Maria Renee Lopez

Surveillance methods that permit rapid detection of circulating pathogens in low-resource settings are desperately needed. In this study, we evaluated a mosquito bloodmeal-based surveillance method (“xenosurveillance”) in rural Guatemala. Twenty households from two villages (Los Encuentros and Chiquirines) in rural southwest Guatemala were enrolled and underwent weekly prospective surveillance from August 2019 to December 2019 (16 weeks). When febrile illness was reported in a household, recently blood-fed mosquitoes were collected from within dwellings and blood samples taken from each member of the household. Mosquitoes were identified to species and blood sources identified by sequencing. Shotgun metagenomic sequencing was used to identify circulating viruses. Culex pipiens (60.9%) and Aedes aegypti (18.6%) were the most abundant mosquitoes collected. Bloodmeal sources were most commonly human (32.6%) and chicken (31.6%), with various other mammal and avian hosts detected. Several mosquito-specific viruses were detected, including Culex orthophasma virus. Human pathogens were not detected. Therefore, xenosurveillance may require more intensive sampling to detect human pathogens in Guatemala and ecologically similar localities in Central America.

Public market workers may be disproportionally exposed to SARS-CoV-2 due to interactions with shoppers. We aimed to estimate the seroprevalence of SARS-CoV-2 and determine whether occupation or adherence to preventive practices were associated with exposure. From July to December 2021, we longitudinally surveyed two Guatemalan markets twice. We collected blood to detect anti-S IgA, anti-S IgG, and anti-N IgG using ELISA, and a nasopharyngeal swab to detect SARS-CoV-2 using rRT-PCR. We estimated seroprevalences and assessed associations using generalized estimating equations. Of 229 workers, 109 (48%) participated in the first survey and 87 (38%) in the second. At baseline, 77% were female, 64% were aged <40, and 81% were vendors. Overall, the seroprevalence increased between surveys (61% to 89% for anti-S IgA, 53% to 91% for anti-S IgG, and 22% to 29% for anti-N IgG), but the magnitude differed by vaccination status and antibody type. The prevalence of infections decreased from 13% to 1% and most were asymptomatic. Vendor occupation was associated with IgA and IgG anti-S in males but not females. Using a mask was a protective measure. Most market workers had been exposed to SARS-CoV-2, possibly through asymptomatic individuals. Masking is a protective measure to be prioritized during high transmission.

Despite offering free-of-charge COVID-19 vaccines starting July 2021, Guatemala has one of the lowest vaccination rates in Latin America. From 28 September 2021 to 11 April 2022, we conducted a cross-sectional survey of community members, adapting a CDC questionnaire to evaluate COVID-19 vaccine access and hesitancy. Of 233 participants ≥ 12 years, 127 (55%) received ≥1 dose of COVID-19 and 4 (2%) reported prior COVID-19 illness. Persons ≥ 12 years old who were unvaccinated (n = 106) were more likely to be female (73% vs. 41%, p < 0.001) and homemakers (69% vs. 24%, p < 0.01) compared with vaccinated participants (n = 127). Among those ≥18 years, the main reported motivation for vaccination among vaccinated participants was to protect the health of family/friends (101/117, 86%); on the other hand, 40 (55%) unvaccinated persons reported little/no confidence in public health institutions recommending COVID-19 vaccination. Community- and/or home-based vaccination programs, including vaccination of families through the workplace, may better reach female homemakers and reduce inequities and hesitancy.

Despite offering free-of-charge COVID-19 vaccines starting July 2021, Guatemala has one of the lowest vaccination rates in Latin America. During September 28, 2021 to April 11, 2022, we conducted a cross-sectional survey of community members adapting a CDC questionnaire to evaluate COVID-19 vaccine access and hesitancy. Of 233 participants ≥12 years, 127 (55%) received >1 dose of COVID-19 and 4 (2%) reported prior COVID-19 illness. Persons ≥12 years old unvaccinated (n=106) were more likely to be female (73% vs 41%, p<0.001) and homemakers (69% vs 24%, p<0.01) compared with vaccinated participants (n=127). Among those ≥18 years, the main reported motivation for vaccination among vaccinated participants was to protect the health of family/friends (101/117, 86%); 40 (55%) unvaccinated persons reported little/no confidence in public health institutions recommending COVID-19 vaccination. Community- and/or home-based vaccination programs, including vaccination of families through the workplace, may better reach female homemakers and reduce inequities and hesitancy.

