* treating physician judges patient not appropriate for study participation for any reason * age \<18 * breastfeeding or pregnancy (patient-reported pregnancy status is sufficient) * hypersensitivity to chloroquine or hc or az * history of or known qt prolongation * ekg required before study entry and on each visit during the subject's first seven days on pro-tocol, during the time period hc is being taken * baseline qtc \>480 if qrs width normal; qtc \>510 if qrs \>120 * known g6pd deficiency, porphyria, or retinopathy (eye exam prior to study entry) * known hepatic or renal disease (or abnormality on liver or renal function testing at study day 1) * low magnesium or low potassium (by testing on day 1) * current (pre-study) therapy with antimalarial or dapsone * current (pre-study) therapy with antiviral agents (e.g. oseltamivir) * tisdale36 score exceeding 6 as tallied below (based on acc recommendations)\* * 1 point each: age\>67, female sex, or being on loop diuretic * 2 points each: serum potassium \<3.6, qtc\>449, acute myocardial infarction * 3 points each: sepsis, heart failure, qt-prolonging drugs

* treating physician judges patient not appropriate for study participation for any reason * age \<18 * breastfeeding or pregnancy (patient-reported pregnancy status is sufficient) * hypersensitivity to chloroquine or hc or az * history of or known qt prolongation * ekg required before study entry and on each visit during the subject's first seven days on pro-tocol, during the time period hc is being taken * baseline qtc \>480 if qrs width normal; qtc \>510 if qrs \>120 * known g6pd deficiency, porphyria, or retinopathy (eye exam prior to study entry) * known hepatic or renal disease (or abnormality on liver or renal function testing at study day 1) * low magnesium or low potassium (by testing on day 1) * current (pre-study) therapy with antimalarial or dapsone * current (pre-study) therapy with antiviral agents (e.g. oseltamivir) * tisdale36 score exceeding 6 as tallied below (based on acc recommendations)\* * 1 point each: age\>67, female sex, or being on loop diuretic * 2 points each: serum potassium \<3.6, qtc\>449, acute myocardial infarction * 3 points each: sepsis, heart failure, qt-prolonging drugs

- treating physician judges patient not appropriate for study participation for any reason - age <18 - breastfeeding or pregnancy (patient-reported pregnancy status is sufficient) - hypersensitivity to chloroquine or hc or az - history of or known qt prolongation - ekg required before study entry and on each visit during the subject's first seven days on pro-tocol, during the time period hc is being taken - baseline qtc >480 if qrs width normal; qtc >510 if qrs >120 - known g6pd deficiency, porphyria, or retinopathy (eye exam prior to study entry) - known hepatic or renal disease (or abnormality on liver or renal function testing at study day 1) - low magnesium or low potassium (by testing on day 1) - current (pre-study) therapy with antimalarial or dapsone - current (pre-study) therapy with antiviral agents (e.g. oseltamivir) - tisdale36 score exceeding 6 as tallied below (based on acc recommendations)* - 1 point each: age>67, female sex, or being on loop diuretic - 2 points each: serum potassium <3.6, qtc>449, acute myocardial infarction - 3 points each: sepsis, heart failure, qt-prolonging drugs

- treating physician judges patient not appropriate for study participation for any reason - age <18 - breastfeeding or pregnancy (patient-reported pregnancy status is sufficient) - hypersensitivity to chloroquine or hc or az - history of or known qt prolongation - ekg required before study entry and on each visit during the subject's first seven days on pro-tocol, during the time period hc is being taken - baseline qtc >480 if qrs width normal; qtc >510 if qrs >120 - known g6pd deficiency, porphyria, or retinopathy (eye exam prior to study entry) - known hepatic or renal disease (or abnormality on liver or renal function testing at study day 1) - low magnesium or low potassium (by testing on day 1) - current (pre-study) therapy with antimalarial or dapsone - current (pre-study) therapy with antiviral agents (e.g. oseltamivir) - tisdale36 score exceeding 6 as tallied below (based on acc recommendations)* - 1 point each: age>67, female sex, or being on loop diuretic - 2 points each: serum potassium <3.6, qtc>449, acute myocardial infarction - 3 points each: sepsis, heart failure, qt-prolonging drugs