dish developed botulism (relative risk, undefined; P<.001). The chili dish was prepared with "brand X" or "brand Y" frozen chili, "brand Z" canned chili, and hot dogs. An unopened container of brand X chili yielded type A toxin. Brand X chili was purchased at a salvage store where perishable foods were inadequately refrigerated. Our investigation highlights the need to improve clinicians' awareness of botulism. More rigorous and more unannounced inspections may be necessary to detect food mishandling at salvage stores.

Forty years of disinfectant failure: outbreak of postinjection Mycobacterium abscessus infection caused by contamination of benzalkonium chloride.

Benzalkonium chloride (BC) continues to be used as an antiseptic and contributes to serious outbreaks of disease. In July 1999, 6 postinjection joint infections caused by Mycobacterium abscessus were reported to the Texas Department of Health (Austin). We investigated this outbreak and identified 12 case patients who had been seen by the same physician and who had received an intra-articular or periarticular steroid injection during the period of 1 April through 31 July 1999. M. abscessus was cultured from either joint fluid or periarticular soft-tissue specimens obtained from 10 patients. We cultured environmental samples, and we compared isolates recovered from case patients with environmental isolates by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Four environmental samples containing diluted BC yielded M. abscessus. Clinical and environmental strains of M. abscessus were indistinguishable by RAPD-PCR. The case patients' strain was resistant to BC. The use of BC as an antiseptic should be discontinued.

Outbreak of Shiga toxin-producing Escherichia coli O111:H8 infections among attendees of a high school cheerleading camp.

Few US clinical laboratories screen stool specimens for Shiga toxin-producing Escherichia coli (STEC) other than E. coli O157. An outbreak of STEC O111:H8 infections indistinguishable from E. coli O157:H7 at a youth camp highlights the need to improve non-O157 STEC surveillance. Interviews of 521 (80%) of 650 attendees revealed 55 (11%) were ill; 2 developed hemolytic-uremic syndrome. Illness was associated with consuming salad during the camp's first lunch meal (hazard ratio [HR], 4.68; P<.01), consuming ice provided in barrels on the camp's final day (HR, 3.41; P<.01), eating cob corn (HR, 3.22; P<.01), and eating a dinner roll (HR, 2.82; P<.01). Cultures of 2 of 11 stools yielded E. coli O111:H8. Results of serologic testing and additional stool cultures demonstrated no evidence of infection with other bacterial pathogens, including E. coli O157, and supported infection with E. coli O111. Clinical laboratories should routinely screen suspect specimens for non-O157 STEC and should serotype and report Shiga-positive isolates.

Maternal serum B12 levels and risk for neural tube defects in a Texas-Mexico border population.

PURPOSE: Neural tube defects (NTDs) are common birth defects that can be prevented with folate fortification and supplementation. Studies suggest that other nutrients may also be essential to neural tube closure and have a potential role in risk reduction, with vitamin B(12) mentioned most often. We determined the effect of maternal serum B(12) levels, measured postpartum, on the risk of NTDs among a high risk Mexican American population. METHODS: The case-control study included 157 Mexican American women with NTD-affected pregnancies and 186 Mexican American women with normal pregnancies, who were residents of Texas-Mexico border counties and delivered during 1995 to 2000. RESULTS: Compared with women in the highest vitamin B(12) quintile, women in the lowest quintile showed a strong risk effect (odds ratio (OR) = 3.0, confidence interval (CI): 1.4, 6.3); while those in the 2nd and 3rd quintiles showed moderate risk effects (OR = 1.6, CI = 0.7, 3.6 and OR = 1.7, CI = 0.8, 3.8, respectively). Adjusting for obesity, vitamin supplements, dietary folate, dietary B(12), red blood cell folate, and other covariates did not materially change these estimates. CONCLUSIONS: Insufficient levels of serum B(12), which are not normally indicative of a classical vitamin B(12) deficiency nor stem from an inadequate diet, may be an important etiologic factor for NTDs in this population.

Fumonisin in tortillas produced in small-scale facilities and effect of traditional masa production methods on this mycotoxin.