: Although Central America is largely dengue virus (DENV)-endemic, the 2015–2016 Zika virus (ZIKV) pandemic brought new urgency to develop surveillance approaches capable of characterizing the rapidly changing disease burden in resource-limited settings. We conducted a pediatric DENV surveillance study in rural Guatemala, including serial cross-sectional surveys from April through September 2015 (Survey 1), in October–November 2015 (Survey 2), and January–February 2016 (Survey 3). Serum underwent DENV IgM MAC ELISA and polymerase chain reaction testing. Using banked specimens from Surveys 2 and 3, we expanded testing to include DENV 1–4 and ZIKV microneutralization (MN₅₀), DENV NS1 IgG ELISA, and ZIKV anti-NS1 antibody Blockage of Binding (BoB) ELISA testing. Demographic risk factors for ZIKV BoB positivity were explored using multivariable generalized linear regression models. Of Survey 2 and 3 samples available (N = 382), DENV seroprevalence slightly increased (+1%–10% depending on the assay) during the surveillance period and increased with age. In contrast, ZIKV seroprevalence consistently increased over the 3-month period, including from 6% to 34% (P < 0.0001) and 10%–37% (P < 0.0001) using the MN₅₀ ≥100 and BoB ELISA assays, respectively. Independent risk factors for ZIKV seropositivity included older age (prevalence ratio (PR)/year = 1.12, 95% confidence interval (CI) = 1.07–1.17) and primary caregiver literacy (PR = 2.80, CI = 1.30–6.06). Rapid active surveillance (RAS) surveys demonstrated a nearly 30% increase in ZIKV prevalence and a slight (≤ 10%) increase in DENV seroprevalence from October to November 2015 to January to February 2016 in rural southwest Guatemala, regardless of serologic assay used. RAS surveys may be a useful “off-the-shelf” tool to characterize arboviruses and other emerging pathogens rapidly in resource-limited settings.

Background: Diarrhea is a major cause of morbidity and mortality, yet incidence and etiology data are limited. We conducted laboratory-based diarrhea surveillance in Guatemala. Methods: A diarrhea case was defined as ≥3 loose stools in a 24-h period in a person presenting to the surveillance facilities. Epidemiologic data and stool specimens were collected. Specimens were tested for bacterial, parasitic, and viral pathogens. Yearly incidence was adjusted for healthcare seeking behaviors determined from a household survey conducted in the surveillance catchment area. Results: From November 2008 to December 2012, the surveillance system captured 5331 diarrhea cases; among these 1381 (26%) had specimens tested for all enteric pathogens of interest. The adjusted incidence averaged 659 diarrhea cases per 10,000 persons per year, and was highest among children aged < 5 years, averaging 1584 cases per 10,000 children per year. Among 1381 (26%) specimens tested for all the pathogens of interest, 235 (17%) had a viral etiology, 275 (20%) had a bacterial, 50 (4%) had parasites, and 86 (6%) had co-infections. Among 827 (60%) specimens from children aged < 5 years, a virus was identified in 196 (23%) patients; 165 (20%) had norovirus and 99 (12%) rotavirus, including co-infections. Among 554 patients aged ≥5 years, 103 (19%) had a bacterial etiology, including diarrheagenic Escherichia coli in 94 (17%) cases, Shigella spp. in 31 (6%), Campylobacter spp. in 5 (1%), and Salmonella spp. in 4 (1%) cases. Detection of Giardia and Cryptosporidium was infrequent (73 cases; 5%). Conclusions: There was a substantial burden of viral and bacterial diarrheal diseases in Guatemala, highlighting the importance of strengthening laboratory capacity for rapid detection and control and for evaluation of public health interventions.

