The association between Zika virus infection and microcephaly in Brazil 2015-2017: An observational analysis of over 4 million births.

BACKGROUND: In 2015, high rates of microcephaly were reported in Northeast Brazil following the first South American Zika virus (ZIKV) outbreak. Reported microcephaly rates in other Zika-affected areas were significantly lower, suggesting alternate causes or the involvement of arboviral cofactors in exacerbating microcephaly rates. METHODS AND FINDINGS: We merged data from multiple national reporting databases in Brazil to estimate exposure to 9 known or hypothesized causes of microcephaly for every pregnancy nationwide since the beginning of the ZIKV outbreak; this generated between 3.6 and 5.4 million cases (depending on analysis) over the time period 1 January 2015-23 May 2017. The association between ZIKV and microcephaly was statistically tested against models with alternative causes or with effect modifiers. We found no evidence for alternative non-ZIKV causes of the 2015-2017 microcephaly outbreak, nor that concurrent exposure to arbovirus infection or vaccination modified risk. We estimate an absolute risk of microcephaly of 40.8 (95% CI 34.2-49.3) per 10,000 births and a relative risk of 16.8 (95% CI 3.2-369.1) given ZIKV infection in the first or second trimester of pregnancy; however, because ZIKV infection rates were highly variable, most pregnant women in Brazil during the ZIKV outbreak will have been subject to lower risk levels. Statistically significant associations of ZIKV with other birth defects were also detected, but at lower relative risks than that of microcephaly (relative risk < 1.5). Our analysis was limited by missing data prior to the establishment of nationwide ZIKV surveillance, and its findings may be affected by unmeasured confounding causes of microcephaly not available in routinely collected surveillance data. CONCLUSIONS: This study strengthens the evidence that congenital ZIKV infection, particularly in the first 2 trimesters of pregnancy, is associated with microcephaly and less frequently with other birth defects. The finding of no alternative causes for geographic differences in microcephaly rate leads us to hypothesize that the Northeast region was disproportionately affected by this Zika outbreak, with 94% of an estimated 8.5 million total cases occurring in this region, suggesting a need for seroprevalence surveys to determine the underlying reason.

Outbreak of beriberi in an Indian population of the upper Amazon region, Roraima State, Brazil, 2008.

Edema, parasthesias, and paresis affected 10 residents of an Indian community in Roraima state; three died. Mining with mercury occurs locally; caxirí, a traditional alcoholic drink, is consumed daily. We conducted a 1:2 unmatched case-control study; a case was an Indian from Uiramutã county (population of 9,127) who presented ≥ 1 of lower extremity edema, paresthesias, paresis, or weakness. Controls were asymptomatic Indians randomly selected from the population. We identified 90 cases (prevalence of 1%) and 180 controls; all were enrolled. Among cases, 79% were male, and the median age was 31 years. Ethnicity was Macuxí, and 49% had income. Cases had lower extremity edema (85%), upper extremity paresthesias (84%), and lower extremity weakness and pain (78%). Risk factors were male sex (odds ratio [OR] = 6.8; P < 0.001), age 31-40 years (OR = 5.63; P < 0.001), and consumption of caxirí (OR = 2.7; P < 0.003). Mercury exposure was not a risk. Thiamine therapy produced complete rapid clinical recovery in all cases, confirming the diagnosis of beriberi. We recommend surveillance, thiamine supplementation, and nutritional intervention.

Oral transmission of Chagas disease by consumption of açaí palm fruit, Brazil.

In 2006, a total of 178 cases of acute Chagas disease were reported from the Amazonian state of Pará, Brazil. Eleven occurred in Barcarena and were confirmed by visualization of parasites on blood smears. Using cohort and case-control studies, we implicated oral transmission by consumption of açaí palm fruit.

Desire for a child among women living with HIV/AIDS in northeast Brazil.

In Brazil, an increasing proportion of new HIV infections and AIDS cases involve women of reproductive age. To describe the reproductive desire of women with HIV/AIDS and to identify factors associated with the desire for motherhood, a cross-sectional study was carried out in the referral hospital for infectious diseases in Ceará State, northeast Brazil. In total, 229 women were included in data analysis. Median age was 32 years (interquartile range, 26-37), and 63% had a monthly family income of less than 210 USD. Forty-nine percent were using a contraceptive method, and 37% wished to undergo tubal ligation. Sixty-four percent of the latter women were motivated by the fear of having an HIV-positive child. Forty percent of the participants wanted to have a child. In the multivariate regression analysis, variables independently associated with women's desire to have a child were: younger age (in years, odds ration [OR] = 0.94; 95% confidence interval [CI]: 0.90-0.98), number of children (OR = 0.73; 95% CI: 0.57-0.96), and partner's desire for a child (OR = 3.35; 95%CI: 1.75-6.39). Having a partner who did not know about the woman's positive serostatus was negatively associated with the woman's desire for a child (OR = 0.17; 95% CI: 0.04-0.69). No variable related to clinical status was significantly associated with the outcome variable. Our data showed that many unsterilized HIV-positive women in northeast Brazil, at whatever stage of illness, have a desire for children. We recommend that nondirective counseling, consisting of helping women evaluate their own feelings, goals and needs with respect to reproductive options be provided.