Four small tortilla plants were visited in Cameron County, Texas, where observations were made on their production methods. Samples of liquids and solids were collected at each stage of the nixtamalization process, and the pH was recorded. Samples were analyzed for fumonisin B(1) (FB(1)) using an immunoaffinity column/HPLC method chosen for its sensitivity for FB(1). It was found that production methods were highly variable among the producers visited, with major differences particularly in the amount of lime added and boiling times. As reported by others working in Mexico and Central America, FB(1) was found in some tortillas. This led to studies of the effects of the various recipes and across a greater range of initial FB(1) concentration/damaged corn than has typically been reported. Five initial concentrations of FB(1) were tested using irradiated corn kernels inoculated with Fusarium verticillioides MRC 826 as the source of FB(1). The amount of FB(1) detected in the masa and tortillas decreased as the concentration of Ca(OH)(2) increased, and boiling time had no apparent effect. Unexpectedly, as the initial concentrations were increased in the corn prior to nixtamalization, greater percentage reductions in FB(1) were observed.

Blood folate levels on the Texas-Mexico border.

The Texas-Mexico border population has a high prevalence of neural tube defects (NTDs). In 1998, in an effort to reduce the risk of NTD-affected pregnancies, the US Food and Drug Administration mandated folic acid fortification of enriched grain products. Since then, the median serum folate and red blood cell (RBC) folate levels of US women aged 15 through 44 years has risen. During 1995 through 2000, serum and RBC folate levels of 170 Mexican American women residing on the Texas-Mexico border who had delivered live, normal infants within the previous 3 months were tested. The median serum folate levels rose 46%, and RBC folate levels rose 44%. The increase suggests that food fortification may be affecting folate levels among populations with economic and cultural barriers to consuming fortified foods. However, more data are needed before we can assess the impact of food fortification on NTD rates on the border.

Maternal exposures to cigarette smoke, alcohol, and street drugs and neural tube defect occurrence in offspring.

OBJECTIVES: Cigarettes, alcoholic beverages, and street drugs contain substances potentially toxic to the developing embryo. We investigated whether maternal cigarette smoking, secondhand smoke exposure, and alcohol or street drug use contributed to neural tube defect (NTD) occurrence in offspring. METHODS: We conducted a population-based case-control study among Mexican American women who were residents of the 14 Texas counties bordering Mexico. Case women had an NTD-affected pregnancy and delivered during 1995-2000. Control women were those who delivered live born infants in the same study area, without an apparent congenital malformation, randomly selected by year and facility. We interviewed women in person, 1-3 months postpartum, to solicit relevant information. RESULTS: Nonsmoking mothers exposed to secondhand smoke during the first trimester had an NTD odds ratio (OR) of 2.6 (95% confidence interval (CI)=1.6, 4.0) compared to those who neither smoked nor were exposed to secondhand smoke. Compared to the referent, the OR among women who smoked less than half a pack a day during the first trimester was 2.2 (95% CI=1.0, 4.8) and 3.4 (95% CI=1.2, 10.0) among those who smoked a half pack or more. Adjustment for maternal age, education, body mass index, and folate intake had a negligible effect on results. Alcohol and street drug use had no relation to NTD risk when adjusted for cigarette smoking. CONCLUSIONS: This study suggests that cigarette smoke including secondhand exposure is not only hazardous to the mother but may also interfere with neural tube closure in the developing embryo.

Implementation and outcomes of recommended folic acid supplementation in Mexican-American women with prior neural tube defect-affected pregnancies.

BACKGROUND: Upon discovering an NTD incidence rate of 27/10,000 in a Texas border county, the Texas Department of Health initiated folic acid intervention for prevention of recurrent NTDs in this predominantly Mexican-American population. This paper describes compliance of this population with USPHS folic acid recommendations and the impact of supplementation on pregnancy outcomes. METHODS: Based upon information from active surveillance, field teams personally contacted women having NTD-affected pregnancies to enroll them in FA intervention. Enrollees were provided FA at home visits at 3-month intervals throughout the project. RESULTS: Of 405 women identified with NTD-affected pregnancies, 299 (73.8%) enrolled in the intervention. One hundred ninety-three pregnancies occurred among 138 women. FA supplementation of 0.4 mg/day or more occurred during the last month preconception in 161 (83.4%) of the 193 pregnancies. No NTDs were detected in the 130 livebirths to women who received supplementation nor were NTDs detected in the 23 supplemented women who experienced pregnancy loss. CONCLUSIONS: Supplementation was successful in preventing recurrent NTDs in Mexican-American women.