Influenza is a major cause of respiratory illness resulting in 3–5 million severe cases and 291,243-645,832 deaths annually. Substantial health and financial burden may be averted by annual influenza vaccine application, especially for high risk groups. We used an active facility-based surveillance platform for acute respiratory diseases in three hospitals in Guatemala, Central America, to estimate the incidence of laboratory-confirmed hospitalized influenza cases and identify risk factors associated with severe disease (defined as admission to the intensive care unit (ICU) or death). We enrolled patients presenting with signs and symptoms of acute respiratory infection (ARI) and obtained naso- and oropharyngeal samples for real-time reverse transcriptase polymerase chain reaction (RT-PCR). We used multivariable logistic regression to identify risk factors for ICU admission or death, adjusted for age and sex. From May 2008 to July 2012, among 6326 hospitalized ARI cases, 446 (7%) were positive for influenza: of those, 362 (81%) had influenza A and 84 (18%) had influenza B. Fifty nine percent of patients were aged ≤ 5 years, and 10% were aged ≥ 65 years. The median length of hospitalization was 5 days (interquartile range: 5). Eighty of 446 (18%) were admitted to the ICU and 28 (6%) died. Among the 28 deaths, 7% were aged ≤ 6 months, 39% 7–60 months, 21% 5–50 years, and 32% ≥ 50 years. Children aged ≤ 6 months comprised 19% of cases and 22% of ICU admissions. Women of child-bearing age comprised 6% of cases (2 admitted to ICU; 1 death). In multivariable analyses, Santa Rosa site (adjusted odds ratio [aOR] = 10, 95% confidence interval [CI] = 2–50), indigenous ethnicity (aOR = 4, 95% CI = 2–13, and radiologically-confirmed pneumonia (aOR = 5, 95% CI = 3–11) were independently associated with severe disease. Adjusted for hospital utilization rate, annual incidence of hospitalized laboratory-confirmed influenza was 24/100,000 overall, 93/100,000 for children aged < 5 years and 50/100,000 for those ≥ 65 years. Influenza is a major contributor of hospitalization and death due to respiratory diseases in Guatemala. Further application of proven influenza prevention and treatment strategies is warranted.

Acute respiratory infection (ARI) is an important cause of mortality in children and adults. However, studies assessing risk factors for ARI-related deaths in low- and middle-income settings are limited. We describe ARI-related death and associated factors among children aged < 2 years and adults aged ≥18 years hospitalized with ARI in Guatemala. We used respiratory illness surveillance data in Guatemala from 2007 to 2013. ARI was defined as evidence of acute infection and ≥ 1 sign/symptom of respiratory disease in hospitalized patients. Clinical, sociodemographic, and follow-up data were gathered. Nasopharyngeal/oropharyngeal swabs were collected from patients with ARI and tested for 6 respiratory viruses; urine was collected only from adults with ARI and tested for pneumococcal antigen. Blood cultures and chest radiographs were performed at the physician’s discretion. Radiographs were interpreted per World Health Organization guidelines to classify endpoint pneumonia (i.e. suggestive of bacterial pneumonia). Multivariable logistic regression was used to compare characteristics of patients with fatal cases, including those who died in-hospital or were discharged in a moribund state, with those of patients with non-fatal cases. Among 4109 ARI cases identified in hospitalized children < 2 years old, 174 (4%) were fatal. Median age at admission was 4 and 6 months for children with fatal and non-fatal cases, respectively. Factors associated with fatality included low weight-for-age, low family income, heart disease, and endpoint pneumonia; breastfeeding and respiratory syncytial virus (RSV) detection were negatively associated with fatality. Among 1517 ARI cases identified in hospitalized adults ≥18 years, 181 (12%) episodes were fatal. Median age at admission was 57 years for adults with fatal and non-fatal cases. Low body mass index, male sex, kidney disease, and endpoint pneumonia were significantly more common among patients with fatal versus non-fatal cases. Our findings highlight some of the factors that must be addressed in order to reduce ARI-related mortality, including promotion of good nutrition, breastfeeding, management and prevention of chronic comorbidities, and poverty reduction. Although no specific pathogen increased risk for death, endpoint pneumonia was significantly associated with fatality, suggesting that the pneumococcal conjugate vaccine could contribute to future reductions in ARI-related mortality.

We examined burden and factors associated with norovirus (NoV) acute gastroenteritis (AGE) among children in rural Guatemala. Children age 6 weeks to 17 years were enrolled into three AGE surveillance groups, using two-stage cluster sampling: a prospective participatory syndromic surveillance (PSS) cohort and two cross-sectional rapid active sampling (RAS) surveys, conducted from April 2015 to February 2016. Epidemiologic and NoV testing data were used to identify factors associated with NoV infection, AGE, and NoV+ AGE. The three cross-sectional surveys (PSS enrollment visit, RAS Survey 1, and RAS Survey 2) enrolled 1,239 children, who reported 134 (11%) AGE cases, with 20% of AGE and 11% of non-AGE samples positive for NoV. Adjusted analyses identified several modifiable factors associated with AGE and NoV infection. The cross-sectional RAS surveys were practical and cost-effective in identifying population-level risk factors for AGE and NoV, supporting their use as a tool to direct limited public health resources toward high-risk populations.