Iron status indicators in women with prior neural tube defect-affected pregnancies.

OBJECTIVES: Iron deficiency is the most common nutrient deficiency in pregnant women and has been linked to negative impacts on the fetus. We describe the association of various iron-deficiency indices with risk of neural tube defect (NTD) among a high-risk Mexican-American population. METHODS: The study included 158 case-women (NTD-affected pregnancies) and 189 control-women (normal births) who were residents of the 14 Texas-Mexico border counties and delivered or terminated pregnancies during 1995-2000. In-person interviews and laboratory assays provided data. RESULTS: Case-women had higher odds of having minimal or no iron stores (serum ferritin <30 microg/L) compared to control-women (OR = 1.8, 95% CI = 1.0-3.3). The risk effect was not explained by low folate or B12 or other risk factors. CONCLUSION: Low serum ferritin may reflect the additive effect of multiple long-term factors, many of them related to poverty such as poor quality diet, lack of supplementation, and frequent pregnancies. Interpartum care is indicated in this population.

Maternal stress, social support, and risk of neural tube defects among Mexican Americans.

BACKGROUND: Studies suggest that maternal psychologic stress can increase the risk of congenital malformations, including neural tube defects (NTDs). We examined whether maternal stress and lack of social support contribute to NTD risk in a population living along the Texas-Mexico border. METHODS: Case mothers (N = 184) were Mexican-American women with NTD-affected pregnancies who delivered during 1995 to 2000 in one of the 14 Texas counties bordering on Mexico. Control mothers (N = 225) were randomly selected from Mexican-American women residing in the same area and delivering normal live births. We measured maternal stress by tallying the number of job changes, residential moves, and major injuries occurring during the year before conception. Social support was measured using social integration and perceived emotional support scales. RESULTS: Mothers who experienced one or more stressful life events during the year before conception had increased risks for NTDs (odds ratio [OR] = 2.9; 95% confidence interval [CI] = 1.8-4.7) compared with mothers experiencing no events. Mothers who scored low on emotional support had an elevated risk compared with those who scored high (OR = 4.6; CI = 2.2-9.7). Social support measures, such as network size and satisfaction, group interactions, and church attendance, were unrelated to NTD risk. The estimated effects were not modified or confounded by age, education, country of birth, income, obesity, vitamin supplements, dietary folate, cigarette smoking, or alcohol consumption. CONCLUSION: In this Mexican-American population, the occurrence of stressful life events was associated with NTD risk. These findings suggest that stress may exacerbate risk in populations with poor nutritional status and meager economic resources.

The effect of fever, febrile illnesses, and heat exposures on the risk of neural tube defects in a Texas-Mexico border population.

BACKGROUND: Hyperthermia produces neural tube defects (NTDs) in a variety of animal species. Elevated maternal body temperatures may also place the developing human embryo at risk. We examined the relation between maternal hyperthermia and the development of NTDs in a high-risk Mexican-American population. METHODS: Case-women were Mexican-American women with NTD-affected pregnancies who resided and delivered in any of the 14 Texas counties bordering Mexico, during 1995-2000. Control-women were randomly selected from study area residents delivering normal live births, frequency-matched to cases by hospital and year. Information on maternal fevers, febrile illnesses, exposures to heat generated from external sources, and hyperthermia-inducing activities was gathered through in-person interviews, conducted about six weeks postpartum. RESULTS: The risk effect (OR) associated with maternal fever in the first trimester, compared to no fever, was 2.9 (95% CI, 1.5-5.7). Women taking fever-reducing medications showed a lower risk effect (OR, 2.4; 95% CI, 1.0-5.6) than those who did not (OR, 3.8; 95% CI, 1.4-10.9). First-trimester maternal exposures to heat devices such as hot tubs, saunas, or electric blankets were associated with an OR of 3.6 (95% CI, 1.1-15.9). Small insignificant effects were observed for activities such as cooking in a hot kitchen (OR, 1.6; 95% CI, 1.0-2.6) and working or exercising in the sun (OR, 1.4; 95% CI, 0.9-2.2). CONCLUSIONS: Maternal hyperthermia increases the risk for NTD-affected offspring. Women intending to become pregnant should avoid intense heat exposures, carefully monitor and manage their febrile illnesses, and routinely consume folic acid supplements.

Diarrhea: a new risk factor for neural tube defects?

BACKGROUND: Neural tube defects (NTDs) affect approximately 4000 US pregnancies annually. Folic acid supplementation taken before conception protects against the occurrence of NTDs. Adequate levels of vitamin B12 also appear to play a significant role. Gastrointestinal disturbances, such as those caused by diarrhea, might negatively affect the availability of these vitamins, thereby increasing the risk of these birth defects. METHODS: To determine whether periconceptional diarrhea increases the risk of NTD-affected pregnancies, a population-based case-control study was conducted in the 14 Texas-Mexico border counties. Information on diarrhea and other risk factors was ascertained by in-person interview. Study subjects were Mexican-American women who resided and delivered in any border county during 1995-2000. Case women, identified through active surveillance, had liveborn or stillborn infants or fetuses diagnosed with anencephalus, spina bifida, or encephalocele. Control women were randomly selected from women delivering normal live births in study area health facilities. RESULTS: One or more episodes of periconceptional diarrhea were associated with increased risk of NTD-affected pregnancies compared to no episodes of diarrhea (OR = 3.7, 95% CI = 1.8-7.6). This association was independent of fever, obesity, maternal age, maternal birthplace, income, prior unproductive pregnancy, and dietary plus multivitamin folate intake, known risk factors for NTDs. CONCLUSIONS: Confirmation of this new risk factor might have public health implications due to the feasibility of modifying exposure.

Prevalence of craniorachischisis in a Texas-Mexico border population.

BACKGROUND: The most severe neural tube defect (NTD), craniorachischisis, is characterized by anencephaly confluent with spina bifida open from the cervical to the lumbar region. We describe the prevalence of craniorachischisis among the Texas-Mexico border population during the period 1993-1999. METHODS: An active surveillance system identified all clinically apparent NTD-affected fetuses and infants born to mothers residing and delivering in any of the 14 Texas-Mexico border counties. Craniorachischisis cases included live-born, stillborn, and therapeutic abortions. RESULTS: A total of 16 craniorachischisis cases were identified for a total prevalence of 0.51 per 10,000 live births (Mexican American prevalence, 0.52 per 10,000) and a prevalence of 0.28 per 10,000 live births for cases of 20 weeks gestation or greater. CONCLUSIONS: The prevalence of craniorachischisis was higher than that reported in Atlanta (0.1 per 10,000 live births), but much lower than that reported in Northern China (10.7 per 10,000 births). In this high NTD prevalence region, it is possible that a multiplicity of risk factors, mostly related to poverty, contribute to a high prevalence of craniorachischisis.

Homocysteine remethylation enzyme polymorphisms and increased risks for neural tube defects.

Folic acid supplementation can effectively reduce the risk of neural tube defects (NTDs); however, the mechanism underlying this beneficial effect remains unclear. Recent evidence suggests that certain folate pathway genes, as well as those related to homocysteine metabolism might be contributing to this effect. The purpose of this study is to investigate whether gene polymorphisms of methionine synthase (MTR) and methionine synthase reductase (MTRR) are involved in the risk for NTDs, specifically spina bifida. We detected MTR A2756G and MTRR A66G polymorphisms using PCR-RFLP analysis in a group of NTD infants, their mothers and normal controls. We found that infants with the MTRR mutant genotype had a 2.6-fold higher risk of NTDs when compared to the AA genotype (OR = 2.6, 95%CI = 1.3-5.3). Mothers with the MTRR mutant genotype also had a 1.9-fold higher risk of having an NTD baby compared to AA genotype (OR = 1.9, 95%CI = 1.1-3.1). Infants who carry mutant alleles for both MTRR and MTR had exceptionally elevated NTD risks, with odds ratios of 5.1 compared to infants with the wild type genotype at both loci (AA + AA) (OR = 5.1, 95%CI = 1.7-15.4). A comparable result was observed in the mothers of NTD cases (OR = 2.1, 95%CI = 1.0-4.7). Our results indicate that MTRR and MTR genes may interact to increase the infants' NTD risks. These results did not appear to be influenced by maternal periconceptional folic acid intake. However,the sample size of this study was limited, and a larger population study is needed to pursue these initial observations.